Preparation improvement of lateral wall aneurysm model of common carotid artery in experimental rabbits

Objective: To improve the preparation procedure of lateral wall aneurysm model of common carotid artery in experimental rabbits, and assess its success rate and patency rate of the common carotid artery after receiving stent placement. Methods: A total of 20 New Zealand rabbits were used for this study. The left common carotid artery of the New Zealand rabbit was ligated after breeding for one week. The arteries of the neck were examined with 3.0 T MRA to observe the changes of carotid and vertebral arteries one month after ligation. Finally, an anastomosis between venous pouch and common carotid artery was accomplished by using interrupted extroversion suture method with 6-0 microsuture, and the lateral wall aneurysm model of common carotid artery was thus established. Before, immediately after and 3, 6 months after the stent implantation the carotid angiography was carried out to check the results. Results: The left common carotid arteries were successful ligated in all twenty New Zealand rabbits. Before and one month after the ligation the mean diameter of right carotid middle segment was (2.35 ± 0.08) mm and (2.89 ± 0.22) mm respectively, the difference was statistically significant (P < 0.001). MRA performed one month after ligation revealed that in 17 rabbits the right carotid was strikingly thickened and bilateral vertebral arteries were slightly thickened; in 3 rabbits no obvious thickened carotid was found, while bilateral vertebral arteries were evidently thickened. The lateral cystic aneurysm models in common carotid artery were established in 17 rabbits, and all the model rabbits were healthy and alive. DSA performed before the implantation of covered-stent showed that all aneurysms were clearly displayed and right carotid was patent. In 4 cases, a small amount of thrombus could be seen within the aneurysmal cavity, but no spontaneous total occlusion of the aneurysm was observed. Angiography performed immediately after the implantation of Willis or magnesium alloy-covered stent revealed that the aneurysm was obstructed, with the right carotid being patent. DSA performed 3 months after stent placement showed that the right carotid artery remained patent in 16 rabbits and was obstructed in one rabbit. DSA performed 6 months after stent placement demonstrated that the right carotid artery still remained patent in 16 rabbits. The success rate of the preparation of aneurysm model was 100% (17/17), the right carotid patency rate after implantation of covered stent was 94.1% (16/17). Conclusion: The modified procedure for the preparation of the lateral aneurysm model on common carotid artery in rabbits can improve the success rate as well as the patency rate of the right common carotid artery after covered stent implantation. (authors)