Distal Vertebral Artery Research Articles

“Double-Barrel” Stent Reconstruction of a Symptomatic Fusiform Basilar Artery Aneurysm: Case Report

Giant fusiform aneurysms of the basilar artery are associated with a high rate of morbidity and mortality. Treatment of these lesions can be difficult, especially when there are poor anatomic collaterals such as posterior communicating arteries. These lesions often have no acceptable treatment. The authors present a case of a patient with a symptomatic, fusiform basilar artery aneurysm successfully treated with a side-by-side (double-barrel), telescoping stent construct. A 56-year-old man presented with chief concerns of dysarthria and left-sided hemiparesis. MRI and conventional catheter-based angiography revealed a dolichoectatic basilar artery with 3 large fusiform aneurysms throughout its length. Flow through the patient's aneurysm was successfully reduced with a side-by-side stent construct and coiling of the proximal aneurysm dilation. The patient experienced stabilization of his ischemic events and neurologic recovery. A total of 6 Neurform-2 4.5 × 30-mm stents were navigated and positioned from the proximal posterior cerebral arteries to the distal vertebral arteries in a side-by-side (double-barrel), telescoping manner. These were deployed simultaneously by 2 operators to oppose the stent struts as well as the arterial wall. Next, the proximal aneurysmal dilation was coiled to near occlusion. Successful flow redirection and aneurysm thrombosis was observed. A novel, endovascular stenting technique for successfully treating symptomatic, giant basilar artery aneurysms is presented. This patient at 4 months was living independently with no further neurologic events or decline.

Vertebral artery stenting in a patient with reversed flow in the anterior spinal artery

We present neuroimages for a patient in a locked-in state with reversed flow in the anterior spinal artery as a result of bilateral distal vertebral artery occlusion. Following vertebral artery...

Rotational vertebral artery syndrome due to compression of nondominant vertebral artery terminating in posterior inferior cerebellar artery

Rotational vertebral artery syndrome (RVAS) is characterized by recurrent attacks of paroxysmal vertigo, nystagmus, and ataxia induced by head rotation. We report on a patient who developed atypical RVAS due to compression of the vertebral artery (VA) terminating in the posterior inferior cerebellar artery (PICA). A 59-year-old man suffered from vertigo and nystagmus induced by leftward head rotation and oculography showed right beating horizontal-torsional and downbeat nystagmus. Cerebral angiography showed hypoplastic right VA terminating in PICA without connection to the basilar artery. The basilar artery received its flow from the left VA only and branched out both anterior inferior cerebellar arteries. Cerebral angiography revealed a complete occlusion of the right distal VA at the level of the C1-2 junction when the head was rotated to a leftward position. In contrast, the blood flow through the left vertebral and basilar arteries remained intact while turning the head to either side. The hemodynamic compromise observed in our patient with RVAS indicates that isolated vertigo and nystagmus may occur due to transient ischemia of the inferior cerebellum or lateral medulla.

A Case of Ipsilateral Hemiparesis in Lateral Medullary Infarction: As a Warning Sign of Acute Progression of Vertebral Artery Thrombosis

A 70-year-old man presented with acute dysarthria and dizziness. He denied any history of trauma or cervical manipulations within several weeks before symptom onset. We could make a presumptive diagnosis of left Wallenberg syndrome through the results of neurologic examination, which include left limb ataxia, alternating hyp(o)esthesia, spontaneous nystagmus to right side, and left side Honer’s syndrome. Initial diffusion weighted imaging performed at admission showed small and discrete high signal lesions in left lateral medulla, left cerebellar hemisphere, and bilateral occipital areas. Contrast enhanced MRA demonstrated a fi lling defect in long segment of distal left vertebral artery. On 4th days after symptom onset, the patient developed a severe form of ipsilateral hemiparesis. Follow-up brain MRI showed a downward extension of the initial ischemic lesion in upper medulla to upper cervical region. This case suggests that a severe form of ipsilateral hemiparesis may be complicated in the clinical setting of acute lateral medullary infarction with vertebral artery occlusion. (Korean J Stroke 2011;13:137-139)

Medial medullary infarction with occlusion of distal vertebral arteryand basilar artery: A case report

