title: Mitral valve repair: an in-vitro comparison of the effect of surgical repair on the pressure required to cause mitral valve regurgitation.
abstract: OBJECTIVE
  The study aim was to compare mitral valve repair techniques in vitro. Rupture or elongation of the mitral valve chordae tendineae is a known cause of mitral regurgitation, and can be corrected by edge-to-edge repair, chordal replacement, or chordal transposition.
  
  
  METHODS
  A test apparatus was used to apply pressure to porcine mitral valves. Mitral valve specimens were tested intact (n = 50), after they had been experimentally damaged, and after repair. Each test was repeated ten times. Experimental damage consisted of severing either the anterior leaflet strut, and attached marginal chordae (n = 30) or posterior leaflet chordae (n = 20). Valves with damaged anterior leaflets were repaired by either: (i) edge-to-edge repair; (ii) chordal replacement; or (iii) chordal transposition. Valves with damaged posterior leaflets were repaired by the first two techniques. Each repair method was repeated on ten specimens.
  
  
  RESULTS
  Mitral valves repaired using the edge-to-edge repair (p = 0.002) and chordal replacement (p = 0.038), after rupture to anterior leaflet chordae, recovered significantly better than specimens repaired by chordal transposition. There was no statistical difference in recovery between edge-to-edge repair and chordal replacement (p > 0.05). There was no statistical difference (p > 0.05) in the recovery of the pressure withstood by valves repaired by edge-to-edge repair and chordal replacement, after rupture of posterior leaflet chordae.
  
  
  CONCLUSIONS
  These results showed that edge-to-edge repair and chordal replacement are well suited for the repair of both the anterior and posterior leaflets.
authors.affiliation: Department of Mechanical and Manufacturing Engineering, School of Engineering, University of Birmingham, Birmingham, Edgbaston, UK. d.m.espino@bham.ac.uk
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Espino
authors.forename: David W L
authors.initials: DW
authors.lastname: Hukins
authors.forename: Duncan E T
authors.initials: DE
authors.lastname: Shepherd
authors.forename: Keith G
authors.initials: KG
authors.lastname: Buchan
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D006801:Humans; D066298:In Vitro Techniques; D008943:Mitral Valve / Q000473:pathology / Q000503:physiopathology; D008944:Mitral Valve Insufficiency / Q000503:physiopathology / Q000601:surgery*; D013552:Swine