The Formation of Collateral Circulation after Carotid Stenosis or Occlusion

Objective:To study the formation of collateral circulation after stenosis or occlusion of the carotid arteries.Methods:The clinical data of 142 patients with carotid stenosis or occlusion confirmed by DSA were studied.The collateral circulation and it's association with brain imaging changes were analyzed retrospectively.Results:Seventy-eight patients(54.9%) formed collateral circulation,in which 44 cases were by Willis arterial circle(56.4%),5 by extracranial arteries(6.4%),and 29 by both the Willis arterial circle and extracranial arteries(37.2%).The formation of the collateral circulation was positively related to the degree of stenosis(P0.05),in which the incurrence in patients with double stenosis was significantly higher than that with single stenosis(76.5% vs 52%).Joint compensation from both the cranial and extracranial arteries were more common in patients with unilateral occlusion(P0.05).Compensation with Willis arterial circle was the main way in patients without cranial artery stenosis.However,joint compensation was the main style in patients with cranial artery stenosis.The formation of collateral circulation correlates with the types of cerebral infarction.Watershed infarction was preferentially observed in patients with collateral circulation.Conculsion: The degree of cerebral artery stenosis determines the formation of cerebral collateral circulation which was closely associated with the types of cerebral infarction.