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ASERNIP S Australian Safety and Efficacy Register of New Interventional Procedures - Surgical Systematic Review Bioengineered Skin Substitutes for the Management of Burns: A Systematic Review ASERNIP-S REPORT NO. 46 August 2006 Australian Safety & Efficacy Register of New Interventional Procedures – Surgical The Royal Australasian College of Surgeons - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Bioengineered skin substitutes for the management of burns: a systematic review ISBN 0 909844 75 5 Published August 2006 This report should be cited in the following manner: Pham CT, et al. Bioengineered skin substitutes for the management of burns: a systematic review. ASERNIP-S Report No. 46. Adelaide, South Australia: ASERNIP-S, August 2006. Copies of these reports can be obtained from: ASERNIP-S PO Box 553, Stepney, SA 5069 AUSTRALIA Ph: 61-8-8363 7513 Fax: 61-8-8362 2077 E-Mail: [email protected] http://www.surgeons.org/asernip-s - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - The Safety and Efficacy Classification for the Systematic Review of Bioengineered Skin Substitutes for the Management of Burns was ratified by: The ASERNIP-S Management Committee on July 31, 2006 and The Council of the Royal Australasian College of Surgeons on August 26, 2006 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Table of Contents Executive Summary .......................................................................................... vi The ASERNIP-S Classification System............................................................. x The ASERNIP-S Review Group ...................................................................... xii 1. Introduction ............................................................................................... 1 Objective...............................................................................................................................1 Context..................................................................................................................................1 Background ..........................................................................................................................2 Burns ...............................................................................................................................2 Burn management ...............................................................................................................4 Wound dressings and topical agents...........................................................................5 Biological skin replacements ........................................................................................5 Bioengineered skin substitutes.....................................................................................6 Summary ...............................................................................................................................8 2. Methods.....................................................................................................12 Literature Search Protocol .............................................................................................. 12 Inclusion Criteria ........................................................................................................ 12 Literature Searches Strategies ......................................................................................... 14 Databases Searched and Search Terms Used ......................................................... 14 Methods of the Review.................................................................................................... 15 Literature Database .................................................................................................... 15 Ongoing and unpublished trials ............................................................................... 17 Data Extraction........................................................................................................... 17 Data Analysis............................................................................................................... 17 3. Studies Included in the Review ................................................................19 Designation of Levels of Evidence and Critical Appraisal......................................... 19 Description of studies................................................................................................ 19 4. Results ...................................................................................................... 28 Efficacy .............................................................................................................................. 28 Biobrane® ................................................................................................................... 28 TransCyte® ................................................................................................................. 32 Dermagraft® ............................................................................................................... 34 i - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Integra®........................................................................................................................36 Apligraf®......................................................................................................................38 Autologous cultured skin ...........................................................................................39 Allogeneic cultured skin .............................................................................................41 Complications ....................................................................................................................44 Biobrane® ....................................................................................................................44 TransCyte® ..................................................................................................................45 Dermagraft®................................................................................................................45 Integra®........................................................................................................................45 Apligraf®......................................................................................................................46 Autologous cultured skin ...........................................................................................46 Allogeneic cultured skin .............................................................................................46 Mortality .............................................................................................................................47 Biobrane® ....................................................................................................................47 Biobrane® ....................................................................................................................47 TransCyte® ..................................................................................................................47 Dermagraft®................................................................................................................47 Integra®........................................................................................................................47 Apligraf®......................................................................................................................48 Autologous cultured skin ...........................................................................................48 Allogeneic cultured skin .............................................................................................48 Cost considerations...........................................................................................................49 5. Discussion ................................................................................................ 50 Limitations of the evidence .............................................................................................50 Efficacy outcomes.............................................................................................................51 Biobrane® ....................................................................................................................51 TransCyte® ..................................................................................................................52 Dermagraft®................................................................................................................53 Integra®........................................................................................................................53 Apligraf®......................................................................................................................54 Autologous cultured skin ...........................................................................................54 Allogeneic cultured skin .............................................................................................54 Biological skin replacements......................................................................................55 Safety outcomes.................................................................................................................55 ii - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Cost considerations .......................................................................................................... 56 Ethical considerations...................................................................................................... 56 Future research ................................................................................................................. 56 6. Conclusions and Recommendations ....................................................... 58 Acknowledgments ............................................................................................................ 60 References .........................................................................................................61 Appendix A – Hierarchy Of Evidence.......................................................................... 68 Appendix B – Excluded Studies..................................................................................... 70 Appendix C – Methodological Assessment and Study Design Tables..................... 77 Appendix D – Mean Total Burn Surface Area for Included Studies ....................... 99 iii - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - List of Tables Table 1. Classification of available skin substitutes ...........................................................9 Table 2. Databases searched................................................................................................14 Table 3. Summary of included randomised controlled trials*........................................20 Table 4. Losses to follow-up in Biobrane® for burn management studies .................22 Table 5. Losses to follow-up in Dermagraft® for burn management studies.............24 Table 6. Losses to follow-up in Integra® for burn management studies.....................25 Table 7. Losses to follow-up in Apligraf® for burn management studies...................26 Table 8. Wound healing time for burns managed with Biobrane® and comparators29 Table 9. Number of wounds requiring skin grafting to close the wound.....................29 Table 10. Wound pain scores for burns managed with Biobrane® and comparators30 Table 11. Wound healing time (days) for donor sites managed with Biobrane® and comparators: part 1...............................................................................................................31 Table 12. Wound healing time (days) for donor sites managed with Biobrane® and comparators: part 2...............................................................................................................31 Table 13. Percentages of sites completely healed by Day 32..........................................31 Table 14. Scar severity (mean scores) for Biobrane® versus OrCel™.........................32 Table 15. Wound infection for burns managed with TransCyte® and comparators .33 Table 16. Wound healing time for burns managed with TransCyte® and comparators .................................................................................................................................................33 Table 17. Wound pain scores for burns managed with TransCyte® and topical antibiotics ...............................................................................................................................34 Table 18. Percent graft take for burns managed with Dermagraft® and allograft .....36 Table 19. Proportion of patients with ≥75% wound closure for Integra® and comparators ...........................................................................................................................37 Table 20. Proportion of patients with ≥75% wound closure for Apligraf® and autograft .................................................................................................................................38 Table 21. Other patient-related outcomes for Waymack 2000 (n=40).........................39 iv - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Table 22. Wound closure, graft take and number of patients requiring skin grafting 40 Table 23. Other patient-related outcomes for Boyce 2002 (n=45) .............................. 41 Table 24. Wound healing time (mean days) for donor sites managed with an allogeneic cultured skin and comparators......................................................................... 42 Table 25. Percentage of epithelialisation for donor sites managed with allogeneic cultured keratinocyte sheets and OpSite® ....................................................................... 43 Table 26. Breakdown of cost information from Demling & DeSanti 2002................ 49 v - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Executive Summary Objective To assess the safety and efficacy of bioengineered skin substitutes in comparison with biological skin replacements and/or standard dressing methods in the management of burns, through a systematic review of the literature. Methods Search strategy – Studies were identified by searching MEDLINE, EMBASE, The Cochrane Library, Science Citation Index and Current Contents from inception to April 2006. The Clinical Trials Database (US), NHS Centre for Research and Dissemination, NHS Health Technology Assessment (UK), National Research Register (UK), National Institute of Health (US) and Meta Register of Controlled Trials were also searched in April 2006. Study selection – Only randomised controlled trials in humans were included for review. Efficacy outcomes included wound infection, wound closure, wound healing time, and wound exudate. Patient-related outcomes included pain and cosmesis. Safety outcomes included complications and mortality. Data collection and analysis – Data from the included studies was extracted by an ASERNIP-S researcher using standardised data extraction tables developed a priori and checked by a second researcher. Statistical pooling was not appropriate due to the study and result heterogeneity. Results A total of 20 randomised controlled trials were included in this review. Due to the diversity of skin substitutes and methods for burn management and the way in which outcomes were reported in the included studies, it was not possible to investigate differences in the effectiveness of bioengineered skin substitutes in partial thickness compared with full thickness burns, in paediatric patients compared to adult patients, and for TBSA. However, from the available evidence it was possible to draw some conclusions about the different bioengineered skin substitutes considered in the review. For partial thickness burns (less than 15%TBSA), Biobrane® and TransCyte® appear to be more effective than silver sulfadiazine, avoiding the need for painful daily dressing changes and prolonged hospital stay. Biobrane® may also offer cost advantages over other bioengineered skin substitutes. vi - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - For burns between 20% and 50% TBSA, allogeneic cultured skin and Apligraf® combined with autograft both appear to be effective. Dermagraft® was also found to be effective for partial and full thickness burns (as effective as allograft); however, the validity of this comparison is questionable as Dermagraft® is permanently integrated whereas allograft is a temporary biological dressing. Integra® may be better suited to selected patients with burns less than 45% TBSA due to the high rates of infection reported in one study managing patients with burns greater than 45% TBSA. However, in clinical practice, Integra® is commonly used in the treatment of major burn injury where a paucity of available donor area precludes early autografting. Its successful take still has to be followed by definitive epidermal closure (by autograft or cultured epithelial autograft). TransCyte® appears to be good for facial burns, providing good adherence to the contours of the face. However, considerations with the storage, pre-use preparation and high cost of TransCyte® may limit its clinical use. In terms of safety, no major complications were reported with the use of bioengineered skin substitutes for the management of burns or donor sites. The mortality rate was relatively high; however, it was unclear whether these deaths could be attributed to the use of the bioengineered skin substitute or the actual burn injury. In practical terms, this distinction would be difficult to assess since the use of bioengineered skin substitutes is largely confined to patients with larger TBSA burn areas, more complicated pathophysiological insults and significantly poorer prognoses. The available evidence could not resolve the question of the long-term safety of bioengineered skin substitutes with respect to viral infection and prion disease. Thus, at present, autograft remain the gold standard for the management of excised burns as it is effective at closing the wound and there are no issues with graft rejection and viral contamination. Classification and Recommendations On the basis of the evidence presented in this systematic review, the ASERNIP-S Review Group agreed on the following classifications and recommendations concerning the safety and efficacy of bioengineered skin substitutes for the management of burns: Classifications Evidence rating The evidence-base in this review is rated as average. The included randomised controlled trials were limited by small sample size and poor reporting of methodological detail. The numerous sub-group analyses and the diversity of skin substitutes limited the ability to draw any conclusions from it. vii - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Safety The evidence suggests that bioengineered skin substitutes, namely Biobrane®, TransCyte®, Dermagraft®, Apligraf®, autologous cultured skin, and allogeneic cultured skin, are at least as safe as biological skin replacements or topical agents/wound dressings. The safety of Integra® could not be determined as one study reported a high rate of infection and the trial was terminated early. The long-term safety of the use of bioengineered skin substitutes, with respect to viral infection and prion disease, could not be determined. Efficacy For the management of partial thickness burns, the evidence suggests that bioengineered skin substitutes, namely Biobrane®, TransCyte®, Dermagraft®, and allogeneic cultured skin, are at least as efficacious as topical agents/wound dressings or allograft. Apligraf® combined with autograft is at least as efficacious as autograft alone. For the management of full thickness burns, the efficacy of autologous cultured skin could not be determined based on the available evidence. The efficacy of Integra® could not be determined based on the available evidence. Clinical and Research Recommendations Additional methodologically rigorous randomised controlled trials would strengthen the evidence base for the use of bioengineered skin substitutes. However, it is acknowledged that it is unlikely that randomised trials of patients with large, deep burns will be carried out, as these burns are uncommon and usually involve complex clinical decision pathways and possibly the use of several products, which may differ between patients and make comparisons difficult. Therefore, it is recommended that randomised trials of patients with smaller burns be undertaken as these burns are more common and patient accrual should be easier. Furthermore, clinical equipoise should be more easily obtained in these less life-threatening situations. Additionally, studies with sufficient follow-up should be conducted to evaluate the long-term safety of bioengineered skin substitutes and future studies should define and document outcomes for partial and full thickness burns separately. There is also a need for randomised controlled trials on cultured epithelial autograft, in particular cultured epithelial autograft suspensions, as there is a lack of evidence to support its safety and efficacy and its use largely based on anecdote. Important note The information contained in this report is a distillation of the best available evidence located at the time the searches were completed as stated in the protocol. Please viii - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - consult with your health care professional if you have further questions relating to the information provided, as the clinical context may vary from patient to patient. ix - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - The ASERNIP-S Classification System Evidence Rating The evidence for ASERNIP-S systematic reviews is classified as Good, Average or Poor, based on the quality and availability of this evidence. High quality evidence is defined here as having a low risk of bias and no other significant flaws. While high quality randomised controlled trials are regarded as the best kind of evidence for comparing interventions, it may not be practical or ethical to undertake them for some surgical procedures, or the relevant randomised controlled trials may not yet have been carried out. This means that it may not be possible for the evidence on some procedures to be classified as good. Good Most of the evidence is from a high quality systematic review of all relevant randomised trials or from at least one high quality randomised controlled trial of sufficient power. The component studies should show consistent results, the differences between the interventions being compared should be large enough to be important, and the results should be precise with minimal uncertainty. Average Most of the evidence is from high quality quasi-randomised controlled trials, or from non-randomised comparative studies without significant flaws, such as large losses to follow-up and obvious baseline differences between the comparison groups. There is a greater risk of bias, confounding and chance relationships compared to high-quality randomised controlled trials, but there is still a moderate probability that the relationships are causal. An inconclusive systematic review based on small randomised controlled trials that lack the power to detect a difference between interventions and randomized controlled trials of moderate or uncertain quality may attract a rating of average. Poor Most of the evidence is from case series, or studies of the above designs with significant flaws or a high risk of bias. A poor rating may also be given if there is insufficient evidence. x - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Safety and Efficacy Classification Safety At least as safe compared to comparator* procedure(s) This grading is based on the systematic review showing that the new intervention is at least as safe as the comparator. Safety cannot be determined This grading is given if the evidence is insufficient to determine the safety of the new intervention. Less safe compared to comparator* procedure(s) This grading is based on the systematic review showing that the new intervention is not as safe as the comparator. Efficacy At least as efficacious compared to comparator* procedure(s) This grading is based on the systematic review showing that the new intervention is at least as efficacious as the comparator. Efficacy cannot be determined This grading is given if the evidence is insufficient to determine the efficacy of the new intervention. Less efficacious compared to comparator* procedure(s) This grading is based on the systematic review showing that the new intervention is not as efficacious as the comparator. Research Recommendations It may be recommended that an audit or a controlled (ideally randomised) clinical trial be undertaken in order to strengthen the evidence base. Clinical Recommendations Additional recommendations for use of the new intervention in clinical practice may be provided to ensure appropriate use of the procedure by sufficiently qualified/ experienced centres and on specific patient types (where appropriate). * A comparator may be the current ‘gold standard’ procedure, and alternative procedure, a nonsurgical procedure or no treatment (natural history) xi - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - The ASERNIP-S Review Group ASERNIP-S Director Professor Guy Maddern ASERNIP-S Royal Australasian College of Surgeons Stepney SA 5069 Protocol Surgeon Mr John Greenwood Director of Burns Unit, Royal Adelaide Hospital North Terrace Adelaide SA 5000 Advisory Surgeon Dr Heather Cleland Director of Burns Unit, The Alfred Hospital Elizabeth Street Melbourne VIC 3000 Other Specialty Surgeon Associate Professor Peter Woodruff Vascular Surgical Unit Princess Alexandra Hospital Woolloongabba QLD 4102 ASERNIP-S Researcher Ms Clarabelle Pham ASERNIP-S Royal Australasian College of Surgeons Stepney SA 5069 Conflict of Interest None of the authors declared a conflict of interest. xii - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - 1. Introduction Objective To assess the safety and efficacy of bioengineered skin substitutes in comparison with biological skin replacements and/or standard dressing methods in the management of burns, through a systematic review of the literature. Context Burn injuries are amongst the most complex and harmful physical injuries to evaluate and manage. In addition to pain and distress, a large burn injury will leave the patient with visible physical scars and invisible psychological sequelae. Bioengineered skin substitutes have been developed as an adjunct or alternative to the use of the patient’s own skin (autograft), the current gold standard (Jones et al. 2002). They are designed to close the wound, temporarily or permanently, providing a mechanical barrier to infection and fluid loss. They also possess various biological and pharmacological properties of human skin which allow and/or promote new tissue growth and optimise the conditions for healing (Demling et al. 2000). In Australia and New Zealand, approximately 1% of the population sustain burn injuries annually (~220 000 people) (Australia and New Zealand Burn Association Ltd. 1996). Of these, 50% will suffer restriction of their activities of daily living (~110 000 people), 10% of those will require admission to hospital (~10 000 people) and 10% of those will have burn injuries sufficiently severe to threaten life (~1000 people) (Australia and New Zealand Burn Association Ltd. 1996). In the United Kingdom, approximately 0.42% of the population (~250 000 people) are burnt annually with about 70% (~175 000 people) attending accident and emergency departments and about 5% (~12 500) being admitted to hospital (Hettiaratchy and Dziewulski 2004). The type and severity of burn will determine the management required. Management of superficial burns involves the use of antibacterial topical agents, dressings and certain biosynthetic skin substitutes (epidermal replacements). However, for major deep burns, management involves surgical debridement of the burn wound and the additional use of autograft with or without other biological skin replacements (allografts or xenografts) and bioengineered skin substitutes (biosynthetic skin substitutes and autologous cultured/non-cultured skin engineering products). The use of bioengineered skin substitutes is usually mandated by a deficiency of autograft. However, there is uncertainty about the safety and effectiveness of the various types of skin substitutes available. SECTION 1 z INTRODUCTION 1 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Background Burns Skin is the largest organ in the human body (Balasubramani et al. 2001). It consists of a thin, cellular, superficial layer - the epidermis - which acts as a barrier against infection and moisture loss, and a thick, deeper layer - the dermis - which is responsible for the elasticity and mechanical integrity of skin. The dermis contains adenexal structures and blood vessels responsible for the health and nutrition of the epidermal cells (Jones et al. 2002) (see Figure 1). Figure 1. The layers of the skin If the dermis is exposed through a burn injury, the body’s innate wound healing cascade is activated. Wound healing is a complex process with four main overlapping phases (Hunt et al. 2000): 1. Coagulation – begins immediately after injury. Platelets are involved in the release of cytokines and mediators which stimulate epidermal cell proliferation and attract early debriding cell populations such as neutrophils into the wound. 