Basilar Artery In Patients Research Articles

Correlation Between Carotid Stenosis and Pulsatile Index Measured by Transcranial Doppler.

Carotid atherosclerosis is often mentioned as one of the main causes of stroke. Currently, embolization is considered the most common mechanism that causes ischemic strokes due to atherosclerotic lesions in the carotid artery. Transcranial Doppler (TCD) ultrasound provides relatively inexpensive, noninvasive, real-time measurement of blood flow characteristics and cerebrovascular hemodynamics within brain arteries. The pulsatile index measured by transcranial Doppler is a parameter that indicates the degree of elasticity of the blood vessels of the brain. The aim of this study is to determine the relationship between the value of the pulsatile index of the middle cerebral artery and the basilar artery in patients with carotid stenosis using transcranial Doppler and the value of the pulsatile index in relation to the degree of carotid stenosis. The study involved a total of 140 patients examined at the Color Doppler and Transcranial Doppler Department of the Neurology Department of the General Hospital "Prim Dr. Abdulah Nakas" Sarajevo The patients were divided into two groups. The research was conducted in the General Hospital "Prim. dr. Abdulah Nakas" in Sarajevo at the Department for Color Doppler and Transcranial Doppler of the Department of Neurology and included patients examined in the period from February 2022 to December 2022. All patients underwent extracranial Doppler of the carotid arteries and transcranial Doppler of the middle cerebral artery and basilar artery. The mean values of PI in ACM in the total sample were statistically significantly lower in patients with stenosis up to 50% compared to the average in patients with stenosis over 50%. Average values of PI in AB in the total sample were statistically significantly lower in patients with stenosis up to 50% compared to the mean values in patients with stenosis over 50%. Transcranial Doppler findings showed an increased pulsatile index in patients who had carotid stenosis greater than 50% compared to patients with mild carotid stenosis. The study showed that in clinical work it would be necessary to introduce the pulsatile index as an indispensable neurosonological parameter that would be included in the findings of the transcranial Doppler and thus objectify the potential risk of a cerebrovascular ischemic event.

Effects of abnormal vertebral arteries and the circle of Willis on vertebrobasilar dolichoectasia: A multi-scale simulation study

BackgroundVertebrobasilar dolichoectasia is a rare cerebrovascular disease characterized by obvious extension, dilation and tortuosity of vertebrobasilar artery, and its pathophysiological mechanism is not clear. This study focused on local hemodynamic changes in basilar arteries with typical vertebrobasilar dolichoectasia, together with unbalanced vertebral arteries and abnormal structures of the circle of Willis, through multi-scale modeling. MethodsThree-dimensional models of 3 types of vertebrobasilar arteries were constructed from magnetic resonance images. The first type has no vertebrobasilar dolichoectasia, the second type has vertebrobasilar dolichoectasia and balanced vertebral arteries, and the third type has vertebrobasilar dolichoectasia and unbalanced vertebral arteries. A lumped parameter model of the circle of Willis was established and coupled to these three-dimensional models. FindingsThe results showed that unbalanced bilateral vertebral arteries, especially single vertebral artery deletion mutation, might associate with higher wall shear stress on anterior wall of basilar artery in patients with vertebrobasilar dolichoectasia. And unbalanced bilateral vertebral arteries would increase the blood pressure in basilar artery. Meanwhile, missing communicating arteries in the circle of Willis, especially bilateral posterior communicating arteries absences, would significantly increase blood pressure in basilar artery. The unilateral absence of posterior communicating arteries would increase differences in blood flow between the left and right posterior cerebral arteries. InterpretationThis study provided a multi-scale modeling method and some preliminary results for helping understand the role of hemodynamics in occurrence and development of vertebrobasilar dolichoectasia.

Evaluation of neurosonology versus digital subtraction angiography in acute stroke patients

