BACKGROUND: The Fontan procedure, performed for univentricular heart, may also include the technique of percutaneous fenestration to create a small atrial septal defect (ASD) and a right-to-left shunt. The aim of this study was to evaluate the long-term effects of fenestration in adult patients who had a Fontan procedure for univentricular heart.

MATERIAL AND METHODS: Fontan surgery was performed in 39 patients, including 19 (49%) patients with fenestration (Group I), and 20 (51%) patients without the fenestration procedure (Group II). Laboratory tests in both groups included echocardiography, plethysmography, cardiopulmonary exercise testing, and 24-hour Holter monitoring.

RESULTS: Compared with patients in Group I, patients in Group II had a significantly increased level of N-terminal pro-brain natriuretic peptide (NT-proBNP) (p=0.04), alkaline phosphatase (ALP) (p=0.01) and a significant increase in frequency of atrial fibrillation (p=0.04). Patients in Group I had a significantly increased systemic ventricular ejection fraction (SVEF) (p=0.05) and increased heart rate (HR) (p=0.006), heart rate reserve (HRR) (p=0.02), ventilatory equivalent (VE) (p=0.01), and VO2 peak (p=0.05) on cardiopulmonary exercise testing (CPET). Renal, hematologic, and ventilatory parameters, and incidence of thromboembolism showed no significant differences between the groups.

CONCLUSIONS: Long-term follow-up of patients who underwent Fontan procedures with percutaneous fenestration had improved single ventricular function, lower NT-proBNP levels, improved exercise capacity, and reduced ALP levels. These findings indicate that percutaneous fenestration closure should be considered for adult patients who have undergone Fontan procedure for univentricular heart.

Keywords: Exercise Tolerance, Fontan Procedure, Heart Defects, Congenital