Harvest surgical site infection following coronary artery bypass grafting: Risk factors, microbiology, and outcomes

Background: Our goals were to evaluate the risk factors predisposing to saphenous vein harvest surgical site infection (HSSI), the microbiology implicated, associated outcomes including 30-day mortality and identify opportunities for prevention of infection. Methods: All patients undergoing coronary artery bypass grafting (CABG) procedures from January 2000 through September 2004 were included. Data were collected on preoperative, intraoperative, and postoperative factors, in addition to microbiology and outcomes. Results: Eighty-six of 3578 (2.4%) patients developed HSSI; 28 (32.6%) of them were classified as deep. The median time to detection was 17 (range, 4-51) days. An organism was identified in 64 (74.4%) cases; of them, a single pathogen was implicated in 50 (78%) cases. Staphylococcus aureus was the most frequently isolated pathogen: 19 (38% [methicillin-susceptible S aureus (MSSA) = 12, methicillin-resistant S aureus (MRSA) = 7]). Gram-negative organisms were recovered in 50% of cases, with Pseudomonas aeruginosa predominating in 11 (22%) because of a single pathogen. Multiple pathogens were identified in 14 (22%) cases. The 30-day mortality was not significantly different in patients with or without HSSI. Multivariate analysis showed age, diabetes mellitus, obesity, congestive heart failure, renal insufficiency, and duration of surgery to be associated with increased risk. Conclusion: Diabetes mellitus, obesity, congestive heart failure, renal insufficiency,,and duration of surgery were associated with increased risk for HSSI. S aureus was the most frequently isolated pathogen.