Fate of the right ventricle after fenestrated right ventricular exclusion for severe neonatal Ebstein anomaly

Objectives: Neonates with Ebstein anomaly can have severe left ventricular dysfunction caused by right ventricular enlargement and ventricular septal displacement. Fenestrated right ventricular exclusion and Blalock-Taussig shunt (Starnes procedure) have been performed to mitigate this problem; however, the fate of the excluded ventricle and its effect on the systemic ventricle have yet to be documented. Methods: Intermediate-term data have been retrospectively collected on the 12 survivors of neonatal right ventricular exclusion. Echocardiographic examinations were compared from the time of the original right ventricular exclusion and before second-stage Glenn palliation. Measurement of the Great Ormond Street ratio (area of right atrium plus atrialized right ventricle divided by area of trabeculated right ventricle plus left atrium and left ventricle), ratio of right ventricular to left ventricular area, degree of ventricular septal impingement into the left ventricle, and left ventricular shortening fraction have been documented. Results: In the 12 survivors of right ventricular exclusion, a decrease in the mean Great Ormond Street ratio was observed (before fenestrated right ventricular exclusion: 1.04 ± 0.49 vs before Glenn palliation: 0.31 ± 0.10, P = .01). The average pre-Glenn right ventricular/left ventricular ratio was substantially less than 1.0 (mean, 0.63 ± 0.27), demonstrating right ventricular regression. The degree of left ventricular septal impingement decreased by an average of 38% (P = .008), normalizing left ventricular morphology. At the time of Glenn palliation, the left ventricular shortening fraction was normal in all patients (mean, 42% ± 7%). Conclusions: After neonatal right ventricular exclusion (Starnes procedure) for severe Ebstein anomaly, there is a reduction in right ventricular size, as demonstrated by echocardiographic evidence of a significant decrease in Great Ormond Street ratios. This regression correlates with ventricular septal realignment and normalization of left ventricular function.