The Pathology Of Watershed Infarction And The Role Of Willis Circle In The Formation Of Watershed Infarction

Watershed infarct(sWSI) involve the junction of the distal fields of 2 nonanastomosing arterial systems. The evidence strongly favors a hemodynamic mechanism for internal WSI. However, the relationships between cortical WSI and hemodynamic compromise appear more complicated. Thus, although severe hemodynamic compromise appears to underliecombined cortical and internal WSI, artery-to-artery embolism may play an important role in isolated cortical WSI.The literature concerned the pathology of WS infarction and the role of compensation blood from Willis circle in the form of WSI in carotid disease.Objective: the literature concerned the mechanisms of WS infarction in carotid disease and the role of compensation blood from Willis circle in the form of WSI. Method:The beginning data of 325 anterior circulation cerebral infarction cases were analyzed, and all had done cerebral vascular examination.After collecting their clinical database,CT,MRI and vascular examination result,stated the mechanisms of WS infarction in carotid disease and the role of compensation blood from Willis circle in the form of WSI. Results: 1 WSI, common cerebral infarct and lacunar cerebral infarct had ICA and MCA stenosis separately accounted for 78.4%,69.7%,23.1%,and ICA and MCA severe stenosis or occlusion separately accounted for 61.5%,53%,7.2%.No matter in stenosis vascular quality or stenosisdegree,WSI group was higher than other group.2 55.8% cortical watershed infarction(CWSI) had ICA and MCA severe stenosis or occlusion,70.8% internal watershed infarcts(IWSI) and 69.2% mixed watershed infarcts (MWSI) were in this condition.IWSI and MWSI had more ICA and MCA severe stenosis or occlusion than CWSI. 11.6%CWSI had no ICA and MCA stenosis but arteriosclerrosis,while 4.9% IWSI and 5.8% MWSI were in this condition, CWSI had more arteriosclerrosis than IWSI and MWSI .There was no difference in ICA and MCA stenosis distribution between 3 WSI groups.25.0% poserior watershed infarcts(PWSI) had posterior circulation vascular stenosis,higher than other WSI groups.3 There was no difference the form of compensation blood between WSI and other infarcts.PWSI had more only anterior compensation blood, IWSI had more both anterior and poserior compensation blood,and MWSI had more only poserior compensation blood.4 Only high blood pressure's history was different between vascular stenosis group and no vascular stenosis group. Conclusion : 1 The most important WSI pathogenesis is low perfusion,and it affect IWSI more than CWSI.2 There is no difference in MCA and ICA stenosis distribution between WSI types. PWSI often suggest severe stenosis of ICA and posterior circulation vascular.3 The form of Willis circle compensation blood affect formation type of WSI.