Download Soft Tissue Coverage in Abdominal Wall Reconstruction

Soft Tissue Coverage in
A b d o m i n a l Wal l R e c o n s t r u c t i o n
Donald P. Baumann,
MD,
Charles E. Butler,
MD*
KEYWORDS
Abdominal wall reconstruction Hernia Surgical mesh
Reconstructive surgical procedures Surgical flaps
KEY POINTS
Soft tissue reconstruction in the abdominal wall requires an algorithmic anatomic
approach based on defect location.
The decision to select a locoregional flap or a free flap is determined by defect surface
area, local donor flap options, and availability of recipient vessels.
Patient systemic comorbidities, locoregional wound conditions, and the possibility of
early/late reoperation must be factored into flap selection.
Reconstruction of complex abdominal wall defects that involve both musculofascial repair
and soft tissue replacement highlight the importance of coordinated collaboration between general surgeons and plastic and reconstructive surgeons.
The need for soft tissue coverage in abdominal wall reconstruction suggests a loss of
tissue beyond the availability of local tissue to be recruited to resurface the defect.
Because most abdominal wall defects can be reconstructed with the redundant tissue
usually found in the truncal area of most patients, these defects represent a more
complex subset of abdominal wall reconstructions. Indications for flap coverage
vary by cause of defect, defect type, and timeline for closure. Multiple clinical scenarios can lead to a loss of abdominal wall soft tissue requiring replacement including
oncologic resection, traumatic injury, radiation-associated wounds, skin necrosis, superficial soft tissue infection, and septic evisceration. The amount of soft tissue loss
and amount of coverage able to be performed with local skin advancement must be
factored into the reconstructive plan. Abdominal wall defects requiring soft tissue
coverage can be classified as partial-thickness defects, involving the skin and
Funding Sources: None.
Conflict of Interest: None.
Department of Plastic Surgery, Unit 1488, The University of Texas MD Anderson Cancer Center,
1400 Pressler, Houston, TX 77030, USA
* Corresponding author. Department of Plastic Surgery, Unit 1488, University of Texas
MD Anderson Cancer Center, 1400 Pressler, FCT 19.500, Houston, TX 77030.
E-mail address: [email protected]
Surg Clin N Am 93 (2013) 1199–1209
http://dx.doi.org/10.1016/j.suc.2013.06.005
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Baumann & Butler
subcutaneous tissue only, or full-thickness composite defects, which involve loss of
the abdominal wall musculofascia in addition to the overlying skin and subcutaneous
tissue. The indications for soft tissue replacement in abdominal wall reconstruction
also depend on the chronicity of the wound defect, with some defects benefiting
from early soft tissue coverage and others being more appropriate for delayed flap
coverage, whereas some defects might be better served with chronic wound care
and healing by secondary intention.
In the past, abdominal wounds were treated with wound care and allowed to heal
over time by secondary intention, or were reconstructed with a skin graft after the local
wound environment was optimized. This approach resulted in a protracted course of
care and significant morbidity. In time, the concept of delayed primary closure gained
popularity, allowing certain patients with favorable wound characteristics to undergo
closure after a short period of a few days instead of being committed to weeks or
months of open wound care (Fig. 1).
Soft tissue flap reconstruction offers significant advantages compared with delayed
primary or secondary healing wound closure. Flap reconstruction is performed in a
single-stage procedure obviating chronic wound management. Flap reconstruction
offers immediate and definitive wound closure mitigating the local milieu inflammatory
response and local tissue injury. In reconstructions involving bioprosthetic mesh these
two factors are critical in that, if the mesh is interposed between two well-vascularized
tissue planes (posterior abdominal wall/peritoneal cavity and a soft tissue flap superficially), then bilaminar vascular ingrowth can be achieved, accelerating the period of
bioprosthetic mesh revascularization and incorporation. In addition, a closed wound
environment diminishes the proinflammatory state of an open wound, which limits
the degree of enzymatic degradation of the bioprosthetic mesh during the incorporation phase.
Over the last 15 years, negative-pressure wound therapy (NPWT) has revolutionized
the approach to wound care, particularly in the abdominal wall. NPWT allows preservation of the wound environment by managing fluid losses, decreasing bacterial
contamination, and accelerating granulation tissue formation. In abdominal wall
reconstruction this preserves the option for delayed closure by flap reconstruction
or delayed primary closure.
Planning for flap reconstruction in the abdominal wall must factor defect type,
defect location, availability of surrounding soft tissue, and, in certain cases, planned
reoperation. Flap reconstructions can be classified by where the tissue is recruited
and their blood supplies: local flaps, random or axial; regional flaps, pedicled; and
free flaps, microanastomoses.
