Predictors of Surgical Site Infection After Surgery for Infrainguinal Occlusive Disease: Results From the National Surgical Quality Improvement Program

OBJECTIVE: Surgical site infection (SSI) after open surgery for infrainguinal occlusive disease (IOD) is a serious complication that may lead to graft infection, prolonged hospitalization, and increased cost. Rates of SSI after revascularization vary widely, with most studies reported from single institutions. The objective of this study was to describe on a national scale the rate and predictors of SSI after surgery for IOD, and to identify any association between SSI and length of hospital stay, reoperation, graft loss, and mortality.
METHODS: Patients who underwent infrainguinal arterial bypass or endarterectomy from 2005-2008 were identified from the American College of Surgeons National Surgical Quality Improvement Project (ACS NSQIP) Participant Use Data Files. Multivariate logistic regression identified predictors of SSI. Odds ratios were adjusted for patient demographics, comorbidities, pre-operative laboratory values, and operative variables.
RESULTS: Of 10,993 patients who underwent open surgery for IOD, 1,247 (11.3%) were diagnosed with an SSI within 30 days. By multivariate analysis, significant predictors of SSI included female gender, obesity, steroid use, pre-operative leukocytosis, and length of operation greater than four hours. SSI was associated with prolonged (>10 days) hospital stay (adjusted OR 1.8, 95% CI 1.4-2.1) and higher rates of 30-day graft loss (adjusted OR 2.3, 95% CI 1.7-3.1) and reoperation (adjusted OR 3.7, 95% CI 3.1-4.6). SSI was not associated with increased 30-day mortality.
CONCLUSIONS: SSI remains a significant complication after open revascularization for IOD. SSI was associated with a more than two-fold increased risk of early graft loss and reoperation. Several patient and operation-related risk factors that predict postoperative SSI were identified, suggesting that targeted improvements in peri-operative care may decrease complications and improve outcomes in this patient population.