| Objective: Cardiovascular disease is one of the major diseases for threating peoples’ health, and coronary artery disease is the most commo n disease of them. The main methods for treating coronary artery diseas es are including coronary artery bypass graft(CABG), percutaneous transl uminal coronary angioplasty, drugs treatment and so on. At present, coro nary artery bypass grafting is one of the most effective ways for treatin g coronary artery disease. The main source of vessel grafts is internal mammary artery(IMA), radial artery, great saphenous vein(GSV) and s o on. Arterial grafts are rarely atherosclerosis, and it has been widely a pplied in clinical because of the higher long-term patency rate. However,there are some shortcomings about the artery transplantation operation, such as higher requirements for surgeon’s skills, higher bleeding risks, h igher required operators, fewer resources for harvesting and so on. Com pared with artery transplantation operation, the source of GSV is adequa te and easy to harvest.So autologous GSV is still one of the most co mmonly used materials in CABG at present. But many aspects maybe c ause GSV vascular injured during CABG operation, such as the poor va scular anatomy, unsuitable surgery technologies to take the vein away fr om the body during harvesting, vein endothelial damaging in physiologic al condition before vascular anastomosis, and the endothelial damaging i n the process of vein bypass graft arterialized, etc. These factors affect the vein graft patency rate, and the vein graft patency rate is only abou t 40-50% after 10 years of surgery. So, how to improve the long-term patency rate of GSV grafts and reduce restenosis graft has become a ho t spot of cardiovascular surgical research.Usually the vein graft needs washing by venous protective liquid, expansion and soaked preservation after it is harvest. At present, heparin and papaverine saltwater protective solution are widely used in clinic, which can expand the GSV and restrain contracture, but couldn’t protect vascular endothelial cells enough. However, the perfect venous protection liquid should expand the vein and protect formation of structure and function of vascular endothelial cell to prevent restenosis and improve primary patency. This experiment studied the protective effect of nicorandil and other clinic common protective solutions on rabbits’ jugular vein graft, in order to find a better vascular graft protective solution for clinic CABG.Methods: This experiment simulated the process of CABG surgery of patients with coronary artery disease, and established the experimental animal model of rabbit ipsilateral common carotid artery external jugular vein bypass. Thirty healthy New Zealand white rabbits provided by the laboratory animal center of Hebei medical university were randomly divided into three groups(A, B, C). Intraoperative three kinds of different protective liquids were applied: heparin protective fluid, papaverine protective fluid, nicorandil protective fluid, which was used on the preservation of vein grafts in vitro. The vein grafts were stored into the three different protective solutions half an hour at room temperature(20℃). Parts of the vein were taken for preoperative morphological observation, and ELISA method was used to measure endothelin content(ET-1) of preserving fluids. The other part selection of jugular veins were taken for end-to-side anastomosis with the common carotid artery, and the central part of vein grafts was taken after postoperative 2 weeks for observation. The morphological change of bypass grafts was observed using light microscope, and microscope was be used to examined hyperplasia condition of the intima and media between different treatment groups, and calculating the ratio of intima and tunica media, and the statistical analysis was applied by SPSSl3.0 software. The p values equaling or less than 0.05 were considered statistically significant.Result: 1 Short-term evaluation of intravenous protective effectiveness 1.1 Morphological observationCompared with heparin protective solutions and papaverine hydrochloride protective solutions, there were significant differences in structures and functions of venous grafts endothelial cells in nicorandil protective solution groups. Light microscopy and electron microscopy showed that the venous intimal endothelial cells were falling off least among the three groups, the morphological structures were not obvious abnormal, the intracellular ultrastructure were changed less, the organelle were not obvious edema, and the overall situation were best in nicorandil protective solution groups. 1.2 Intimal integrity assessmentThe intimal coverage scores of heparin saline solution group, papaverine protective group and nicorandil protective solution were respectively(1.533± 0.350),(1.890±0.406),(2.5111±0.220). The three sets of data conformed to the normal distribution and the homogeneity of variance, and the independent samples t test were respectively applied. The P value is greater than 0.05 between heparin saline and papaverine protective solution groups, and the differences were without statistical significance. Nicorandil protective solution group respectively compared with heparin and papaverine protective solution group, the P value was less than 0.05, and the difference has statistical significance. 1.3 Endothelin-1 content in preserving solutions by ESLIA methodThe endthelin-1 contents in heparin saline solution group, papaverine protective solution group, nicorandil protective solution group were respectively(147.649±4.342) ng/L,(141.808±9.314) ng/L, and(77.355± 5.372) ng/L, and the three sets of data all conformed to the normal distribution. Compared with heparin saline and papaverine protective solution groups, the two sets of data conformed to the heterogeneity of variance, and the correction t test could be used P=0.098(P>0.05). The differences were without statistical significance. Nicorandil protective solution group respectively compared with heparin and papaverine protective solution group, and the data conformed to the normal distribution and the homogeneity of variance, and the independent samples t test were applied, and the P value was less than 0.05, and the difference owned statistical significance. 2 Long-term evaluation of intravenous protective effectiveness 2.1 Morphological observationThere were varying degrees of luminal hyperplasia and inflammatory changes in each treatment group. Compared with other two groups, in nicorandil protective solution group hyperplasia of vein graft walls were thinner, the degree of coronary stenosis of the lumens were weaker, and the vascular smooth muscle cell proliferation and matrix deposition was less, and the overall protection was best in the three groups. 2.2 Vein stenosis assessment after two weeksThe intima/media thickness ratios of the heparin saline protective solution group, papaverine protective group, and nicorandil protective solution were respectively(1.431±0.131),(1.349±0.113), and(0.601±0.113). The three sets of data conformed to the normal distribution and the homogeneity of variance, and the independent samples t test were respectively applied. The P value was greater than 0.05 between heparin saline and papaverine protective solution group, and the differences were without statistical significance. Nicorandil protective solution group respectively compared with heparin and papaverine protective solution group, the P value was less than 0.05, and the difference owned statistical significance.Conclusions: Compared with papaverine protective solution and heparin normal saline, nicorandil protective solution could protect the structures and functions of vascular endothelium best. The nicorandil protective solutions could not only control the release of endothelin, but also control postoperative excessive proliferation of endothelial cells and smooth muscle cells, and could improve the graft vascular patency rate. |
PDF Full Text Request