LOCAL FLAP OPTIONS
Local flaps involve recruiting tissue adjacent to the wound defect. Well-planned incisions are critical to preserve blood supply to the local flap and avoid wound healing
complications at the donor site used to resurface the wound defect. There are various
flap transposition designs available including advancement, rotation/advancement,
interpolation, V-Y advancement, and bipedicled flaps. These flaps can be oriented
in various dimensions, including vertical, oblique, and horizontal. These flaps are
perfused through random or axial blood supplies, so understanding of the vascular
anatomy in terms of abdominal wall angiosomes and perforator location is critical to
designing robust local flaps.
It is also important to consider the impact of preexisting incisions in the abdominal
wall when planning a flap design. A midline laparotomy may preclude harvesting a
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Fig. 1. Delayed primary fasciocutaneous flap closure. A 58-year-old man developed anastomotic leak after laparoscopic esophagectomy. The patient underwent multiple washouts
and was treated as an open abdomen for 2 weeks (A). Abdominal wall closure with inlay
bridging bioprosthetic mesh and bilateral component separation was performed and the
patient underwent negative-pressure wound therapy (NPWT) for 2 weeks (B). Next he
underwent skin debridement and advancement flap delayed primary closure (C, D). Twoyear postoperative computed tomography follow-up (E). (Courtesy of D.P. Baumann, MD,
Houston, TX. Copyright Ó 2009 Donald Baumann.)
local flap from the contralateral abdominal wall. However a midline defect bisected by
a laparotomy scar can be divided in half and reconstructed by 2 local flaps, one from
each hemiabdomen. Another key factor in performing a local flap reconstruction is
limiting tension across the wound closure at both the defect site and the donor site.
The flap perfusion, especially at the most distal part of the flap, can be compromised
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if the flap is placed on high tension either by pushing the limits of the flap design or by
creating excessive biaxial tension across the flap when the donor site is closed. One
strategy that can be used to mitigate excessive tension is to transpose the flap to
cover the defect site and then skin graft the donor site.
For midline defects, a bipedicled flap is generally used for midline defects either
unilaterally or bilaterally. The flap is oriented vertically with a minimum of a 3:1
length/width ratio and maintains a blood supply from both the superior and inferior aspects of the flap.1 The flap is then directly transposed to resurface the defect and, by
design, the donor site cannot be closed without an undue degree of tension. To offload
the tension a skin graft is placed on the donor site, preserving blood supply to the
distal flap to maximize wound healing. The keystone flap is one strategy to reconstruct
large trunk defects (Fig. 2). The keystone flap enables 1-stage resurfacing of the both
the defect and donor site. The flap is designed as a large 3:1 ellipse parallel to the long
axis of the defect.2 The blood supply to the flap is based on cutaneous perforators that
shift toward the defect when the flap is advanced. Once the leading edge of the
Fig. 2. Keystone flap. A 24-year-old woman with sarcoma of the upper lateral thigh. (A) The
sarcoma has been removed and the resultant defect is marked for keystone island flap
repair; note the large defect size. (B–D) The flap is freed and ready for inset without the
need for undermining. (E) The redundant inner corners of the flap are marked and trimmed
to prevent standing cutaneous deformity. (F) Final opposing V-Y primary closure.
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keystone flap is inset the donor site is closed on itself from the poles of the long axis of
the flap to the side of the flap remote from the defect. This flap succeeds because of
the transposition tension from the advancement and closure being distributed over the
long circumference of the flap skin island.
REGIONAL FLAP OPTIONS
In cases in which the defect size exceeds the availability of local soft tissue for
coverage, the next option is to consider a regional flap. Regional flaps are pedicled
flaps based on a dominant axial blood supply that can be delivered into the abdominal
wall to support tissue perfusion in the flap’s new location. Regional pedicled flaps are
harvested from adjacent anatomic areas such as the chest, groin, thigh, or back. Pedicled flaps can be designed as either fasciocutaneous flaps, myocutaneous flaps, or
muscle flaps resurfaced with a skin graft. When selecting a pedicled regional flap it
is important to consider the donor morbidity incurred. In addition, not only must the
flap’s ability to reach the defect be considered but also how the transferred flap will
tolerate the rotational and flexion/extension forces placed on it in the trunk. As an
example, because the flap’s pedicle vessels remain in their position of origin, the
flap can traverse the groin or flank and have its blood flow compromised by compression or rotation in these areas (Fig. 3). Pedicled regional flap options for abdominal
wall reconstruction include latissimus and serratus flaps for upper lateral defects
and thigh-based flaps (anterolateral thigh [ALT], vastus lateralis/medialis, and tensor
fascia lata [TFL]) for lower abdominal wall defects.
