Clinical evaluation of mechanical thrombectomy for patients with posterior circulation occlusion: A retrospective study.

OBJECTIVE: Although consensus has been reached regarding the use of mechanical thrombectomy for acute large anterior circulation occlusion, its effectiveness in patients with posterior circulation occlusion remains unclear. This study aimed to establish the determining factors for good clinical outcomes of mechanical thrombectomy for posterior circulation occlusion. METHODS: We extracted cases of acute large vessel occlusion (LVO) in the posterior circulation from a database comprising 536 patients who underwent mechanical thrombectomy at our hospital between April 2015 and March 2021. RESULTS: Fifty-two patients who underwent mechanical thrombectomy for LVO in the posterior circulation were identified. Five patients with simultaneous occlusion of the anterior and posterior circulation were excluded; finally, 47 patients were included in this study. The median patient age was 78 years, and 36% of the patients were women. The median National Institutes of Health Stroke Scale (NIHSS) score on admission was 31, the median posterior circulation-Alberta Stroke Program Early Computed Tomography Score (pc-ASPECTS) was 8, and the median Basilar Artery on Computed Tomography Angiography (BATMAN) score was 6. The rate of good recanalization (Thrombolysis in Cerebral Infarction scale grades 2b and 3) was 96%, and a good prognosis (modified Rankin Scale score of 0-2 at 90 days) was achieved in 19 patients (40%). The median pc-ASPECTS was significantly higher in the good prognosis group than in the poor prognosis group (10 vs. 7; p = 0.007). The median NIHSS score at presentation was significantly lower in the good prognosis group than in the poor prognosis group (17 vs. 34; p = 0.02). The median BATMAN score was significantly higher in the good prognosis group than in the poor prognosis group (8 vs. 3.5; p = 0.0002). Multivariate analysis showed that an NIHSS score ≦ 20 at presentation was the only independent factor for good prognoses. CONCLUSION: The prognosis of mechanical thrombectomy for posterior circulation LVO was better in patients with lower NIHSS scores at presentation.

Transcervical Vertebral Artery Origin Endarterectomy for Vertebrobasilar Insufficiency.

Vertebral artery (VA) stenosis is a cause of vertebrobasilar insufficiency (VBI) and disabling posterior circulation stroke,1 accounting for up to 30% of all strokes.2 Although the natural history of VBI is not as well delineated as that of carotid stenosis, strokes in the basilar circulation can be more disabling than their anterior circulation counterparts. Stenosis exceeding 30% at the origin of the vertebral artery is associated with increased risk of stroke.3 The authors present a case of a female patient with significant peripheral vascular disease who presented with concerns for VBI. The patient was on antiplatelet and anticoagulative medications and a statin at the time of her presentation. Angiography demonstrated bilateral vertebral artery origin stenosis. The left VA was diminutive and arose directly from the arch (Video 1). The right VA demonstrated critical stenosis at its origin. Attempts at endovascular access of the right VA for placement of a balloon-mounted stent were unsuccessful. The patient underwent a transcervical approach for endarterectomy of the VA origin. The VA can be readily accessed using a small supraclavicular incision to isolate the V1 segment of the vessel. The procedure was performed with the patient heparinized and on antiplatelet medications. Alternatives to this strategy include patch grafting in addition to the endarterectomy or use of a short vein graft to bypass the stenosis of the VA beyond the stenotic segment.

Safety and Efficacy of Low-Profile Braided Stents versus Flow Diverters in the Reconstructive Technique in the Treatment of Patients with Vertebrobasilar Dolichoectasia Aneurysms: A Cohort of 47 Patients with Long-Term Follow-Up.

