Initial Experience in Chile with Stent Implantation in the Right Ventricle Outflow Tract in High-Risk Patients with Tetralogy of Fallot.

Abstract

Tetralogy of Fallot (ToF) treatment is difficult in patients with surgical risk factors or unfavorable anatomy. Stent implantation in the right ventricular outflow tract (RVOT) is an option for these patients. We report our initial experience in Chile withRVOT stenting in patients with ToF. Retrospective and descriptive study conducted in three pediatric cardiovascular centers in Chile between 2012 and 2015, including all ToF patients with stent in the RVOT as first procedure. Clinical records, echocardiographic, interventional, and surgical reports were reviewed for demographics and information of RVOT and pulmonary arteries. 12 newborns with ToF were included (75% female). Median age was 20days (1-70) and mean weight was 2178g (1400-3414). Saturations increased after the procedure from 74.3% (55-88) to 88.5% (80-98%), (p < 0.01). No complications or mortality were related to interventions. Follow-up was 11months (7-36). Median right and left pulmonary arteries Z-score increased from - 4.0 (- 5.2 to - 0.3) and - 1.5 (- 4.8 to - 0.26) to + 0.53 (0.0 to 2.2) and + 1.1 (0.5 to 2.9), (p < 0.05), respectively. Nakata index increased from 63mm2/mm2 (35 to 143) to 162mm2/mm2 (107 to 197), (p < 0.05). Surgical repair was performed at a median of 4months (2-7). Transannular patch repair was necessary in all patientsand there wasno surgical mortality. RVOT stenting is a safe and useful option for patients with ToF and surgical risk factors or unfavorable anatomy. It increases the pulmonary blood flow, improving saturation and pulmonary artery growth as a bridge for surgical repair.