FREE TISSUE TRANSFER
Microsurgical free tissue transfer increases the capacity of the reconstructive surgeon
to provide soft tissue coverage for abdominal wall defects that are not amenable to
either local or regional flap coverage. Flaps of most sizes, volumes, dimensions,
and compositions can be transferred from donor sites remote from the abdominal
wall. Although more technically demanding, the evolution of microsurgical techniques
enables successful free flap transfer in excess of 98% of cases.3
FLAP DONOR SITE OPTIONS
There are many free flap donor site options available for abdominal wall reconstruction
(Table 1). The torso and thigh are the main areas of flap harvest for defects in the upper abdominal wall and epigastrium to the suprapubic region. Flaps can be harvested
from these donor sites as either pedicled flaps or free flaps. The posterior chest wall
donor site yields the latissimus dorsi and serratus anterior muscle flaps. These two
flaps can be harvested as muscle flaps or myocutaneous flap designs. In addition,
they can be harvested together as a chimeric flap to increase the tissue volume for
flap transfer. These flaps can be transposed to the upper epigastrium or subcostal region as a pedicled flap. For defects beyond the reach of the thoracodorsal pedicle the
flap can be converted to a free flap and transposed anywhere in the abdominal wall
(Fig. 4).
In cases in which a large skin paddle is required for the abdominal wall defect, a free
scapular or parascapular flap can be designed on the circumflex scapular branch of
the subscapular arterial system. If a latissimus or serratus flap is harvested, the functional donor site impact must be considered as it relates to the weakened abdominal
wall. In addition, in terms of logistical planning, the patient must undergo a position
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Fig. 3. Pedicled anterolateral thigh flap reconstruction of abdominal wall. A 45-year-old
woman developed a pelvic abscess with fascial dehiscence after undergoing hysterectomy,
oophorectomy, and abdominoperineal resection. She underwent multiple washouts and
open-abdomen NPWT management (A). She then underwent exploration and reconstruction with inlay bridging bioprosthetic mesh (B, C). A left-sided anterolateral thigh flap
was harvested and pedicled on the descending branch of the lateral femoral circumflex
system up into the abdominal defect (D, E). The flap was then partially deepithelized and
inset (F). The patient at 4-week follow-up (G). (Courtesy of D.P. Baumann, MD, Houston,
TX. Copyright Ó 2011 Donald Baumann.)
change to facilitate flap dissection in the posterior chest wall, which adds complexity
and additional time to the procedure.
The thigh represents the mainstay for flap donor sites. Both pedicled flaps for
coverage of the infraumbilical abdominal wall and free flaps can be designed in several
configurations: fasciocutaneous, myocutaneous, muscle, and chimeric flaps. The
descending branch of the lateral circumflex femoral system provides blood supply
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Table 1
Abdominal wall flap reconstruction algorithm
Location
Regional/Pedicled Flap
Free Flap
Epigastric region
Latissimus dorsi
Transposition flap (intramuscular perforators)
Thigh-based flap
Latissimus dorsi
Periumbilical region
External oblique
Bipedicled fasciocutaneous
Thigh-based flap
Latissimus dorsi
Hypogastric region
External oblique
Bipedicled fasciocutaneous
Thigh-based flap
TFL
Thigh-based flap
Latissimus dorsi
to the vastus lateralis and rectus femoris muscles. The transverse branch of the lateral
circumflex femoral system provides blood supply to the TFL muscle. These flaps can
be harvested as muscle-only flaps or with overlying skin paddles. The anterolateral
thigh flap is designed by including a skin paddle overlying the vastus lateralis muscle
and can be designed as a myocutaneous or fasciocutaneous flap. The TFL flap can be
designed to include the distal fascia of the iliotibial tract and a smaller proximal skin
paddle if needed.4 The anteromedial thigh flap can be designed on medial perforators
from the descending branch of the lateral circumflex femoral system. The rectus femoris muscle is most commonly designed as a muscle flap; however, a skin island can
be included over the central muscle when appropriately sized cutaneous perforators
are present.
These thigh-based flaps can be designed in any combination as chimeric flaps (ie,
ALT with anteromedial thigh (AMT) flaps, ALT with TFL, vastus lateralis with TFL).
