Basilar Artery Lesions Research Articles

Basilar Artery Tortuosity Increases the Risk of Persistent Dizziness and Unsteadiness After Posterior Circulation Infarction.

Basilar artery (BA) tortuosity is closely associated with posterior circulation infarction (PCI) and dizziness/unsteadiness. This study aims to determine the relationship between BA tortuosity and the outcome of dizziness and unsteadiness in PCI patients. This study prospectively recruited PCI patients presenting with dizziness and unsteadiness. BA tortuosity was diagnosed based on Smoker's criteria. The BA tortuosity index (BATI) was measured from magnetic resonance angiography (MRA) images. Posterior circulation was divided into proximal (medulla oblongata and posterior inferior cerebellar), middle, and distal territories. Symptoms, risk of falls, and quality of life were followed up in 3 months after stroke. Logistic regression was used to identify possible factors associated with the persistence of dizziness and unsteadiness. Among 182 PCI patients presenting with dizziness and unsteadiness, 97 (53.3%) had BA tortuosity, including 19 (10.4%) with moderate-to-severe BA tortuosity. At the 3-month follow-up, 58 (31.9%) patients continued to experience dizziness and unsteadiness, with significantly decreased quality of life and a high risk of falls. Binary logistic regression analysis identified moderate-to-severe BA tortuosity (OR, 4.474; 95% CI, 1.591-12.579; p = 0.004) and lesions involving the proximal posterior circulation territory (OR, 2.146; 95% CI, 1.097-4.199; p = 0.026) as risk factors for persistent dizziness and unsteadiness after PCI, while thrombolysis (OR, 0.280; 95% CI, 0.079-0.992; p = 0.049) as a protective factor. BATI (OR, 1.072; 95% CI, 1.028-1.119; p = 0.001) was also independently associated with dizziness and unsteadiness after PCI. Prominent BA tortuosity increases the risk of persistent dizziness and unsteadiness after PCI, leading to a high risk of falls and decreased quality of life. This warrants more attention in clinical practice.

Comparison of the clinical value of transcranial Doppler ultrasound and computed tomography angiography for diagnosing ischemic cerebrovascular disease.

ObjectiveTo compare the clinical value of transcranial Doppler (TCD) ultrasound and computed tomography angiography (CTA) for diagnosing ischemic cerebrovascular disease.MethodsA retrospective clinical study was conducted in 142 patients with ischemic cerebrovascular disease who were initially diagnosed by digital subtraction angiography. Under the single-blind condition, the patients were diagnosed by using TCD ultrasound and CTA independently. The accuracy of these two methods was compared.ResultsThe accuracy of diagnosing bilateral middle cerebral artery, bilateral vertebral artery and bilateral internal carotid artery lesions with a TCD examination was significantly higher than that with a CTA examination. There were no significant differences in the accuracy of diagnosing bilateral anterior cerebral artery, bilateral posterior cerebral artery or basilar artery lesions between TCD ultrasound and CTA. The accuracy of diagnosing all cerebral arterial ischemic lesions was significantly higher with a TCD examination (87.39%) than with a CTA examination (69.75%). The accuracy of diagnosing all cerebral arteries that cause ischemic encephalopathy (cerebrovascular + cervical blood vessels) was significantly higher with a TCD examination (88.03%) than with a CTA examination (69.01%).ConclusionsTCD ultrasound has several advantages over CTA. Therefore, TCD ultrasound is better for diagnosing ischemic encephalopathy than CTA.