2. Inflammation – may last from a few days to weeks. Macrophages are involved in the release of chemical messengers that stimulate angiogenesis (necessary to re-establish a blood supply to the wound). Any factor which leads to prolongation of the inflammatory phase will result in worsening of the scar result; functionally, cosmetically and symptomatologically. 2 SECTION 1 z INTRODUCTION - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - 3. Proliferation and cell migration – periwound keratinocytes, and any surviving keratinocyte nests around adenexal structures within the wound, rapidly divide to increase their numbers. Their migration across the wound results in epithelialisation, re-establishing the epidermal barrier. The interaction of collagen and fibroblasts results in wound contraction reducing the distance that epithelial cells need to migrate to effectively complete epithelialisation. 4. Remodelling (maturation) – may last up to two years. This process of scar tissue formation is facilitated by the presence of intermatrix ground substances, glycosaminoglycans and proteoglycans, which maintain hydration and support to the neo-collagen. The agents capable of causing burn injuries are many and varied but can broadly be placed into one of five groups: heat, cold, electricity, chemicals and ionising radiation (Hettiaratchy and Dziewulski 2004). Treatment will depend on the burn depth (see Figure 2). Burn injury depth is classified as follows (Papini 2004): Epidermal burns – cell death affects only the epidermal cells. These rapidly dividing cell populations are capable of regeneration and, as such, these injuries heal spontaneously and without scarring. Superficial to mid partial thickness burns – affects the epidermis and upper dermis. Healing again is spontaneous. Any injury involving the dermis generates scar tissue, but in the more superficial cases the scar is almost unnoticeable. Deep partial thickness burns – all epidermal cell nests capable of proliferation are lost, the healing process is slower and involves contraction if injuries are extensive or in functionally or cosmetically sensitive areas. Full thickness burns – all elements essential for skin regeneration have been destroyed; contraction is marked, healing very slow and scarring unacceptable. The products used to manage each burn wound will differ and depend on the depth of the burn. For epidermal to superficial-mid partial thickness burns, a skin substitute may be used as a definitive treatment and to potentially circumvent the need for autografting. For deep partial to full thickness burns, a skin substitute will be used as a temporised matrix when there is no alternative or as a material to hold the skin graft in place. SECTION 1 z INTRODUCTION 3 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Figure 2. Burn depth Burn management The principle of burn management is to allow superficial burns to heal whilst minimising discomfort, avoiding infection and producing no or negligible scar. 4 SECTION 1 z INTRODUCTION - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Generally, burn injuries to the epidermis alone, or with a superficial amount of dermis, will heal spontaneously and require only conservative management with wound dressings and/or topical agents. However, deep dermal burns have a protracted healing course which results in significant scarring and full thickness burns (other than small injuries) are unlikely to heal spontaneously because the epidermal cell nests responsible for re-epithelialisation are lost and there is deep destruction of dermal collagen. Surgical management of deep burns involves the removal of nonviable, burn-injured tissue and permanently closing the burn wound in a timely fashion designed to generate the best cosmetic, functional and symptomatological result. Wound dressings and topical agents A variety of wound dressings are available which can be used alone, if appropriate, or with topical agents. The properties of these dressing materials differ and include (Demling et al. 2000): antibacterial (to control infection) absorbency (to control heavily exuding wounds) non-adhesiveness (designed to not stick to the wound, thus minimising discomfort on dressing changes) occlusion/semi-occlusion (designed to provide a healing environment for a clean, minimally exudative wound, whilst preventing bacterial contamination and protecting the surrounding uninvolved tissue from wound exudate). For the treatment of burns, antibacterial topical agents such as nanocrystalline silver (impregnated in Acticoat™ dressings) (Dunn and Edwards-Jones 2004), silver sulfadiazine (Dunn and Edwards-Jones 2004) and mafenide acetate (Brown et al. 2004) are used in the acute phase where there has been considerable contamination of the burn wound, or where a lengthy delay is expected before the patient can expect to receive definitive burn treatment. These topical agents and wound dressings are only used to cover the wound and provide a warm, moist environment, conducive to wound healing. They cannot ‘close’ the wound like skin replacements/substitutes. Biological skin replacements Biological skin replacements are defined as materials derived from wholly biological sources. The gold standard for surgical repair after excision of a burn wound is the use of a skin graft harvested from the patient’s own undamaged skin (an autograft). Alternatively, if autograft is scarce, cadaver skin (an allograft) or a graft derived from animal skin products (a xenograft) may be used to temporarily close and modulate the wound bed. SECTION 1 z INTRODUCTION 5 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Of these, only autograft usually remains permanently. As allografts and xenografts are allogeneic, they are rejected after a variable period and therefore can only be used as a biological dressing until spontaneous skin repair occurs or definitive skin replacement becomes available. Occasionally, dermal elements of cadaver allograft may remain permanently. The supply of cadaver skin is provided by registered, regulated skin banks. The availability of cadaver skin is limited by the geographical location of skin banks, the expense of processing and storage, and the potential difficulties associated with emergency transport of such materials when needed. Their desirability may be reduced by the potential for disease transmission (particularly prion-related) and the quality of the material after the cryopreservation process (Eisenbud et al. 2004). Currently, there are only two skin banking facilities that are licensed by the Therapeutic Goods Administration (TGA) to provide human skin allografts; the Donor Tissue Bank of Victoria and the Auckland Skin Bank, which operates under the auspices of the New Zealand Red Cross Blood Transfusion Service (Hancock 1999). Porcine skin products are the most commonly used xenografting materials, particularly de-epidermised dermis such as EZ Derm™ (Brennen Medical, Inc., St. Paul, Minnesota, USA). They are more readily available than cadaver allograft, but their use is restricted to partial thickness burns (Demling et al. 2000). However, the beliefs of certain religions must be considered when planning the use of these materials. Although used on a widespread basis in the USA and Europe, they are not yet licensed in Australia (J Greenwood: personal communication, 2005). Bioengineered skin substitutes Bioengineered skin substitutes have been designed to offer therapeutic alternatives that are readily available and have some of the biological and pharmacological properties of human skin (Herman 2002). There are two main categories of bioengineered skin substitutes; biosynthetic skin substitutes and autologous cultured and non-cultured skin engineering products. Table 1 is a summary and taxonomy of skin substitutes available in Australia and internationally. Biosynthetic skin substitutes The biosynthetic skin substitutes are a family of materials which have been developed to mimic a function of the skin and are designed to be used in situations when full or variable thicknesses of skin have been lost (Eisenbud et al. 2004). Some are designed to replace the functions of the epidermis, some to replace the functions of the dermis and some to replace the functions of both epidermis and dermis. Most are for use temporarily as highly specialised dressings to replace skin functions until the skin barrier repairs spontaneously, or to ‘buy time’ until definitive skin replacement is possible with autograft or cultured equivalent. Epidermal substitutes allow re-epithelialisation to occur while permitting gas and fluid exchange, providing 6 SECTION 1 z INTRODUCTION - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - both protection from bacterial ingress and mechanical coverage (aiding relief from discomfort). A small number are designed to permanently incorporate into the debrided wound, for example, by generating a neo-dermis. This large group of materials may be completely synthetic in their composition but most have some biological element incorporated into them (Demling et al. 2000). There are a large number of biosynthetic skin substitutes available worldwide; however, in Australia only Biobrane®, TransCyte® and Integra® are available (see Table 1). Of these, TransCyte® and Integra® are licensed by the Therapeutic Goods Administration (TGA) and are freely available. Smith & Nephew Pty. Ltd. have recently placed the manufacturer of TransCyte® (Advanced Tissue Sciences, Inc., La Jolla, CA, USA) on the market and as a result, it is expected that no new stock of TransCyte® will be available from the beginning of 2006. Biobrane® is also available via the Special Access Scheme (Therapeutic Goods Administration 2004a) requiring yearly reapplication for permission to use an unapproved product (J Greenwood, personal communication 2005). Autologous cultured and non-cultured skin engineering products In an attempt to address the expense and other disadvantages of allografts and xenografts, methods for expanding the patient’s own cell populations have been developed. Since 1975, a process for the culture of keratinocytes has been available (Rheinwald and Green 1975). Keratinocytes are rapidly dividing epidermal cells and, by sacrificing a small sample biopsy of uninjured skin, huge numbers of keratinocytes can be grown in a relatively short time. Cultured and non-cultured skin engineering products are a rapidly growing group of materials in which techniques have been employed to expand available autograft, either by creating cultured keratinocyte sheets or suspensions, or enzymatically generating non-cultured epithelial cell suspensions (Eisenbud et al. 2004). Keratinocyte replacements require dermal support and as such, they are at present used in an attempt to facilitate rapid reepithelialisation in superficial partial thickness burns (where dermal elements are uninjured), as an adjunct to meshed autograft, or over bioengineered neo-dermis. Many centres are working towards engineered composite skin replacement utilising a molecular scaffold (e.g. fibrin, fibronectin, vitronectin, or collagen) seeded with autologous fibroblasts. This arrangement allows these cells to create an ‘autologous’ neo-dermis onto the ‘outer surface’ of which can be cultured autologous keratinocytes. Though the use of autologous cells is immunologically safe, there are issues with cost, short shelf-life, fragility and the need for custom preparation (Eisenbud et al. 2004). Cultured keratinocytes are now listed as a Class 3 Human Cell, Tissue and Cellular and Tissue-Based Products, where laboratories manufacturing such products are inspected, audited, licensed and regulated with subsequent monitoring (Therapeutic Goods Administration 2004b). The Therapeutic Goods Administration’s Special Access Scheme offers arrangements to provide for the import and/or supply of an SECTION 1 z INTRODUCTION 7 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - unapproved therapeutic good, such as cultured keratinocytes, for a single patient, on a case by case basis (Therapeutic Goods Administration 2004a). Enzyme-generated autologous non-cultured keratinocyte/melanocyte products and are Class 1 Human Cell, Tissue and Cellular and Tissue-Based Products (i.e. unregulated products), as they are produced completely within the operating theatre during the operative procedure and involves no transport of tissue out of the operating theatre (Therapeutic Goods Administration 2004a). Summary Currently autograft is the best replacement for lost skin. In clinical practice this is not always possible, particularly in large total body surface area burns, as there is often an insufficient amount of skin for autografting available at the time of burn excision or the physiological condition of the patient precludes the harvesting of skin. Allografts and xenografts can be used as temporary wound coverage but there are issues with graft rejection, availability, cultural and ethical implications and the possibility of disease transfer. Biosynthetic skin substitutes provide immediate wound cover, are available in large quantities and have a negligible risk of cross-infection (potentially associated with the use of allografts and xenografts). Furthermore, the use of autologous cells in the cultured skin products has the advantage of immunological safety. However, most skin substitutes are expensive and considerable experience is required to decide which material is appropriate for any given situation. No skin substitute, other than full thickness autograft, replaces all lost skin elements. Due to the rapid proliferation of bioengineered skin substitutes there is uncertainty regarding their safety and effectiveness in comparison with standard wound management, either with biological skin replacements or standard wound dressings. This uncertainty may be compounded if comparisons are made between different treatments without consideration of factors such as differences in the methods and timing of application of the product (for example at different time points post-injury when bacterial colonisation may be established). This review aims to assess the safety and efficacy of bioengineered skin substitutes, compared with biological skin replacements and/or standard dressing methods, in the management of burns, taking into consideration these factors whereever possible. 8 SECTION 1 z INTRODUCTION Table 1. Classification of available skin substitutes Classification Duration of Contact Tissue Replaced Layers Status in Australia Manufacturer Permanent Epidermal & Dermal Full or variable thickness Available Temporary Epidermal & Dermal Full or variable thickness Available EZ Derm™ Temporary Dermal Biosynthetic, acellular, xenogeneic (porcine) dressing Not Available Cutaneous Flaps Permanent Epidermal & Dermal Full or variable thickness Available Alloderm® Permanent Dermal Acellular, de-epithelialised cadaver dermis Not Available LifeCell, Woodlands, TX, USA Oasis™ Temporary Dermal Derived from porcine small intestinal submucosa Not Available Healthpoint Ltd., Fort Worth, TX, USA Promogran™ Temporary Dermal Bovine collagen & oxidised regenerated cellulose Not Available Johnson & Johnson, New Jersey, USA Temporary Epidermal Thin, transparent, synthetic polyurethane membrane Available ITG Laboratories, Inc., CA, USA Apligraf® Temporary Epidermal & Dermal 1. Neonatal keratinocytes 2. Collagen seeded with neonatal fibroblasts Only in clinical trials Organogenesis, Inc., Canton, MA, USA & Novartis Pharmaceuticals Corp., East Hanover, NJ, USA Biobrane® Temporary Epidermal 1. Silicone 2. Nylon mesh 3. Porcine polypeptides Available Dow Hickam/Bertek Pharmaceuticals, Sugar Land, TX, USA Biological Skin Replacements Grafts & Cutaneous Flaps Autograft Allograft Cadaver Skin Xenograft Brennen Medical, Inc., St. Paul, MN, USA Biosynthetic Skin Substitutes Biological Synthetic Omiderm® Mixed Table continued over … 9 10 Table 1. Classification of available skin substitutes (continued) Classification Duration of Contact Tissue Replaced Layers Status in Australia Manufacturer Dermagraft® Permanent Dermal Polyglycolic acid (Dexon™) or polyglactin-910 (Vicryl™) seeded with neonatal fibroblasts Not Available Only available in Canada & UK Used in clinical trials in the US Advanced Tissue Sciences, Inc., La Jolla, CA, USA Integra® Permanent Dermal 1. Silicone 2. Collagen & glycosaminoglycan Available Integra Life Science Corp., Plainsboro, NJ, USA OrCel™ Permanent Epidermal & Dermal Collagen (bovine type I) seeded with allogeneic fibroblasts & keratinocytes Not Available Ortec International, Inc., NY, USA TransCyte® Temporary Epidermal 1. Silicone 2. Nylon mesh 3. Collagen seeded with neonatal fibroblasts Available Advanced Tissue Sciences, Inc., La Jolla, CA, USA Hyalograft™ Permanent Dermal Cultured autologous fibroblasts on a biomaterial derived from hyaluronic acid Not Available Fidia Advanced Biopolymers, Italy Autologous Cultured and Non-Cultured Skin Engineering Products Cultured Keratinocytes Cellspray® Permanent Epidermal Spray on cultured epithelial autograft Available on case-by-case basis Clinical Cell Culture Ltd., Bentley, WA, Australia Epicel™ Permanent Epidermal Cultured autologous keratinocytes Not Available Genzyme Tissue Repair Corp., Cambridge, MA, USA EpiDex™ Permanent Epidermal Generated in vitro from the patient’s hair (the outer root sheath cells of hair follicle) Not Available Modex Therapeutiques, Lausanne, Switzerland Laserskin™ Permanent Epidermal 1. Cultured autologous keratinocytes 2. Hyaluronic acid with laser perforations Not Available Fidia Advanced Biopolymers, Italy (aka Vivoderm™ by ER Squibb & Sons, Inc.) Table continued over … Table 1. Classification of available skin substitutes (continued) Classification Duration of Contact Tissue Replaced Layers Status in Australia Manufacturer Non-Cultured Keratinocytes/Melanocytes ReCell® Permanent Epidermal Autologous cell harvesting kit Available Clinical Cell Culture Ltd., Bentley, WA, Australia Cellspray® XP Permanent Epidermal Spray on non-cultured epithelial autograft Available on case-by-case basis Clinical Cell Culture Ltd., Bentley, WA, Australia Disclaimer: Every effort has been made to correctly assign design details and company names to the prostheses listed in Table 1. 11 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - 2. Methods Literature Search Protocol Inclusion Criteria Articles were selected for inclusion in this systematic review on the basis of the following criteria: Participants Only studies in humans (adults and children) with burns (or donor sites used to treat burn wounds) suitable for treatment with bioengineered skin substitutes and reporting efficacy and/or safety data were included. New Intervention Biosynthetic skin substitutes Autologous cultured and non-cultured skin engineering products Comparative Intervention Biological skin replacements Standard methods (dressings and/or topical agents or compression therapy) **Studies of one kind of new intervention versus another were also included. Outcomes The studies included reported at least one of the following outcomes of the new or comparative interventions: Extent of wound healing which could include, but not be limited to: • Wound measurements • Rate of re-epithelialisation • Wound closure rate Acceptance or failure of graft which could include, but not be limited to: • Clinical take • Failure rate Convalescence of patients which could include, but not be limited to: • Length of hospital stay • Healing time Perioperative and postoperative morbidity and mortality of patients • Cosmesis (scarring) 12 SECTION 2 z METHODS - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - • Toxic/adverse effects Patient satisfaction factors which could include, but not be limited to: • patient satisfaction • pain Cost/resource use Types of studies Systematic reviews of randomised controlled trials (RCTs) and RCTs were included for review. Where appropriate, additional relevant published material in the form of letters, conference material, commentary, editorials and abstracts were included as background information. Language Restriction Searches were conducted without language restriction. Foreign language articles were subsequently excluded unless the findings provided additional information over that reported in well designed studies published in the English language. SECTION 2 z METHODS 13 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Literature Searches Strategies Databases Searched and Search Terms Used Searches are shown in Table 2. Table 2. Databases searched Database Platform Edition Current Contents Ovid Searched 01/04/2006 EMBASE Ovid Week 1 1980 to 11/04/2006 Cochrane Library Issue 2, 2006 MEDLINE Ovid 1966 to 11/04/2006 CINAHL Ovid 1982 to 10/04/2006 PubMed Entrez 1953 to 11/04/2006 Clinical Trials Database (US) Searched 12/04/2006 NHS CRD (UK) NHS HTA (UK) Searched 12/04/2006 National Research Register (UK) Issue 2, 2006 Current Controlled Trials (mRCT) Searched 12/04/2006 Search Terms Search terms used for The Cochrane Library: artificial AND skin Search terms used for the Clinical Trials Database, NHS CRD, NHS HTA, Current Controlled Trials and the National Research Register: burns AND tissue engineer* OR bioengineer* OR biosynthetic OR keratinocytes Search terms used for MEDLINE, EMBASE, CINAHL, PubMed and Current Contents: burns [MeSH] AND (tissue engineer$ OR bioengineer$ OR biosynthetic OR artificial) OR ((human OR living) AND skin equivalent) OR keratinocytes OR artificial skin [MeSH] In MEDLINE and PubMed limit by publication type: randomized controlled trial OR Xenoderm 14 SECTION 2 z METHODS - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - OR Epicel OR Laserskin OR Vivoderm OR EpiDex OR Alloderm OR TransCyte OR Apligraf OR Dermagraft OR Oasis OR E-Z-Derm OR OrCel OR Biobrane OR Integra OR Promogran OR Cellspray OR Recell OR Hyalograft Note: * is a truncation character that retrieves all possible suffix variations of the root word e.g. surg* retrieves surgery, surgical, surgeon, etc. In Cochrane the truncation character is *; in Current Contents, EMBASE, CINAHL and MEDLINE (Ovid) it is $. # is a wildcard symbol that substitutes for one required character in Current Contents, EMBASE, CINAHL and MEDLINE (Ovid). Methods of the Review Literature Database Articles were retrieved if they were judged to possibly meet the inclusion criteria based on their abstracts. Two ASERNIP-S Researchers independently applied the selection criteria and any differences were resolved through discussion. The number of articles retrieved for each search category is listed in Figure 1. In some cases, when the full text of the article was retrieved, closer examination revealed that it did not meet the inclusion criteria specified by the review protocol. Consequently these papers were not used to formulate the evidence base for the systematic review (see Figure 1 and Appendix B). However, relevant information contained in these excluded papers was used to inform and expand the review discussion. The bibliographies of all publications retrieved were manually searched for relevant references that may have been missed in the database search (pearling). SECTION 2 z METHODS 15 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Figure 1. Process for selection of studies retrieved from the literature databases Potentially relevant citations identified as a result of the electronic and internet searches (n=166) Citations that provided general background information (n=78) Citations excluded after application of inclusion criteria (n=39) Studies retrieved for more detailed evaluation (n=49) Citations excluded after detailed evaluation (n=30) Initial relevant studies included in systematic review (n=19) References of these included studies were “pearled”. 7 relevant references were retrieved for more detailed evaluation. 