Taken to the extreme, the vastus lateralis, TFL, and the rectus femoris can be harvested with all overlying skin territory as a subtotal thigh flap for increased volume
and skin coverage for massive abdominal wall defects (Fig. 5).5
RECIPIENT VESSELS
The success of any free tissue transfer relies on the availability of suitable recipient
vessels providing arterial inflow and venous outflow to the free flap. There are several
recipient vessels available for abdominal wall reconstruction with free flaps. The main
vascular axis in the central abdominal wall is the internal mammary/superior epigastric/inferior epigastric system. The internal mammary and deep inferior epigastric
vessels provide large-caliber recipient vessels of 2-mm to 3-mm diameter for microanastomosis. However, the vessels are present at the most cephalad and caudal limits
of the abdominal wall. The main challenge for identifying recipient vessels is in the central aspect of the abdominal wall. In situ options include intramuscular components of
the distal superior and inferior epigastric systems or the terminal intercostal branches.
However, these vessels are smaller in caliber (1–2 mm) and present more technically
challenging microanastomoses. In cases in which the internal mammary-epigastric
axis is unavailable the thoracodorsal pedicle reach can be extended into the central
abdomen by way of vein grafts.
Recipient vessel options exist beyond the abdominal wall itself. There are several
options in the groin based on the superficial femoral system. The superficial inferior
epigastric artery, the superficial circumflex iliac artery, and the deep circumflex iliac
artery provide vessels of reasonable caliber for free flap transfer to the lower central
and lateral abdominal wall. If primary anastomosis is not feasible then vein grafts or
vein loops are required. Vein grafts are often harvested from the leg (greater or less
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Fig. 4. Free latissimus myocutaneous flap reconstruction of epigastric defect. A 63-year-old
patient with metastatic squamous cell carcinoma to abdomen and chest wall. Preoperative
view of ulcerated erosive lesion into abdominal cavity. (A) Composite full-thickness resection
of the abdominal wall including anterior reflection of diaphragm. Resultant thoracoabdominal composite defect. (B) Bioprosthetic mesh inlay bridging repair of the thoracoabdominal defect. (C) Free latissimus myocutaneous flap reconstruction of the epigastrium. Right
internal mammary vessels used as recipient vessels. Pedicle tunneled under the lower chest
wall skin flap (D, E, F). The patient at 3-week follow-up (G, H). (Courtesy of C.E. Butler, MD,
Houston, TX. Copyright Ó 2011 Charles Butler.)
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Fig. 5. Bilateral subtotal thigh flap reconstruction of a massive abdominal wall defect (A).
Abdominal wall defect musculofascial reconstruction with bioprosthetic mesh (B). Flap harvest. Pedicled right subtotal thigh flap included the rectus femoris muscle and a skin paddle
of 37 16 cm. Left subtotal thigh flap included the rectus femoris and tensor fasciae latae
muscles and a skin paddle of 40 18 cm (C). Flap inset with donor site skin grafts (D). Postoperative view at 10 weeks (E). (Courtesy of C.E. Butler, MD, Houston, TX. Copyright Ó 2009
Charles Butler.)
saphenous vein) or arm (cephalic vein). In addition, in abdominal wall reconstructions
with concurrent laparotomy intra-abdominal vessels can be used as recipients if there
are no local options in the abdominal wall. The omental and gastroepiploic vessels can
be easily mobilized to reach the undersurface of the abdominal wall. Care must be
taken in insetting and supporting the flap pedicle so that there is no tension on the
anastomoses when the visceral contents shift when the patient transitions from supine
to sitting/standing. In addition, the morbidity of reentering the abdominal cavity must
be considered if there is a vascular thrombosis. In addition, when bioprosthetic mesh
is used for the musculofascial reconstruction as an adjunct to the fascia of the flap the
pedicle traverses an aperture in the mesh, compromising the abdominal wall integrity
and potentially leading to a hernia defect. For these reasons local recipient options
should be explored before intra-abdominal vessels are selected.
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Vein grafts and arterialized vein loops provide recipient vessels in the central abdominal wall. Vein grafts can be harvested from either the upper or lower extremity as a cephalic vein graft or saphenous vein graft. For central and lower abdominal defects an
arterialized saphenous vein loop can be designed. The saphenous vein is dissected
and transected distally and then anastomosed to the superficial femoral artery or a
side branch. This technique allows delivery of the loop to the flap’s recipient site where
the loop is divided providing an arterialized afferent limb and a venous drainage efferent
limb. This technique only requires 3 anastomoses instead of 4, as is the case with direct
arterial and venous vein grafts. The main recipient vessel sites for vein grafts or arterialized vein loops are the thoracodorsal vessels; internal mammary vessels; branches of
the superficial femoral system and the deep inferior epigastric vessels can be used to
extend the reach of vein grafts to the central abdominal wall.
