Download Wound Healing - Otology Textbook

Wound Healing
Dr Ahmad Alamadi FRCS
Consultant Otolaryngologist
Al Baraha Hospital
Objectives
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Definition
Mechanism
Stages
Factors affecting wound healing
Wound assessment
Definition
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Restoration of tissue continuity after injury
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Repair vs. Regeneration
Mechanisms
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Healing by first intention
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Clean
Incised surgical
Minimum tissue loss
Wound edge closely
opposing
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Result ……healing with minimal scar
Mechanisms
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Healing by Second intention
 Dirty
 Traumatic wounds
 tissue loss
 Wound edge not closely
opposing
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Result ……healing with large scar
Stages
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Haemostasis
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Inflammation
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Granulation
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Remodeling
Haemostasis
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Blood vessel constrict
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Clot formation
Inflammatory phase
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Platelet
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PG
Seratonin
PDGF
Mast Cells
Neutrophils
Macrophages
Proliferation (Granulation)
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Angiogenesis
Fibroblast activity
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Connective tissue matrix
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Collagen
Hyaluronic acid
Epidermal cell migration
Remodeling (Maturation)
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Replacement of granulation tissue by scar
Hyaluronic reduces and collagen type I
replaces type III and V
Increase tensile strength takes weeks
Collagen alignment and formation of bigger
bundles
Factors affecting wound healing
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Infection
Foreign body
Oxygen
Smoking
Wound tension
Blood supply
Temperature
Nutritional status
Ageing
Underlying disease
Drugs
Wound dressing
Electrotherapy
Ultrasound therapy
Laser therapy
Infection
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Bacteria uses oxygen and nutrients
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They produce lactic acid and endotoxins
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Release of protease enzymes from
inflammatory cells
Oxygen
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Needed for phagocytosis
For collagen synthesis for hydroxylation of
proline and lysine
Hypoxia may be due to
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Atherosclerosis
Diabetes mellitus
Venous insufficiency
edema
smoking
Blood supply
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Provide;
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Inflammatory cells
Oxygen
Nutrients
Remove waste material
Radiation damages microvascularture
Nutritional status
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Poor intake
Abnormal absorption
Increased demand
Carbohydrates source of energy
Proteins for collagen synthesis
Vitamins
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A Cross linking of collagen
C Hydroxylation of proline and lysine
K for clotting factors VII, IX &X
B for type III collagen secretion
E Antioxident
Minerals
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Zinc, copper & Iron
Ageing
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Delayed inflammation
Decreased wound contraction
Decreased proliferation
Angiogenesis reduced
Reduced fibroblast activity
Epithelialization is slowed
Drugs
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Anti-inflammatory drugs
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Steroids reduce neutrophil and monocyte
recruitment
Steroids inhibit fibroblast activity
Cytotoxic
Anticoagulants
Wound dressing
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Protect from physical trauma
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Keep wound moist
Ultrasound therapy
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Thermal effect improves wound healing
Non-thermal effect on membrane
permeability
Increase fibroblast motility
Improves angiogenesis
Accelerates wound contraction
Improves tensile strength and elasticity
Laser therapy
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Improves wound healing
Improves wound contraction at 700hz
Improves fibroblast migration
Stimulates mast cells
Stimulates production of wound mediators
Wound assessment
Invasive
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Biopsy
Angiography
Non Invasive
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Transparency tracing
Photographic tracing
Depth gauges
Volume
Thermal imaging
Ultrasound
Questions??
Reference
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Scott- Brown’s Otolaryngology sixth edition
volume 1 basic sciences
Cummings Otolaryngology: Head and Neck
Surgery 4 edition