The Relationship Between Vertebral Artery Severe Stenosis Or Obstruction And Posterior Circulation Ischemia

Background:As the major cause of posterior circulation ischemia (PCI), a high incidence of vertebral artery stenosis has been noted in the past. The diagnosis of vertebral artery stenosis is more and more timely and accurate due to the wide application of MRA and CTA, however, it is still unclear about the risk factors, pattern and prognosis of PGI caused by vertebral artery stenosis.Objective:To investigate differences of risk factors, clinical feature, area of infarction for different sites of vertebral artery stenosis and unilateral or bilateral lesions. We hope to provide evidences for treatment of PCI owing to vertebral artery lesions.Objects and Methods:The medical record and images of patients with vertebral artery occlusive lesions showing≥50% stenosis, who were admitted in ChiFeng City Hospital or The First Hospital Affiliated to Dalian Medical University from January 2012 to January 2014, were selected. Patients were divided into intracranial group, extracranial and combined group, unilateral group and bilateral group according to lesions. Then the risk factors of cerebral vascular disease, pathogenic forms, infracted territory and prognosis were compared between intracranial group and extracranial group, unilateral group and bilateral group.Results:1.A total of 408 cases with vertebral artery occlusive lesions were included.There are 79 asymptomatic patients (19.4%),188 TIA cases (46.1%),65 cases (15.9%) with TIA before stroke and 76 stroke cases (18.6%),88 patients (21.5%) in ICVA (intracranial vertebral artery) group,227 patients (55.6%) in ECVA(extracranial vertebral artery) group including 196 Vlsegement lesions,93 patients in combined group,190 cases(57.6%) in unilateral group and 140 cases(42.4%) in bilateral group. 2.The average age of extracranial and bilateral group are higher than the intracranial and unilateral group (respectively 65.2+8.2 vs 61.4+9.6years, P=0.001; 65.2+8.2 vs 62.4+8.6years,p=0.004); The incidence of hypertension of intracranial group is higher than extracranial group (88.6% VS 70.0%,p=0.000) but coronary heart disease is lower (12.5% VS 25.6%,p=0.012); The incidence of smoking and alcohol history in bilateral group are higher than unilateral group (respectively72.3% vs 56.4%, p=0.002; 44.7% vs 24.3%,p=0.000).3.Extracranial group has a higher incidence of extracrania internal carotid artery stenosis (48.5% VS 19.3%, P=0.000) and subclavian artery stenosis (15.9% VS 2.3%,p=0.001) than intracranial group;while intracranial group has a higher incidence of basilar artery stenosis (12.5% VS 3.5%,p=0.003).4. Extracranial group has a higher incidence of asymptomatic than intracranial group (35.9% vs 8.3%), but incidence of TIA before stroke is lower(8.2% vs 40.3%), the constituent ratio of clinical presentation between two groups is significantly different (p=0.000); Bilateral group has a higher incidence of TIA before stroke than unilateral group (23.7%vs 6.4%), but incidence of asymptomatic is lower (12.1% vs 37.1%), the constituent ratio of clinical presentation between two groups is significantly different (p=0.000).5.The PCI stroke caused by vertebral artery occlusive lesion is more often found in multiple territories (35.5%). the most infarct location of extracranial group is proximal territory alone (35.0%), while the intracranial group is multiple territories (50.0%), the constituent ratio of clinical presentation between two groups is different (p=0.015); the most infarct location of unilateral group is middle territory alone (43.8%), while the bilateral group is multiple territories (44.6%), the constituent ratio of clinical presentation between two groups is different (p=0.000).6. There are 7 cases(15.9%) with mRS scores≥2 in intracranial group and 4 cases (10.0%) in extracranial group, no statistical differences was found in two groups (P=0.423);No statistical differences about patients with mRS scores≥2 was found between unilateral and bilateral groups (18.8% vs 14.5,p=0.570).Conclusion: 1.The incidence of hypertension of patients with ICVA lesion is higher than patients with ECVA lesion; Advanced age,smoking and alcohol are risk factors for bilateral lesions of vertebral artery.2. Patients with ECVA lesion more often found extracrania internal carotid artery stenosis and subclavian artery stenosis than those with ICVA lesion; Patients with ICVA lesion more often found basilar artery stenosis than those with ECVA lesion.3. Patients with ICVA or bilateral lesions more often show stroke, especially TIA before stroke.4. Patients with ECVA lesion or bilateral vertebral artery lesion often suffer multiple territories infarct.