Long-Term Characteristics of De Novo Bleb Formation at the Aneurysm Neck After Coil Embolization in Unruptured Cerebral Aneurysms

De novo bleb formation at the aneurysm neck after coil embolization of unruptured intracranial aneurysms is a rarely observed type of recurrence. The aim of this study was to elucidate the clinical characteristics of recurrent aneurysms in the long-term period. Between January 2002 and December 2015, 290 unruptured intracranial aneurysms were treated with coil embolization at our institution. Patients who underwent retreatment due to aneurysm recurrence were divided into 2 patterns of recanalization: de novo bleb formation at the neck of a coiled sac (type DNV) and an enlarged residual cavity without de novo bleb formation (type non-DNV). Twenty-seven patients with aneurysms (9.3%) underwent retreatment (type DNV, 7; type non-DNV, 20). The initial aneurysm size of type DNV aneurysms was significantly smaller than that of type non-DNV (6.1 ± 2.2 mm vs. 10.1 ± 3.6 mm; P < 0.01), and time to retreatment in type DNV was significantly longer than that in type non-DNV (9.4 ± 5.3 years vs. 2.0 ± 2.0 years; P < 0.01). Two type DNV basilar artery (BA) aneurysms ruptured after a few years; however, the other type DNV aneurysms, including 4 anterior circulation aneurysms (including the internal carotid artery), were observed to grow gradually without rupture for >10 years until retreatment. De novo bleb formation at the neck of a coiled sac emerges with insidious growth during long-term follow-up. Constant caution should be exercised, even in cases of small- and medium-sized anterior circulation aneurysms. A risk of rupture risk may be anticipated, especially in BA lesions.

Posterior Circulation Moyamoya Disease versus Primitive Vertebral-Basilar Artery System Moyamoya Disease: New Classification of Moyamoya Disease from the Perspective of Embryology

Moyamoya disease (MMD) is a chronic cerebrovascular disorder with little known etiology. We aim to propose a new classification system for MMD from the perspective of embryology. MMD patients' digital subtraction angiograms were retrospectively analyzed. Every angiogram was analyzed to find the abnormal vessels and from which part of the posterior cerebral artery (PCA) the lesions begin. In 262 MMD cases, 32 pediatric patients had PCA involvement, of which 17 were male and 15 were female; 68 adults had PCA involvement, of which 33 were male and 35 were female. The initially affected part of the PCA was compared between sexes and between pediatric and adult patients, and the findings are not statistically significant (P= 0.233, P= 0.855, P= 0.343, respectively). However, of the 100 cases with PCA involvement, only 4 had the lesions begin from the first part of the PCA, and all of the 4 cases had the basilar artery lesions. All the other 96 cases had the lesions begin from the second part of the PCA or from the posterior communication artery, which is derived from the caudal ramus of the primitive intracarotid artery, leaving the first part of the PCA and basilar artery excluded from affection. MMD should be classified into primitive intracarotid artery system-involved type and primitive vertebral basilar artery system-involved type. The reason that the vertebral basilar artery is so rarely involved in MMD might be because of its late development in the brain.

Endovascular treatment of tandem vascular occlusions in acute ischemic stroke

Background and purposeTandem vascular occlusions are an important cause of acute ischemic stroke (AIS) and present unique treatment challenges. We report our experience of managing a subset of AIS patients...

Anatomical variations in pneumatization of the anterior clinoid process

An anterior clinoidectomy can provide enormous benefits, facilitating the management of paraclinoid and upper basilar artery lesions, but it also carries the potential risk of cerebrospinal fluid leaks. The aim of this study was to assess the variation in the pneumatization of the anterior clinoid process (ACP) in an attempt to reduce the complications associated with an anterior clinoidectomy. The authors analyzed the anatomical variations in the pneumatization of the ACP and optical strut (OS) in 600 sides of 300 consecutive patients by using multidetector-row computed tomography (CT). Computed tomography scans with a 0.5-mm thickness were obtained, and coronal and sagittal reconstructions of the images were displayed in all cases. Pneumatization of the ACP was found in 9.2% of all sides. The origin of pneumatization was the sphenoid sinus in 81.8% of all the sides, the ethmoid sinus in 10.9%, and both of these sinuses in 7.3%. Pneumatized patterns were divided into three groups according to the route: 74.5% were Type I, in which pneumatization occurred via the OS; 14.5% were Type II, pneumatization via the anterior root (AR); and 10.9% were Type III, pneumatization via both the OS and the AR. The origin of pneumatization and the pneumatization pattern showed statistical dependence (p < 0.001). Pneumatization of the OS beyond its narrowest point was found in 6.8% of all sides. An awareness of the different variations in pneumatization can prevent destruction of the mucous membrane and facilitate orientation during reconstruction with cranialization. During an anterior clinoidectomy, preoperative CT assessments are necessary to evaluate pneumatization of the ACP.

