Relationship of Aortopulmonary Collaterals and Pulmonary Artery Development During Staged Single Ventricle Reconstruction

To evaluate the relationship of aortopulmonary collaterals and the development of central pulmonary arteries during staged palliation. A total of 287 patients, who underwent staged palliation with bidirectional cavopulmonary shunt and total cavopulmonary connection between 2008 and 2019, had available angiography. Pulmonary artery index was calculated using pulmonary angiography as described by Nakata and colleagues. Aortopulmonary collaterals were observed in 47 (16%) patients at stage II palliation, in 131 (46%) at total cavopulmonary connection, and afterwards in 49 (7%). The interventional closure of aortopulmonary collaterals was performed before stage II in 12 (4%) patients, before Fontan completion in 38 (13%), and afterwards in 39 (14%). Presence of aortopulmonary collaterals before stage II was not associated with the pulmonary artery index (129 vs. 150 mm²/m², p = 0.176) at stage II. In contrast, aortopulmonary collaterals before the Fontan completion were associated with lower pulmonary artery index (154 vs. 172 mm²/m², p = 0.005), and right pulmonary artery index (99 vs. 106 mm²/m², p = 0.006). Patients who underwent interventional closure of aortopulmonary collaterals before total cavopulmonary connection had lower pulmonary artery index (141 vs. 169 mm²/m², p < 0.001), lower right pulmonary artery index (93 vs. 106 mm²/m², p = 0.007), and left pulmonary artery index (54 vs. 60 mm²/m², p = 0.013) at Fontan completion. The presence of aortopulmonary collaterals did not influence pulmonary artery size by the time of stage II. However, presence of aortopulmonary collaterals was associated with under-developed pulmonary arteries at Fontan completion, especially in patients who needed interventional closure of aortopulmonary collaterals.