Wound Healing| | | | | | Wounds may contract as fast as 0.75 mm/day | | | | | |
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- Primary versus secondary intention healing
- Primary intention: direct closure of wound by approximating wound edges together (side-to-side closure, flaps, grafts)
- Secondary intention: wound left open and allowed to heal from inner to outer surface
- Wound contraction (maximal at 2 months after reepithelialization)
- Concave skin wounds (i.e., inner ear, nasal alar crease, temple) heal with best with secondary intention (vs. primary)
- Convex surfaces (i.e., malar cheek, vermilion border of lip, tip of nose) not optimal for healing by secondary intention and may cause ectropion or eclabion in areas with free margin of skin (nose, eyelids)
- Wound healing: four sequential overlapping stages
- Vascular phase: thrombin/exposed collagen results in stimulation of platelets, which release PDGF and other factors important for angiogenesis and fibroplasia → platelets aggregate forming hemostatic plug and damaged vessels are pressed together causing adherence to one another → overall result is hemostasis
- Inflammatory phase: neutrophils (first cell to arrive, often within first hour after injury) and macrophages (most important cell in healing process) recruited to wound site, phagocytosis of debris/bacteria
- Proliferative phase: reepithelialization within first 24 h of injury, production of collagen (type III); macrophages release fibronectin (which attracts fibroblasts) and other factors which induce angiogenesis and granulation tissue formation
- Wound contraction and remodeling: contraction via myofibroblasts, maximum strength of scar reached is 70–80% of original strength prior to injury
| | | | | | | | | Scar strength: 5 % at 2 weeks 15% at 3 woe ek s 40% at 6 weeks 80% at 1 year | | | | | | | | |
| | | | | | | Table 6-6 Types of Superficial Repair | | | Repair | | Pros | | Cons | | Use for: | | | Simple interrupted | | + provides wound eversion
+ allows high-low correction
+ individual sutures may be removed without disturbing remaining sutures | | − ↑ overall closure time
− ↑ net suture bulk with more prominent suture marks, skin irritation | | | | | Running | | + ↓ closure time
+ suture bulk spread over entire wound | | − integrity depends solely on knots on either end | | Use with minimal tension wounds | | | Vertical mattress | | + relieves tension
+ wound eversion | | − tendency to leave permanent suture marks | | High tension areas | | | Horizontal mattress | | + ↑ holding tension
+ wound eversion
+ hemostasis | | − ↑ tissue ischemia
− railroad track marks | | Tight situation where vertical mattress not possible | | | Running subcuticular | | + avoids any suture marks along skin surface | | − ↑ reactivity
− ↑ overall closure time | | Minimal tension and mobility
{Best with polypropylene glycol due to ↓ tissue reactivity} | | | | | | | | | |
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