Right Ventricular Outflow Tract Reconstruction With a Polytetrafluoroethylene Monocusp Valve: A 20-Year Experience

Abstract

In patients with tetralogy of Fallot (TOF), pulmonary atresia (PA), and other congenital right ventricular outflow tract (RVOT) malformations, polytetrafluoroethylene (PTFE) monocusp outflow tract patches (MOTP) relieve obstruction and provide pulmonary valve competence. The purpose of this study was to determine whether our PTFE-MOTP was an acceptable short- and mid-term remedy for patients with TOF or PA as assessed by freedom from severe pulmonary regurgitation and freedom from reoperation. From 1994-2014, 171 patients (mean age 1.5 ± 1.5 years; median 1.1 years) with TOF or PA underwent initial right ventricular outflow tract (RVOT) reconstruction with a PTFE-MOTP. Patients were studied intraoperatively and serially postoperatively using echocardiography and cardiac magnetic resonance imaging (CMR) to determine pulmonary valve dysfunction defined as a peak gradient >40mmHg or valve regurgitation>moderate. The mean follow-up duration was 10.9 ± 5.8 years (range: 1 month-20 years). There were 5 late deaths and 1 early death. There was a significant difference between the preoperative and postoperative peak RVOT gradients (74.0 vs 25.2mmHg). Of the 171 patients, 25 were lost to follow-up, and 42 have required replacement of their monocusp valves 10.1 ± 5.0 years (range: 5 months-19 years) after original monocusp insertion. At 10-year follow-up, severe pulmonary regurgitation was seen in less than 25% of patients, and severe pulmonary stenosis was seen in less than 10% of patients. Since 2007, CMR was used in 44 patients to characterize cardiac function in patients under consideration for PTFE-MOTP replacement. The average right ventricular-to-left ventricular (RV/LV) ratio on CMR was 1.7 ± 0.5 in these patients. CMR also showed that RV ejection fraction (52 ± 9%) and left ventricular ejection fraction (58 ± 7%) were both preserved in most patients. The PTFE-MOTP is an excellent short-term and mid-term option for initial RVOT reconstruction, particularly in children with TOF with nonsalvageable pulmonary valve or PA-ventricular septal defect.