title: Peak mechanical loads induced in the in vitro edge-to-edge repair of posterior leaflet flail.
abstract: BACKGROUND
  Percutaneous edge-to-edge mitral valve (MV) repair is a potential therapeutic option for patients presenting with mitral regurgitation, who may not be suitable for surgery. We characterized the edge-to-edge repair forces in a posterior leaflet flail MV model to identify potential modes of mechanical failure.
  
  
  METHODS
  Porcine MVs were evaluated in two different sizes (Physio II 32 and 40) in a left-side heart simulator under physiologic hemodynamic conditions. Edge-to-edge repair was simulated by suturing miniature force transducers near the free edge of the anterior and posterior leaflets, on the ventricular side, resulting in a double orifice MV. Posterior leaflet flail was created by selective chordal cutting.
  
  
  RESULTS
  Chordal cutting resulted in posterior leaflet flail and mitral regurgitation; all valves coapted normally before chordal cutting. Peak systolic control forces (size 32, 0.098 ± 0.058 N; size 40, 0.236 ± 0.149 N) were not significantly different from systolic flail forces (size 32, 0.136 ± 0.107 N; size 40, 0.220 ± 0.128 N) for either MV size. No correlation was observed between force magnitude and flail height or width. Peak systolic force was greater (p = 0.08) for the larger MVs (size 40 compared with size 32). Finally, peak diastolic force was significantly smaller (p = 0.04) than peak systolic force regardless of valve size.
  
  
  CONCLUSIONS
  For the first time, forces imparted on an edge-to-edge MV repair were quantified for a posterior leaflet flail model. Force magnitude was not significantly altered with flail compared with control; it was greatest during peak systole and increased with valve size.
authors: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA.
authors: Jean-Pierre M
authors: JP
authors: Rabbah
authors: Andrew W
authors: AW
authors: Siefert
authors: Erin M
authors: EM
authors: Spinner
authors: Neelakantan
authors: N
authors: Saikrishnan
authors: Ajit P
authors: AP
authors: Yoganathan
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D008944:Mitral Valve Insufficiency / Q000503:physiopathology* / Q000601:surgery; D013552:Swine; D014160:Transducers, Pressure