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CLINICAL STATEMENTS AND GUIDELINES

Circulation. 2024;149:e1313–e1410. DOI: 10.1161/CIR.0000000000001251 June 11, 2024 e1361

when clinically indicated, is more appropriate (see Section 10.3.4, “Amputation for CLTI”).

Revascularization Strategy for CLTI

3 Many large RCTs and observational studies have

shown that bypass to the popliteal artery should be constructed with autogenous vein, either reversed or in situ.14–20 Large single-center trials and registry data have shown superior efficacy of autogenous vein to prosthetic conduit in bypass to infrapopliteal arteries.38,39,46 Although single-segment great saphenous vein is the preferred conduit, bypass grafts constructed with small saphenous and arm (ie, basilic or cephalic) veins have been shown in single-center studies to have durable patency in the absence of autogenous great saphenous vein.47,48 In addition, when single-segment autogenous vein is unavailable, use of a composite bypass conduit (ie, conduit derived from multiple different vein segments) as well as bypass to an isolated popliteal arterial segment that has collateral outflow to the foot (as a mechanism to utilize a shorter segment of vein) are both acceptable methods of revascularization and should be considered.49,50

4 Two recently published and seminal RCTs have

addressed whether the first revascularization strategy for a patient with CLTI should be endovascular intervention or surgical bypass.3,13 The BEST-CLI trial enrolled patients with infrainguinal, with or without infrapopliteal, disease who were candidates for both surgical bypass and endovascular revascularization, where high-quality great saphenous vein was available (Cohort 1), or where alternative conduits were necessary to complete surgical bypass (Cohort 2).3 This study found that for patients with available single-segment saphenous vein (Cohort 1), the composite outcome of death from any cause or MALE (defined as a major amputation above the ankle, new bypass graft, graft thrombectomy, graft revision, or thrombolysis) occurred in 32% fewer patients randomized to surgical bypass (302 events/709 patients, 42.6%) than to endovascular revascularization (408 events/711 patients, 57.4%) at a median of 2.7 years of follow-up (HR: 0.68 [95% CI: 0.59-0.79]; P<0.001).3 The difference was driven by higher rates of repeat revascularization in the endovascular group. The group without adequate great saphenous vein (Cohort 2) did not meet prespecified enrollment targets to achieve statistical power, and no observed difference was observed in the rate of the composite outcome of death or MALE (HR: 0.79 [95% CI: 0.58-1.06]; P=0.12) between endovascular revascularization (95 events/199 patients, 47.7%) and surgical bypass (83 events/194 patients, 42.8%).3 In the BASIL-2 (Bypass versus Angioplasty for Severe Ischaemia of the Leg) trial, which studied patients with infrapopliteal with or without more proximal infrainguinal disease, major amputation or death occurred more often after bypass treatment (108 events/172 patients, 63%) than endovascular (92 events/173 patients, 53%) (adjusted HR: 1.35 [95% CI: 1.02-1.80]; P=0.037).13 This difference was driven by fewer deaths in the endovascular treatment group. The contrasting findings of the BEST-CLI and BASIL-2 trials highlight the need to consider patient clinical and anatomic characteristics when selecting the initial revascularization strategy for patients with CLTI, including consideration of patient risk estimation, staging of the limb for severity and anatomic pattern of disease, previous vascular interventions, and availability of conduit. Examples of potential factors in selecting revascularization strategy in patients with CLTI are summarized in Table 16. The Global Vascular Guidelines reviewed available data on management of CLTI and recommended the use of evaluation tools that consider wound perfusion, infection, and extent of the tissue loss.51,52 The Global Limb Anatomic Staging System (GLASS) can be incorporated into the decision-making process for revascularization.53 A patient-centered decisionmaking process around revascularization strategy for CLTI should also incorporate patient goals and preferences, input of the multidisciplinary care team, and risk-benefit calculation. 5.	 Multiple studies have demonstrated improved

patency of femoral-popliteal bypasses when constructed with autogenous vein, and the great saphenous vein is the optimal venous conduit for femoral-popliteal bypass.51,54,55 In the BEST-CLI trial, the presence or absence of a 3-mm diameter great saphenous vein was the criterion used to determine adequacy of this conduit for surgical bypass.3 The protocol in BASIL-2 stated that vein conduit had to be deemed “suitable” to accomplish surgical bypass, or alternative conduits would be used, a circumstance that occurred in 7% of trial patients.13 Preoperative assessment of the adequacy of the great saphenous vein conduit is important when developing a patient-specific revascularization strategy for CLTI (Table 16). Great saphenous vein evaluation, also known as “vein mapping,” is generally performed in a vascular laboratory using duplex ultrasound. This test includes assessment of vein patency, size (vein diameter), length of available vein, and other anatomic features such as branching and presence of acute or previous thrombosis. Ultrasound mapping can also be used, if necessary, to assess other potential venous conduits, including the small saphenous and upper extremity (eg,

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