Ann Pediatr Cardiol. Oct-Dec 2020;13(4):327-333.
doi: 10.4103/apc.APC_154_19. Epub 2020 Sep 21.
Free PMC article
Take Home Points:
- Fontan fenestration closure may be considered in patients with favourable hemodynamics.
- This retrospective review demonstrates that in the first few years after Fontan operation, using strict inclusion criteria there is an improvement in systemic saturations with no increase in the adverse events.
Commentary from Dr. Varun Aggarwal (Minneapolis, MN, USA), section editor of Congenital
Heart Disease Interventions Journal Watch: First reported in 1971 in the journal Thorax by Dr. Francis Fontan and Dr. Eugene Baudet on a patient with tricuspid valve atresia as a procedure to “transmit the whole vena cava blood to the lungs while only oxygenated blood returns to the left heart”. This operation has since been commonly referred to as ‘Fontan operation’ and has been performed in many children born with a variety of different congenital heart lesions. A significant physiological change in the postoperative period is sometimes complicated by low cardiac output syndrome and pleural effusions. Creation of a small connection between the Fontan conduit and the atrium can allow some right to left shunting across the fenestration and improve cardiac output decreased incidence of pleural effusions.
One of the commonly debated topics is the decision is ‘if and when’ to close these Fontan fenestrations. In this retrospective review by Thatte et al, patients who underwent fenestrated Fontan procedures from 2005 to 2015 were classified into three groups [Group A (n=42): those who underwent fenestration closure, Group B (n=10): fenestration closure deferred due to failure to meet the criteria for fenestration closure and Group C (n=150): patients not referred for cardiac catheterization as controls]. Criteria used for fenestration closure by authors included 1) anatomically unobstructed Fontan pathway with no significant decompressing systemic to pulmonary veno-venous collaterals; (2) baseline Fontan pressure ≤15 mmHg; (3) baseline cardiac index ≥2 L/min/m2; and (4) decrease in cardiac index ≤20% from baseline with test occlusion of the Fontan fenestration.
The cardiac catheterization procedure was performed at a median 28 months after Fontan operation for Group A and 59 months for group B. Acutely, the mean Fontan pressure increased from 13.1 ± 2.1 to 14.5 ± 2.1mmHg in Group A and 14.6 ± 1.5 to 15.7 ± 2.2 mmHg in Group B (P = not significant). With test occlusion, cardiac index fell by 18.12% ± 15.68% in Group A and 33.75% ± 14.98% in Group B (P = 0.019). Interestingly the main difference in the two groups was the more pronounced fall in the cardiac index in Group B. At a median of 46-month follow-up, oxygen saturation increased significantly from 85.15% ± 6.29% at baseline to 94.6% ± 4.43% (P < 0.001) in Group A but with no statistically significant difference in the rates of plastic bronchitis, protein-losing enteropathy, or heart transplantation between the three groups. There was no reduction in the incidence of stroke observed in this cohort after closure of the Fontan fenestration.
Closure of Fontan fenestration using the above-mentioned criteria (within the first few years after Fontan operation) may result in an increase in systemic oxygen saturations without any increased incidence of long-term adverse outcomes like death, transplantation, protein losing enteropathy or plastic bronchitis. Whether this is true for patients further out from the Fontan operation remains a matter of discussion.
A digital subtraction angiogram of a patient with an extracardiac Fontan conduit demonstrating the persistent open Fontan fenestration (arrow) with right to left shunting. This patient had narrowing of the Fontan conduit as well as the left pulmonary artery which were stented, but the fenestration was left open at this cardiac catheterization.