Share this page on LinkedIn
Share This Page on Google+
Share This Page on Twitter
tell someone about this page print this page
You are here: Contents > 2014 > Volume 23 Number 1 January 2014 > MITRAL VALVE DISEASE > Impact of Mitral Valve Geometry on Hemodynamic Efficacy of Surgical Repair in Secondary Mitral Regurgitation

Impact of Mitral Valve Geometry on Hemodynamic Efficacy of Surgical Repair in Secondary Mitral Regurgitation

Muralidhar Padala1, Lazarina I. Gyoneva2, Vinod H. Thourani1, Ajit P. Yoganathan2

1Structural Heart Disease Research & Innovation Laboratory, Division of Cardiothoracic Surgery, Emory University, Atlanta, 2Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, USA

Background and aim of the study: Mitral valve geometry is significantly altered secondary to left ventricular remodelling in non-ischemic and ischemic dilated cardiomyopathies. Since the extent of remodelling and asymmetry of dilatation of the ventricle differ significantly between individual patients, the valve geometry and tethering also differ. The study aim was to determine if mitral valve geometry has an impact on the efficacy of surgical repairs to eliminate regurgitation and restore valve closure in a validated experimental model.

Methods: Porcine mitral valves (n =8) were studied in a pulsatile heart simulator, in which the mitral valve geometry can be precisely altered and controlled throughout the experiment. Baseline hemodynamics for each valve were measured (Control), and the valves were tethered in two distinct ways: annular dilatation with 7 mm apical papillary muscle (PM) displacement (Tether 1, symmetric), and annular dilatation with 7 mm apical, 7 mm posterior and 7 mm lateral PM displacement (Tether 2, asymmetric). Mitral annuloplasty was performed on each valve (Annular Repair), succeeded by anterior leaflet secondary chordal cutting (Sub-annular Repair). The efficacy of each repair in

the setting of a given valve geometry was quantified by measuring the changes in mitral regurgitation (MR), leaflet coaptation length, tethering height and area.

Results: At baseline, none of the valves was regurgitant. Significant leaflet tethering was measured in Tether 2 over Tether 1, but both groups were significantly higher compared to baseline (60.9 ± 31 mm2 for Control versus 129.7 ± 28.4 mm2 for Tether 1 versus 186.4 ± 36.3 mm2 for Tether 2). Consequently, the MR fraction was higher in Tether 2 group (23.0 ± 5.7%) than in Tether 1 (10.5 ± 5.5%). Mitral annuloplasty reduced MR in both groups, but remnant regurgitation after the repair was higher in Tether 2. After chordal cutting a similar trend was observed with trace regurgitation in Tether 1 group at 3.6 ± 2.8%, in comparison to 18.6 ± 4.2% in the Tether 2 group.

Conclusion: In this experimental model, the tethering geometry of the mitral valve impacts the valve hemodynamics after annuloplasty and chordal cutting. The quantitative assessment of valve geometry may help in tailoring a repair to the specific tethering pattern.

The Journal of Heart Valve Disease 2014;23:79-87

Impact of Mitral Valve Geometry on Hemodynamic Efficacy of Surgical Repair in Secondary Mitral Regurgitation

Click the above hyperlink to view the article, right click (Ctrl click on a Mac) to open in a new browser window or tab.

Purchase this Article

Please click the button below to purchase this article. Single article purchases are provided at $50.00 per article. Upon clicking the button below, single article user account subscription details are requested and, upon successful payment, a single article user account is created. Single articles are availble in your account for seven days after purchase.