Boston - American Association for Thoracic Surgery

AMERICAN ASSOCIATION FOR THORACIC SURGERYF4. 3D Geometry of the Mitral Valve Determines the Success ofSecondary Chordal Cutting in Alleviating Ischemic MitralRegurgitationMuralidhar Padala, 1 Katherine L. Bell, 1 Vinod H. Thourani, 3 David H. Adams, 2*†Ajit P. Yoganathan 11. Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA; 2.Mt. Sinai Hospital, New York, NY, USA; 3. Emory University, Atlanta, GA, USAInvited Discussant: Gus J. VlahakesOBJECTIVE: Mitral annuloplasty often fails in patients with dilated left ventriclesdue to ischemic heart disease or cardiomyopathies, resulting in recurrence ofmitral regurgitation (MR). Sub-valvular repair using secondary chordal cutting(CT-cut) is proposed as a solution to prevent recurrent MR by relieving leaflet tethering.However, current clinical literature is divided on the efficacy of this techniquewith some studies supporting its efficacy while others challenging it. In thisstudy, we sought to investigate if the 3D geometry of the mitral valve (ie, spatiallocation of the papillary muscles in the ventricle, and extent of leaflet tethering)impacts the outcomes of the chordal cutting technique.METHODS: Eight porcine mitral valves (N = 8) of sizes 28 were studied in an invitropulsatile left heart simulator at 120 mm Hg peak transmitral pressure, 5 L/mincardiac output at 70 bpm. Each valve was first tested with its physiological geometryto obtain the baseline conditions. MR was induced by dilating the annulus (to size34) and selectively displacing the PMs first by 10 mm apically only, followed by 10mm apically, laterally & posteriorly. MR was repaired in both cases by implantingan annuloplasty ring (size 28) first and then by transecting the secondary chordaeon the anterior leaflet. At each step, MR volume (ml/beat), and tenting area (mm2)were measured and compared to the baseline.TUESDAYMorningFigure 1A: depicts the MR volume before and after chordal cutting for the twoPM positions; Figure 1B: depicts the reduction in tenting area with chordal cuttingfor the two PM positions* AATS Member† Alton Ochsner Research Scholarship 1992127