Right ventricular outflow tract obstruction in recipient twins of twin-to-twin transfusion syndrome: 13 years of single-center data and literature review.

BACKGROUND

To investigate the characteristics of right ventricular outflow tract obstruction (RVOTO) in recipient twins of twin-to-twin transfusion syndrome (TTTS), including its prevalence, perinatal outcomes, and the impact of fetoscopic laser coagulation (FLC) on postnatal RVOTO status.

METHODS

This retrospective study included recipient twins of TTTS treated with FLC at the Asan Medical Center between January 2011 and December 2023. Among those diagnosed with RVOTO, the recipient twins were categorized into two groups based on postnatal outcomes: RVOTO improvement versus persistence. Prenatal ultrasound findings and neonatal outcomes were compared between the groups. To identify the predisposing factors for RVOTO, the entire recipient population was divided into RVOTO and non-RVOTO groups, followed by univariate and multivariable logistic regression analyses.

RESULTS

Among the 284 TTTS cases, 24 recipient twins (8.5%) were diagnosed with RVOTO. RVOTO improved following FLC in 7 cases (29.2%). In the remaining 17 cases with persistent RVOTO, six were stillbirths. In the 11 survivors, five had mild RVOTO and required no intervention, while six underwent intervention (four with balloon valvuloplasty and two with surgical correction). Multivariate analysis identified the initial Quintero stage (odds ratio [OR] 2.64), pulsatile umbilical vein (OR 3.44), and tricuspid regurgitation (OR 30.66) as significant independent risk factors for RVOTO.

CONCLUSIONS

RVOTO is a relatively common cardiac complication in advanced TTTS. Timely FLC may lead to postnatal improvement. Serial ultrasound assessment is essential for early detection, risk stratification, and individualized counseling.