Surgical Outcomes of Right Ventricular Outflow Tract Reconstruction With Biological Valved Conduits in Children: A Retrospective Single-Center Series From Vietnam

Background:Right ventricle-to-pulmonary artery (RV-PA) valved conduits are widely used for right ventricular outflow tract (RVOT) reconstruction in complex congenital heart disease. However, in developing countries, this technique is still limited to a few major centers, and evidence on long-term outcomes remains scarce. This study aimed to report early- and mid-term outcomes of RVOT reconstruction using biological valved conduits in pediatric patients at a Vietnamese tertiary center.Methods:We retrospectively reviewed all pediatric patients with complex congenital heart disease who underwent RVOT reconstruction with a biological valved conduit at our institution between March 2017 and August 2022. Patients were described overall and by clinical strata (first conduit for RVOT obstruction vs second conduit and pulmonary valve stenosis (PVS)). Outcomes included perioperative characteristics, in-hospital complications, mortality, echocardiographic assessment of conduit performance, and conduit-related reintervention or replacement.Results:A total of 34 children underwent RVOT reconstruction with 38 conduit procedures. The median age was 4.0 years (interquartile range 1.0–10.3), and 55.9% were male. Preoperative malnutrition was present in 38.2%, and prior cardiac surgeryor intervention in 67.6%. The RVOT obstruction subgroup had marked baseline hypoxemia, with a mean peripheral capillary oxygen saturation of 73.8%. Postoperative complications were frequent, particularly pneumonia (42.1%) and low cardiac output syndrome/heart failure (28.9%). Early mortality occurred in two patients (5.9%), and late mortality in one patient (2.9%). No conduit-related interventions were required during the index hospitalization. At discharge, the median systolic conduit gradient was 20 mmHg and increased during follow-up (mean 30.3 mmHg). At follow-up, mild and moderate stenosis were observed in seven (18.4%) and two (5.3%) cases, respectively. During follow-up, four patients underwent surgical conduit replacement at a median of 60 months, with severe valve calcification documented intraoperatively.Conclusions:In this single-center Vietnamese series, biological valved conduits enabled RVOT reconstruction with acceptable early outcomes despite substantial preoperative risk burden and frequent postoperative respiratory and cardiac morbidity. Mid-term follow-up demonstrated progressive conduit obstruction in a subset of patients and clinically relevant conduit replacement at approximately 5 years, consistent with structural valve degeneration.