Abstract 12762: Morphological Change of Mitral Valve Complex During Off-pump Coronary Artery Bypass Surgery by Three-dimensional Echocardiography in Porcine Model
Backgrounds: It is considered that morphological changes of mitral valve complex and worsening of mitral regurgitation (MR) cause the hemodynamic deterioration during off-pump coronary artery bypass grafting (OPCAB) in patients with ischemic hear disease (IHD). However, it remains unclear how morphological changes of mitral valve complex are observed by dislocation of the heart during OPCABG. The aim of this study is to evaluate the morphological changes of the mitral valve complex in beating dislocated heart by three-dimensional (3D) echocardiography in porcine OPCABG models.
Methods: In 9 healthy porcine with general anesthesia and median sternotomy, we positioned the beating heart using Starfish heart positioner® and Octopus 2® (Medtronic) as OPCAB model. In 4 positions for CABG, i.e., control, LAD-, RCA-, and LCX- positions, 3D full volume images were acquired (iE33® and X5-1®, Phillips Healthcare) to assess mitral valve complex. In addition, hemodynamic parameters were monitored during all procedure. We assessed the morphological changes of the mitral valve complex in 4 positions using by Real-view® (YD Co.) and Cardio-view® (TomtTec).
Results: Systolic arterial pressure (mmHg) was significantly lower in LCX position than in control position (LCX 48.9±2.5 vs control 69.8±2.7, P≤0.001).There were no significant differences in the mitral annulus circumference diameter and mitral annular diameters of anterior-posterior and medial-lateral in each position compared to control. On the other hand, the maximum tenting height (mm) was significantly increased in LCX position (control 2.9±0.5, LAD 2.7± 0.3, RCA 3.7± 0.3, LCX 4.1± 0.3, P≤0.01), and the mean tenting length (mm) was significantly increased in RCA and LCX positions (control 0.7±0.4, LAD 0.5±0.3, RCA 1.3±0.2, LCX 1.5±0.2, P≤0.001). The tenting volume (cm3) was significantly larger in LCX position (control 0.7±0.1, LAD 0.6±0.1, RCA 0.8±0.1, LCX 1.0±0.1, P≤0.05).
Conclusions: In the dislocated and rotated position of the heart, especially in LCX position, the tethering of the mitral valve leaflet was increased. This study suggests that mitral valve tethering cause the exacerbation of hemodynamics during OPCAB, and it may cause the worsening of ischemic MR in IHD patients.
- © 2013 by American Heart Association, Inc.