Wound Healing 林燦勳醫師

Tissue injury and response  Wound repair  Tissue to restore normal function and structure after injury  Regeneration  Perfect restoration of the preexisting tissue architecture in the absence of scar

Wound closure type  Primary ( first-intension)  Simple suturing, skin graft replacement, or flap closure  Secondary ( spontaneous-intension)  Reepithelization and contracture  Tertiary (delayed primary)

Wound healing phase  Inflammatory phase  limit damage, preventing further injury  Proliferative phase  reepithelization, matrix synthesis, neovasculation  Maturation phase  Scar contraction with collagen cross-linking, shrinking, and loss of edema

( 一 ) Inflammatory phase  Hemostasis  Vascular permeability  Cellular recruitment 3 days, except infection

( 二 ) Proliferative phase  Angiogenesis  Epithelization, first 24hrs, peak 48hrs  Fibroplasia, day5 ~ 6 weeks  Formation of granulation tissue

( 二 ) Maturation phase  collagen cross-linking  collagen remodeling  wound contraction

III

 Wound contraction,1wk  Fibroblast and ECM interaction  Centripetal movement of skin  Reducing the amount of scar  Wound contracture  Excess scar  Physical constriction & limit function

Type of cutaneous wound  Full-thickness wounds  deeper than the adnexa  heal by contraction, granulation tissue formation and reepithelialization.  Contraction, 40% decrease in the size  Partial-thickness wounds.

Factors that inhibit wound healing  Infection(>10 5, any B-hemolytic strptococcus) any B-hemolytic strptococcus)  Ischemia Circulation Circulation Respiration Respiration Local tension Local tension  Diabetes mellitus Ionizing radiation  Advanced age  Malnutrition (albumin<2) (albumin<2)  Vitamin deficiencies Vitamin C Vitamin C Vitamin A Vitamin A  Mineral deficiencies Zinc Zinc Iron Iron  Exogenous drugs Doxorubicin (Adriamycin) Doxorubicin (Adriamycin) Glucocorticosteroids Glucocorticosteroids

Wound dressing  Antimicrobial salves  Antimicrobial soaks  Synthetic coverings  Biological covering (within 72 hrs, before high bacteria colonization)

Wound dressing

Synthetic coverings  Withour painful dressing changes, barrier, decrease pain, not inhibit epithelization  OpSite  Biobrane  Transcyte  Integra

Biobrane  1979  collagen-coated silicon in a sheet  adherent in hours  a barrier of moisture loss  relative painless wound  not require change dressing  impermeable to bacteria  complicated by exudate accumulation  risking invasive wound infection

 Clinical Indications:  superficial to mid-partial thickness burns  excised burn wound with or without meshed autografts  donor sites  partial thickness skin slough disorders

Duoderm  Pectin, gelatin: absorption of exudate, activate PMN, macrophage  Polyurethane foam: negative pressure, angiogenesis  PH: 6.2

Occlussive dressing

 Reepithelization  Dry wound < moist wound  Open wound < occlusive wounds

 Faster healing  Neovasculation within granulation tissue is stimulated by hypoxia  Prevent crust formation and dry of wound bed  Wound fluid – fibroblast proliferation  Not applied to inflammed eczematous skin and border of stasis ulcer

VAC (Vacuum-Assisted Closure)

VAC 治療的優點  降低局部水腫  增加局部血流  降低細菌滋生  促進肉芽組織形成  提供溼潤的癒合環境  促進上皮轉移  應用負壓以吸引傷口癒合

Principal indications for the use of the mains powered VAC  Acute and traumatic wounds  Subacute wounds (i.e. dehisced incisions)  Pressure ulcers  Chronic open wounds (stasis ulcers and diabetic ulcers)  Meshed grafts  Flaps

Small ambulant unit is recommended  Venous stasis ulcers  Lower extremity diabetic ulcers  Pressure ulcers  Lower extremity flaps  Dehisced incisions  Grafts

Contraindications for VAC  Fistulas to organs or body cavities  Necrotic tissue in eschar  Osteomyelitis (untreated)  Malignancy in the wound