Stenting of vertebrobasilar arteries in symptomatic atherosclerotic disease and acute occlusion: Case series and review of the literature

Two of three patients with vertebrobasilar stroke harbor a stenosis of the vertebral or basilar arteries. The best treatment for secondary prophylaxis in vertebrobasilar occlusive disease has not been defined. In patients with high-grade stenoses, and especially those refractory to medication, stenting offers the chance to restore normal flow and prevent major strokes. We provide data regarding outcome and complications on 20 consecutive patients who underwent vertebrobasilar stenting at our institution (9 V0, 2V3, 5 V4, and 4 basilar artery lesions). Furthermore, we provide a comprehensive overview of the literature on >600 cases of vertebrobasilar stenting, including all published cases up to 2005. Primary interventional success was achieved in all cases, with a mean residual stenosis of 3% +/- 4% in V0, 5% +/- 4% in V3/4, and 7% +/- 3% in basilar artery lesions. No peri-interventional neurologic complications and no transient ischemic attack or stroke at follow-up were noted in patients with vertebral ostial lesions, whereas two transient and three permanent clinical deteriorations occurred in patients with V4 or basilar artery lesions, some of which had presented with acute stroke. Patency rate was 100% at the last examination. According to published data on proximal vertebral artery stenting, mortality is 0.3%, the rate of neurologic complications is 5.5%, and the risk of posterior stroke at follow-up is 0.7%. Interventions for distal vertebral or basilar artery disease carry a 3.2% mortality risk, a 17.3% risk for neurologic complications and a 2% risk for stroke at follow-up. Stenting of the vertebral origin can be performed safely and with a low rate of cerebral ischemic events at follow-up, although restenosis may occur. Larger comparative trials are needed. Treatment decisions in distal vertebrobasilar disease have been made on an individual basis.

Risk factors for occlusive lesions of intracranial arteries in stroke‐free Japanese

The aim of this study was to identify relevant risk factors for occlusive lesions of the intracranial arteries in stroke-free population. The subjects of this study were 425 patients without a history of stroke or transient ischemic attack and without any abnormality on a neurological examination who consecutively visited a neurology clinic between January 1994 and June 2001 requesting medical evaluation for possible cerebrovascular diseases. Subjects included 245 men and 180 women ranging in age from 33 to 89 years (mean+/-SD=64.0+/-10.0 years). We performed cervical and intracranial magnetic resonance angiography (MRA) in all subjects. Using a validated rating scheme of MRA for occlusive lesions, we evaluated the degree of stenoses in the extracranial portion of the internal carotid artery (ICA) and the intracranial arteries including the intracranial portion of the ICA, middle cerebral artery (MCA) stem, intracranial portion of the vertebral artery (VA), and basilar artery (BA). More than 25% stenoses were regarded as significant lesions in this study. Multiple logistic regression analyses showed that significant and independent predictors for extracranial ICA lesions were age, hyperlipidemia, and ischemic heart disease (IHD), those for intracranial ICA lesions were age, hypertension, diabetes mellitus, and IHD, those for MCA lesions were age and hypertension, those for intracranial VA lesions were hyperlipidemia and IHD, and those for BA lesions were hypertension and diabetes mellitus. The present study suggested that atherosclerosis of the intracranial VA was related to hyperlipidemia and IHD as was the case for the extracranial carotid artery, whilst atherosclerosis of other sites of intracranial arteries was associated with hypertension and diabetes mellitus in stroke-free Japanese.

