Fetal aortic valvuloplasty (FAV) represents a significant advancement in the prenatal management of severe aortic stenosis (AS) and the prevention of hypoplastic left heart syndrome (HLHS). HLHS is a complex congenital heart defect characterized by the underdevelopment of left heart structures, rendering the left heart unable to support systemic circulation (Nasr and DiNardo, 2019). This intervention aims to modify the disease progression in utero, potentially averting the need for more complex surgical interventions postnatally.
The technique of FAV involves the percutaneous introduction of a balloon catheter into the fetal heart to dilate the stenotic aortic valve. This procedure is performed under ultrasound guidance, with maternal conscious sedation and fetal anesthesia to ensure precision and minimize risks. A technically successful FAV is defined by the balloon crossing the aortic valve, followed by inflation to increase valve orifice size, which is confirmed by increased flow across the valve or new aortic regurgitation (Marshall et al., 2005).
The primary objective of FAV is to promote left heart growth, thereby preventing the progression of AS to HLHS. Studies have demonstrated that FAV can achieve biventricular circulation in approximately 50% of cases where the procedure is technically successful (Pickard et al., 2020). However, this intervention is not without risks. The most significant risk is fetal demise, which occurs in about 8% of cases (Pickard et al., 2020). Additionally, there is the possibility of technical failure, which can result in continued progression to HLHS despite the procedure.
One of the main advantages of FAV is its potential to improve postnatal outcomes. By preventing the progression to HLHS, infants may avoid the need for the multi-stage surgical palliation required for single-ventricle physiology, which is associated with significant morbidity and mortality (Nasr and DiNardo, 2019). Successful FAV has been associated with higher rates of biventricular repair postnatally, which offers a better quality of life and long-term prognosis compared to single-ventricle palliation (Tworetzky et al., 2004).
FAV remains a highly specialized procedure with inherent risks. The procedure is technically challenging and requires a highly skilled multidisciplinary team, including maternal-fetal medicine specialists, fetal cardiologists, pediatric interventional cardiologists, anesthesiologists and radiologists. Institutional experience and expertise significantly influence the success rates and outcomes of FAV (Tworetzky et al., 2004). Notably, the Cardiovascular Institute from Hospital Internacional de Colombia (HIC) performed the first successful FAV in the country, marking a significant milestone in maternal-fetal healthcare. This groundbreaking procedure was carried out on a fetus with severe aortic stenosis, providing a new opportunity for life and improved health outcomes for both the mother and child.
The decision to perform FAV should be guided by strict selection criteria, which include fetal echocardiographic parameters predicting the likelihood of successful intervention and postnatal biventricular circulation. These criteria help identify fetuses that are most likely to benefit from the procedure while minimizing unnecessary risks (Friedman et al., 2018). Recent advancements in imaging technologies, such as high-resolution fetal echocardiography and MRI, have enhanced the diagnostic accuracy and procedural planning for FAV. These innovations have contributed to improved outcomes by allowing for more precise assessment of fetal cardiac anatomy and function, thereby facilitating better patient selection and procedural success (Pickard et al., 2020).
FAV is a promising intervention for modifying the course of severe aortic stenosis in utero, potentially preventing the progression to HLHS. Careful patient selection, institutional expertise and ongoing research are crucial to maximizing the benefits of this innovative procedure.