1 study met the inclusion criteria. Relevant studies included in systematic reviews (n=20) Donor site treatment (n=4) 16 Burns treatment (n=16) SECTION 2 z METHODS - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Ongoing and unpublished trials Searches of the Clinical Trials Database, NHS CRD, NHS HTA, Current Controlled Trials and the National Research Register identified one RCT in progress and two unpublished RCTs. The details for each are provided below. RCT in progress Greenwood J. Adelaide, Australia: The use of melanocyte/keratinocyte cosuspension for the repigmentation of amelanotic patches in vitiligo. This randomised controlled trial is in its final stages of investigating the effectiveness of CellStat on surgically dermabraded apigmented wounds in vitiligo patients. It is hoped that the results of this trial will determine the potential of CellStat for the management of burns. Start Date: January 2005. Unpublished RCTs Myers S. Essex, UK: A randomised prospective comparison of Mepitel® and Biobrane® in the treatment of paediatric partial thickness burn injury. Outcome measures included: pain scores, time to healing, in-patient stay, hypertrophic scar rate, and infective episodes. Start Date: March 2001. End Date: March 2002. Freedlander E. Sheffield, UK: A randomised controlled trial of the effectiveness and cost-effectiveness of Integra® in the management of severe burns. Outcome measures included: length of stay, morbidity and mortality. Start Date: June 1999. End Date: February 2003. Data Extraction Data from all included studies were extracted by one researcher and checked by a second using standardised data extraction tables that were developed a priori. Data were only reported if stated in the text, tables, graphs or figures of the article, or could be accurately extrapolated from the data presented. If no data were reported for a particular outcome, in particular adverse outcomes, then no value was tabulated. This was done to avoid the bias caused by incorrectly assigning a value of zero to an outcome measurement on the basis of an unverified assumption by the reviewer. For example, if no mortality rate was reported the result was not assumed to be zero. Data Analysis The included studies were categorised into type of bioengineered skin substitute, then by management of donor sites and management of burns, and by age (paediatric or adult). The data for the main outcomes were not suitable for statistical pooling or meta-analyses and were therefore reported narratively. SECTION 2 z METHODS 17 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - 3. Studies Included in the Review Designation of Levels of Evidence and Critical Appraisal The evidence presented in the included studies was classified according to the National Health and Medical Research Council (NHMRC) Hierarchy of Evidence (See Appendix A). Study quality was assessed according to the methods given in Section 6 of the Cochrane Reviewers’ Handbook (Higgins and Green 2005) on a number of parameters such as the quality of the reporting of study methodology, methods of randomisation and allocation concealment, blinding of patients or outcomes assessors, attempts made to minimise bias, sample sizes and their ability to measure ‘true effect’, applicability of results outside of the study sample as well as examining the statistical methods used to describe and evaluate the study data. The included studies are shown in Table 3, and the study profiles are given in Appendix C. Several authors and/or centres have published numerous reports on their experience with bioengineered skin substitutes. As a result, there are some studies published by the same group where there are very likely to be common pools of patients and such studies will be identified. Description of studies A total of 20 randomised controlled trials were included in this review. The bioengineered skin substitutes from the included studies have been categorised in this review by type, as each are comprised of different components, have different functions and are used at different time points in the various clinical treatment pathways for burns (see Table 3). Thus it would have been inappropriate to combine the results of different products when discussing the outcomes. In some of the studies, the use of the bioengineered skin substitute may be used at a different stage in the clinical treatment pathway to the comparator product, and both may differ in their components and function, which would affect the validity of the comparison. Where appropriate, such studies will be identified and these issues discussed. SECTION 3 z INCLUDED STUDIES 19 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Table 3. Summary of included randomised controlled trials* Study Type of burn Intervention N patients Type of patients Follow-up (days) Partial thickness Biobrane 41 Paediatric NR Silver sulfadiazine 48 Partial thickness Biobrane 10 Paediatric 16 Silver sulfadiazine 10 Partial thickness Biobrane 20 wounds Paediatric ~11 TransCyte 17 wounds Silver sulfadiazine 21 wounds Partial thickness Biobrane 26 (30 wounds) 308 (44 weeks) Silver sulfadiazine 26 (26 wounds) Paediatric & adult Superficial and mid-dermal thickness Biobrane 35 Paediatric ~17 Duoderm 37 Partial thickness Biobrane 82† Paediatric & adult 168 (24 weeks) Partial and full thickness Biobrane 10† Adult 23 14† Paediatric & adult 365 (12 months) NR ~18 NR ~19 BIOBRANE For the management of burns Lal 2000 Barret 2000 Kumar 2004 Gerding 1990 Cassidy 2005 For the management of donor sites Still 2003 Fratianne 1993 OrCel Allogeneic cultured keratinocyte sheets TRANSCYTE For the management of burns Noordenbos 1999 Partial thickness TransCyte Demling & DeSanti 1999‡ Partial thickness (facial) TransCyte 10 Bacitracin ointment 11 Demling & DeSanti 2002†‡ Partial thickness (facial) TransCyte 16 Antibiotic ointments & creams§ 18 10† Paediatric & adult 14 66† Paediatric & adult 28 Silver sulfadiazine DERMAGRAFT For the management of burns Hansbrough 1997‡ Partial and full thickness Dermagraft Purdue 1997‡ Full thickness Dermagraft Allograft Allograft Table continued over … 20 SECTION 3 z INCLUDED STUDIES - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Table 3. Summary of included randomised controlled trials* Study Type of burn Intervention N patients Type of patients Follow-up (days) Spielvogel 1997 Full thickness Dermagraft 65† NR 14 149† Paediatric & adult 365 (1 year) 7† Adult Up to 150 (5 months) 40† Paediatric & adult 730 (2 years) 17† (34 wounds) Paediatric & adult Up to 365 (1 year) 45† (90 wounds) Paediatric Up to 365 (1 year) 15† (16 wounds) Adult 365 (1 year) 15† Paediatric & adult 240-690 (8-23 months) Allograft INTEGRA For the management of burns Heimbach 1988 NR Artificial dermis Auto-, allo- or xenograft Peck 2002 Partial and full thickness Integra Biobrane Allograft APLIGRAF For the management of burns Waymack 2000 Partial and full thickness Apligraf + autograft Autograft AUTOLOGOUS CULTURED SKIN For the management of burns Full thickness Boyce 1995‡ Autologous epidermal substitute Autograft Full thickness Boyce 2002‡ Autologous epidermal substitute Autograft ALLOGENEIC CULTURED SKIN For the management of donor sites Madden 1996 Partial and full thickness Cultured epidermal allograft + Adaptic Adaptic dressing Duinslaeger 1997 NR Allogeneic cultured keratinocyte sheets OpSite dressing NR – not reported; * all included studies are level II, except for Boyce 2002 which is level III-1; † each patient served as their own control (within-patient comparison); ‡ possibly some patient overlap; § particular antibiotic ointments and creams used not specified. Biobrane® for the management of burns Five studies reported on the use of Biobrane® for the management of burns; three comparing Biobrane® with silver sulfadiazine, one comparing Biobrane® with TransCyte® or silver sulfadiazine, and one comparing Biobrane® with Duoderm®. The reporting of methodological detail was generally inadequate in four of the five studies. However, Gerding et al. (1990) reported adequate methodological detail. SECTION 3 z INCLUDED STUDIES 21 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Three of the five studies provided some description of randomisation. The randomisation of patients was done by computer-generated codes or table in two studies (Gerding et al. 1990; Lal et al. 2000) and Kumar et al. (2004) randomised wounds by lottery. Gerding et al. (1990) was the only study that provided a description of their method of allocation concealment, which was by the use of sealed envelopes. The remaining studies did not state their methods of allocation concealment. Four of the five studies reported no blinding of patients or assessors (Barret et al. 2000a; Gerding et al. 1990; Kumar et al. 2004; Lal et al. 2000). Cassidy et al. (2005) did not provide any information on blinding status. All five studies with a parallel design performed appropriate statistical analyses (Barret et al. 2000a; Cassidy et al. 2005; Gerding et al. 1990; Kumar et al. 2004; Lal et al. 2000). Barret et al. (2000a) and Cassidy et al. (2005) performed power analyses to calculate the required sample sizes. However, Lal et al. (2000) reported a lack of statistical power to determine an increase in infectious complications with Biobrane®. Losses to follow-up were reported in two studies (Table 4). The remaining three studies retained all their patients (Barret et al. 2000a; Cassidy et al. 2005; Kumar et al. 2004). Table 4. Losses to follow-up in Biobrane® for burn management studies Study Follow-up (days) Losses to follow-up Reasons Lal 2000 NR Biobrane 7/41 (17%) NR Silver sulfadiazine 3/48 (6%) NR Biobrane 7/64 (11%) Lost to follow-up (2) Gerding 1990 308 (44 weeks) Removed due to protocol violations by non-investigators (4) Excluded due to scarlet fever (1) Silver sulfadiazine 5/64 (8%) Lost to follow-up (4) Removed due to protocol violations by non-investigators (1) NR – not reported. In regards to sources of funding, two of the five studies received independent funding (Cassidy et al. 2005; Lal et al. 2000) and no details were given for the remaining three studies (Barret et al. 2000a; Gerding et al. 1990; Kumar et al. 2004). Biobrane® for the management of donor sites Two studies compared Biobrane® with two different comparators for the management of donor sites in burns patients. The comparators were OrCel™ and allogeneic cultured keratinocyte sheets. The reporting of methodological detail in the two studies was generally good but some information was not provided. Still et al. (2003) reported use of a computer-generated schedule to randomise wounds to receive treatment with either Orcel™ or Biobrane®. Fratianne et al. (1993) did not state their method of treatment allocation. Both studies did not state 22 SECTION 3 z INCLUDED STUDIES - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - their methods of allocation concealment. With regard to blinding status, three independent burn experts assessed wound closure in the study by Still et al. (2003). Fratianne et al. (1993) reported no blinding. Statistical dependence (for comparison of two wounds in the same individual) was accounted for in one study (Still et al. 2003). Fratianne et al. (1993) did not perform any statistical analyses. Still et al. (2003) also used intention-to-treat (ITT) analysis for efficacy, where all patients underwent randomisation of donor sites and received treatment regardless of completion of study, and for safety, where a subset of the ITT population received treatment with a study device regardless of completion of study. Both studies reported losses to follow-up (see Mortality section) (Fratianne et al. 1993; Still et al. 2003). The study by Still et al. (2003) was funded by OrCel™ International, Inc., the manufacturer of the material and Fratianne et al. (1993) did not report their funding source. A study by Prasad et al. (1987) comparing Biobrane® with scarlet red was identified during the search for included studies. However, this study was excluded, as scarlet red is no longer used to manage burn wounds due to its association with sarcoma development in rats (Takeuchi et al. 1975). TransCyte® for the management of burns Three studies reported on the use of TransCyte® for the management of burns; one comparing TransCyte® with silver sulfadiazine and two comparing TransCyte® with antibiotic ointments and creams. The reporting of methodological detail in the three studies was inadequate. All three studies did not provide information on the methods of patient allocation or the methods of allocation concealment. One study reported no blinding of patients or assessors (Noordenbos et al. 1999) and the other two did not provide information on the blinding status (Demling and DeSanti 1999; Demling and DeSanti 2002). Statistical dependence was accounted for in the one within-patient comparison (Noordenbos et al. 1999) and appropriate statistical analyses were performed in one of the parallel design studies (Demling and DeSanti 2002). Demling and DeSanti (Demling and DeSanti 1999) did not provide information on the statistical analyses performed. One study reported losses to follow-up with 3/14 (21%) patients lost to follow-up at three and 12 months and 5/14 (36%) patients lost to follow-up at six months (Noordenbos et al. 1999). The other two studies retained all their patients (Demling and DeSanti 1999; Demling and DeSanti 2002). Demling and DeSanti (Demling and DeSanti 1999) received independent funding for their study. Demling and DeSanti (Demling and DeSanti 2002) and Noordenbos et al. (1999) did not report their funding sources. SECTION 3 z INCLUDED STUDIES 23 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Dermagraft® for the management of burns Three studies compared Dermagraft® with allograft for the management of burns. The comparability of these two products is questionable, as Dermagraft® can be permanently integrated, whereas allograft is a temporary biological dressing. The reporting of methodological detail in the three studies was inadequate. All three studies did not provide information on the methods of patient allocation and the methods of allocation concealment. Two of the three studies provided some information on the blinding status; Purdue et al. (1997) blinded the assessor who analysed the wound biopsies and in Spielvogel (1997), the reviewer was blinded regarding the clinical results. Hansbrough et al. (1997) did not provide information on blinding status. All three studies had within-patient comparisons; two accounted for this statistical dependence (Hansbrough et al. 1997; Purdue et al. 1997). Spielvogel (1997) used within-patient comparisons but did not perform any statistical analyses due to a very small sample size. Two of the three studies reported losses to follow-up (Hansbrough et al. 1997; Purdue et al. 1997) (Table 5). Spielvogel (1997) retained all their patients. Table 5. Losses to follow-up in Dermagraft® for burn management studies Study Follow-up (days) Losses to follow-up* Reasons Hansbrough 1997 14 3/10 (30%) NR Purdue 1997 28 20/66 (30%) Had treatment other than skin grafts (2) Had temporary covering deviations (7) Had premature removal of temporary coverings or autograft (3) Death (8) *only overall data was provided; NR – not reported. The studies by Hansbrough et al. (1997) and Purdue et al. (1997) were funded by Advanced Tissue Sciences, Inc., the manufacturer of Dermagraft®. Spielvogel (Spielvogel 1997) did not report their funding source. Integra® for the management of burns Two studies reported on the use of Integra® (also known as artificial dermis) for the management of burns; one comparing Integra® with autograft, allograft or xenograft and the other comparing it with Biobrane® or allograft. The comparability of Integra® with the other types of burn management is questionable. Integra® is a permanent, integrable dermal substitute and has been compared with a temporary, non-integrable epidermal substitute (Biobrane®) and temporary, biological skin replacements (allograft and xenograft). In addition, Peck et al. (2002) included both partial and full thickness burns in a trial of only seven patients, so the heterogeneity of these groups render it difficult to make valid conclusions. Autograft and Dermagraft® would allow valid comparisons in all of these groups for Integra®, as they are both capable of permanent integration. 24 SECTION 3 z INCLUDED STUDIES - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - The reporting of methodological detail in the two studies was inadequate. Both studies did not provide information on the methods of patient allocation and the methods of allocation concealment. Both studies did not provide information on blinding status (Heimbach et al. 1988; Peck et al. 2002). Statistical dependence was accounted for in the within-patient comparison by Heimbach et al. (1988). Peck et al. (2002) used within-patient comparisons but did not perform any statistical analyses due to a very small sample size. The trial by Peck et al. (2002) was stopped early due to a high infection rate. Both studies reported losses to follow-up (Heimbach et al. 1988; Peck et al. 2002) (Table 6). Table 6. Losses to follow-up in Integra® for burn management studies Study Follow-up (days) Losses to follow-up* Reasons Peck 2002 Up to 150 (5 months) 4/7 (57%) Patient moved interstate after discharge (1) Death (3) Heimbach 1988 365 (1 year) 67/149 (45%) Eliminated from analysis due to protocol violation (37) Eliminated from analysis due to logistic reasons or longterm assessment was not possible (10) Death (20) *only overall data was provided. Marion Laboratories (Kansas City, MO, USA) partly funded the study by Heimbach et al. (1988) and provided in-house statisticians to perform the statistical analyses. Peck et al. (2002) received independent funding for their study. Apligraf® for the management of burns One study reported on the use of Apligraf® combined with autograft compared with autograft only for the management of burns. The methodological detail reported in this study was inadequate. No information on the method of patient allocation, the method of allocation concealment and blinding status was provided. Statistical dependence was accounted for in this within-patient comparison (Waymack et al. 2000). The authors used last observation carried forward (LOCF) analysis, where data from the prior evaluation point was carried forward to estimate missing patient information. Losses to follow-up were reported in Waymack et al. (2000) (Table 7). SECTION 3 z INCLUDED STUDIES 25 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Table 7. Losses to follow-up in Apligraf® for burn management studies Study Follow-up (days) Losses to follow-up* Waymack 2000 730 (2 years) 24/40 (60%) Reasons Lost to follow-up (20) Excluded due to non-compliance (2) Due to Apligraf loss (1) Data not collected after grafting (1) *only overall data was provided. Two of the investigators on the Waymack et al. (2000) trial were full-time employees of Organogenesis Inc., the manufacturer of Apligraf®. Autologous cultured skin for the management of burns Two studies reported on the use of an autologous epidermal substitute compared with autograft only for the management of burns. The comparability of these two types of management is questionable, as autograft is comprised of both dermis and epidermis and would have a different function to just a cultured epidermis. Ideally, both groups should be comprised of a dermis and epidermis to enable valid comparisons. The reporting of methodological detail in the two studies was generally good but some information was not provided. Both studies reported randomisation methods; one study randomised wounds using a computer-generated schedule (Boyce et al. 1995) and another was a pseudorandomised controlled trial, where wounds were randomised according to patient enrolment number (Boyce et al. 2002). However, information on their methods of allocation concealment was not provided. Both studies reported no blinding of patients or assessors (Boyce et al. 1995; Boyce et al. 2002). Both studies were within-patient comparisons and accounted for this statistical dependence (Boyce et al. 1995; Boyce et al. 2002). One of the two studies reported losses to follow-up (13/17 (76%) patients at one year) (Boyce et al. 1995). The other study by Boyce et al. (2002) retained all their patients. Both studies received funding from independent sources. Allogeneic cultured skin for the management of donor sites Two studies reported on the use of allogeneic cultured skin for the management of donor sites; one study compared cultured epidermal allograft combined with Adaptic™ dressing and Adaptic™ dressing alone, and the other study compared allogeneic cultured keratinocyte sheets and OpSite® dressing alone. The methodological detail reported in the two studies was inadequate. Both studies did not state the methods of treatment allocation and the methods of allocation concealment (Duinslaeger et al. 1997; Madden et al. 1996). Whether selection bias and reporting bias occurred in these studies could not be determined 26 SECTION 3 z INCLUDED STUDIES - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - due to the lack of detail on the method of treatment allocation and allocation concealment. In both studies, the assessor was blinded (Duinslaeger et al. 1997; Madden et al. 1996)); Madden et al. (1996) stated that the trial was double-blinded but only mentioned blinding of the assessor. The two studies did not account for the lack of statistical independence; Madden et al. (1996) reported the use of a signed rank test for comparisons of reepithelialisation, and Duinslaeger et al. (1997) did not provide any information on the statistical tests performed. The lack of statistical analyses may have been due to the small sample sizes, which would decrease the power of the study to detect any differences. Patients were lost to follow-up in Madden et al. (1996) (3/16, 19%) and Duinslaeger et al. (1997) retained all their patients. Madden et al. (1996) stated no financial ties and Duinslaeger et al. (1997) did not report their funding sources. SECTION 3 z INCLUDED STUDIES 27 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - 4. Results Efficacy Biobrane® Biobrane® is a biosynthetic dressing composed of a knitted nylon mesh that is bonded to a thin, silicone membrane and coated with porcine polypeptides (Hansen et al. 2001). It can be used as a temporary covering for clean, debrided superficial and mid-dermal burns and donor sites or as a protective covering over meshed autografts. Biobrane® is designed to adhere to the burn wound and is trimmed away as the burn wound heals (Hansen et al. 2001). For the management of burns Three studies compared Biobrane® with silver sulfadiazine (Barret 2000a; Gerding 1990; Lal 2000), one study compared Biobrane® and TransCyte® with silver sulfadiazine (Kumar 2004) and another study compared Biobrane® with Duoderm® (Cassidy 2005). All five studies had parallel comparisons. Follow-up times ranged from 11 days to 44 weeks. Mean total burn surface area (TBSA) and mechanism of burn injury are detailed in Appendix D. The mean TBSA varied across the studies but did not appear to influence the outcomes reported. Wound infection Two studies reported on wound infection (Barret 2000a; Gerding 1990). Gerding (Gerding 1990) reported similar numbers of cases of wound infection from both groups (3/30 wounds (10%) treated with Biobrane® and 2/26 wounds (8%) treated with silver sulfadiazine). None of the patients receiving Biobrane® or silver sulfadiazine in the Barret (Barret 2000a) study had wound infection. Kumar (Kumar 2004), Lal (Lal 2000) and Cassidy (Cassidy 2005) did not provide information on wound infection. Wound healing time Wound healing time was measured by number of days to healing (Barret 2000a; Cassidy 2005; Gerding 1990; Kumar 2004) or days per percent TBSA burned (Lal 2000). Four studies reported a significantly shorter wound healing time with the use of Biobrane® compared with silver sulfadiazine (Table 8). Gerding (Gerding 1990) noted that in their sample, the greatest difference in healing time was observed in grease/tar burns (8.4 [3.0] days (n=9 wounds) for Biobrane® vs. 18.5 [10.0] days (n=4 wounds) for silver sulfadiazine, p<0.02), there was an average 4.4-day difference in the healing of scald burns (but the difference was not significant due to the small sample size for this sub-group) and no difference was observed in the 28 SECTION 4 z RESULTS - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - healing time for contact burns. Kumar (Kumar 2004) reported the shortest wound healing time in paediatric patients with wounds treated with TransCyte®. There was no significant difference in wound healing time between Biobrane® and Duoderm® (Table 8) (Cassidy 2005). Table 8. Wound healing time for burns managed with Biobrane® and comparators Study Biobrane TransCyte Silver sulfadiazine Duoderm P-value Kumar 2004 9.5 (20) 7.5 (17) 11.2 (21) … <0.001* Gerding 1990 10.6 [4.1] (26) … 15.0 [6.1] (26) … <0.01 Barret 2000 9.7 [2.2] (10) … 16.1 [1.9] (10) … <0.001 Cassidy 2005 12.24 [5.1] (35) … … 11.21 [6.5] (37) 0.47 … <3 yrs: 2.35 [1.35] (31) … 0.025 Number of days Days / % TBSA burned Lal 1999 <3 yrs: 1.52 [2.45] (26) 3-17 yrs: 1.00 [0.51] (8) 3-17 yrs: 2.40 [0.75] (14) 0.026 * P-value across all three groups. Ellipses indicate not applicable. Values expressed as Mean [Standard Deviation] (sample size) unless stated otherwise. Wound closure Significantly more partial thickness burns sites treated with silver sulfadiazine appeared to require skin grafting to close the wound than sites covered with TransCyte® or Biobrane® (Kumar 2004) (Table 9). Kumar (Kumar 2004) reported that wounds in the Biobrane® group (n=3) and TransCyte® group (n=1) required autografting due to infection and loss of product, and wounds in the silver sulfadiazine group (n=5) underwent grafting due to delayed re-epithelialisation. One wound from each group required skin grafting in the Gerding (Gerding 1990) study. Cassidy (Cassidy 2005) did not provide information on wound closure. Table 9. Number of wounds requiring skin grafting to close the wound Study Biobrane TransCyte Silver sulfadiazine P-value Kumar 2004 3/17 wounds (18%) 1/20 wounds (5%) 5/21 wounds (24%) <0.001* Gerding 1990 1/30 wounds (3%) … 1/26 wounds (4%) NP * P-value across all three groups; NP – statistical analysis not performed. Ellipses indicate not applicable. Patient-related outcomes Pain was assessed using scales of different magnitudes (Table 10). Significantly more pain was reported from sites treated with silver sulfadiazine than sites covered with Biobrane® in two studies (Barret 2000a; Gerding 1990). There was no significant difference in pain scores for Biobrane® and Duoderm®. SECTION 4 z RESULTS 29 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Table 10. Wound pain scores for burns managed with Biobrane® and comparators Study Biobrane Silver sulfadiazine Duoderm P-value Visual analogue scale and Faces scale (0, none to 4, severe) Barret 2000 … Admission 3.3 [0.3] (10) 3.8 [0.6] (10) PNS Day 1 2.4 [0.3] (10) 3.7 [1.3] (10) <0.001 Day 2 2.6 [0.9] (10) 3.8 [1.3] (10) <0.001 1.6 [4.1] (26) 3.6 [6.6] (26) Score (1, none to 5, severe) Gerding 1990 … <0.001 2.37 [2.77] 0.993 Oucher scale (n=34) and Visual analogue scale (n=37)* Cassidy 2005 2.36 [2.62] … * reported as a mean aggregate score; PNS – p-value not significant. Ellipses indicate not applicable. Values expressed as Mean [Standard Deviation] (sample size) unless stated otherwise. Patients who received Biobrane® also required significantly less pain medication than those receiving silver sulfadiazine treatment in two studies: 0.6 [7.1] tablets vs. 3.0 [17.8] tablets (p<0.01) (Gerding 1990) and 0.5 [0.3] doses/person/day vs. 1.9 [1.3] doses/person/day (p<0.001) (Barret 2000a). Kumar (Kumar 2004) also reported that patients who received Biobrane® or TransCyte® required significantly fewer pain medications (narcotic analgesia) than those treated with silver sulfadiazine (p=0.0001). In regards to dressing changes, sites treated with silver sulfadiazine required a significantly higher number of dressing changes (mean 9.2 dressing changes per wound) than Biobrane® (mean 2.4 dressing changes per wound) and TransCyte® (mean 1.5 dressing changes per wound) (Kumar 2004) (p=0.0001). For the management of donor sites Biobrane® was compared with two different products in two different studies. One study compared Biobrane® with OrCel™ (Still 2003) and another with allogeneic cultured keratinocyte sheets (Fratianne 1993). All three studies had within-patient comparisons. Follow-up times were 23 days (Fratianne 1993) and 24 weeks (Still 2003). Mean TBSA and mechanism of burn injury are detailed in Appendix D. The mean TBSA was comparable across the two studies. Wound infection No statistically significant differences were noted between sites covered with Biobrane® and OrCel™ (Still 2003). Fratianne (Fratianne 1993) did not provide any information on wound infection. Wound healing time The wound healing time for donor sites covered with Biobrane® was significantly longer than for sites treated allogeneic cultured keratinocytes (Table 11) (Fratianne 1993). 