Modified single-patch repair for atrioventricular septal defects results in good functional outcomes in the absence of deep ventricular septal defects

Objectives: We compared 2-patch repair (TP) with modified single-patch repair (MSP) for complete atrioventricular septal defects and evaluated their effect on the left atrioventricular valve (LAVV) competence. We also identified risk factors for unfavorable functional outcomes. Methods: This retrospective study included 118 patients with complete atrioventricular septal defects who underwent intracardiac repair from 1998 to 2020 (MSP: 69; TP: 49). The median follow-up period was 10.4 years. The functional outcome of freedom from moderate or greater LAVV regurgitation (LAVVR) was estimated using the Kaplan-Meier method. Results: The hospital mortality was 1.7%(2/118) and late mortality was 0.8%(1/118). Eight patients required LAVV-related reoperation (MSP: 4; TP: 4) and none required left ventricular outflow tract-related reoperation. In the MSP group without LAVV anomaly, the receiver operating characteristic curve analysis revealed that the ventricular septal defect (VSD) depth was strongly associated with moderate or greater postoperative LAVVR, with the best cutoff at 10.9 mm. When stratified according to the combination of intracardiac repair type and VSD depth, the MSP-deep VSD (VSD depth>11 mm) group showed the worst LAVV competence among the 4 groups (P =.002). According to multivariate analysis, weight<4.0 kg, LAVV anomaly, and moderate or greater preoperative LAVVR were independent risk factors for moderate or greater postoperative LAVVR, whereas MSP was not a risk factor. Conclusions: Postoperative LAVVR remains an obstacle to improved functional outcomes. MSP provides LAVV competence similar to TP unless deep VSD is present. The surgical approach should be selected on the basis of anatomical variations, specifically VSD depth.