Impact of Anatomical Sub-types and Shunt Types on Aortopulmonary Collaterals in Hypoplastic Left Heart Syndrome

This study aims to clarify the relation of development of aortopulmonary collateral arteries (APCs) with anatomical sub-types and the shunt types at Norwood procedure in patients with hypoplastic left heart syndrome (HLHS). A total of 140 patients with HLHS who completed 3 staged palliation between 2003 and 2019 were included. Incidence of APCs and corresponding interventions were examined using angiogram by cardiac catheterization, with respect to the anatomical sub-types and shunt types. Totally, APCs were observed in 87 (62%) of the patients; pre-stage II in 32 (23%), pre-stage III in 64 (46%), and after stage III in 40 (29%). The incidence of APCs before stage II was significantly higher in patients with aortic atresia/mitral atresia (AA/MA) compared with other sub-types (P = 0.022). Patients with right ventricle to pulmonary artery conduit (RVPAC) had a higher incidence of APCs originating from the descending aorta, compared with those with modified Blalock-Taussig shunt (20% vs 2%, P= 0.002). Interventions for APCs were performed in 58 (41%) patients; before stage II in 10 (7%), after stage II in 7 (5%), before stage III in 22 (16%), and after stage III in 32 (23%). Patients with AA/MA had more interventions before stage II (P= 0.019), and patients with aortic stenosis/mitral stenosis (AS/MS) had a lower incidence of interventions after stage III (P= 0.047). More than half of the patients with HLHS developed APCs. Before stage II, patients with AA/MA sub-type had a higher incidence of APCs, and those with RVPAC had significantly more APCs from the descending aorta.