Differences and Advantages of Particles versus Liquid Material for Preoperative Intracranial Tumor Embolization: A Retrospective Multicenter Study.

Objectives: The superiority and usefulness of liquid material over particles for embolization have been a topic of debate due to differences in materials and techniques. This study aimed to identify the complications and outcomes associated with both embolization materials. Methods: This retrospective multicenter cohort study included 93 patients from an endovascular treatment registry, treated from January 1, 2018 to May 31, 2022. It included patients who underwent preoperative embolization for meningioma, solitary fibrous tumor/hemangiopericytoma, and hemangioblastoma. Data for patient characteristics, procedural factors, complications, and outcomes were collected from medical records. Results: A tortuous access route was the only factor independently associated with complications (p = 0.020). Although liquid material was more frequently used for embolization in relatively high-risk conditions, complication rates did not differ significantly between the groups (p = 0.999). In the liquid material group, the tip of the microcatheter could be guided closer to the tumor (p <0.001) using a distal access catheter and flow-guide microcatheters. The subgroup middle meningeal artery embolization had less operative bleeding in the liquid material group (p <0.001), whereas the particles group exhibited less intraoperative blood loss than the liquid material group (p = 0.006). Conclusion: The vascular tortuosity of the access route was only associated with complications in preoperative tumor embolization. Liquid material and particles showed no difference in complication rates. The use of particles in embolization may reduce intraoperative bleeding, but not in all cases can it be used safely. Therefore, a thorough understanding of the characteristics of both approaches and their relative advantages in clinical practice is essential to opt for the appropriate material according to the case.

Embolic Material Migration as the Predominant Contributing Factor to Prognostic Deterioration Following Combined Tumor Resection and Preoperative Embolization.

Introduction Preoperative embolization can potentially facilitate surgical resection of challenging tumors in the intracranial and facial regions; however, its clinical efficacy remains controversial, mainly due to potential morbidity risks. We explored negative factors of the combined treatment of preoperative embolization and tumor resection that affect neurological prognosis. Method This retrospective study used clinical data from 132 consecutive tumors that underwent combined treatment at multiple facilities between January 2016 and May 2021. Basic patient information, tumor characteristics, and treatment details were assessed to identify predictors of deterioration as measured using the modified Rankin scale (mRS) score at three months post-treatment. Results Among the 126 eligible combined treatments, a deterioration in the postoperative mRS score was observed in 19/126 (15.1%). Complications related to embolization and tumor resection occurred in 8/126 (6.3%) and 19/125 (15.2%) of procedures, respectively. Multivariate analyses indicated significant associations between migration of embolic material (adjusted odds ratio 13.80; 95% confidence interval 1.25-152.52; p=0.03), elevated intraoperative blood loss (p=0.04), and deterioration of postoperative mRS score. Embolic material migration was identified as the primary prognostic factor for the deterioration of score. An analysis of 192 procedures, excluding those that exclusively used coils, identified embolization targeting the accessory meningeal artery (p=0.046) and the third segment of the internal maxillary artery (p=0.03) as a risk factor for embolic material migration. Conclusions Embolic material migration is the predominant factor associated with declining neurological outcome that persists into the chronic phase after combined treatment. Given that preoperative embolization is a supplementary treatment option, a thorough understanding of vascular anatomy and striving safe procedure are critical.

Coaxial Method of PTA Balloon and Aspiration catheter using the delivery wire of a stent retriever for tandem occlusion: CoMBAt tandem occlusion.

PURPOSE: Tandem occlusion, in which the intracranial artery is obstructed along with proximal carotid occlusive or stenotic lesions, occurs in 10-15% of patients with large vessel occlusion. Our study introduces a novel technique for tandem occlusion treatment that involves the simultaneous coaxial deployment of a percutaneous transluminal angioplasty balloon and aspiration catheters with the delivery wire of a stent retriever. After percutaneous transluminal angioplasty of the carotid lesion with a thin balloon catheter, the aspiration catheter was advanced over the balloon to eliminate the ledge between the catheter tip and delivery wire. After balloon removal, intracranial thrombectomy was performed using an aspiration catheter and stent retriever. This study aimed to evaluate the safety and efficacy of this approach. MATERIALS AND METHODS: Medical records of patients with acute stroke due to tandem occlusion treated using our technique were analyzed for its effectiveness and safety. The puncture-to-recanalization time, modified thrombolysis in cerebral infarction (mTICI) grade, functional prognosis and incidence of hyperperfusion were assessed. RESULTS: Seven patients were included in this study. In all patients, mTICI 2b-3 recanalization was achieved after smooth delivery of the aspiration catheter from the carotid lesion to the intracranial thrombus. The median puncture-to-recanalization time was 52 min. Ninety days post-stroke onset, six of seven patients had a modified Rankin Scale score of 0-2, and none of the patients had perioperative hyperperfusion syndrome. CONCLUSION: Our technique allows simultaneous treatment of carotid and intracranial lesions, leading to faster recanalization. Furthermore, percutaneous transluminal angioplasty with a thin balloon may reduce the risk of hyperperfusion.