30 SECTION 4 z RESULTS - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Table 11. Wound healing time (days) for donor sites managed with Biobrane® and comparators: part 1 Study Biobrane Allogeneic cultured keratinocyte sheets P-value Fratianne 1993 Median 14 (n=10) Median 6 (n=10) <0.005 (range 7-23) (range 5-11) Still (Still 2003) measured time to 100% wound closure using investigator, planimetric and photographic assessments, and also reported significantly longer wound healing times for sites covered with Biobrane® compared with those covered with OrCel™ (Table 12). Table 12. Wound healing time (days) for donor sites managed with Biobrane® and comparators: part 2 Study Biobrane OrCel P-value Mean Median Mean Median Mean / Median Investigator assessment 18.4 16.0 13.2 12.0 <0.0001 / <0.0001 Planimetric assessment 19.3 17.0 13.7 12.0 <0.0001 / <0.0001 Photographic assessment 22.4 22.0 18.0 15.0 <0.0001 / <0.0006 Still 2003 The median time required for the donor site to be ready for recropping was seven days less for OrCel™ than the median time for Biobrane® (the mean time for OrCel™ was five days less than the mean for Biobrane®) (Still 2003). The absolute values were not provided. Wound closure Two studies reported wound closure (Fratianne 1993; Still 2003). Still (Still 2003) reported significant differences in the rates of wound closure per day (by planimetric assessments) during the 32-day post-surgical period in the ITT population (p<0.05). The mean rate of wound closure for OrCel™ on days 6 through 16 was 61% faster than Biobrane® (6.1 vs. 3.8cm2 per day, respectively), and on days 17 to 32 OrCel™ was 90% faster than Biobrane® (4.0 vs. 2.1cm2 per day, respectively) (Still 2003). The percentage of donor sites covered with OrCel™ that completely healed by day 32 was significantly higher than donor sites covered with Biobrane® for all assessment methods (Table 13). Table 13. Percentages of sites completely healed by Day 32 Study OrCel Biobrane P-value Investigator assessment 79 / 82 (96.3%) 71 / 82 (86.6%) <0.0047 Planimetric assessment 76 / 82 (92.7%) 66 / 82 (80.5%) <0.0039 Photographic assessment 70 / 82 (85.4%) 50 / 82 (61.0%) <0.001 Still 2003 SECTION 4 z RESULTS 31 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - In 3/10 (30%) patients, the donor sites covered with allogeneic cultured keratinocyte sheets had re-epithelialised and were reharvested (Fratianne 1993). No Biobrane® sites were reharvested. Wound exudate No studies reported on wound exudate. Patient-related outcomes Still (Still 2003) assessed pain at the donor site for three different age groups: 0 to 10 scale (0 indicating no pain and 10 indicating worst pain possible) was used to rate pain in patients eight years of age or older; the Wong-Baker Faces Pain Rating Scale was used with patients aged three to seven; and objective measurements were used for patients less than three years of age. The mean daily pain score was 1.4 for donor sites covered with OrCel™ and 1.8 for donor sites covered with Biobrane® across all three groups (i.e. less pain for OrCel™ group). Scar severity was measured using two methods; the Vancouver Scar Scale and the Hamilton Burn-Scar Rating Scale (Still 2003). For both methods, the total scores for sites covered with OrCel™ were significantly lower (i.e. less scarring) than for sites covered with Biobrane® at weeks 12 and 24 (Table 14). No statistically significant difference between the sites was observed using the Vancouver Scar Scale at the biannual follow-up visit. The severity and incidence of donor site itching was similar for sites covered with OrCel™ or Biobrane® (72.2% and 68.8%, respectively) (Still 2003). Table 14. Scar severity (mean scores) for Biobrane® versus OrCel™ Study Biobrane OrCel P-value Vancouver Hamilton Vancouver Hamilton Vancouver / Hamilton Week 12 3.07 4.95 2.26 3.89 <0.017 / 0.018 Week 24 3.79 3.5 2.56 2.46 <0.002 / 0.020 Biannual 3.95 NR 3.10 NR PNS / NR Still 2003 NR – not reported; PNS – p-value not significant. TransCyte® TransCyte® is a temporary, biosynthetic covering composed of a semi-permeable silicone membrane and newborn human fibroblast cells cultured on a porcine collagen coated nylon mesh (Hansen et al. 2001). It has been indicated for use as a temporary covering for excised burns prior to autografting or burns that do not require autografting (partial thickness burns) and its physical properties (pliability) allow it to easily conform to the contours of the face (Hansen et al. 2001). TransCyte® is applied to the burn using adhesive strips or surgical adhesives and will peel away as the burn heals. 32 SECTION 4 z RESULTS - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - For the management of burns TransCyte® was compared with silver sulfadiazine in one study (within-patient comparison) (Noordenbos 1999) and antibiotic ointments and creams in two studies (both had parallel comparisons) (Demling and DeSanti 1999; Demling and DeSanti 2002). Follow-up times ranged from 18 days to 12 months. Mean TBSA and mechanism of burn injury are detailed in Appendix D. The mean TBSA did not appear to influence the outcomes reported. Wound infection All three studies reported on wound infection (Table 15). Noordenbos (Noordenbos 1999) reported no cases of wound infection during treatment with TransCyte® and mild cellulitis in six patients during silver sulfadiazine treatment, which responded to intravenous antibiotics. No wound infections were reported for partial thickness facial burns treated with TransCyte® or topical antibiotics in two studies (Demling and DeSanti 1999; Demling and DeSanti 2002). Table 15. Wound infection for burns managed with TransCyte® and comparators Study TransCyte Silver sulfadiazine Topical antibiotics Noordenbos 1999 0/14 patients 6/14 patients (43%) … Demling & DeSanti 1999* 0/5 patients … 0/6 patients Demlind & DeSanti 2002 0/16 patients … 0/18 patients *for major burns only (patients were split into major and minor burns). Ellipses indicate not applicable. Wound healing time Wound healing time was reported in three different ways across the three studies (Table 16). However, all the studies reported a shorter wound healing time for sites covered with TransCyte®. Table 16. Wound healing time for burns managed with TransCyte® and comparators Study TransCyte Silver sulfadiazine Topical antibiotics P-value Major: 8 [2] (5) … Major: 14 [4] (6) <0.05 Minor: 12 [3] (5) <0.05 18.14 [6.05] (14) … NS … 15 [4] (18) <0.05 Number of days Demling & DeSanti 1999 Minor: 8 [1] (5) Days until 90% healing Noordenbos 1999 11.14 [4.37] (14) Days to 95% re-epithelialisation Demling & DeSanti 2002 9 [4] (16) NS – not stated. Ellipses indicate not applicable. Values expressed as Mean [Standard Deviation] (sample size) unless stated otherwise. Wound closure No skin grafts were required for sites covered with TransCyte® in two studies (Demling and DeSanti 1999; Noordenbos 1999) and 2/14 (14%) patients in the silver SECTION 4 z RESULTS 33 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - sulfadiazine arm required skin grafting to close the wound (Noordenbos 1999). No data was provided for sites treated with topical antibiotics (Demling and DeSanti 1999). For partial thickness facial burns, it was reported that the use of TransCyte® had good adherence to the entire face including ears and there was no need for reapplication (Demling and DeSanti 1999). Patient-related outcomes Wound care time was reported in patients with major and minor burns to the face in Demling and DeSanti (Demling and DeSanti 1999). The major and minor burns covered with TransCyte® had significantly shorter wound care time than those treated with topical antibiotics (major burns, 0.35 [0.5] hours/day vs. 1.9 [0.5] hours/day; minor burns, 0.4 [0.1] hours/day vs. 2.2 [0.4] hours/day, p<0.05, respectively). The patients in the two studies by Demling & DeSanti (Demling and DeSanti 1999; Demling and DeSanti 2002) reported significantly more pain during and between dressing changes for sites treated with topical antibiotics than sites covered with TransCyte® (Table 17). Table 17. Wound pain scores for burns managed with TransCyte® and topical antibiotics Study TransCyte Topical antibiotics P-value 2 [1] (5) / 2 [1] (5) 5 [1] (6) / 5 [1] (5) <0.05 / <0.05 2 [1] (5) / 1 [0.5] (5) 4 [2] (6) / 3 [2] (5) <0.05 / <0.05 During dressing changes 3 [1] (16) 7 [2] (18) <0.05 Between dressing changes 2 [1] (16) 4 [2] (18) <0.05 Visual analogue scale (0, lowest to 10, highest) Demling & DeSanti 1999 During dressing changes (major burns / minor burns) Between dressing changes (major burns / minor burns) Demling & DeSanti 2002 Values expressed as Mean [Standard Deviation] (sample size) unless stated otherwise. Scar severity was measured in one study using the Vancouver Burn Scar Score (where lower ratings indicate more normal skin appearance) (Noordenbos 1999). At all follow-up time points, the sites covered with TransCyte® had significantly less scarring than sites treated with silver sulfadiazine; 1.39 [1.14] vs. 4.82 [1.27] (p<0.001, n=11) at three months, 0.8 [1.312] vs. 3.7 [1.373] (p<0.001, n=9) at six months, and 0.375 [0.744] vs. 2.125 [1.458] (p=0.006, n=11) at 12 months. Dermagraft® Dermagraft® is a bioabsorbable polyglactin mesh seeded with allogeneic neonatal fibroblasts (Hansen et al. 2001). The fibroblasts proliferate and produce dermal collagen, growth factors, glycosaminoglycans (GAGs) and fibronectin and the mesh material is gradually absorbed (Hansen et al. 2001). It can be used as a temporary or permanent covering to support the take of meshed split-thickness skin grafts on 34 SECTION 4 z RESULTS - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - excised burn wounds (Hansbrough 1997) and for venous ulcers and pressure ulcers (Hansen et al. 2001). For the management of burns Three studies compared Dermagraft® with allograft (Hansbrough 1997; Purdue 1997; Spielvogel 1997) and all had within-patient comparisons. Follow-up times ranged from 14 to 28 days. Mean TBSA and mechanism of burn injury are detailed in Appendix D. The mean TBSA was greater in Purdue (Purdue 1997) than Hansbrough (Hansbrough 1997). Wound infection Two studies reported on wound infection (Purdue 1997; Spielvogel 1997). No significant differences were detected between the use of Dermagraft® and allograft for full thickness burns in two studies (Purdue 1997; Spielvogel 1997). However, Purdue (Purdue 1997) noted that infection was diagnosed in 5/66 (8%) wounds, a mean 3.8 days (range 1-7) earlier for the Dermagraft® covered wound than for the paired allograft covered wound, and in no case was an allograft covered wound infection diagnosed before a Dermagraft® covered wound infection. Wound healing time Only one study reported wound healing time (Hansbrough 1997). Hansbrough (Hansbrough 1997) compared Dermagraft® red (cultured fibroblasts were cryopreserved by a method that maintains most of the metabolic activity), Dermagraft® blue (cultured fibroblasts were frozen by a method that did not maintain metabolic activity), and allograft. They reported no significant differences between treatments and all partial and full thickness burns were completely healed by day 21. Wound closure Granulation tissue formation was measured in two studies (Purdue 1997; Spielvogel 1997). Of the full thickness burns covered with allograft, 74% had granulation tissue present compared with 51% in wounds covered with Dermagraft® (Purdue 1997). A histologic study by Spielvogel (Spielvogel 1997) reported similar results with 78% (40/51) of allograft treated full thickness burns and 51% (26/51) of Dermagraft® treated burns having granulation tissue present. In regards to graft take, allograft and Dermagraft® produced comparable results (Hansbrough 1997; Purdue 1997) (Table 18). SECTION 4 z RESULTS 35 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Table 18. Percent graft take for burns managed with Dermagraft® and allograft Study Dermagraft Hansbrough 1997 Allograft P-value Red Blue Day 5 (n=8) 93.8 [10.26] 98.8 [2.31] 98.8 [10.26] 0.19* Day 9 (n=7) 97.1 [7.56] 99.3 [1.89] 97.9 [2.67] 0.72* 100 [0] 97.9 [3.93] 96.4 [3.78] 0.0527* 93.1 0.0001 Day 14 (n=7) Purdue 1997 (n=46) 94.7 * across all three groups. Values expressed as Mean [Standard Deviation] unless stated otherwise. Wound exudate Purdue (Purdue 1997) reported minimal fluid accumulation under both coverings, though it was significantly higher in the Dermagraft® group than the allograft group on days 5, 9, 14, and on the day of removal (p<0.02). The mean fluid accumulation score for the Dermagraft® red group was significantly higher than the scores for the Dermagraft® blue and allograft groups on day 5 only (p=0.0074) (no specific scores were provided) (Hansbrough 1997). Patient-related outcomes Ease of removal was recorded in two studies (Hansbrough 1997; Purdue 1997). Dermagraft® was significantly easier to remove than allograft (p=0.0379), with 1/66 (1.5%) wounds requiring surgical excision of Dermagraft® and 11/66 (17%) wounds requiring surgical excision of allograft (Purdue 1997). Hansbrough (Hansbrough 1997) noted that Dermagraft® blue was easier to remove than Dermagraft® red and allograft. Sloughing was reported in two studies (Hansbrough 1997; Purdue 1997). For Hansbrough (Hansbrough 1997), no sloughing was required for Dermagraft® treated wounds (both blue and red) compared with 4/10 (40%) allograft treated wounds requiring sloughing of the epidermal layer. Purdue (Purdue 1997) reported that the average amount of sloughing was 3.6% at day 5, which increased to 49.9% at day 18, with more than half of the allograft wounds at day 9 and all of the allograft wounds at day 18 exhibiting some epidermal sloughing. In terms of patient satisfaction, the investigators in the study by Purdue (Purdue 1997) reported a significantly higher level of satisfaction with Dermagraft® compared with allograft on the day of removal (p=0.0167). The technique used to measure patient satisfaction was not stated. Integra® Integra® is composed of two layers; a bovine collagen-based dermal analogue, which integrates with the patient’s own cells and a temporary epidermal silicone sheet that is peeled away as the wound heals (Hansen et al. 2001). A very thin autograft is then 36 SECTION 4 z RESULTS - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - grafted onto the neo-dermis. Integra® is indicated for the post-excisional treatment of full thickness or deep partial thickness burns (Hansen et al. 2001). For the management of burns Integra® was compared with autograft, allograft or xenograft (Heimbach 1988) and Biobrane® or allograft (Peck 2002) in two studies. Both studies were within-patient comparisons. Follow-up times ranged from five months to one year. Mean TBSA and mechanism of burn injury are detailed in Appendix D. The mean TBSA was greater in Peck (Peck 2002) than Heimbach (Heimbach 1988). Wound infection In the study by Peck (Peck 2002), four patients had an Integra® covered wound paired with a Biobrane® covered wound and three patients had an Integra® covered wound paired with an allograft covered wound. The allograft covered sites had no signs of infection, two of the four (50%) Biobrane® covered sites developed infections, and all seven sites (100%) covered with Integra® developed infections. Due to the high incidence of infectious complications associated with Integra®, as well as the failure of Integra® to make a significant contribution to wound closure in patients with burns greater than 45% TBSA, the trial was terminated after discussion with the Committee on the Protection of the Rights of Human Subjects. Heimbach (Heimbach 1988) did not report on wound infection. Wound healing time One study reported wound healing time (Heimbach 1988). Sites covered with autograft, allograft or xenograft had a significantly longer wound healing time than sites covered with Integra® (14.3 [6.9] days vs. 10.6 [5.8] days, p<0.001) (Heimbach 1988). Details on the number of patients who received autograft, allograft or xenograft were not reported separately. Wound closure In regards to graft take, biological skin replacements (autograft, allograft, or xenograft) had significantly better take than Integra® (Table 19) (Heimbach 1988). Table 19. Proportion of patients with ≥75% wound closure for Integra® and comparators Study Integra Auto-, allo- or xenograft P-value Heimbach 1988 (n=106) 62 [4] (median 80) All: 79 [3] (median 95) <0.0001 Allograft only*: 66 [8] * sample size not specified. Values expressed as Mean [Standard Deviation] unless stated otherwise. Patient-related outcomes Heimbach (Heimbach 1988) reported patient and physician preferences. The majority of patients (53/82, 64%) and physicians (37/82, 45%) found the Integra® and biological skin replacement (autograft, allograft, or xenograft) sites equivalent. SECTION 4 z RESULTS 37 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Apligraf® Apligraf® is a bilayered living skin equivalent composed of type I bovine collagen and allogeneic keratinocytes and fibroblasts obtained from neonatal foreskin (Hansen et al. 2001). It has to be applied “fresh”, as it has a shelf-life of five days at room temperature (Hansen et al. 2001) and has been used as a temporary covering over meshed expanded autograft for excised burn wounds (Waymack 2000). For the management of burns One study reported the use of Apligraf® with two years’ follow-up (Waymack 2000). This study was a within-patient comparison with sites covered with either Apligraf® combined with autograft or autograft only. Mean TBSA and mechanism of burn injury are detailed in Appendix D. Wound healing time Waymack (Waymack 2000) reported a median eight days to greater than 75% closure of interstices for Apligraf® and autograft combined compared with a median 13 days for autograft only for the treatment of partial and full thickness burns. Wound closure The use of Apligraf® between the wound surface and the autograft appeared to accelerate the rate of wound closure, with 53% (20/38) of patients having greater than 75% closure compared with 37% (14/38) of patients who received autograft only after the first week (Waymack 2000). By one month the proportion of patients with greater than 75% closure was the same in both groups (Table 20). Table 20. Proportion of patients with ≥75% wound closure for Apligraf® and autograft Study Apligraf + autograft Autograft P-value Week 1 20/38 (53%) 14/38 (37%) NP Week 2 34/38 (89%) 33/38 (87%) NP Month 1 36/38 (95%) 36/38 (95%) NP Waymack 2000 NP – not performed. There was no significant difference in the proportion of patients with greater than 75% graft take between Apligraf® and autograft combined and autograft only (38/38, 100% vs. 37/38, 97%, respectively) (Waymack 2000). Wound exudate No significant differences were detected between autograft and Apligraf® combined with autograft (Waymack 2000). However, wound exudate was reported in fewer wounds treated with Apligraf® and autograft combined than with autograft only (7/38, 18% vs. 10/38, 26%, respectively) (Waymack 2000). 38 SECTION 4 z RESULTS - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Patient-related outcomes Compared with autograft only, the use of Apligraf® combined with autograft resulted in scar tissue that was significantly closer to normal skin, a significantly smoother (closer to normal) surface texture, and a greater proportion of wounds with pigmentation closer to normal, at all follow-up time points (Waymack 2000). The proportion of patients with normal pliability was also significantly greater for Apligraf® combined with autograft than autograft only at all follow-up time points except week 1 (Waymack 2000). Table 21 provides more detail on these outcomes. Table 21. Other patient-related outcomes for Waymack 2000 (n=40) Outcomes Apligraf + autograft Autograft Cosmesis Wk 1 Wk 2 Mth 1 Mth 2 Mth 6 Mth 12 Mth 24 Wk 1 Wk 2 Mth 1 Mth 2 Mth 6 Mth 12 Mth 24 4.81 4.89 4.89 5.26 5.13 4.76 4.89 <0.05 <0.05 <0.001 <0.001 <0.001 <0.001 <0.0001 Vancouver Scar Score (0=normal, 13=abnormal) 4.38 4.32 4.18 4.16 3.79 3.08 2.55 P-value Pigmentation No. of patients with normal pigmentation Mth 6 Mth 12 Mth 24 5/38 (13%) 12/38 (32%) 17/38 (45%) Mth 6 Mth 12 Mth 24 2/38 (5%) 5/38 (13%) 5/38 (13%) PNS Pliability (no. of patients with normal pliability) Wk 1 Mth 1 Mth 6 Mth 24 6/38 (16%) 20/38 (53%) 22/38 (58%) 23/38 (60.5%) Wk 1 Mth 1 Mth 6 Mth 24 1/38 (3%) 7/38 (18%) 5/38 (13%) 5/38 (13%) PNS <0.001 <0.0001 <0.0001 Surface texture Mth 0.5-1 Mth 2 Mth 3-6 Mth 7-12 Mth 13+ 8.3 [1.3] 8.9 [0.6] 8.8 [0.6] 8.5 [1.9] 8.6 [2.5] Mth 0.5-1 Mth 2 Mth 3-6 Mth 7-12 Mth 13+ 7.2 [1.3] 7.0 [1.3] 6.9 [1.9] 7.3 [1.3] 7.7 [1.9] <0.05 <0.05 <0.05 <0.05 <0.05 Score (0=rough, 10=smooth) <0.05 <0.05 PNS – p-value not significant. Autologous cultured skin The preparation of autologous cultured skin involves the collection of biopsy samples from the burns patient as early as possible after injury (Boyce 2002). The keratinocytes and fibroblasts are isolated and grown in serum-free culture media, harvested and prepared for grafting onto full thickness burn sites (Boyce 2002). For the management of burns Two studies with possible patient overlap compared an autologous epidermal substitute with autograft only for full thickness burns (Boyce 1995; Boyce 2002). Both studies had within-patient comparisons with up to one-year follow-up. Mean TBSA and mechanism of burn injury are detailed in Appendix D. The mean TBSA was comparable across the two studies. SECTION 4 z RESULTS 39 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Wound closure There was no significant difference between the two groups in percent reepithelialisation for the first two weeks (Boyce 2002). However, autograft had a higher percent re-epithelialisation and percent TBSA closed in the long-term (after two weeks and up to one year) (Table 22) (Boyce 1995; Boyce 2002). In regards to graft take, autograft had a high percentage and was superior to autologous epidermal substitute (Boyce 1995; Boyce 2002). A higher proportion of patients in the autologous epidermal substitute group required regrafting as opposed to patients in the autograft only group (p<0.05) (Boyce 1995; Boyce 2002). The first eight patients in the Boyce (Boyce 1995) trial whose full thickness burns were covered with autologous epidermal substitute experienced complete or nearly complete failure and required regrafting. However, as experience was gained, graft take improved markedly (Table 22). Table 22. Wound closure, graft take and number of patients requiring skin grafting Study Autologous epidermal substitute Autograft P-value 50-60 (17) >80 (17) <0.05† Day 7 79.9 (45) 85.4 (45) NP Day 14 71.5 (45) 90.8 (45) NP Day 14 15.4 [7.6] (12) 60.0 [5.5] (12) NP Day 28 16.7 [9.0] (12) 58.7 [6.2] (12) NP Day 14 89.2 [8.7] (12) 94.9 [12.5] (12) NP Day 28 95.4 [6.2] (12) 99.0 [2.8] (12) NP 11/17 (65%) 0/17 <0.05 16/45 (36%) 1/45 (2%) <0.05 2/12 (17%)‡ 0/12 NP Percent re-epithelialisation Boyce 1995 Boyce 2002 Percent TBSA closed Boyce 2002* Percent graft take Boyce 2002* Skin grafting required Boyce 1995 Boyce 2002 *in the last 12 patients (total 45 patients); † at days 10, 11 and 14; ‡ regrafting was partial, not total; NP – statistical analysis not performed. Values expressed as Mean [Standard Deviation] (sample size) unless stated otherwise. Wound exudate Although no significant differences were detected between autograft and autologous epidermal substitute, the mean percentage of wounds with exudate was less for autograft only than autologous epidermal substitute at day seven (33% (SE: 51.7) vs. 40 SECTION 4 z RESULTS - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - 44% (SE: 52.3), respectively) and day 14 (18% (SE: 47.6) vs. 41% (SE: 55.7), respectively) (Boyce 2002). Patient-related outcomes Scars from sites covered with autograft were significantly flatter (closer to normal skin) than sites covered with autologous epidermal substitute up to 12 months follow-up, but both sites were similar after 13 months (p<0.05) (Table 23) (Boyce 2002). The scar colour appeared to be better for autograft than autologous epidermal substitute and this was significant at day 14 (p<0.05) (Table 23) (Boyce 2002). Pigmentation scores increased progressively for sites covered with autologous epidermal substitute or autograft (Boyce 2002). There was a significant difference between the two groups, with pigmentation in the autologous epidermal substitute group closer to normal than the autograft group at two to four weeks follow-up (p<0.05) (Table 23). Table 23. Other patient-related outcomes for Boyce 2002 Outcomes Autologous epidermal substitute (n=45) Autograft (n=45) P-value Raised scar Mth 0.5-1 Mth 2 Mth 3-6 Mth 7-12 Mth 13+ 8.7 [1.3] 8.8 [1.3] 8.8 [1.7] 9.2 [0.7] 8.4 [1.3] Mth 0.5-1 Mth 2 Mth 3-6 Mth 7-12 Mth 13+ 8.0 [1.3] 7.5 [2.0] 7.1 [2.0] 7.9 [1.3] 8.4 [2.7] <0.05 <0.05 <0.05 <0.05 PNS Day 7 Day 14 5.43 [1.1] 6.20 [2.0] Day 7 Day 14 6.04 [1.7] 7.75 [1.7] PNS <0.05 Mth 0.5-1 9.5 [1.3] Mth 0.5-1 8.5 [2.0] <0.05 Score (0 = 5mm, 10 = flat) Colour Score (0 = worst, 10 = best) Pigmentation Score* * 0 = hyperpigmentation, 5 = normal pigmentation, 10 = hypopigmentation; PNS – p-value not significant. No significant difference in pliability was reported between autologous epidermal substitute and autograft and both sites were noted to be similar to normal skin (Boyce 2002). Erythema resolved progressively for sites covered with autologous epidermal substitute or autograft with no significant differences between groups (Boyce 2002). Allogeneic cultured skin Allogeneic human epidermal cells are collected and the keratinocytes and/or fibroblasts are isolated and cultured for the preparation of allogeneic cultured skin. Duinslaeger (1997) used cadaveric donor skin to produce cultured sheets (fresh or cryopreserved) which were grafted onto the wound site. Studies assessing allogeneic cultured skin were only available for the management of donor sites. SECTION 4 z RESULTS 41 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - For the management of donor sites Two studies compared an allogeneic cultured skin with a wound dressing (Duinslaeger 1997; Madden 1996). Madden (Madden 1996) compared sites covered with either cultured epidermal allograft combined with Adaptic™ or Adaptic™ dressing alone, with one-year follow-up. Duinslaeger (Duinslaeger 1997) compared allogeneic cultured keratinocyte sheets with OpSite® dressing alone, with 8-23 months follow-up. Both studies were within-patient comparisons. Mean TBSA and mechanism of burn injury are detailed in Appendix D. The mean TBSA was comparable across the two studies. Wound infection One study reported rates of wound infection in which no cases of wound infection were reported from sites treated with allogeneic cultured keratinocyte sheets or sites treated with OpSite® dressings (Duinslaeger 1997). Wound healing time Wounds covered with OpSite® dressing took a significantly longer time to heal than wounds covered with allogeneic cultured keratinocyte sheets (Table 24) (Duinslaeger 1997). No statistical analyses were performed for wound healing time in the Madden (Madden 1996) study; however, the application of a cultured epidermal allograft in between the donor site and Adpatic™ dressing appears to make the wound heal faster (Table 24). Table 24. Wound healing time (mean days) for donor sites managed with an allogeneic cultured skin and comparators Study Bioengineered Skin Substitute Mean [SD] Topical Agent / Wound Dressing Mean [SD] P-value Madden 1996 Cultured epidermal allograft + Adaptic dressing (n=15) 7.8 [2.3] Adaptic dressing (n=15) 9.2 [3.5] NP Duinslaeger 1997 Allogeneic cultured keratinocyte sheets (n=15) 6.7 OpSite dressing (n=15) 13.6 <0.0001 NP - no statistical analyses were performed. Wound closure Both studies reported wound closure (Duinslaeger 1997; Madden 1996). In one study, the percentage of re-epithelialisation (determined by visual estimation) was significantly higher for wounds covered with allogeneic cultured keratinocyte sheets than wounds covered with OpSite® dressing at first inspection (day 4, 5 or 6) and on day 10 (p<0.01) (Table 25) (Duinslaeger 1997). In the other study, wound closure, determined by visual assessment, was assessed in all 13 patients (Madden 1996). Visual examination of the wound margin revealed no differences between sites covered with cultured epidermal allograft and Adaptic™ dressing or Adaptic™ dressing alone (Madden 1996). Biopsies taken from the centre of each wound bed revealed a greater degree of re-epithelialisation (p=0.039) and enhanced epithelial 42 SECTION 4 z RESULTS - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - differentiation (p=0.023) for sites covered with cultured epidermal allograft compared with sites covered with Adaptic™ dressing alone (Madden 1996). Table 25. Percentage of epithelialisation for donor sites managed with allogeneic cultured keratinocyte sheets and OpSite® Study Allogeneic cultured keratinocyte sheet OpSite dressing P-value Day 4, 5 or 6 Mean 93.6 (range 75-100) Mean 54.3 (range 30-70) <0.01 Day 10 Mean 98.6 (range 85-100) Mean 75.6 (range 40-100) <0.01 Duinslaeger 1997 Wound exudate Duinslaeger (Duinslaeger 1997) reported fewer wounds with exudate for sites covered with allogeneic cultured keratinocyte sheets (4/16, 25%), than those covered with OpSite® dressing (11/16, 69%). Madden (Madden 1996) did not provide data on wound exudate. Patient-related outcomes Pain was reported in both studies in different ways. Madden (Madden 1996) reported that pain assessments were equivalent between sites covered with cultured epidermal allograft or Adaptic™ dressing. Duinslaeger (Duinslaeger 1997) used a Visual Analogue Scale (VAS) (range, 0 to 20) to measure pain, where higher scores indicated greater pain. The VAS could not be used in 3/15 (20%) patients due to age and/or general anaesthesia. The mean score for donor sites covered with allogeneic cultured keratinocyte sheets was 10.75 [3.25] (range 5-15) compared with 13.3 [3.1] (range 818) for sites covered with OpSite® dressing (p=0.000029). Cosmetic outcome was also reported in both studies. Mild hypertrophic scarring occurred at one site (1/16, 6.25%) covered with allogeneic cultured keratinocyte sheets and two sites (2/16, 12.5%) covered with OpSite® dressing (Duinslaeger 1997). There were no differences in the quality of the scar after one month, except for mild differences in colour (more redness and hypervascularity) in two sites (2/16, 12.5%) covered with OpSite® dressing (Duinslaeger 1997). Similar results from the Vancouver Scale Scar assessments were reported for sites covered with cultured epidermal allograft or Adaptic™ dressing, where both sites were hypopigmented and either flat or less than 2mm in height up to one year after transplantation (Madden 1996). The sites were pink at one-month follow-up, returning to normal colouration by three to six months, and remained supple and flexible after transplantation. Unpleasant odour was reported in 4/16 (25%) sites covered with allogeneic cultured keratinocyte sheets and 11/16 (69%) sites covered with OpSite® dressing (Duinslaeger 1997). SECTION 4 z RESULTS 43 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Complications The tables in this section provide information on the comparators and types of skin substitutes in the studies for each category. Biobrane® For the management of burns Study Bioengineered Skin Substitute Comparator Lal 2000 Biobrane Silver sulfadiazine Biobrane Silver sulfadiazine Barret 2000 Gerding 1990 Kumar 2004 TransCyte Cassidy 2005 Biobrane Duoderm No complications were reported in two studies comparing Biobrane® with silver sulfadiazine (Barret 2000a; Gerding 1990) and one study comparing Biobrane®, TransCyte® and silver sulfadiazine (Kumar 2004). Biobrane® failed in 2/34 (6%) patients and was removed early due to non-adherence without suspicion of underlying infection (Lal 2000). After removal, the affected wound area was treated with twice daily silver sulfadiazine dressing changes (Lal 2000). No patients in either group required hospital readmissions or skin grafts (Lal 2000). Kumar (Kumar 2004) compared Biobrane®, TransCyte®, and silver sulfadiazine in paediatric patients with partial thickness burns and reported no complications. Cassidy (Cassidy 2005) did not provide information on complications. For the management of donor sites Study Bioengineered Skin Substitute Comparator Fratianne 1993 Biobrane Allogeneic cultured keratinocyte sheets Still 2003 Biobrane OrCel No major complications were reported in the two studies; however, deaths were reported (Fratianne 1993; Still 2003) (see Mortality section). 