1. NORMAL WOUND HEALING CLINICAL IMPLICATIONS
1. Meticulous hemostasis reduces inflammation & phagocytosis necessary to clear wound of blood
2. Atraumatic handling of tissues decreases load of necrotic or non-viable cells at the wound margin
- use fine forceps or skin hooks to retract & assist

2. NORMAL WOUND HEALING CLINICAL IMPLICATIONS
3. Deep sutures are best placed in collagen laden structures that can hold tension (fascia & dermis)
4. Fat does not contain collagen and does not hold sutures
5. Epithelialization more rapid under moist conditions than dry (Winter & Scales, 1963)

3. NORMAL WOUND HEALING CLINICAL IMPLICATIONS
6. Traditional wet-to-dry dressing, if truly left to dry, simply produces desiccation & necrosis of surface layer of wound during epithelialization
7. Without dressings, superficial wound forms scab or crust = protective moisture barrier

4. NORMAL WOUND HEALING CLASSIFICATION OF WOUNDS
Clean
Clean-Contaminated
Contaminated
Dirty

5. NORMAL WOUND HEALING CLASSIFICATION OF WOUNDS
CLEAN:
Non-traumatic, uninfected operative wound
Does not enter resp., GI, GU, or oral cavities
No inflammation is encountered
Closed primarily
Not usually drained
No break in aseptic technique occurs
75% of all surgical wounds fall into category

6. NORMAL WOUND HEALING CLASSIFICATION OF WOUNDS
CLEAN-CONTAMINATED:
Has usual normal flora
No gross contamination
Resp. and GI tract if no significant spillage
GU or biliary tracts if no infected urine or bile
Appendectomy
Clean wounds with a MINOR break in aseptic technique

7. NORMAL WOUND HEALING CLASSIFICATION OF WOUNDS
CONTAMINATED:
Soft tissue lacerations, open fractures, penetrating wounds and other trauma
Operations with gross spillage from GI tract
GU and biliary tracts with infected urine or bile
Operations with MAJOR break in aseptic technique. Eg emergency open cardiac massage

8. NORMAL WOUND HEALING CLASSIFICATION OF WOUNDS
DIRTY:
Wounds that are heavily contaminated
Wounds that are clinically infected pre-op
Abscess
Perforated viscera
Old traumatic wound with retained devitalized tissue or foreign body

9. NORMAL WOUND HEALING TYPES OF WOUND HEALING
1st Intention (Primary) Healing
2nd Intention (Secondary) Healing
3rd Intention (Tertiary) Healing
= Delayed Primary Closure
Partial Thickness Wounds

10. NORMAL WOUND HEALING TYPES OF WOUND HEALING
1st INTENTION (Primary) HEALING
Wound closed within 24 hours
Prior to formation of granulation tissue
Fastest healing
Generally best cosmetic result
Treatment of choice for non-infected wound
Time!! Infection Rate  Time since wounding
“Golden Period” vs. individual evaluation

11. NORMAL WOUND HEALING TYPES OF WOUND HEALING
2nd INTENTION (Secondary) HEALING
Open wound allowed to close by Contraction & Epithelialization
Contraction by myofibroblasts
Myofibroblasts disappear as contraction completed
Direct correlation between number of myofibroblasts and extent of wound contraction

12. NORMAL WOUND HEALING TYPES OF WOUND HEALING
3rd INTENTION (Tertiary) HEALING
= DELAYED PRIMARY CLOSURE
Contaminated, left open to prevent infection
Normal host defenses debride wound
After 3-4 days, local phagocytes and inflammatory cells recruited and angiogenesis
Wound edges approximated
Collagen metabolism undisturbed
Tensile strength develops as if primary closure

13. NORMAL WOUND HEALING TYPES OF WOUND HEALING
PARTIAL THICKNESS WOUNDS
Wounds involve epithelium and superficial dermis
Heal mainly by epithelialization to cover exposed dermis
Minimal collagen deposition
Absence of wound contraction
No or minimal scar formation

14. ABNORMAL WOUND HEALING

15. ABNORMAL WOUND HEALING ABNORMAL WOUND HEALING
Excessive Wound Healing:
Inadequate Wound Healing:

16. ABNORMAL WOUND HEALING ABNORMAL WOUND HEALING
Excessive Wound Healing:
Hypertrophic scar
Keloid scar
Inadequate Wound Healing:
Widespread scar
Chronic, unstable wound

