Mitral valve repair: an in-vitro comparison of the effect of surgical repair on the pressure required to cause mitral valve regurgitation.
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.
Espino
Daniel M
DM
Department of Mechanical and Manufacturing Engineering, School of Engineering, University of Birmingham, Birmingham, Edgbaston, UK. d.m.espino@bham.ac.uk
Hukins
David W L
DW
Shepherd
Duncan E T
DE
Buchan
Keith G
KG
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