Coronary to pulmonary artery collaterals in patients with pulmonary atresia and ventricular septal defect

Background. The frequency, distribution, and surgical importance of coronary artery to pulmonary artery (CAPA) collaterals have not been established. The aim of this study was to establish prevalence, anatomical pattern, and significance of CAPA in patients with pulmonary atresia and ventricular septal defect (PA/VSD). Methods. We reviewed cardiac catheterization and operative data of 87 consecutive, unselected patients who underwent one-stage complete unifocalization for PA/VSD and assessed major systemic to pulmonary collaterals from July 1992 to June 1998. Results. CAPA collaterals were diagnosed in 9 of 87 patients (10%). The collaterals originated from the left coronary artery system in 7 patients and the right in 2. Collaterals from the left coronary system arose from the left main coronary artery in 3 patients and the circumflex in 4. All collaterals joined the central pulmonary artery, which bifurcated and supplied both lungs. One collateral from the right coronary system joined the stump of the main pulmonary artery and the other gave origin to a true left pulmonary artery, which was the sole supply to 75% of the left lung. Coronary artery enlargement was seen in 2 patients only. No patient had evidence of myocardial ischemia. Coronary collaterals comprised a dual source of pulmonary blood flow in all but 1 patient. During unifocalization, the CAPA collaterals were ligated at its origin in all cases, and the collateral from the right coronary to the left pulmonary artery was unifocalized. Conclusions. The prevalence of CAPA collaterals in patients with PA/VSD is approximately 10%. The diagnosis may be missed without appropriate angiograms. We recommend selective ascending aortogram or selective coronary angiogram in all patients. (C) 2000 by The Society of Thoracic Surgeons.