Functional Dynamic In-Vivo Stresses of the Mitral Valve Anterior Leaflet

Although mitral valve (MV) repair surgeries are commonly performed, their long-term durability has not been completely satisfying. In most cases, failure was a result of disruption at the leaflet, chordae, or annular suture lines. These failure modes suggest excessive stress and the resulting tissue damage as etiologic factors. The purpose of this study was to develop a method to better estimate functional dynamic in-vivo stresses in the MV anterior leaflet (AL) midsection. The stress was computed from the dynamic in-vivo strain measured experimentally. Numerous in-vivo and in-vitro studies (e.g. [3, 4]) have been conducted to quantify MV dynamic strain. We used in-vivo strain data obtained from our well-established ovine model [4]. To calculate the in-vivo strain, we employed the actual unloaded state of the tissue as the reference frame, measured for the first time in this study. The AL stress was then computed using our nonlinear structural constitutive model [5].