Wound Healing Basics

Wound Healing

• Wound healing is the mechanism by which the body attempts to restore the integrity of an injured part.

Components of Wound Healing

• Wound contraction by myofibroblasts
• Granulation tissue formation
• Epithelialization

Stages of Wound Healing

• Clotting/Hemostasis
• Inflammatory Phase
• Proliferation Phase
• Maturation/Remodeling Phase

Types of Wound Healing

• Healing by Primary Intention: results in a nice, neat scar; occurs in clean cut wounds and incisional wounds (surgical); minimal new tissue (minimal fibrosis)
• Healing by Secondary Intention: gaping of the wound; occurs in contaminated wounds
• Delayed Primary Closure (Tertiary): wounds that are contaminated, left open for 4-5 days, then surgically closed by sutures

Factors Affecting Wound Healing

• General Factors:
  • Age
  • Nutritional Status: proteins, Vit.C, Vit.A., Zinc, Copper
  • Chronic Diseases: DM, Renal, Hepatic, Malignant Diseases
  • Drugs: Steroids, Chemotherapy
• Local Factors:
  • Vascularity (irradiation)
  • Impaired venous drainage (postphlebitic limb)
  • Tension (prevents contraction)
  • Immobilization (shearing forces)
  • Adhesion to bone
  • Foreign bodies and necrotic tissues
  • Infection

Wound Complications

• Early Complications:
  • Wound Infection
  • Wound Hematoma
  • Wound Seroma
  • Wound Failure (dehiscence): wound gaps after wound closure
• Late Complications:
  • Ugly scar
  • Hypertrophic scar
  • Keloid
  • Wound contractures
  • Malignant transformation (Marjolin ulcer)

Wound Failure

• Definition: wound gaps after closure
• Causes:
  • General factors
  • Local and technical factors
  • Postoperative course

Wound Seroma

• Definition: collection of serous fluid in the wound
• Causes wound swelling
• Needs observation or treatment
• Large or recollecting seroma is an indication of surgical evacuation

Wound Hematoma and Bleeding

• Stop the bleeding and replace if needed
• Bleeding may be minimal (Compression)
• If a bleeder is identified, suture it
• If bleeding affects the general condition, systemic and local management are needed

Scars

• Definition: the inevitable consequence of wound healing
• Final stage of wound healing is the stage of remodeling and scar formation
• Superficial wounds heal with epithelialization without scarring

Adverse Scars

• Wound contractures: decrease scar size with loss of tissue mobility due to skin adherence to the underlying tissue
• Hypertrophic Scar:
  • Overabundance of fibroplasia in the dermal healing process
  • Occur after trauma
  • Presented by tender- itching –burning sensation
  • Predisposed by hematoma and infection
  • Treatment: Excision and repair
• Keloid Scar:
  • Overabundance of fibroplasia in the dermal healing process
  • Occur after trauma
  • Presented by tender- itching –burning sensation
  • Genetically autosomal dominant disease and more common in negros
  • Rise above the skin level and extend beyond the border of the original wound
  • Treatment: Excision with intralesional cortisol injection or excision with topical application of silicon sheet