44 SECTION 4 z RESULTS - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - TransCyte® For the management of burns Study Bioengineered Skin Substitute Topical Agent / Wound Dressing Noordenbos 1999 TransCyte Silver sulfadiazine Demling & DeSanti 1999 TransCyte Antibiotic ointments and creams Demling & DeSanti 2002 No complications were reported in one study comparing TransCyte® with silver sulfadiazine (Noordenbos 1999). Demling and DeSanti (Demling and DeSanti 1999; Demling and DeSanti 2002) did not provide information on complications. Dermagraft® For the management of burns Study Bioengineered Skin Substitute Topical Agent / Wound Dressing Hansbrough 1997 Dermagraft Allograft Purdue 1997 Spielvogel 1997 Hansbrough (Hansbrough 1997) reported no adverse reactions to Dermagraft®, and no evidence of rejection, early deterioration, or separation from wound. The premature removal of either temporary coverings or autograft occurred in 3/66 (4.5%) patients in the study by Purdue (Purdue 1997) but the reason for removal was not specified. No adverse device effects were reported. No patterns were observed that raised safety issues regarding Dermagraft® (Purdue 1997). No information on complications were provided by Spielvogel (Spielvogel 1997). Integra® For the management of burns Study Bioengineered Skin Substitute Topical Agent / Wound Dressing Peck 2002 Integra Allograft Biobrane Heimbach 1988 Artificial dermis Autograft, allograft, or xenograft No major complications were reported in the two studies (Heimbach 1988; Peck 2002). However, both studies did report deaths (see Mortality section). SECTION 4 z RESULTS 45 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Apligraf® For the management of burns Study Bioengineered Skin Substitute Topical Agent / Wound Dressing Waymack 2000 Apligraf + autograft Autograft Waymack (Waymack 2000) reported no device-related adverse events, infections, and humoral or cellular responses. Autologous cultured skin For the management of burns Study Bioengineered Skin Substitute Topical Agent / Wound Dressing Boyce 1995 Autologous epidermal substitute Autograft Boyce 2002 No complications were reported in the two Boyce studies (Boyce 1995; Boyce 2002). Allogeneic cultured skin For the management of donor sites Study Bioengineered Skin Substitute Topical Agent / Wound Dressing Madden 1996 Cultured epidermal allograft + Adaptic dressing Adaptic dressing Duinslaeger 1997 Allogeneic cultured keratinocyte sheets OpSite dressing There was no evidence of blister formation for donor sites covered with cultured epidermal allograft combined with Adaptic™ dressing (Madden 1996). Blood clot accumulation at a small part of the donor site was reported in 1/16 (6%) patients treated with allogeneic cultured keratinocyte sheets and 2/16 (12.5%) patients treated with OpSite® dressing (Duinslaeger 1997). 46 SECTION 4 z RESULTS - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Mortality Biobrane® For the management of burns No deaths were reported from all five studies {Gerding, 1990 162 /id;Barret, 2000 144 /id;Lal, 2000 172 /id;Kumar, 2004 225 /id;Cassidy, 2005 257 /id}. Biobrane® For the management of donor sites Two studies reported patient deaths (Fratianne 1993; Still 2003). Fratianne (Fratianne 1993) reported two patient deaths (2/10, 20%); one on post-burn day 14 and the other on post-burn day 35. The cause of death was not stated for either patient. For the patient who died on post-burn day 14, the site treated with allogeneic cultured keratinocyte sheets healed in 11 days and the Biobrane® treated site was 50% healed at the time of death, which was slightly longer than the median wound healing time reported (wounds healed in a median six days for sites treated with allogeneic cultured keratinocyte sheets and a median 14 days for the Biobrane® treated sites). For the patient who died on post-burn day 35, the site treated with allogeneic cultured keratinocyte sheets healed in nine days and the Biobrane® treated site healed in 17 days, which was similar to the median wound healing time. Still (Still 2003) reported three patient deaths (3/82, 4%) during their study. However, none of the deaths were considered to be related to the study treatment. TransCyte® For the management of burns No deaths were reported in any of the three studies (Demling and DeSanti 1999; Demling and DeSanti 2002; Noordenbos 1999). Dermagraft® For the management of burns Purdue (Purdue 1997) reported eight patient deaths (8/66, 12%) before completion of the study but the causes were not stated. No deaths were reported from Hansbrough (Hansbrough 1997) and Spielvogel (Spielvogel 1997). Integra® For the management of burns Deaths were reported in both studies (Heimbach 1988; Peck 2002). Of the seven patients in the trial by Peck (Peck 2002), three died (43%); one was due to complications related to smoke inhalation injury and the causes were not stated for two (presumably sepsis). SECTION 4 z RESULTS 47 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Heimbach (Heimbach 1988) reported an overall mortality rate of 13% (20/149). The mortality rate for patients with complete data was also 13% (14/106). These mortality rates were age-related where the children in this study appeared to generally respond well to treatment as opposed to the elderly patients who tolerated burns quite poorly. Most of the deaths were in patients with massive burns or associated with severe smoke inhalation. Apligraf® For the management of burns Waymack (Waymack 2000) did not report any deaths. Autologous cultured skin For the management of burns Boyce (Boyce 1995; Boyce 2002) did not report any deaths. Allogeneic cultured skin For the management of donor sites No deaths were reported from Duinslaeger (Duinslaeger 1997) and Madden (Madden 1996). 48 SECTION 4 z RESULTS - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Cost considerations Integra®, TransCyte® and Biobrane® are currently available for use in Australia (J Greenwood: personal communication, 2005). As of October 2005, the cost of Integra® is $AUS 10.60 per cm2 and TransCyte® is $AUS 5.30 per cm2 (J Greenwood: personal communication, 2005). Sheets of Biobrane® are available in three sizes (5” x 5”, 5” x 15” and 10” x 15”) and the average cost across the three is approximately $AUS 0.30 per cm2 (J Greenwood: personal communication, 2005). Cadaver skin is approximately $AUS 1.70 per cm2 (J Greenwood: personal communication, 2005). Three of the included studies provided some cost information on the treatments used (Demling and DeSanti 2002; Gerding 1990; Still 2003). The cost of OrCel™ is $US 27.80 per cm2 (~$US 1000 per 36cm2), more expensive than Biobrane®, which is $US 0.16 per cm2 ($US 25.15 per 161 cm2) (Still 2003). Gerding (Gerding 1990) based their cost data collection on the assumption that patients followed all of their instructions for wound dressings and kept all of their clinic follow-up visits. The mean cost was significantly lower with the use of Biobrane® ($US 434 (SE: 14)) than treatment with silver sulfadiazine ($US 504 (SE: 24)) for 44 weeks’ follow-up in paediatric and adult patients with partial thickness burns (p<0.05). Demling & DeSanti (Demling and DeSanti 2002) reported significantly lower costs with the use of TransCyte® for partial thickness facial burns compared with the use of antibiotic ointments and creams (Table 26). Table 26. Breakdown of cost information from Demling & DeSanti 2002 Study TransCyte Antibiotics P-value Demling & DeSanti 2002 Mean [SD] US dollars Total cost until healing Nursing costs Cost of supplies (incl. skin substitute cost) Cost of medications $2390 [$290] $240 $1950 $210 $3020 [$350] $1350 $1310 $390 <0.05 <0.05 <0.05 NS NS – not significant. Though cost was not a key search term in this review, a study on the cost of cultured epidermal autografts (CEA) compared with conventional meshed autografts in 20 paediatric patients, with full thickness burns to more than 90% TBSA was found in the initial search strategy (Barret et al. 2000b). Conventional meshed autografts were superior to CEA in terms of total number of operations (8[0.9] vs. 13[1.3] (p<0.05), respectively), length of hospital stay (89 [9.8] days vs. 128[14.3] days (p<0.05), respectively), and cost per patient ($US 178 000[19000] vs. $US 304000[31000] (p<0.05), respectively). SECTION 4 z RESULTS 49 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - 5. Discussion Limitations of the evidence This review of bioengineered skin substitutes was limited by the quantity and quality of the available evidence. Despite the inclusion of 20 RCTs, a number of factors limited the conclusions which could be drawn and prevented statistical pooling: the diversity of skin substitutes and management methods for burns; the lack of a standard comparator; the differences in the techniques used to measure wound healing time and wound closure across the studies. As a consequence, the included studies were categorised into type of bioengineered skin substitute, then by management of donor sites and management of burns, and by age (paediatric or adult). Due to this categorisation, there were only a few studies for each sub-group. This review recognises that due to the relatively rapid developments in burns management and the sudden proliferation of materials, many of the included studies compared bioengineered skin substitutes with what the ‘gold standard’ was at that time, which may not be a valid comparator. Though all evidence was from RCTs (Level II and III-1), the methodological quality of these studies was generally inadequate. Of the 20 included studies, 13 were withinpatient comparisons and seven were parallel comparisons. The advantage of withinpatient comparisons is that it overcomes the potential problems of comparing groups of different patients and the carry-over effects and treatment by period interactions that are inherent in crossover trials have been circumvented, due to the concurrent administration of treatments in the included studies. The majority of the included studies had relatively small sample sizes (all but one study had fewer than 100 patients) and may have lacked the power to detect significant differences between treatments. Follow-up times ranged from 11 days to two years. In most cases, the effects of age on the reported outcomes were unclear, as the results for the paediatric and adult population were grouped together. However, in the studies that categorised patients into age groups, patient age did not appear to significantly influence wound healing time, wound closure and wound infection. The reporting and the percentages of mean TBSA varied and were therefore not good predictors of outcome. It was also not possible to evaluate the effectiveness of bioengineered skin substitutes by burn depth, as outcomes were not reported separately for partial thickness and full thickness burns. Key outcomes, including wound healing time, wound closure, wound infection, pain and cosmesis (scarring) were reported. However, some included studies did not report on all of these outcomes, suggesting the possibility of publication/reporting bias in favour of the experimental groups. 50 SECTION 5 z DISCUSSION - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Several methods were used to measure pain. The Vancouver Scar Scale, Hamilton Burn Scar Rating Scale, Wong-Baker Faces Pain Rating Scale, Oucher Scale and Visual Analogue Scale were validated tools used in most of the studies. However, some studies measured pain subjectively, which may have introduced bias in favour of a particular treatment if the patient or assessor was not blinded. Efficacy outcomes From the included studies, Biobrane® and TransCyte® were used for the management of burns <15% TBSA; TransCyte® was used for the management of burns <20% TBSA; TransCyte®, Dermagraft®, Integra®, Apligraf® and allogeneic cultured skin were used for the management of burns 20-50% TBSA; and Integra® and autologous cultured skin were used for the management of burns >50% TBSA. Biobrane® For the management of burns From the evidence available in the five studies, Biobrane® produced as good results as the comparators (silver sulfadiazine and TransCyte®), with regard to wound infection and wound healing time. The use of Biobrane® required significantly fewer dressing changes and less pain medication than silver sulfadiazine. The rates of wound infection with the use of Biobrane® were comparable to those obtained with silver sulfadiazine, the type of infections reported tended to be local and easily controlled. It has been recommended that Biobrane® should be removed if it is non-adherent, as leaving it in place may increase the risk of invasive wound infection (Lal et al. 2000). Wound infection may be related to the mechanism of burn injury, as this influences the severity of the wound. The reporting of wound infections in Gerding et al. (1990) and the lack of wound infections in Barret et al. (2000a) suggests that wound infections are more likely to occur in grease-related injuries rather than scalds. The higher temperatures, increased viscosity and enhanced heat transfer associated with burns caused by grease may induce deeper injuries than aqueous-based scalds; whereas contact burns generally have a limited depth of heat penetration and are less likely to deepen with time and become infected (Gerding et al. 1990). Therefore the outcomes reported from different causes of burn injury may not be comparable. Unlike silver sulfadiazine, Biobrane® is not toxic to keratinocytes, which may explain the significantly faster wound healing time reported for partial thickness burns covered with Biobrane® than those covered with silver sulfadiazine. Partial thickness burn sites on paediatric patients treated with silver sulfadiazine tended to require skin grafting to close the wound compared with sites covered with Biobrane® or TransCyte®. Kumar et al. (2004) noted that paediatric patients appeared to respond better with the use of Biobrane® or TransCyte®, as the dressings were usually left SECTION 5 z DISCUSSION 51 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - intact on the wound until separation; this reduced the pain and anxiety associated with dressing changes and allowed the wound to heal undisturbed underneath, resulting in the shorter wound healing times reported. Wound healing times were comparable for Biobrane® and Duoderm®. Biobrane® required significantly fewer dressing changes than silver sulfadiazine. As a result, patients reported less pain at the Biobrane® site and significantly less pain medication was required. Patients who received silver sulfadiazine treatment were not as compliant as the Biobrane® treated patients, which may have been attributable to the more frequent and painful dressing changes required with silver sulfadiazine treatment. For the management of donor sites Although Biobrane® is not frequently used for the management of donor sites, evidence was obtained from two studies, as they provided evidence on the properties of Biobrane® on a clean and controlled wound. From the evidence available in the two studies, Biobrane® did not produce results as good as the other products (allogeneic cultured keratinocytes and OrCel™), with regard to wound healing time, wound closure, pain and scar severity. Wound infection appears to be comparable for Biobrane® and OrCel™. Donor sites covered with Biobrane® took a longer time to heal than sites covered with allogeneic cultured keratinocyte sheets or OrCel™. Compared with Biobrane®, a higher percentage of OrCel™ sites were completely healed and had a faster rate of wound closure, enabling these sites to be ready for recropping earlier (none of the Biobrane® sites were reharvested). The scar severity score was lower for OrCel™ and patients reported less pain from OrCel™ covered sites. There were no significant differences in wound infection between OrCel™ and Biobrane®. The outcomes reported with the use of OrCel™ and the allogeneic cultured keratinocyte sheets suggests that the presence of cytokines and growth factors produced by the proliferating keratinocyte and fibroblast donor cells may have a positive influence on the wound healing process. TransCyte® From the evidence available in the three studies, TransCyte® performed more favourably than topical antibiotics in terms of wound healing time, wound care time and pain. Similarly, TransCyte® produced more favourable results over silver sulfadiazine, in terms of wound infection, wound healing time, wound closure and scar severity. For facial burns, TransCyte® appeared to be superior to antibiotic ointments and creams, with a significantly shorter wound healing time and fewer dressing changes required. The physical properties of TransCyte® are very similar to skin and allow it 52 SECTION 5 z DISCUSSION - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - to mould to the facial contour. TransCyte® reportedly had good adherence to the entire face including the ears, which could be attributable to biochemical bonding; in particular, the bonding of the adhesion protein, fibronectin, to the wound surface (Demling and DeSanti 1999). Dermagraft® From the evidence available in the three studies, Dermagraft® appeared to produce results as good as allograft, with regard to wound infection, wound exudate, wound healing time, wound closure and graft take. Dermagraft® had comparable results with allograft, but was easier to remove; a significantly higher level of patient satisfaction with Dermagraft® was also reported. A higher proportion of wounds covered with allograft had granulation tissue present, but removing the allograft required surgical excision and de-sloughing (removal of necrotic tissue). The advantages of Dermagraft® are that it is transparent, which allows direct visual monitoring of the wound bed and therefore permits earlier detection of clinical signs of wound infection, and it induces less granulation tissue formation and less bleeding on removal. Hansbrough et al. (1997) also compared two different Dermagraft® products: Dermgraft® red, which was cryopreserved by a method that maintains high viability of the cultured fibroblasts, and Dermagraft® blue, which was frozen by a method that did not retain metabolic activity. Both were functionally equivalent, suggesting that continued fibroblast viability is not required for these skin substitutes to function as a temporary wound cover. Integra® From the evidence available in the two studies, Integra® did not produce as good results as the other products (autograft, allograft, xenograft, Biobrane®), with regard to wound infection and graft take. However, Integra® appeared to be better than autograft, allograft or xenograft in terms of wound healing time. Results from the trial by Peck et al. (2002) appeared to be in favour of Biobrane® and allograft, as all Integra® covered sites developed infections and, as a consequence, the trial was terminated early. This suggests that Integra® may not be effective on patients with burns more than 45% TBSA due to host immunosuppression and may be better suited to selected patients with smaller burns (Peck et al. 2002). However, in clinical practice, the use of Integra® is usually limited to major burns when there is no alternative due to a lack of available donor area for autografting and would therefore not be used on smaller burns. Heimbach et al. (1988) reported a significantly shorter wound healing time with Integra®; however, covering the wound with either an allograft or xenograft, prior to SECTION 5 z DISCUSSION 53 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - grafting, resulted in significantly better graft take. There appeared to be a learning curve with the use of Integra®, and graft take improved as the surgeons became more experienced (Heimbach et al. 1988). Apligraf® From the evidence available in the one study, Apligraf® combined with autograft produced more favourable results than autograft only. The rate of wound closure was accelerated, and scar tissue, pigmentation, pliability and smoothness were significantly closer to normal with Apligraf®. Autologous cultured skin From the evidence available in the two studies, autograft appeared to be superior to autologous epidermal substitute in terms of graft take, wounds with exudate and scar appearance. More sites covered with autologous epidermal substitute required regrafting. The main disadvantage with the use of cultured and non-cultured skin products is that these take weeks to prepare after collection of the biopsy for cell culture. For burns this is not ideal but these may be more suitable for elective procedures, such as reconstruction of burn scar or congenital skin lesions (Boyce et al. 2002). Allogeneic cultured skin From the evidence available in the one study, allogeneic cultured keratinocyte sheets produced favourable results compared with OpSite® dressing, with regard to wound healing time, re-epithelialisation rates, wounds with exudate and pain score. In another study, cultured epidermal allograft combined with Adaptic™ dressing produced comparable results when compared with Adaptic™ dressing only. The use of allogeneic cultured keratinocytes resulted in a significantly shorter wound healing time and significantly greater percentage of epithelialisation compared with the use of OpSite® dressing (Duinslaeger et al. 1997). However, the degree of epithelialisation was determined by visual estimation in this RCT and such subjective methods could result in possible errors that could influence the wound healing time. Sites covered with OpSite® dressing took the longest time to heal, had a higher proportion of wounds with exudate and unpleasant odour, and a significantly higher pain score. This would have been associated with the frequent dressing changes required, which are often painful and may injure viable tissue and remove the delicate, newly formed epithelial cells, and as a result, would make the wound susceptible to infection. For both treatment sites, there were a few cases of mild hypertrophic scarring but no cases of infection were reported. Madden et al. (1996) developed a method to cryopreserve cultured epidermal allografts suitable for grafting because, until recently, the use of cultured epidermal 54 SECTION 5 z DISCUSSION - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - allografts was limited; they could only be supplied fresh to the surgeon. Sites covered with cultured epidermal allograft plus Adaptic™ dressing had a significantly greater degree of re-epithelialisation and enhanced epithelial differentiation, and a significantly shorter wound healing time compared with those covered with Adaptic™ dressing alone. Pain assessment and scar assessment results were equivalent between the two groups. Biological skin replacements The most commonly used temporary cover is frozen cadaver allograft (Heimbach et al. 1988). It is often used as an overlay on widely spread autografts to close the wound and as the autografted epidermis spreads, it gradually dislodges the allograft (the Alexander technique). Though the wound usually closes successfully, the cosmetic and functional results remain poor (Heimbach et al. 1988). Xenografts are commonly of porcine origin and are generally effective at preparing the wound bed for a short time (seven days) but do not vascularise and thus offer little resistance to infection (Heimbach et al. 1988). Autografts are still the gold standard for the management of burns, as there are no issues with graft rejection and viral contamination. However, some bioengineered skin substitutes can be used with autograft; (i) as temporary coverings with/without other dressings to prepare and maintain the post-burn excision wound until the time for autografting, (ii) as agents to hold meshed autograft in areas of shear or to stimulate the wound bed in the interstices of meshed autograft and (iii) as permanent dermal replacements to provide a neo-dermal base onto which autograft can be applied. Safety outcomes No major complications were reported with the use of Biobrane®. One RCT reported Biobrane® failure in 6% of patients due to non-adherence without suspicion of underlying infection. After the removal of Biobrane®, the sites healed uneventfully with silver sulfadiazine dressings. The mortality rate was high with patient deaths reported in the Biobrane®/allogeneic cultured keratinocyte sheets study and in the Biobrane®/OrCel™ study. However, there was no evidence that mortality was influenced by the choice of dressing. Early removal was required in 4.5% of patients with Dermagraft® or allograft coverings, but reasons for removal were not stated. Patient deaths were also reported in the Dermagraft®/allograft study but the causes were not stated. The mortality rate was also very high for the studies involving the use of Integra®, and was associated with smoke inhalation injury or large TBSA. The remaining studies did not report any major complications or deaths. SECTION 5 z DISCUSSION 55 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Cost considerations Though cost was not a key search term in this review, a U.S. cost study published in 2000 was found in the initial search strategy (Barret et al. 2000b). Barret et al. (2000b) reported that the mean cost for conventional meshed autografts, which included total number of operations and length of hospital stay, was significantly lower per patient than for mean cultured epidermal autografts per patient. As of October 2005, Biobrane® appears to be the least expensive bioengineered skin substitute available in Australia (J Greenwood: personal communication, 2005). In the U.S., Biobrane® was also less expensive than OrCel™ (per cm2) (Still et al. 2003) and treatment with silver sulfadiazine (total cost over 44 weeks) (Gerding et al. 1990). Demling & DeSanti (Demling and DeSanti 2002) reported significantly lower total costs with the use of TransCyte® for 19 days than the use of topical antibiotics over the same period of time. Further investigation of the cost-effectiveness of the bioengineered skin substitutes available in Australia compared with conventional methods of burns management are required. Ethical considerations There are ethical and or religious concerns associated