PC158. The Impact of Achieving a Normal Ankle-Brachial Index on Patency and Limb Salvage After Lower Extremity Bypass

Abstract

The ideal result of infrainguinal bypass (IBP) with in-line flow to the foot should be a normal hemodynamic result indicated by a palpable pulse/normal ankle-brachial index (ABI). The results of intervention can vary depending on inflow and outflow of the bypass and the quality and type of conduit chosen. The object of this study is to identify outcome depending on the hemodynamic result after IBP. National Vascular Quality Initiative (VQI) data from 2003 to 2017 were queried to identify patients with CLI and claudication treated with IBP with primary patency at 1 year. The outcome of interest was maintenance of ABI between 0.9 and 1.3 (normal ABI) at 1 year. Exclusions included patients with noncompressible tibial vessels, those without postoperative ABI and 1 year follow-up, and those with prior ipsilateral infrainguinal endovascular intervention or IBP. Of a total of 37,970 patients, 1519 met our selection criteria. Cohorts perfusion grade were: ABIs 0 to 0.5, (n = 206), ABIs 0.5 to 0.9 (n = 665), and ABIs 0.9 to 1.3 (n = 648; Table I). Demographics and procedural factors were evaluated for predictors of failure to maintain unassisted normal ABI at 1 year using multivariable logistic regression. Stepwise regression was used for variables with P < .2 from χ2 or t test analysis. Of the 648 patients with a normal ABI at discharge, 79.6% maintained a normal ABI at one year follow-up, and 2 patients underwent major amputation. When discharged with an ABI of <0.9, 54.7% had a subsequent ABI measured at >0.9 at the 1-year follow-up and a total of six major amputations occurred. In patients with a normal ABI at discharge, multivariable analysis demonstrated that any history of nonindex limb peripheral vascular intervention, coronary artery disease, concomitant endarterectomy, diabetes, pedal bypass target, postoperative congestive heart failure, or sequential graft were predictive of a drop in ABI at 1 year to <0.9. (Table II). The discharge ABI 0.5 to 0.9 cohort multivariable analysis showed that hypertension, female gender, postoperative myocardial infarction, and nonwhite race were predictive of poor hemodynamic result; use of vein conduit and preop ABI grade were protective of a maintained ABI at the 1-year follow-up (Table II). These results suggest that patients with a normal ABI immediately after bypass have a high likelihood of maintaining a normal hemodynamic response at one year, irrespective of conduit choice. However, conduit type, among other factors, becomes important when postoperative perfusion results are not optimal.Table IDemographics, risk factors, and conduit typesVariableDischarge ABI 0.9 to 1.3Discharge ABI 0.5 to 0.9LTF ABI 0.9 to 1.3LTF ABI < 0.9PLTF ABI 0.9 to 1.3LTF ABI < 0.9PAge (mean ± SD)64.66 ± 11.465.54 ± 100.41765.45 ± 10.266.66 ± 9.9.122Female gender137 (26.6%)43 (32.6%)0.172102 (28%)121 (40.2%).001Non-white58 (11.2%)15 (11.4%)0.96841 (`%)51 (16.9%).035Hispanic/Latino15 (2.9%)6 (4.5%)0.3565(1.4%)5 (1.7%).776Chronic obstructive pulmonary disease105 (20.3%)29 (22%)0.68190 (24.7%)76 (25.2%).877Hemodialysis8 (1.6%)6 (4.5%)0.0357 (1.9%)5 (1.7%).801Diabetes mellitus161 (31.2%)63 (47.7%)<.001151 (41.5%)148 (49.2%).047Coronary artery disease115 (22.3%)43 (32.6%)0.014107 (29.4%)104 (34.6%).163Hypertension422 (81.8%)112 (84.8%)0.409307 (84.3%)285 (94.7%).0001Smoking445 (86.2%)114 (87%)0.815328 (90.1%)267 (88.7%).557Critical limb ischemia284 (55%)77 (58.3%)0.497215 (59.1%)196 (65.1%).110Vein graft339 (65.7%)88 (66.7%)0.834280 (76.9%)195 (64.8%).001Vein graft type0.658.011 Reverse GSV156 (30.2%)31 (23.7%)112 (30.8%)68 (22.6%) In situ GSV86 (16.7%)27 (20.6%)92 (25.3%)3 (24.3%) Nonreverse GSV80 (15.5%)25 (19.1%)68 (18.7%)42 (14%) LS4 (0.8%)0 (0%)0 (0%)1 (0.3%) Cephalic7 (1.4%)3 (2.3%)2 (0.5%)2 (0.7%) Basilic3 (0.6%)1 (0.8%)0 (0%)1 (0.3%) Composite3 (0.6%)1 (0.8%)6 (1.6%)8 (2.7%) Prosthetic177 (34.3%)44 (33.6%)84 (23.1%)106 (35.2%)Vein segments, No.0.383.005 1319 (62.1%)81 (61.4%)258 (70.9%)176 (58.5%) ≥213 (2.5%)7 (5.3%)14 (3.8%)14 (4.7%)GSV, Great sapehnous vein. Open table in a new tab Table IIMultivariate logistic regression: Significant resultsDC ABIOR95% CI for ORPLowerUpper0.9-1.3 History of peripheral vascular intervention2.0421.2213.414.007 Postoperative minor amp0.1450.0320.651.012 Coronary artery disease1.7811.0592.996.030 Concomitant endarterectomy1.9791.2313.183.005 Diabetes1.9841.2293.202.005 Pedal target5.9761.85119.289.003 Postoperative congestive heart failure5.5911.09428.575.039 Sequential graft5.5501.26824.283.0230.5-0.9 Hypertension2.9091.5635.412.001 Female1.8411.2822.644.001 Vein graft0.5870.4000.860.006 New myocardial infarction3.0481.2157.644.018 Preoperative ankle-brachial index grade0.6820.4890.950.024 Nonwhite1.8141.0973.000.020 Open table in a new tab