Association of Vertebral Artery Hypoplasia and Vertebrobasilar Cerebrovascular Accident.

Background and Objectives: Vertebral artery hypoplasia (VAH) is a controversial risk factor for cerebral infarction. The aim of this study was to analyze the prevalence of vertebral artery hypoplasia and to evaluate its association with vertebrobasilar cerebrovascular accidents. Materials and Methods: The study was conducted in the Neurology Departments of the Republican Vilnius University Hospital from 2015 to 2020. Data of 742 subjects (133 patients with posterior circulation infarction or vertebral artery syndrome (PCI/VAS), 80 patients with anterior circulation infarction (ACI) and 529 control subjects with no symptoms of cerebrovascular accident) were analyzed. Ultrasound examination of the extracranial internal carotid and vertebral arteries (VA) was performed, risk factors were recorded. Results: The mean age of the subjects was 64.51 ± 13.02 years. In subjects with PCI/VAS the diameter of VA was smaller, and the prevalence of VAH was higher compared to those in subjects with ACI and in the control group. A higher degree of VAH in subjects younger than 65 years of age increased the risk of PCI/VAS. Subjects with non-dominant VA diameter of 2.7-2.9 mm had 2.21 times higher risk of PCI/VAS, subjects with non-dominant VA diameter of 2.5-2.6 mm had 2.36 times higher risk of PCI/VAS, and subjects with non-dominant VA diameter of 2.2-2.4 mm had 4.12 times higher risk of PCI/VAS compared with subjects with non-dominant VA diameter of ≥3 mm. Among patients with PCI/VAS those with VAH had lower rates of ischemic heart disease compared with patients with normal VA diameter. There was no difference in the rates of other risk factors between PCI/VAS patients with and without VAH. Conclusions: Vertebral artery hypoplasia is not a rare finding in individuals without symptoms of cerebrovascular accident, but more frequent in patients with vertebrobasilar cerebral infarction or vertebrobasilar artery syndrome. Vertebral artery hypoplasia can be considered a risk factor for posterior circulation infarction in subjects under 65 years of age.

Association between systolic blood pressure parameters and unexplained early neurological deterioration (UnND) in acute ischemic stroke patients treated with mechanical thrombectomy.

Background: Neurological deterioration (ND) after mechanical thrombectomy (MT) of acute ischemic stroke (AIS) in anterior circulation is an important complication associated with a poor outcome. Moreover, evident causes of ND may remain unexplained (UnND). Objective: We sought to evaluate the association of the systolic blood pressure (SBP) parameters before MT, during MT, and during a 24-h period after MT with UnND. Methods: We analyzed 382 MT-treated AIS patients in two stroke centers from 2017 to 2019. The patients with unsuccessful recanalization and/or with symptomatic intracerebral hemorrhage after MT were excluded. Multivariate logistic regression analysis was used to identify the SBP parameters that predict UnND. Results: There were 5.9% patients with UnND within 24 h after MT among patients with successful recanalization what comprises 4.9% of all patients who had undergone MT. SBP > 180 mmHg on admission (odds ratio (OR): 4, 95% confidence interval (CI): 1.6-10, p = 0.004) and a drop of SBP below100 mmHg during MT (OR: 4.7, 95% CI: 1.3-17, p = 0.019) were associated with UnND occurrence within 7 days without a significant association with UnND within 24 h. UnND within 7 days was predicted by the episodes of SBP exceeding the level of SBP observed before the groin puncture and occurring over the first 2 h following recanalization (OR: 5, 95% CI: 1.3-19, p = 0.021), an increase of SBP of more than 20% within 2-24 h after MT (OR: 3.4, 95% CI: 1.1-10, p = 0.035), and a drop of SBP below 100 mmHg after MT (OR: 3.2, 95% CI: 1.1-9, p = 0.039). Conclusion: The association between the SBP parameters and UnND depends on the treatment period and the time of UnND occurrence. The J/U resembling relationship between SBP and UnEND was established during a 24-h period after MT.

Association between the posterior part of the circle of Willis and the vertebral artery hypoplasia.

