Gurné O, Chenu P, Polidori C, Louagie Y, Buche M, Haxhe J P, Eucher P, Marchandise B, Schroeder E
Department of Cardiology, Mont-Godinne Hospital, University of Louvain Medical School, Yvoir, Belgium.
J Am Coll Cardiol. 1995 Apr;25(5):1120-8. doi: 10.1016/0735-1097(94)00538-2.
We sought to determine whether internal mammary artery grafts adapt to an increase in myocardial flow demand and whether they restore maximal flow reserve.
Although mammary grafts are now considered the graft of choice for coronary artery bypass surgery, there is still controversy about whether they can provide adequate flow at periods of peak myocardial demand.
Of 28 patients with a mammary graft anastomosed to the left anterior descending coronary artery, 15 were studied early (mean [+/- SD] 8 +/- 2 days) and 13 late (19 +/- 15 months) after operation by quantitative angiography and selective intravascular Doppler analysis at baseline, during pacing and after injection of papaverine and isosorbide dinitrate into the graft. Eleven patients with a normal left anterior descending artery served as control subjects.
At baseline, mean graft diameter (2.39 +/- 0.41 vs. 2.42 +/- 0.45 mm) and bypass flow (38 +/- 22 vs. 30 +/- 12 ml/min) were similar in the early and late postoperative periods. Significant and similar vasodilation was observed in mammary grafts after administration of papaverine (+6 +/- 5% vs. +9 +/- 6%) and nitrates (+14 +/- 7% vs. +16 +/- 9%) both early and late after bypass surgery. Graft diameter increased during pacing late (+6 +/- 3%, p < 0.05) but not early after operation. Bypass flow increased similarly during pacing in both groups, but maximal flow reserve induced by papaverine was significantly lower in mammary grafts studied early (2.70 +/- 0.62) than those studied late (3.66 +/- 0.81, p < 0.01) and in normal coronary arteries (4.05 +/- 0.96, p < 0.001).
An increase in myocardial blood flow induced by pacing resulted in vasodilation of mammary grafts in the late but not in the early postoperative period. Significant vasodilation of mammary grafts after papaverine and isosorbide dinitrate administration was observed both early and late after operation. However, bypass flow reserve after papaverine injection was significantly lower in the early postoperative period but normalized over time. This finding seems unrelated to the conduit; rather, it appears to be related to the periphery and could be the result of injury to the microvasculature during operation.
我们试图确定乳内动脉移植物是否能适应心肌血流需求的增加，以及它们是否能恢复最大血流储备。
尽管乳内动脉移植物现在被认为是冠状动脉搭桥手术的首选移植物，但关于它们在心肌需求高峰期能否提供足够血流仍存在争议。
在28例乳内动脉移植物与左前降支冠状动脉吻合的患者中，15例在术后早期（平均[±标准差]8±2天）接受研究，13例在术后晚期（19±15个月）接受研究。通过定量血管造影和选择性血管内多普勒分析，在基线、起搏期间以及向移植物内注射罂粟碱和硝酸异山梨酯后进行观察。11例左前降支动脉正常的患者作为对照。
在基线时，术后早期和晚期的平均移植物直径（2.39±0.41对2.42±0.45mm）和搭桥血流量（38±22对30±12ml/min）相似。在冠状动脉搭桥手术后早期和晚期，给予罂粟碱（+6±5%对+9±6%）和硝酸盐（+14±7%对+16±9%）后，乳内动脉移植物均观察到显著且相似的血管扩张。起搏晚期移植物直径增加（+6±3%，p<0.05），但术后早期未增加。两组在起搏期间搭桥血流量均有类似增加，但早期研究的乳内动脉移植物中罂粟碱诱导的最大血流储备（2.70±0.62）显著低于晚期研究的移植物（3.66±0.81，p<0.01）和正常冠状动脉（4.05±0.96，p<0.001）。
起搏诱导的心肌血流增加在术后晚期而非早期导致乳内动脉移植物血管扩张。术后早期和晚期给予罂粟碱和硝酸异山梨酯后，乳内动脉移植物均观察到显著的血管扩张。然而，罂粟碱注射后的搭桥血流储备在术后早期显著较低，但随时间推移恢复正常。这一发现似乎与血管移植物无关；相反，它似乎与外周有关，可能是手术期间微血管损伤的结果。
