Optimal criteria for transcatheter closure of Fontan fenestration: a single-center experience with a review of literature

Fenestration closure is considered to remove the persistent right-to-left shunt after the Fontan operation. However, the criteria for effective transcatheter closure of fenestration to avoid both acute and chronic Fontan failure have not been clarified. The objective of this study was to describe the hemodynamic data with test occlusion of the Fontan fenestration for patients who underwent a closure and those who did not, along with subsequent development of Fontan-associated diseases (FAD) at follow-up. This was a retrospective study conducted to assess the outcome of Fontan fenestration closure at Children's Hospital of Michigan over 27 years (1993-2019). The inclusion criteria were patients undergoing cardiac catheterization indicated for Fontan fenestration closure. Data were compared between the two groups: closure and non-closure patients. Baseline characteristics and hemodynamic variables with the fenestration occlusion test were analyzed. The primary outcome was the development of composite events of death/transplant, deteriorated New York Heart Association class symptoms, or FAD. Among the 38 patients who were brought to the catheterization laboratory, 33 received fenestration closure and 5 did not. On a median follow-up of 3.4 years (range, 1 month-12.6 years), the incidence of primary adverse outcomes was 13% (5/38). The incidence of primary outcome was significantly higher in the non-closure group (60% vs. 6%, p < 0.01). The non-closure group had a higher incidence of moderate or severe atrioventricular valve regurgitation, New York Heart Association class III symptoms, use of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, furosemide use, and sildenafil use. The multivariable logistic regression model showed that the hemodynamic variables associated with the non-closure group were mean left atrial pressure (odds ratio 1.74, p < 0.05) and change of mean Fontan pressure at the balloon occlusion (odds ratio 2.2, p < 0.05). The judgment of fenestration closure appeared appropriate in our cohort. Fontan fenestration closure may not be advisable in cases with a high baseline left atrial pressure or a significant increase in Fontan pressure on balloon occlusion testing.