BACKGROUND AND PURPOSE: Vertebrobasilar dolichoectasia aneurysm is a rare type of cerebrovascular disorder with a poor natural history, and endovascular treatment is widely accepted. Whether a high-profile braided stent (flow diverter) could promote occlusion of vertebrobasilar dolichoectasia aneurysm without increasing the complications rather than a low-profile braided stent remains uncertain. The aim of the study was to present a single-center experience of the safety and efficacy of a low-profile braided stent versus a flow diverter in treating patients with vertebrobasilar dolichoectasia aneurysms. MATERIALS AND METHODS: The retrospective review was conducted on a total of 432 consecutive patients diagnosed with posterior circulation aneurysms who underwent endovascular treatment in our center from August 2013 to December 2021. Among these patients, 47 individuals with vertebrobasilar dolichoectasia aneurysms who were treated with low-profile braided stents or flow diverters were included. Vertebrobasilar dolichoectasia aneurysms involving only the vertebral artery were excluded. Patients were divided into 2 groups: the low-profile braided stent group and the flow diverter group based on the device used. Safety and efficacy outcomes were subsequently analyzed. RESULTS: There were 25 total patients enrolled in low-profile braided stent group and 22 patients in flow diverter group. The safety of low-profile braided stents and flow diverters in the treatment of vertebrobasilar dolichoectasia aneurysms was evaluated by clinical outcome, a new neurologic deficit due to procedural complications, and neurologic death. The rates of good clinical outcome were similar between the 2 groups (low-profile braided stent, 56%, versus flow diverter, 59.1%; P = .831), and the rates of neurologic death were also similar (low-profile braided stent, 12%, versus flow diverter, 9.1%; P = .747). Higher rates of new neurologic deficits due to procedural complications were observed in the flow diverter group, but the difference was not significant (low-profile braided stent, 24%, versus flow diverter, 40.9%; P = .215). The efficacy was evaluated by angiographic occlusion of vertebrobasilar dolichoectasia aneurysms and progression of mass effect resulting from these aneurysms. Significantly higher rates of complete occlusion of vertebrobasilar dolichoectasia aneurysms were shown in the flow diverter group (41.2%; P = .028) than in the low-profile braided stent group (10%). CONCLUSIONS: Both low-profile braided stents and flow diverters have similar high risks in reconstructive techniques in the treatment of vertebrobasilar dolichoectasia aneurysms, while a flow diverter is more effective in promoting complete occlusion of vertebrobasilar dolichoectasia aneurysm than a low-profile braided stent. A flow diverter may be a better alternative for carefully selected patients with vertebrobasilar dolichoectasia aneurysms.

Hidden Bow Hunter's Syndrome Diagnosed Using Dynamic Cerebral Angiography and Successfully Treated with Spinal Surgery: A Case Report and Review of the Literature.

Hidden bow hunter's syndrome (HBHS) is a rare disease in which the vertebral artery (VA) occludes in a neutral position but recanalizes in a particular neck position. We herein report an HBHS case and assess its characteristics through a literature review. A 69-year-old man had repeated posterior-circulation infarcts with right VA occlusion. Cerebral angiography showed that the right VA was recanalized only with neck tilt. Decompression of the VA successfully prevented stroke recurrence. HBHS should be considered in patients with posterior circulation infarction with an occluded VA at its lower vertebral level. Diagnosing this syndrome correctly is important for preventing stroke recurrence.

Bilateral Hunter's bow syndrome: a rare case diagnosed by dynamic digital subtraction angiography.

A 27-year-old female patient suffered from recurrent episodes of dizziness, visual rotation, and intermittent right-hand numbness over one month. Symptoms persisted and were triggered by rotating the head to the right or left for more than 10 seconds. Neurological examination showed that the symptoms were most pronounced when the head was rotated over 45 degrees to the right. Dynamic digital subtraction angiography (dDSA) was performed to confirm the diagnosis. Leftward head rotation caused occlusion of the right vertebral artery(VA) . However, the symptoms were mild, owing to sufficient compensation by the right posterior communicating artery (PCA) . Rightward head rotation exceeding 45 degrees resulted in occlusion of the left VA. The resultant symptoms were pronounced due to inadequate compensation of the left PCA. CT angiographic reconstruction showed bilateral vertebral arteries with tortuous loops of vessels at the level of the C2 vertebrae . CT images showed no cleavage between the left VA and the anterior surface of the left C2 transverse foramen. Conservative treatment was recommended considering the patient's young age and limited severity of her symptoms. Bow Hunter's syndrome is a rare neurovascular disorder characterized by dynamic occlusion of the VAs during head rotation, leading to inadequate blood flow to the posterior cerebral circulation. Bow hunter syndrome, where bilateral dynamic occlusion occurs without a discernible dominant side of the VA, is uncommon. The medical community must acknowledge cervical vertigo as a distinct disorder. dDSA remains the gold standard for its diagnosis.

