Staged repair of borderline hypoplastic heart disease with early biventricular conversion

Objective: In select patients with borderline ventricular hypoplasia, we adopted a strategy of initial single ventricle palliation followed by staged or direct biventricular conversion by 2 years of age.Methods: Between 2018 and 2023, 14 newborns with borderline hypoplastic heart disease deemed high-risk for primary biventricular repair underwent palliative procedures as a neonate/infant, followed by staged or direct biventricular conversion.Results: Of the 14 patients, 6 had borderline left ventricles (LV) and 8 had borderline right ventricles (RV).Index neonatal operations were performed in 12 patients and included Norwood operation (n=5), pulmonary artery band (n=3), ductal stent (n=3), and hybrid Norwood (n=1).Five patients underwent direct biventricular conversion, and the remaining 9 patients underwent staged ventricular recruitment operations at a mean age of 6 months (range 3 -11 months).Ventricular recruitment operations included atrial septation with or without ventricular rehabilitation, atrioventricular valve repair, or outflow tract operations.At a mean duration of 8 months (range 4 -10 months) following ventricular recruitment, there was a significant increase in chamber volume, aortic valve, and mitral valve size in patients with borderline LVs, and a normalization of the RV:LV end diastolic volume ratio in patients with borderline RVs.To date, 13 of 14 patients have undergone successful biventricular conversion at a mean age of 16 months (range 4 -31 months). Conclusions:In select newborns with borderline hypoplastic heart disease, single ventricle palliation followed by staged or direct biventricular conversion may increase infant survival while allowing for early attainment of a biventricular circulation.