Superior Vena Cava Inflow Following Repair for Anomalous Right Pulmonary Venous Drainage in Children.

Risk of superior vena cava (SVC) obstruction following repair of anomalous right upper pulmonary veins in children is unclear. The incidence and outcome of subclinical obstruction remained unknown. Retrospective single institutional study (07/1993-02/2017) in a pediatric population (N = 42, median age 3.9-year, range 0.1-15.3 years). 33 (79%) children had repair without SVC translocation ("non-Warden") and 9 (21%) had Warden-type surgery. Echocardiographic SVC obstruction was defined as (I) turbulent flow across SVC and (II) continuous flow pattern without return to baseline velocity (0 m/s); severe obstruction was defined as loss of distinct biphasic profile ± mean gradient ≥ 5 mmHg. 3 (7%) patients required intra-operative revision due to obstruction (non-Warden: 1, Warden: 2). After discharge, 2 (5%) patients required reintervention (3 and 6-month post-op) for severe symptomatic obstruction (non-Warden: 1, Warden-type: 1). Both patients responded to balloon angioplasty with symptomatic resolution (one required repeat catheter reintervention). 10 (24%) patients had subclinical echocardiographic obstruction (2, 22% Warden vs. 8, 24% non-Warden; p = 1.0; 8 of 10 patients had mild gradient), which resolved and remained well without reintervention. At follow-up (mean 7.2-year, range 0-23 years), all patients were alive. Freedom from SVC reintervention at 10 and 20-year is 95% (97% at 10, 20-year in non-Warden and 89% at 5, 8-year in Warden-type group; log-rank p = 0.34). Surgical repair for anomalous right upper pulmonary veins is associated with risk of SVC obstruction in children. The need for reintervention for severe obstruction is rare at late follow-up. Patients with subclinical obstruction remain asymptomatic and demonstrate echocardiographic improvement.