Transcatheter mass extraction using the ŌNŌ retrieval device used as a global embolic protection device

Transcatheter extraction of intracardiac masses using the ŌNŌ retrieval system has recently emerged as a promising alternative to surgical excision, which remains the widely adopted management strategy. A 67-year-old female was diagnosed with a mass attached to the posterior mitral leaflet, protruding into the left ventricular outflow tract. A modified ŌNŌ retrieval approach successfully extracted the mass under continuous TEE and fluoroscopic guidance. Post-procedural imaging confirmed complete mass removal with preservation of valvular function. Cytopathology revealed extensive calcifications with a giant cell reaction. This is the second reported MICHIGAN procedure that demonstrates a novel transcatheter intervention based on technical adaptations to optimize mass retrieval while preserving valvular integrity, highlighting the evolving role of transcatheter mass extraction strategies. • The ŌNŌ retrieval system, combined with novel snaring techniques, enables safe and effective transcatheter extraction of intracardiac masses, even in anatomically challenging cases such as those involving posterior mitral leaflet lesions. • Stepwise removal with full-body embolic protection under direct TEE and fluoroscopic guidance to capture and retrieve masses for histopathological assessment is a viable option for large masses in patients unsuitable for surgical excision.