Influence of fenestration on long-term Fontan survival

Fenestration in the total cavopulmonary connection system may improve the outcome of patients with significant risk factors for Fontan haemodynamics. Our study aims to analyse the difference in long-term survival between non-fenestrated and fenestrated patients.

All consecutive patients (n = 351) who underwent total cavopulmonary connection between 1992 and 2016 were identified. Six early deaths were excluded resulting in a group of 345 patients. Median (interquartile range,) length of follow-up was 14.4 (7.1-19.7) years. Freedom from the composite endpoint of death, total cavopulmonary connection take-down or indication for a heart transplant was analysed.

Fenestration was absent in 237 patients (68.7%, Group 1), was created and closed later in 79 patients (22.9%, Group 2), and remained open in 29 patients (8.4%, Group 3). Mean survival probability until composite endpoint was 97.1 and 92.9% at 10 and 20 years, respectively. Patients with patent fenestration had worse survival (p < 0.001) as compared to both the non-fenestrated and fenestration closure groups. Despite a similar outcome, exercise capacity was lower in Group 2 than 1 (p = 0.013). In 58 patients with interventional fenestration closure, Nakata index was lower at the time of closure than pre-operatively, and both the pressure in the circuit and oxygen saturation in the aorta increased significantly (p < 0.001).

Patients with persisting risk factors preventing fenestration closure are at higher risk of reaching the composite endpoint. Patients after fenestration closure have the worse functional outcome; their survival is, however, not different from the non-fenestrated group.