Outcome of biventricular repair of congenital cardiac malformations with a borderline left ventricle

INTRODUCTION: Biventricular repairs are occasionally done on hearts with a borderline-sized left ventricle to avoid univentricular palliation. We aim to assess the outcome. MATERIALS AND METHODS: Data of 27 patients with borderline left ventricle that had undergone biventricular repair in our centers in the past 20 years (median follow-up: 5 years) were analyzed retrospectively. RESULTS: Successful primary repair was performed in 17 (63%) patients. Four (15%) patients initially underwent primary repairs, which were converted to Norwood reconstructions, hoping to re-attempt biventricular repair later. Primary Norwood reconstruction with a restrictive atrial septal defect or its hybrid equivalent were performed in 6 patients (2 Norwoods [7%], 4 Hybrids [15%]) for ventricular rehabilitation, with subsequent biventricular repair a few months later. The total number of procedures was 87 (average: 3.2 per patient). These figures do not include procedures for implantation of ECMO, re-operations for bleeding and delayed sternal closures because we consider these as parts of the procedures that immediately preceded them. This strategy failed in 8 (30%) patients: 7 died (4 within 1 year, 1 at 18 months, 1 at 3 years, 1 at 3.5 years), and 1 was converted to univentricular palliation eventually reaching Fontan completion. Four (15%) patients reached favorable outcomes: alive and asymptomatic with biventricular circulation, good ventricular function and normal-sized valves. The remaining 15 (55%) patients are alive but with residual lesions, which may include ventricular diastolic dysfunction, somewhat small mitral and/or aortic valves and pulmonary hypertension; 9 are in NYHA class I and 6 in class II. CONCLUSION: The results are suboptimal. Further studies are needed to identify ways of predicting who would benefit most from aggressively pursuing a biventricular strategy and offer it to them selectively.