Study Of The Correlation Between Collateral Circulation And Vertebral-basilar Artery System In Acute Infarction

Objectives: Cerebral artery stenosis or occlusion is one of the important ressons for ischemic cerebrovascular disease. And cerebral infarction caused by vertebral-basilar artery stenosis or occlusion is often leading to a high degree of death and disability. But some patients of ischemic cerebrovascular disease found vertebrobasilar artery stenosis or occlusion during the DSA examination often have minor clinical symptoms and good recovery. Beacause the structure of the brain blood vessels is complex and there are a lot of collateral circulations in the brain. As the existing of collateral circulation, neurological deficits and prognosis of ischemic cerebrovascular disease causing by cerebral artery severe stenosis or occlusion played a significant changing.Rich collateral circulation may protect to the brain. In recent years, there are a large number of reports on the collateral circulation of internal carotid artery stenosis or occlusion .but collateral circulation of the vertebrobasilar system and the relationship between the collateral circulation of the vertebrobasilar system and the prognosis have rarely been reported. This study is on the collateral circulation of vertebrobasilar artery stenosis or occlusion and its effects on neurological impairment and prognosi, which provide an important basis for selecting the clinical treatment options and judging the prognosis.Methods: We review the medical records of 83 patients with vertebrobasilar artery stenosis or occlusion confirmed by the DSA who are admitted to the department of neurology in the first hospital of Jilin University between March 2004 and November 2009. These patients are respectively grouped according to the availability of collateral circulation, collateral type, the degree of vascular stenosis and the number of vascular lesions. We use the NIHSS score and the MRS score as a standard to analyzed and compared the difference on neurologic impairment, a good prognosis, mortality statistically of each group. And obtaining the types of collateral circulation of vertebrobasilar artery stenosis or occlusion.Result:(1) Of 83 patients, There are very significant statistical significances in admission NIHSS score with 24 hours of admission and MRS score of onset 14 days (P = 0.005, 0.000,0.010) between group with collateral circulation and group without collateral circulation. There also have very significant statistical significances in the degree of neurological deficit, a good prognosis and mortality at the 14 days of onseting (χ2 = 9.115, P = 0.003;χ2 = 8.400, P = 0.004;χ2 = 10.362, P = 0.001 <0.01).(2) There is no significant statistical significance in mortality between group of major collateral circulation and group of Secondary collateral circulation (P> 0.05). But when group of major collateral circulation and group of Secondary collateral circulation compared with the group of no collateral circulation respectively,differences is statistically significant (P = 0.033 <0.05, P = 0.007 <0.01).(3) There is very significant statistical significance in neurologic impairment at admission between the group of BA stenosis and the group of VA stenosis (χ2 = 8.285, P = 0.004 <0.01). Bu there is no significant statistical significance in prognosis (P> 0.05).(4) Thereis no significant difference between the different degree of VBA stenosis and availability of collateral circulation (P> 0.05). But there exist significant difference between the different number of VBA stenosis and availability of collateral circulation (χ2 = 6.273, P = 0.012 <0.05).(5) 83 patients had collateral circulation 40 cases,including posterior communicating artery 14 cases (33%), leptomeningeal of posterior inferior cerebellar artery 16 cases (38%), leptomeningeal of posterior cerebral artery 4 cases (10%), thyrocervical trunk and vertebral artery anastomosis in 2 cases (10%), muscular branches of the external carotid artery 3 cases (7%), thick of basilar artery branches 1 case (2%).Conclusions: (1) Patients with collateral circulation have more little neurologic impairment and better prognosis than patients without collateral circulation when vertebral basilar artery stenosis or occlusion occur.(2) The stenosis or occlusion of bilateral vertebral artery is more easy to form progressive stroke.(3) Collateral circulation is related to the number of vascular stenosis in system of vertebrobasilar artery.(4) Posterior communicating artery and leptomeningeal of posterior inferior cerebellar artery are main Collateral circulation in vertebrobasilar artery stenosis or occlusion. anastomosis of thyrocervical trunk and vertebral artery are extremely rare.