Severe Left Ventricular Outflow Obstruction by Native Anterior Mitral Leaflet After Bileaflet Preserving Mechanical Mitral Valve Replacement

Abstract

Left ventricular outflow tract obstruction (LVOTO) after mitral valve replacement (MVR) is a challenging complication. This case report describes a 70-year-old female who developed systolic anterior motion (SAM) secondary to an unresected anterior mitral leaflet several years following leaflet-preserving mitral valve replacement, with associated heart failure and tricuspid regurgitation. Surgical intervention included trans-aortic resection of the obstructing anterior mitral leaflet and chordae without re-replacing the mitral valve, followed by tricuspid valve bicuspidization. The transaortic resection approach was chosen in this case due to its ability to effectively address SAM by directly accessing and resecting the anterior mitral leaflet and preferred over others to minimize surgical complexity while adequately managing the LVOT obstruction. The postoperative course and management are discussed. Surgical strategies to prevent LVOTO and SAM are reviewed, highlighting the importance of proper leaflet management and valve orientation to ensure optimal patient outcomes.

Keywords: left ventricular outflow tract (lvot) obstruction; mitral valve replacement; pulmonary hypertension; systolic anterior movement (sam); tricuspid regurgitation.