Reverse Double Switch Operation for the Borderline Left Ventricle

Objective (s): This study investigates outcomes of the reverse double switch operation (R-DSO) and ventricular switch (VS), novel approaches for patients with D-looped borderline left hearts that utilize the morphologic right ventricle as the systemic ventricle and the hypoplastic left ventricle as the sub-pulmonary ventricle. Methods This retrospective review analyzed early outcomes of children who underwent R-DSO/VS at a single institution between 2015 and 2023. Our primary endpoints were right ventricular (RV) function and tricuspid regurgitation (TR). Secondary outcomes included mortality, reoperation, and perioperative complications. Results Twenty-eight patients underwent either R-DSO (N=19) or VS (N=9). In nineteen patients, a decompressing bidirectional cavo-pulmonary shunt was utilized, creating a reverse 1.5 switch. Median age at R-DSO/VS was 3.1 years (range 9 months-12 years). At a median follow-up of 1.0 years (range 38 days-7.2 years), no mortalities or heart transplants had occurred. Mild-moderate or greater RV dysfunction was detected in four patients, and mild-moderate or worse TR was also detected in four patients. Three patients required reoperations. Preoperative RV EF < 55% was associated with higher incidence of postoperative RV dysfunction. Conclusions The R-DSO/VS strategy is an alternative to single ventricle palliation or anatomic biventricular repair in the borderline left heart. Concerns for RV dysfunction and TR mandate close monitoring. Patients with preoperative RV dysfunction may be at risk for postoperative RV dysfunction. Further studies with longer follow-up are needed to delineate outcomes in comparison to the Fontan pathway and identify optimal candidates for this novel strategy.