Slide 1

Frederick N. Eko, MD Senior Fellow Division of Plastic Surgery Department of Surgery Tulane University School of Medicine

Slide 2

History of Wound Healing 1700 BC Papyrus: Lint/animal grease/honey 100 BC Egypt: Wound closure preserved soul 1000 AD Gun Powder 1500 AD Hot Oil 20 th Century Scientific Method

Slide 3

Wounds Customize Shotgun approach not acceptable No two patients OR wounds are identical 58y DM, Neuropathy: unaware of R foot gangrene

Slide 4

Slide 5

Wounds

Slide 6

Reconstructive Ladder Simple to Complex Formal Debridement, Elevation/ABIs Appropriate IV ABX, Wound Vac, Skin Graft

Slide 7

Review of Wound Healing Three basic types of healing Primary Delayed Primary Secondary

Slide 8

Primary Wound surfaces opposed Healing without complications Minimal new tissue Results optimal

Slide 9

Delayed Primary Left open initially Edges approximated 4-6 days later

Slide 10

Secondary Surfaces not approximated Defect filled by granulation Covered with epithelium Less functional More sensitive to thermal and mechanical injury

Slide 11

Secondary Wound Healing

Slide 12

Slide 13

Slide 14

Three Phases of Wound Healing Inflammatory Phase Proliferative Phase Remodeling Phase

Slide 15

Slide 16

Three Phases of Wound Healing Inflammatory Phase Proliferative Phase Begins when wound is covered by epithelium Production of collagen is hallmark 7 days to 6 weeks Remodeling Phase (Maturation Phase)

Slide 17

Inflammatory Phase Hemostasis and Inflammation Days 4 - 6 Exposed collagen activates clotting cascade and inflammatory phase Fibrin clot = scaffolding and concentrate cytokines and growth factors

Slide 18

Inflammatory: Granulocytes First 48 hours (Neutrophils) Attracted by inflammatory mediators Oxygen-derived free radicals Non-specific

Slide 19

Inflammatory: Macrophages Monocytes attracted to area by complement Activated by: fibrin foreign body material exposure to hypoxic and acidotic environment Reached maximum after 24 hours Remain for weeks

Slide 20

Inflammatory: Macrophages Activated Macrophage: Essential for progression onto Proliferative Phase Mediate: Angiogenesis: FGF, PDGF, TGF- & and TNF- Fibroplasia: ILs, EGF and TNF Synthesize NO Secrete collagenases

Slide 21

Slide 22

Slide 23

Inflammatory Phase

Slide 24

Slide 25

Slide 26

Three Phases of Wound Healing Inflammatory Phase Proliferative Phase Remodeling Phase

Slide 27

Proliferative Phase Epithelization, Angiogenesis and Provisional Matrix Formation Begins when wound is covered by epithelium Day 4 through 14 Production of collagen is hallmark 7 days to 6 weeks

Slide 28

Epithelialization Basal epithelial cells at the wound margin flatten (mobilize) and migrate into the open wound Basal cells at margin multiply (mitosis) in horizontal direction ) Basal cells behind margin undergo vertical growth (differentiation )

Slide 29

Slide 30

Proliferative: Fibroblast Work horse of wound repair Produce Granulation Tissue: Main signals are PDGF and EGF Collagen type III Glycosaminoglycans Fibronectin Elastin fibers Tissue fibroblasts become myofibroblasts induced by TGF-1

Slide 31

Wound Contraction Actual contraction with pulling of edges toward center making wounds smaller Myofibroblast: contractile properties Surrounding skin stretched, thinned Original dermal thickness maintained No hair follicles, sweat glands

Slide 32

Epithelialization/Contraction

Slide 33

Epithelialization

Slide 34

Slide 35

Collagen Homeostasis After Wounding (Optimal Healing) Days 3 - 7 Collagen production begins Days 7 42 Synthesis with a net GAIN of collagen Initial increase in tensile strength due to increased amount of collagen Days 42+ Remodeling with No net collagen gain

Slide 36

Collagen Normal Skin collagen ratio 4 : 1 Type I/III Hypertrophic Scar collagen ratio 2 : 1 Type I/III

Slide 37

Proliferative Phase

Slide 38

Three Phases of Wound Healing Inflammatory Phase Proliferative Phase Remodeling Phase