New England Medical Center Posterior Circulation Stroke Registry II. Vascular Lesions

Among 407 New England Medical Center Posterior Circulation Registry (NEMC-PCR) patients, the extracranial (ECVA) and intracranial vertebral arteries (ICVA) were the commonest sites of severe occlusive disease followed by the basilar artery (BA). Severe occlusive lesions were found in >1 large artery in 148 patients; 134 had unilateral or bilateral severe disease at one arterial location. Single arterial site occlusive disease occurred most often in the ECVA (52 patients, 15 bilateral) followed by the ICVA (40 patients, 12 bilateral) and the BA (46 patients). Involvement of the ICVAs and the BA was very common and some patients also had ECVA lesions. Hypertension, smoking, and coronary and peripheral vascular disease were most prevalent in patients with extracranial disease while diabetes and hyperlipidemia were more common when occlusive lesions were only intracranial. Intra-arterial embolism was the most common mechanism of brain infarction in patients with ECVA and ICVA occlusive disease. ICVA occlusive lesions infrequently caused infarction limited to the proximal territory (medulla and posterior inferior cerebellum). BA lesions most often caused infarcts limited to the middle posterior circulation territory (pons and anterior inferior cerebellum). Posterior cerebral artery occlusive lesions were predominantly embolic. Penetrating artery disease caused mostly pontine and thalamic infarcts. Prognosis was poorest in patients with BA disease. The best prognosis surprisingly was in patients who had multiple arterial occlusive lesions; they often had position-sensitive transient ischemic attacks during months or years.

Safety and short-term results of stent-assisted angioplasty for the treatment of intracranial arterial stenosis

To evaluate the safety and short-term outcome of endovascular stent-assisted angioplasty for the treatment of intracranial arterial stenosis. Angioplasty and stent placement were administered to treat 46 patients with lesions of atherosclerotic intracranial stenosis, including 16 lesions of basilar artery, 12 of vertebral artery, 13 of internal carotid artery and 9 of middle cerebral artery. Technical success was achieved in 49 of 50 vessels (98%), with no procedure-related death or cerebral ischemic attack. Extracranial internal carotid artery dissection occurred in 1 patient and was successfully treated with a self-expand stent. One patient had subarachnoid hemorrhage because of perforation by microwire with no permanent neurologic deficit, and another 2 patients had groin hematoma. Angiographic examination immediately after stenting revealed that the stenosis rate was significantly reduced (72.4% +/- 12.3% vs 10.6% +/- 7.8%). There was no cerebral ischemic attack in the 37 patients who were clinically followed up (6 - 18 months, mean of 8.5 months). Angioplasty and stenting for the treatment of intracranial stenosis is safe and feasible, and it may be favorable for decreasing the incidence of ischemic attack.

Urgent endovascular revascularization for symptomatic intracranial atherosclerotic stenosis

Endovascular revascularization for intracranial atherosclerotic stenoses is being increasingly performed at major medical centers and has been reported to be technically feasible and safe. The authors report their experience with patients who underwent such a procedure for impending stroke and neurologic instability. All 18 patients (21 intracranial lesions) treated between 1997 and 2002 at the authors' institution with endovascular revascularization were retrospectively reviewed. Each patient had failed maximal medical therapy and was thought to be at high risk for an imminent stroke. Endovascular revascularization was performed on eight distal internal carotid artery lesions, six middle cerebral artery lesions, four intracranial vertebral artery lesions, and three basilar artery lesions. Recanalization was complete in 5 arteries (Thrombolysis in Myocardial Infarction [TIMI] Grade III), partial in 14 arteries (TIMI Grade II), and complete occlusion (TIMI 0) developed in 1 artery. In a patient with a tight basilar stenosis, no angioplasty could be performed because of the inability to cross the stenosis with the guidewire. Major periprocedural complications occurred in 9 (50%) patients: intracranial hemorrhage in 3 (17%), disabling ischemic stroke in 2 (11%), and major extracranial hemorrhage in 4 (22%). Three patients died: one from intracerebral hemorrhage and two from cardiorespiratory failure. Endovascular revascularization of intracranial vessels is technically feasible and may be performed successfully. However, periprocedural complication and fatality rates in neurologically unstable patients are high. The results suggest that patient selection, procedure timing, and periprocedural medical management are critical factors to reduce periprocedural morbidity and mortality.