with the use of skin substitutes, which should be considered in the management of burns patients. The use of donor organs or animal tissue may raise issues for ethnic or religious groups, vegans, vegetarians and animal rights activists. A U.K. study (Enoch et al. 2005) found that religious leaders, representing 13 religious groups encompassing 75% of the U.K. population, had concerns regarding bioengineered skin substitutes including the transmission of viral and prion diseases, cruelty to animals, and derivation of material from neonates. These leaders emphasised the need to inform the patient of the constituents of the biological products and obtain informed consent. However, healthcare professionals may be unfamiliar with all the constituents of bioengineered skin substitutes (Enoch et al. 2005), which would make it difficult to appropriately inform patients when obtaining consent. Thus, hospitals, regulatory authorities and product manufacturers should address this issue and take adequate measures to ensure that healthcare professionals are aware of the constituents of these products in order to obtain informed patient consent, as the failure to do so could have potentially serious ramifications. Future research Obtaining useful evidence from comparative studies of the use of bioengineered skin substitutes for burns management is difficult. Although 20 RCTs were included in this systematic review, the numerous types of bioengineered skin substitutes available have prevented statistical pooling of the results. There is a need to develop a tool to non-invasively and objectively measure the biophysical properties of skin to avoid 56 SECTION 5 z DISCUSSION - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - biases associated with the use of subjectively scoring wound closure. More rigorous RCTs are required comparing burn coverings with similar properties to enable valid comparisons of outcomes. Studies should also specify where in the clinical decision pathway is the bioengineered skin substitute employed and report separate outcomes for partial thickness and full thickness burns. There are also a number of autologous cultured and non-cultured skin engineering products available, such as CellSpray®, Cellspray® XP and ReCell® (Clinical Cell Culture Ltd., Bentley, Australia) and EpiDex™ (Modex Therapeutiques, Lausanne, Switzerland) (Table 1). However, there is a paucity of published, high quality evidence to allow the safety and efficacy of these products to be evaluated. Randomised controlled trials are needed before the safety and efficacy of these products can be determined. SECTION 5 z DISCUSSION 57 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - 6. Conclusions and Recommendations This review compared bioengineered skin substitutes and biological skin replacements or topical agents/wound dressings in terms of safety and efficacy. Despite the inclusion of 20 randomised controlled trials, which should have minimised bias in the reporting of outcomes, these trials were characterised by generally poor reporting of methodological detail and small sample sizes. Consequently, it was difficult to be confident in the validity of some of the findings. More rigorous RCTs are required comparing burn coverings with similar properties to enable valid comparisons of outcomes. Overall conclusions regarding the suitability of BSS for burns management could not be formulated based on the evidence in this review, due to the diversity of skin substitutes and methods for burn management. Due to the way in which outcomes were reported in the included studies, it was not possible to investigate differences in the effectiveness of bioengineered skin substitutes in partial thickness compared with full thickness burns, in paediatric patients compared to adult patients, and for TBSA. However, from the available evidence it was possible to draw some conclusions about the different bioengineered skin substitutes considered in the review. For partial thickness burns (less than 15%TBSA), Biobrane® and TransCyte® appear to be more effective than silver sulfadiazine, avoiding the need for painful daily dressing changes and prolonged hospital stay. Biobrane® may also offer cost advantages over other bioengineered skin substitutes. For burns between 20% and 50% TBSA, allogeneic cultured skin and Apligraf® combined with autograft both appear to be effective. Dermagraft® was also found to be effective for partial and full thickness burns (as effective as allograft); however, the validity of this comparison is questionable as Dermagraft® is permanently integrated whereas allograft is a temporary biological dressing. Integra® may be better suited to selected patients with burns less than 45% TBSA due to the high rates of infection reported in one study managing patients with burns greater than 45% TBSA. However, in clinical practice, Integra® is commonly used in the treatment of major burn injury where a paucity of available donor area precludes early autografting. Its successful take still has to be followed by definitive epidermal closure (by autograft or cultured epithelial autograft). TransCyte® appears to be good for facial burns, providing good adherence to the contours of the face. However, considerations with the storage, pre-use preparation and high cost of TransCyte® may limit its clinical use. In terms of safety, no major complications were reported with the use of bioengineered skin substitutes for the management of burns or donor sites. The 58 SECTION 6 z CONCLUSIONS AND RECOMMENDATIONS - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - mortality rate was relatively high; however, it was unclear whether these deaths could be attributed to the use of the bioengineered skin substitute or the actual burn injury. In practical terms, this distinction would be difficult to assess since the use of bioengineered skin substitutes is largely confined to patients with larger TBSA burn areas, more complicated pathophysiological insults and significantly poorer prognoses. The available evidence could not resolve the question of the long-term safety of bioengineered skin substitutes with respect to viral infection and prion disease. To address this issue, long-term follow-up is required as the incubation period for viral infection and prion disease has been estimated to be approximately 15 to 18 years (Ghani 2002). Thus, at present, autograft remain the gold standard for the management of excised burns as it is effective at closing the wound and there are no issues with graft rejection and viral contamination. Classification and Recommendations The evidence-base in this review is rated as average. The included randomised controlled trials were limited by small sample size and poor reporting of methodological detail. The numerous sub-groups analyses and the diversity of skin substitutes limited the ability to draw any conclusions from it. Safety The evidence suggests that bioengineered skin substitutes, namely Biobrane®, TransCyte®, Dermagraft®, Apligraf®, autologous cultured skin, and allogeneic cultured skin, are at least as safe as biological skin replacements or topical agents/wound dressings. The safety of Integra® could not be determined as one study reported a high rate of infection and the trial was terminated early. The long-term safety of the use of bioengineered skin substitutes, with respect to viral infection and prion disease, could not be determined. Efficacy For the management of partial thickness burns the evidence suggests that bioengineered skin substitutes, namely Biobrane®, TransCyte®, Dermagraft®, and allogeneic cultured skin, are at least as efficacious as topical agents/wound dressings or allograft. Apligraf® combined with autograft is at least as efficacious as autograft alone. For the management of full thickness burns, the efficacy of autologous cultured skin could not be determined based on the available evidence. The efficacy of Integra® could not be determined based on the available evidence. SECTION 6 z CONCLUSIONS AND RECOMMENDATIONS 59 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Clinical and Research Recommendations Additional methodologically rigorous randomised controlled trials would strengthen the evidence base for the use of bioengineered skin substitutes. However, it is acknowledged that it is unlikely that randomised trials of patients with large, deep burns will be carried out, as these burns are uncommon and usually involve complex clinical decision pathways and possibly the use of several products, which may differ between patients and make comparisons difficult. Therefore, it is recommended that randomised trials of patients with smaller burns be undertaken as these burns are more common and patient accrual should be easier. Furthermore, clinical equipoise should be more easily obtained in these less life-threatening situations. Additionally, studies with sufficient follow-up should be conducted to evaluate the long-term safety of bioengineered skin substitutes and future studies should define and document outcomes for partial and full thickness burns separately. There is also a need for randomised controlled trials on cultured epithelial autograft, in particular cultured epithelial autograft suspensions, as there is a lack of evidence to support its safety and efficacy and its use largely based on anecdote. Acknowledgments The authors wish to acknowledge Dr Rebecca Tooher, Ms Amber Watt and Ms Philippa Middleton for their assistance during the preparation of this review. The ASERNIP-S project is funded by the Australian Government Department of Health and Ageing. 60 SECTION 6 z CONCLUSIONS AND RECOMMENDATIONS - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - References Australia and New Zealand Burn Association Ltd. 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Purdue GF, Hunt JL, Still JM, Jr., Law EJ, Herndon DN, Goldfarb IW, Schiller WR, Hansbrough JF, Hickerson WL, Himel HN, Kealey GP, Twomey J, Missavage AE, Solem LD, Davis M, Totoritis M, Gentzkow GD. A multicenter clinical trial of a biosynthetic skin replacement, Dermagraft-TC, compared with cryopreserved human cadaver skin for temporary coverage of excised burn wounds. Journal of Burn Care & Rehabilitation 1997; 18(1 Pt 1): 5257. Rheinwald JG and Green H. Serial cultivation of strains of human epidermal keratinocytes: the formation of keratinising colonies from single cells. Cell 1975; 6(3): 331-343. Spann CT, Tutrone WD, Weinberg JM, Scheinfeld N, Ross B. Topical antibacterial agents for wound care: a primer. Dermatologic Surgery 2003; 29(6): 620-626. Spielvogel RL. A histological study of Dermagraft-TC in patients' burn wounds. Journal of Burn Care & Rehabilitation 1997; 18(1 Pt 2): S16-S18. Still J, Glat P, Silverstein P, Griswold J, Mozingo D. The use of a collagen sponge/living cell composite material to treat donor sites in burn patients. Burns 2003; 29(8): 837-841. Subrahmanyam M. A prospective randomised clinical and histological study of superficial burn wound healing with honey and silver sulfadiazine. Burns 1998; 24(2): 157-161. Takeuchi J, Miura K, Usizima H, Katoh Y. Histological changes in the submandibular glands of rats after intraductal injection of chemical carcinogens. Acta Pathologica Japonica 1975; 25(1): 1-13. Therapeutic Goods Administration. Access to unapproved therapeutic goods via the special access scheme. Department of Health and Ageing. Last updated October 2004a. http://www.tga.gov.au/docs/html/sasinfo.htm [Accessed May 2006a]. 64 REFERENCES - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Therapeutic Goods Administration. Regulatory impact statement for human cell, tissue and cellular and tissue-based products. Department of Health and Ageing. Last updated September 2004b. http://www.tga.gov.au/consult/2004/hctpris.htm#pdf [Accessed May 2006b]. Waymack P, Duff RG, Sabolinski M. The effect of a tissue engineered bilayered living skin analog, over meshed split-thickness autografts on the healing of excised burn wounds. The Apligraf Burn Study Group. Burns 2000; 26(7): 609-619. REFERENCES 65 APPENDIX A – HIERARCHY OF EVIDENCE - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Appendix A – Hierarchy Of Evidence Level of Evidence Study Design I Evidence obtained from a systematic review of all relevant randomised controlled trials. II Evidence obtained from at least one properly designed randomised controlled trial. III-1 Evidence obtained from well-designed pseudo-randomised controlled trials (alternate allocation or some other method). III-2 Evidence obtained from comparative studies (including systematic reviews of such studies) with concurrent controls and allocation not randomised, cohort studies, case-control studies, or interrupted timeseries with a control group. III-3 Evidence obtained from comparative studies with historical control, two or more single arm studies, or interrupted time series without a parallel control group. IV Evidence obtained from case-series, either post-test or pre-test/post-test. National Health and Medical Research Council. How to use the evidence: assessment and application of scientific evidence. Canberra, ACT: Biotext, 2000. 68 APPENDIX B – EXCLUDED STUDIES 69 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Appendix B – Excluded Studies The following articles were excluded from the methodological assessment as outlined in the methods section of the review. Excluded Studies Study Reason for exclusion Arnold K. Out-patient care of scalds and burns with SYSpur-derm. Dermatologische Monatsschrift 1981; 167(10): 647 Assessment of outpatient care – no useful outcomes Asai S, Ino K, Ebisawa K, Torii S. Simultaneous grafting for burn injuries using artificial dermis and skin. [Japanese]. Japanese Journal of Plastic & Reconstructive Surgery 2001; 44(1): 27-34 Not a comparative study Asato H, Harii K, Nozaki M. Clinical evaluation of Pelnuc (Artificial dermis) for full-thickness skin defects. [Japanese]. Japanese Journal of Plastic & Reconstructive Surgery 2001; 44(4): 359-376 Not a comparative study Barret JP, Wolf SE, Desai MH, Herndon DN. Cost-efficacy of cultured epidermal autografts in massive pediatric burns. Annals of Surgery 2000; 231(6): 869-875 Non-randomised comparative study Berger A and Burke JF. Autologous skin transplantation versus artificial skin. Langenbecks Archiv fur Chirurgie 1987; 372: 343-348 Non-randomised comparative study Bortolami PA, Guerrini P, Sanna A. A new type of dressing for skin donor areas. Rivista Italiana di Chirurgia Plastica 1983; 15(1): 50-53 Not a comparative study Boyce ST, Kagan RJ, Meyer NA, Yakuboff KP, Warden GD. Cultured skin substitutes combined with integra artificial skin to replace native skin autograft and allograft for the closure of excised full- thickness burns. Journal of Burn Care & Rehabilitation 1999; 20(6): 453-461 Not a comparative study Bugmann P, Taylor S, Gyger D, Lironi A, Genin B, Vunda A, La Scala G, Birraux J, Le Coultre C. A silicone-coated nylon dressing reduces healing time in burned paediatric patients in comparison with standard sulfadiazine treatment: a prospective randomized trial. Burns 1998; 24(7): 609-612 No comparison with a bioengineered skin substitute Carsin H. Cultured skin in the treatment of burns. Pathologie Biologie 1999; 47(8): 776-779 Not a comparative study Carsin H, Ainaud P, Le Bever H, Rives JM, Lakhel A, Stephanazzi J, Lambert F, Perrot J. Cultured epithelial autografts in extensive burn coverage of severely traumatized patients: a five year single-center experience with 30 patients. Burns 2000; 26(4): 379-387 Not a comparative study Caruso DM, Foster KN, Hermans MHE, Rick C. Aquacel Ag (R) in the management of partial-thickness burns: Results of a clinical trial. Journal of Burn Care & Rehabilitation 2004; 25(1): 89-97 Non-randomised comparative study Caruso DM, Schuh WH, Al Kasspooles MF, Chen MC, Schiller WR. Cultured composite autografts as coverage for an extensive body surface area burn: case report and review of the technology. Burns 1999; 25(8): 771-779 Not a comparative study Chan ESY, Lam PK, Liew CT, Lau HCH, Yen RSC, King WWK. A new technique to resurface wounds with composite biocompatible epidermal graft and artificial skin. Journal of Trauma-Injury Infection & Critical Care 2001; 50(2): 358-362 Not a comparative study Chen X, Soejima K, Kikuchi Y, Nozaki M. Effects of artificial dermis seeded with cryopreserved allogenic cultured dermal fibroblasts on wound healing. [Japanese]. Japanese Journal of Plastic & Reconstructive Surgery 2002; 45(11): 1061-1067 Not in humans (rats) 70 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Dantzer E and Braye FM. Reconstructive surgery using an artificial dermis (Integra): results with 39 grafts. British Journal of Plastic Surgery 2001; 54(8): 659-664 Not a comparative study Dantzer E, Queruel P, Salinier L, Palmier B, Quinot JF. Dermal regeneration template for deep hand burns: clinical utility for both early grafting and reconstructive surgery. British Journal of Plastic Surgery 2003; 56(8): 764-774 Not a comparative study Degenhardt P, Marzheuser S, Mau H. First experiences with use of artificial dermis (Integra) on soft tissue wounds in children. [German]. Zentralblatt fur Kinderchirurgie 2002; 11(1): 17-21 Not a comparative study Druecke D, Lamme EN, Hermann S, Pieper J, May PS, Steinau HU, Steinstraesser L. Modulation of scar tissue formation using different dermal regeneration templates in the treatment of experimental full-thickness wounds. Wound Repair and Regeneration 2004; 12(5): 518-527 Not in humans Elliott M and Vandervord J. Initial experience with cultured epithelial autografts in massively burnt patients. ANZ Journal of Surgery 2002; 72(12): 893-895 Not a comparative study Feldman DL, Rogers A, Karpinski RH. A prospective trial comparing Biobrane, Duoderm and xeroform for skin graft donor sites. Surgery, Gynecology & Obstetrics 1991; 173(1): 1-5 Not on burns Fitton AR, Drew P, Dickson WA. The use of a bilaminate artificial skin substitute (Integra) in acute resurfacing of burns: An early experience. British Journal of Plastic Surgery 2001; 54(3): 208-212 Not a comparative study Frame JD, Still J, Lakhel-LeCoadou A, Carstens MH, Lorenz C, Orlet H, Spence R, Berger AC, Dantzer E, Burd A. Use of dermal regeneration template in contracture release procedures: A multicenter evaluation. Plastic & Reconstructive Surgery 2004; 113(5): 1330-1338 Not a comparative study Gerding RL, Imbembo AL, Fratianne RB. Biosynthetic skin substitute vs. 1% silver sulfadiazine for treatment of inpatient partial-thickness thermal burns. Journal of Trauma 1988; 28(8): 1265-1269. Non-randomised comparative study Gohari S, Gambla C, Healey M, Spaulding G, Gordon KB, Swan J, Cook B, West DP, Lapiere JC. Evaluation of tissue-engineered skin (human skin substitute) and secondary intention healing in the treatment of full thickness wounds after Mohs micrographic or excisional surgery. Dermatologic Surgery 2002; 28(12): 1107-1114 Not on burns Healy CM and Boorman JG. Comparison of E-Z Derm and Jelonet dressings for partial skin thickness burns. Burns, Including Thermal Injury 1989; 15(1): 52-54 No comparison with a bioengineered skin substitute Heitland A, Piatkowski A, Noah EM, Pallua N. Update on the use of collagen/glycosaminoglycate skin substitute - Six years of experiences with artificial skin in 15 German burn centers. Burns 2004; 30(5): 471-475 Not a comparative study Hunt JA, Moisidis E, Haertsch P. Initial experience of Integra in the treatment of post-burn anterior cervical neck contracture. British Journal of Plastic Surgery 2000; 53(8): 652-658 Not a comparative study Kaiser HW, Stark GB, Kopp J, Balcerkiewicz A, Spilker G, Kreysel HW. Cultured autologous keratinocytes in fibrin glue suspension, exclusively and combined with STS-allograft (preliminary clinical and histological report of a new technique). Burns 1994; 20(1): 23-29 Not a comparative study 71 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Kashiwa K and Minato S. The clinical use of a new artificial dermis (PELNAC(TM)). Japanese Pharmacology & Therapeutics 1996; 24(8): 229241 Not a comparative study Kashiwa N, Ito O, Ueda T, Kubo K, Matsui H, Kuroyanagi Y. Treatment of full-thickness skin defect with concomitant grafting of 6-fold extended mesh auto-skin and allogeneic cultured dermal substitute. Artificial Organs 2004; 28(5): 444-450 Not a comparative study Khan U, Rhoer S, Healy C. Use of biobrane in pediatric scald burns experience in 106 children by L. F. Ou, S.Y. Lee, Y.C. Chen, R.S. Yang, Y.W. Tang. Burns 1998; 24(8): 770 Not a comparative study (letter) King P. Artificial skin reduces nutritional requirements in a severely burned child. Burns 2000; 26(5): 501-503 Not a comparative study Klein RL, Rothmann BF, Marshall R. Biobrane. A useful adjunct in the therapy of outpatient burns. Journal of Pediatric Surgery 1984; 19(6): 846847 Not a comparative study Kurihara K, Goto S, Namikawa H, Takahaski M, Nakamura J, Sasaki Y. Clinical experiences using an artificial dermis. Japanese Journal of Plastic & Reconstructive Surgery 1995; 38(6): 567-573 Not a comparative study Lei X, Wu J-J, Zhu T-Y, Lu Y-G. Effects of composite chitosan artificial skin in accelerating wound healing. Zhongguo Linchuang Kangfu 2004; 8(17): 3300-3302 Not a comparative study Leicht P, Muchardt O, Jensen M, Alsbjorn BA, Sorensen B. Allograft vs. exposure in the treatment of scalds--a prospective randomized controlled clinical study. Burns, Including Thermal Injury 1989; 15(1): 1-3 No comparison with a bioengineered skin substitute Loss M, Wedler V, Kunzi W, Meuli-Simmen C, Meyer VE. Artificial skin, split-thickness autograft and cultured autologous keratinocytes combined to treat a severe burn injury of 93% of TBSA. Burns 2000; 26(7): 644-652 Not a comparative study Lukish JR, Eichelberger MR, Newman KD, Pao M, Nobuhara K, Keating M, Golonka N, Pratsch G, Misra V, Valladares E, Johnson P, Gilbert JC, Powell DM, Hartman GE. The use of a bioactive skin substitute decreases length of stay for pediatric burn patients. Journal of Pediatric Surgery 2001; 36(8): 1118-1121 No comparison with a bioengineered skin substitute Mann R, Gibran NS, Engrav LH, Foster KN, Meyer NA, Honari S, Costa BA, Heimbach DM. Prospective trial of thick vs standard split-thickness skin grafts in burns of the hand. Journal of Burn Care & Rehabilitation 2001; 22(6): 390-392 No comparison with a bioengineered skin substitute Medina J, de Brugerolle dF, Chibout SD, Kolopp M, Kammermann R, Burtin P, Ebelin ME, Cordier A. Use of human skin equivalent Apligraf for in vitro assessment of cumulative skin irritation potential of topical products. Toxicology & Applied Pharmacology 2000; 164(1): 38-45 Not on burns – investigating skin irritations in healthy volunteers Moiemen NS, Staiano JJ, Ojeh NO, Thway Y, Frame JD. Reconstructive surgery with a dermal regeneration template: Clinical and histologic study. Plastic and Reconstructive Surgery 2001; 108(1): 93-103 Not a comparative study Monstrey S, Beele H, Kettler M, Van Landuyt K, Blondeel P, Matton G, Naeyaert JM. Allogeneic cultured keratinocytes vs. cadaveric skin to cover wide-mesh autogenous split-thickness skin grafts. Annals of Plastic Surgery 1999; 43(3): 268-272 No comparison with a bioengineered skin substitute Ohura T. The clinical study of NEOMATRIX (artificial dermis) for full thickness skin defects. Japanese Pharmacology & Therapeutics 1995; 23(6): 171-184 Not a comparative study 72 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Ou LF, Lee SY, Chen YC, Yang RS, Tang YW. Use of Biobrane in pediatric scald burns - experience in 106 children. Burns 1998; 24(1): 4953 Not a comparative study Paddle-Ledinek JE, Cruickshank DG, Masterton JP. Skin replacement by cultured keratinocyte grafts: an Australian experience. Burns 1997; 23(3): 204-211 Not a comparative study Pandya AN, Woodward B, Parkhouse N. The use of cultured autologous keratinocytes with integra in the resurfacing of acute burns. Plastic and Reconstructive Surgery 1998; 102(3): 825-828 Not a comparative study Pape SA. Safety and efficacy of TransCyte for the treatment of partialthickness burns. Journal of Burn Care & Rehabilitation 2000; 21(4): 390 Not a comparative study (letter) Phillips TJ, Provan A, Colbert D, Easley KW. A randomized single-blind controlled study of cultured epidermal allografts in the treatment of splitthickness skin graft donor sites. Archives of Dermatology 1993; 129(7): 879-882 Not on burns Porter JM. A comparative investigation of re-epithelialisation of split skin graft donor areas after application of hydrocolloid and alginate dressings. British Journal of Plastic Surgery 1991; 44(5): 333-337 Not on burns Prasad JK, Feller I, Thomson PD. A prospective controlled trial of Biobrane versus scarlet red on skin graft donor areas. Journal of Burn Care & Rehabilitation 1987; 8(5): 384-386 RCT but scarlet red is no longer used and is therefore not a valid comparator Purdue GF, Hunt JL, Gillespie RW, Hansbrough JF, Dominic WJ, Robson MC, Smith DJ, MacMillan BG, Waymac JP, Herndon DN. Biosynthetic skin substitute versus frozen human cadaver allograft for temporary coverage of excised burn wounds. Journal of Trauma-Injury Infection & Critical Care 1987; 27(2): 155-157. Non-randomised comparative study Putland M, Snelling CFT, Macdonald I, Tron VA. Histologic comparison of cultured epithelial autograft and meshed expanded split-thickness skin graft. Journal of Burn Care & Rehabilitation 1995; 16(6): 627-640 Not a comparative study Qaryoute S, Mirdad I, Hamail AA. Usage of autograft and allograft skin in treatment of burns in children. Burns 2001; 27(6): 599-602 Not a comparative study Rose JK, Desai MH, Mlakar JM, Herndon DN. Allograft is superior to topical antimicrobial therapy in the treatment of partial-thickness scald burns in children. Journal of Burn Care & Rehabilitation 1997; 18(4): 338341 No comparison with a bioengineered skin substitute Rubis BA, Danikas D, Neumeister M, Williams WG, Suchy H, Milner SM. The use of split-thickness dermal grafts to resurface full thickness skin defects. Burns 2002; 28(8): 752-759 Not in humans Rue III LW, Cioffi WG, McManus WF, Pruitt Jr BA. Wound closure and outcome in extensively burned patients treated with cultured autologous keratinocytes. Journal of Trauma-Injury Infection & Critical Care 1993; 34(5): 662-668 Not a comparative study Ryan CM, Schoenfeld DA, Malloy M, Schulz III JT, Sheridan RL, Tompkins RG. Use of Integra artificial skin is associated with decreased length of stay for severely injured adult burn survivors. Journal of Burn Care & Rehabilitation 2002; 23(5): 311-317 Not a comparative study Sheridan RL, Hegarty M, Tompkins RG, Burke JF. Artificial skin in massive burns - Results to ten years. European Journal of Plastic Surgery 1994; 17(2): 91-93 Not a comparative study Soejima K, Nozaki M, Mizuno M. Artificial skin grafts with cryopreserved allogenic cultured dermal fibroblasts. Japanese Journal of Plastic & Reconstructive Surgery 2001; 44(1): 35-41 Not a comparative study 73 - ASERNIP-S REVIEW OF BIOENGINEERED SKIN SUBSTITUTES FOR THE MANAGEMENT OF BURNS AUGUST 2006 - Soejima K, Nozaki M, Sasaki K, Takeuchi M, Negishi N. Reconstruction of burn deformity using artificial dermis combined with thin split-skin grafting. Burns 1997; 23(6): 501-504 Not a comparative study Steenfos HH and Agren MS. A fibre-free alginate dressing in the treatment of split thickness skin graft donor sites. Journal of the European Academy of Dermatology & Venereology 1998; 11(3): 252-256 Not on burns Stern R, McPherson M, Longaker MT. Histologic study of artificial skin used in the treatment of full-thickness thermal injury. Journal of Burn Care & Rehabilitation 1990; 11(1): 7-13 Not a comparative study Still JM and Craft-Coffman B. Graftskin (APLIGRAF) in the management of thermal injury. Wounds: A Compendium of Clinical Research and Practice 2000; 12(5): Suppl-63A Not a comparative study Subrahmanyam M. A prospective randomised clinical and histological study of superficial burn wound healing with honey and silver sulfadiazine. Burns 1998; 24(2): 157-161 No comparison with a bioengineered skin substitute Suzuki S. Clinical application of NEOMATRIX for deep dermal defect. Japanese Pharmacology & Therapeutics 1995; 23(6): 185-194 Not a comparative study Suzuki S, Matsuda K, Maruguchi T, Nishimura Y, Ikada Y. Further