Transcatheter closure of the right atrioventricular valve in a double-inlet left ventricle patient following fontan operation

Abstract

In this new case study, we report a successful percutaneous transcatheter right atrioventricular (AV) valve closure procedure using a patent foramen ovale occluder (Occlutech International AB, Helsingborg, Sweden) in an 11-year-old boy who had previously undergone a Fontan procedure and surgical right AV valve closure for double-inlet left ventricle, hypoplastic right ventricle, ventricular arterial discordance and coarctation of the aorta and developed severe right AV valve regurgitation during follow-up. We aimed to share our experience regarding the difficulties encountered during the procedure.

Fontan circulation, first described by Fontan and Baudet,^[1] has significantly advanced the management of complex congenital heart disease with single-ventricle physiology. Although the Fontan procedure has markedly improved survival and clinical outcomes, it is associated with long-term hemodynamic alterations and procedure-related complications. Among these, atrioventricular (AV) valve regurgitation is particularly critical, as it may lead to progressive heart failure, reduced exercise tolerance, and impaired quality of life in Fontan patients.^{[2, 3]}

Percutaneous transcatheter valve interventions have emerged in recent years as a promising minimally invasive option for patients with severe AV valve regurgitation. These procedures offer several benefits over conventional surgical valve repair or replacement, including lower procedural risk, shorter recovery time, and improved postoperative quality of life. However, despite their increasing use in adults, there is limited literature describing transcatheter approaches for AV valve insufficiency in patients with Fontan physiology. Ongoing advancements in transcatheter technologies now enable pediatric and interventional cardiologists to consider more personalized^[4] and targeted therapies for this complex patient group.

Here, we present a successful percutaneous transcatheter right AV valve closure using a patent foramen ovale (PFO) occluder (Occlutech International AB, Helsingborg, Sweden) in an 11-year-old boy with a history of Fontan operation and prior surgical right AV valve closure for double-inlet left ventricle, hypoplastic right ventricle, ventriculoarterial discordance, and coarctation of the aorta. The patient developed severe right AV valve regurgitation during follow-up. This case highlights the technical challenges encountered during the procedure and provides insight for clinicians managing similar patients.

Case Report

The patient had a complex congenital cardiac anatomy characterized by double-inlet left ventricle, inlet ventricular septal defect, hypoplastic right ventricle, ventriculoarterial discordance, moderate-to-severe right AV valve regurgitation, and coarctation of the aorta. At 2 months of age, he underwent pulmonary artery banding and surgical repair of the aortic coarctation. Approximately five years later, he underwent multiple procedures in the same operative session, including a bidirectional Glenn shunt, Fontan operation using a 19-mm polytetrafluoroethylene (PTFE) conduit without fenestration, closure of the main pulmonary artery, and surgical right AV valve closure with enlargement of both atrial and ventricular septal defects.

Postoperative echocardiography initially showed mild right AV valve regurgitation. However, over a four-year follow-up period, the regurgitation progressively worsened to a severe degree, leading to symptoms such as exercise intolerance and episodes of syncope.

Given the elevated surgical risk associated with reoperation, percutaneous closure of the right AV valve was selected as the preferred treatment strategy. The procedure was performed under general anesthesia with transesophageal echocardiographic guidance. Using a percutaneous approach, 6F sheaths were inserted into the right femoral vein and left femoral artery.

Preprocedural hemodynamic measurements were as follows: aortic oxygen saturation, 96%; right ventricular (RV) pressure, 110/2-10 mmHg; left ventricular (LV) pressure, 114/0-10 mmHg; main pulmonary artery pressure, 14 mmHg; and aortic pressure, 109/56 (mean 72) mmHg.

Transseptal conduit puncture was performed through the Fontan PTFE extracardiac conduit and the free wall of the right atrium using an 8F Mullins transseptal introducer sheath and a Brockenbrough curved needle (Medtronic, Minneapolis, USA), under transesophageal echocardiographic guidance. After several unsuccessful attempts to cross the right AV valve with standard catheters, the 8.5F Agilis NxT steerable sheath (Abbott) was successfully advanced through the valve into the left ventricle. A 0.035-inch extra-stiff guidewire was then positioned across the right AV valve into the ventricle.

The Agilis sheath was subsequently exchanged for an 8F Mullins long sheath, and a 23×25 mm Occlutech PFO device (Occlutech International AB, Helsingborg, Sweden) was selected for right AV valve closure, based on a measured valve diameter of 22 mm on transthoracic echocardiography (Video 1, Figures 1 and 2). The device was successfully deployed with no residual leakage observed on transesophageal echocardiography or fluoroscopy (Figure 1).

