Active smoking in claudicants undergoing lower extremity bypass predicts decreased graft patency and worse overall survival

Abstract

Objective: Performing lower extremity bypass (LEB) in actively smoking claudicants remains controversial. Whereas some surgeons advocate a strict nonoperative approach to active smokers, citing perceived inferior outcomes, others will proceed with surgical bypass if the patient is anatomically suited and medical management has failed. The purpose of this study was to determine the impact of active smoking on LEB outcomes among claudicants.

Methods: All patients undergoing infrainguinal LEB for claudication in the Vascular Study Group of New England from 2003 to 2016 were analyzed. Smoking was defined as active tobacco use within 1 month of surgery. End points included in-hospital outcomes; long-term primary, assisted primary, and secondary patency; and mortality. Univariate, Cox multivariable, and Kaplan-Meier methods were used to determine the impact of smoking. Propensity score matching was performed to control for intergroup differences.

Results: Of 1789 LEBs, 971 (54%) were performed in nonsmokers and 818 (46%) in smokers. The follow-up rate was 87% at a mean of 382 days (standard error, ±6.8 days). Smokers were younger (60 vs 68 years; P < .001) and were less likely to have multiple comorbidities, including hypertension, coronary artery disease, congestive heart failure, diabetes, and chronic renal insufficiency (P ≤ .05); they were more likely to have an above-knee popliteal bypass target (52% vs 43%; P = .001). Smokers also had lower rates of postoperative major cardiac events (2.4% vs 5.3%; P = .002) and perioperative blood transfusion (5.6% vs 11%; P < .001) compared with nonsmokers, but there was no difference in respiratory complications, wound complications, or mortality. At 2-year follow-up, smokers demonstrated inferior primary patency (48% vs 61%; P = .03) and assisted primary patency (59% vs 74%; P = .01), with comparable rates of secondary patency and overall mortality. Propensity matching yielded two similar groups (n = 450 for each). Propensity-matched smokers had significantly decreased 2-year primary patency (43% vs 58%; P = .02), assisted primary patency (54% vs 71%; P = .03), and 10-year survival (69% vs 76%; P < .01). Cox multivariable analysis confirmed that smoking was an independent predictor of diminished primary patency (hazard ratio [HR], 1.3; 95% confidence interval [CI], 1.0-1.6; P = .03), assisted primary patency (HR, 1.4; 95% CI, 1.1-1.8; P = .004), and overall survival (HR, 1.3; 95% CI, 1.1-1.5; P < .001).

Conclusions: Despite the fact that smokers are younger and have fewer comorbidities than nonsmokers, active smoking at the time of LEB for claudication is associated with decreased long-term patency and decreased overall survival. Surgeons should consider smoking an important risk factor for worse LEB outcomes in smokers compared with nonsmokers.