Stroke is one of the most common neurological disorders with a high incidence in Middle-eastern regions. We aimed to assess the diagnostic accuracy of neurovascular ultrasound to detect of cerebral artery stenosis compared to digital subtraction angiography (DSA) as a gold standard method. Eighty patients presenting with symptoms of cerebral ischemia were enrolled in the study. They were examined by cervical color Doppler ultrasound and TCCS to determine stenosis of extracranial and intracranial arteries, respectively. DSA was performed 24–48 h after the initial examination. The sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of neurovascular ultrasound in comparison to DSA were calculated. The agreement between the two methods was determined by kappa statistics. Eighty patients (60% male, 40% female) with a mean age of 61.32 ± 12.6 years were included. In 65% of patients, stenosis in carotid artery caused ischemic symptoms. We did not observe any stenosis in anterior cerebral artery, posterior cerebral artery and basilar artery in patients. The agreement between the neurovascular ultrasound and DSA in various arterial vessels was 0.9 for common carotid artery, 0.86 for internal carotid artery, 0.78 for middle cerebral artery, and 0.86 for vertebral artery. The sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and kappa value of the neurovascular ultrasound for detecting stenosis regarding the arterial segments were 84.8%, 81%, 92.6%, 65.4%, 83.8, and 0.71, respectively. In conclusion, the neurovascular ultrasound is a valuable, non-invasive, and repeatable method to investigate cerebral artery stenosis with high diagnostic accuracy.

Abstract P374: Dolichoectacic Features of Basilar Artery Serve an Imaging Surrogate of Branch Artery Disease in Patients With Pontine Infarcts

Background: The arterial pathology underlying recent small subcortical infarctions (historically known as lacunar stroke) is heterogenous and includes lipohyalinosis, branch artery atherosclerosis or embolism. Although the use of high-resolution imaging studies directed to vessel wall might be helpful in teasing out these different pathologies, more readily available imaging surrogates such as size or spatial characteristics of the ischemic lesion are used for this purpose in clinical practice. Herein, we determined the distribution of dolichoectacic features of basilar artery in patients presenting with pontine penetrator artery stroke with different underlying occlusive pathologies. Methods: The dolichoectacic features of basilar artery were retrospectively evaluated according to Smoker’s criteria (diameter: >4.5 mm, laterality: more lateral to the lateral margin of clivus or dorsum sellae, and height of bifurcation: at least at the level of third ventricular floor) on CT angiography in ischemic stroke patients with a single penetrator artery occlusion in the pons. Patients with basilar artery pathologies such stenosis, dissection, or apparent dolichoectasia were excluded. Ischemic lesions extending to the surface of pontine base on DWI were judged to be secondary to branch artery occlusion, rather than lipohyalinosis. Results: Out of 122 patients, 68 (56%) had at least one feature suggestive of basilar artery dolichoectasia. Patients with lateral deviation of basilar artery were more likely to harbor infarcts extending to pontine surface (69% vs. 50%); no such relationship was identified for other imaging markers of dolichoectasia. After adjustment for age, gender and vascular risk factors, lateral deviation of the basilar artery remained significantly associated with an infarct pattern suggestive of branch artery occlusion (OR=2.8, 95%CI 1.1-7.3; p=0.031). There was also a tendency for ischemic lesions to be located on the ipsilateral side of the lateral deviation (63%; p=0.081). Conclusion: Our findings highlight that lateral displacement of basilar artery, an imaging feature of basilar dolichoectasia, can be used as an additional surrogate marker of branch artery pathology in patients with pontine penetrator artery infarction.

Angioplasty and Stenting of Intracranial Arterial Stenosis in Perforator-Bearing Segments: A Comparison Between the Anterior and the Posterior Circulation.

Background and Purpose: Subgroup analysis of the SAMMPRIS trial showed a higher rate of periprocedural perforator strokes with the Wingspan stent in the basilar artery in patients with symptomatic intracranial atherosclerotic stenosis (ICAS). It remains unclear whether angioplasty (PTA) alone or in combination with other stent types (PTAS) will yield similar results in perforator-bearing segments of the anterior and posterior circulation.Methods: We retrospectively analyzed the periprocedural complication rate, long term outcome and stroke etiology in 59 consecutive patients with ICAS of the middle cerebral artery (79 treatments) and 67 patients with ICAS of the intracranial vertebral and basilar artery (76 treatments) treated with PTA or PTAS from 2007 to 2015 in a high-volume neuro-interventional center.Results: Periprocedural symptomatic ischemic strokes occurred significantly more often in patients with posterior vs. anterior ICAS treatment (14.5 vs. 5.1%, p = 0.048). During a mean follow-up period of 19 (±23.7) months, 5 recurrent ischemic and 2 hemorrhagic strokes (10.4%) occurred in the territory of the treated artery in posterior circulation compared to 2 ischemic strokes in the anterior circulation (3.4%, p = 0.549). Overall, significantly more patients treated for a posterior ICAS suffered a periprocedural or follow-up stroke [25% vs. 11.4%, p = 0.024]. Periprocedural ischemic strokes were predominantly perforator strokes (73.3%), while all ischemic strokes during follow-up were caused by distal embolization (57.1%) or delayed stent occlusion (42.9%). There was no difference between PTA alone and PTAS.Conclusion: The periprocedural and long-term symptomatic stroke rate was significantly higher in the treatment of perforator-bearing arteries in the posterior circulation. There was no difference between PTA alone or PTAS.

