| Objective:Using dual-source CT to research normal collateral anastomosis of vertebral basilar artery and compensatory collateral circulation in patients with severe stenosis or occlusion of vertebral basilar artery,discusses compensatory methods and features of collateral circulation open when vertebral basal artery severe stenosis or occlusion,to provide the reference for intravascular interventional therapy for clinical and various possibility of bypass surgery.Methods:Collecting a total of103cases as the research object, which were checked in the first people’s hospital of yunnan province dual-source spiral CT room line of head and neck DECTA from July25,2010-2012, July25,posterior circulation ischemia,vertebral basilar artery stenosis degree or greater in70%,and a60healthy that were checked at random over the same period on the DECTA. normal vertebral basal artery as the controls. We counted vascular lesion, the presence of collateral circulation, the types of collateral circulation, degree of stenosis and pathology of the quantity, the posterior circulation cerebral infarction in groups, to explore Compensatory collateral circulation patterns when vertebral basal artery severe stenosis or occlusionResults:(1)103patients and60normal controls were successfully completed DECTA examination, only2cases appeared mild allergic reactions such as nausea, dizziness, numbness in his right hand, rapid heart rate, skin rash, the others had no obvious discomfort.(2)ln60normal controls,28cases of vertebrobasilar collateral anastomosis were observed, in which there were13cases of occipital artery and deep cervical artery anastomosis which flowed into the V3segment of the vertebral artery,3cases of branch of the occipital artery and vertebral artery anastomosis,8cases of branch of deep cervical artery and vertebral artery anastomosis, and4cases of the ascending cervical artery of thyrocervical trunk and vertebral artery anastomosis. While there were32cases in which no significant collateral anastomoses were observed.(3)In103cases, there were33patients (32.05%) with the whole vertebral artery multiple severe stenosis or occlusion,62patients (60.19%) with the severe extracranial vertebral artery stenosis or occlusion (including the33patients with the whole vertebral artery lesions),74patients (71.84%) with severe intracranial vertebral artery stenosis or occlusion (including the33patients with the whole vertebral artery lesions), and14patients (13.95%) with basilar artery severe stenosis and occlusion.(4)Among103patients,57cases of opening and compensatory of collateral circulation were observed, in which there were18cases of two or more opening and compensatory collateral circulations. Classified by collateral, there were34patients with posterior communicating artery compensation,4patients with contralateral vertebral artery thickening compensatory,7patients with deep cervical artery and vertebral artery anastomosis compensatory,5patients with ascending cervical artery of thyrocervical trunk and vertebral artery compensatory,4patients with occipital artery and vertebral artery anastomosis compensatory,2patients ascending pharyngeal artery and vertebral artery anastomosis compensatory,3patients with anterior spinal artery thickening compensatory, middle cerebral artery and posterior cerebral artery leptomeningeal anastomosis (moyamoya disease),1patients with anterior inferior cerebellar artery, posterior inferior cerebellar artery and posterior cerebral artery leptomeningeal anastomosis,1patients with posterior inferior cerebellar artery and posterior cerebral artery leptomeningeal anastomosis.(5)Among103patients, whether there was a posterior circulation infarction has a statistically significant difference with collateral circulation. No collateral circulation had a higher probability of occurrence of cerebral infarction, the difference was statistically significant (P<0.05). The difference between the degree of vertebrobasilar stenosis and collateral circulation was statistically significant (p<0.05). And the number of different vertebral artery lesions had no statistically significant correlations with collateral circulation.Conclusions:1) Dual source spiral DECTA has high spatial resolution. Wide range of thin-layer volume scanning, MIP, MPR, VR and other technologies can identify subtle anatomical structure of≥0.4mm, and can display small branches of the vertebral basilar artery anastomosis more clearly, has a high sensitivity, specificity and accuracy.2) It can be observed in the descending branch of the occipital artery and deep cervical artery muscular branches anastomosis and then import V3segment of the vertebral artery in normal extracranial vertebral artery, Occipital artery branches directly anastomosis with the vertebral artery, deep cervical artery directly anastomosis with the vertebral artery, thyrocervical trunk and its branches carotid anastomosis with the ascending aorta and vertebral artery.It indicates that the vertebrobasilar in normal physiological conditions have various forms of anastomosis between blood vessels and the surrounding.These blood vessels are smaller under normal circumstances.These potential collateral vascular anastomosis are in a dormant state. When a branch of intracranial and extracranial vascular appear stenosis progressive, these collateral vascular anastomosis gradually compensatory blood supply.It can effectively provision of collateral blood flow and compensatory only when Vascularized diameter>lmm.3)It can be observed several vascular anastomosis above or some other vascular anastomosis in pathological state of Severe stenosis of vertebrobasilar or blocking. It will appear collateral circulating and playing a compensatory role only when Vascularized diameter enlarge and the diameter>1mm. Intracranial vertebral artery collateral circulation and compensatory mainly in posterior communicating artery, and posterior inferior cerebellar artery.Extracranial compensatory mainly in the thyrocervical trunk, deep cervical artery, occipital artery and vertebral artery anastomosis.4) When vertebrobasilar severe stenosis or blocking,the probability of occurrence of cerebral infarction in patients without collateral circulation is larger than in patients with collateral circulation.Vertebrobasilar stenosis is higher, the greater the probability of appearance of collateral... |
