Patterns of Stroke and Collateralization of the Internal Carotid Artery Occlusion in the Neck

Kang, Dong Wha; Cho, Yong Jin; Roh, Jae Kyu

Abstract

BACKGROUND & PURPOSE: The aim of our study is to evaluate the stroke pattern, the correlation of collateralization with cerebral perfusion and stroke severity, and the utility of transcranial Doppler(TCD) to detect collateral pathways in patients with internal carotid artery(ICA) occlusion in the neck.
METHODS
Thirty-six patients(28 men and 8 women, mean age of 59.6 ? 12.9 years) with ICA occlusion confirmed by transfemoral cerebral angiography(25 patients) or magnetic resonance angiography(MRA, 11 patients) were studied retrospectively. They had no potential cardiac source of stroke. We evaluated the pattern of cerebral infarcts by magnetic resonance imaging, and the number and the patency of collateral vessels, and the degree of perfusion through collaterals by cerebral angiography. The collateral vessels detected by TCD and MRA were compared with those by cerebral angiography.
RESULTS
We found territorial infarcts in 23 patients(64%) and borderzone infarcts in 15(42%). Territorial infarcts(p<0.0001) and borderzone infarcts(p=0.02) occurred more in the ipsilateral hemisphere to the occluded ICA. The prevalence of small subcortical infarcts did not differ between hemispheres. Collateralizations through leptomeningeal anastomosis(p<0.01) and ophthalmic artery(OA, p<0.05) were associated with angiographically reduced cerebral perfusion. Collateralization through OA was also associated with severe symptomatic group(p<0.05); and collateralization through anterior or posterior communicating artery was associated with mild symptomatic group with marginal statistical significance(p=0.097). The number of collateral vessels was associated with neither the degree of perfusion nor the stroke severity. The sensitivity and specificity of TCD to detect collateralization through anterior communicating artery were 100% and 78%, through posterior communicating artery, 67% and 75%, and through OA, 67% and 63%, respectively.
CONCLUSION
Cerebral infarcts related to a proximal ICA occlusion are more likely to be ipsilateral territorial or borderzone. The type of collateralization is more important factor for cerebral perfusion and stroke severity than the number of collateral vessels. TCD is a reliable tool for the evaluation of the collateral vessels in the patients with ICA occlusion.