Bow Hunter Syndrome: An Illustrative Case and Operative Management.

The differential for vertebrobasilar insufficiency is wide and can be caused by posterior circulation infarcts, steal-type phenomena, or other systemic causes. In the absence of imaging findings explaining symptomology, the utility of appropriate history gathering and dynamic angiography cannot be understated in identifying Bow Hunter's syndrome, a rare cause of dynamic vertebrobasilar insufficiency. We present a case of a 69-year-old man who complained of presyncope and severe dizziness when turning his head towards the right. On examination he had no radiculopathy but did have objective evidence of myelopathy. Computed tomography imaging and dynamic angiography demonstrated C3-C4 right uncovertebral joint hypertrophy and near complete stenosis of the right vertebral artery with dynamic head position towards the right. Given vertebrobasilar insufficiency and myelopathy, he was taken to the operating room for C3-C4 anterior cervical discectomy and fusion with vertebral artery decompression (Video 1). The patient provided consent for the procedure. Standard anterior cervical neck dissection was undertaken with additional platysmal undermining to facilitate exposure of the right uncovertebral joint and transverse processes. The vertebral artery was first decompressed above and below the area of most significant stenosis at the respective transverse foramina before the hypertrophied uncovertebral joint was removed. Next, discectomy and posterior osteophyte removal were completed in typical fashion followed by graft, plate, and screw placement. Postoperatively the patient had immediate resolution of symptoms and continued so at eight month follow-up. Imaging demonstrated return to normal caliber of the right vertebral artery and successful decompression.

Superior cerebellar artery occlusion remaining after thrombectomy for acute basilar artery occlusion.

To investigate the incidence and impact of superior cerebellar artery (SCA) occlusion remaining after thrombectomy for acute basilar artery occlusion (BAO). We retrospectively analyzed data from 116 patients who underwent thrombectomy for BAO. The patency of SCA was assessed on final angiograms. Clinical and radiologic data of the patients were retrieved from a prospectively collected database and analyzed. All patients underwent pretreatment and follow-up DWI to detect new infarctions in SCA territory. Ten patients (8.6%) had SCA occlusions on final angiograms. Of these, two patients had bilateral occlusions. A new infarction with a diameter ranged from 4 to 11 mm in corresponding SCA territory occurred in 5 of 10 patients. No patients with SCA occlusions experienced symptomatic cerebellar hemorrhage or malignant cerebellar infarction. Nine of 12 SCA occlusions showed spontaneous recanalization on follow-up CT angiography. Four of 10 patients showed 90-day favorable outcome (mRS 0-3) and 90-day mortality occurred in one patient. SCA occlusions remaining after thrombectomy for acute BAO had a benign clinical course. Most of these lesions recanalized spontaneously. Our study suggests that attempts to recanalize remnant SCA occlusion may be unnecessary after basilar artery thrombectomy.

[Vertebrobasilar insufficiency caused by extravasal compression of the vertebral artery in the second segment]. / Vertebral'no-bazilyarnaya nedostatochnost', vyzvannaya ekstravazal'noi kompressiei pozvonochnoi arterii vo vtorom segmente.

