Wound Healing

Author Credentials 

Myriam Loyo, MD
Assistant Professor
Division of Facial Plastic & Reconstructive Surgery
Department of Otolaryngology–Head & Neck Surgery
Oregon Health & Science University
Portland, OR

Brian L. Scott, MD
Resident Physician
Division of Facial Plastic & Reconstructive Surgery
Department of Otolaryngology–Head & Neck Surgery
Oregon Health & Science University
Portland, OR

Module Summary

Wound healing proceeds through a stepwise fashion from hemostasis to inflammation to proliferation to remodeling. Surgeons can promote tissue healing by handling tissue carefully, preventing infection, and creating a tension-free and moist wound environment. Patients should be encouraged to refrain from smoking, moderate-heavy drinking, and controlling glycemic levels in the perioperative time period. Vitamin, mineral, and protein deficiencies are correlated with impaired wound healing and supplementation should be offered if malnutrition is suspected. 

Module Learning Objectives 

After completing this module, the physician will:

  1. Review basic skin anatomy as it relates to wound healing.
  2. Describe the types of wound closures and be able to classify wounds.
  3. Explain the phases of wound healing.
  4. Recognize how the tenets of halsted and skin tension contribute to optimal wound healing.
  5. Review factors which impair wound healing.
Anatomy
  • Layers of skin
    1. Epidermis – stratum corneum, lucidum, granulosum, spinosum, basale
    2. Basement membrane
    3. Dermis
    4. Subcutaneous tissue (hypodermis, subcutis)
  • Vascular Anatomy
    1. Angiosome – 40 skin regions and connecting choke vessels
    2. Perforating arteries – direct and indirect perforators
    3. Microvascular plexus – subdermal and subpapillary plexus
Wounds and Closures

Types of Closures

  1. Primary (first intention)
    1. Best cosmetic outcome
  2. Secondary (second Intention)
    1. Good for infected wounds
  3. Tertiary

Wound Classification

  • Class 1: Clean
  • Class 2: Clean Contaminated
  • Class 3: Contaminated
  • Class 4: Dirty

Bite Wounds
Dog/Cat/Human

  • Augmentin for 3-5 days
  • Generally okay to close bites to the head and neck 

Traumatic Wounds

  • Primary closure to improve cosmesis preferred
  • Systemic antibiotics if high-risk (immunocompromised, laceration > 5 cm, penetrating wound)
Phases of Wound Healing
  1. Phase 1: Hemostasis
    • Vasoconstriction  platelet plug  coagulation
  2. Phase 2: Inflammation 
    • Lasts 5-7 days. Phagocytosis by neutrophils and macrophages 
  3. Phase 3: Proliferation
    • Re-epithelization begins < 24 hours and complete by ~ 48 hours if incision approximated. Moist wound surface enhances epithelial migration
    • Granulation tissue begins to form days 3-4
    • Scar formation – type 3 collagen predominates in early scar, haphazard collagen leads to reduced tensile strength
  4. Phase 4: Remodeling
    • Lasts 1-2 years as disorganized type 3 collagen is replaced with organized type 1 collagen bundles increasing tensile strength 
Optimizing Wound Healing

Tenets of halsted - Gentle tissue handling, hemostasis, preservation of blood supply, aseptic technique, minimizing tissue tension, obliteration of dead space, close tissue apposition

Relaxed skin tension lines (RSTL) - Ideal placement for incisions to minimize scarring

Lines of maximal extensibility (LME) - Helps determine the donor site in flap reconstruction

Basic Wound Care
  1. Debridement – necrotic tissue is an inflammatory stimulus and harbinger of bacteria
  2. Moisture – enhances epithelization
  3. Infection control
  4. Negative pressure dressings – promotes angiogenesis
  5. Hyperbaric oxygen – often considered for radiation wounds

Factors Which Impair Wound Healing: 

  1. Hypoxia
  2. Infection
  3. Advanced age
  4. Emotional and physical stress
  5. Diabetes
  6. Obesity
  7. Alcohol
  8. Smoking
  9. Nutritional deficiencies 
    • Zinc, protein, vitamins A, C, E
Case Studies
  1. A 42 year old female presents for evaluation 2 weeks after thyroidectomy with a hypertrophic neck scar
    • Silicone gel can be used to decrease scar hypertrophy
    • Injection of steroid and/or 5-fluoracil and decrease scar hypertrophy
    • Scar revision can be offered if the prior measure fail to improve the scar 
  2. A 39 year old female is referred to you for excision of a newly diagnosed superficial spreading melanoma of the left cheek measuring 1.3 x 0.5 cm with a depth of 1 mm.
    • The patient will require excision of the melanoma of the cheek with margins
    • The incisions for the excision should align parallel to the RSTL of the cheek 
    • Reducing skin tension will improve the resultant scar
  3. A 74 year old male presents for follow up 10 days after undergoing a wide local excision and skin graft reconstruction of a cutaneous squamous cell carcinoma of the nasal tip. On exam, the graft is firm, black, and dissected. The surrounding skin is erythematous and purulent drainage is noted.
    • There is necrosis of the skin graft and a surgical site infection. To promote healing, necrotic tissue should be debrided and the wound should be irrigated and cleaned. Topical and oral antibiotics should be considered. 
    • Local wound care would be used to promote healing in the area and prevent further desiccation
Review Questions
  1. Which type of wound closure generally produces the best cosmetic outcome?
  2. What is the difference between a clean contaminated wound and a contaminated wound?
  3. What are the four stages of wound healing?
  4. Describe the wound and patient factors which impair wound healing.
References
  1. Frodel JL, Brenner, MJ. Wound Healing. In:  Papel ID, Frodel JL, Holt GR Larrabee WF, Nachlas NE, Park SS, Skyes JM, Toriumi DM, eds. Facial Plastic and Reconstructive Surgery. 4th ed. New York: Thieme; 2016.
  2. Bevans S. Basic Techniques, Surgical Anatomy, Histology. In: Wong BJ, Arnold MG, Boeckman JO, eds. Facial Plastic and Reconstructive Surgery: A Comprehensive Study Guide. Switzerland: Springer International Publishing; 2016: 23-38.
  3. Jefferson GD. Dynamic Wound Healing. In: Johnson, JT, Rosen CA, eds. Bailey’s Head and Neck Surgery – Otolaryngology. 5th ed. Philadelphia, PA: Wolters Kluwer Health/Lippincott Williams & Wilkins; 2014: 75-85.
     
Resources 

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