The sources of pulmonary blood flow in patients with pulmonary atresia and ventricular septal defect (PA/VSD) are very diverse, and detailed informations for the pulmonary circulation are essential for successful treatment. The purpose of this study is to examine and define the origins, distributions and characteristics of collateral circulations in patients with PA/VSD and major aortopulmonary collateral arteries (MAPCAs).

34 patients diagnosed as PA/VSD and MAPCA were studied between May 1992 and April 1996. 85 MAPCAs were investigated for the sites of origin, distributions and characteristics by review of biplane angiograms. The characteristics of MAPCAs were examined in the aspects of anastomosis sites and sites/types of stenosis.

1) In 34 subjects, a total of 85 MAPCAs existed which supplied blood to 344 bronchopulmonary segments (4.1 BPS/MAPCA). 2) The origin sites of MAPCAs were the descending aorta (72%), the branch of aortic arch (16%), and the aortic arch or ascending aorta (12%). 3) The BPSs which frequently take primary blood supply from MAPCA were the 3 BPSs of upper lobe and superior / posterior basal segment of lower lobe in the right lung, and the superior / posterior basal segment of lower lobe in the left lung. 4) The BPS having apparent dual blood supply was 13.4% and the most frequent was the superior and posterior basal segment of the right lower lobe. 5) In total, 64% of MAPCA had anastomosis, and anastomosis in the lobar pulmonary artery was 48% to be the most frequent. 6) Stenosis was observed in 61% of MAPCAs. The site of stenosis was midportion (33%), originating portion (27%), multiple (26%), peripheral (14%), and the type of stenosis was focal (53%), segmental (31%), diffuse (16%), in the order of frequency.

In PA/VSD and MAPCA, selective angiogram should be performed in all the different blood-supplying sources of the lung for detailed information of the pulmonary circulation. When the blood sources of the pulmonary circulation is uncertain, elaborated efforts to find the blood sources, by angiograms in the frequent locations of MAPCA, are neccessary. We believe this study to be useful for precise planning in the diagnosis and treatment of PA/VSD and MAPCA.