Delayed sternal closure after cardiac operations in a pediatric population

The purpose of this study was to assess morbidity and mortality associated with delayed sternal closure after pediatric cardiac operations.

Hospital records were reviewed of all patients with an open sternum after a cardiac operation at Children's Hospital, Boston, from January 1992 to December 1995.

A total of 178 patients had delayed sternal closure with an overall mortality rate of 19%. The most common diagnosis of patients with delayed sternal closure was hypoplastic left heart syndrome (29%). Although myocardial distention or chest wall edema (n = 47) was a common indication to delay sternal closure, in many patients (n = 47) the sternum was left open electively to avoid postoperative cardiac or respiratory compromise. Successful sternal closure was achieved in 158 patients (89%) at a mean of 3.4 +/- 1.8 days after opening. There were significant increases in left atrial pressure (7.7 +/- 3.4 to 9.8 +/- 4.1 mm Hg, p = 0.00001) and right atrial pressure (8 +/- 3.2 to 10.1 +/- 3.3 mm Hg, p = 0.00001) with sternal closure. There was a small but statistically significant drop in pH (7.44 +/- 0.05 to 7.41 +/- 0.08, p < 0.0001) during sternal closure. The peak inspiratory pressure, delivered breaths per minute, and fraction of inspired oxygen all significantly increased during sternal closure. Clinical evidence of surgical site infection occurred in 12 (6.7%) of the patients with delayed sternal closure; mediastinitis developed in 7 (3.9%) patients.

Although delayed sternal closure after complex operations for congenital heart disease is often necessary in the operating room because of edema, unstable hemodynamic conditions, or bleeding, it can also be used electively to aid in hemodynamic and respiratory stability in the initial postoperative period. Our review supports a low morbidity associated with delayed sternal closure in a pediatric population.