Surgical management of infected median sternotomy: closed irrigation vs. muscle flaps

Mediastinitis remains a serious complication of median sternotomy which requires prompt and aggressive surgical management. Debridement and closed irrigation has been the conventional mode of treatment. Failure to respond results in open drainage and delayed healing with its associated increased morbidity and mortality. Secondary closure with rectus muscle flaps has been a marked advance in the treatment of these patients. In an attempt to define guidelines for the treatment of mediastinitis complicating median sternotomy, a retrospective review of 2,400 cardiac surgical cases at St. Vincent's Hospital from 1977 through 1982 was performed. There were 25 cases (1%) of mediastinitis. Debridement and closed irrigation was successful in 16 patients (64%) with an average postoperative hospital stay of 19 days. Failure resulted in open drainage in 2 patients (8%) with an average hospital stay of 66 days and debridement and secondary closure by rectus muscle flaps in 7 patients (28%) with an average hospital stay of 28 days. There were no deaths in the entire series. Failure to respond to closed irrigation was not due to delay in diagnosis. The length of time between operation and the first sign of sternal dehiscence did not vary significantly. Sternal dissolution, the presence of anaerobic organisms, large volumes of purulent and necrotic material, however, were responsible for continued mediastinitis and further sternal dehiscence. Open irrigation and delayed closure with muscle flaps should be reserved for these patients and appears to decrease significantly morbidity and length of hospital stay. Surgical debridement and closed irrigation, however, remains the primary method of treatment of the less virulent forms of mediastinitis following median sternotomy.