BACKGROUND: It is not clear whether the configuration of the posterior part of the circle of Willis (CW) depends on the proximal part of the vertebrobasilar system. Our aim is to evaluate the posterior part of CW in association with different size of vertebral arteries (VA) in healthy volunteers. MATERIALS AND METHODS: The present study was based on a sample of 923 healthy volunteers who were examined from 2013 through 2018. The duplex ultrasonographic examination of the extracranial vertebral (VA) and carotid arteries was performed. VA was defined as hypoplastic (VAH) when VA diameter in the entire course was less than 2.5 mm. All the participants underwent magnetic resonance angiography (MRA) examination. All the component vessels of the circle of Willis were assessed in each individual. We classified the posterior communicating artery (PCoA) as presence PCoA, absence/hypoplastic PCoA and fetal-type posterior circle of Willis (FCW) in which the major stem of the posterior cerebral artery (PCA) arises from ipsilateral internal carotid artery (ICA). The comparison of the posterior part of CW was made in subjects with normal VA and VAH of a different degree (communicating with basilar artery (VAH-BA) and not communicating with the basilar artery (VAH-PICA)). RESULTS: FCW was found in 15.9% of subjects, bilaterally-in 2.3%. FCW was more frequent in individuals with VAH than in those with normal VA (accordingly, 28.8% vs. 13.5%, p<0.001. Moreover FCW was recorded in 50% of the subjects with VA-PICA in comparison with 13.5% of those with normal VA and 22.8% with VAH-BA, p<0.005. On the contrary, absence/hypoplasia of both PCoA was mostly found in the group with normal VA in comparison with VAH-BA and VAH-PICA (accordingly, 50.7%, 38.6% and 12.5%, p<0.01). CONCLUSION: Individuals with VAH have a different pattern of the posterior part of CW in comparison with those with normal VA. With the increasing degree of VAH, the proportion of FCW increases, while the proportion of absence/hypoplastic of both PCoA decreases.

Association between vertebral artery hypoplasia and posterior circulation stroke.

BACKGROUND: The clinical significance of vertebral artery (VA) hypoplasia is under discussion. The aim of this retrospective study is to evaluate a hypothesis of a possible causal link between VA hypoplasia (VAH) and the incidence of posterior circulation stroke (PCS) or TIA depending on the degree of VAH and vascular risk factors. METHODS: A total of 367 symptomatic (PCS or TIA) and 742 asymptomatic subjects, were selected to participate in the study. The extracranial arteries were examined by ultrasound. VAH was defined as VA diameter in entire course <3 mm, although different degrees of VAH were examined. All the symptomatic patients underwent MRI or CT and MRA or CTA. The study assessed all the subjects in terms of their age, gender, co-risk factors (hypertension, hyperlipidemia, diabetes mellitus, peripheral arterial diseases, atrial fibrillation, myocardial infarction), as well as height of 180 healthy volunteers. RESULTS: VAH, regardless of the degree of severity, was more frequent in patients with non-cardioembolic PCS or TIA rather than in asymptomatic patients. The increasing degree of hypoplasia in patients under 65 years of age was a predictor of PCS/TIA, OR = 1.8, 95% CI: 1.3-2.5; p < 0.001. In subjects older than 65 years of age, this association failed. Only in patients aged under 50, VAH was significantly more frequent in the TIA group rather than in the PCS group (68.2% and 50%, respectively; p = 0.047). The optimal VA diameter cutoff point separating PCS/TIA and asymptomatic group was 2.7 mm. This value may vary in different populations, because VA diameter showed a significant dependence on sex as well as anthropometric parameters (height). With the increasing degree of VAH, the likelihood of the occurrence of the distal VA part stenosis/occlusion was growing (OR = 1.6, 95% CI: 1.2-2.1; p = 0.002). The distal VA stenosis/occlusion was likely to occur where the VA diameter was <2.2 mm. CONCLUSIONS: The impact of the VAH on PCS/TIA and its pathogenetic mechanism was significantly influenced by age. The cutoff point of VA diameter, affecting the occurrence of PCS in different populations may vary because VA diameter depends on gender and anthropometric parameters (especially height).

[Risk of stroke and death after carotid endarterectomy]. / Galvos smegenu insulto ir mirties rizika po vidines miegoarterijos endarterektomijos.

OBJECTIVE: The benefit of carotid endarterectomy is highly dependent on surgical risk. The aim of this study was to evaluate the incidence of stroke and death after carotid endarterectomy, risk factors for poor outcomes, and importance of surgeon's competence. MATERIAL AND METHODS: A total of 790 carotid endarterectomies performed in the Vilnius University Emergency Hospital between 1995 and 2006 were analyzed. Risk factors, neurological symptoms, comorbidities, radiologic and angiographic findings, morbidity and mortality, experience and volume of a vascular surgeon were prospectively recorded in a database. Univariate and multivariable logistic regression and receiver operating characteristic curves were used to analyze the data. RESULTS: Among the 790 cases studied, in-hospital mortality was 2.2%, and stroke morbidity was 2.4%. Postoperative complications were more common in patients with diabetes mellitus than without (12% vs. 3.4%, P<0.001) and in patients with any stroke than in patients with nonspecific symptoms (10.7% vs. 1.4%, P<0.02). The postoperative stroke rate was 10% for a surgeon who performed <6 carotid endarterectomies per year and 4.6% for a surgeon who performed ≥6 carotid endarterectomies (P=0.02). In the multivariate logistic regression, combined mortality and stroke was independently predicted by diabetes mellitus (OR, 3.51; 95% CI, 1.60-7.66; P=0.002), any stroke (OR, 4.14; 95% CI, 1.57-10.91; P=0.004), and low-volume surgeon (OR, 0.32; 95% CI, 0.13-0.78; P=0.013). The receiver operating characteristic curve analysis showed an overall predicting value of 0.72. CONCLUSIONS: Diabetes mellitus, any stroke, and low-volume vascular surgeon were significant predictors for poor outcome after carotid endarterectomy.

