The heart after surgery for congenital heart disease.

The pathology of the heart following surgical correction for congenital cardiac defects has not been fully explored. This study is based on valvar aortic stenosis, atrioventricular septal defect, complete transposition of the great arteries, and Fallot's tetralogy. Emphasis has been put on preexistent gross pathology, with histological verification, and postoperative complications. Among patients with aortic valve stenosis preexistent anomalies dominated (left ventricular hypoplasia, mitral valve abnormalities, left ventricular endocardial fibroelastosis). The findings suggest that the cases represent an extreme within a spectrum and could explain the late postoperative dismal results in patients suffering from congenital left heart obstruction. In patients with atrioventricular septal defects the important pathology related predominantly to the operative procedure (injury to the atrioventricular bundle, patch dehiscence at the site of the atrioventricular node, inadequate repair of the left atrioventricular valve leaflets) and to pulmonary obstructive vascular disease. In complete transposition of the great arteries, with or without ventricular septal defects, technical problems dominated. Obstruction of the systemic and pulmonic venous pathways, atrial dysrhythmia, and tricuspid valve injury were the most serious complications following Mustard's procedure. The Rastelli-type procedure was complicated by degeneration and calcification of the porcine valve and crowding of the left ventricle. The arterial switch was complicated by abnormal origin and course of the left circumflex artery, which led to kinking and myocardial infarction. In Fallot's tetralogy surgical complications (injury to the atrioventricular bundle and the tricuspid valve) were the most important. The study discloses that the heart after surgery for congenital heart disease cannot be considered without taking preexistent pathology into account. Careful preoperative investigations are mandatory, since most anomalies could have been detected and, hence, might have changed the operative result.