Wound healing

Moneer Almadani

Objectives

• Introduction
• Phases
• Types
• Wound closure
• Factors influencing wound healing
• Complications

Introduction

• Wound is a break in the skin
• Wound healing is the effort of injured tissue to restore normal function and structural integrity after injury
• A complex series of events, begins at the moment of injury and could continue for months to years

Healing, & tissue repair are central in surgery - Understanding the physiologic mechanism involved in process of wound healing -Create an environment where healing can proceed in an optimal fashion

Phases of healing

• Overlap in both time and activity
• All wounds undergo the same basic steps of repair
• Acute wounds proceed in an orderly and timely reparative function

• Chronic wounds stalled in the inflammatory phase, and doesn’t proceed to closure

A) Lag phase:

• Characterized by an inflammatory response to injury, during which capillary permeability increases and a protein-rich exudate accumulates

• Inflammatory cells migrate into the area, dead tissue is removed by macrophages, and capillaries at the wound edges begin to proliferate

• Elapses before fibroblasts begin to manufacture collagen to support the wound

2D before showering, to ensure good sealing - water proof wound after LAG stage epithelial prof

B) Incremental phase (Regenerative)

• Systemic stimulus for fibroblast activity.
• Progressive collagen synthesis by fibroblasts
• Increased in collagen turnover
• Old collagen undergoes lysis and new collagen is laid down
• Increased in tensile strength

C) Plateau phase: (Maturation) - 6 months final revision surgery

• After 3 weeks, the gain in tensile strength levels off
• Excess collagen is removed during this final clearing-up process
• Fibroblasts and inflammatory cells declined
• Skin and fascia recover only 80% of their original tensile strength

Types of surgical wounds

A) Primary (First intention)

• Wounds are sealed immediately
• Clean type
• Simple suturing, & Skin graft /flap

B) Secondary (Second intention) - leave it open, granulation healing, irrigation, daily dressing - 10D - 1M

• No closure
• Highly contaminated wounds
• Re-epithelialization > Wound contracture

C- Tertiary (Third intention)

• Delayed primary closure
• Contaminated wounds treated first, once the wound is clean then closed

Factors affect wound healing

Complications of wound healing

• Wound infection
• Evisceration - __
• Bleeding
• Adhesions - __
• Herniation - (incisional hernia)
• Sinus/Fistulation (communication between two epithelial surfaces)
• Suture complications
• Malignant changes
• Excessive healing (Hypertrophic scar- Keloid)

Excessive wound healing

Hypertrophic scar Vs. Keloid scar

References

• Principles and Practice of Surgery Pg 281-286