Lateral suboccipital approach and utility of lateral arched skin incision in the treatment of vertebral and lower basilar artery aneurysm

The lateral suboccipital approach with a lateral arched skin incision is the simplest and least invasive surgical treatment for cerebrovascular lesions involving the vertebral and lower basilar artery. The merit of the lateral arched skin incision is stressed because it eliminates the need for extensive craniotomy approaches to be used in the treatment of vertebral and lower basilar artery lesions. Unnecessary extensive craniotomy should be avoided wherever possible in routine neurosurgical practice.

Basilar Artery Occlusive Disease in the New England Medical Center Posterior Circulation Stroke Registry

P57 Most reports on basilar artery (BA) occlusive disease have retrospectively described isolated cases or small series of patients, focusing mainly on clinicoanatomical correlations. To assess the stroke mechanisms, etiologies, clinical and vascular features, and outcome of BA occlusive disease, we analyzed 76 patients (52 men, 24 women; mean age: 62.1 yrs; range: 5 - 87 yrs) prospectively collected in the New England Medical Center Posterior Circulation Stroke Registry between November 1986 and February 1997, with a diagnosis of moderate (50–70%) to severe (&gt;70%) BA stenosis or occlusion. Vascular imaging was done by TCD, catheter angiography or MRA. BA stenosis was found in 51 (67.1%) patients, while 25 (32.9%) had BA occlusion. Most patients (60.5%) had involvement of the mid-portion of the BA. In 44.7% of patients, the occlusive disease was intrinsic to the BA, in 43.4% BA involvement was part of extensive atherosclerosis in the posterior circulation, and 11.8% of patients had embolism to the BA from the heart or proximal arteries. Fifty-two patients (68.4%) had strokes, half preceded by TIAs. The remaining 24 patients presented with TIAs only. The average duration of TIAs was 3.7 months, when excluding 4 patients whose TIAs lasted over 8 yrs. When an infarct was present, the middle posterior intracranial territory including the pons and the anteroinferior cerebellum was most often involved (73.1%). The etiology of the BA lesions was atherothrombotic in 77.6% and the mechanism presumed hemodynamic in 73.7%. Hypertension (64.5%), hyperlipidemia (40.8%) and coronary artery disease (35.5%) were the most frequent risk factors. Among the 9 patients without risk factors, 3 had BA dissections and 2 had basilar migraine. Of patients with a BA stenosis, 50% had no deficits at follow-up, whereas 75% of BA occlusions lead to disability. Embolism to the BA had severe outcome, with major disability or death occurring in 77.8% of patients. The outcome was best in the patients with diffuse atherosclerotic disease. Our data shows that studying the clinical and vascular features helps understand the mechanism, etiology and determine outcome in BA occlusive disease.

Angioplasty of Acute Occluded Cerebral Arteries

22 cases of stenosed or occluded cerebral arteries were treated by percutaneous transluminal angioplasty (PTA) in acute stage. There were 10 internal carotid lesions, 4 middle cerebral artery lesions, 5 intracranial vertebral artery lesions, and 3 basilar artery lesions. 14 cases were treated for residual stenosis after recanalization using urokinase. Successful dilatation (over 50%) was achieved in 16 cases (73%).3 lesions were inaccessible due to atherosclerotic change. There were no major complications. Restenosis was observed in 4 internal carotid lesions and 1 middle cerebral lesion. 7 (50%) cases with internal carotid lesions and 5 (63%) cases with vertebrobasilar lesions returned to their previous life. The results suggest that PTA in acute stage is feasible for occlusive disease of cerebral arteries.