ABDOMINAL WALL TRANSPLANTATION
Abdominal wall transplantation represents the zenith of abdominal wall flap reconstruction. It is generally reserved for patients undergoing single-organ or multiorgan
visceral transplants in which abdominal wall closure by autologous flaps is not technically feasible or presents significant donor morbidity. Abdominal wall closure after
visceral organ transplantation is challenging in the setting of donor/recipient organ
size mismatch and/or prior recipient abdominal surgery. Transplant patients can
benefit from vascularized composite allotransplants as an additional strategy to
expand the domain of the abdominal cavity to allow for either a graft/recipient size
mismatch or inability for closure in the event of extreme intestinal edema. Although
the risks of lifelong immunosuppression potentially outweigh the benefits of abdominal
wall transplantation in healthy nontransplant patients, transplant patients are already
bound to an immunosuppressive regimen and can benefit from the addition of allograft
abdominal wall musculofascial tissue to reduce abdominal wall wound complication at
the time of transplantation.
In the setting of transplant immunosuppression, the risk of an open abdominal
wound, fascial dehiscence, septic evisceration, or fistula carries significant morbidity
and potential mortality. When conventional abdominal wall closure techniques are
insufficient, allotransplantation is performed. Extensive study of the vascular supply
of the abdominal wall has allowed design of musculofasciocutaneous flaps based
on the deep inferior epigastric (DIEP) system. These flaps can be transferred based
on either the DIEP vessels through microsurgical techniques or the external iliac for
a macrovascular anastomosis. Selvaggi and colleagues6 describe a series of 15
abdominal wall transplants with 3 episodes of rejection salvage with modulating
immunosuppression and 2 flap losses caused by vascular thrombosis.
Pediatric transplant patients present challenges in managing graft/recipient size
mismatches and have the potential for needing advanced reconstructive options for
abdominal wall closure. Given the microsurgical challenges associated with pediatric
vessel caliber, alternative strategies for abdominal wall transplantation have been
developed. Agarwal and colleagues7 described a novel flap design for pediatric liver
transplant patients.8,9 They design a posterior rectus sheath fascioperitoneal flap
based on the terminal branches of the hepatic artery via the falciform ligament, which
enables transfer of the vascularized posterior sheath in continuity with the liver by
means of the falciform ligament without the requirement for additional vascular
anastomoses.
Abdominal wall transplantation is in its earliest stages. It has virtually eliminated
the issue of donor site morbidity and future advances will likely focus on improved
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recipient site function. To this end, refining flap design even further to include dynamic
neurotized flap transfers that can provide stable abdominal wall contour and preserved truncal core muscular stability will represent a new era in abdominal wall
reconstruction.
REFERENCES
1. Smith PJ. The vascular basis of axial pattern flaps. Br J Plast Surg 1973;26(2):
150–7.
2. Khouri JS, Egeland BM, Daily SD, et al. The keystone island flap: use in large defects of the trunk and extremities in soft-tissue reconstruction. Plast Reconstr
Surg 2011;127(3):1212–21.
3. Bui DT, Cordeiro PG, Hu QY, et al. Free flap reexploration: indications, treatment,
and outcomes in 1193 free flaps. Plast Reconstr Surg 2007;119(7):2092–100.
4. Chalfoun CT, McConnell MP, Wirth GA, et al. Free tensor fasciae latae flap for
abdominal wall reconstruction: overview and new innovation. J Reconstr Microsurg 2012;28(3):211–9.
5. Lin SJ, Butler CE. Subtotal thigh flap and bioprosthetic mesh reconstruction for
large, composite abdominal wall defects. Plast Reconstr Surg 2010;125(4):
1146–56.
6. Selvaggi G, Levi DM, Cipriani R, et al. Abdominal wall transplantation: surgical
and immunologic aspects. Transplant Proc 2009;41(2):521–2.
7. Agarwal S, Dorafshar AH, Harland RC, et al. Liver and vascularized posterior
rectus sheath fascia composite tissue allotransplantation. Am J Transplant
2010;10(12):2712–6.
8. Lee JC, Olaitan OK, Lopez-Soler R, et al. Expanding the envelope: the posterior
rectus sheath-liver vascular composite allotransplant. Plast Reconstr Surg 2013;
131(2):209e–18e.
9. Ravindra KV, Martin AE, Vikraman DS, et al. Use of vascularized posterior rectus
sheath allograft in pediatric multivisceral transplantation–report of two cases. Am
J Transplant 2012;12(8):2242–6.
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