ABSTRACT
Objective To establish the carotid fusiform aneurysm model in rabbits carrying similar characteristics of human intracranial aneurysms by using induction method with porcine pancreatic elastase. Methods Twenty-five New Zealand white rabbits were randomly divided into normal control group (n=5), saline control group (n = 5) and study group (n = 15). The rabbits of the study group were randomly and equally subdivided into 7-day subgroup, 14-day subgroup and 21-day subgroup. By using induction method with porcine pancreatic elastase to digest right common carotid the fusiform aneurysm model was established in all the rabbits of the study group. DSA examination , HE staining and elastic fiber staining pathologic examination were carried out at 7, 14 and 21 days after the procedure to observe the imaging and pathologic changes of the fusiform aneurysm models. Results DSA angiography showed that the mean vascular diameters of the normal control group and the saline control group were (1.64 ± 0.17) mm and (1.66 ± 0.24) mm respectively. The mean length and width of the fusiform aneurysm of the 7-day subgroup, 14-day subgroup and 21-day subgroup were (19.33 ± 1.65) mm and (2.86 ± 0.21) mm, (19.66 ± 1.18) mm and (3.95 ± 0.54) mm, and (19.84 ± 0.82) mm and (4.03 ± 0.95) mm, respectively. Pathologically, rupture of internal elastic membrane, disordered structure of tunica media smooth muscle and distortion of cell shape were observed in the rabbits of 7-day subgroup. Gradually stabilized aneurysmal lumen intimal hyperplasia was seen in the rabbits of 14-day subgroup. Remarkable structure changes at the aneurysmal neck-cavity junction were found in the rabbits of 21-day subgroup. Elastic fiber staining demonstrated that strikingly thinned elastic layer was observed in the rabbits of 7-day subgroup, gradually thinning elastic layer at the aneurysmal neck-cavity junction was seen in the rabbits of 14-day subgroup, and the thinned elastic layer became stable in the rabbits of 21-day subgroup. Conclusion Using simple surgical method combined with porcine pancreatic elastase to digest vascular wall, carotid fusiform aneurysm models can be reliably established in New Zealand white rabbits which carry similar morphologic and pathologic characteristics of human intracranial aneurysms.
ABSTRACT
Objective To investigate the feasibility and effectiveness of inducing rabbit common carotid fusiform aneurysms via the common carotid extravascular digestion method. Methods Sixteen New Zealand white rabbits were randomly assigned into either an experiment group ( n=12 ) or a control group (n=4). Porcine pancreatic elastase 80-400 U were used to incubate and digest 2 to 4 cm segment of artery distal to the origin of right common carotid artery. One week after modeling,intravenous angiography was performed and the length and width of fusiform dilatation of common carotid artery were measured. The fusiform dilated artery was examined with hematoxylin and eosin staining and the vascular morphological changes were observed with scanning electron microscope. Isotonic saline solution was used to incubate common carotid arteries of the 4 New Zealand white rabbits in the control group. After one week,the same method was used to observe the lumen of common carotid artery and intimal changes. Results After the digestion of common carotid artery adventitia,the angiography of 12 New Zealand white rabbits of the experimental group revealed fusiform dilatation of common carotid artery of the 10 model rabbits. The widest diameter of the fusiform artery was 3. 70 ± 0. 32 mm;two rabbits had common carotid artery occlusion. Compared with the control group,the right common carotid artery diameter enlarged significantly in the experimental group (1. 80 ± 0. 16 mm,P<0. 01). The HE staining showed that the lumen widened, adventitia and media reduced. Scanning electron microscope showed intimal inflammatory injury and thrombus attachment. Conclusion Using porcine pancreatic elastase to digest the adventitia of common carotid artery can make fusiform dilatation of common carotid artery in rabbits. Using this method may effectively induce a model of fusiform aneurysm,and it has certain feasibility.