The impact of vacuum-assisted closure on long-term survival after post-sternotomy mediastinitis

Background. Post-sternotomy mediastinitis after coronary artery bypass grafting is reported to be a strong predictor for poor late survival when using conventional wound-healing therapies. The aim of this study was to compare the long-term survival after vacuum-assisted closure treated mediastinitis following coronary artery bypass grafting with that of patients without mediastinitis. Another objective was to identify risk factors for developing mediastinitis. Methods. Forty-six patients were treated for mediastinitis, with vacuum-assisted closure but without additional tissue flaps, after isolated coronary bypass grafting between January 1999 and September 2004. During this period, 4,781 patients underwent isolated coronary bypass grafting without mediastinitis. Actuarial survival was compared with the log-rank test. Univariate and multivariate analysis were used to identify risk factors for mediastinitis. Results. There was no difference in early or late survival between the mediastinitis group treated with vacuum-assisted closure and the control group (p = not significant). The survival at 1, 3, and 5 years was 92.9% +/- 4.0%, 89.2% +/- 5.2%, and 89.2% +/- 5.2%, respectively, in the vacuum-assisted closure group; and 96.5% +/- 0.3%, 92.1% +/- 0.5%, and 86.9% +/- 0.8%, respectively, in the control group. Diabetes mellitus, low left ventricular ejection fraction, obesity, renal failure, and three-vessel disease were identified as risk factors for developing mediastinitis. Conclusions. This study suggests that patients with vacuum-assisted closure treated mediastinitis may have similar long-term survival as patients without mediastinitis after coronary artery bypass grafting. The independent risk factors identified were similar to those found in previous studies. Our data support that vacuum-assisted closure therapy minimizes the negative effects of mediastinitis on late survival after coronary artery bypass grafting.