症例は64歳の男性で，散歩中，突然の右片麻痺と構音障害を自覚し，当院へ緊急入院となった．頭部CTでは明らかな異常所見を指摘できず，MRI拡散強調画像を行ったところ，延髄左傍正中部に淡い高信号域を認めた．発症6日後に行ったMRI拡散強調画像では，延髄左傍正中部に強い高信号域を認めた．発症7日後の脳血管撮影では，左遠位椎骨動脈と脳底動脈で閉塞を認め，これがMMIの原因と考えられた．発症14日後に行ったbasi-parallel anatomical scanning MR imaging （BPAS-MRI）では，左遠位椎骨動脈に狭小化を認めた．MMIの原因として，遠位椎骨動脈の動脈硬化が重要で，多くはbranch occlusionの様式で梗塞を発症するといわれている．われわれの経験から，MMIの症例においてBPAS-MRIを行うことは，MMIの発症機序の推定に有用であることが示唆された．

Successful interdisciplinary management of the misdeployment of two self-expanding stents into the internal carotid artery: a case report

IntroductionWith the widespread use of carotid artery stenting, previously unknown technical mistakes of this treatment modality are now being encountered. There are multiple strategies for the treatment of in-stent restenosis. With regard to surgical management, endarterectomy and patch plasty are favored. To the best of our knowledge, this report is the first description of a complete stent removal by the eversion technique.Case presentationWe report the case of a 63-year-old Caucasian man with misdeployment of two stents into his stenotic proximal internal carotid artery, resulting in a high-grade mechanical obstruction of the internal carotid artery lumen. With the contralateral internal carotid artery already occluded and associated stenoses of both proximal and distal vertebral arteries, an interdisciplinary therapeutic concept was applied. Bilateral balloon angioplasty and stenting of the proximal and distal stenotic vertebral arteries were carried out to provide sufficient posterior collateral blood flow, followed by successful surgical stentectomy and carotid endarterectomy using the eversion technique. Duplex scanning and neurological assessments were normal over a 12-month follow-up period.ConclusionsInterdisciplinary treatment is a recommended option to protect patients from further impairment. Further evaluation in larger studies is highly recommended.

Radiologic Importance of a High-Resistive Vertebral Artery Doppler Waveform on Carotid Duplex Ultrasonography

The appearance of the vertebral artery (VA) waveform on a pulsed Doppler examination performed during standard carotid duplex ultrasonography (CDU) may suggest vertebrobasilar disease. We sought to determine the radiographic importance of high-resistive (HR) pulsed Doppler VA waveforms seen on CDU. The Noninvasive Vascular Laboratory database was queried for CDU studies noting the HR VA Doppler signal. Studies with unilateral or bilateral HR and antegrade VA waveforms with correlative neuroimaging studies within 60 days were included. Imaging reports were reviewed to determine the following: (1) a normal VA; (2) at least moderate distal VA or basilar artery (BA) stenosis, occlusion, or dissection; (3) a congenitally diminutive VA; or (4) other abnormalities. Of 1338 studies with 1 or more HR VA waveforms, 79 studies met all inclusion criteria (n = 157 arteries) and had adequate correlative neuroimaging. There were 90 HR VAs, and HR waveforms were equally distributed between right and left sides. The mean peak systolic velocity of HR versus low-resistive (LR) VAs was 51.7 versus 63.6 cm/s (P = .04); the mean end-diastolic velocity of HR versus LR VAs was 4.6 versus 17.3 cm/s (P < .001); and the resistive index of HR versus LR VAs was 0.92 versus 0.73 (P < .001). Of all HR VAs, 18.9% were normal; 38.9% had distal vertebrobasilar stenosis or occlusion; 35.6% were congenitally diminutive; and 6.7% had other abnormalities (proximal stenosis, excessive tortuosity, fibromuscular dysplasia, and BA hypoplasia). The finding of an HR spectral Doppler signal in the VA was associated with major vertebrobasilar disease (46% of cases) and should prompt additional neuroimaging in the appropriate clinical situation.

P-017 ‘Double barrel’ stent reconstruction of a symptomatic fusiform basilar artery aneurysm

Objective and importanceGiant fusiform aneurysms of the basilar artery are associated with a high rate of morbidity and mortality. Treatment of these lesions can be difficult especially when there are...

