Disclosures Co-editor, Global Vascular Guidelines Writing Group - PDF document

4/17/2018 Global Vascular Guideline on the Management of Chronic Limb Threatening Ischemia -a new foundation for evidence-based care Michael S. Conte MD Professor and Chief, Division of Vascular and Endovascular Surgery Disclosures • Co-editor, Global Vascular Guidelines Writing Group • Abbott Vascular (advisory board) • Symic, Inc. (advisory board) UCSF Vascular Symposium 2018: Global Vascular Guidelines on CLTI 1

4/17/2018 The Global Vascular Guidelines (GVG) initiative is sponsored by an international consortium of vascular societies, led by the European Society for Vascular Surgery (ESVS), the Society for Vascular Surgery (SVS), and the World Federation of Vascular Societies (WFVS) WFVS Definitions: CLTI The term critical limb ischemia (CLI) is outdated and fails to encompass the full spectrum of patients who are evaluated and treated for limb-threatening ischemia in modern practice Instead, the term chronic limb-threatening ischemia (CLTI) is proposed, in order to include a broader and more heterogeneous group of patients with varying degrees of ischemia that can often delay wound healing and increase amputation risk. WFVS 2

4/17/2018 CLTI: criteria for diagnosis Objectively documented atherosclerotic PAD Ischemic rest pain typically described as Tissue Loss diabetic foot ulcer, non- pain in the mid- and forefoot at rest, often healing lower limb or foot ulceration of worse with recumbency and relieved by at least 2 weeks duration, any dependency, present for more than 2 weeks gangrene ABPI <0.4 (using higher of the DP / PT) WIfI ischemia score ≥1 Absolute highest ankle pressure <50 mmHg Absolute toe pressure <30 mmHg TcP02 <20 Torr Flat pulse volume recording waveforms WFVS CLTI: exclusions • Absence of any significant PAD, eg, WIfI ischemia grade=0 • May be unique circumstances of impaired local perfusion (angiosome) not reflected by the WIfI ischemia grade for the limb as a whole • Lower extremity wounds that are a direct result of acute trauma • Ulcers of primarily venous origin • Acute limb ischemia (onset ≤ 14 days) • Impaired tissue perfusion related to non-atherosclerotic conditions WFVS 3

4/17/2018 Need for Structured Decision Making in CLTI  PLAN:  P atient Risk  L imb threat severity: WIfI Staging  An atomic pattern of disease: GLASS system WFVS WFVS 4

4/17/2018 Risk stratification tools High Risk defined as expected perioperative mortality >5% OR expected 2 year survival <50% WFVS Importance of Limb Staging in CLTI  Broad spectrum of complexity and risk for limb loss  Complicates analysis of outcomes and treatment decisions  Previous classification systems inadequately capture the full range of neuro-ischemic compromise  Fallacy of a specific hemodynamic threshold for “critical” ischemia  SVS Wound, Ischemia, Foot Infection (WIfI) system  Characterizes each of the three major components  Grouped into 4 stages based on estimated risk for limb loss  Multiple validation reports WFVS 5

4/17/2018 Definitions: WIfI • WIfI stratifies amputation risk according to the Wound , the degree of Ischemia , and presence and severity of foot Infection • WIfI scores and clinical stages appear to strongly correlate with important clinical outcomes, including those included in SVS Objective Performance Goals (OPG): limb amputation, 1‐year amputation free survival, and wound healing time • WIfI is currently being evaluated in • Multi‐center trials in the US • UK NIR HTA‐funded BASIL‐2 and BASIL‐3 trial • SVS VQI (Vascular Quality Initiative) Registry of lower extremity interventions . WFVS Wound Grade – Clinical Category Grade Clinical Description 0 Ischemic rest pain; Pre‐gangrenous skin change, without frank ulcer or gangrene (Pedis or UT Class 0) 1 Minor tissue loss: small shallow ulceration) < 5 cm 2 on foot or distal leg (Pedis or UT Class 1); no exposed bone unless limited to distal phalanx Major tissue loss: deeper ulceration(s) with exposed bone, joint or tendon, ulcer 5‐10 cm 2 not 2 involving calcaneus – (Pedis or UT Classes 2 and 3); gangrenous changes limited to digits . Salvageable with multiple digital amps or standard TMA + skin coverage Extensive ulcer/gangrene > 10 cm 2 involving forefoot or midfoot; full thickness heel ulcer > 5 3 cm 2 + calcaneal involvement. Salvageable only with complex foot reconstruction, nontraditional TMA (Chopart/Lisfranc); flap coverage or complex wound management needed WFVS 6

4/17/2018 Ischemia Grade – Noninvasive Assessment Grade ABI Ankle SP TP 0 > 0.80 > 100 mm Hg > 60 mm Hg 1 0.60‐0.79 70‐99 mmHg 40‐59 mm Hg 2 0.40‐0.59 50‐69 mm Hg 30‐39 mm Hg 3 < 0.40 < 50 mm Hg < 30 mm Hg ABI=ankle brachial index; SP= systolic pressure; TP=toe pressure WFVS WFVS 7

