Risk Factors for Deep Sternal Wound Infection after Coronary Artery Bypass Grafting

(Department of Cardiovascular Surgery, Shizuoka City Hospital, Shizuoka, Japan)
Hidetoshi Masumoto Mitsuomi Shimamoto Fumio Yamazaki
Masanao Nakai Shoji Fujita Tatsuya Itonaga
Deep sternal wound infection (DSWI) following coronary artery bypass grafting (CABG) is associated with a high rate of mortality and is therefore considered a serious complication. In the present study, we investigated the risk factors for post-CABG DSWI. The subjects were 171 patients who underwent CABG via median sternotomy out of 173 consecutive patients who underwent isolated CABG at our department between January and December 2003. There were 3 (1.8%) in-hospital deaths. Univariate analysis was initially performed on each of the independent factors for DSWI, and multivariate analysis was then performed using binomial logistic regression analysis with the independent factors as covariables on the independent variables that reached statistical significance. DSWI was observed in 8 patients (4.7%), 1 (12.5%) of whom died in the hospital. Five (62.5%) of the 8 patients were given a diagnosis of mediastinitis. The results of univariate analysis revealed statistical significance (p＜0.05) for the following independent factors: diabetes (oral drug therapy), aortic clamping time (although only 97 patients who underwent aortic cross clamp were included in the analysis), homologous blood transfusion, reexploration for bleeding, long-term intubation or reintubation, maximum blood glucose level after surgery, and a positive blood culture. Multivariate analyses were performed on these factors (except for aortic clamping time) that were statistically significant in the univariate analysis using the factors as covariables. A positive blood culture (odds ratio 142.2; p＝0.001; 95% confidence interval, 7.2-2799.8) and reexploration for bleeding (odds ratio 36.7; p＝0.019; 95% confidence interval, 1.8-747.5) were found to be significant independent risk factors for post-CABG DSWI. We identified multiple risk factors related to DSWI.
　Jpn. J. Cardiovasc. Surg. 36: 175-179 (2007)