Bilateral common carotid artery ligation for creating basilar terminus aneurysm model in rabbits: A preliminary study

Objective To use bilateral common carotid artery ligation for creating an aneurysm model of the basilar terminus in New Zealand white rabbits. Methods Twenty-sixadult New Zealand white rabbits were subjected to sham operation or bilateral common carotid artery ligation to increase basilar artery flow. Basilar artery flow velocity was monitored by transcranial Doppler before the operation, and 1 d, 1 week, and 4 weeks after surgery. Cerebral angiography was performed 4 weeks after surgery to observe the changes of basilar arteries. The basilar arteries were harvested to observe the morphological changes of the arteries and the histological characteristics of the bifurcation tissues 1 week and 4 weeks after the surgery. Results All animals survived in the sham group, and 80% (16/20) of the animals survived in the experimental group. Thebasilar artery flow velocity increased sharply one day after operation (increased by 226%) in the experimental group, and it kept increasing 1 week after the operation until reaching a stable state 4 weeks after operation. The basal arteries were dilated obviously and displayed tortuous formation after one week in the experimental group, but there was no such change in the sham group. All rabbits in the experimental group presented with thinned media and absent, disrupted or thinned internal elastic lamina near the basilar terminus. Conclusion Blood flow increase at the basilar bifurcation caused by ligation of the bilateral common carotid arteries can lead to aneurysmal change at the basilar terminus of New Zealand white rabbits.