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