[Collateral supply in patients with severe carotid stenosis]

To determine the collateral supply is sufficiency or not in patients with carotid stenosis.

Fifteen consecutive patients with carotid stenosis underwent carotid endarterectomy (CEA). We evaluated the patent collateral pathways through the anterior and posterior communicating arteries or the ophthalmic artery (ACoA; PCoA; OA) with TCD before CEA. A total of 15 subjects were monitored the mean velocity of the ipsilateral middle cerebral artery (mvMCA) by TCD and simultaneously detected stump pressure (SP) after cross clamping carotid artery during the operation.

Three subjects patent anterior communicating artery; 5 cases patent posterior communicating artery; 6 of 15 patent OA. SP > or = 50 mm Hg in 8 cases and SP < 50 mm Hg in 7 patients were detected after cross clamping. The decrease of the ipsilateral mvMCA is less than 30% of baseline in 11 cases. Both TCD preoperatively and SP during CEA indicated collateral blood adequately or not in 9 cases. Results of 12 patients evaluated collateral supply by means of SP and mvMCA changes were common.

TCD is a useful tool for the evaluation of the sufficiency of collateral circulation in patients with carotid artery severe stenosis, especially monitoring the ipsilateral mvMCA changes during carotid endarterectomy.