Will it heal? How to assess the probability of wound healing Richard F. Neville, M.D. Professor of Surgery Chief, Division of Vascular Surgery George Washington University Limb center case 69 yr old male Non-healing amputation site DM, ESRD, CHF Active tobacco use Prior angioplasty at outside hospital Posterior tibial Doppler signal with ABI > 1.0 1
Revascularization for healing Principles of revascularization Establish pulsatile perfusion Surgical bypass Endovascular therapy Angiosome concept Wound care As important as the revascularization Fillet of toe 1 m 2 m 2
Lower-extremity wound healing Wound etiology Arterial ulcer Venous ulcer Need intervention to heal? What type of intervention? Wound care Arterial Ulcers Arterial occlusion PMH Coronary artery disease Diabetes mellitus Hypertension Tobacco use Symptoms Rest pain Tissue loss Exam Skin shiny, hairless, cool Dependent rubor No pulses Treatment Revascularization 3
Venous Ulcers Venous hypertension PMH DVT Calf muscle pump dysfunction Symptoms Dull ache/heavy legs/itching Exam Skin hyperpigmented, eczema Edema Palpable pulses Treatment Compression therapy Venous intervention Arterial vs Venous Ulcers Type Venous Arterial Site Size Gaiter region Medial malleolus Variable Toes/feet/heel Start small Look Diffuse Shallow depth Granulation tissue Punched out Deep (tendon/bone) Necrotic base 4
Clinical disease Arterial vs Venous: Ulcer Location Arterial wounds Diabetes mellitus Neuropathy Sensory Motor Autonomic Decubitus Vascular Insufficiency Tibial disease Medial calcinosis Minor Trauma Infection Increased risk Defective host defense 5
Diabetic foot Arterial Insufficiency Ischemia involved in 50% diabetic tissue loss Tibial artery occlusive disease Non-invasive Vascular Lab Segmental waveforms Segmental pressures PVRs Digital pressures / PVRs Duplex imaging Tissue perfusion TcO2 Skin perfusion pressure 6
Ankle-Brachial Index Vascular EKG Brachial BP DP / PT BP Calculate ABI Falsely elevated in diabetics Normal >0.9 Claudication 0.5 0.8 Rest pain <0.5 Critical ischemia < 0.3 ABI Compared to Other Common Screening Tests Diagnostic Test Sensitivity, % Specificity, % Pap smear 30-87 86-100 Fecal occult blood test 37-78 87-98 Mammography 75-90 90-95 ABI 95 98 AMA Archives of Internal Medicine Vol. 163. Apr 28, 2003 7
Segmental pressures/waveforms Arm Pressures For ABI Ankle Pressures for ABI PVR Measureme nts Pulse Volume Recordings Measure change in volume Amplitude < 15mm Ischemia Amplitude < 5mm Non-healing (A) normal characteristics (B) mild obstruction (C) moderate obstruction (D) severe obstruction or occlusion 8
Digital photoplethysmography Reflection of light in microcirculation Toe pressures Toe Brachial index Non-healing < 30-40 mmhg Toe Cuffs Arterial Study 9
Tests for tissue perfusion Tc02 Skin perfusion pressure Hyperspectral imaging SPY camera Questions Who needs revascularization? When is enough ---- enough? When should we work on the foot? Transcutaneous Oxygen Values measured at foot and chest wall Non-healing Value < 20-30 mmhg Chest foot index < 0.4 TcO2 post bypass peaks two to four weeks after revascularization Caselli A, et al Diabetic Med 2005;22(4):460-465. 10
Laser Doppler Technology Skin perfusion pressure Delivers a laser signal 1.5mm below skin Pressure cuff occludes capillary flow Controlled release of pressure Laser collects the Doppler shift effect of capillary flow return Calculates the Skin Perfusion Pressure - the pressure at which blood flow first returns to the capillaries Capillary ABI SPP Wound Healing Potential < 30 mmhg - wound healing failure > 30 mmhg predictor of wound healing SPP diagnoses PAD/CLI with > 80% accuracy Probability of Healing Probability 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0 5 1 0 1 5 2 0 2 5 3 0 3 5 4 0 4 5 5 0 SPP Castronuovo, et al. J. Vasc. Surg. 1997, 26, 629-637. 11
Who needs revascularization? Functional ischemia Disabling claudication Ischemic rest pain Tissue loss Non-healing ulcer Gangrene Severe ischemia on noninvasive testing Healing based on ulcer size 290 patients with ischemic wounds Grouped according to initial wound size Group A 0.1-5.0 mm Group B 5.1-20 mm Group C > 20 mm Neville, et al. SVS, 2010 12
Healing based on revascularization 100 90 80 70 60 50 40 30 20 10 0 Percent 81 76 54 Bypass Endo 42 27 Group A Group B Group C * 70 Neville, et al. Society for Vascular Surgery, 2010 * Log rank P value = 0.02 Healing based on angiosome concept Six distinct angiosomes: Posterior tibial artery (3) Calcaneal Medical plantar Lateral plantar Anterior tibial artery (1) Dorsalis pedis Peroneal artery (2) Lateral calcaneal Anterior perforator. Attinger C.E Plastic and Reconstr Surg 2006:117;261S-293S 13
Angiosomes Anterior Tibial Artery Dorsalis Pedis Anterior compartment Dorsum of foot Angiosomes Peroneal Artery Lateral Calcaneal branch Anterior Perforator branch Lateral ankle Lateral plantar heel Medial ankle 14
6/5/2014 Angiosome Posterior Tibial Artery Calcaneal Branch Medial Plantar Branch Lateral Plantar Branch Medial heel Medial plantar Lateral ankle/forefoot Lateral plantar Angiosomes of the Leg Indirect connections (Choke vessels) 15
Does it matter if the wound s angiosome is adequately perfused? Healing based on angiosome revascularization 100 80 60 40 20 0 91% Direct Fisher s exact P test = 0.03 P = 0.03 62% Indirect Complete healing Failed to heal 16
Principles of wound care Maximize functional length Biomechanically sound May need staged procedures Debridement Delayed wound closure VAC or other biologic adjuncts Wound care protocols 17
Debridement Principles Debride to viable tissue Culture exposed bone edges Reconstruct soft tissue When inflammation is gone Granulation tissue appears VAC as temporary dressing until closure Wet gangrene Debride ASAP Resect all necrotic tissue Explore tendon sheaths and fascial compartments VAC Mechanism Principle effects Decreases peri wound edema Increases granulation Decreases bacterial cell count MORYKWAS ET AL, APS 38:553, 1997 18
Bio debridement Maggot therapy 7 DAYS Primary amputation May be the right choice Lack of tissue Non-ambulatory Dementia 19
Amputation principles Think biomechanics and anatomy Maximize viable tissue Especially plantar surface Skeletal stability No pressure points Rebalance tendons No pressure points Rigid post op dressing with early ambulation Type of amputations Symes 20
Amputation principles BIOMECHANICS AVOID ABNORMAL SHAPES AVOID EQUINO-VARUS DEFORMITY BELOW KNEE AMPUTATION DESIGN IS KEY 1) Posterior flap design 2) Cut tibia 10-12 cm from tubercle 3) Bevel anterior tibial bone 4) Tenodese Achilles to anterior tibial bone 5) Shape posterior flap for funneled stump 21
Patient Support and Education Community lecture series Amputee support group Probability of wound healing Etiology of wound History and exam Vascular lab Need for revascularization? Clinical course Toe pressures, TcO2, SPP Type of revascularization Endovascular therapy Surgical bypass Wound care 22
Thank you 23