Biventricular Outcome Improves after In Utero Aortic Valvuloplasty in Fetuses with Critical Aortic Stenosis and Evolving Hypoplastic Left Heart Syndrome: An Analysis of 92 Aortic Valve Interventions in a Single Center

Objectives: To assess success rate and biventricular (BV) outcome at 1 year of age after successful in utero valvuloplasty in fetuses with critical aortic stenosis and evolving hypoplastic left heart syndrome.

Methods: A retrospective analysis of all fetuses who underwent in utero aortic valvuloplasty from December 2001 until January 2018 at our center was performed. Success was defined as a procedure, where a balloon with adequate size (90–120% of the diameter of the aortic valve) has been inflated at least once at the level of the aortic valve. BV outcome was defined as a two-ventricle circulation at the age of 1 year in the absence of elevated pulmonary artery pressure.

Results: A total of 92 fetal aortic valve interventions were performed in 77 patients with a success rate of 83.7% per intervention (77/92) or 87% per patient (67/77). In this group, there were seven fetal deaths with four being procedure related (pr). pr mortality improved in the recent period (2014–2018; 2/32 fetal deaths [1 pr]) compared with the early period (2001–2013; 5/35 fetal deaths [3 pr]).

Sixty successfully treated patients were live born, 27 in our center and 33 (55%) in different European centers. Neonatal death or comfort care occurred in four patients. Forty-two (73.7%) neonates were initially treated toward a BV circulation. After 28 days, 41/56 (73%) patients and at the age of 1 year, 32/47 (68%) patients were still alive with a BV circulation. Compared with a natural history cohort of fetuses with moderate or severe left ventricular depression and retrograde aortic arch flow, this number is significantly higher than the BV rate at the age of 1year in the natural history cohort who did not receive in utero treatment (10/35; p = 0.0007). When the group of patients born and treated in our center, where a more aggressive postnatal approach was chosen (Ross–Konno surgery), was compared with the rest, more patients became BV at the age of 1 year (73.9% [17/23] vs. 62.5% [15/24]) but not statistically significant (p = 0.5343).

Conclusion: Fetal aortic valvuloplasty can be performed with a high technical success and an acceptable intrauterine device rate which improved over time. Successful intervention has led to a significantly higher rate of patients with BV circulation compared with published natural history data.