3D TEE-Aided FEM Biomechanical Modeling for Planning Mitral Valve Repairs

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DESCRIPTION (provided by applicant): Most cardiac operations are reconstructive by nature and require an accurate understanding of the heart's complex three-dimensional structure. Since most cardiac reconstructive operations are performed on a flaccid empty heart under cardiopulmonary bypass, it is challenging for cardiac surgeons to accurately predict how their surgical modifications will behave under physiologic conditions. This uncertainty often leads to prolonged operations, suboptimal corrections, and technical failures which can adversely impact clinical outcomes. Although recent advances in cardiac imaging have provided remarkably accurate and detailed views of cardiac structural pathologies, a way to exploit these capabilities in better planning complex reconstructive operations has not been developed. Real-time three-dimensional (3D) transesophageal echocardiographic (TEE) imaging provides superior structural and functional assessments of the heart not readily achievable with conventional two-dimensional echocardiography. In this proposal, we seek to exploit 3D TEE imaging data to develop a computational biomechanical model that would permit cardiac surgeons to preoperatively simulate and predict functional outcomes associated with different mitral reconstructive options. We hypothesize that (1) an accurate computational finite-element model (FEM) of the mitral valve apparatus exploiting patient-specific 3D TEE imaging data can be developed and (2) hemodynamic and functional consequences of "virtual" structural modifications of this biomechanical model can be used for the purposes of preoperative surgical planning. Our Specific Aims are: Specific Aim 1: We will perform preliminary 3D TEE image analysis. We will refine our existing 2D TEE image analysis algorithms and extend them to 3D TEE for computing patient-specific 3D motion and structure information through automated segmentation, mesh generation, optical flow estimation, and dynamic tracking. Specific Aim 2: We will develop a modifiable computational biomechanical finite-element model to accurately predict the mitral valve closure behavior resulting from a virtual surgical reconstruction. Specific Aim 3: We will carefully validate our computational model of the mitral valve apparatus. We will compare computed, predicted and observed motion of the mitral valve system, and intracardiac blood flow patterns obtained in clinical studies involving humans, and phantom and porcine models. We believe that more predictive preoperative planning would promote more technically sound cardiac and non-cardiac reconstructive operations such as mitral valve repair. PUBLIC HEALTH RELEVANCE: We propose to use patient-specific 3D TEE imaging data to develop an accurate computational finite- element model (FEM) of the mitral valve apparatus. We hypothesize that hemodynamic and functional consequences of "virtual" structural modifications of this biomechanical model would be useful in the preoperative surgical planning of mitral valve repairs. We believe that more predictive preoperative planning would promote more technically sound reconstructive operations.