Role of the Right Ventricle Overhaul Procedure in Comprehensive Management for Pulmonary Atresia With Intact Ventricular Septum ― A Magnetic Resonance Imaging-Based Study ―

We evaluated the surgical outcomes of modified right ventricle (RV) overhaul (mRVOh), implemented as part of comprehensive management for pulmonary atresia with intact ventricular septum (PA-IVS). Twenty-five mRVOh procedures were performed in 23 patients with PA-IVS without RV-dependent coronary circulation. The procedure involved RV sinus myectomy, infundibular muscle resection, and tricuspid valve (TV) and pulmonary valve (PV) repair. In addition, in neonates and young infants, Blalock-Taussig shunt or patent ductus arteriosus banding was performed simultaneously. TV and PV annulus sizes were measured using echocardiography; RV function and volume were assessed using magnetic resonance imaging (MRI) in 18 patients. The median age and body weight at the time of mRVOh were 7.0 months and 7.1 kg, respectively. Biventricular repair was performed in 19 patients, and 6 required reoperations, including 2 with redo mRVOh. After mRVOh, the mean TV and PV annulus z-scores showed a significant increase towards the normal range, from -1.91 to -1.40 (P=0.031), and from -2.23 to -1.11 (P=0.014), respectively. Serial postoperative MRI showed significant increases in RV end-diastolic and end-systolic volume indices, stroke volume index, and cardiac index (P<0.001 for all), with preserved RV function. Both RV size and TV annulus showed proportionate growth after mRVOh. mRVOh may be a viable option for facilitating sustainable RV and TV growth in selected patients with PA-IVS.