Transcatheter interventions in patients with a Fontan circulation: Current practice and future developments

Abstract

The Fontan operation represents the last of multiple steps that are offered a wide range of congenital cardiac lesions with a single ventricle (SV) physiology. Nowadays this surgical program consists of a total cavopulmonary connection (TCPC), by anastomosing systemic veins to the pulmonary arteries (PAs), excluding the right-sided circulation from the heart. As a result of imaging, surgical, percutaneous, and critical care improvements, survival in this population has steadily increased. However, the Fontan physiology chronically increases systemic venous pressure causing systemic venous congestion and decreased cardiac output, exposing patients to the failure of the Fontan circulation (FC), which is associated with a wide variety of clinical complications such as liver disease, cyanosis, thromboembolism, protein-losing enteropathy (PLE), plastic bronchitis (PB), and renal dysfunction, ultimately resulting in an increased risk of exercise intolerance, arrhythmias, and premature death. The pathophysiology of the failing Fontan is complex and multifactorial; i.e., caused by the single ventricle dysfunction (diastolic/systolic failure, arrhythmias, AV valve regurgitation, etc.) or caused by the specific circulation (conduits, pulmonary vessels, etc.). The treatment is still challenging and may include multiple options and tools. Among the possible options, today, interventional catheterization is a reliable option, through which different procedures can target various failing elements of the FC. In this review, we aim to provide an overview of indications, techniques, and results of transcatheter options to treat cavopulmonary stenosis, collaterals, impaired lymphatic drainage, and the management of the fenestration, as well as to explore the recent advancements and clinical applications of transcatheter cavopulmonary connections, percutaneous valvular treatments, and to discuss the future perspectives of percutaneous therapies in the Fontan population.

Keywords: Fontan procedure; collaterals embolization; percutaneous interventions; percutaneous valve; stents.

FIGURE 1

Angiography of inferior vena cava, lateral view. Stenosis at the proximal anastomosis (white asterisk) of a Fontan conduit, 15 years after intervention. FC, Fontan conduit; IVC, inferior vena cava; PA, pulmonary arteries.

FIGURE 2

Patient with a Fontan failure who underwent coil embolization of both mam-mary arteries (white asterisks) and stenting of right and left pulmonary arteries (with arrows).

FIGURE 3

Effect of various degrees of pulmonary bypassing in a Fontan circuit on systemic output (thick line), saturation (dotted line), and systemic venous congestion (thin line). A “good Fontan” (green or lighter lines) with low neoportal resistance has a cardiac output (solid green line) of about 80% of normal for BSA, with high saturations (dotted green line) and a slightly raised CVP (thin green line). The “bad Fontan” (red lines) with a high neoportal resistance has comparable saturations (dotted red) but with a very low output (solid red) in the presence of a high CVP (thin red). Partial bypassing of the Fontan portal system by a fenestration consistently increases systemic output and lowers venous congestion but may give rise to clinically intolerable degrees of cyanosis (effects of fenestration size can be viewed at the bottom right of the graph). BSA: body surface area; CVP: central venous pressure. Adapted with permission from Gewillig et al. (28).

FIGURE 4

Fenestration closure using vascular plugs. (A) Lateral angiogram of a Fontan conduit showing a fenestration (white arrow) between the conduit and the single atrium. (B) Lateral angiogram following fenestration closure using an Amplatzer Vascular Plug II (Abbott) (black arrow). FC, Fontan conduit; SA, single atrium.

FIGURE 5

Fenestration closure using covered stents. (A) Lateral angiogram of a Fontan conduit showing a fenestration (white arrow) between the conduit and the single atrium. (B) Lateral angiogram following fenestration closure using a covered CP stent (Numed) implantation within the conduit. FC, Fontan conduit; SA, single atrium.

FIGURE 6

Liver lymphangiography in a Fontan patient with protein losing enteropathy: note the dilated lymphatics in the peri-portal area draining toward the gut (white arrow).

FIGURE 7

Thoracic duct lymphography in a Fontan patient with plastic bronchitis: note the dilated thoracic duct with multiple and bilateral leaks toward the lungs (white arrow).

FIGURE 8

Angiographic images from 5-years-old boy who underwent transcatheter Fontan completion. (A,B) Simultaneous frontal and lateral injections of the right atrium and Glenn showing the distance between the two circuits. Please notice the clips at SVC and IVC levels; (C) lateral view of the connection created with a needle between Glenn and RA; (D) lateral angiogram after perforation showing no significant bleeding and SVC to RA connection.

FIGURE 9

(A) Ballooning of the neo-connection to help the advancement of IVC sheath to the Glenn; (B–D) angiograms done after the completion of the intracardiac Fontan with covered stents. IVC flow is now draining from IVC to PAs without restriction. The for-ward flow (RV to PA) was occluded by positing a covered stent from RPA to LPA.

FIGURE 10

Percutaneous atrioventricular valve edge-to-edge repair procedure in a patient with Fontan Circulation. (A) Computed tomography scanner showing the Fontan conduct (FC) connecting the inferior vena cava to the pulmonary artery, the single atrium (SA), the single atrioventricular valve (SAV), and the single ventricle (SV); (B) transesophageal echography with color Doppler showing the high-grade regurgitation of the atrioventricular valve (AVR); (C) echo guided puncture of the Fontan conduct connecting the inferior vena cava and the left pulmonary artery; (D) result after Mitra-clip (MC) implantation responsible for a dramatic decrease of the AVR.

FIGURE 11

Melody valve implantation in a patient with a Fontan circulation. (A) Basal angiogram of the extracardiac conduit; (B) angiogram showing a competent Melody valve; (C) angiogram showing good forward flow between inferior vena cava and pulmonary arteries; (D) intra-cardiac echography 1 after implantation, showing competent Melody valve and perfect leaflets coaptation (white arrow).