TY  - EJOU
AU  - Kizilkaya, Mete Han 
AU  - Cakan, Boran 
AU  - Bicer, Mehmet 
AU  - Odemis, Ender 

TI  - Progressive Right Ventricular Outflow Tract Obstruction Following Perimembranous VSD Closure with Lifetech™ Konar-Multifunctional Occluder (MFO) Device: A Rare Case of Valve–Device Interaction
T2  - Structural and Congenital Heart Disease

PY  - 2026
VL  - 21
IS  - 1
SN  - 3071-1738

AB  - <b>Background:</b> Transcatheter closure of perimembranous ventricular septal defects (pmVSDs) with Lifetech™ Konar-Multifunctional Occluder (MFO) has demonstrated high procedural success and safety. However, long-term complications due to valve–device interaction are rarely reported. We describe a pediatric patient who developed progressive right ventricular outflow tract (RVOT) obstruction and severe tricuspid regurgitation 20 months after MFO closure, highlighting mechanisms, management, and outcomes. <b>Case Description:</b> A 13-year-old girl underwent successful MFO closure of a 6-mm pmVSD. Early follow-up showed trivial tricuspid regurgitation and mild subpulmonic stenosis. Pre-procedural imaging revealed right ventricular hypertrophy caused by long-standing jet-related turbulence from the pmVSD, with no indications of a double-chambered right ventricle. Initial follow-up was uneventful, but serial echocardiography revealed rising RVOT gradients and mild tricuspid regurgitation. Sixteen months later, she developed exercise intolerance with a 60-mmHg gradient, although device position remained stable without migration. At 20 months, severe obstruction necessitated surgery. Intraoperatively, the device was found to entrap the anterior and septal tricuspid leaflets, displace papillary muscles, and induce fibrotic remodeling at the device-valve interference. Surgical management included excision of fibrotic tissue, pericardial patch augmentation of the tricuspid valve, and Kay annuloplasty. The patient recovered uneventfully, and follow-up confirmed resolution of obstruction with preserved valve function. <b>Conclusions:</b> This case demonstrates a rare long-term complication of MFO closure, in which chronic leaflet traction and increasing perimembranous fibrosis led to significant RVOT obstruction. Careful evaluation of anatomical risk factors, including VSD rim shape and leaflet proximity, can help identify patients at higher risk. Although MFO closure of pmVSDs is effective and typically safe, rare late complications involving the tricuspid valve and RVOT may occur. Pediatric cardiologists should carefully monitor valve–device interactions during implantation, and any leaflet restriction should prompt repositioning of the device. Follow-up must be thorough, with particular attention to Doppler gradients. If progressive obstruction develops, prompt surgical intervention can restore valve function and normal blood flow, leading to favorable outcomes.
KW  - Perimembranous ventricular septal defect; Konar-Multifunctional Occluder (MFO); tricuspid valve injury; right ventricular outflow tract obstruction; pediatric cardiac surgery; case report

DO  - 10.32604/schd.2026.074189