Efficacy and Safety of Lumbar Drainage before Endovascular Treatment for Ruptured Intracranial Aneurysms.

Objective: Intraoperative rebleeding during endovascular treatment for ruptured intracranial aneurysms is associated with poor prognosis. Lumbar drainage is performed preoperatively to control intracranial pressure; however, it is associated with a risk of brain herniation or rebleeding because intracranial pressure may change rapidly. Therefore, this study aimed to examine the efficacy and safety of preoperative lumbar drainage. Methods: This retrospective study enrolled 375 patients who underwent endovascular treatment of ruptured intracranial aneurysms at our institution between April 2013 and March 2018. The incidence of rebleeding and clinical outcomes were compared between patients who did and did not undergo preoperative lumbar drainage. Results: Among the 375 patients with ruptured intracranial aneurysms, 324 (86.0%) and 51 (14.0%) patients did and did not undergo lumbar drainage, respectively. The incidence of rebleeding was 11/324 (3.4%) and 2/51 (3.9%) in lumbar drainage and nonlumbar drainage groups, respectively, with no statistical differences (p = 0.98). Of the rebleeding cases, 9/11 (81%) and 2/2 (100%) in lumbar drainage and nonlumbar drainage groups, respectively, were due to intraoperative bleeding, and 2/11 (19%) in the lumbar drainage group, the causes of the rebleeding were undetermined. The incidence of symptomatic vasospasm did not differ significantly between the groups (13.2% vs. 11.8%, P = 0.776), while the incidence of hydrocephalus (24.6% vs. 11.8%, P = 0.043) and meningitis (15.2% vs. 5.9%, P = 0.075) were slightly higher in the lumbar drainage group. Favorable clinical outcomes (modified Rankin Scale score <2) at discharge were less frequent in the lumbar drainage group (55.3% vs. 70.0%, P = 0.051). No significant differences were observed in the propensity score-matched analysis. Conclusion: Lumbar drainage before endovascular treatment for ruptured intracranial aneurysms is a safe procedure that does not increase the incidence of rebleeding.

Transvenous embolization for an intraosseous clival arteriovenous fistula via a proper access route guiding a three-dimensional fusion image: illustrative case.

BACKGROUND: Intraosseous clival arteriovenous fistulas (AVFs), in which the shunt drains extracranially from the posterior and anterior condylar veins rather than from the cavernous sinus (CS), are rare. Targeting embolization of an intraosseous clival AVF is challenging because of its complex venous and skull base anatomy; therefore, a therapeutic strategy based on detailed preoperative radiological findings is required to achieve a favorable outcome. Here, the authors report the successful targeted embolization of an intraosseous clival AVF using an ingenious access route. OBSERVATIONS: A 74-year-old woman presented with left-sided visual impairment, oculomotor nerve palsy, and right facial pain. A fusion image of three-dimensional rotational angiography and cone-beam computed tomography revealed a left CS dural AVF and a right intraosseous clival AVF. The shunt flow of the clival AVF drained extracranially from the posterior and anterior condylar veins via the intraosseous venous route. Transvenous embolization was performed by devising suboccipital, posterior condylar, and intraosseous access routes. The symptoms resolved after the bilateral AVFs were treated. LESSONS: Accurate diagnosis and proper transvenous access based on detailed intraosseous and craniocervical venous information obtained from advanced imaging modalities are key to resolving intraosseous clival AVF.

Increased door-to-puncture time during off-duty hours results in poor treatment outcomes for acute ischemic stroke: A subanalysis of the K-NET registry.

BACKGROUND: For patients who undergo endovascular treatment for acute ischemic stroke, the total time for treatment may increase during off-duty hours leading to worse outcomes. The present study compared endovascular treatment outcomes for on-duty and off-duty hours and examined factors that could be responsible for the prolonged treatment of patients in a multicenter registry. METHODS: The study group comprised 1571 patients listed in the multicenter stroke registry (K-NET) who had undergone endovascular treatment between January 2018 and June 2020. The modified Rankin Scale (mRS), evaluated at 90 days after stroke onset, was utilized as the primary outcome. Patients were divided into on-duty and off-duty patients based on admission time. Multivariate logistic regression analysis was used to identify the independent factors that increased the time from admission to puncture during the off-duty period. RESULTS: The mean mRS score at 90 days after stroke onset was 2.9, similar in both on-duty and off-duty patients, with no significant difference (p = 0.77); however, significant differences were observed in time from door-to-puncture (74.7 vs. 88.8, p < 0.01). Additionally, the mRS score at 90 days worsened significantly for door-to-puncture time >60 min in the off-duty period. Multivariate logistic regression analysis revealed that a low National Institute of Health Stroke Scale (NIHSS) score, high pre-mRS score, posterior circulation, and diabetes were independent indicators of door-to-puncture time >60 min during the off-duty period. CONCLUSION: Door-to-puncture time >60 min during off-duty hours was associated with poor outcomes related to low NIHSS, high pre-mRS, posterior circulation, and diabetes.

