Comparison of Artificial Neochordae and Native Chordal Transfer in the Repair of a Flail Posterior Mitral Leaflet: An Experimental Study

• Type of Material: Article
• Authors: Sai Muralidhar Padala, Emory University; Benedicte Cardinau, Georgia Institute of Technology; Lazarina I. Gyoneva, Georgia Institute of Technology; Vinod Thourani, Emory University; Ajit Yoganathan, Emory University
• Language: English
• Date: 2013-02
• Publisher: Elsevier
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2012 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.
• License: Creative Commons Attribution-NonCommerical-NoDerivs 3.0 Unported
• Final Published Version (URL): http://dx.doi.org/10.1016/j.athoracsur.2012.09.055
• Title of Journal or Parent Work: Annals of Thoracic Surgery
• ISSN: 0003-4975
• Volume: 95
• Issue: 2
• Start Page: 629
• End Page: 633
• Grant/Funding Information: M.P was supported by an American Heart Association Pre-doctoral Fellowship during the study, and the study was partially supported by a National Institute of Health grant to A.P.Y (R01-HL090661).
• Keywords: Mitral valve repair; Valve surgery; Neochordae; Cardiac surgery; Secondary chordae; Mitral valve hemodynamics; Chordal transfer; Posterior leaflet flail; Primary chordae
• Research Categories: Health Sciences, Medicine and Surgery

Abstract

BACKGROUND Surgical reconstruction of a flail posterior leaflet is a routine mitral valve repair, the techniques for which have evolved from leaflet resection to leaflet preservation. Artificial ePTFE neochordae are frequently used to stabilize the flail leaflet, and seldom translocation of the native secondary chordae of the valve to the leaflet free edge is used. In this study, we sought to investigate the efficacy of the two techniques to correct posterior leaflet prolapse and reduce mitral regurgitation, and quantify the acute post-repair leaflet kinematics. METHODS Adult porcine mitral valves (N =7) were studied in a pulsatile left heart experimental model in which isolated P2 flail was mimicked by marginal chordal transection. Baseline conditions were established in each valve under normal conditions (control), and followed by induction of isolated P2 flail by transecting the two marginal chordae on the posterior leaflet free edge (disease). The flail posterior leaflet was reconstructed using artificial neochordae (repair 1) and then native chordal translocation (repair 2). Reduction in leaflet flail, changes in mitral regurgitation fraction, leaflet coaptation length, and posterior leaflet mobility were measured using B-mode echocardiography or color doppler. RESULTS At baseline, all the valves were competent with no mitral regurgitation. After transection of the marginal chordae on the posterior leaflet, isolated P2 flail was evident with 13.7±13% regurgitation. Reconstruction with artificial neochordae eliminated leaflet flail and reduced mitral regurgitation to 3.2± 2.8%, and with chordal translocation leaflet flail was corrected and mitral regurgitation was measured at 2.3±2.6%. Using either repair techniques, leaflet coaptation and mobility of the repaired leaflets were adequate and comparable to the baseline measurements. CONCLUSIONS Comparable reduction leaflet flail and regurgitation, and restoration of physiological leaflet coaptation with the two techniques indicates that under acute conditions, use of artificial neochordae or native chordal translocations have similar benefits.