Mid-term outcomes in unbalanced complete atrioventricular septal defect: role of biventricular conversion from...

Management strategy for unbalanced complete atrioventricular septal defects (CASVSDs) includes single-ventricle (SV) palliation and primary or staged biventricular (BiV) repair. More recently, BiV conversion (BiVC) from SV palliation and staged BiV recruitment (BiVR) have also been advocated. This study assesses mid-term outcomes in patients with unbalanced CASVSDs according to management strategy.

Consecutive patients with unbalanced CASVSDs who underwent surgery at a tertiary care centre from January 2000 to February 2016 with institutional review board approval. The index surgery was defined as the first palliation procedure for the SV group, a BiV repair for the BiV repair group and conversion or the first procedure for recruitment for the BiVC/BiVR group. Kaplan-Meier and Cox regression were used for time-to-event analysis of death/transplant and unplanned reinterventions that occurred after the index surgery.

There were 212 patients: 82 (38.7%) had SV palliation, 67 (31.6%) had BiV repair and 63 (29.7%) had BiVC/BiVR, respectively; 50 patients had undergone a successful BiVC. There were 93 (43.9%) boys; 51 (24%) patients had Down syndrome; and 101 (48%) patients had heterotaxy. In the entire cohort, there were 40 (18.9%) deaths, 110 (51.9%) reinterventions, 82 (38.7%) surgical reinterventions and 70 (33%) catheter reinterventions, with some patients having more than 1 reintervention. Median length of follow-up was 35 (range 1-192) months. The BiVC/BiVR group had a transplant-free survival benefit similar to that of the primary BiV repair group compared with the SV group. The BiV repair group needed fewer catheter-based reinterventions compared with the SV and BiVC/BiVR groups.

BiVC or BiVR from an SV pathway can be achieved with low rates of mortality and morbidity in patients with unbalanced CASVSDs.