An Adult Case of Double Outlet Right Ventricle and Right Ventricular Outflow Tract Stenosis Caused by Subpulmonary Membrane

We report a rare case of surgery for double-outlet right ventricle (DORV) and right ventricular outflow tract (RVOT) stenosis in adulthood; we also present a review of the literature. A 65-year-old man who had been diagnosed with a ventricular septal defect when he was a child and had undergone catheter ablation for paroxysmal atrial fibrillation at 57 years of age presented to our hospital with exertional fatigue. Echocardiography revealed DORV, a ventricular septal defect (VSD), and RVOT stenosis caused by subpulmonary membrane. Cardiac catheterization revealed a pulmonary to systemic flow ratio (Qp/Qs) of 2.7, a mean pulmonary artery pressure of 42 mmHg, a pulmonary vascular resistance (Rp) of 5.25 unit・m2, and a pressure gradient between RVOT and the right ventricular inlet of 30 mmHg. Right ventricular pressure was 80% of left ventricular pressure, and pulmonary hypertension with increased pulmonary blood flow was observed. During surgery, the patient underwent VSD closure and baffling of the left ventricle to the aorta, resection of the subpulmonary membrane in the right ventricular outflow tract, and closure of the left atrial appendage. The postoperative course was uneventful. The patient was extubated on the first postoperative day, transferred to the general ward on the sixth day, and discharged on the seventeenth day. Postoperative echocardiography indicated that the RVOT stenosis had improved, and that right ventricular pressure had decreased to less than 50% of the left ventricular pressure.