Neonatal Common Atrioventricular Valve Replacement After Failed Staged Biventricular Repair

Balanced complete atrioventricular septal defect (cAVSD) with aortic coarctation (CoA) is generally considered amenable to staged biventricular repair (BVR). However, anatomic suitability does not necessarily guarantee functional stability. We report a 3.5-kg neonate with balanced cAVSD (Rastelli type A), severe common atrioventricular valve regurgitation (CAVVR), and CoA. Preoperative echocardiography indicated suitability for BVR. At 9 days of age, arch repair and pulmonary artery banding (PAB) were performed. However, weaning the patient from cardiopulmonary bypass was impossible because of profound hypotension, and transesophageal echocardiography demonstrated worsening of CAVVR. PAB adjustment and removal were ineffective. Intraoperative inspection revealed a severely dysplastic valve morphology incompatible with durable repair. After myocardial recovery with extracorporeal membrane oxygenation support, the patient was converted to a univentricular pathway. The patient subsequently underwent common atrioventricular valve replacement, Damus-Kaye-Stansel anastomosis, and right ventricle-to-pulmonary artery shunt placement. Postoperative ventricular function was preserved without residual regurgitation. This case underscores the importance of flexible intraoperative decision-making guided by direct valve assessment and timely strategic conversion in high-risk neonates with cAVSD and severe CAVVR.