Producing Aneurysm Models Of Rabbit Carotid Artery By Applying Elastase

Through dropping different density of elastase solution on the adventitiaes of rabbits?CCAs during the experiment, the influence on the artery wall by elastase is observed. As a result, a better way of producing animal model of aneurysm is obtained. Elastase was resolved by NS or PBS. A series of elastase solution with different density were dropped randomly on the different parts of CCAs?adventitia. The another lateral artery was used as a control. Changes of local artery diameter were observed with a microscope and measured at a different time respectively. The affect on the artery wall whether elastase is resolved by NS or by PBS is not significantly different. When the activity density of elastase solution is 1 5U/ ~ 1 , the action of inducing aneurysms is the most distinguished. When the density is lower than that, the ability of inducing aneurysms reduces. While the density is higher than that, local artery wall is apt to ooze blood, and thrombus is easy to form. The ability of inducing aneurysms is negatively relevant to the density. Aneurysms can't be reduced in control groups. The elastase NS solution with density of 1 .5 ii I was used in inducing furcation抯 and aneurysms. Parts of aneurysms wrapped up by emulsion film after operation imitating subarachnoid cavity. Having observed for one or three days, whether or not applying the method of wrapping up aneurysms by emulsion film, the sizes of aneurysms are not influenced significantly.Fusiform aneurysms and wide-neck aneurysms are easy to make by dropping elastase solution on the artery wall. However, furcation aneurysms and narrow-neck aneurysms did not form during three days. Pathological examination shows that the internal elastic membrane and the medial smooth muscle of the aneurysm are ruptured, dissolved, and even disappeared in more cases. The wall of aneurysm is only composed of a thin layer of fibroid tissue. A few of aneurysms combine with thrombus. ECAs and STAs were further used to induce narrow-neck aneurysms. Anticoagulation should performed. The proceeding sequence of anticoagulation and induction can influence obviously on the formation of an aneurysm. The experiment has showed that adopting the method of dropping elastase solution on the artery ~vall, aneurysms can form in short time ?from 10 to 15 minutes. Fusiform aneurysms or wide-neck aneurysms can be induced easily. Narrow-neck aneurysms can be made by ligated the distal portions of fusiform aneurysms which formed through utilizing branchs of arteries with anticoagulation. The pathologic changes of aneurysms are similar to the changes of human's cerebral aneurysms. Comparing with others, this kind of method is relatively simple, quick, stable and repeatable. However, furcation aneurysms can not be induced in three days. The experiment indicates that elastase plays an important role in the formation of an aneurysm, and provides the possibility of making researches into prevention and treatment cerebral aneurysms by medicine which can inhibit the decomposion of elastin.