[The impact of acute cerebral blood flow disturbances on platelet aggregation]. / Uminiu smegenu kraujotakos sutrikimu itaka trombocitu agregacijos intensyvumui.

OBJECTIVE: To determine the changes in platelet function, manifesting as deviations of their aggregation intensity, in persons with acute ischemic stroke and transient ischemic attacks, to evaluate the effect of aspirin on platelet aggregation, dependent upon degree of cerebral blood flow disturbances and patient's gender, and to compare these changes with those in healthy persons. MATERIAL AND METHODS: We examined 50 patients aged 33 to 98 years (mean age, 63.7+/-2.1 years; 20 men and 30 women) with cerebral blood flow disturbances during acute period (18 with transient ischemic attacks and 32 with ischemic stroke). The diagnosis was confirmed by computer tomography and other clinical examinations. Adenosine diphosphate-, epinephrine-, and collagen-induced platelet aggregation was assessed in platelet-rich plasma. Twelve patients used aspirin at prophylactic doses (100-150 mg/d), and 38 patients did not use. The control group consisted of 25 healthy persons aged 31-64 years (mean age, 45.4+/-1.9 years; 17 men and 8 women). RESULTS: Increased platelet aggregation induced by all three inducers was significantly more frequent in stroke group. Platelet reaction to collagen was more expressed. Aspirin suppressed aggregation, but did not protect against development of ischemic stroke. Higher activity of platelet function during ischemic stroke was observed in platelets from men's plasma. CONCLUSIONS: During acute period, platelet aggregation in platelet-rich plasma statistically significantly increases in the stroke group, independently of the severity of the disease. A part of patients, using recommended dose of prophylactic aspirin, developed ischemic stroke. The effect of aspirin on platelets was more pronounced in women than men.

[Results of carotid endarterectomy in diabetic patients]. / Serganciuju cukriniu diabetu vidines miego arterijos endarterektomijos rezultatai.

UNLABELLED: Patients with diabetes mellitus have been shown to have an increased incidence of complications after major vascular surgery. The objective of this study was to evaluate the results of carotid endarterectomy in diabetic patients, to determine if results differ from nondiabetic patients, and to examine the risk factors for poor outcome among diabetic patients. MATERIAL AND METHODS: We reviewed all carotid endarterectomies performed in Emergency Hospital of Vilnius University. From 1995 to 2005, 707 carotid endarterectomies were performed. Of these, 100 operations were performed in diabetic patients (14%) and the remaining 607 in nondiabetic patients. RESULTS: Diabetic patients were younger (P<0.05) and were obese more often (P<0.001), they smoked less often (P<0.001) than nondiabetic patients. Diabetics were more likely to have severe bilateral carotid stenosis than nondiabetic patients (P<0.01). Postoperative complications (stroke) were more common in diabetic patients than in nondiabetic patients (12.0% vs. 3.4%, P<0.001) as well as intracerebral hemorrhages (3.0% vs. 0.3%, P<0.001); no perioperative myocardial infarction was found in diabetic patients. Risk factors for complications were age >/=75 (odds ratio (OR) 2.2; 95% confidence interval (CI)=1.0-4.9), smoking (OR 2.7; 95% CI=1.8-4.2), obesity (OR 6.1; 95% CI=3.9-9.5), and bilateral carotid stenosis (OR 2.1; 95% CI=1.3-3.6). CONCLUSION: Diabetes mellitus significantly increased the risk of mortality and intracerebral hemorrhage but not myocardial infarction. It should be taken into consideration in making decisions about the performance and perioperative management of carotid endarterectomy.

[Models of intracranial aneurysms for angiographic imaging modalities. A technical note]. / Dirbtiniu intrakranijines aneurizmos modeliu kurimas angiografiniams tyrimams.

