Clinical Benefit after Endovascular Treatment of Fontan Pathway Obstructions

Background: The introduction of a total cavopulmonary connection has significantly improved the survival of patients with univentricular heart disease. However, Fontan pathway obstructions are a common complication during long-term follow-up after Fontan surgery. The clinical or hemodynamic benefit of endovascular treatment of Fontan pathway obstruction is poorly understood. In this study, we analyzed the feasibility and beneficial clinical effects of endovascular treatment of Fontan connection obstructions.

Methods: From April 2010 to May 2024, a total of 30 pediatric and adult Fontan patients received percutaneous treatment of Fontan connection obstructions. Indications for percutaneous treatment were a moderate to severe morphologic obstruction of the Fontan connection combined with a measurable pressure gradient, a moderate to severe pre-stenotic dilatation of the inferior vena cava and/or hepatic veins or clinical symptoms such as recurring edema or ascites, elevated liver enzymes or sonographic signs of advanced liver fibrosis. In 25/30 patients (83.3%), obstruction relief was achieved by implantation of a bare Cheatham-Platinum stent, whereas in 5/30 patients (16.7 %) an Andra or a BeGraft stent was implanted, respectively. The mean follow-up after the intervention was 2.8 years (± 3.5).

Results: Mean patient age was 22.3 years (± 10.0) and the mean patient weight was 60.1 kg (1 ± 7.4). Interventional success was defined as a significant increase in mean Fontan connection cross-sectional area and was achieved in all patients by expanding from 166.2 mm²/m² (± 72.3) to 257.1 mm²/m² (± 44.8, p < 0.001). In symptomatic patients, a significant clinical improvement was detected 4 to 6 months after the intervention including regression of recurrent ascites, improvement in physical capacity assessed by NYHA classification (p = 0.014), and significant decrease of the liver enzyme gamma-glutamyl transferase (p = 0.031). No peri- or postprocedural complications such as stent dislocation, dissection or re-stenosis occurred.

Conclusion: Percutaneous treatment of Fontan connection obstruction has a high interventional success rate leading to a significant increase in cross-sectional area. In patients with clinical signs of lower venous congestion, a significant clinical improvement and the decrease of the liver enzyme gamma-glutamyl transferase were achieved. The impact of percutaneous Fontan connection obstruction relief on reversing or delaying the progression of Fontan-associated liver disease remains to be investigated in prospective studies.