During early morphogenesis of the heart, an obstructive lesion can lead to a complex cardiac malformation at the end of pregnancy in both the right and left heart. Valvular aortic stenosis (AS) in the left heart of mid-gestation fetuses can progress to hypoplastic left heart syndrome (HLHS), which can result in congestive heart failure and intrauterine death. Early intracardiac intervention using valvuloplasty of the fetal aortic valve has the potential to eliminate this obstructive lesion, and rescue the left ventricle, preventing progression of critical AS to HLHS and avoiding postnatal univentricular circulation.
This study was designed to assess the outcome of 24 cases of aortic valvuloplasty performed in fetuses with critical AS with respect to indications, success rate, complications, and postnatal outcome. Between 2001 and 2009, 23 fetuses diagnosed with critical valvular AS underwent aortic valvuloplasty using a transabdominal ultrasound-guided approach. The gestational ages of these fetuses ranged from 21 to 32 weeks. The procedure was repeated in 1 fetus with a failed procedure after 7 days; thus, 24 interventions were performed in 23 fetuses.
Of the 24 procedures, 16 (66.7%) were technically successful; intrauterine death occurred in 1 of the 16 successful valvuloplasties. After an initial learning phase, the success rate improved during the last 5 years to 78.6% for the last 14 interventions. Of the 15 successfully treated live-born fetuses, 10 (66.7%) achieved a postnatal biventricular circulation, and 5 (33.3%) were born with a univentricular circulation. Hydrops was present in 4 fetuses as a late sign of congestive heart failure and resolved within 5 weeks of successful intrauterine intervention; all had a postnatal biventricular outcome. Of the 8 unsuccessful interventions (8/24, 33%), 1 was repeated successfully with a biventricular outcome, 2 resulted in intrauterine death, and 5 were born with HLHS.
These findings show that fetal aortic valvuloplasty in selected fetuses with critical AS and evolving HLHS can be performed successfully and achieve a biventricular outcome in two-thirds of patients. Critical factors for success include careful patient selection and an experienced interventional team.