van Son J A, Smedts F, Vincent J G, van Lier H J, Kubat K
Department of Thoracic and Cardiac Surgery, Academic Hospital Nijmegen, The Netherlands.
J Thorac Cardiovasc Surg. 1990 Apr;99(4):703-7.
Comparison was made between the morphologic condition of the left anterior descending artery and four arterial conduits: the internal mammary, right gastroepiploic, inferior epigastric, and radial arteries, harvested from 17 patients (aged 15 to 85 years, mean 64 years) who had died of nonvascular diseases. Proximal, mid, and distal segments were examined microscopically. The internal mammary artery was elastic, but the others were muscular. In all four conduits, atherosclerosis was absent to mild, the internal elastic lamina showed only minimal defects, and the vasa vasorum were confined to the adventitia. In all cases the left anterior descending artery showed mild to severe atherosclerosis and substantial defects in the internal elastic lamina with penetration of the vasa vasorum into the media and intima. Comparison of the mean distance (+/- standard deviation) from the lumen to the outermost portion of the media for the left anterior descending artery (320 +/- 63 microns) with the four conduits gave comparable values for the internal mammary artery (350 +/- 92 microns); p = not significant) and the right gastroepiploic artery (291 +/- 109 microns; p = not significant), versus 529 +/- 52 microns; p less than 0.002) for the radial artery and 249 microns (+/- 87 microns) (p less than 0.04) for the inferior epigastric artery (Kruskal-Wallis and Mann-Whitney U tests). The relatively scanty presence of smooth muscle cells in the thin-walled media of the internal mammary artery combined with a well-formed internal elastic lamina, even at advanced age, may be an important cause for its low susceptibility to atherosclerosis and a major determinant in its superior long-term patency as a coronary artery bypass graft. This finding emphasizes the justification of continued use of the ideally matching internal mammary artery, either as in situ or free graft, in coronary artery bypass grafting. In contrast to the thick-walled radial artery, which may be relatively prone to ischemia, an acceptable long-term patency of the inferior epigastric artery and right gastroepiploic artery, if harvested as pedicled grafts, is anticipated.
对17例死于非血管疾病的患者（年龄15至85岁，平均64岁）的左前降支动脉与四条动脉管道（胸廓内动脉、右胃网膜动脉、腹壁下动脉和桡动脉）的形态学状况进行了比较。对近端、中段和远端节段进行了显微镜检查。胸廓内动脉为弹性动脉，而其他动脉为肌性动脉。在所有四条管道中，动脉粥样硬化均不存在或为轻度，内弹性膜仅显示微小缺损，血管滋养管局限于外膜。在所有病例中，左前降支动脉均显示轻度至重度动脉粥样硬化，内弹性膜存在大量缺损，血管滋养管穿透至中膜和内膜。将左前降支动脉从管腔到中膜最外层的平均距离（±标准差）（320±63微米）与四条管道进行比较，胸廓内动脉（350±92微米；p=无显著性差异）和右胃网膜动脉（291±109微米；p=无显著性差异）的值与之相当，而桡动脉为529±52微米（p<0.002），腹壁下动脉为249微米（±87微米）（p<0.04）（Kruskal-Wallis和Mann-Whitney U检验）。即使在高龄时，胸廓内动脉薄壁中膜中平滑肌细胞相对较少，加上内弹性膜发育良好，这可能是其对动脉粥样硬化敏感性低的重要原因，也是其作为冠状动脉旁路移植长期通畅率高的主要决定因素。这一发现强调了在冠状动脉旁路移植术中继续使用理想匹配的胸廓内动脉（无论是原位还是游离移植）的合理性。与可能相对易发生缺血的厚壁桡动脉不同，如果将腹壁下动脉和右胃网膜动脉作为带蒂移植物采集，预计其长期通畅率是可以接受的。
