Staging the Neuro-Ischemic Limb - Rutherford, WiFi, and other Approaches - Critical Limb Ischemia. Staging of the Ischemic Limb - PAD

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1 Staging the Neuro-Ischemic Limb - Rutherford, WiFi, and other Approaches - Dennis F. Bandyk, MD Vascular & Endovascular Surgery Sulpizio Cardiovascular Center UCSF Symposium April 18, Staging of the Ischemic Limb - PAD Classification Scheme Fontaine - introduced in 1954 III - Ischemic rest pain IV - Ischemic ulcer or gangrene Limb Perfusion Rutherford - Category 4: Ischemic rest pain TP<30 mm Hg Category 5: Tissue loss AP<60 mm Hg; TP<40 mm Hg Category 6: Major tissue loss, Same as Category 5 non-salvagable foot Prevent III Risk Score predict amputation-free survival from 5 clinical variables SVS Threatened Lower Limb WIfI Risk stratification is based on three factors that impact amputation risk Wound, Ischemia, and foot Infection (WIfI). Assessment of Foot Perfusion Critical Limb Ischemia Concept defined in 1982 by an expert consensus panel* - a limb threatening condition - rest pain: ankle pressure <50 mm Hg - superficial tissue loss/toe gangrene: ankle pressure <60-70 mm Hg TODAY - CLI recognized as an advanced stage of PAD with an associated increased risk of limb loss & cardiovascular mortality new cases /yr/million in US and Europe BUT the CLI definition is not valid to the diabetic patient with a with foot lesion with a threatened limb because of Neuropathy Ischemia - PAD Infection sepsis *Bell PRF et al. The definition of critical limb ischemia Br J Surg

2 CLI Limb Amputation Free Survival Circulase trial (prostaglandin) pts with ischemic rest pain and tissue loss 6 mo. in the placebo arm was 13% Concept of the NeuroIschemic Limb The diabetic foot ulcer (DFU) is a limb threatening condition The combination of DFU + PAD (ABI<0.8) triples the risk of amputation JVS 2011 : 1151 consecutive pts - DFU & toe pressure < 45 mm Hg Outcome: Ulcer healing achieved in 72% of pts. 52% wound healing rate 23% major amputation rate at 12-mo. Recommendation: a more accurate classification system for CLI patient regarding amputation risk is necessary to provide a more meaningful analysis of outcomes J Vasc Surg 2008;48: ) 2

3 Amputation Risk Disease Burden Wound: Ulcer - nonhealing lesion of least 2 weeks duration; three Grades based on depth Gangrene tissue loss involving any portion of the foot or leg Ischemia 4 grades based on ABI Amputation Risk at 1-yr 3% 10 % 23% 40% Rest pain, typically in the forefoot with confirmed hemodynamic studies (ABI<0.40,AP<50,TP<30; TcpO2<20) Foot Infection 3 grades patients with foot wounds and ischemia consecutive patients with threatened limbs J Vasc Surg 2015;61: ) 90% of amps Conclusions: The theoretical framework for risk stratification among patients with critical limb ischemia provided by the SVS expert panel appears valid. (J Vasc Surg 2014;60: ) 3

4 Diabetic man with 1 st toe ulcer Angiosome Directed Revascularization Associated with 2x ulcer healing rate (72% vs 45% Target Foot Perfusion Testing AT balloon angioplasty No PAD Hyperspectral Imaging PAD Indocyanine Green Angiography - application or angiosome-directed revascularization Spatial Maps of Tissue Oxygenation May identify skin perfusion abnormalities in diabetics Predict ulcer healing 4

5 Multimodal Assessment of Limb Perfusion Left Iliac Stent Thrombosis Left 1 st toe pressure 29 mm Hg Spect CT Scan hybrid 99mTc-tetrofosmin demonstrating decreased Left limb perfusion DP at ankle level SUMMARY Staging of CLI is important for patient counseling and assessment of new therapies, including angiogenesis Recommended outcome measure: amputation-free survival Revascularization for CLI involves procedure and best artery selection for bypass or angioplasty. But despite revascularization, nonhealing rates of 18% of higher occur; resulting in amputation due to infection Current research suggests the angiosome model & targeted revascularization approach may provide better results wound healing sates and limb salvage. Thank You for Your Attention Regional foot perfusion modalities - TcPO2, hyperspecteral imaging, Indocyanine green angiography, laser Doppler may help guide angiosome directed revascularization of CLI and angiogenetic therapy 5