Association of atrial septal fenestration with outcomes after atrioventricular septal defect repair: a Congenital Heart Surgeons’ Society study.

Structured Abstract Objective During repair of atrioventricular septal defect (AVSD), surgeons may leave an atrial level shunt when concerned about postoperative physiology, or as part of routine practice. However, the association of fenestration with outcomes is unclear. We sought to determine factors associated with mortality after biventricular repair of AVSD. Methods We included 581 patients enrolled from 32 Congenital Heart Surgeons’ Society (CHSS) institutions from Jan. 1, 2012 – June 1, 2020 in the CHSS AVSD cohort. Parametric multiphase hazard analysis was used to identify factors associated with mortality. A random effect model was used to account for possible inter-site variability in mortality. Results An atrial fenestration was placed during repair in 133/581 (23%) patients. Overall five-year survival after repair was 91%. Patients who had fenestration had an 83% 5-year survival versus 93% for those not fenestrated (p Conclusions An atrial communication at biventricular repair of AVSD is associated with significantly reduced long-term survival after adjusting for other known associated factors, including unbalance. These findings may challenge the routine practice of fenestration.