Lethal giant cell arteritis with multiple ischemic strokes despite aggressive immunosuppressive therapy

Two patients with giant cell arteritis (GCA) had a malignant course despite aggressive immunosuppressive therapy. A 63-year-old woman presented with symptoms of headache, jaw claudication, scalp paresthesia, and visual disturbances. A temporal artery biopsy showed GCA. While on prednisone, she suffered ischemic strokes, and serial cerebral angiograms demonstrated bilateral, severe and progressive narrowing of distal vertebral and internal carotid arteries. Despite escalating immunosuppressive therapies, she suffered more infarcts and eventually died. Postmortem examination of arteries showed no active inflammation. A 65-year-old man presented with extrapyramidal symptoms though no symptoms typical of GCA. Imaging showed multiple ischemic strokes. Because serial angiograms demonstrated findings similar to the first patient, he underwent temporal artery biopsy that showed GCA. He died 7 months after his presentation with complications of aggressive immunosuppressive therapy. These two patients confirm that GCA can follow a lethal course despite escalating immunosuppressive therapies. Our two patients were unique in that eventually both anterior and posterior circulations were involved bilaterally in a characteristic location where the arteries penetrate the dura. This pattern should always raise the possibility of GCA and, if confirmed, should prompt aggressive immunosuppressive therapy. The dismal outcomes despite this approach may suggest a non-inflammatory arteriopathy, as seen on necropsy in one of our patients. Such an arteriopathy may require novel therapies to be considered for this severe variant of GCA.

Dissection of the Distal Vertebral Artery Treated by Modified Parent Artery Trapping and a Contralateral Stent Barricade

Endovascular trapping is the preferred treatment method for a vertebral dissecting aneurysm. We describe a case of ruptured dissecting aneurysms located just proximal to the vertebrobasilar junction treated by trapping the dissecting segment and barricading the basilar artery with a stent to protect against coil protrusion. Modified parent artery trapping with a stent barricade allows preservation of the adjoining confluent zone or side branch during endovascular trapping of the vertebral dissection.

Cerebellar Infarction Caused by Primary Central Nervous System Angiitis of Childhood: Case Report

Cerebellar infarction of childhood is rare, and is difficult in pathological diagnosis. We describe a case of radiographically diagnosed primary central nervous system angiitis of childhood. A 7-year-old boy experienced dizziness and headache persisting for 7 days. Diffusion-weighted images of magnetic resonance (MR) showed high signals in the left cerebellar hemisphere and vermis. The MR angiogram (MRA) findings were normal. A conventional angiogram demonstrated severe stenoses and occlusions at distal portion of left posterior inferior cerebellar artery, and irregularity in the wall of the cervical portion of the left vertebral artery (VA). Although he recovered without any neurologic deficits, an angiogram 3 months after admission showed occlusion at the cervical portion of left VA and filling of the distal VA with collateral arteries from the deep cervical artery. He was doing well, with no additional changes demonstrated on MRA, 12 months after the onset. Although MRA can detect abnormality within the proximal intracranial vessels, angiography is essential, especially in cases with distal stenoses. Repeated angiography in primary central nervous system angiitis of childhood is necessary at least 3 months after the onset, even if the patient has no symptom.

Ischemic stroke patterns and hemodynamic features in patients with small vertebrobasilar artery

Background To determine the role of small vertebrobasilar artery (SVBA) in patients with posterior circulation stroke (PCS), we evaluated the ischemic patterns, collateral features, and stroke mechanisms in PCS patients with SVBA. Methods Ischemic findings on magnetic resonance (MR) imaging were correlated with 3D time-of-flight/contrast-enhanced MR angiography and/or catheter angiography in 18 patients (mean age, 68.0 ± 11.8 years; 9 males). SVBA (lumen diameter of < 3 mm) was compared with stenotic normal-sized VBA (NVBA) in 14 PCS patients. Results Ischemic lesions were predominantly observed in the cerebellum and/or medulla (vertebral artery (VA) territory). All subjects had fetal posterior circulation (FPC) from the internal carotid artery to the posterior cerebral artery. Sixteen patients (88.9%) had distal or diffuse VA stenosis/occlusion. In 14 patients (77.8%), long circumferential artery (LCA) was prominently observed. In atherothrombotic patients, infratentorial PCS might occur following artery-to-artery embolism from the low-flowed or stenotic VA to LCA. Ischemic patterns between subjects with and without VA disease were almost similar. As the degree of VA disease increased, the frequency of LCA prominence showed an increased tendency ( P = 0.003). Relatively small, scattered infarcts were observed in patients with SVBA than in those with stenotic NVBA. Conclusions FPC does not protect against infratentorial PCS. Regardless of extensive arterial lesions, relatively small infarcts may be due to previously established collaterals from the LCA, which could compensate for the defects in the infratentorial area.

