Abstract
During a total of 518 coronary bypass surgery cases, we encountered 144 incidence (28%) of muscle briges overriding the coronary artery. Of these 144 cases, we found 111 in the left anterior descending coronary artery (77%). As opposed to the control group, the muscle bridge group was found 32% more in the female-to-male ratio, which suggests atherosclerotic progressive factors for female patients. During coronary bypass grafting, we preferred to excise muscle bridges and select this as the site of graft-to-coronary bypass anastomosis, due to the absence of atherosclerosis within this segment. By constructing a mock circuit, which contains a muscle bridge that was actuated by compressing a silastic tube periodically, we observed movement of microspheres using a microscope and a high-speed video system. We suspected, based on the movement of microspheres, the possibility of intimal cell damage. We concluded that muscle bridges are one of the contributing factors of atherosclerotic progression, particullarly in the region of the left anterior descending coronary artery.
