Risk Factor, Mortality and Infection Rate of Mediastinum After Delayed Sternal Closure in Congenital Heart Surgery Patients

Background: Congenital heart surgery may lead to myocardial swelling and hemodynamic instability. Delayed sternal closure may be beneficial in this setting. The purpose of this study was to assess mortality and mediastinal infection rate associated with delayed sternal closure after congenital heart surgery and to evaluate the risk factors which affect mortality and mediastinal infection rate. Material and Method: We retrospectively reviewed 40 patients who underwent delayed sternal closure after repair of congenital heart disease at Yonsei Cardiovascular Hospital, from January 1994 to May 2001. In these patients, we assessed the mortality and mediastinal infection rate, and evaluated their risk factors including operation time, bypass time, aortic cross clamp time, duration to sternal closure and postoperative artificial ventilation time. Mediastinal infection was defined to have positive culture in mediastinum. Result: Hemodynamic instability was the most common indication for delayed sternal closure(n=36) and other indications included postoperative bleeding(n=2) and conduit compression(n=2). The median age at operation was 14.4±33.4 months old(range, 2days- 12years). The patients with postoperative bleeding and conduit compression were much older than the others. The sternum was left open for 4.5±3.4 days(range, 1-20days). Overall mortality was 25%(10/40) and mediastinal infection occured in 24.3%(9/37) (3 patients were excluded in mediastinal infection for early death). In risk factor analyses, only aortic cross clamp time had statistical significance for mortality in univariate analyses. However, multivariate analyses revealed that there were no significant predictors for risk of mortality and mediastinal infection. Conclusion: Delayed sternal closure after repair of congenital cardiac disease had relatively high mortality and mediastinal infection rate. But, in patients with hemodynamic instability, postoperative bleeding and conduit compression after repair of congenital cardiac disease, delayed sternal closure may be an effective life saving method.ope