Transcatheter Stenting to Restore Cross-Sectional Area of Extracardiac Fontan Conduits

Reduction in cross-sectional area (CSA) of extracardiac Fontan conduits (EFC) is a known complication of the Fontan operation. Relief of obstruction is crucial for optimal Fontan physiology. The aim of this study is to describe technical aspects and outcomes of EFC stenting and short-term follow-up.

A retrospective study was performed of patients who underwent stent implantation in EFCs with reduced CSA from July 2011 to February 2024. The expected conduit CSA was calculated based on the implanted EFC diameter. The minimum CSA before and after stent implantation was calculated. The minimum EFC diameter and CSA were compared pre- and post-intervention. Data are presented as median [interquartile range].

Sixty-five patients with reduced EFC CSA underwent stent implantation (median age: 13.3 [12.5, 16.8] years, median weight: 49.5 [41.6, 65.4] kg). Forty-seven (72.3%) catheterizations were performed for routine surveillance. In the 63 patients with a known original EFC size, the median reduction in EFC CSA was 36.0 [29,46] %. The minimum CSA was significantly smaller than the expected CSA (157.2 [133.7, 180.1] mm² vs. 254.5 [254.5, 254.5] mm², p < 0.0001). Including all patients the minimum EFC diameter and CSA were 12.5 [11.6, 13.4] mm and 153.8 [133.7, 179.7] mm², respectively. Following stent placement EFC diameter and CSA improved to 16.8 [16.2, 17.8] mm (p < 0.0001) and 234.8 [223.4, 269.2] mm² (p < 0.0001), respectively. The EFC CSA was 96.8 [89.2, 108.4] % of the expected CSA based on the original EFC diameter. In 24 (36.9%) patients the EFC CSA following stent placement was greater than the expected CSA. There were nine complications in total, of which two were related to EFC stenting.

Stent implantation can safely and effectively restore EFC CSA. In select cases, conduits can be expanded beyond the stated diameter.