Slide 39

Maturation Phase Random to organized fibrils Day 8 through years Type III replaced by type I Wound may increase in strength for up to 2 years after injury Collagen organization Cross linking of collagen

Slide 40

Maturation Phase

Slide 41

Impaired Wound Healing

Slide 42

Wound Healing To treat the wound, you have to treat the patient Optimize the patient Circulatory Pulmonary Nutrition Associated diseases or conditions

Slide 43

Oxygen Fibroblasts are oxygen-sensitive PO2 < 40 mmHg collagen synthesis cannot take place Decreased PO2: most common cause of wound infection Healing is Energy Dependent Proliferative Phase has greatly increased metabolism and protein synthesis

Slide 44

Hypoxia: Endothelium responds with vasodilation Capillary leak Fibrin deposition TNF-a induction and apoptosis

Slide 45

Edema Increased tissue pressure Compromise perfusion Cell death and tissue ulceration

Slide 46

Infection Decreased tissue PO2 and prolongs the inflammatory phase Impaired angiogenesis and epithelialization Increased collagenase activity

Slide 47

Nutrition Low protein levels prolong inflammatory phase Impaired fibroplasia Of the essential amino Methionine is critical Hydration A well hydrated wound will epithelialize faster than a dry one Occlusive wound dressings hasten epithelial repair and control the proliferation of granulation tissue

Slide 48

Temperature Wound healing is accelerated at environmental temperatures of 30C Tensile strength decreases by 20% in a cold (12C) wound environment Denervation Denervation has no effect on either wound contraction or epithelialization

Slide 49

Diabetes Mellitus Larger arteries, rather than the arterioles, are typically affected Sorbitol accumulation Increased dermal vascular permeability and pericapillary albumin deposition Impaired oxygen and nutrient delivery Stiffened red blood cells and increased blood viscosity Affinity of glycosylated hemoglobin for oxygen contributing to low O2 delivery Impaired phagocytosis and bacterial killing Neuropathy

Slide 50

Radiation Therapy Acute radiation injury stasis and occlusion of small vessels fibrosis and necrosis of capillaries decrease in wound tensile strength direct, permanent, adverse effect on fibroblast may be progressive fibroblast defects are the central problem in the healing of chronic radiation injury

Slide 51

Medications Steroids Stabilize lysosomes and arrest of inflammation response Inhibit both macrophages and neutrophils Interferes with fibrogenesis, angiogenesis, and wound contraction Also direct effect on Fibroblasts Minimal endoplasmic reticulum Vitamin A oral ingestion of 25,000 IU per day pre op and 3d post op (not to pregnant women) Restores inflammatory response and promotes epithelializaton Does not reverse detrimental effects on contraction and infection

Slide 52

Nutritional Supplements Vitamin C ( Ascorbic Acid) Essential cofactor in synthesis of collagen Excessive concentrations of ascorbic acid do not promote supranormal healing Vitamin E Therapeutic efficacy and indications remain to be defined Large doses of vitamin E inhibit healing Increase the breaking strength of wounds exposed to preoperative irradiation

Slide 53

Nutritional Supplements Glutamine Enhance actions of lymphocytes, macrophages and neutrophils Glycine Inhibitory effect on leukocytes, might reduce inflammation related tissue injury Zinc common constituent of dozens of enzymes Influences B and T cell activity epithelial and fibroblastic proliferation is impaired in patients with low serum zinc levels

Slide 54

Factors in Wound Healing Smoking 1ppd = 3x freq of flap necrosis 2ppd = 6x freq of flap necrosis Nicotine acts via the sympathetic system Vasoconstriction and limit distal perfusion 1 cigarette = vasoconstriction > 90 min Decrease proliferation of erythrocytes, macrophages and fibroblasts Smoke contains high levels of carbon monoxide shifts the oxygen-hemoglobin curve to the left decreased tissue oxygen delivery

Slide 55

Syndromes Associated with Abnormal Wound Healing Cutis Laxa Think defective elastin fibers Congenital AD, recessive or X-linked recessive Acquired Drug, neoplasms or inflammatory skin conditions Ehlers-Danlos Syndrome Think defective collagen metabolism AD and recessive patters 10 phenotypes