Significance of Raised Flow Velocity in Basilar Artery in Patients with Acute Ischemic Stroke: Focal Stenosis, Coexistent Stenosis, and Collateral Flow.

Increased cerebral blood flow velocity of basilar artery (BA) is common but often neglected. By using digital subtraction angiography (DSA) to detect intracranial large artery stenosis, we performed transcranial Doppler (TCD) to evaluate cerebral hemodynamic changes of stroke patients. Acute stroke patients with TCD-detected raised peak systolic velocity (PSV) in BA (≥100 cm/second) were recruited. Among 91 recruited patients, BA stenosis (>50%) was confirmed by using DSA in 29 patients (32%), among which 20 patients (70.0%) had coexistent internal carotid artery (ICA) and vertebral artery (VA) stenoses. Among patients without BA stenosis (n = 62, 68%), severe stenosis or occlusion of ICA was evaluated in 22 patients (22/62, 35.4%) and severe stenosis or occlusion of VA was detected in 22 patients (22/62, 35.4%). Among the values of PSV (120, 140, 160, and 180 cm/second) and the stenotic-to-prestenotic ratio (SPR) (1.5, 2.0, 2.5, and 3.0), 160 cm/second was found to show the highest predictive value (area under the receiver operator characteristic curve: .75, 95% CI: .65-.86), with a sensitivity of .70 and a specificity of .81. Apart from an intrinsic BA stenosis, high-grade steno-occlusion of ICA or VA may contribute a lot to induce an elevated flow velocity in BA. A higher value of cutoff point may increase the accuracy of diagnosing BA stenosis.

Cerebral hemodynamic changes at basilar artery in patients with obstructive sleep apnea syndrome. A case-control study

Obstructive sleep apnea syndrome (OSAS) is characterized in polysomnography by recurrent airflow obstruction during sleep. The underlying pathogenic mechanisms of neuropsychological and cerebrovascular events in patients with OSAS have not been clarified unequivocally. Case-control study to evaluate the cerebral vasomotor reactivity assessed by breath-holding maneuver at basilar artery in patients with OSAS compared to control subjects. The study included 76 patients with OSAS and 76 controls. Vascular risk factors (arterial hypertension, diabetes mellitus, hypercholesterolemia, smoking), age, gender, coronary, and peripheral arterial diseases were similar in both groups. Patients with OSAS had breath-holding test values (31.9 ± 13.35%) lower than controls (39.06 ± 13.16%), (P = 0.001). Patients with OSAS had higher systolic and diastolic blood pressure both basal and apnea and also a higher basal heart rate. Altered cerebral hemodynamics together with increased blood pressure values in patients with OSAS may play a role in the association between this disease and the development of cerebrovascular events. This implies that this disease should be identified through guide symptoms such as snoring, sleep apnea, and daytime sleepiness in all patients who consult for these symptoms to reduce the number of cerebrovascular events.

Transcranial Doppler ultrasonography of the basilar artery in patients with retrograde vertebral artery flow

Reversal of flow in the extracranial vertebral artery secondary to a proximal subclavian/innominate artery stenosis or occlusion is a frequent finding during carotid duplex ultrasonography. The characteristics of basilar artery flow are not well defined in these patients. The objective of this study is to evaluate basilar artery flow in patients with retrograde vertebral artery flow. From a transforaminal vice transforamen approach with the patient seated, pulsed Doppler scan spectral waveforms were obtained from the distal segment of each vertebral artery (depths of 66 mm and 70 mm) and throughout the basilar artery (depths of 80 mm up to 116 mm). The direction of flow and the peak flow velocity were recorded at each location. In the subset of patients with antegrade flow, we initiated a 5-minute period of arm ischemia (produced by brachial blood pressure cuff inflated to a suprasystolic pressure) and compared flow direction to baseline. Twenty-five patients with retrograde vertebral artery flow on carotid duplex ultrasonography underwent transcranial Doppler (TCD) ultrasonography scan of the distal vertebral arteries and the basilar artery. There were 10 males (58-85-years-old; mean 70.7 years) and 15 females (47-85-years-old; mean 66.0 years). An additional 11 patients who had normal vertebral flow underwent TCD and served as a control group. Nineteen patients (76%) demonstrated antegrade basilar artery flow at rest. Six patients (24%) demonstrated abnormal basilar artery flow at rest. Five had complete reversal of flow; one had intermittent flow reversal which became retrograde throughout the cardiac cycle following a period of arm ischemia ipsilateral to the patient's retrograde vertebral artery flow. No patient with retrograde vertebral artery flow and antegrade basilar artery flow at rest demonstrated a change in basilar artery peak velocity or direction of flow following arm ischemia. Less than 25% of patients with retrograde vertebral artery flow on carotid duplex ultrasonography scan demonstrated a corresponding reversal of flow in the basilar artery. The vast majority of patients do not develop flow reversal in the basilar artery. Provocative maneuvers to increase collateral flow to the arm ipsilateral to retrograde vertebral artery flow did not appear to alter basilar artery flow velocity or direction of flow. Transcranial Doppler ultrasonography is indicated in patients with retrograde vertebral artery flow to document basilar artery flow, especially prior to intervention in patients with symptoms suggestive of posterior cerebral circulation insufficiency.