Complications and outcomes of carotid artery stenting in high-risk cases.

OBJECTIVES: Carotid artery stenting is sometimes adapted for some at-risk cases; however, appropriate treatment timing with stroke onset is controversial. This study aims to identify factors that have an impact on complications and outcomes, especially in patients at high risk. MATERIALS AND METHODS: We examined the characteristics of 152 consecutive patients treated by carotid artery stenting between January 2018 and March 2022 and retrospectively analyzed the risk factors for complications and poor outcomes (modified-Rankin-Scale deterioration), such as patient background, carotid artery stenting risks (access route tortuosity, severe calcification, vulnerable plaque, estimated glomerular filtration rate <30 mL/min/1.73 m2, etc.), characteristics of the stenosis, details of treatment, and treatment timing. RESULTS: The average North American Symptomatic Carotid Endarterectomy Trial criteria score was 68.3% and the lesion length was 20.5±9.7mm. Among patients, 107 (70.4%) had a carotid artery stenting risk. In high-risk carotid artery stenting cases, symptomatic complications occurred in 32 (30.0%), and the 90-day modified Rankin scale score deteriorated in 15 cases (14.0%). Multivariate analysis showed that cases with triple antithrombotic therapy (p=0.003), stenting within 7 days (p=0.0032), and after 28+ days (p=0.0035) of stroke onset were independently associated factors for complications. CONCLUSIONS: This study showed that among risk factors, triple antithrombotic therapy in particular was a risk factor for perioperative complications. Carotid artery stenting for patients with stroke after 28 days of onset affects the prognosis. Therefore, although further study is warranted, waiting more than one month for treatment in patients requiring carotid artery stenting is a potential risk.

Efficacy and safety of thrombectomy for acute ischaemic stroke in patients with pre-stroke mRS scores of 2-3: Real-world evaluation from an open-label, prospective, multicentre, observational study.

BACKGROUND: This study assessed the efficacy and safety of thrombectomy for acute ischaemic stroke in a population with pre-stroke modified Rankin scale (mRS) scores of 2-3 using real-world data. METHODS: Our sample set included 2313 consecutive patients enrolled in the Kanagawa Registry of Intravenous and Endovascular Treatment of Acute Ischemic Stroke registry between January 2018 and June 2020 in 40 stroke centres in Kanagawa Prefecture, Japan. Patients treated with intravenous tissue plasminogen activator (t-PA), thrombectomy, or both were included. Patients with pre-stroke mRS scores of 4-5 and those treated only with intra-arterial thrombolysis were excluded. The primary outcome of this study was an mRS score of 0-3 at 90 days after onset to assess the efficacy of thrombectomy for pre-stroke disabled individuals. We performed multivariate logistic regression analyses to investigate independent factors for a 90-day mRS score of 0-3. We also performed nearest-neighbour within-calliper matching between thrombectomy and t-PA only. RESULTS: After excluding patients meeting the exclusion criteria, we analysed data of 2136 consecutive patients, of which 315 (14.7%) had pre-stroke disabilities (mRS score 2-3). A 90-day mRS score of 0-3 was achieved by 33.3% of patients with pre-stroke mRS scores of 2-3. According to multivariate analysis, the National Institutes of Health Stroke Scale (NIHSS) score was an independent factor. Furthermore, after propensity-score matching, thrombectomy showed considerable superiority for achieving a 90-day mRS score of 0-3. CONCLUSION: Intravenous t-PA and especially thrombectomy were safe and effective for the population with pre-stroke disabilities, particularly for patients with low NIHSS scores.

Combined Endovascular Antegrade and Direct Retrograde Carotid Artery Stenting for Chronic and Long Segment Common Carotid Artery Occlusion: Technical Note and Review of Literature.

Common carotid artery (CCA) occlusion (CCAO) is a rare cause of ischemic stroke and bypass surgery is the common treatment approach. However, safer alternatives should be developed to treat CCAO. A 68-year-old male was diagnosed with left-sided CCAO with decreased left visual acuity due to neck radiation therapy for laryngeal cancer. Recanalization therapy using a pull-through technique was initiated because cerebral blood flow progressively decreased during the follow-up period. First, after a short sheath was inserted into the CCA, the occluded CCA was retrogradely penetrated through the sheath. Second, a micro-guidewire was guided to the aorta from the femoral sheath where it was caught using a snare wire guided from the cervical sheath. Subsequently, the micro-guidewire was gently pulled out from the cervical sheath, penetrated the occluded lesion, and was secured to the femoral and cervical sheaths. Finally, the occluded lesion was dilated using a balloon, and the stent was placed. Five days postprocedure, the patient was discharged uneventfully and exhibited improved left visual acuity. In terms of reliable penetration of obstructive lesions and reduction of embolic and hemorrhagic complications, combined endovascular antegrade and direct retrograde carotid artery stenting is a versatile and minimally invasive treatment option for CCAO.