OBJECTIVE: To develop indications for surgical treatment for positional disorders of blood flow in the vertebral-basilar territory caused by the damage to the V2-V3 segment of the vertebral artery (VA). MATERIAL AND METHODS: One hundred and fourteen patients with systemic and non-systemic dizziness were studied. To assess the state of the VA, blood circulation of the posterior cranial fossa and the base of the brain, ultrasound duplex scanning of blood vessels, selective angiography, MRI, single photon emission computed tomography (SPECT) of the brain and neuropsychological testing were performed. Patients were divided into three groups according to the severity of clinical manifestations of vertebrobasilar insufficiency (VBI). RESULTS: According to ultrasound data, patients of the third group with severe VBI had signs of extravasal compression in 94.3% of cases. In the same group, there was an increase in the systolic-diastolic (S/D) ratio by more than 2.5-3 times, as well as an increase in the resistive index (RI) by more than 1.75 units and pulsation index (PI) more than 2.2 units in V2-V3 segments of VA. In 42.9% of patients of the third group, zones of a decrease in the accumulation of 99mTc-ECD by more than 20% were found in the occipital region during the De Klein test. A direct correlation was established between the clinical manifestations of VBI and a decrease in perfusion during SPECT by 20% or more with the De Klein test (r=0.7). We developed an algorithm for diagnosing high-grade VBI with subsequent identification of a causal relationship with extravasal component effects on VA in the second segment. Indications for surgical intervention were determined in 33 patients with clinical manifestations of blood flow decompensation in the posterior cranial fossa. CONCLUSION: Decreased blood flow velocity in the vertebral or basilar artery by more than 50% with a decrease in PI, breath holding index <0.7 in the hypercapnic test, and no increase in blood flow velocity in a phototest and, in addition, the >20% defect of 99mTc-ECD accumulation in the posterior parts of the brain during SPECT with a De Klein test are the criteria for decompensation of blood flow in the vertebral-basilar territory, requiring surgical correction.

Dynamic and visual nomograms to online predict unfavorable outcome of mechanical thrombectomy for acute basilar artery occlusion.

BACKGROUND: The evidence of mechanical thrombectomy (MT) in basilar artery occlusion (BAO) was limited. This study aimed to develop dynamic and visual nomogram models to predict the unfavorable outcome of MT in BAO online. METHODS: BAO patients treated with MT were screened. Preoperative and postoperative nomogram models were developed based on clinical parameters and imaging features. An independent dataset was collected to perform external validation. Web-based calculators were constructed to provide convenient access. RESULTS: A total of 127 patients were included in the study, and 117 of them were eventually included in the analysis. The nomogram models showed robust discrimination, with an area under the receiver operating characteristic (ROC) of 0.841 (preoperative) and 0.916 (postoperative). The calibration curves showed good agreement. The preoperative predictors of an unfavorable outcome were previous stroke, the National Institutes of Health Stroke Scale (NIHSS) at admission, and the posterior circulation Alberta Stroke Program Early Computed Tomography Score (pc-ASPECTS). The postoperative predictors were previous stroke, NIHSS at 24 h, and pc-ASPECTS. CONCLUSION: Dynamic and visual nomograms were constructed and validated for the first time for BAO patients treated with MT, which provided precise predictions for the risk of an unfavorable outcome. The preoperative model may assist clinicians in selecting eligible patients, and the postoperative model may facilitate individualized poststroke management.

Association between vertebrobasilar artery geometry and vertebrobasilar stenosis, recurrence, and death in posterior circulation stroke and transient ischemic attack.

BACKGROUND: Intracranial atherosclerosis is one of the primary causes of posterior circulation stroke and transient ischemic attack (TIA), particularly in people of South and East Asian heritage. Focal vessel geometry may play a role in atherosclerosis progression. Thus, we investigated the relevance of vertebrobasilar artery (VBA) geometry and vertebrobasilar atherosclerotic stenosis, recurrence, and death in posterior circulation stroke and TIA. METHODS: Four hundred and twenty patients with posterior circulation ischemic stroke or TIA were included. The VBA geometric features, comprising the geometric configurations (Tuning fork, Walking, Lambda, and No confluence), vascular bends (multi-bending and oligo-bending), and VBA stenosis degrees, were defined based on computed tomography angiography (CTA) images. Recurrence of stroke or TIA and death were assessed through a 1-year follow-up. Additionally, the relationship between VBA geometric features, VBA stenosis, and prognosis were analyzed. RESULTS: Walking type and vascular multi-bending showed significant associations with more severe VBA stenosis and distribution, and these were also more frequently observed in patients with large-artery atherosclerosis (LAA) stroke (all P < 0.05). Sixty-four patients exhibited recurrent stroke or TIA, and 31 died during the 1-year follow-up. In the binary logistic regression analysis, Walking type (P = 0.018), Lambda type (P = 0.021), and multi-bending type (P = 0.004) were found to be independently associated with stroke recurrence, while No confluence type was independently associated with death (P = 0.010). CONCLUSIONS: The geometric characteristics of the VBA are associated with vertebrobasilar stenosis, LAA stroke, 1-year recurrence, and death in posterior circulation stroke and TIA. VBA geometry may be used to stratify the risk of stroke and TIA in the posterior circulation.

