SUBJECT: M.S. Thesis Presentation
BY: Charles Bloodworth
TIME: Friday, September 22, 2017, 8:30 a.m.
PLACE: Technology Enterprise Park, 104
TITLE: Impact of Simulated MitraClip on Forward Flow Obstruction in the Setting of Mitral Leaflet Tethering
COMMITTEE: Dr. Ajit Yoganathan, PhD, Chair (BME)
Dr. Rudolph Gleason, PhD (ME)
Dr. Vasilis Babaliaros, MD (Emory School of Medicine)


The catheter-based MitraClip device (Abbott Vascular, Santa Clara, CA) is currently the only widely-used and FDA approved endovascular mitral repair device, with over 35,000 patients treated worldwide to-date. MitraClip works by clipping the mitral leaflets together at the site of mitral regurgitation (MR). This closes the regurgitant orifice, while still allowing the leaflets to open to either side of the device, thereby creating a “double orifice”. In many cases, multiple MitraClip devices are used to treat MR, though placement of additional devices can further reduce mitral valve area and increase mean mitral valve gradient, leading to mitral stenosis (MS), or obstruction of forward flow through the MV. In functional MR (FMR) in particular, MS severity after MitraClip may be further exacerbated by diastolic restriction of the anterior mitral leaflet (AML), which is caused by severe dilatation of the left ventricle and papillary muscle displacement. However, limited data on the effect of AML tethering on MS severity after MitraClip exists.

The purpose of this study is to quantify MS severity under different levels of AML tethering, and with simulated placement of MitraClip in different locations. In the first specific aim of this study, an in vitro model capable of simulating MV function and leaflet tethering on excised ovine MV samples was developed, along with custom-designed and machined MitraClip prototypes. In the second specific aim, these tools were used to evaluate the forward flow performance of the MitraClip prototype devices in the setting of mitral leaflet tethering. This first-of-its-kind study will provide valuable information on MitraClip performance, and aid cardiologists in determining the suitability of different MitraClip treatments for the large population of FMR patients.