title: Repair of posterior mitral valve prolapse with a novel leaflet plication clip in an animal model.
abstract: OBJECTIVE
  Recently, there has been increased interest in minimally invasive mitral valve prolapse repair techniques; however, these techniques have limitations. A new technique was developed for treating mitral valve prolapse that uses a novel leaflet plication clip to selectively plicate the prolapsed leaflet segment. The clip's efficacy was tested in an animal model.
  
  
  METHODS
  Yorkshire pigs (n = 7) were placed on cardiopulmonary bypass (CPB), and mitral valve prolapse was created by cutting chordae supporting the P2 segment of the posterior leaflet. Animals were weaned off CPB and mitral regurgitation (MR) was assessed echocardiographically. CPB was reinitiated and the plication clip was applied under direct vision to the P2 segment to eliminate the prolapse. The animals survived for 2 hours. Epicardial echocardiography was obtained before and after prolapse creation and 2 hours after clip placement to quantify MR grade and vena contracta area. Posterior leaflet mobility and coaptation height were analyzed before and after clip placement.
  
  
  RESULTS
  There were no cases of clip embolization. Median MR grade increased from trivial (0-1.5) to moderate-severe after MR creation (2.5-4+) (P < .05), and decreased to mild after clip placement (0-3+) (P < .05). Vena contracta area tended to increase after cutting the chordae and decrease after clip placement: 0.08 ± 0.10 cm(2) versus 0.21 ± 0.15 cm(2) versus 0.16 ± 0.16 cm(2) (P = .21). The plication clip did not impair leaflet mobility. Coaptation height was restored to baseline: 0.51 ± 0.07 cm versus 0.44 ± 0.18 cm (P = 1.0).
  
  
  CONCLUSIONS
  The leaflet plication clip can treat mitral valve prolapse in an animal model, restoring coaptation height without affecting leaflet mobility. This approach is a simple technique that may improve the effectiveness of beating-heart and minimally invasive valve surgery.
authors.affiliation: Department of Cardiac Surgery, Boston Children's Hospital, Harvard Medical School, Boston, Mass.
authors.forename: Eric N
authors.initials: EN
authors.lastname: Feins
authors.affiliation: Department of Cardiac Surgery, Boston Children's Hospital, Harvard Medical School, Boston, Mass.
authors.forename: Haruo
authors.initials: H
authors.lastname: Yamauchi
authors.affiliation: Department of Cardiology, Boston Children's Hospital, Harvard Medical School, Boston, Mass.
authors.forename: Gerald R
authors.initials: GR
authors.lastname: Marx
authors.affiliation: Department of Pediatric Cardiology, Kardiozentrum, La Paz, Bolivia.
authors.forename: Franz P
authors.initials: FP
authors.lastname: Freudenthal
authors.affiliation: Department of Cardiac Surgery, Boston Children's Hospital, Harvard Medical School, Boston, Mass.
authors.forename: Hua
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Cardiac Surgery, Boston Children's Hospital, Harvard Medical School, Boston, Mass.
authors.forename: Pedro J
authors.initials: PJ
authors.lastname: Del Nido
authors.affiliation: Department of Cardiac Surgery, Boston Children's Hospital, Harvard Medical School, Boston, Mass. Electronic address: nikolay.vasilyev@childrens.harvard.edu.
authors.forename: Nikolay V
authors.initials: NV
authors.lastname: Vasilyev
mesh_terms: D000818:Animals; D006348:Cardiac Surgical Procedures / Q000009:adverse effects / Q000295:instrumentation*; D002315:Cardiopulmonary Bypass; D004195:Disease Models, Animal; D018618:Echocardiography, Doppler, Color; D004867:Equipment Design; D008422:Materials Testing; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D008945:Mitral Valve Prolapse / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D053831:Surgical Fixation Devices; D013552:Swine; D013997:Time Factors
keywords: 28; 35.4.1; ANOVA; CH; CPB; IACUC; ICC; Institutional Animal Care and Use Committee; LPC; MVP; VCA; analysis of variance; cardiopulmonary bypass; coaptation height; intraclass correlation coefficients; leaflet plication clip; mitral valve prolapse; vena contract area