applications of 'bilayer artificial skin'. British Journal of Plastic Surgery 1995; 48(4): 222-229 Not a comparative study Takami Y, Tanaka H, Wada T, Shimazaki S, Ogo K. Clinical trial of artificial dermis transplantation and simultaneous autologous skin graft overlay. Japanese Journal of Plastic & Reconstructive Surgery 2001; 44(1): 21-26 Not a comparative study Unglaub F, Ulrich D, Pallua N. Reconstructive surgery using an artificial dermis (Integra((R))): Results with 19 grafts. Zentralblatt fur Chirurgie 2005; 130(2): 157-161 Not a comparative study van Zuijlen PPM, van Trier AJM, Vloemans JFPM, Groenevelt F, Kreis RW, Middelkoop E. Graft survival and effectiveness of dermal substitution in burns and reconstructive surgery in a one-stage grafting model. Plastic and Reconstructive Surgery 2000; 106(3): 615-623 Non-randomised comparative study van Zuijlen PPM, Vloemans JFP, van Trier AJM, Suijker MH, van Unen E, Groenevelt F, Kreis RW, Middelkoop E. Dermal substitution in acute burns and reconstructive surgery: A subjective and objective long-term followup. Plastic and Reconstructive Surgery 2001; 108(7): 1938-1946 Non-randomised comparative study Vloemans AF, Soesman AM, Suijker M, Kreis RW, Middelkoop E. A randomised clinical trial comparing a hydrocolloid-derived dressing and glycerol preserved allograft skin in the management of partial thickness burns. Burns 2003; 29: 702-710 No comparison with a bioengineered skin substitute Wang NZ, Reynolds PS, Coumbe A, Frame JD. Microskin grafting with Biobrane: A new application. European Journal of Plastic Surgery 1995; 18(4): 157-161 Not a comparative study Weber RS, Hankins P, Limitone E, Callender D, Frankenthaler RM, Wolf P, Goepfert H. Split-thickness skin graft donor site management. A randomized prospective trial comparing a hydrophilic polyurethane absorbent foam dressing with a petrolatum gauze dressing. Archives of Otolaryngology -- Head & Neck Surgery 1995; 121(10): 1145-1149 Not on burns Wisser D and Steffes J. Skin replacement with a collagen based dermal substitute, autologous keratinocytes and fibroblasts in burn trauma. Burns 2003; 29(4): 375-380 Not a comparative study Yamaguchi Y, Hosokawa K, Sumikawa Y, Kakibuchi M, Yoshikawa K. The use of autologous and bioengineered epidermis to control fibrosis and improve cosmesis. Wounds-A Compendium of Clinical Research and Practice 2000; 12(3): 68-75 Not a comparative study 74 APPENDIX C – METHODOLOGICAL ASSESSMENT AND STUDY DESIGN TABLES Appendix C – Methodological Assessment and Study Design Tables Appendix C.1 Study design tables – Biobrane® for the management of burns Authors Intervention Study Design Study Population Inclusion/Exclusion Criteria Lal 2000 Biobrane® vs. Silver Sulfadiazine Randomised controlled trial. Paediatric patients with superficial partial thickness scald burns. Initial Preparation: Wounds were debrided to remove overlying epidermis using sharp and blunt dissection, and cleaned with Betadine® followed by copious irrigation. Randomisation was achieved by a computer-generated randomisation table. No blinding. Pain Medication: Intravenous morphine every 2-4 hrs as needed to control pain. Level of Evidence: II Biobrane® Layers of Dressing: ▪ Biobrane® sheets (hands were covered with Biobrane® gloves and maintained in an elevated position) ▪ Fine mesh gauze impregnated with 2% polymyxin B-bacitracin ointment and 1% nystatin ointment ▪ Dry cotton dressings ▪ Elastic bandages Fixation: Stapled to the skin or wrapped circumferentially around the extremities and the torso Dressing Changes: Dressing remained intact for 12-24 hrs, then if Biobrane® was adherent without signs of underlying infection, wounds were covered with dry gauze once a day or left open at the attending surgeon’s discretion. Follow-up: Not stated. Mean Age: (years) Biobrane 2.8 (SE: 0.5) (n=34) SSD 3.4 (SE: 0.6) (n=45) Inclusion criteria: ▪ superficial 2nd degree hot fluid scald burns that were 5-25% TBSA ▪ within 48 hrs of injury ▪ did not appear to need grafting ▪ showed no initial signs of cellulitis. Lost to Follow-up: 10/89 (11%) Biobrane 7/41 (17%) SSD 3/48 (6%) All 10 patients were excluded from analysis. Gender Mix: (M/F) Biobrane 19/15 (n=34) SSD 30/15 (n=45) Location Department of Surgery, University of Texas Medical Branch, and Shriners Burns Hospital, Galveston, Texas, USA Silver Sulfadiazine (SSD) Layers of Dressing: ▪ SSD impregnated fine mesh gauze ▪ Dry cotton dressings ▪ Elastic bandages Fixation: NA Dressing Changes: Twice a day Definition of Success Full wound healing. When Biobrane® was adherent without signs of underlying infection. If Biobrane® did not adhere to the wound surface, it was removed and conservative treatment was implemented. Study Period: 1994 to 1999. Operator Details: While in hospital, dressing changes were done by hospital staff. Upon discharge, parents were given instructions for its application. Outcome Measures: ▪ Length of hospital stay ▪ Number of days for wound to heal ▪ Need for oral antibiotics after acute hospital discharge ▪ Hospital readmission for infection/sepsis ▪ Need for skin grafting Sample Size: 89 patients Biobrane 41 patients SSD 48 patients Mean Total Burn Surface Area (TBSA)*: (%) Biobrane 11.8 (SE: 1.1) (n=34) SSD 11.5 (SE: 0.9) (n=45) *excludes head and neck Mechanism of Burn Injury: Not stated. Burn Location: (%) Biobrane Extremity 19 Trunk 14 Extremity + Trunk 66 SSD 24 7 69 Exclusion criteria: ▪ burns <5% TBSA or >25% TBSA ▪ later than 48 hrs from injury ▪ 3rd degree burns in addition to 2nd degree injuries ▪ burned by grease. 77 78 Appendix C.1 Study design tables – Biobrane® for the management of burns (continued) Authors Intervention Study Design Study Population Barret 2000 Biobrane® vs. Silver Sulfadiazine Randomised controlled trial. Paediatric patients with partial thickness burns. Initial Preparation: All patients were sedated with ketamine and received superficial debridement of blisters and debris. Method of allocation not stated. No blinding. Sample Size: 20 patients Biobrane 10 patients SSD 10 patients Location Shriners Burns Hospital and the University of Texas Medical Branch, Galveston, Texas, USA Pain Medication: For procedural pain - 0.3mg/kg/dose morphine by mouth; for background pain – 15mg/kg/dose acetaminophen by mouth every 4 hrs. Lorazepam 0.03mg/kg/dose by mouth every 4 hrs was given for anxiety. Biobrane® Layers of Dressing: ▪ Biobrane® was applied to open wound Fixation: Not stated Dressing Changes: Biobrane® was left intact until wounds were considered to be healed. Silver Sulfadiazine (SSD) Layers of Dressing: Not stated Fixation: NA Dressing Changes: Twice daily Definition of Success Wounds were considered healed when all areas affected in the initial injury were closed. Level of Evidence: II Follow-up: (days to complete wound healing) Biobrane mean 9.7 (SE: 0.7) SSD mean 16.1 (SE: 0.6) Lost to Follow-up: 0 Study Period: Not stated. Operator Details: Wounds were inspected within 24 hrs and patients were discharged home when parents were ready to assume wound care. Outcome Measures: ▪ Pain ▪ Pain medication requirements ▪ Infection ▪ Healing time ▪ Length of stay in hospital Mean Age: (years) Biobrane 3.1 (SE: 0.5) SSD 3.7 (SE: 0.6) Gender Mix: (M/F) Biobrane 7/3 SSD 8/2 Mean Total Burn Surface Area (TBSA): (%) Biobrane 8.9 (SE: 4.9) SSD 7.8 (SE: 0.9) Mechanism of Burn Injury: (Flame/Scalds) Biobrane 2/8 SSD 3/7 Inclusion/Exclusion Criteria Inclusion criteria: ▪ 0-17 years old ▪ thermal flame or scald injury ▪ TBSA burned between 2 and 29% ▪ admitted within 24 hrs after the injury ▪ clean non-infected wound as diagnosed by the attending physician. Exclusion criteria: ▪ >17 years old ▪ causes other than thermal flame or scald injuries ▪ full thickness burns ▪ admission time >24 hrs after the injury ▪ wounds noted to be contaminated or infected. Appendix C.1 Study design tables – Biobrane® for the management of burns (continued) Authors Intervention Study Design Study Population Inclusion/Exclusion Criteria Kumar 2004 TransCyte® vs. Biobrane® vs. Silver Sulfadiazine Randomised controlled trial. Paediatric patients with partial thickness burns. Initial Preparation: Wounds were debrided within 24 hrs of burn injury using appropriate topical and systemic analgesia. Randomisation by lottery. No blinding. Pain Medication: Narcotic analgesia during dressing changes. Follow-up: mean 11 days TransCyte® Layers of Dressing: ▪ TransCyte® (thawed at 37°C prior to application) ▪ A dry bulky dressing (Melolin; Smith & Nephew) ▪ Compression dressing or elastic wrap to maintain contact with the wound until the product was adherent Fixation: Sterile adhesive (Hypafix; Smith & Nephew) or staples to form a cuff if the wound site was on a limb Dressing Changes: After 24 hrs, if not adherent the outer dressings were replaced for a further 24 hrs and re-evaluated at that time. Lost to Follow-up: 0 Inclusion criteria: ▪ wounds deemed to be partial thickness in depth ▪ laser Doppler criteria of perfusion values of between 32 and 65% ▪ equivalent flux values of between 250 and 600 random units. Location Stuart Pegg Burns Unit, Royal Children’s Hospital, Brisbane, Queensland, Australia Biobrane® Layers of Dressing: ▪ Biobrane® ▪ A dry bulky dressing (Melolin; Smith & Nephew) ▪ Compression dressing or elastic wrap to maintain contact with the wound until the product was adherent Fixation: Sterile adhesive (Hypafix; Smith & Nephew) or staples to form a cuff if the wound site was on a limb Dressing Changes: After 24 hrs, if not adherent the outer dressings were replaced for a further 24 hrs and re-evaluated at that time. Silver Sulfadiazine (SSD) Layers of Dressing: Once the wound area was clean with no eschar, SSD use was stopped and the wound covered with a hydrocolloid dressing (Duoderm Thin; Smith & Nephew). Fixation: NA Dressing Changes: Daily Definition of Success The product provided wound coverage until re-epithelialisation. Level of Evidence: II Study Period: June 2000 to June 2001. Operator Details: 2 independent observers assessed burn depth and percentage of closure. Outcome Measures: ▪ Time to re-epithelialisation ▪ Number of wounds requiring autografting ▪ Number of dressing changes and local wound care required (e.g. medical intervention, pain medication) ▪ Burn depth (laser Doppler imaging system) ▪ Percentage of closure (rated by visual estimation) Sample Size: 33 patients (58 wounds) TransCyte 20 wounds Biobrane 17 wounds SSD 21 wounds Mean Age: (years) 3.60 Gender Mix: (M/F) Not stated. Mean Total Burn Surface Area (TBSA): (%) 5 Mechanism of Burn Injury: “predominantly via hot water scalds” Exclusion criteria: ▪ burn injury occurred >24 hrs prior to commencement of treatment ▪ wounds identified as study areas were full thickness in depth ▪ wounds to be studied exhibited clinical signs of infection. 79 80 Appendix C.1 Study design tables – Biobrane® for the management of burns (continued) Authors Intervention Study Design Study Population Inclusion/Exclusion Criteria Gerding 1990 Biobrane® vs. Silver Sulfadiazine Randomised controlled trial. Patients with partial thickness burns. Initial Preparation: All wounds were completely debrided of blisters and loose tissue and cleansed with sterile saline before randomisation. Randomisation was achieved by computergenerated codes within sealed, numbered envelopes that were opened in sequential fashion. No blinding of patients, physicians or assessors. Sample Size: 64 patients were enrolled. Data available on 52 patients* (56 wounds) Biobrane 26 patients (30 wounds) SSD 26 patients (26 wounds) Inclusion criteria: ▪ >2 months old ▪ not pregnant ▪ fresh partial thickness wounds ▪ no history of sulfa sensitivity ▪ wounds with a moist, sensate surface and prompt capillary refill. Location Departments of Surgery and Emergency Medicine, MetroHealth Medical Centre, Case Western Reserve University, Cleveland, Ohio, USA Pain Medication: Adult patients were given prescriptions for acetaminophen with codeine. Children were treated with acetaminophen alone. Biobrane® Layers of Dressing: ▪ Porous (green label) material was applied under moderate tension in a wrinklefree manner to the wound ▪ Dry gauze ▪ Elastic wraps Fixation: Steri-Strips® or 1-inch paper tape Dressing Changes: Wounds were inspected after 24 to 36 hrs. Non-adherent Biobrane® was aspirated or reapplied at the 1st dressing change if the wound appeared clean, free of eschar, and uninfected. The fabric was removed and not replaced if the Biobrane® was discovered to be loose or have fluid collections on subsequent inspections. Silver Sulfadiazine (SSD) Layers of Dressing: ▪ Dry gauze ▪ Elastic wraps Fixation: NA Dressing Changes: Patients were instructed to change their dressings twice daily, to remove all old cream, and to apply a thick coat of cream with each new application. Definition of Success Healing time was defined as the time required to fully re-epithelialise the burn surface. Infected and skin-grafted wounds were considered failures of therapy and excluded from healing time analysis. Level of Evidence: II Follow-up: 44 weeks. Lost to Follow-up: 12/64 (19%) Biobrane 2/12 (17%) lost to follow-up 4/12 (33%) removed due to protocol violations by non-investigators 1/12 (8%) excluded as patient was suffering from scarlet fever SSD 4/12 (33%) lost to follow-up 1/12 (8%) removed due to protocol violations by non-investigators Study Period: Not stated. Operator Details: Not stated. Outcome Measures: ▪ Healing time ▪ Wound infection ▪ Pain ▪ Compliance with scheduled visits ▪ Costs Wounds were inspected at 24-36 hrs after initiation of therapy. Mean Age: (years) Biobrane 18.3 (SE: 2.6) (range 10 months-55 years) SSD 22.1 (SE: 3.5) (range 8 months-79 years) Gender Mix: (M/F) Biobrane 19/11 SSD 18/8 Mean Total Burn Surface Area (TBSA): (%) Biobrane 2.0 (SE: 0.3) (range 0.5-5.0) SSD 2.4 (SE: 0.5) (range 0.5-10.0) Mechanism of Burn Injury: Aqueous Grease Contact Scald Biobrane 17 9 2 SSD 17 4 3 *data extracted from Figure 1 (appears to be number of wounds not patients). Exclusion criteria: ▪ chemical or electrical burns ▪ grossly contaminated wounds ▪ wounds more than 24 hrs old ▪ wounds treated by any topical agent before presentation to the emergency department. Appendix C.1 Study design tables – Biobrane® for the management of burns (continued) Authors Intervention Study Design Study Population Inclusion/Exclusion Criteria Cassidy 2005 Biobrane® vs. Duoderm® Randomised controlled trial. Initial Preparation: Wounds were debrided before application of coverage material. Method of allocation not stated. Blinding status not stated. Consecutive paediatric patients with superficial or mid-dermal partial thickness burns. Location Pain Medication: No topical or prophylactic antibiotics were utilised. Level of Evidence: II Inclusion criteria: ▪ 3-18 years old ▪ superficial or mid-dermal partial thickness burn <10% TBSA. Department of Pediatric Surgery, The Children’s Mercy Hospital, Kansas City, Missouri, USA Biobrane® Layers of Dressing: ▪ Followed nursing instruction included in the manufacturer guidelines (no other details given). Fixation: Not stated Dressing Changes: Not stated Follow-up: Not stated. Duoderm® Layers of Dressing: ▪ Followed nursing instruction included in the manufacturer guidelines (no other details given). Fixation: Not stated Dressing Changes: Not stated Definition of Success Complete healing was defined as complete re-epithelialisation as assessed by an experienced burn surgeon or nurse. Lost to Follow-up: 0 Study Period: Not stated. Operator Details: Not stated. Outcome Measures: ▪ Time to complete healing ▪ Pain scores (Oucher Score or Visual Analogue Scale) ▪ Institutional cost of materials until healing was complete Sample Size: 72 patients Biobrane 35 patients Duoderm 37 patients Mean Age: (years) Not stated. Gender Mix: (M/F) 38/34 Mean Total Burn Surface Area (TBSA): (%) Not stated. Mechanism of Burn Injury: Scald – 44 Contact – 24 Flame – 2 Miscellaneous – 2 Exclusion criteria: ▪ Burns involving the face, hands, feet, or perineum. 81 82 Appendix C.2 Study design tables – Biobrane® for the management of donor sites Authors Intervention Study Design Study Population Still 2003 OrCel™ vs. Biobrane® Randomised controlled trial – within-patient comparison. Patients with partial thickness burns. Inclusion criteria: Sample Size: 82 patients ▪ ≥12 months of age ▪ burns involving 10 to 80% Mean Age: (years) 31.7 (range 1-88) ▪ anticipated life expectancy Gender Mix: (M/F) 63/19 Exclusion criteria: Not stated. Pain Medication: Not stated Location Physicians Multispecialty Group, Augusta, Georgia, Division of Plastic Surgery, St. Christopher’s Hospital for Children, Philadelphia, Pennsylvania, University of Oklahoma Health Sciences Centre, Oklahoma City, Oklahoma, Timothy J. Harnar Burn Centre, Texas Tech Medical Centre, Lubbock, Texas, Department of Surgery, Shands Burn Centre, University of Florida Health Sciences Centre, Gainesville, Florida, USA OrCel™ Layers of Dressing: ▪ OrCel™, a porous collagen sponge containing co-cultured allogeneic donor epidermal keratinocytes and dermal fibroblasts from human neonatal foreskin tissue ▪ Non-adherent, moisture-retentive, synthetic materials, such as Adaptic™ or Vaseline™ gauze ▪ Gauze wrap ▪ Ace bandage Fixation: Staples were used at the discretion of the investigator Dressing Changes: ▪ On the 3rd postoperative day, the outer layers were removed. The backing material was left in place and normal saline irrigation to remove any debris was permitted. ▪ Thereafter, removal and replacement of the outer dressing wrap on the OrCel™ was permitted every 48-72 hrs until day 7 when attempts were begun to remove the backing. Biobrane® Layers of Dressing: ▪ Biobrane®, a synthetic wound dressing composed of an ultrathin, semi-permeable silicone membrane and a flexible monofilament nylon fabric ▪ Gauze wraps Fixation: Staples Dressing Changes: Removal of the outer dressing layers was generally performed 24-48 hrs following surgery Definition of Success 100% re-epithelialisation as measured by blinded photographic assessment. Randomisation was based on a computer generated scheme and concealed from the investigator. Blinded assessment of percent re-epithelialisation by 3 independent burn experts. Level of Evidence: II Follow-up: 24 weeks. Total Burn Surface Area (TBSA): 0/82 (0%) had <10% 61/82 (74%) had >20% Lost to Follow-up: 3/82 (4%) died Study Period: Not stated. Operator Details: Not stated. Outcome Measures: ▪ Complete wound closure (planimetry) ▪ Pain (Wong-Baker Faces Pain Rating Scale) ▪ Itching ▪ Blister formation/site breakdown ▪ Wound infection ▪ Scarring (Vancouver Scar Scale and Hamilton Burn-Scar Rating Scale) Mean Surface Area for Donor Sites: (cm2) OrCel 94.4 Biobrane 94.3 Mechanism of Burn Injury: Not stated. Inclusion/Exclusion Criteria TBSA of ≥6 weeks. Appendix C.2 Study design tables – Biobrane® for the management of donor sites (continued) Authors Intervention Study Design Study Population Inclusion/Exclusion Criteria Fratianne 1993 Allogeneic cultured keratinocyte sheets vs. Biobrane® Randomised controlled trial – within-patient comparison. Patients with partial and full thickness burns. Inclusion criteria: Not stated. Location Departments of Surgery, Pathology, and Paediatrics, Case Western Reserve University, MetroHealth Medical Centre, Cleveland, Ohio, USA Initial Preparation: Keratinocyte strains were developed from the foreskins of infants whose mothers tested negative for HIV, Hep B, and Herpes at delivery and at 3 months after delivery. Keratinocytes were grown in the presence of lethally irradiated 3T3 cells. Sample Size: 10 patients Method of allocation not stated. No blinding. Level of Evidence: II Pain Medication: Not stated Follow-up: 23 days. Allogeneic cultured keratinocyte sheets (Keratinocytes) Layers of Dressing: ▪ Keratinocyte sheets on a Vaseline (Chesebrough Ponds, Inc., Greenwich, Conneticut) gauze carrier measuring 4x7cm ▪ Red label Biobrane® Fixation: Staples Dressing Changes: NA Lost to Follow-up: 2/10 (20%) died Biobrane® Layers of Dressing: ▪ Red label Biobrane® Fixation: Staples Dressing Changes: NA Definition of Success Complete healing. Mean Age: (years) 44.3 (range 21-86) Gender Mix: (M/F) 7/3 Mean Total Burn Surface Area (TBSA): (%) 35.8 (range 3-90) Study Period: Not stated. Operator Details: Not stated. Outcome Measures: ▪ Wound healing ▪ Healing time ▪ Histologic examinations (3mm punch biopsies at postop day 7) Mechanism of Burn Injury: Not stated. Exclusion criteria: Not stated. 83 84 Appendix C.3 Study design tables – TransCyte® for the management of burns Authors Intervention Study Design Study Population Noordenbos 1999 TransCyte® vs. Silver Sulfadiazine Randomised controlled trial – within-patient comparison. Patients with partial thickness burns. Pain Medication: Narcotic analgesia was used as required during dressing changes. Location Department of Surgery, University of California, San Diego Medical Centre, California, USA TransCyte® Layers of Dressing: ▪ TransCyte® (human dermal fibroblasts were isolated from newborn foreskins and grown aseptically on the nylon mesh of Biobrane®) Fixation: Sterile adhesive tape strips (Suture Strip Plus, abco Dealers, Nashville, TN) or surgical staples Dressing Changes: After 1 or 2 days, the outer dressings were usually removed and the sites were left open to air. Silver Sulfadiazine (SSD) Layers of Dressing: ▪ Topical therapy with SSD ▪ When the wound was clean of necrotic tissue and debris, a semi-occlusive dressing (Xeroform, Kendall Inc., Mansfield, MA) was used Fixation: NA Dressing Changes: Twice daily Definition of Success Epithelial closure of at least 90% of the study site wound, or the day on which excision and grafting was performed. Method of allocation not stated. No blinding. Level of Evidence: II Follow-up: 12 months. Lost to Follow-up: 3/14 (21%) at 3 and 12 months. 5/14 (36%) at 6 months. Study Period: Not stated. Operator Details: 1 of the clinical research study nurses evaluated scar formation. Outcome Measures: ▪ Number of days until epithelial closure ▪ Wound infection ▪ Scar formation (Vancouver Burn Scale) Sample Size: 14 patients Mean Age: (years) 23.4 [19.4] (range 1.1-52) Gender Mix: (M/F) Not stated. Mean Total Burn Surface Area (TBSA): (%) 13.3 [7.2] (range 4-30) Mean TBSA covered: (%) TransCyte 3.18 [2] (range 1.5-9) SSD 3.66 [3.4] (range 1.5-15) Mechanism of Burn Injury: Not stated. Inclusion/Exclusion Criteria Inclusion criteria: ▪ burns of 2% to 30% TBSA ▪ 1 to 70 years old ▪ 2 comparable-sized wounds judged by the clinicians to be moderate to deep partial thickness in depth. Exclusion criteria: ▪ wounds of the hands, face, buttocks, feet and genitalia ▪ >24 hrs after injury. Appendix C.3 Study design tables – TransCyte® for the management of burns (continued) Authors Intervention Study Design Study Population Inclusion/Exclusion Criteria Demling and DeSanti 1999 TransCyte® vs. Bacitracin Randomised controlled trial. Consecutive patients with mid-partial thickness burns to the face. Patients were initially categorised into 2 groups: - major burns: require at least 7 days hospitalisation - minor burns: have the potential for outpatient care. Method of allocation not stated. Blinding status not stated. Inclusion criteria: ▪ >18 years of age ▪ partial thickness (middermal) burns of at least 50% of the facial surface. (possible patient overlap with Demling and DeSanti 2002) Location Trauma and Burn Centre, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA Initial Preparation: All patients underwent complete debridement of non-viable epidermis and upper dermis using blunt debridement (moist gauze) using systemic and topical analgesia. No tangential excision was performed. Pain Medication: For minor burns – TransCyte® All required non-steroidal anti-inflammatory agent for wound care & in between care Bacitracin 100% required oral narcotics for wound care & 75% required oral narcotics for in between care TransCyte® Layers of Dressing: ▪ TransCyte® sheets were thawed and placed on the wound ▪ A fluffed soft gauze was then applied to fit the facial contours for 3-4 hrs after which the gauze was removed and the wound treated open Fixation: Not stated Dressing Changes: Not stated Bacitracin Layers of Dressing: ▪ Bacitracin ointment was used for the mid-dermal areas ▪ SSD was used only on deeper areas for 1-2 days, before initiation of bacitracin treatment Fixation: NA Dressing Changes: Wound was cleansed and antibiotics re-applied 2-3 times a day depending on the degree of exudate build-up Definition of Success Healing time was defined as the point in time when 90% of the wound was re-epithelialised. Level of Evidence: II Follow-up: ~18 days. Lost to Follow-up: 0 Study Period: Not stated. Operator Details: Not stated. Outcome Measures: ▪ Daily wound care time ▪ Pain between and during wound care ▪ Healing time ▪ Discharge time ▪ Wound infection ▪ Wound conversion Sample Size: 21 patients TransCyte 10 patients (5 major, 5 minor) Bacitracin 11 patients (6 major, 5 minor) Mean Age: (years) Major burns – TransCyte 44 [10] Bacitracin 40 [8] Minor burns – TransCyte 31 [8] Bacitracin 29 [7] Gender Mix: (M/F) Not stated. Mean Total Burn Surface Area (TBSA): (%) Major burns – TransCyte 32 [9] Bacitracin 30 [8] Minor burns – TransCyte 10 [3] Bacitracin 7 [2] Mechanism of Burn Injury: Not stated. Exclusion criteria: Not stated. 85 86 Appendix C.3 Study design tables – TransCyte® for the management of burns (continued) Authors Intervention Study Design Study Population Inclusion/Exclusion Criteria Demling and DeSanti 2002 TransCyte® vs. Topical Antibiotics Randomised controlled trial. Patients with mid-partial thickness burns to the face. Inclusion criteria: Not stated Initial Preparation: For wounds receiving Transcyte®, the burn wound was initially debrided under conscious sedation. Method of allocation not stated. The burn centre nurse coordinator and nurse research assistant collected the data. Blinding status not stated. Sample Size: 34 patients TransCyte 16 patients Antibiotics 18 patients (possible patient overlap with Demling and DeSanti 1999) Location Pain Medication: Increased narcotics and sedation were needed in the Topical Antibiotics group. Burn Centre, Brigham & Women’s Hospital, Boston, Massachusetts, USA TransCyte® Layers of Dressing: ▪ TransCyte® (thawed) ▪ Light gauze dressing (removed after 12-24 hrs) Fixation: Not stated Dressing Changes: Not stated Topical Antibiotics Layers of Dressing: ▪ Antibiotic ointment was used for facial burns ▪ SSD was used on burns to the ears Fixation: NA Dressing Changes: Twice daily Definition of Success Time to 95% re-epithelialisation. Level of Evidence: II Mean Age: (years) TransCyte 39 [9] Antibiotics 40 [8] Follow-up: ~19 days. Lost to Follow-up: 0 Study Period: Not stated Operator Details: Not stated Outcome Measures: ▪ Pain (0-10 pain scale, 0=no pain; 10=worst pain) ▪ Healing time ▪ Wound infection ▪ Nursing time ▪ Cost Gender Mix: (M/F) Not stated Mean Total Burn Surface Area (TBSA): (%) TransCyte 24 [8] Antibiotics 21 [9] % Full Thickness: TransCyte 12 [7] Antibiotics 10 [6] Mechanism of Burn Injury: (Flame/Scald) TransCyte 11/5 Antibiotics 12/6 Exclusion criteria: Not stated Appendix C.4 Study design tables – Dermagraft® for the management of burns Authors Intervention Study Design Study Population Inclusion/Exclusion Criteria Hansbrough 1997 Dermagraft® vs. Allograft Randomised controlled trial – within-patient comparison. Patients with partial and full thickness burns. Inclusion criteria: ▪ burn wounds requiring surgical excision ▪ temporary wound closure was clinically necessary. Location Department of Surgery, the University of California, San Diego Medical Centre, The US Army Institute of Surgical Research, Fort Sam Houston, the University of Iowa Burn Treatment Centre, Iowa City, and Advanced Tissue Sciences, Inc., La Jolla, California, USA Sample Size: 10 patients (3 sites per patient) Initial Preparation: Wound haemostasis was achieved with topical thrombinepinephrine solution and electrocoagulation. Method of allocation not stated. Blinding status not stated. Pain Medication: Not stated Level of Evidence: II Dermagraft® Layers of Dressing: ▪ Dermagraft® Red (cryopreserved by a method that maintains most of the metabolic activity of the cultured fibroblasts) OR ▪ Dermagraft® Blue (frozen by a method that does not maintain metabolic activity of the product) Fixation: Staples Dressing Changes: Not stated Follow-up: 14 days. Allograft Layers of Dressing: ▪ Cryopreserved human cadaver allograft skin (obtained from tissue banks) Fixation: Staples Dressing Changes: Not stated When clinically indicated, Dermagraft® and allograft dressings were removed. Autograft skin was harvested from appropriate donor sites, and meshed at a ratio of either 1.5:1 or 2:1. Definition of Success Autograft take defined as the percentage of autograft that was present, adherent, and vascularised. Lost to Follow-up: 3/10 (30%) Study Period: Not stated. Operator Details: All sites were excised to similar depth in individual patients (subcutaneous fat, fascia, or deep dermis/fat). Outcome Measures: ▪ Adherence of wound coverings ▪ Fluid accumulation under the temporary covering ▪ Quantity and quality of the drainage ▪ Colour of the wound bed ▪ Ease of removal of the temporary covering ▪ Vascularity of the wound before autografting ▪ Autograft take ▪ Wound closure ▪ Investigator’s overall assessment Mean Age: (years) 33.5 (range 7-62) Gender Mix: (M/F) Not stated. Mean Total Burn Surface Area (TBSA): (%) Partial thickness burn: 20.3 (range 8-56) Full thickness burn: 19.6 (range 0-45) Mechanism of Burn Injury: Not stated. Location of Study Wound Sites: Legs (n=4) Arms (n=2) Flank (n=1) Chest/abdomen (n=2) Back (n=1) Exclusion criteria: Not stated. 