Left ventricle-right atrium (LV-RA) connection is a rare cardiac anomaly that allows blood to flow from the left ventricle to the right atrium. This condition may be congenital or acquired. Congenital forms, classically referred to as a Gerbode defect, manifest as a malformation in the membranous atrioventricular septum (1). In contrast, acquired cases often develop secondary to an iatrogenic injury. Postoperative LV-RA shunt is a recognized complication following a ventricular septal defect (VSD) repair, especially when it involves manipulation of the membranous septum or tricuspid valve apparatus leading to a leaflet defect.

Defects of valve leaflets are typically seen in high pressure chambers of the heart, i.e., the mitral or aortic valve. Their susceptibility towards infective endocarditis presents as the most frequent cause (2). In cases where the tricuspid valve is affected, defects such as leaflet perforations are often associated with implanted pacemaker or defibrillator leads (3, 4). This results in tricuspid regurgitation, and ultimately progress to right-sided heart failure, if left unrepaired.

The current mainstay treatment option for valve leaflet defects is surgery. However, successful percutaneous transcatheter closures have been documented in multiple cases of the mitral valve, and should be considered as a viable alternative, especially in high-risk populations (5–9). The scarcity of reports on LV-RA connection due to tricuspid valve defects highlights the critical need to explore its safety and feasibility. In this report, we present a pediatric case of percutaneous transcatheter device closure of an LV-RA connection following a VSD surgical closure.

To our knowledge, this is the first pediatric retrograde Konar-MF closure of an LV-RA connection due to a tricuspid valve defect accompanied with a residual MSA. Tricuspid defects, particularly perforations, have largely been associated with pacemaker or defibrillator lead implantation. However, symptoms manifestation from such complications may take up to years after the procedure, making it difficult to diagnose (4). In the present case, the patient was admitted following a surgical VSD closure one year prior. There was no history of intracardiac device implantation, infective endocarditis, or other congenital abnormalities. This leads to the speculation that the tricuspid leaflet defect may be due to an iatrogenic injury from his past VSD correction.

There are alternative etiologies to consider for an LV-RA connection given the absence of echocardiographic data from the previous VSD closure. If the underlying cause is a congenital malformation, then a Gerbode defect is a plausible differential diagnosis due to its overlapping features. According to the classification described by Winter et al. (1), an indirect (type II) Gerbode defect would best fit the patient's condition. This is characterized by an interventricular septal defect located inferior to the tricuspid leaflet, with a tricuspid valve abnormality such as leaflet perforation. However, the pre-procedural TEE in this case demonstrated an isolated tricuspid leaflet defect with a residual MSA, resulting in a direct shunt from the left ventricle to the right atrium without residual VSD. These findings suggest that an iatrogenic tricuspid leaflet defect secondary to the prior surgical intervention is still the most likely explanation.

Surgery remains the established treatment for valve leaflet defects, either through valve replacement or pericardial patch repair (10–12). Similar to other surgical interventions, this carries the risk of complications, particularly to more vulnerable populations such as pediatrics. Advancements in current technologies have allowed percutaneous closure as a more minimally invasive alternative. Unfortunately, reported cases were limited only to the mitral valve and on adult patients (5–9). Compared to a surgical repair, transcatheter closure of heart defects offers notable benefits. Although a higher success rate was observed in open-heart patients, percutaneous closure of heart defects resulted in less intensive care unit and hospital length of stays. Non-surgically-treated patients also require less blood transfusions and significantly shorter ventilation time (13–16).

In the present case, the patient's family refused another invasive surgery, therefore the cardiac team settled on a non-surgical approach via transcatheter closure. This is the first documented use of Konar-MF closure with retrograde transarterial approach on an LV-RA connection. Occluder implantation in heart valves inherently carries risks, however published data on transcatheter tricuspid valve implantation (TTVI) in children is scarce. A review by Sazzad et al. (17), with only a single pediatric case of a 12-year-old patient, demonstrated that device placement may interfere with leaflet motion or result in paravalvular leakage, causing persistent or new tricuspid regurgitation. In another recent study, transcatheter tricuspid valve replacement (TTVR) proved to significantly reduce tricuspid regurgitation, with intraprocedural success rate up to 97.2% (18). Follow-up outcomes showed that patients who underwent TTVR had a 4% mortality rate at 30-days and a 1-year mortality rate of 9%, which is significantly lower compared to a surgical repair (19). Embolization or device migration is also a rare yet serious complication, with 3.6% incidence in post-TTVI reports (17). This is important for devices implanted in soft tissues such as the tricuspid valve leaflet, which makes secure anchoring more difficult. Despite these considerations, post-procedure evaluation of the current case demonstrated favorable outcomes, which aligns with prior reports on isolated transcatheter occluder closure of mitral valve defects (6, 20).

TEE played a pivotal role in providing optimal visualization of the LV-RA connection as well as effectively guiding the wire and catheter to cross the defect. Although transcatheter closure of valve defects is generally performed via an antegrade approach, the retrograde approach helps avoid resistance of the turbulent jet flow. In our case, this facilitated catheter navigation across a small defect located within the highly mobile tricuspid valve leaflet. Moreover, the presence of the patient's MSA enabled the catheter to cross the defect from the left ventricle directly into the right atrium. The Konar-MF VSD Occluder No. 6/8 mm was selected primarily due to its double-disc feature, as well as the limited availability of other devices, such as ASD occluders with particular sizes, at our institution. In addition, its relatively soft structure minimizes potential interference with valvular function.

Extended patient follow-up is crucial to monitor the long-term safety and efficacy of transcatheter device closure of tricuspid leaflet defects. Reports on children with implanted heart valve prostheses have shown an infective endocarditis risk of up to 1.6%. This is highest within the first 6 months after device placement, but late cases after several years may occur (21). As there is currently no large-scale, long-term studies on closure of leaflet defects, regular evaluation is needed to assess the possibility of residual shunts, conduction disturbances, and device embolization.

This report describes a single case with a follow-up period of less than one year. Further studies with larger cohorts and extended follow-up durations are warranted to validate the safety, efficacy, and long-term outcomes of transcatheter tricuspid leaflet repair in pediatric patients.

Percutaneous transcatheter device closure of an LV-RA connection in pediatrics is a feasible alternative to surgery using a retrograde technique. For long-term outcome, an extended follow-up is necessary to evaluate both the patient's clinical condition and device placement.