Rotational vertebrobasilar ischemia due to vertebral artery dynamic stenoses complicated by an ostial atherosclerotic stenosis

We describe a patient with rotational vertebrobasilar ischemia (RVBI) due to vertebral artery (VA) compressive stenoses during neck rotation, complicated by an ostial atherosclerotic stenosis (OAS). Referred for 'near-syncopal spells', inquiry revealed a symptom-complex consistent with vertebrobasilar transient ischemic attacks (TIAs) provoked by head rotation. VA dynamic angiography with imaging via prevertebral subclavian injections in neck-rotated positions while reproducing symptoms, demonstrated two compressive stenoses not present in the neck-neutral position, establishing the diagnosis of RVBI due to CT-demonstrated cervical spondylosis. There was an occluded contralateral VA, isolated posterior circulation, and absent vertebral collateral flow. Disabling symptoms persisted despite using a cervical collar. Surgical decompression of the dynamic stenoses would not address the OAS, was considered high risk, and absence of a suitable donor artery precluded distal VA reconstruction. RVBI resolved with ostial stent placement by improving perfusion pressure across the compressive stenoses. To our knowledge, this is the first report of RVBI in which the affected VA had an obstructive atherosclerotic stenosis in addition to the characteristic rotation-induced dynamic stenoses, and the first report of stent placement in the culprit artery to treat this disorder. Diagnosis depends on recognizing the association of symptoms with positional neck changes and VA dynamic angiography demonstrating the compressive stenosis while reproducing symptoms. This case illustrates the management complexities when there are coexisting abnormalities, emphasizing the need to individualize treatment. RVBI is a potentially correctable cause of TIAs and particularly relevant due to the aging population which has a significant incidence of both degenerative cervical and atherosclerotic cerebrovascular disease.

Experimental Model of Brainstem Stroke in Rabbits via Endovascular Occlusion of the Basilar Artery

Basilar artery thrombosis remains a significant clinical problem, and no reproducible animal model has been established to study the stroke within the vertebrobasilar distribution. We report a study designed to pilot test a novel model of brainstem stroke in rabbits, created by selective endovascular occlusion of the basilar artery. Basilar artery occlusion was induced in 8 New Zealand white rabbits by injection of the autologous clot through the microcatheter positioned within the distal vertebral artery. Animals were divided into subgroups (I and II) based on the length of produced ischemia (3 and 6 hours, respectively). Magnetic resonance (MR) imaging of the brain and MR angiography of the intracranial vessels were performed before the procedure, and at 3 hours after induced ischemia for groups I and II, with continued imaging up to 6 hours for group II, with diffusion-weighted images acquired approximately every 30 minutes. Animals were killed at the end of the 3-hour (group I) or 6-hour (group II) ischemia time. Brainstem stroke was successfully induced in all animals, with pathological changes documented in all cases. The earliest changes of ischemia on MR diffusion-weighted images were identified at only 4.5 hours of basilar artery occlusion. These results suggest that a reproducible model of brainstem stroke can be induced in rabbits using selective endovascular occlusion of the basilar artery. The availability of such a model, integrated with state-of-the-art imaging techniques, holds promise for preclinical investigations of emergent therapeutic approaches in stroke.

Incidence of unilateral distal vertebral artery aplasia: evaluation by combining basiparallel anatomic scanning-magnetic resonance imaging (BPAS-MRI) and magnetic resonance angiography

The incidence of a unilateral aplastic distal vertebral artery (VA) has been reported as 0.2% of cases on cerebral angiography. During our daily magnetic resonance (MR) examinations, however, we frequently encounter MR angiograms (MRAs) that do not demonstrate unilateral VA. The purpose of this study was to calculate the frequency of aplastic unilateral distal VA by MR images performed for asymptomatic people. Over a time span of 1 year, 237 asymptomatic people (140 men, 97 women; ages 28-67 years, mean 54.4 years) underwent brain MRI during a "brain check-up examination" in our hospital. To identify an aplastic unilateral distal VA, we retrospectively compared three-dimensional time-of-flight MRA with basiparallel anatomic scanning (BPAS)-MRI which was designed for recognition of the arterial outer contour. Aplasia of the unilateral distal VA was confirmed in 11 persons (4.6%). According to our classification, hypoplastic distal VA in 12 (5.1%) and asymptomatic acquired unilateral distal VA occlusion was also proved in 2 (0.8%). We found that the frequency of aplastic unilateral VA was 4.6% in asymptomatic people using a combination of MRA and BPAS-MRI for assessment of an intracranial VA.

