Wound healing is a complex, dynamic process involving several phases: inflammatory, proliferative, and remodeling. The inflammatory phase involves hemostasis and inflammation to limit blood loss and seal the wound. The proliferative phase fills the wound gap with granulation tissue through fibroplasia, angiogenesis, and re-epithelialization. The remodeling phase involves regression of vessels and granulation tissue, wound contraction, and collagen remodeling to strengthen the scar. Successful wound healing depends on factors like adequate blood supply, infection control, and avoiding risks such as smoking, which can impair healing.

1. WOUND HEALING MBBS, Resident Plastic surgery, HMC, Peshawar ansoor Khan M

2. Complex & dynamic process of restoring cellular structures & tissue layers

3. SCARING Full thickness wounds EPITHELIZATION Partial thickness wounds HEALING w o u n d h e a l i n g

4. Phases of wound healing

5. Inflammatory phase (day1-4)

6. Limit blood loss Debridement Sealing the wound

7. Inflammatory phase Haemostasis Inflammation

8. Vessel damage ---- bleeding---- platelet plug ---- thromboxane A2 --- Vascular contraction and coagulation pathway activation --- fibrin frame work deposition Haemostasis (Activated by intrinsic & extrinsic pathways)

9. Inflammation Serotonin/Histamine --- increased vascular permeability TGF– neutrophil chemotaxis, starts 6-8 hrs, max in 24 hrs Monocyte/ Macrophage– max 3-4 days Phagocytosis, cytokines (IL-1, TNF), mediators (TGF, PDGF, FGF) Activated by platelet secretary products (PDGF, TGF, FGF, Serotonin, Histamine)

10. Proliferative Phase (day 4-21)

11. Filling wound gap with granulation tissue

12. EVENTS Fibroplasia, angiogenesis, contraction, re-epithelization

13. FIBROPLASIA Chemotactic TGF, PDGF, EGF, IL-1 Fibroblasts peaks at 7 th day Collagen & Matrix deposition, Wound contraction 10-21 days

14. ANGIOGENESIS Hypoxia, lactic acidosis, and FGF-1 (most potent), heparin, TGF, prostaglandin Endothelial cells proliferation

15. EPITHELIALIZATION Basal layers thickens, elongates and cells detaches and migrates

16. Tailoring the way reality lives Phase (day 21-2years)

17. S hrinkage L oss of oedema S trength S care contraction

18. EVENTS Regression of vessels & granulation tissue Wound contraction Collagen remodelling (replacing collagen III with I) Maximum strength at the 12 week

19. WOUND CONTRACTION Begin in the proliferative phase (4-5 th day) Continues throughout the healing process Maximum 10-21 day Brings edges close at a rate of 0.6-0.75mm/day Depends on the laxity of the skin

20. LOCAL FACTORS Venn diagram

21. RISK FACTORS RISK FACTORS SYSTEMIC RISK FACTORS RISK FACTORS RISK FACTORS

22. ISCHEMIA Wound healing is a highly energy dependant process

23. Sugar is the main fuel for wound healing ISCHEMIA

24. So it take a rich blood supply to heal a wound ISCHEMIA

25. Initial response neo-vascularization Persistent ischemia results in apoptosis “ ”

26. INFECTION Collagenase production and destruction of collagen

27. FOREIGN BODIES Acts a physical barrier Asylum for bacteria Inability to contract Prevent epithelization

28. HYPOTHERMIA Vasoconstriction and decreased blood supply

29. PAIN Adrenaline surge causing vasoconstriction

30. Keep the wounds wet , warm and comfortable “ ”

31. SMOKING Vasoconstriction Which is not transient— 1 cigarette for 90 min 1 pack for whole day

32. SMOKING Carboxihemoglobin--- O2 carrying capacity. Subcutaneous PO2

33. 1 pack/ day--- 3 times increased chances of flap or graft loss 2 packs/day--- 6 times increased chances of loss of flaps and grafts SMOKING

35. STEROIDS Lysosomal stabalization--- impaired phagocytosis Impairment of chemotaxis of microphages Fibroblast genome inhibition--- decreased collagen, decreased strength and increased dehiscence

36. HEALING SLOWS DOWN WITH AGING

37. CUTIS LAXA SYNDROME

38. EHLER-DANLOS SYNDROME

39. OSTEOGENESIS IMPERFECTA

40. FETAL WOUND HEALING (SCARLESS) ADULT: collagen production, remodelling, scar formation FETAL: Altered growth substances (Tenascin etc), absence of inflammation, deposition of hyaluronic acid rich matrix and deposition of organized collagen leading to regeneration