Aortopulmonary Septal Defect: Hemodynamics, Angiography, and Operation

Twenty-five patients with malseptation of the aortopulmonary trunk resulting in aortopulmonary septal defect (window) were evaluated in a unique combined surgical series assembled from two institutions participating in the USA-USSR Health Exchange Program. Typical aortopulmonary septal defect or window (type I) with the connection between the ascending aorta and main pulmonary artery was found in 21 patients. Four had a more cephalad defect (type II) between the ascending aorta and the origin of the right pulmonary artery. Hemodynamics were the consequence of a large left-to-right shunt (mean ratio of pulmonary to systemic flow, 3.0) with right ventricular hypertension (mean right ventricular pressure, 86 mm Hg) and increased pulmonary vascular resistance (mean, 7.4 U) (mean ratio of pulmonary to systemic vascular resistance, 0.33). Angiography may provide patterns that allow preoperative distinction between the two types of aortopulmonary septal defect and provide information important in planning the details of corrective operation. Operative techniques included ligation, direct suture, and patch closure of the aortopulmonary septal defect. The best method appeared to be patch closure by the transaortic approach; real and potential problems were associated with other techniques.