Hoover E L, Pett S B, Eldor A, Alonso D, Subramanian V A, Weksler B, Gay W A
Circulation. 1981 Aug;64(2 Pt 2):II96-100.
Efforts to improve myocardial preservation during aortocoronary bypass procedures have led to the perfusion of saphenous vein segments with potassium cardioplegic (KCP) solutions after completion of the distal anastomosis. Recent reports show that the procurement of veins leads to varying degrees of damage, particularly to the endothelial surface, as a result of the dissection itself, the hydrostatic pressure required to distend the veins in obtaining hemostasis and the composition of the solutions used to irrigate the harvested segments. The biologic activity of arterialized vein segments is largely unknown. We tested the hypothesis that the degree of venous injury inherent in vein harvesting may be compounded by perfusion with a potassium-rich solution, a known vascular irritant. The external jugular vein was removed from 18 dogs. Half of the vein was perfused with 300 ml of a KCP solution at 4 degrees C (40 mEq/l KCl, 10 ml sodium bicarbonate, pH 7.6, osmolarity 340 mosmol) and the other half with lactated Ringer's solution (LR). The treated vein was reversed and interposed into the excluded internal carotid circulation. A sham dissection was done on the opposite jugular vein. The veins were harvested after 6 weeks and assayed for spontaneous and arachidonate-stimulated (AS) prostacyclin activity as well as light microscopic analysis of morphologic changes. Spontaneous and AS production of prostacyclin did not differ significantly in the sham, LR and KCP groups: 1539 +/- 709 and 4166 +/- 1802, 1569 +/- 763 and 3767 +/- 2706, 1860 +/- 1233 and 3947 +/- 3347 pg/ml). Light microscopic analysis revealed an intense adventitial fibrotic reaction in the KCP group and the appearance of fibroblast-like cells in the outer layer of the vein wall. The intima was intact in all three groups. We conclude that intimal damage sustained during harvesting is repaired within 6 weeks, and there is no impairment to surface production of prostacyclin. The intense adventitial fibrotic reaction observed in the KCP-treated group has not been previously reported, and its significance remains unexplained.
在主动脉冠状动脉搭桥手术中，为改善心肌保护所做的努力促使在完成远端吻合术后用钾停搏液（KCP）灌注大隐静脉段。最近的报告显示，由于解剖本身、在获得止血过程中扩张静脉所需的静水压力以及用于冲洗采集段的溶液成分，静脉的获取会导致不同程度的损伤，尤其是内皮表面的损伤。动脉化静脉段的生物活性在很大程度上尚不清楚。我们检验了这样一个假设，即静脉采集所固有的静脉损伤程度可能会因用富含钾的溶液（一种已知的血管刺激物）灌注而加剧。从18只狗身上取下颈外静脉。静脉的一半用300毫升4℃的KCP溶液（40毫当量/升氯化钾、10毫升碳酸氢钠、pH值7.6、渗透压340毫摩尔）灌注，另一半用乳酸林格氏液（LR）灌注。将处理过的静脉翻转并置于被排除的颈内循环中。对另一侧颈静脉进行假解剖。6周后采集静脉，检测其自发和花生四烯酸刺激（AS）的前列环素活性以及形态学变化的光镜分析。假手术组、LR组和KCP组中前列环素的自发和AS产生量没有显著差异：分别为1539±709和4166±1802、1569±763和3767±2706、1860±1233和3947±3347皮克/毫升）。光镜分析显示KCP组有强烈的外膜纤维化反应，且静脉壁外层出现成纤维细胞样细胞。三组的内膜均完整。我们得出结论，采集过程中遭受的内膜损伤在6周内得以修复，且前列环素的表面产生没有受损。在KCP处理组中观察到的强烈外膜纤维化反应此前未见报道，其意义仍无法解释。
