Impact of Wound Closure Technique on Surgical Site Infection after Lower Extremity Bypass Surgery

Abstract

Surgical site infections (SSI) are among the most common complications after lower extremity bypass (LEB). Both patient and hospital-related factors have been associated with SSI after LEB, however, the impact of surgical closure technique on SSI incidence remains unclear. Institutional electronic medical records were retrospectively queried for all LEB procedures performed from 2018 through 2022. Data were collected on patient demographics, medical comorbidities, operative details, wound closure techniques, and postoperative outcomes. Closure techniques included skin staples, absorbable monofilament (Monocryl), non-absorbable monofilament (Nylon), or left open to heal by secondary intention. Logistic regression analysis was utilized to identify risk factors and calculate adjusted odds ratios (OR) for postoperative SSI. A total of 517 patients underwent LEB surgery over the study period. SSI was diagnosed in 120 (23.2%) patients over a median follow-up period of 1.5 years. The most common SSI locations were groin incision (40.0%), saphenectomy (31.7%), and leg incision (19.2%). Median onset of SSI was 18.5 d (interquartile range [IQR] 11-28 d) post-LEB surgery. Patients with SSI had higher body mass index (BMI) (28.2 [IQR 24.2-33.5] vs 26.6 [23.1-31.5] kg/m2, p=0.03) compared with non-SSI patients. Patient age, sex, and medical comorbidities were otherwise similar between groups. There were no differences in closure technique (79.2% vs 78.1% staples, 18.3% vs 19.7% Monocryl, 0.8% vs 1.8% Nylon, 1.7% vs 0.5% open; p=0.53) in SSI versus non-SSI groups. On multivariate analysis, patient BMI (OR 1.04 per unit, 95% confidence interval [CI] 1.01-1.08, p=0.02), reoperative field (OR 1.81, 95% CI 1.00-3.25, p=0.03), and active smoking (OR 2.72, 95% CI 1.12-6.59, p=0.048) were independently associated with increased SSI incidence. Postoperative SSI resulted in prolonged hospital length of stay (7 vs 6 days, p=0.04), unplanned hospital readmission (49.2% vs 12.3%, p<0.001), and reoperation rates (64.7% vs 8.1%, p<0.001). Bypass graft infection rates were also higher among patients suffering postoperative SSI (9.2% vs 0.0%, p<0.001). On subset analysis of patients at increased risk of postoperative SSI, as found on multivariate modelling, there were no differences in closure technique between SSI and no SSI groups. This study provides insights on wound closure techniques and postoperative SSI made available through granular, operative data not found in large database analyses. Surgical wound closure technique was not associated with postoperative SSI after LEB surgery, even among patients at increased risk of infection. These data support individualization of wound closure techniques among patients undergoing LEB surgery.