Outcomes of Stent Implantation for Obstruction of Intracardiac Lateral Tunnel Fontan Pathways

Abstract

Factors associated with obstruction of the cavopulmonary pathway in patients with a lateral tunnel (LT) intracardiac Fontan connection and outcomes of percutaneous stent implantation for this complication have not been characterized. Between 1999 and 2011, 51 patients underwent stent implantation for LT pathway stenosis at a median age of 10.2 years and a median of 6.9 years after Fontan completion. Compared with control patients undergoing catheterization for other indications, patients had significantly higher inferior vena cava pressures (15.6 versus 13.7 mm Hg; P=0.007), but only 18 (35%) had a measurable pressure gradient in the catheterization laboratory. The morphology of the obstructions varied considerably and was not amenable to straightforward classification. Stenting increased mean diameter of the LT stenosis from 8.5 to 14.2 mm (P<0.001) and eliminated the pressure gradient when present. After stenting, 1 patient developed a significant new baffle leak that was treated with surgical Fontan revision 1.2 months later. A trivial baffle leak was observed in 1 other patient after stenting but required no treatment. Eight patients (16%) underwent successful redilation of the LT stent because of patient growth, symptomatic presentation, or during catheterization for other indications, but 1 developed a new baffle leak during redilation. It was possible to enlarge the narrowed LT baffle substantially in patients with a variety of forms of obstruction, with few adverse events. The physiological implications of LT narrowing and target size for stenting deserve further investigation.