Prevention of Left Ventricular Outflow Tract Obstruction During High-Risk Transcatheter Mitral Valve Replacement.

BACKGROUND: Transcatheter mitral valve replacement can carry a left ventricular outflow tract (LVOT) obstruction in patients with small neo-LVOT. CASE SUMMARY: A 74-year-old woman with a degenerated 27-mm surgical mitral bioprosthesis presented with severe symptomatic mitral stenosis and biventricular failure. She was deemed high risk for redo surgery. After heart team discussion, she underwent extracorporeal membrane oxygenation-supported valve-in-valve transcatheter mitral valve replacement with balloon-assisted translocation of the anterior mitral leaflet modification and intraleaflet deployment of a 26-mm balloon-expandable valve using a left ventricular pacing guidewire and 13-F steerable sheath. DISCUSSION: Mechanical circulatory support combined with leaflet modification may enable transcatheter mitral valve replacement in patients with high-risk anatomy and prohibitive surgical risk. TAKE-HOME MESSAGES: Balloon-assisted translocation of the anterior mitral leaflet modification with mechanical circulatory support may be feasible in selected patients at high risk of LVOT obstruction. A left ventricular pacing guidewire can facilitate valve delivery and rapid pacing while avoiding right ventricular instrumentation, while a steerable sheath supports controlled traversal of a calcified leaflet.