Staged Approach: The Role of Delayed Repair Following Complete Unifocalization of Major Aortopulmonary Collateral Arteries with Ventricular Septal Defect and Pulmonary Atresia.

The presentation of pulmonary vasculature in pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (PA/VSD/MAPCA) is highly variable-as is the number, size and position of the MAPCAs and their relationship with the native pulmonary artery system. The priority in the management of this disease should be attaining timely and complete unifocalization, as opposed to single-stage full repair in every case. The merit of early unifocalization is that it secures the pulmonary vascular bed by (a) avoiding loss of lung segments from progressive stenosis/atresia of MAPCA origins, (b) preventing lung injury from high pressure/flow in areas fed by large, unobstructed MAPCAs, and (c) restoring central continuity of the pulmonary vasculature. Furthermore, there are a small but important group of patients with poorly developed vessels (about 10%-15% of the population) and/or diminutive native pulmonary artery vasculature that require initial shunt procedures to promote rehabilitation and growth of vessels before unifocalization can be attempted. During unifocalization, patients not suitable for single stage repair can be identified by intraoperative flow studies and can be successfully managed with staged strategies that provide time for growth and reinterventions on the pulmonary vasculature. Over 85% of patients can achieve unifocalization. Deferring closure of the VSD to a subsequent procedure is safe and these cases have similar survival to primary repair. Some patients (15%-20%) may never achieve VSD closure with this strategy but can still maintain a good quality of life with a restrictive right ventricular to pulmonary artery conduit and open VSD.