Wound Healing Dr Ahmad Alamadi FRCS Consultant Otolaryngologist Al Baraha Hospital

Objectives Definition Mechanism Stages Factors affecting wound healing Wound assessment

Definition Restoration of tissue continuity after injury Repair vs. Regeneration

Mechanisms Healing by first intention  Clean  Incised surgical  Minimum tissue loss  Wound edge closely opposing Result ……healing with minimal scar

Mechanisms Healing by Second intention  Dirty  Traumatic wounds  tissue loss  Wound edge not closely opposing Result ……healing with large scar

Stages Haemostasis Inflammation Granulation Remodeling

Haemostasis Blood vessel constrict Clot formation

Inflammatory phase Platelet PG Seratonin PDGF Mast Cells Neutrophils Macrophages

Proliferation (Granulation) Angiogenesis Fibroblast activity  Connective tissue matrix  Collagen  Hyaluronic acid Epidermal cell migration

Remodeling (Maturation) 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 Infection Foreign body Oxygen Smoking Wound tension Blood supply Temperature Nutritional status Ageing Underlying disease Drugs Wound dressing Electrotherapy Ultrasound therapy Laser therapy

Infection Bacteria uses oxygen and nutrients They produce lactic acid and endotoxins Release of protease enzymes from inflammatory cells

Oxygen Needed for phagocytosis For collagen synthesis for hydroxylation of proline and lysine Hypoxia may be due to  Atherosclerosis  Diabetes mellitus  Venous insufficiency  edema  smoking

Blood supply Provide;  Inflammatory cells  Oxygen  Nutrients Remove waste material Radiation damages microvascularture

Nutritional status Poor intake Abnormal absorption Increased demand Carbohydrates source of energy Proteins for collagen synthesis Vitamins 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 Zinc, copper & Iron

Ageing Delayed inflammation Decreased wound contraction Decreased proliferation Angiogenesis reduced Reduced fibroblast activity Epithelialization is slowed

Drugs Anti-inflammatory drugs  Steroids reduce neutrophil and monocyte recruitment  Steroids inhibit fibroblast activity Cytotoxic Anticoagulants

Wound dressing Protect from physical trauma Keep wound moist

Ultrasound therapy 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 Improves wound healing Improves wound contraction at 700hz Improves fibroblast migration Stimulates mast cells Stimulates production of wound mediators

Wound assessment Invasive  Biopsy  Angiography Non Invasive  Transparency tracing  Photographic tracing  Depth gauges  Volume  Thermal imaging  Ultrasound

Questions?? Reference Scott- Brown’s Otolaryngology sixth edition volume 1 basic sciences Cummings Otolaryngology: Head and Neck Surgery 4 edition