Acute Vertebrobasilar Artery Occlusion with Underlying Atherosclerosis: Balloon Angioplasty Combined with Tirofiban as Initial Salvage Therapy.

OBJECTIVE: The optimal rescue endovascular treatment for patients with intracranial atherosclerotic stenosis in acute vertebrobasilar artery occlusion is not well established. We investigated the safety and efficacy of balloon angioplasty combined with tirofiban as the initial rescue strategy in these patients. METHODS: We retrospectively analyzed the records of 41 patients admitted between January 2014 and September 2022, with vertebrobasilar artery atherosclerotic occlusion. Balloon angioplasty in combination with tirofiban was used as the first-line salvage therapy after the failure of mechanical thrombectomy. The technical success rate, recanalization outcome, procedure-related complications, symptomatic intracranial hemorrhage, and functional outcome at 90 days were reviewed. RESULTS: Recanalization with a modified Thrombolysis in Cerebral Infarction grade of 2b-3 was achieved in 38 of the 41 patients (92.7%). Acute stents were deployed in 5 patients who did not achieve successful reperfusion after balloon angioplasty. Six patients (14.6%, 6/41) underwent stent angioplasty in the stable stage for severe residual stenosis detected on follow-up imaging. There was no procedure-related complication. Hemorrhagic transformation was detected on follow-up imaging in 11 patients (26.8%), while no symptomatic intracranial hemorrhage was recorded. Good functional outcome rate was 31.7% (13/41). CONCLUSIONS: Balloon angioplasty combined with intravenous tirofiban administration is a safe and effective salvage therapy in patients with acute atherosclerotic occlusion of the vertebrobasilar artery.

Imaging features of vertebrobasilar dolichoectasia combined with posterior circulation ischemic stroke: A vessel wall magnetic resonance imaging study.

PURPOSE: To elucidate the vessel wall changes of vertebrobasilar dolichoectasia (VBD) with ischemic stroke, using vessel wall magnetic resonance imaging (VW-MRI). METHOD: Thirty-four patients with VBD (22 with stroke and 12 without stroke) who underwent VW-MRI were recruited. Forty-one patients without VBD who underwent VW-MRI were also recruited if they had a recent stroke due to atherosclerosis in the basilar artery or the intracranial vertebral artery. The vessel wall features of VBD were compared between stroke and non-stroke groups. The plaque characteristics were compared between VBD and non-VBD stroke patients. RESULTS: The frequency of plaques was higher (54.5% vs. 8.3%, P = 0.011) in VBD patients with stroke than that in non-stroke patients, while the frequencies of aneurysm, dissection, intraluminal thrombus, and diffuse/concentric wall enhancement did not differ. When the plaque features were compared between plaque-positive stroke patients with and without VBD, the degree of stenosis (31.0% ± 26.8% vs. 71.5% ± 19.0%, P < 0.001), normalized wall index (NWI) (0.7 ± 0.1 vs. 0.9 ± 0.1, P < 0.001), and remodeling index (RI) (1.0 ± 0.4 vs. 1.3 ± 0.4, P = 0.023) were lower in the VBD group, while intraplaque hemorrhage, and enhancement ratio showed no difference. CONCLUSIONS: This preliminary study suggests that atherosclerosis may be an important cause of stroke in VBD patients. Symptomatic plaques in VBD patients have a lower degree of stenosis, NWI, and RI than that in non-VBD patients. VW-MRI may help to assess stroke mechanisms and identify VBD patients at high risk.

