Prenatal interventional therapy in two cases with critical pulmonary stenosis or pulmonary atresia with intact ventricular septum

Abstract

Objectives: Two cases who underwent fetal pulmonary valvuloplasty (FPV) for pulmonary atresia with intact ventricular septum (PA-IVS) or critical pulmonary stenosis with intact ventricular septum (CPS-IVS) successfully were reported. The aim of the report was to explore the criteria for case selection, the technical essentials of FPV, and the postpartum outcome of the fetus. Methods: One case with PA-IVS and the other with CPS-IVS were enrolled in September 2016 and February 2017 in Guangdong General Hospital, and both cases were diagnosed with severe right ventricular dysplasia and tricuspid regurgitation by fetal echocardiogram. Parameters of right ventricle development and hemodynamics from echocardiography included tricuspid/mitral annulus (TV/MV), right ventricle/left ventricle long-axis (RV/LV), pulmonary/aortic annulus (PV/AV), tricuspid inflow duration/cardiac cycle, degree of tricuspid regurgitation (TR), blood flow direction of arterial duct and ductus venosus. Multidisciplinary team including the maternal-fetal cardiology, pediatric cardiology, cardiac surgery, obstetrics, neonatology and anesthesiology was summoned to discuss the indications and timing of PFV. Two cases underwent ultrasound-guiding trans-abdominal PFV at the 28 weeks of gestational age. Echocardiography was performed to observe the opening and closing of the pulmonary valve, and to evaluate the development of right ventricle and improvement in hemodynamics every 2-4 weeks until delivery. Results: From the technical perspective, pulmonary balloon valvuloplasty was successfully performed in these two cases. The opening of pulmonary valve improved in these two cases at 2-4 weeks after FPV. However, an obvious restenosis was detected in the first case at 5-8 weeks after FPV. In the first case, the echocardiography parameters including TV/MV, RV/LV, PV/AV and tricuspid inflow duration/cardiac cycle increased from 0.56, 0.42, 0.85,0.26 to 0.59, 0.51, 0.87, 0.32 at 5-8 weeks after FPV, respectively. However, the direction of blood flow through the arterial duct was still reverse. In the second case, TV/MV, RV/LV, PV/AV and tricuspid inflow duration/cardiac cycle ratio increased from 0.70, 0.63, 0.91,0.35 to 0.80, 0.80, 0.97, 0.42 at 5-8 weeks after FPV, respectively. The direction of blood flow through the arterial duct changed to bidirectional. Both fetuses were born alive. The first case underwent pulmonary valve commissurotomy and modified Blalock-Taussig shunt on the 8(th) day after delivery and received follow-up for 6 months. The strategy for the next-step therapy was still pending. The second case underwent transcutaneous pulmonary balloon valvuloplasty on the 19(th) day after delivery and received follow-up for 3 months. The opening of pulmonary valve improved obviously and the cardiac function was normal in the second case. Conclusions: FPV is safe and effective for fetus during the second and third trimester of pregnancy, and FPV is beneficial for the development of fetal ventricle, valve and large artery. In addition, FPV may help to avoid the postnatal surgery for isolated single ventricle, improve fetal heart failure and prevent fetal death.