OBJECTIVE: To delineate technical aspects of vascular models with intracranial aneurysm in vitro production, suitable for angiographic imaging. MATERIAL AND METHODS: Wax (K2 exact, S-U-CERAMO-CAPS-WAX), Girtl's mass, gelatin, and silicone (Silicone 10015 Den Braven, Elastosil 7683/25, Elite Double 32 Shore-A, Rema-Sil) were used for model production. Construction of models was based on T-shaped plastic tube connections and lost core techniques. Images of rotational angiography, glass tubes with aneurysm, and casts obtained in human specimen were used as samples of cerebral arteries. RESULTS: Technical aspects of vascular models production were delineated in experience of eight silicone models produced. M1 was hand made with basilar tip aneurysm; M2 was obtained according to angiography images with internal carotid artery supraclinoid part bifurcation to anterior and middle cerebral artery aneurysm. BM1 and BM2 casts were made using glass tubes with lateral aneurysm, M3--from T-shaped plastic tubes with lateral aneurysms. M4, M5, and M6 were formed using casts obtained in human specimen with basilar tip aneurysm. CONCLUSIONS: Silicone of two components is practical for casts of cerebral arteries in human specimen production. Gelatinous solution 50 degrees C diluted 1:1 with water can be used for copies of arterial casts production. Wax materials are unsuitable for making casts in a human specimen.

[Carotid artery atherosclerotic stenosis, plaque structure and stroke]. / Vidines miego arterijos aterosklerozine stenoze, ploksteles struktura ir galvos smegenu insultas.

OBJECTIVES: The main indication for carotid endarterectomy is severity of stenosis carotid artery. Several studies have shown the relationship between carotid plaque morphology and cerebrovascular disorders. The purpose of this study was to evaluate the structure of carotid plaque and correlate carotid plague morphology with neurological symptoms, stroke risk factors, severity of carotid stenosis and operative stroke. METHODS: Operative specimens of 262 carotid plaques were examined macroscopically. Plague morphology was characterized as either heterogeneous or homogeneous. Stroke risk factors, cerebrovascular symptoms, severity of carotid stenosis and risk for mortality and operative stroke were compared between symptomatic and asymptomatic patients with heterogeneous and homogeneous plague. RESULTS: Heterogeneous plaques were present in 198 (75%) of 262 arteries. Heterogeneous plaques were found in 121 symptomatic and 77 asymptomatic patients (p<0.001). Homogeneous plagues did not differ in symptomatic and asymptomatic patients. The structure of plaque did not correlate with any severity of stenosis. There were no significant differences in age, sex, smoking and arterial hypertension between heterogeneous and homogeneous groups. Higher level of fibrinogen but not hypercholesterolemia was associated with heterogeneity of plaque. Postoperative stroke was mainly present in the patients with heterogeneous plaques, but the difference was not statistically significant. CONCLUSIONS: Heterogeneous plaques were present in 75 % of patients with carotid artery stenosis. Heterogeneous plagues were associated with cerebrovascular symptoms more often than homogeneous ones. Plague structure did not correlate with severity of carotid artery stenosis and operative stroke was not associated with plaque heterogeneity. These findings suggest that plague heterogeneity should be considered in selecting patients for carotid endarterectomy.

[Atherosclerosis-related stroke: risk factors, location, outcome]. / Aterosklerozines kilmes insultu rizikos veiksniai, lokalizacija, ligos baigtis.

We compared the characteristics of 1114 patients with first stroke caused by atherosclerosis with characteristics of 2159 patients with stroke due to other etiology. Stroke due to atherosclerosis with stenosis more often than stroke due to atherosclerosis unthout stenosis and stroke due to other etiology occurred in the caroted territory (respectively 66.9%, 55.2% and 61.7%, p < 0.001) and border-zone (respectively 7.2%, 0.5% and 1.1%, p < 0.001). Stroke due to atheroscerosis unthout stenosis more often than strokes caused by other etiologies occurred in the vertebrobasilar territory (respectively 40.1%, 20.2% and 29%, p < 0.001). The proportion of patients with death or major disability was greater in the group atherosclerosis with stenosis (18%) than in the group atherosclerosis without stenosis (9.4%, p < 0.001).

[Complications of carotid endarterectomy]. / Miego arterijos endarterektomijos komplikacijos.

BACKGROUND AND PURPOSE: Carotid endarterectomy has been shown to be beneficial in patients with high-grade carotid stenosis. This benefit will be realized only if the operation is performed safely. We determined the ratio of operative complications and sought to identify the risk factors for operative stroke and death from carotid endarterectomy. METHODS: Two hundred fifty seven patients underwent carotid endarterectomy during 1995-1999 years in Vilnius emergency hospital. Nineteen potential risk factors for operative complications were examined. RESULTS: Mortality of endarterectomy was 2.7%, the overall risk of stroke and/or death was 4.3%. In multivariate logistic-regression models a symptom status (recent history of stroke) and angiographic features (contralateral stenosis 70% and more) were as independent risk factors for operative stroke and death. CONCLUSIONS: The risk of stroke and death from carotid endarterectomy is related to clinical and angiographic characteristics. These observations may help clinicians to estimate operative risks for individual patients.