17. ABNORMAL WOUND HEALING HYPERTROPHIC SCAR
Histologically similar to keloid scars
Overabundance of dermal collagen
Respect the boundaries of the original wound
Do not extend into unwounded skin
Less genetic predisposition
But do occur more frequently in Asian & Black populations

18. ABNORMAL WOUND HEALING HYPERTROPHIC SCAR
Often in upper torso & across flexor surfaces
Usually develop in first month after wound
Often subside gradually on own

19. ABNORMAL WOUND HEALING HYPERTROPHIC SCAR
TREATMENT OPTIONS:
Observation - may improve with time
Pressure garments
Topical silicone sheeting
Re-excision and closure (esp if wound was second intention or complicated by infection)

20. ABNORMAL WOUND HEALING KELOIDS
“Cheloide” - Alibert in 1816
True keloids uncommon
Etiology unknown
Histologically, overabundance of collagen: absolute number of fibroblasts not increased
Collagen production outpaces collagenase

23. Increased in Blacks: 6:1 to 19:1 Female > Male (min.)
KELOIDS Incidence
Increased in Blacks: 6:1 to 19:1
Female > Male (min.)
Mostly years old (but any age)
Commonest on ears, face, chest
Family history - autosomal dominant

24. IgG levels increased - ? Autoimmune
KELOIDS Etiology
IgG levels increased - ? Autoimmune
Aberration of melanocyte-stimulating hormone secretions
Sebum-antigen

25. Various abnormalities, significance unclear:
KELOIDS Biochemistry
Various abnormalities, significance unclear:
 TISSUE WATER
 CALCIUM
 ACID PHOSPHATASE
 G-6-P
 ALANINE TRANSAMINASE
 PROLINE HYDROXYLASE
 COLLAGENASE
 RATIO CLLAGEN TYPE III:TYPE I

26. Histologically identical Epithelium
KELOIDS Histology
Histologically identical
Epithelium
thin and flattened
rete pegs and dermal papillae absent
appendages decreased or absent
Dermis
elastic fibers absent
abnormally broad, swollen eosinophils
interlacing, glassy appearing collagen

27. Poorly circumscribed, dense connective tissue in dermis
KELOIDS Pathology
Poorly circumscribed, dense connective tissue in dermis
Skin of eyelids, areola, & penis - very thin, highly modified dermal layers: No Keloid
Only one authentic case of sarcomatous degeneration

28. Difficult because cause unknown
KELOIDS Treatment
Difficult because cause unknown
Some improvement with excision followed by intralesional steroid injection
Unresponsive cases, excision follwed by short course radiotherapy has been successful
Resulting scar unpredictable and potentially worse

32. ABNORMAL WOUND HEALING KELOIDS
PEARL:
Keloids exceed original boundaries of wound and continue producing collagen in pseudotumour fashion. (Distinguishes from hypertrophic scars)

33. NORMAL WOUND HEALING FACTORS AFFECTING WOUND HEALING
Anatomic Site: fastest in areas of greatest blood supply (face and neck)
Weight: fat most vulnerable tissue to trauma due to poor blood supply
Age: delayed healing, less wound strength
Oxygen: wound PO2, hyperbaric O2
Infection: local or systemic

34. NORMAL WOUND HEALING FACTORS AFFECTING WOUND HEALING
Medication: Chemotherapy, steroids
Local Factors: Wound tension, foreign body, dead or devitalized tissue
Nutritional Status: Protein, zinc, vitamins
Nature of Wound: Contusion, abrasion, laceration
Chronic Disease: Diabetes, cirrhosis

35. NORMAL WOUND HEALING FACTORS AFFECTING WOUND HEALING
Smoking: Nicotine induced vasoconstriction,
Toxins, Metalloproteinase stim’n
Radiation therapy: Stasis and vessel occlusion
Hydration: moist wound heals faster
Growth Factors : Endogenous or exogenous - stimulate wound healing - area of active research - no magic bullet to date

36. NORMAL WOUND HEALING
WOUND CLOSURE

37. NORMAL WOUND HEALING IDEAL SCAR
1. Accurate alignment of sharply incised tissue, parallel to natural line of resting skin tension.
2. Closure of wound without tension on epidermis & without underlying dead space
3. Primary healing without complications (eg. infection or dehiscence)
4. Patient’s genetic makeup - scar history
5. Wound location on body

44. WOUND HEALING SUTURE MATERIALS
Absorbable
Non-absorbable