The research of selective unifocalization in patients with pulmonary atresia with ventricular septal defect and major aortopulmonary collaterals and recognition of major aortopulmonary collaterals from the perspective of histopathology

Objective To investigate the clinical outcomes of selective major aortopulmonary collaterals(MAPCAs) unifocalization and report histopathological findings in patients with pulmonary atresia with ventricular septal defect and major aortopulmonary collaterals(PA/VSD/ MAPCAs). Methods The study enrolled 6 MAPCAs/VSD/PA patients with age ranged from 6 to 96 months and body weight ranged from 5.0 to 23.0 kg. These patients underwent selective MAPCAs unifocalization and primary repairs. Preoperative cardiac catheter, selective arteriography, cardiac CTA and intraoperative pathology were performed to identify different function, anatomic distribution and histopathology of MAPCAs. Results 6 MAPCAs/VSD/PA patients underwent selective MAPCAs unifocalization and primary repair. No death occurred after operation and at follow-up which lasted for 1 to 20 months. Preoperative cardiac catheter, selective arteriography and intraoperative histopathology demonstrated distribution of functional MAPCAs similar to native pulmonary artery arborization and participating in arterial gas exchange. Functional MAPCAs were classified into elastic arteries according to histopathology. Conclusion There are two histological type of MAPCAs which play different roles. Selective unifocalization to functional MAPCAs which are classified into elastic arteries like native pulmonary artery is a safe and effective treatment approach for PA/VSD/MAPCAs. Key words: Pulmonary atresia; Major aortopulmonary collaterals; Selective unifocalization; Histopathology; Elastic arteries