Deep Sternal Wound Infections after Coronary Artery Bypass Grafting: Analysis of 29 Cases from Iraq

Abstract

Background: Deep sternal wound infection (DSWI), or mediastinitis, is a devastating complication of coronary artery bypass grafting (CABG). This prospective study aimed to assess our management of DSWI in view of the published literature. Methods: Over 2-years (ending in January 2016), 29 patients (20 males) developed DSWI amongst 520 patients who underwent standard CABG surgeries (5.6%). Pre-, intra- and postoperative variables were documented. Whenever possible, the infections were culture-verified. Besides antibiotics, patients received one or more of the following therapies: drainage, debridement, closed irrigation, sternal re-wiring, vacuum-assisted closure (VAC), and bone resection. Results: the male to female ratio was 2.2:1. Mean age was 58.1 ± 7.3 years. The mean body mass index (BMI) was 27.9 ± 3.4 kg/m2. There were 18, 16 and 11 patients with diabetes mellitus (DM), hypertension and chronic obstructive pulmonary disease (COPD) respectively. Cardiopulmonary bypass (CPB) was utilized in 26 (89.7%) patients with a mean time of 117.5 ± 23.3 minutes. Most surgeries (n = 21, 72.4%) lasted 5 - 6 hrs. According to Pairolero classification, there were 3 (10.3%) Type I, 22 (75.9%) Type II and 4 (13.8%) Type III infections. Four (13.8%) cases were culture-verified. Twenty-three (79.3%) DSWIs were surgically managed. Sternal re-wiring was performed in 14 (48.3%) cases while VAC was added to other therapies in 2 (6.9%) patients. DSWIs completely resolved in 18 (62.0%) patients within 3 - 24 weeks while two (6.9%) patients died within 30 days. Conclusion: We have identified six independent risk factors for DSWI (male gender, obesity, DM, hypertension, COPD and CPB), five of them are modifiable.