Wound Healing

1
Wound Healing

• Dr Ahmad Alamadi FRCS
• Consultant Otolaryngologist
• Al Baraha Hospital

2
Objectives

• Definition
• Mechanism
• Stages
• Factors affecting wound healing
• Wound assessment

3
Definition

• Restoration of tissue continuity after injury
• Repair vs. Regeneration

4
Mechanisms

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

5
Mechanisms

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

6
Stages

• Haemostasis
• Inflammation
• Granulation
• Remodeling

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Haemostasis

• Blood vessel constrict
• Clot formation

8
Inflammatory phase

• Platelet
• PG
• Seratonin
• PDGF
• Mast Cells
• Neutrophils
• Macrophages

9
Proliferation (Granulation)

• Angiogenesis
• Fibroblast activity
• Connective tissue matrix
• Collagen
• Hyaluronic acid
• Epidermal cell migration

10
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

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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

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Infection

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

13
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

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Blood supply

• Provide
• Inflammatory cells
• Oxygen
• Nutrients
• Remove waste material
• Radiation damages microvascularture

15
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

16
Ageing

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

17
Drugs

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

18
Wound dressing

• Protect from physical trauma
• Keep wound moist

19
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

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Laser therapy

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

21
Wound assessment

• Invasive
• Biopsy
• Angiography
• Non Invasive
• Transparency tracing
• Photographic tracing
• Depth gauges
• Volume
• Thermal imaging
• Ultrasound

22
Questions??

• Reference
• Scott- Browns Otolaryngology sixth edition
  volume 1 basic sciences
• Cummings Otolaryngology Head and Neck Surgery 4
  edition