Application of shunting during carotid endarterectomy and impact of collateral circulation on it

Objective To investigate the advantages and disadvantages of shunting during carotid endarterectomy as well as the impact of contralateral carotid occlusion and the patent of anterior and posterior communicating arteries on it.Methods A total of 308 patients who performed carotid endarterectomy from January 2000 to September 2011 were analyzed retrospectively.They were divided into shunting(n=63) and non-shunting(n=245) groups.The intraoperative microemboli,postoperative stroke and mortality in both groups were compared.The degree of contralateral carotid stenosis,the opening ratios of anterior and posterior communicating arteries were compared in both groups.Its impact on shunting was analyzed.Results ①The median microemboli count was 25 in the shunting group and it was 10 in the non-shunting group.There was significant difference between the 2 groups(P0.05).②The incidence of ischemic events within one month after surgery: 1 patient(1.6%) had stroke and 0 died in the shunting group;6 patients(2.4%) had stroke and 4(1.6%) died in the non-shunting group.There were no significant differences for stroke and mortality between both groups(P0.05).③The degree of contralateral carotid artery stenosis before surgery: 8 patients had occlusion,8 had severe stenosis,47 had mild to moderate stenosis or without stenosis in the shunting group;9 patients had occlusion,36 had severe stenosis,and 200 had mild to moderate stenosis or without stenosis in the non-shunting group.The rate of occlusion was significant differences between the 2 groups(P0.05).Both preoperative anterior and posterior communicating arteries of 35 patients(55.6%) did not open in the shunting group and 81(33.1%) did not open in the non-shunting group.There was significant difference between the 2 groups(P0.05).Conclusion Although using shunting may increase the number of microemboli in carotid endarterectomy,but not increase the incidence of perioperative stroke and mortality.The patients with preoperative contralateral carotid artery occlusion or unpatented anterior and posterior communicating arteries,the proportion of using shunting is significantly higher than the other patients.