Slide 56

Slide 57

Syndromes Associated with Abnormal Wound Healing Ehlers-Danlos Syndrome Connective tissue abnormalities due to defects: Inherent strength Elasticity Integrity Healing properties

Slide 58

Syndromes Associated with Abnormal Wound Healing Ehlers-Danlos Syndrome Four major clinical features Skin hyper-extensibility Joint hyper-mobility Tissue fragility Poor wound healing

Slide 59

Slide 60

Electrostimulation Electrical current applied to wounds Increases migration of cells 109% increase in collagen 40% increase in tensile strength 1 to 50 mA direct or pulsed based on wound

Slide 61

Hyperbaric Oxygen Developed 1662 by Henshaw: Domicillium Atmospheric pressure at sea level = 1 ATA = 1.5ml O2/dL Normal SubQ O2 tension is 30-50 mmHg. SubQ O2 tension < 30 mmHg = chronic wound

Slide 62

Excessive Healing Hypertrophic Scars Keloids

Slide 63

Hypertropic Scar

Slide 64

Keloids Extends beyond original bounds Raised and firm Rarely occur distal to wrist or knee Predilection for sternum, mandible and deltoid Rate of collagen synthesis increased Water content higher Increased glycosaminoglycans

Slide 65

Keloid Treatment Triamcinolone (steroid) injections 3-4 weeks Cross linking modulated Injections continued until no excess abnormal collagen Excise Prevention during healing pressure and injection

Slide 66

Keloid

Slide 67

Slide 68

Keloid Scar

Slide 69

Slide 70

Marjolins Ulcer Jean-Nicolas Marjolin (1828) Aggressive ulcerating SCC Occurs in setting of chronic inflammation Burn wounds Venous stasis ulcers Previous radiation therapy Characterized by Slow growth Painless Persistent granulation

Slide 71

Slide 72

Questions

Slide 73

The proliferative phase of wound healing occurs how long after the injury? A. 1 day B. 2 days C. 7 days D. 14 days

Slide 74

The proliferative phase of wound healing occurs how long after the injury? A. 1 day B. 2 days C. 7 days D. 14 days

Slide 75

Which type of collagen is most important in wound healing? A. Type III B. Type V C. Type VII D. Type XI

Slide 76

Which type of collagen is most important in wound healing? A. Type III B. Type V C. Type VII D. Type XI

Slide 77

The tensile strength of a wound reaches normal (pre-injury) levels: A. 10 days after injury B. 3 months after injury C. 1 year after injury D. never

Slide 78

The tensile strength of a wound reaches normal (pre-injury) levels: A. 10 days after injury B. 3 months after injury C. 1 year after injury D. never

Slide 79

Which of the following is commonly seen in Ehlers- Danlos syndrome? A. Small bowel obstructions B. Spontaneous thrombosis C. Direct hernia in children D. Abnormal scarring of the hands with contractures.

Slide 80

Which of the following is commonly seen in Ehlers- Danlos syndrome? A. Small bowel obstructions B. Spontaneous thrombosis C. Direct hernia in children D. Abnormal scarring of the hands with contractures.

Slide 81

Steroids impair wound healing by: A. Decreasing angiogenesis and macrophage migration B. Decreasing platelet plug integrity C. Increasing release of lysosomal enzymes D. Increasing fibrinolysis

Slide 82

Steroids impair wound healing by: A. Decreasing angiogenesis and macrophage migration B. Decreasing platelet plug integrity C. Increasing release of lysosomal enzymes D. Increasing fibrinolysis

Slide 83

Supplementation of which of the following micronutrients improves wound healing in patients without micronutrient deficiency? A. Vitamin C B. Vitamin A C. Selenium D. Zinc

Slide 84

Supplementation of which of the following micronutrients improves wound healing in patients without micronutrient deficiency? A. Vitamin C B. Vitamin A C. Selenium D. Zinc

Slide 85

Signs of malignant transformation in a chronic wound include: A. Persistent granulation tissue with bleeding B. Overturned wound edges C. Non-healing after 2 weeks of therapy D. Distal edema

Slide 86

Signs of malignant transformation in a chronic wound include: A. Persistent granulation tissue with bleeding B. Overturned wound edges C. Non-healing after 2 weeks of therapy D. Distal edema

