Repair of complete atrioventricular septal defect between 2 and 3.5 kilograms: Defining the limits of safe repair

Objectives: Repair of complete atrioventricular septal defect (cAVSD) is routinely performed at around 3 months of age with good results. However, some patients require earlier surgery due to heart failure or failure to thrive. It is uncertain whether cAVSD repair performed on patients ≤3.5 kg leads to increased mortality and reoperation on the left atrioventricular valve.

Methods: All patients who underwent cAVSD repair from 1990 to 2019 at a single institution were included in the study. Data were obtained from retrospective review of medical records and correspondence with cardiologists.

Results: Of 456 patients, 12.9% (59/456) weighed ≤3.5 kg at time of repair. This group was younger (P < .01) and had greater rates of heart failure (P < .01) and failure to thrive (P = .02). There was no significant difference in early mortality between the 2 groups (1.7% [1/59] vs 3.0% [12/397], P = 1.0). Survival at 20 years was 83.8% in those ≤3.5 kg, compared with 90.4% in those >3.5 kg, with no significant difference between the 2 groups (P = .68). Freedom from left atrioventricular valve reoperation at 20 years was 73.6% in those ≤3.5 kg, compared with 74.5% in those >3.5 kg, with no significant difference between the 2 groups (P = .45).

Conclusions: Repair of cAVSD in children ≤3.5 kg appears to be safe, with similar overall survival and freedom from reoperation compared with those >3.5 kg. These findings add further support to an approach of early complete repair in children with severe heart failure or failure to thrive.