In Vitro Mitral Valve Simulator Mimics Systolic Valvular Function of Chronic Ischemic Mitral Regurgitation Ovine Model

• Type of Material: Article
• Authors: Andrew W. Siefert, Georgia Institute of Technology; Jean Pierre Rabbah, Georgia Institute of Technology; Kevin J. Koomalsingh, University of Pennsylvania; Steven A. Touchton, Georgia Institute of Technology; Neelakantan Saikrishnan, Georgia Institute of Technology; Jeremy R. McGarvey, University of Pennsylvania; Robert C. Gorman, University of Pennsylvania; Joseph H. Gorman, lll, University of Pennsylvania; Ajit Yoganathan, Emory University
• Language: English
• Date: 2013-03-01
• Publisher: Elsevier
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2013 The Society of Thoracic Surgeons.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.athoracsur.2012.11.039
• Title of Journal or Parent Work: Annals of Thoracic Surgery
• ISSN: 0003-4975
• Volume: 95
• Issue: 3
• Start Page: 825
• End Page: 830
• Grant/Funding Information: Robert Gorman and Joseph Gorman were supported by individual Established Investigator Awards from the American Heart Association.; This study was supported by a research grant awarded from the National Institute of Health (R01 HL090661-02); and from the National Heart and Lung Institute (HL063954, HL073021, HL103723, and HL108330).
• Keywords: REPAIR; ANNULAR DILATATION; REVASCULARIZATION; MECHANISMS; Cardiovascular System & Cardiology; ANNULOPLASTY; Cardiac & Cardiovascular Systems; Surgery; CHORDAL FORCE DISTRIBUTION; Science & Technology; GEOMETRY; HEART-FAILURE; Respiratory System; Life Sciences & Biomedicine
• Research Categories: Health Sciences, Medicine and Surgery; Engineering, Biomedical

Abstract

Background: This study was undertaken to evaluate an in vitro mitral valve (MV) simulator's ability to mimic the systolic leaflet coaptation, regurgitation, and leaflet mechanics of a healthy ovine model and an ovine model with chronic ischemic mitral regurgitation (IMR). Methods: Mitral valve size and geometry of both healthy ovine animals and those with chronic IMR were used to recreate systolic MV function in vitro. A2-P2 coaptation length, coaptation depth, tenting area, anterior leaflet strain, and MR were compared between the animal groups and valves simulated in the bench-top model. Results: For the control conditions, no differences were observed between the healthy animals and simulator in coaptation length (p = 0.681), coaptation depth (p = 0.559), tenting area (p = 0.199), and anterior leaflet strain in the radial (p = 0.230) and circumferential (p = 0.364) directions. For the chronic IMR conditions, no differences were observed between the models in coaptation length (p = 0.596), coaptation depth (p = 0.621), tenting area (p = 0.879), and anterior leaflet strain in the radial (p = 0.151) and circumferential (p = 0.586) directions. MR was similar between IMR models, with an asymmetrical jet originating from the tethered A3-P3 leaflets. Conclusions: This study is the first to demonstrate the effectiveness of an in vitro simulator to emulate the systolic valvular function and mechanics of a healthy ovine model and one with chronic IMR. The in vitro IMR model provides the capability to recreate intermediary and exacerbated levels of annular and subvalvular distortion for which IMR repairs can be simulated. This system provides a realistic and controllable test platform for the development and evaluation of current and future IMR repairs.