Mitral valve hemodynamics after repair of acute posterior leaflet prolapse: Quadrangular resection versus triangular resection versus neochordoplasty

• Type of Material: Article
• Authors: Muralidhar Padala, Emory University; Scott N. Powell, Georgia Institute of Technology; Laura R. Croft, Georgia Institute of Technology; Vinod Thourani, Emory University; Ajit Yoganathan, Emory University; David H. Adams, Mt Sinai School of Medicine
• Language: English
• Date: 2009-08-01
• Publisher: Elsevier
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2009 The American Association for Thoracic Surgery.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.jtcvs.2009.01.031
• Title of Journal or Parent Work: Journal of Thoracic and Cardiovascular Surgery
• ISSN: 0022-5223
• Volume: 138
• Issue: 2
• Start Page: 309
• End Page: 315
• Keywords: DURABILITY; Cardiovascular System & Cardiology; Science & Technology; Life Sciences & Biomedicine; Surgery; Respiratory System; DEGENERATIVE DISEASE; INSUFFICIENCY; Cardiac & Cardiovascular Systems; REGURGITATION
• Research Categories: Health Sciences, Medicine and Surgery; Engineering, Biomedical

Abstract

Objective: Leaflet prolapse resulting from acute chordal rupture is one presentation of fibroelastic deficiency that is associated with minimal leaflet changes in the prolapsing segment. Minimizing resection and preserving leaflet tissue may be an optimal surgical strategy. We examined the importance of the leaflet preservation concept by comparing resective and nonresective surgical procedures in practice today. Methods: Eight porcine mitral valves were evaluated in an in vitro heart simulator before surgical manipulation. Mitral regurgitation was created in these valves by transecting the posterior marginal chordae resulting in severe P2 prolapse. After confirmation of mitral regurgiation via regurgitant flow measurement (mL/beat), regurgitation was corrected by three repairs: neochordoplasty with polytetrafluoroethylene sutures (Gore-Tex; W. L. Gore & Associates, Inc, Flagstaff, Ariz), triangular resection, and quadrangular resection with annular compression. Postrepair valve hemodynamics were quantified under pulsatile conditions of 120 mm Hg peak transmitral pressure and 5 L/min cardiac output at 70 beats/min. Furthermore, hemodynamic, geometric, and echocardiographic indices were measured. Results: Transecting the marginal chordae resulted in severe P2 prolapse and significant mitral regurgiation (19.3 ± 4.3 mL/beat). Regurgitant volume was significantly reduced after any of the three surgical approaches (quadrangular, 4.38 ± 1.6 mL/beat; triangular, 2.56 ± 1.0 mL/beat; neochordal, 2.86 ± 1.24 mL/beat). In comparison with the baseline normal valves, leaflet coaptation length and posterior leaflet mobility were significantly reduced in the quadrangular resection group, whereas they were partially restored in the triangular resection and fully preserved in the neochordoplasty group. Conclusions: Although the three repair procedures are hemodynamically comparable, valve function and leaflet kinematics were significantly better after a nonresection or limited resective correction of leaflet prolapse in this experimental model of acute chordal rupture with otherwise normal leaflet geometry.