Sternal defects associated with congenital pericardial and cardiac defects.

We describe three cases of sternal defects of varying severity associated with other congenital anomalies. In the most severe case, both anterior and posterior defects were seen, with near-absence of the sternum and pericardium continuous with a large omphalocele. This resulted in external location of organs usually confined within the thoracic and abdominal cavities. A ventricular septal defect was present, and the arterial duct was absent. The course of the ascending aorta was anomalous. The baby had anencephaly and rachischisis. In the intermediate case, a proximal sternal cleft was associated with shortening of the sternum, and absence of the manubrium. Anterior pericardial and diaphragmatic defects were seen, while a scalp defect and an encephalocele were present on the posterior aspect of the head. This baby had tricuspid atresia. The remaining case had only an anterior defect with a shortened sternum. A supra-umbilical omphalocele contained a left ventricular diverticulum without interposing pericardium or diaphragm. Ventricular and atrial septal defects were present. The first two cases can be considered as representing failure of development of both an anterior and a posterior midline field. The third case, much milder than the other two, represents failure of development of an anterior field.