4/17/2018 Risk of Amputation Benefit of Revascularization? Note: These are NOT Concordant There Is a Free App for That: https://itunes.apple.com/app/id1014644425 8

4/17/2018 Risk of amputation versus WIfI Stage: Compilation of published data Study (year): # Limbs at Risk Stage 1 Stage 2 Stage 3 Stage 4 Cull (2014):151 37 (3%) 63 (10%) 43 (23%) 8 (40%) Zhan (2015): 201 39 (0%) 50 (0%) 53 (8%) 59 (64%)* Darling (2015): 551 5 (0%) 111 (10%) 222 (11%) 213 (24%) Causey (2016): 160 21 (0%) 48 (8%) 42 (5%) 49 (20%) Beropoulis (2016): 126 29 (0%) 42 (2%) 29 (3%) 26 (12%) Ward (2016): 98 5 (0%) 21 (14%) 14 (21%) 58 (34%) Darling (2017): 992 12 (0%) 293 (4%) 249 (4%) 438 (21%) Robinson (2017): 262 48 (4%) 67 (16%) 64 (10%) 83 (22%) Mathioudakis (2017): 279 95 (6.5%) 33 (6%) 87 (8%)** 64 (6%)*** N = 2820 (weighted mean) 291 ( 3.2% ) 728 ( 6.8% ) 803 ( 8.5% ) 998 ( 24% ) Median (% 1 year amputation) 0% 8% 8% 22% Limb staging and appropriateness of revascularization • CLTI represents a range of limb severity and ischemia as described in WIfI staging. • Severe ischemia (WIfI ischemia grade 3) mandates revascularization for limb salvage • With increased stages of limb threat (WIfI stages 3, 4) moderate degrees of ischemia (grades 1, 2) may be appropriate to address • Low risk limbs (WIfI Stage 1) should be treated with wound care; revascularization should be reserved for failure to heal (50% within 4‐ 6 weeks) or clinical signs of deterioration • Not indicated for Ischemia grade 0 WFVS 9

4/17/2018 Benefit of revascularization varies with severity of limb threat and ischemia 3 High benefit N/A (WIfI Ischemia Grade) Severity of Ischemia 2 Low/Nil benefit N/A 1 0 1 2 3 4 Limb Severity (WIfI Stage) Rationale for a new anatomic staging system in CLTI • Schemes focused on individual lesions (e.g. TASC) or overall burden of disease (e.g. Bollinger) are not useful for defining evidence-based revascularization in CLTI • Restoration of in-line flow to the foot is a primary technical goal of revascularization in CLTI, particularly in patients with tissue loss • Factors that determine clinical success for endovascular and open bypass surgery are intrinsically different WFVS 10

4/17/2018 GLASS*: Assumptions and Approach • Focus on Infrainguinal Disease (SFA origin to foot) • Clinician defines the primary Target Artery Path (TAP) • Femoro-popliteal (FP) and Infra-popliteal (IP) segments separately graded (0-4), then combined into Three GLASS Stages for the limb (I-III) • Infra-malleolar (pedal) disease graded; used as a modifier only • Calcification graded as Severe or not; simplified system • * Global Limb Anatomic Staging System WFVS GLASS: Target Artery Path and Limb-Based Patency • Restoration of in‐line flow to the ankle and foot is a primary goal • Target artery path (TAP): the selected continuous route of in‐line flow from groin to ankle • TAP usually involves the least diseased IP artery; may be angiosome‐ based • Limb‐based patency (LBP ): maintained patency of the TAP. Lost when: • Occlusion, critical stenosis, or re‐intervention affecting any portion of the TAP ( anatomical failure ), and/or: • Fall in ABI (≥ 0.15) or TBI (≥ 0.10), or ≥ 50% stenosis in the TAP, in the presence of recurrent or unresolved clinical symptoms (e.g. rest pain, worsening/persistent tissue loss; signifying hemodynamic failure ) WFVS 11

4/17/2018 WFVS WFVS 12

4/17/2018 GLASS: Consensus Staging of TAP Complexity for Endovascular Intervention WFVS 13

4/17/2018 Pedal disease modifier not included in overall limb stage assignment at present due to insufficient data on relationship to treatment outcomes WFVS Examples of the GLASS system 14

4/17/2018 FP grading: Total length of SFA disease: 10‐20 cm Popliteal disease: <5cm does not involve trifurcation Calcification + 1 FP grade = 4 IP grading: TAP= peroneal artery Peroneal: stenosis TP trunk IP grade = 2 GLASS Stage = III 15

4/17/2018 FP grading: SFA single stenosis/occlusion approx 5 cm Popliteal: no significant stenosis FP grade = 1 IP grading: TAP = ATA ATA: 2 focal stenosis, <1/3 (<10cm) IP grade = 2 GLASS Stage = II FP grading: SFA: no significant stenosis Popliteal: no significant stenosis FP grade = 0 IP grading: TAP = peroneal artery Peroneal: CTO 3‐10cm IP grade = 3 GLASS Stage = II 16