Delayed sternal closure in newborns after surgery for congenital heart defect

Abstract

Background: Primary sternal closure after surgery for congenital heart defect is not feasible in all newborns because of tissue swelling, cardiomegaly, or postoperative bleeding. Therefore, in selected patients, the method of delayed sternal closure has been used to prevent low cardiac output, primarily in the operating theatre. Delayed sternal closure has also been used in the early postoperative period in patients with low cardiac output or after successful cardiopulmonary resuscitation at the cardiac intensive care unit. Objective: Retrospective analysis of incidence, indication, used techniques, and complications of delayed sternal closure in newborns after open-heart surgery for congenital heart defect using cardiopulmonary bypass. Methods: Between January 1992 and June 2008,577 newborns were operated on at Kardiocentrum, Motol University Hospital, Prague. Of these, 572 surviving patients make up the study cohort. Delayed sternal closure was undertaken in 239 (41.8%) patients, weighing 1450-4650 g (median 3250 g) at the age of 0 to 28 days (median, 7 days). Five patients were excluded from the study because of intraoperative death. Results: The surgeon decided for delayed sternal closure in 223/239 patients in the operating theatre because of mediastinal tissue edema in 58 cases, postoperative nonsurgical bleeding in 53 cases, to avoid low cardiac output in 49 cases, in all (30) newborns with the hypoplastic left heart as part of the surgical protocol, because of marked cardiomegaly in 28 cases, and because of pulmonary edema or ventilatory problems in five cases. Emergency secondary delayed sternal closure was necessary in the early postoperative period at the intensive care unit in 16/239 patients because of cardiac tamponade in eight newborns, because of low cardiac output in six, and after successful cardiopulmonary resuscitation in two. Delayed sternal closure was used in all patients with the hypoplastic left heart. The most frequent congenital heart defect in which delayed sternal closure was employed was interruption of the aortic arch in 71.8% of cases, and double outlet right ventricle in 71.4% of operated newborns. In newborns with functional single ventricle physiology, it was used in 68.7% of cases, and in patients with persistent truncus arteriosus and interruption of the aortic arch in 66.6% of cases. In persistent truncus arteriosus and critical aortic stenosis, delayed sternal closure was indicated in half of the patients having surgery. Primary sternal closure prevails in any other congenital heart defect. Newborns with delayed sternal closure and total anomalous pulmonary venous connection and persistent truncus arteriosus were significantly younger at the time of surgery. Cardiopulmonary bypass was significantly longer in the group of patients with transposition of the great arteries and persistent truncus arteriosus, and aortic cross clamp was significantly longer in transposition of the great arteries and total anomalous pulmonary venous connection with delayed sternal closure. Definitive sternal closure was performed 4 hours to 52 days (median 48 hours) after the operation in 90.4% (216 of 239) of patients. Twenty-three patients died with the open chest. The most common complication of delayed sternal closure was secondary wound healing requiring resuture in 30 newborns (12.5%). The difference between primary sternal closure and delayed sternal closure is statistically significant (24 out of 333, 7.2%; p = 0.044). Mediastinitis occurred in four patients (1.7%). In-hospital mortality was 13.4%. There was no causal relationship between delayed sternal closure and patient mortality. Conclusions: Delayed sternal closure is a therapeutic life-saving procedure in newborns after congenital heart defect surgery, which may help avoid many critical postoperative situations. The incidence of mediastinitis was not significantly higher in patients with delayed sternal closure compared with primary sternal closure newborns despite the open chest, and the prolonged and complicated postoperative course. The need for resuture was higher in newborns with delayed sternal closure as compared with those having the chest closed primarily. However, the groups did not differ in the incidence of mediastinitis. The slightly higher incidence of problems related to wound healing is presumably well outweighed by the benefits of delayed sternal closure.