Phd Proposal by Dongyang Xu

Dongyang Xu

BME PhD Proposal Presentation 


Date: June 4th, 2019

Time: 2:30 pm - 4:30 pm

Location: Technology Enterprise Park (T3 labs), large conference room


Committee members:

Internal Committee Members:

  1. Murali Padala, PhD
  2. Wei Sun, PhD
  3. John Oshinski, PhD

External Committee Members

  1. Robert Guyton, MD (Emory/ Dept. of Surgery)
  2. Pavan Atluri, MD (Penn/Dept. of Surgery)
  3. Sakya Tripathy, PhD (Edwards Lifescience)


The Impact of Undersizing Mitral Annuloplasty on Mitral Valve Biomechanics in Functional Mitral Regurgitation


Functional mitral regurgitation (FMR) is a common valvular lesion in patients surviving ischemic cardiomyopathy. It accelerates left ventricular (LV) failure, worsens prognosis, and doubles mortality. Repair of FMR using undersizing mitral annuloplasty (UMA) is the current gold standard. Such titanium-based D-shaped ring structure, while effective in eliminating FMR acutely, can impose abnormal biomechanical loading on the mitral valve (MV) and potentially lead to FMR recurrence. In my doctoral thesis work, I propose to conduct quantitative biomechanical studies on the effects of UMA on mitral valve mechanics, as a function of the percentage of annular undersizing. Three aims are proposed: (aim 1) design an adjustable undersizing mitral annuloplasty ring (A-UMA) that enables annular undersizing over a large range, and validate its shape and mechanics against commercial static rings of different sizes; (aim 2) Quantify post-UMA changes in MV geometry, leaflet strains and chordal forces in a percent downsizing dependent manner in an ex-vivo FMR model; (aim 3) Investigate the interaction between post-UMA mitral valve and the LA/LV dynamics in a swine model of IMR. Data from these three aims will provide a definitive dataset about MV mechanical changes after UMA and help defining an optimal surgical intervention for FMR patients.


Event Details


  • Tuesday, June 4, 2019
    2:30 pm - 4:30 pm
Location: Technology Enterprise Park (T3 labs), large conference room