Incidental aneurysms of aorta and basilar artery in patients with coronary artery ectasia. A magnetic resonance angiography study

Objective — Incidental intracranial aneurysms have been revealed in 0.5-1% of adult patients undergoing cerebral angiography, while only 8% of those aneurysms are located in the basilar artery.Those aneurysms running usually symptomless, may lead to life-threatening situations due to rupture. Intracranial aneurysms could co-exist with abdominal aneurysms. Another dilating arterial lesion, coronary artery ectasia was linked in previous studies with aneurysms of the abdominal aorta.The aim of the present study is to investigate the coexistence of coronary artery ectasia with other aneurysms since dilating arterial lesions seem to share a similar pathogenesis, a thin or absent media of the arterial wall.Methods and results — Ten consecutive patients with coronary artery ectasia after coronary angiography underwent magnetic angiography (MRA) of the brain, thoracic and abdominal aorta. Three incidental aneurysms were revealed: one intracranial aneurysm located in the basilar artery, one extended thoracic/abdominal aneurysm and one abdominal aneurysm. Embolism was used for the management of the basilar artery aneurysm while the extended aneurysm of the descending thoracic and abdominal aorta was surgically repaired in part.Conclusions – Whether our results are just a coincidence or they announce a common pathogenesis is a subject of further screening studies of the population. Nevertheless, a high index of suspicion is expected for patients with coronary ectasia about the presence of other vascular defects at different locations, especially when non-typical symptoms are mentioned.

Direct surgery for major artery aneurysm associated with Moyamoya disease

Moyamoya disease is often accompanied by intracranial major artery aneurysms in the posterior circulation which acts as collateral channels in place of the stenotic internal carotid arteries. These major artery aneurysms are considered to have high risk of enlargement and rupture due to increased hemodynamic stress. Direct surgical intervention has been recommended for the treatment of these aneurysms, but the direct approach to them is often difficult due to interference by intertwined abnormal vessels. We have performed direct surgery for seven major artery aneurysms in five patients with Moyamoya disease. Of these three aneurysms located in the anterior circulation were successfully clipped via pterional or interhemispheric approach. Of four posterior circulation aneurysms (two at the junction of the basilar artery and the superior cerebellar artery and two at the P1–P2 junction of the posterior cerebral artery), one was approached via pterional route because collateral vessels in the basal cistern was judged not to be rich on angiograms. However, the operative field was interfered by abundant fragile collateral vessels and it was difficult to reach the distal portion of the basilar artery. In contrast, in the other three cases in which the subtemporal approach was employed, there weren't any problems in exposures of the aneurysms. Our experiences indicate that subtemporal approach is superior than the pterional approach to reach the distal portion of the basilar artery in patients with Moyamoya disease.

Angiographic Morphology of the Posterior Communicating Artery and Basilar Artery in Patients with ICA-PComA Aneurysm

The relationships between the angiographic morphology of the posterior communicating artery (PComA) and the basilar artery (BA) and saccular aneurysms at the internal carotid artery (ICA)-PComA junction were evaluated in 23 patients with ICA-PComA aneurysm and 46 controls. No significant differences were found in the height of the basilar top, the dislocation and inner diameter of the BA, and the distance between the basilar top and the ICA-PComA junction. However, the angle between the PComA and C2 portion of the ICA was larger and the PComA straighter in ICA-PComA aneurysm patients. Tension in the PComA and mechanical damage to the divergent angle of the PComA are probably important factors in the development of ICA-PComA aneurysms.