SUMMARY

Restrictive annuloplasty rings are a standard mitral valve repair procedure for ischemic mitral regurgitation (MR), however there is a high incidence of recurrent MR. With this recurrent MR, there is a need to understand the restrictive effects from an annuloplasty on the MV leaflets. The first goal of this dissertation is to study the effects of annular dynamics on the mitral leaflets and its restriction. To accomplish this, an MV in vitro model with a dynamically contracting annulus will be designed and used to compare leaflet strain between varying contractile states. These, now, high-risk patients with failed MV repairs and replacements created a demand for percutaneous MV interventions. With no dedicated devices currently on the market, clinicians have resorted to placing transcatheter aortic valves (TAV) into mitral annular calcification (valve-in-MAC), failing mitral bioprosthetic valves (valve-in-valve), and failing mitral annuloplasty rings (valve-in-ring). Currently, there are no official clinical guidelines, and no quantitative engineering studies have been conducted to better understand performance and risks. Percutaneous laceration of the anterior mitral leaflet (LAMPOON) is a proposed proactive solution to the risk of left ventricular outflow tract (LVOT) obstruction. The second goal of this dissertation includes designing and performing in vitro experiments to evaluate and quantify benefits of LAMPOON on LVOT obstruction and thrombosis. These goals will provide insight into potential causes of recurrent MR with annuloplasty rings, and an in-depth quantitative assessment of the benefits of LAMPOON with transcatheter mitral valve replacements. These will better inform procedural guidelines and medical device design, as well as provide further insight into MV biomechanics and advanced platforms for future MV in vitro studies.