Slide 87

The treatment of choice for keloids is: A. Excision alone B. Excision with adjuvant therapy (e.g. radiation) C. Pressure treatment D. Intralesional injection of steroids

Slide 88

The treatment of choice for keloids is: A. Excision alone B. Excision with adjuvant therapy (e.g. radiation) C. Pressure treatment D. Intralesional injection of steroids

Slide 89

The major cause of impaired wound healing is: A. Anemia B. Diabetes mellitus C. Local tissue infection D. Malnutrition

Slide 90

The major cause of impaired wound healing is: A. Anemia B. Diabetes mellitus C. Local tissue infection D. Malnutrition

Slide 91

Bradykinin, serotonin, and histamine in wounds are released from: A. Lymphocytes B. Mast cells C. Polymorphonuclear leukocytes D. Platelets

Slide 92

Bradykinin, serotonin, and histamine in wounds are released from: A. Lymphocytes B. Mast cells C. Polymorphonuclear leukocytes D. Platelets

Slide 93

Platelets in the wound form a hemostatic clot and release clotting factors to produce: A. Fibrin B. Fibrinogen C. Thrombin D. Thromboplastin

Slide 94

Platelets in the wound form a hemostatic clot and release clotting factors to produce: A. Fibrin B. Fibrinogen C. Thrombin D. Thromboplastin

Slide 95

In a healing wound, metalloproteinases are responsible for: A. Establishing collagen cross-link B. Glycosylation of collagen molecules C. Incorporation of hydroxyproline into the collagen chain D. Initiating collagen degradation

Slide 96

In a healing wound, metalloproteinases are responsible for: A. Establishing collagen cross-link B. Glycosylation of collagen molecules C. Incorporation of hydroxyproline into the collagen chain D. Initiating collagen degradation

Slide 97

Severe cases of hidradenitis suppurativa in the groin area are best managed by excision of the involved area and? A. Closure by secondary intension B. Delayed primary closure C. Primary closure D. Split thickness skin grafting

Slide 98

Severe cases of hidradenitis suppurativa in the groin area are best managed by excision of the involved area and? A. Closure by secondary intension B. Delayed primary closure C. Primary closure D. Split thickness skin grafting

Slide 99

All of the following statements about keloids are true except? A. Keloids do not regress spontaneously B. Keloids extend beyond the boundaries of the original wound C. Keloids or hypertrophic scars are best managed by excision and careful reapproximation of the wound D. Keloid tissue contains an abnormally large amount of collagen.

Slide 100

All of the following statements about keloids are true except? A. Keloids do not regress spontaneously B. Keloids extend beyond the boundaries of the original wound C. Keloids or hypertrophic scars are best managed by excision and careful reapproximation of the wound D. Keloid tissue contains an abnormally large amount of collagen.

Slide 101

The following photograph most accurately demonstrates: A. Hypertropic Scar B. Auricular Lymphedema C. Keloid Scar D. Cauliflower ear

Slide 102

The following photograph most accurately demonstrates: A. Hypertropic Scar B. Auricular Lymphedema C. Keloid Scar D. Cauliflower ear

Slide 103

The Proliferative Phase of wound healing is classically described as beginning: A. Immediately after injury B. When the wound is covered with epithelium C. When the collagen content has reached equilibrium D. When the macrophage enters the wound

Slide 104

The Proliferate Phase of wound healing is classically described as beginning: A. Immediately after injury B. When the wound is covered with epithelium C. When the collagen content has reached equilibrium D. When the macrophage enters the wound

Slide 105

Under ideal circumstances the tensile strength of the wounded area reaches what % of strength compared to normal skin? A. 10-20% B. 20-40% C. 60-70% D. 70-90%

Slide 106

Under ideal circumstances the tensile strength of the wounded area reaches what % of strength compared to normal skin? A. 10-20% B. 20-40% C. 60-70% D. 70-90%

Slide 107

Which of the following does NOT affect wound healing A. Infection B. Hydration C. Nutrition D. Denervation

Slide 108

Which of the following does NOT affect wound healing A. Infection B. Hydration C. Nutrition D. Denervation

Slide 109

Acknowledgements Edward R. Newsome, MD

Slide 110

Thank You