Patients with both interrupted aortic arch (IAA) and truncus arteriosus (TA) have worse outcomes than those with either lesion in isolation. We determined outcomes and associated factors in this rare group.MethodsFrom 1987 to 1997, 50 (11%) of 472 neonates with IAA were identified with TA. Site of aortic arch interruption was distal to the left subclavian artery in 16% and between the left common carotid and subclavian artery in 84%. From the common arterial trunk, the pulmonary arteries arose from a main pulmonary trunk in 46%, common orifice in 22%, and separate orifices in 32%. At presentation, truncal valve stenosis was present in 12% and regurgitation in 22%.ResultsThere were 34 deaths, with a single early hazard phase. Overall survival from admission was 44%, 39%, and 31% at 6 months, 1 year, and 10 years, respectively. One patient had primary cardiac transplantation and 4 died without any intervention. The IAA repair alone was performed in 7 patients, with single stage repair of both IAA and TA in 38 patients. Associated factors for overall time-related death include female gender (p <0.001), type III TA (p <0.001) and one institution (low-risk; p <0.001). Results improved somewhat over time (p <0.001). At 5 years after IAA repair only 28% were alive without arch repair intervention, and at 5 years after TA repair only 18% were alive without conduit reoperation.ConclusionsThe combination of IAA and TA carries high early mortality, with high risk of reinterventions in survivors. One stage repair of both TA and IAA is the optimal management.