Hanet C, Semaan C, Khoury G, Dion R, Robert A
Division of Cardiology, University of Louvain, Brussels, Belgium.
Circulation. 1994 Nov;90(5 Pt 2):II155-9.
The gastroepiploic artery is increasingly used as an alternative arterial coronary bypass conduit. In vitro studies have reported differences in vasoreactivity among various types of coronary graft conduits, susceptible to influencing the adaptation of myocardial blood flow and long-term patency rate.
To evaluate in vivo the vasoreactivity of gastroepiploic artery grafts implanted long-term, nine angiographically smooth grafts implanted to the distal right or to the left circumflex coronary artery were studied with quantitative angiography 6 to 36 months after surgery. Angiograms were obtained on 35mm cinefilms in basal conditions, after injection of methylergometrine (0.4 mg IV), and after intragraft injection of 1 mg isosorbide dinitrate. In basal conditions, there was no difference in luminal diameter between gastroepiploic and coronary arteries (1.64 +/- 0.32 versus 1.51 +/- 0.31 mm; P = NS). After methylergometrine, a constriction was observed in all gastroepiploic artery grafts (-14 +/- 6% of basal diameter) and in all but one grafted coronary artery (-6 +/- 5%). After isosorbide dinitrate, a dilation was consistently observed in all gastroepiploic artery grafts (+26 +/- 9%) and grafted coronary arteries (+14 +/- 7% of basal). Changes in lumen diameter in response to these constrictor and dilator stimuli, either expressed in absolute values or in percentage of control were significantly greater (P < .001) in gastroepiploic artery grafts than in grafted coronary arteries.
Gastroepiploic artery grafts implanted long-term are more reactive than grafted coronary arteries to ergometrine and nitrates. This response differs from that previously reported of internal mammary artery grafts to the same pharmacological vasoactive stimuli. This suggests that the concept of a more efficient endothelium-dependent control of vasomotor tone contributing to better long-term functional results of internal mammary artery grafts cannot be directly extrapolated to gastroepiploic artery grafts.
胃网膜动脉越来越多地被用作冠状动脉旁路移植的替代动脉管道。体外研究报告了各种类型冠状动脉移植管道之间血管反应性的差异，这可能会影响心肌血流的适应性和长期通畅率。
为了在体内评估长期植入的胃网膜动脉移植物的血管反应性，对9例移植到右冠状动脉远端或左旋支冠状动脉的血管造影显示通畅的移植物进行了研究，在术后6至36个月采用定量血管造影术。在基础状态下、注射甲基麦角新碱（0.4mg静脉注射）后以及在移植物内注射1mg硝酸异山梨酯后，在35mm电影胶片上获取血管造影图像。在基础状态下，胃网膜动脉和冠状动脉的管腔直径无差异（1.64±0.32对1.51±0.31mm；P=无显著性差异）。注射甲基麦角新碱后，所有胃网膜动脉移植物均出现收缩（-14±6%基础直径），除一根移植冠状动脉外，其余所有移植冠状动脉均出现收缩（-6±5%）。注射硝酸异山梨酯后，所有胃网膜动脉移植物均持续出现扩张（+26±9%），移植冠状动脉也出现扩张（+14±7%基础值）。胃网膜动脉移植物对这些收缩剂和扩张剂刺激的管腔直径变化，无论是以绝对值还是以对照百分比表示，均显著大于（P<0.001）移植冠状动脉。
长期植入的胃网膜动脉移植物对麦角新碱和硝酸盐的反应性比移植冠状动脉更强。这种反应与先前报道的乳内动脉移植物对相同药理血管活性刺激的反应不同。这表明，内皮依赖性血管运动张力控制更有效从而有助于乳内动脉移植物获得更好长期功能结果的概念不能直接外推至胃网膜动脉移植物。
