National Utilization and Outcomes of Redo Lower Extremity Bypass versus Endovascular Intervention after a Previous Failed Bypass

Abstract

Background: Redo lower extremity bypass (LEB) and infrainguinal endovascular intervention (IEI) are options to treat critical limb ischemia after a failed prior LEB, but the utilization and outcomes of each are poorly described. The purpose of this study was to compare 30-day major adverse limb events (MALEs) and major adverse cardiovascular events (MACEs) after LEB and IEI in patients with a failed prior ipsilateral LEB and determine risk factors for each composite outcome.

Methods: Patients with prior failed ipsilateral LEB who underwent LEB or IEI involving the same arterial segment for critical limb ischemia were identified in the National Surgical Quality Improvement Program (NSQIP) Vascular Targeted File (2011-2014). LEB with single-segment saphenous vein was compared to LEB with alternative conduit (prosthetic/spliced vein/composite) and IEI. Primary outcomes were MALE (untreated loss of patency, reintervention, or amputation) and MACE (stroke, myocardial infarction, or death). Multivariate analysis was utilized to identify independent predictors of MALE and MACE.

Results: Among 8,066 revascularizations performed for critical limb ischemia (CLI), 1,606 (461 [28.7%] IEI, 518 [32.3%] LEB saphenous, and 627 [39.0%] LEB alternative) were performed after failed ipsilateral LEB involving the same arterial segment. LEB with saphenous had lower MALE than LEB with alternate conduit and IEI (15.8% IEI, 10.8% saphenous, and 15.5% alternative, P = 0.03). Higher MALE was driven by higher 30-day amputation in IEI (7.8% IEI, 3.7% saphenous, and 5.3% alternative, P = 0.02). Independent predictors of MALE include transfer status (odds ratio [OR] = 1.7, P = 0.01), tobacco use (OR = 1.5, P = 0.02), infrageniculate revascularization (OR = 1.6, P = 0.004), and saphenous conduit (OR = 0.5, P = 0.002). MACE was also different between groups (3.9% IEI, 7% saphenous, and 5.6% alternative, P = 0.049), with no difference in 30-day mortality (P = 0.53). Independent predictors of MACE included congestive heart failure (OR = 3.0, P = 0.01) and dialysis dependence (OR = 2.5, P = 0.02).

Conclusions: In this large national sample representing routine vascular care of patients with CLI after failed ipsilateral LEB of the same arterial segment, IEI is common and represents 30% of revascularizations in this data set. Redo LEB with saphenous is associated with superior limb-related outcomes, but IEI offers an acceptable potential alternative to bypass in patients who would require alternative conduit. Finally, perioperative care is critical as we demonstrate that patient comorbidities, not the method of revascularization, predicted MACE.