Fetal aortic valvuloplasty

Fetal aortic valvuloplasty is considered for fetuses with severe valvar aortic stenosis and echocardiographic features suggesting a risk of progression to hypoplastic left heart syndrome. Though surgical options are available for infants with hypoplastic left heart syndrome, morbidity and mortality are high. So if progression to hypoplastic left heart syndrome can be prevented by fetal aortic valvuloplasty, that would be theoretically a great boon. But centers which offer fetal aortic valvuloplasty are very few and cases suitable for fetal aortic valvuloplasty are quite rare. Hence there is difficulty in attaining good case volumes for optimal procedural success. A retrospective single centre cohort analysis of attempted fetal aortic valvuloplasty from a pioneering centre, of cases from 2000 to 2020 has been published [1].

165 procedures were attempted in 163 patients with a median gestational age of 24.6 weeks. Overall technical success was 85% and as expected, it was better in the last decade. Higher left ventricular long axis dimension and ejection fraction were independently associated with odds of technical success. Younger gestational age and longer procedure times were associated with higher serious adverse events. Fetal demise occurred in about 8% of cases. Fetal cardiac intervention team included pediatric cardiology imaging specialist, fetal cardiology nurse practitioner, two interventional pediatric cardiologists, ultrasound radiologist, maternal-fetal medicine physician, fetal anaesthesiologist and maternal anaesthesiologist.

Currently all procedures are done percutaneously under ultrasound guidance following maternal spinal or epidural anaesthesia. Fetal positioning to get an anteriorly oriented left ventricular apex is performed with external maternal manipulation before giving paralytic and analgesia to the fetus. 19 gauge cannula of 13 cm length and over the wire coronary balloons are used for the procedure. Maternal skin to fetal left ventricular chamber distance must be less than the cannula’s working length of 10.8 cm. Hence procedure cannot be considered in case of maternal body mass index more than 40 kg/sq m. Procedure is done under high quality ultrasound imaging guidance.

Reference

1. Ryan Callahan, Kevin G. Friedman, Wayne Tworetzky, Jesse J. Esch, Lynn A. Sleeper, Minmin Lu, Arielle Mizrahi-Arnaud, Roland Brusseau, Terra Lafranchi, Louise E. Wilkins-Haug, Stephanie H. Guseh, Carol B. Benson, Mary C. Frates, Mirjam Keochakian, and Diego Porras. Technical Success and Serious Adverse Events for Fetal Aortic Valvuloplasty in a Large 20-Year Cohort. JACC Adv. 2024 Mar, 3 (3) 100835.