OBJECTIVES: This retrospective study aimed to investigate the feasibility of surgical closure of ventricular septal defect in children with trisomy 18 by assessing perioperative events and long-term survival. METHODS: From April 2008 to March 2024, 41 consecutive patients were referred to us for ventricular septal defect surgery. The defect was closed in 35 patients at the end (median age, 16 months
median body weight, 5.7 kg), 31 out of 37 patients after the preceding pulmonary artery banding according to our staged surgery policy and 4 patients without the banding. Sixty-five significant non-cardiac lesions existed concurrently, and 14 patients underwent tracheostomy before closure. The investigation was conducted by checking medical records and contacting the primary physician. RESULTS: Four patients died during the inter-stage after banding to closure (10.8%). Two of them were awaiting closure. Concomitant surgeries, 15 right ventricular muscle resections, or 1 arch repair, were performed along with closure. Arrhythmia was the most common adverse event (51.4%). Three patients required extracorporeal membrane oxygenation support. Transient but severe hepatic injury occurred in 11 patients (31.4%). There were two hospital death (5.7%) due to severe respiratory insufficiency or fulminant sepsis. Five patients died after discharge, three pneumonia and two sudden death, resulting in a 5-year estimated survival of 79.5%. Three hepatoblastoma and one hepatoangioma developed, but complete remission was achieved in all patients. CONCLUSIONS: Although further studies are mandatory, surgical closure of ventricular septal defect may be an effective treatment option even for children with trisomy 18.