A Surgeon’s Toolkit for Mitral Valve-Induced Left Ventricular Outflow Tract Obstruction With Minimal Septal Hypertrophy

Mitral valve leaflet and subvalvular apparatus abnormalities can cause left ventricular outflow tract obstruction in the absence of septal hypertrophy. The authors discuss different techniques to address this situation, based on two key principles: modifying the effects of altered flow vortices that change the position of mitral valve leaflets with relation to the outflow tract and restoring posterior coaptation of the leaflets. The preoperative workup is detailed, including echocardiography and cardiac MRI to assess leaflet and papillary muscle anatomy. Various repair techniques are described, including anterior leaflet shortening, reduction of posterior leaflet height, papillary muscle head reorientation and partial resection, as well as mitral valve replacement when necessary.