Modified-Single Patch vs. Double Patch Repair of Complete Atrioventricular Septal Defects.

Biventricular repair of complete atrioventricular septal defect (CAVSD) is largely achieved using the double-patch (DP) or modified single-patch (MSP) techniques in the current era, however long-term results following MSP repair are not well defined. We aimed to compare long-term outcomes including reoperation and mortality after CAVSD repair using DP and MSP techniques, and identify risk factors associated with adverse outcomes. A retrospective cohort study was performed including all patients who underwent CAVSD repair using DP and MSP techniques at our institution between 17th May 1990 to 14th December 2015. Demographic details, early (≤30 days) and late (>30 days) outcomes (reoperation, mortality) were studied. Competing risks analysis with cumulative incidence function was used for survival analyses. Overall 273 consecutive patients underwent CAVSD repair (120 DP and 153 MSP) and 41 patients required reoperation during follow-up. Competing risks analysis showed no association between repair technique and reoperation (p=1.0) or mortality (p=0.9). Considering competing risks due to mortality, the cumulative incidence of reoperation at 5, 10 and 15 years was 14%, 17% and 17% for DP and 12%, 13% and 16% for MSP, respectively. Non-Down syndrome and moderate or greater left atrioventricular valve regurgitation were predictors for reoperation. Pulmonary artery banding was predictive of mortality, though strongly associated with earlier surgical era. Median follow-up duration was 8.0 years (IQR 3.9-20.8) for DP and 11.6 years (IQR 5.4-16.1) for MSP (p=0.4). Event-free survival is similar after DP and MSP repair of CAVSD indicating either repair technique can be safely utilised.