Figure 1.

a) Transthoracic echocardiographic image showing right AV valve regurgitation, b) Measurement of the atrial septal defect diameter, c) Transesophageal echocardiographic image of the right AV valve before closure, d, e) Two-dimensional and color Doppler transesophageal images after AV valve closure, f) Three-dimensional transesophageal image after AV valve closure.

AV: Atrioventricular.

Figure 2.

a) Cardiac anatomy imaged with simultaneous contrast injection through catheters in the Fontan conduit and right atrium, b) Transseptal puncture through the extracardiac Fontan conduit and right atrial free wall using an 8F Mullins transseptal introducer sheath and a Brockenbrough curved needle, c) Contrast injection after crossing the Fontan conduit to delineate atrial anatomy, d) Catheter advanced over the guidewire into the right atrium after loop formation, e) Closure of the right AV valve using the Occlutech PFO device, f) Final position of the PFO device after AV valve closure.

PFO: Patent foramen ovale; AV: Atrioventricular.

At the end of the procedure, the fenestration was intentionally left open to minimize Fontan circuit pressure while ensuring adequate early postoperative systemic oxygenation. Postprocedural hemodynamic measurements were as follows: aortic oxygen saturation, 94%; RV pressure, 100/0-8 mmHg; LV pressure, 102/0-6 mmHg; main pulmonary artery pressure, 13 mmHg; and aortic pressure, 100/49 (mean 69) mmHg.

The procedure was completed safely and effectively, leading to a marked improvement in the patient’s symptoms and overall quality of life. The patient was discharged on the third postoperative day without any complications. Warfarin therapy was initiated due to the presence of both the fenestration and the device positioned at the AV valve.

The patient has remained clinically stable during 20 months of follow-up. Transthoracic echocardiography confirmed complete closure of the right AV valve with no residual leakage and only mild regurgitation of the left AV valve. A 24-hour Holter electrocardiogram showed no abnormalities.

Discussion

AV valve regurgitation is a major risk factor for morbidity and mortality in patients with Fontan circulation. This condition increases systemic venous pressure and aggravates lymphatic dysfunction. Moreover, atrial dilatation secondary to regurgitation predisposes patients to atrial arrhythmias and progressive ventricular dysfunction. Over the years, several surgical techniques have been developed to manage valvular regurgitation, with partial annuloplasty and commissuroplasty being the most commonly employed. Valvuloplasty is another frequently^[2] utilized approach.However, selecting the optimal surgical strategy for an individual patient remains challenging due to the wide variability in cardiac anatomy.

Given the inherent complexity and uncertain outcomes of surgical repair, there is no definitive consensus on the preferred management of AV valve insufficiency in patients with double-inlet ventricles. Ando and Takahashi^[3] reported that approximately 28% of single-ventricle patients undergo valve repair or replacement during their lifetime.Some investigators, however, advocate for closure of the nondominant regurgitant valve in Fontan patients rather than repair or replacement.^{[5, 6]} Several studies have also shown that a substantial proportion of patients undergoing surgery for valvular regurgitation eventually require reoperation or become candidates for cardiac transplantation.^{[6, 7, 8]} Importantly, the risk of morbidity and mortality increases with each subsequent reoperation after a failed valve repair.

Given the challenges of surgically repairing the right AV valve, complete closure during the prior operation was attempted but could not be fully achieved, resulting in persistent regurgitation and symptomatic presentation. Considering the limitations and risks of additional surgical interventions, transcatheter AV valve closure was deemed a more appropriate strategy. We also hypothesized that the patch tissue used in previous surgeries would facilitate transcatheter valve closure compared with native AV valve tissue.

Accessing the AV valve required fenestration of the Fontan conduit. Initial attempts using standard techniques for patients with Fontan circulation failure were employed to reach the atria. Advancing the guidewire across the AV valve and into the ventricle posed a significant challenge, which was successfully overcome using the maneuverability of the Agilis catheter.

Another important consideration was the potential for device-related thrombus formation. The right AV valve measured 22 mm, and the smallest suitable device for complete closure was the 23×25 mm Occlutech PFO device. This device was selected because its two retention discs are connected by a 3 mm waist and feature a single central pin on the right atrial side. Additionally, the polyethylene terephthalate patches ensure complete closure after implantation, while the left atrial disc is single-layered without a hub, minimizing material on the LV side and thereby reducing thrombotic risk in Fontan circulation. To further mitigate this risk, the patient was started on warfarin therapy and has remained complication-free during one year of follow-up.

Management of severe AV valve regurgitation in patients with Fontan circulation remains challenging. In patients with double-inlet ventricles, transcatheter closure of the nondominant AV valve, rather than surgical intervention, represents a safer and more feasible approach. This strategy may play a critical role in preventing Fontan failure and limiting progressive deterioration of cardiac function.

Ethics

Informed Consent: Informed consent was obtained.

Supplementary Materials

Video 1

https://youtu.be/6LDumsEM0I8