87 88 Appendix C.4 Study design tables – Dermagraft® for the management of burns (continued) Authors Intervention Study Design Study Population Inclusion/Exclusion Criteria Purdue 1997 Dermagraft® vs. Allograft Randomised controlled trial – within-patient comparison. Patients with full thickness burns on adjacent sites. Inclusion criteria: Not stated. Location University of Texas Southwestern Medical Centre, Dallas, Texas, Augusta Regional Medical Centre, Augusta, Georgia, Shriners Burn Institute, Galveston, Texas, The Western Pennsylvania Hospital, Pittsburgh, Pennsylvania, Maricopa Medical Centre, Phoenix, Arizona, UCSD Medical Centre, San Diego, California, University of Tennessee, Medical Group, Memphis, Tennessee, University of Virginia Health Sciences Centre, Charlottesville, Virginia, University of Iowa Burn Treatment Centre, Iowa City, Iowa, Hennepin County Medical Centre, Minneapolis, Minnesota, UC Davis Medical Centre, Sacramento, California, St Paul-Ramsey Medical Centre, St Paul, Minnesota, and Advanced Tissue Sciences, Inc., La Jolla, California, USA Initial Preparation: Wounds were excised within 2 weeks of the burn. Both sites were excised in the same manner to viable deep dermis, subcutaneous fat, fascia, or muscle. Pain Medication: Not stated Dermagraft® Layers of Dressing: ▪ Dermagraft® (thawed in its cassette immediately before use and washed 4 times with normal saline solution) ▪ When the wound was clinically ready, Dermagraft® was removed and autografts were applied Fixation: Staples Dressing Changes: Not stated Allograft Layers of Dressing: ▪ Allograft skin (obtained from each centre’s usual tissue bank and prepared in the manner typical for that centre) ▪ When the wound was clinically ready, the allograft was removed and autografts were applied Fixation: Staples Dressing Changes: Not stated Definition of Success Percent autograft take. Sample Size: 66 patients. Method of allocation not stated. Only wound biopsy specimens were analysed in a blind manner. Level of Evidence: II Mean Age: (years) 36.3 [22.4] (median 32.5; range 2-89) Gender Mix: (M/F) 45/21 Follow-up: 28 days. Lost to Follow-up: 20/66 (30%) were not available for percent autograft take evaluation. 8/66 (12%) died 2/66 (3%) had treatment other than skin grafts 7/66 (11%) had temporary covering deviations 3/66 (4.5%) had premature removal of temporary coverings or autograft. Study Period: Not stated. Operator Details: Not stated. Outcome Measures: ▪ Percent autograft take ▪ Percent adherence and fluid accumulation ▪ Investigators’ global assessments ▪ Method and ease of removal ▪ Bleeding ▪ Percent wound closure ▪ Rejection/loss of allograft and reapplications ▪ Safety assessments such as wound infections, intercurrent events, and adverse device effects ▪ Immunological safety (wound biopsy specimens) Mean Total Burn Surface Area (TBSA): (%) 44.3 [20.0] (median 42.3; range 4-95) Full thickness burn: 27.8 [21.3] (median 24.8; range 0-95) Mechanism of Burn Injury: Not stated. Exclusion criteria: Not stated. Appendix C.4 Study design tables – Dermagraft® for the management of burns (continued) Authors Intervention Study Design Study Population Inclusion/Exclusion Criteria Spielvogel 1997 Dermagraft® vs. Allograft Randomised controlled trial – this was a histologic study. Sample Size: 65 patients. Dermagraft 51 histologic specimens Allograft 51 skin allograft control specimens Inclusion criteria: Not stated. Biopsies were done at the time of removal of the temporary covering. Location Pain Medication: Not stated Allegheny University of the Health Sciences, Philadelphia, Pennsylvania, USA Dermagraft® Layers of Dressing: Not stated Fixation: Not stated Dressing Changes: Not stated Method of allocation not stated. The slides were reviewed in a blind fashion (blind regarding the clinical results, not in terms of not being able to distinguish between control and study specimens). Definition of Success Not stated. Gender Mix: (M/F) Not stated. Level of Evidence: II Follow-up: Not stated. Allograft Layers of Dressing: Not stated Fixation: Not stated Dressing Changes: Not stated Mean Age: (years) Not stated. Lost to Follow-up: 0 Study Period: Not stated. Operator Details: Full thickness specimens were obtained by excision biopsy through Dermagraft® or allograft into the wound bed. Outcome Measures: ▪ Histologic examinations (specimens were reviewed for technical quality, consistency of wound bed, and description of covering, including its interface with the wound bed) Mean Total Burn Surface Area (TBSA): (%) Not stated. Mechanism of Burn Injury: Not stated. Exclusion criteria: Not stated. 89 90 Appendix C.5 Study design tables – Integra® for the management of burns Authors Intervention Study Design Study Population Inclusion/Exclusion Criteria Heimbach 1988 Artificial Dermis vs. Biological Skin Replacement (several types) Randomised controlled trial – within-patient comparison. Sample Size: 149 patients. Complete data available for 106 patients (136 wounds). Pain Medication: Not stated Method of allocation not stated. Blinding status not stated. Age: 27/106 (25%) patients were <15 years 59/106 (56%) patients were 15-60 years 20/106 (19%) patients were >60 years Inclusion criteria: ▪ admitted to hospital with extensive flame or scald burns ▪ burns were considered to be life-threatening ▪ burns not likely to heal within 3 weeks ▪ burns were amenable to early excision and grafting ▪ initial excision within 7 days after burn. Location University of Washington, Seattle, Washington, University of South Alabama, Mobile, Alabama, Harvard University, Cambridge, Massachusetts, University of Iowa, Iowa City, Iowa, University of Texas at Galveston, Galveston, Texas, University of Texas at Dallas, Dallas, Texas, George Washington University, Washington, D.C., US Army Institute of Surgical Research, San Antonio, Texas, St. Paul-Ramsey, University of Cincinnati, Cincinnati, Ohio, and the University of Southern California, Los Angeles, California, USA Artificial Dermis (AD) Layers of Dressing: ▪ Artificial dermis (Marion Laboratories, Kansas City, MO) composed of a porous collagen-chondroitin 6-sulfate fibrillar mat covered with a thin sheet of Silastic ▪ After vascularisation, the artificial dermis was grafted with epidermal grafts taken at the thinnest dermatome setting Fixation: Sutured or stapled Dressing Changes: NA Control Layers of Dressing: ▪ Meshed autograft, or, if donor sites were not available, other conventional temporary wound coverings (allograft, xenograft, or synthetic dressings) ▪ After vascularisation, the materials other than autograft were eventually replaced with autografts Fixation: Not stated Dressing Changes: Not stated Definition of Success Graft take – take of the collagen mat and take of the subsequent epidermal graft. Level of Evidence: II Follow-up: up to 1 year. Lost to Follow-up: 67/149 (45%) Of the initial 149 patients 6/149 (4%) died 37/149 (25%) eliminated from analysis due to protocol violation Of the 106 patients (136 wounds) left 14/106 (13%) died 10/106 (9%) eliminated from analysis due logistic reasons or long-term assessment was not possible. Patients followed-up: 82 patients; 59 patients had 9-month follow-up and 26 patients had 1-year follow-up. Study Period: Not stated. Operator Details: Not stated. Outcome Measures: ▪ Wound infection ▪ Mechanical problems ▪ Time to wound closure ▪ Skin function ▪ Wound appearance ▪ Patient preference Gender Mix: (M/F) 79/27 Mean Total Burn Surface Area (TBSA): (%) 46 [19] Mechanism of Burn Injury: Not stated. Exclusion criteria: Not stated. Appendix C.5 Study design tables – Integra® for the management of burns (continued) Authors Intervention Study Design Study Population Inclusion/Exclusion Criteria Peck 2002 Integra® vs. Biobrane® vs. Allograft Randomised controlled trial – within-patient comparison. Patients with partial and full thickness burns. Method of allocation not stated. Blinding status not stated. Sample Size: 7 patients. Integra vs. Biobrane 4 patients Integra vs. Allograft 3 patients Inclusion criteria: ▪ adult patients aged 18 to 65 years ▪ deep partial or full thickness wounds or both totalling at least 45% TBSA. Location North Carolina Jaycee Burn Centre and the Department of Surgery, University of North Carolina Health Care, Chapel Hill, North Carolina, USA Initial Preparation: Sequential excisions of burn eschar were performed so that all deeply burned skin was removed by 2 weeks after injury. Excision of the burns was performed under general anaesthesia after sterile preparation of the wounds with chlorhexidine gluconate 4% (Calgon Vestal, St Louis, MO). Level of Evidence: II Follow-up: up to 5 months? Mean Age: (years) 41.1 (range 19-54) Pain Medication: Not stated Integra® Layers of Dressing: Phase 1 of the study ▪ Integra® sheets meshed at a 1:1 ratio with a non-crushing mesher (Brennen Medical, Inc., St. Paul, MN) ▪ Mafenide acetate dressings (kept moist postoperatively with application of mafenide acetate 5% solution every 2-6 hours) Phase 2 of the study ▪ Silver-coated burn dressings (applied along the seams of the Integra® sheets) Fixation: Staples and Stretch-Net dressings (DeRoyal, Powell, TN) Dressing Changes: ▪ Mafenide acetate dressings were removed for observation of the grafts and applied fresh daily ▪ Silver-coated burn dressings were moistened with sterile water twice daily Biobrane® Layers of Dressing: Phase 1 of the study ▪ Biobrane® ▪ Mafenide acetate dressings (kept moist postoperatively with application of mafenide acetate 5% solution every 2-6 hours) Fixation: Staples Dressing Changes: These dressings were removed for observation of the grafts and applied fresh daily Lost to Follow-up: 4/7 (57%) 1/7 (14%) patient moved interstate after discharge 3/7 (43%) died. Study Period: Not stated. Operator Details: Treatment sites were inspected daily by the attending, the burn fellow, or the clinical research nurse. Outcome Measures: ▪ Wound closure ▪ Wound infections ▪ Complications Gender Mix: (M/F) Not stated. Mean Total Burn Surface Area (TBSA): (%) 63.1 (range 47-80) Mechanism of Burn Injury: All patients had thermal injuries. 2/7 (29%) also had inhalation injuries. Exclusion criteria: ▪ electrical injuries and severe exfoliating skin disorders ▪ treatment areas were not selected from the following sites: over joints; on the head and neck; on the buttocks, back, and posterior thighs; and on the hands and feet. 91 92 Appendix C.5 Study design tables – Integra® for the management of burns (continued) Authors Intervention Peck 2002 (continued) Allograft Layers of Dressing: Phase 2 of the study ▪ Cadaver homograft (Ohio Valley Tissue and Skin Centre, Cincinnati, OH) meshed at a 1:1 ratio with a non-crushing mesher (Brennen Medical, Inc., St. Paul, MN) ▪ Gauze soaked with silver nitrate 0.25% solution (kept moist every 2-6 hours) Fixation: Dressing Changes: Daily Location North Carolina Jaycee Burn Centre and the Department of Surgery, University of North Carolina Health Care, Chapel Hill, North Carolina, USA Definition of Success Wound closure. Study Design Study Population Inclusion/Exclusion Criteria Appendix C.6 Study design tables – Apligraf® for the management of burns Authors Intervention Study Design Study Population Inclusion/Exclusion Criteria Waymack 2000 Apligraf® + Autograft vs. Autograft + Allograft Randomised controlled trial – within-patient comparison. Patients with partial thickness and full thickness burns. Once all wounds were grafted, bandaging was performed according to standard methodology as determined by the investigator. Method of allocation not stated. Blinding status not stated. Pain Medication: Not stated Follow-up: up to 24 months. Sample Size: 40 patients enrolled. Apligraf 40 patients Autograft 36 patients* Auto + Allo 2 patients* Inclusion criteria: ▪ burns covering at least 2% but not more than 97% TBSA ▪ expected to survive at least 2 years. Apligraf® + Autograft (Apligraf) Initially the experimental arm involved the application of Apligraf® directly onto the excised wound bed. However, significant graft loss occurred with the initial patients, so the protocol was amended to treat patients with Apligraf® applied over meshed autograft. Layers of Dressing: ▪ Meshed (≥2:1), expanded autograft ▪ Meshed (1:1.5), unexpanded Apligraf® Fixation: Not stated Dressing Changes: Not stated Lost to Follow-up: 24/40 (60%) 20/40 (50%) lost to follow-up 2/40 (5%) excluded due to non-compliance 1/40 (2.5%) due to Apligraf® loss 1/40 (2.5%) data not collected after grafting. * A last observation carried forward (LOCF) approach was used for primary statistical analysis, where data from the prior evaluation point was carried forward to estimate missing patient information. Autograft + Allograft Layers of Dressing: ▪ Meshed (≥2:1), expanded autograft alone OR ▪ Meshed (≥2:1), expanded autograft ▪ Meshed (1.5:1), unexpanded allograft Fixation: Not stated Dressing Changes: At each follow-up visit Study Period: Not stated. Location University of Washington Burn Centre, Harborview Medical Centre, Seattle, WA, University of California at San Diego, San Diego, CA, University of South Alabama Burn Centre, Mobile, AL, Massachusetts General Hospital, Boston, MA, Shriners Hospital for Crippled Children, Galveston Unit, Burns Institute, Galveston, TX, USA Definition of Success Wound healed. *Control site grafting information was missing for 2 patients. Level of Evidence: II Patients followed-up: 38 patients at week 1, 36 patients at week 2, 23 patients at month 6, 21 patients at month 12, and 16 patients at month 24. Operator Details: For each patient, autografts were meshed identically for both treatment and control sites. Outcome Measures: ▪ Overall cosmetic appearance ▪ Graft take ▪ Wound closure ▪ Wound exudate ▪ Pigmentation, vascularity, pliability, height, and scarring ▪ Safety (immunological tests, reporting of adverse events) Mean Age: (years) 36.3 (range 3-78) Gender Mix: (M/F) 36/4 Mean Total Burn Surface Area (TBSA): (%) 23.6 (range 5-90) Type of Burn: 33/40 (82.5%) patients had both partial and full thickness burns 6/40 (15%) patients had partial thickness burns only 1/40 (2.5%) patient had full thickness burns only. Mechanism of Burn Injury: (Thermal/Chemical/Both) 38/1/1 Exclusion criteria: ▪ heavily contaminated wounds ▪ known allergy or hypersensitivity to bovine proteins ▪ history of abnormal bleeding ▪ medical conditions that would impair healing ▪ taking medications that would interfere with treatment compliance or the evaluation of the Apligraf® graft. 93 94 Appendix C.7 Study design tables – Autologous cultured skin for the management of burns Authors Intervention Study Design Study Population Inclusion/Exclusion Criteria Boyce 2002 Autologous Epidermal Substitute vs. Autograft Pseudo-randomised controlled trial – withinpatient comparison. Paediatric patients with full thickness burns. (possible patient overlap with Boyce 1995) Initial Preparation: Burn eschar was excised as early as possible. Sites were initially covered with cadaveric allograft or the dermal substitute Integra®. These temporary dressings were removed 1 day before grafting. On the day of grafting, wounds were irrigated with a solution of nutrients and antimicrobials. Wound sites were randomised according to patient enrolment number. No blinding. Sample Size: 45 patients (90 wounds). Inclusion criteria: ▪ >50% TBSA full thickness cutaneous burns. Level of Evidence: III-1 Mean Age: (years) 10.6 (SE: 1.6) for all patients. 8.0 (SE: 1.5) for last 12 patients. Location Shriners Hospitals for Children in Cincinnati, Ohio, and Sacramento, California, and the Department of Surgery, University of Cincinnati, Cincinnati, Ohio, USA Pain Medication: Not stated Follow-up: up to 1 year. Autologous Epidermal Substitute (AES) Layers of Dressing: ▪ AES ▪ Fine mesh gauze ▪ Bulky gauze containing perforated red rubber catheters ▪ Spandex stretched to apply gentle pressure and to immobilise the grafted sites ▪ After days 5-7, AES was treated with a Neosporin/Bactroban/Nystatin ointment and covered with a dry bulky gauze Fixation: Staples and N-terface (Winfield Laboratories, Richardson, TX) Dressing Changes: on days 2, 4, 5, and daily thereafter until day 7 to 9 Lost to Follow-up: 0 Autograft Layers of Dressing: ▪ Expanded split thickness autografts, meshed at ratios between 1:1.5 and 1:4 ▪ Fine mesh gauze ▪ Bulky gauze containing perforated red rubber catheters (autograft was routinely irrigated for 5 days with alternating solutions of 5% (w/v) mafenide acetate in water and neomycin/polymyxin B in saline) ▪ Spandex stretched to apply gentle pressure and to immobilise the grafted sites ▪ On day 5 staples were removed, irrigations were discontinued, and dry dressings (consisting of Adaptic™ coated with silver sulfadiazine/bacitracin/nystatin ointment) were applied Fixation: Staples Dressing Changes: on day 2 and 5 Definition of Success Graft take. Study Period: April 1990 to July 1999. Last 12/45 (27%) patients were enrolled between April 1998 and July 1999. Operator Details: Not stated. Outcome Measures: ▪ All patients were assessed by ordinal scoring (0, worst; 10, normal) for erythema, pliability, raised scar, epithelial blistering, pigmentation, and surface texture For the last 12 patients only: ▪ Percentage of engraftment ▪ Ratio of closed wound:donor skin areas ▪ Percentage of TBSA closed with dressing Gender Mix: (M/F) 34/11 for all patients. 8/4 for last 12 patients. Mean Total Burn Surface Area (TBSA): (%) 64.6 (SE: 2.0) for all patients. 76.9 (SE: 2.76) for last 12 patients. Mechanism of Burn Injury: Not stated. Exclusion criteria: ▪ burns to joints, hands, or faces. Appendix C.7 Study design tables – Autologous cultured skin for the management of burns (continued) Authors Intervention Study Design Study Population Inclusion/Exclusion Criteria Boyce 1995 Autologous Epidermal Substitute vs. Autograft Randomised controlled trial – within-patient comparison. Patients with full thickness burns. (possible patient overlap with Boyce 2002) Initial Preparation: One day before skin grafting, eschar was excised to viable tissue that most frequently was subcutaneous fat. Excised wounds were irrigated overnight in a solution of 5% (w/v) mafenide acetate, and grafted the following day. On the day of grafting, excised wounds were irrigated thoroughly with saline to reduce the residual concentration of mafenide acetate. Inclusion criteria: ▪ required skin grafting at least 3 weeks after hospital admission ▪ >50% TBSA. Location Shriners Burns Institute and the Department of Surgery, University of Cincinnati, Cincinnati, Ohio, USA Sample Size: 17 patients (34 wounds). Wound sites were randomised according to enrolment number by a computer-generated schedule. No blinding. Level of Evidence: II Pain Medication: Not stated Follow-up: up to 1 year. Autologous Epidermal Substitute (AES) Layers of Dressing: ▪ AES consisting of collagen-glycosaminoglycan substrates populated with autologous fibroblasts and keratinocytes ▪ Polypropylene mesh (N-Terface, Winfield Laboratories, Richardson, TX) ▪ Fine mesh gauze ▪ Bulky gauze containing red rubber catheters for delivery of irrigation fluids ▪ Spandex fabric that was stretched across the graft site Fixation: Surgical staples Dressing Changes: Not stated Lost to Follow-up: 13/17 (76%) at 1 year. Autograft Layers of Dressing: ▪ Meshed or unmeshed split thickness autograft ▪ Fine mesh gauze ▪ Bulky gauze containing red rubber catheters for delivery of irrigation fluids ▪ Spandex fabric that was stretched across the graft site Fixation: Surgical staples Dressing Changes: Not stated Definition of Success Graft take. Patients followed-up: 17 patients for days 2-14, 11 patients for days 1530, 10 patients for months 1-2, 9 patients for months 3-4, 5 patients for months 5-12, and 4 patients for 1 year and later. Study Period: Not stated. Operator Details: Not stated. Outcome Measures: ▪ Wound exudate ▪ Colouration ▪ Keratinisation ▪ Percent of site covered by graft ▪ Wound qualitative outcomes such as erythema, pigmentation, epidermal blistering, surface texture, skin suppleness and raised scar Mean Age: (years) 12.7 (SE: 3.3) (range 1-50) Gender Mix: (M/F) Not stated. Mean Total Burn Surface Area (TBSA): (%) 68.8 (SE: 2.4) (range 51-87) Mechanism of Burn Injury: Not stated. Exclusion criteria: ▪ burns to joints, hands, or faces. 95 96 Appendix C.8 Study design tables – Allogeneic cultured skin for the management of donor sites Authors Intervention Study Design Study Population Inclusion/Exclusion Criteria Madden 1996 Cultured Epidermal Allograft + Adaptic™ vs. Adaptic™ dressing Randomised controlled trial – within-patient comparison. Patients with partial or full thickness burns. Inclusion criteria: Not stated. Method of CEA preparation: Specimens of split thickness human skin were obtained from the Skin Bank. Human epidermal cells were cultured for at least 20 days before preparation of cultured sheets. A programmable controlled rate freezer was used to freeze the cell sheets. Method of allocation not stated. All wounds and wound margins were visually inspected and scored by blinded observer. Location Departments of Surgery, Otolaryngology, and Pathology, The New York Hospital Cornell Medical Centre, New York, USA Pain Medication: Not stated Cultured Epidermal Allograft (CEA) + Adaptic™ Layers of Dressing: ▪ Sheets were thawed and grafted onto the wound site ▪ Adaptic™ dressing Fixation: Not stated Dressing Changes: NA Adaptic™ dressing Layers of Dressing: ▪ Adaptic™ dressing alone Fixation: NA Dressing Changes: Not stated Definition of Success Complete healing as determined by visual assessment. Level of Evidence: II Follow-up: up to 1 year. Lost to Follow-up: 3/16 (19%) Study Period: Not stated. Operator Details: The same individual created both donor sites to minimise variation in the depth of each wound. Outcome Measures: ▪ Visual and histologic examinations (biopsies taken on postoperative day 7) ▪ Scarring (Vancouver Scale Scar assessments) ▪ Pain assessments Sample Size: 15 patients (16 paired donor sites at mirror image locations) Mean Age: (years) 43.7 (SE: 2.5) (range 21-72) Gender Mix: (M/F) 7/8 Mean Total Burn Surface Area (TBSA): (%) 21.8 (SE: 5.0) (range 3.5-49) Mechanism of Burn Injury: (Flame/Scalds/Chemical) 9/6/1 Exclusion criteria: Not stated. Appendix C.8 Study design tables – Allogeneic cultured skin for the management of donor sites (continued) Authors Intervention Study Design Study Population Inclusion/Exclusion Criteria Duinslaeger 1997 Allogeneic Cultured Keratinocytes vs. OpSite® dressing Randomised controlled trial – within-patient comparison. Sample Size: 15 patients (30 legs) Inclusion criteria: Not stated. Pain Medication: Not stated Location Burn Centre Brussels and Military Hospital, Brussels, and Innogenetics, Ghent, Belgium Allogeneic Cultured Keratinocytes Layers of Dressing: ▪ Allogeneic cultures (6 patients received fresh cultured sheets and 9 patients received cryopreserved cultured sheets) ▪ Paraffin bandage (Jelonet; Smith & Nephew) ▪ Velpeau bandages Fixation: NA Dressing Changes: NA OpSite® dressing Layers of Dressing: ▪ OpSite® dressing (Smith & Nephew, York, UK) ▪ Cotton Velpeau bandages Fixation: NA Dressing Changes: Not stated Definition of Success Wound closure (re-epithelialisation) as determined by visual estimation. Method of allocation not stated. An independent experienced evaluator (biologist) blinded to the treatment. Level of Evidence: II Follow-up: 8-23 months. Lost to Follow-up: 0 Study Period: Not stated. Operator Details: All donor sites were taken by the same surgeon, using the same dermatome, and preoperative treatment was similar on both legs. Outcome Measures: ▪ Rate of re-epithelialisation ▪ Wound healing time ▪ Pain ▪ Complications ▪ Cosmesis Mean Age: (years) 42.2 (range 2-78) Gender Mix: (M/F) 5/10 Mean Total Burn Surface Area (TBSA): (%) 21 (range 6-95) Mechanism of Burn Injury: (Flame/Scalds) 10/5 Depth of Excision on Donor Site: 0.3 mm Exclusion criteria: Not stated. 97 APPENDIX D – MEAN TOTAL BURN SURFACE AREA Appendix D – Mean Total Burn Surface Area for Included Studies Study Intervention Mean total burn surface area (%)* Mechanism of injury Lal 1999 Biobrane Silver sulfadiazine Biobrane 11.8 (SE: 1.1) (34/41 patients) SSD 11.5 (SE: 0.9) (45/48 patients) NS Barret 2000 Biobrane Silver sulfadiazine Biobrane 8.9 (SE: 4.9 SSD 7.8 (SE: 0.9) Flame / scalds Kumar 2004 Biobrane TransCyte Silver sulfadiazine 5 Scalds Gerding 1990 Biobrane Silver sulfadiazine Biobrane 2.0 (SE: 0.3) (range 0.5-5.0) SSD 2.4 (SE: 0.5) (range 0.5-10.0) Scalds / grease / contact / other Cassidy 2005 Biobrane Duoderm NS Scalds / contact / flame / miscellaneous BIOBRANE For the management of burns For the management of donor sites Still 2003 OrCel Biborane 21/82 (26%) had 10-20% 61/82 (74%) had >20% NS Fratianne 1993 Allogeneic cultured keratinocyte sheets Biobrane 35.8 (range 3-90) NS TransCyte Silver sulfadiazine 13.3 [7.2] (range 4-30) % TBSA covered Transcyte 3.18 [2] (range 1.5-9) SSD 3.66 [3.4] (range 1.5-15) NS TRANSCYTE For the management of burns Noordenbos 1999 Table continued over … 99 100 Appendix D: Mean total burn surface area for included studies (continued) Study Intervention Mean total burn surface area (%) Mechanism of injury Demling & DeSanti 1999 TransCyte Bacitracin ointment Major burns – Transcyte 32 [9] Bacitracin 30 [8] Minor burns – Transcyte 10 [3] Bacitracin 7 [2] NS Demling & DeSanti 2002 TransCyte Antibiotic ointments & creams Transcyte 24 [8] Antibiotics 21 [9] Flame / scalds Hansbrough 1997 Dermagraft Allograft Partial thickness burn: 20.3 (range 8-56) Full thickness burn: 19.6 (range 0-45) NS Purdue 1997 Dermagraft Allograft 44.3 [20.0] (median 42.3; range 4-95) Full thickness burn: 27.8 [21.3] (median 24.8; range 095) NS Spielvogel 1997 (histologic study) Dermagraft Allograft NS NS Heimbach 1988 Artificial dermis Auto-, allo- or xenograft 46 [19] NS Peck 2002 Integra Biobrane Allograft 63.1 (range 47-80) Thermal / inhalation DERMAGRAFT For the management of burns INTEGRA For the management of burns Table continued over … Appendix D: Mean total burn surface area for included studies (continued) Study Intervention Mean total burn surface area (%) Mechanism of injury Apligraf + Autograft Autograft 23.6 (range 5-90) Thermal / chemical / both Boyce 2002 Autologous epidermal substitute Autograft 64.6 (SE: 2.0) for all patients 76.9 (SE: 2.76) for last 12 patients NS Boyce 1995 Autologous epidermal substitute Autograft 68.8 (SE: 2.4) (range 51-87) NS APLIGRAF For the management of burns Waymack 2000 AUTOLOGOUS CULTURED SKIN For the management of burns ALLOGENEIC CULTURED SKIN For the management of donor sites Madden 1996 Cultured epidermal allograft + Adaptic Adaptic dressing 21.8 (SE: 5.0) (range 3.5-49) Flame / scalds / chemicals Duinslaeger 1997 Allogeneic cultured keratinocyte sheets OpSite dressing 21 (range 6-95) Flame / scalds * mean TBSA was reported across all groups unless stated otherwise. 101