Global Vascular Guideline on the Management of Chronic Limb Threatening Ischemia -a new foundation for evidence-based care

Transcription

1 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

2 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(SVS), and the World Federation of Vascular Societies () Definitions: CLTI The term critical limb ischemia (CLI) is outdated and fails to encompass the full spectrum of patients who are evaluated and treated for limb-threatening ischemia in modern practice Instead, the term chronic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. 2

3 CLTI: criteria for diagnosis Objectively documented atherosclerotic PAD Ischemic rest pain typically described as pain in the mid- and forefoot at rest, often worse with recumbency and relieved by dependency, present for more than 2 weeks ABPI <0.4 (using higher of the DP / PT) Absolute highest ankle pressure <50 mmhg Absolute toe pressure <30 mmhg TcP02 <20 Torr Flat pulse volume recording waveforms Tissue Loss diabetic foot ulcer, nonhealing lower limb or foot ulceration of at least 2 weeks duration, any gangrene WIfI ischemia score 1 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 3

4 Need for Structured Decision Making in CLTI PLAN: Patient Risk Limb threat severity: WIfI Staging Anatomic pattern of disease: GLASS system 4

5 Risk stratification tools High Risk defined as expected perioperative mortality >5% OR expected 2 year survival <50% 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 5

6 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. 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 2 Major tissue loss: deeper ulceration(s) with exposed bone, joint or tendon, ulcer 5 10 cm 2 not involving calcaneus (Pedis or UT Classes 2 and 3); gangrenous changes limited to digits. Salvageable with multiple digital amps or standard TMA + skin coverage 3 Extensive ulcer/gangrene > 10 cm 2 involving forefoot or midfoot; full thickness heel ulcer > 5 cm 2 + calcaneal involvement. Salvageable only with complex foot reconstruction, nontraditional TMA (Chopart/Lisfranc); flap coverage or complex wound management needed 6

7 Ischemia Grade Noninvasive Assessment Grade ABI Ankle SP TP 0 > 0.80 > 100 mm Hg > 60 mm Hg mmhg mm Hg mm Hg mm Hg 3 < 0.40 < 50 mm Hg < 30 mm Hg ABI=ankle brachial index; SP= systolic pressure; TP=toe pressure 7

8 Risk of Amputation Benefit of Revascularization? Note: These are NOT Concordant There Is a Free App for That: 8

9 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): (3%) 63 (10%) 43 (23%) 8 (40%) Zhan (2015): (0%) 50 (0%) 53 (8%) 59 (64%)* Darling (2015): (0%) 111 (10%) 222 (11%) 213 (24%) Causey (2016): (0%) 48 (8%) 42 (5%) 49 (20%) Beropoulis (2016): (0%) 42 (2%) 29 (3%) 26 (12%) Ward (2016): 98 5 (0%) 21 (14%) 14 (21%) 58 (34%) Darling (2017): (0%) 293 (4%) 249 (4%) 438 (21%) Robinson (2017): (4%) 67 (16%) 64 (10%) 83 (22%) Mathioudakis (2017): (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 9

10 Benefit of revascularization varies with severity of limb threat and ischemia 3 N/A High benefit Severity of Ischemia (WIfI Ischemia Grade) N/A Low/Nil benefit 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 10

11 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 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 angiosomebased 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) 11

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13 GLASS: Consensus Staging of TAP Complexity for Endovascular Intervention 13

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

15 FP grading: Total length of SFA disease: 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

16 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

17 FP grading: SFA: no significant stenosis Popliteal: CTO extending into trifurcation FP grade = 4 IP grading: TAP = ATA ATA: CTO target artery origin IP grade = 3 GLASS Stage = III Factors Determining Clinical Success Differ High patient risk More severe limb threat (e.g. WIfI Stage 4) Greater target lesion/path complexity of occlusive disease Prior failed implant Poor runoff Good quality vein available Good quality vein not available FAVORS MORE Bypass Endo

18 Preferred initial revascularization strategy for infrainguinal disease, in average risk CLTI patients with adequate autogenous vein for bypass Anatomic Complexity (GLASS Stage) III II I Open Bypass Indeterminate Endovascular No Revascularization Limb Severity (WIfI Stage) 18

19 Funded by NHLBI in 2013 Compare initial Endo vs initial Bypass in CLI Parallel trial, stratified design Target 2100 patients, approximately 120 centers Current enrollment approximately 900 BASIL 2 (BTK) Bypass versus Angioplasty / Stenting in Severe Ischaemia of the Leg due to BTK Disease Trial Andrew W. Bradbury Sampson Gamgee Professor of Vascular Surgery University of Birmingham, UK Heart of England NHS Foundation Trust, Birmingham, UK 19

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