Anterior Spinal Artery as a Collateral Channel in Patients With Acute Bilateral Vertebral Artery Occlusions -Two Case Reports-

Retrograde flow through the anterior spinal artery (ASA) from the cervical vertebral artery (VA) to the intracranial distal VA due to disrupted perfusion caused by bilateral VA occlusion is rare. We report two cases of hemodynamic vertebrobasilar circulatory insufficiency caused by bilateral VA occlusion. In these patients, the ASA filled in the retrograde direction, and provided collateral support to the ipsilateral posterior inferior cerebellar artery. The patients were treated with drip intravenous infusion of edaravone and/or argatroban. One patient had a good collateral supply from the posterior communicating artery and recovered almost completely within one month, but the other did not and lapsed into a coma, with generalized hyperreflexia, pin-point pupils, and ataxic respiration. Severe calcified lesions on three-dimensional computed tomography angiography at the occlusion site in the second patient indicated direct surgery including right superficial temporal artery to superior cerebellar artery anastomosis, rather than the endovascular approach. Retrograde flow through the ASA may be observed in this type of critical situation, and may be an important source of collateral supply to the posterior fossa territory.

Traumatic rupture of the intracranial vertebral artery due to rotational acceleration

The reason for blunt forces against the head to rupture the basal brain arteries has been discussed in forensic and trauma research. However, well-documented case reports demonstrating the mechanism of injury, the clinical course and the forensic work up are rare. We present the case of a 40-year-old man, who was assaulted with blunt force to the head resulting in death 34 h later from a longitudinal rupture of the distal left vertebral artery. Computer tomography of the brain and the face demonstrated a basal subarachnoidal haemorrhage, signs of increased intracranial pressure and a fracture of the right orbital bone. Angiography showed a long fusiform dilatation of both intracranial vertebral arteries with an active pseudoaneurysm on the left side. At autopsy signs of a blunt trauma to the head, extensive basal subarachnoidal haemorrhage and a minor subdural haemorrhage were found. Histological examination revealed a transmural longitudinal rupture of the left vertebral artery with vital reaction and no signs of preexisting vascular disease. We discuss the current literature regarding traumatic basal brain artery rupture, important clinical decision making processes as well as pitfalls in the forensic work up. In addition, this singular well-documented case gives new insights in the underlying pathophysiological mechanisms of traumatic basal artery rupture.

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.

Ultrasonic diagnosis of the vertebrobasilar system. II. Transnuchal diagnosis of intracranial vertebrobasilar stenoses using a novel pulsed Doppler system

This report deals with the non-invasive detection of haemodynamically non-significant stenoses of the intracranial part of the vertebrobasilar system. A new Doppler device transmitting pulsed 2 MHz ultrasound was used. Among 67 patients with transient or stable neurological deficits of the posterior circulation area, five were found to have stenoses of the distal vertebral artery or basilar artery, respectively. Transnuchal approach via the foramen magnum was used. The findings were confirmed by angiography. Twelve subjects with normal Doppler findings also underwent angiography. Three of them presented irregularities and plaquing of the vertebrobasilar trunk without circumscribed stenosing lesions. Transcranial pulsed Doppler sonography permits non-invasive detection of intracranially located stenoses of the vertebrobasilar system which, up to now, could not be diagnosed with the help of extracranial conventional continuous-wave Doppler alone. This new method allows early detection of basilar artery occlusive disease. The effectiveness of anticoagulation and fibrinolysis can be assessed non-invasively.

Treatment of a complex posterior fossa aneurysm in a child using side-to-side posterior inferior cerebellar artery–posterior inferior cerebellar artery bypass

Endovascular and cerebral bypass therapies are rarely used in children. The authors describe the treatment of a partially coiled giant distal vertebral artery (VA)-posterior inferior cerebellar artery (PICA) aneurysm in a child. They performed a side-to-side PICA-PICA anastomosis followed by endovascular VA aneurysm deconstruction with PICA preservation. A healthy 11-year-old boy developed progressive holocephalic headaches over the course of 2 months. Magnetic resonance imaging and magnetic resonance angiography revealed a large right PICA aneurysm causing brainstem compression. In November 2005, 2 Neuroform stents and Guglielmi detachable coils and Matrix were placed in the aneurysm at an outside institution. In 2006, angiography demonstrated aneurysm enlargement from which the PICA originated, coil compaction, and increased mass effect. The patient underwent a PICA-PICA bypass with intraoperative flow measurements followed by endovascular embolization of the aneurysm and parent VA. An angiogram obtained after the procedure demonstrated filling of the right PICA medullary branch through the bypass and obliteration of the aneurysm. The patient remained neurologically intact. Giant aneurysms of the posterior circulation are rare but do occur in children. With the aid of combined surgical and endovascular strategies the authors were able to safely eliminate the aneurysm from circulation with good outcome. Cerebral bypass and endovascular deconstructive therapies can be used safely in children but should be reserved for cases in which direct treatment carries significant risk. Careful surgical and endovascular planning with intraoperative flow assessment is essential for good outcome.