Cardiovascular Fluid Mechanics Laboratory

Mitral Valve Annuloplasty

Annuloplasty is a common surgical treatment for ischemic mitral regurgitation (IMR). While mostly successful, unintended failures from surgical technique result in suture dehiscence in the early post-operative period, underlying 13-42% of all reoperations. The goal of this study is to investigate ring designs that restore normal valve geometry and reduce ring suture forces to eventually reduce dehiscence likelihood. Rings are implanted in animal models instrumented with in house manufactured custom force transducers to measure beating heart forces.

Selected publications

  1. Ncho BE, Pierce EL, Bloodworth CH 4th, et al. Optimized mitral annuloplasty ring design reduces loading in the posterior annulus. The Journal of Thoracic and Cardiovascular Surgery. 2020 May;159(5):1766-1774.e2. DOI: 10.1016/j.jtcvs.2019.05.04
  2. Pierce, E. L., Bloodworth, C. H., 4th, Siefert, A. W., Easley, T. F., Takayama, T., Kawamura, T., Gorman, R. C., Gorman, J. H., 3rd, & Yoganathan, A. P. (2018). Mitral annuloplasty ring suture forces: Impact of surgeon, ring, and use conditions. The Journal of thoracic and cardiovascular surgery, 155(1), 131–139.e3. https://doi.org/10.1016/j.jtcvs.2017.06.036
  3. Pierce, E. L., Siefert, A. W., Paul, D. M., Wells, S. K., Bloodworth, C. H., 4th, Takebayashi, S., Aoki, C., Jensen, M. O., Gillespie, M. J., Gorman, R. C., Gorman, J. H., 3rd, & Yoganathan, A. P. (2016). How Local Annular Force and Collagen Density Govern Mitral Annuloplasty Ring Dehiscence Risk. The Annals of thoracic surgery, 102(2), 518–526. https://doi.org/10.1016/j.athoracsur.2016.01.107

MitraClip Edge to Edge Repair

Transcatheter edge-to-edge repair is suitable to treat mitral regurgitation (MR) for high-risk patients as a noninvasive alternative to surgery. During the procedure, more than one device may be used to sufficiently decrease regurgitation. Although the primary goal is to reduce MR, elevation of mitral valve pressure gradient (MVG) and resulting mitral stenosis (MS) remains a concern, as iatrogenic MS leads to worse outcomes than residual regurgitation. The objective of this study was to assess regurgitation and MVG using porcine mitral valves at various severities of degenerative MR, treated with 0, 1, and 2 MitraClip NT devices. In this controlled study, there was no concern for elevated MVG with use of two MitraClips compared to one. Additional studies are underway to further assess the pressure gradient with the double orifice.

Selected Publication:

Gooden, S., Hatoum, H., Boudoulas, K., Dasi, L. “Multiple MitraClips: The Balancing Act between Pressure Gradient and Regurgitation.” JTCVS. https://doi.org/10.1016/j.jtcvs.2020.05.049.