Clinical Benefit of Percutaneous Treatment of Fontan Pathway Obstructions

<b>Background/Objectives:</b> Fontan pathway obstructions are a common complication during long-term follow-up after Fontan surgery. The clinical or hemodynamic benefit of percutaneous treatment of Fontan stenoses is poorly understood. In this study we analyzed the feasibility and clinical effects of percutaneous treatment of Fontan pathway obstructions. <b>Methods:</b> From April 2019 to December 2024 35 Fontan patients received percutaneous treatment of Fontan pathway obstructions by stent implantation. Indications for treatment included clinical signs of lower venous congestion or PLE and/or a moderate-to-severe morphologic pathway stenosis independent of clinical sequelae. Median follow-up time after the intervention was 1.5 years [IQR 0.7; 2.2]. <b>Results:</b> Median patient age was 20.3 years [IQR 16.3; 26.8]. Interventional success was defined as a significant increase in median indexed Fontan conduit cross sectional area and was achieved in all patients by expanding from 98.4 mm²/m² [IQR 80.7; 115.5] to 145.1 mm²/m² [IQR 134.8; 167.0, <i>p</i> < 0.001]. In symptomatic patients, a significant clinical improvement was detected 6 months after the intervention including an amelioration of physical capacity assessed by NYHA classification (<i>p</i> = 0.039) and cardiopulmonary exercise testing (VO_2peak; <i>p</i> = 0.025). Global assessment of Fontan-associated liver disease (FALD) showed improvement during follow-up (<i>p</i> = 0.035). No peri- or postprocedural complications occurred. <b>Conclusions:</b> Percutaneous treatment of Fontan pathway obstruction has a high interventional success rate with a significant increase in indexed cross-sectional area. During follow-up, improvement of patients' clinical condition and global signs of FALD were observed. The impact of percutaneous Fontan pathway obstruction relief on reversing or delaying the progression of FALD requires further investigation.