Basilar artery diameter as neuroimaging biomarker in Chinese Fabry disease patients.

BACKGROUND: Fabry disease (FD) is an X-linked lysosomal storage disease resulting from mutations of α-galactosidase A gene, and has been emphasized as one of the etiologies of young stroke and leukoencephalopathy. Vertebrobasilar dolichoectasia (VBD) is a highlighted finding in FD. We aim to examine the utility of VBD in Chinese FD by comparing the differences in basilar artery (BA) diameter of Chinese FD patients against age-matched controls with and without stroke. METHODS: This was a matched case-control study involving 37 Chinese FD patients. The BA diameters were evaluated on axial T2-weighted magnetic resonance imaging and compared to two age-and-gender matched control groups, one with stroke and one without. The association between BA diameter and stroke occurrences and white matter hyperintensities (WMH) were analyzed among all FD patients. RESULTS: Patients with FD had significantly increased BA diameter compared to controls with and without stroke (p < 0.001). A BA diameter of 4.16 mm could distinguish FD from controls in the stroke subgroup (ROC AUC 0.870, p = 0.001, sensitivity 80% specificity 100%), and with a cut-off of 3.21 mm in the non-stroke subgroup (ROC AUC 0.846, p < 0.001, sensitivity 77.8% specificity 88.9%). Larger BA diameter had more stroke occurrences and was moderately associated with heavier WMH load in terms of higher total FAZEKAS scores. (Spearman's rho = 0.423, p = 0.011). CONCLUSION: VBD was also present in Chinese FD patients. BA diameter has high diagnostic utility in identifying FD from a mixed cohort of stroke and normal controls, and carried predictive value in evaluating neurological complications of FD.

Predictive Value of a Novel Baseline Diffusion-Weighted Imaging Posterior Circulation Score in Endovascular Treatment of Patients with Acute Vertebrobasilar Occlusion.

RATIONALE AND OBJECTIVES: To investigate the predictive value of a novel posterior circulation score (novel-PC score) based on baseline posterior circulation diffusion-weighted imaging (DWI) for functional independence after endovascular treatment (EVT) in patients with acute vertebral-basilar artery occlusion (VBAO). MATERIALS AND METHODS: The baseline DWI brain stem score (BSS), posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS), and the novel-PC score were evaluated separately. A modified Rankin scale (mRS) ≤2 at 90 days was defined as a prognostic indicator of functional independence. Modified Thrombolysis in Cerebral Infarction grade 2b or 3 was defined as surgical success. RESULTS: A total of 64 eligible patients were enrolled and divided into good and poor functional prognosis groups based on the mRS. The novel-PC score, BSS, and pc-ASPECTS (all P ≤ .001) were significantly better in the good functional prognosis group. The novel-PC score had a higher predictive value than BSS and pc-ASPECTS for 90-day functional independence (area under the receiver operating characteristic curve, 0.87 vs. 0.73 vs. 0.71; P < .05). Univariate binary logistic regression analysis showed that age (P = .006), Posterior National Institutes of Health Stroke Scale ≤18 (P < .001), BSS ≤2 (P = .008), pc-ASPECTS >7 (P = .002), and novel-PC score ≤5 (P = .001) were independently associated with function. CONCLUSION: Our novel-PC score, based on DWI, can independently predict functional prognosis in patients with acute VBAO after EVT. CLINICAL RELEVANCE: The novel-PC score based on baseline DWI was shown to be an independent predictor of function in patients with acute BVAO who are treated with EVT.

Intravascular ultrasound guided vertebral artery stenting after basilar artery thrombectomy for acute brain stem stroke.

A 64-year-old lady presented as right vertebral artery occlusion and brain stem stroke (Figure 1A). Emergent thrombectomy opened the artery, but it re-occluded 10 minutes later (Figure 1B,C). Intravascular ultrasound showed heavy plaque burden and guided a balloon-expandable stenting successfully (Figure 1D-F).