Scratching and Stretching the Shrunken Cranial Dura for Primary Closure.

BACKGROUND: At craniotomy, the dura shrinks due to the drying effect of illumination and air exposure, rendering its primary closure difficult. When the opening is narrow, it can be patched with autologous grafts. However, tissue harvesting and meticulous suturing take time. As the cost-effectiveness of using dural substitutes is poor, we developed a new technique that involves dural scratching for the primary closure of dural openings. METHODS: We applied our technique because in 53 adults who underwent supratentorial craniotomy we encountered difficulties with the primary closure of a dural opening 5 mm or less in width. With a scalpel, we placed several fine scratches parallel to the edge of the opening on the surface of the dura, taking care not to perforate the deep layer. This relieved dural tension and the tissue was stretched enough to permit closing with sutures. RESULTS: Our technique achieved primary dural closure in 46 of 53 patients (87%) who primarily had undergone narrow supratentorial craniotomies. The other 7 additionally required small autologous grafts to patch narrow residual openings at the intersection of the durotomy. There were no procedure-related complications such as cerebrospinal fluid leakage and persistent headache due to tension of the closed dura. CONCLUSIONS: Dural scratching is simple, safe, requires no special instrumentation, facilitates primary closure of the shrunken dura by stretching, and reduces the need for patch grafting.

Cerebral foreign body granulomas after mechanical thrombectomy: Two case reports and a review of the literature.

OBJECTIVES: A foreign body granuloma after an endovascular intervention is a rare complication. Some cases of foreign body granulomas, especially after coil embolization, have been reported. However, only four cases of foreign body granulomas after mechanical thrombectomy (MT) have previously been reported. The current study reports two cases of post-MT foreign body granulomas, including a biopsy-proven case. MATERIAL AND METHODS: Case 1: A 73-year-old woman presented with complete occlusion of the right middle cerebral artery. Cerebral angiography and MT were successfully performed with improvement in clinical symptoms. Left hemiparesis and a disturbance in attention appeared after discharge and progressed slowly. She was re-admitted to our hospital 120 days after cerebral infarction owing to foreign body granulomas diagnosed on biopsy. Case 2: A 78-year-old man presented with occlusion of the left cervical internal carotid artery and the left middle cerebral artery. Cerebral angiography, percutaneous transluminal angioplasty, and MT were successfully performed. On the 34th day, he experienced progressive consciousness disorder because of foreign body granulomas. Both cases were successfully treated with steroid therapy. RESULTS: MRI after steroid treatment showed the disappearance of most nodular lesions and improvement of the encephalopathy. CONCLUSIONS: The cause of the granuloma may be an allergic reaction to the hydrophilic polymers that peel from endovascular devices. Steroid therapy is an effective treatment; therefore, neurologists should consider this complication when neurological symptoms or signs on image appears or worsens. A reliable diagnosis is important for prompt treatment.

Visual suppression of vestibulo-ocular reflex in patients treated with carotid artery revascularization: A potential biomarker for cerebral perfusion.

BACKGROUND: Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are common treatments for ischemic stroke prevention in patients with carotid artery stenosis. However, the beneficial effects of CEA/CAS for cerebral hypoperfusion due to carotid artery stenosis have yet to be fully established. As dizziness is a common symptom in patients with carotid artery stenosis, we aimed to evaluate the effects of CEA/CAS on cerebral function in patients with carotid artery stenosis, using equilibrium function tests. METHODS: This prospective observational cohort study included 50 patients who had carotid artery stenosis and were scheduled to undergo CEA or CAS. Before CEA/CAS, we quantitatively evaluated the vestibulo-ocular reflex (VOR) and vestibular evoked myogenic potential (VEMP), as indicators of brainstem/inner ear functions related to balance, and visual suppression of VOR, as an indicator of cerebral control over the brainstem reflex related to balance. These were then compared with supratentorial cerebral blood flow (CBF). Changes in VOR, VEMP, visual suppression of VOR, CBF, and dizziness after CEA/CAS were also evaluated. RESULTS: The visual suppression rates of VOR correlated with supratentorial CBFs before CEA/CAS (correlation coefficient = 0.47, p = 0.003). The visual suppression rates of VOR (p < 0.001) and supratentorial CBFs (p = 0.003) were improved by CEA/CAS, while VOR and VEMP did not change. Symptoms of dizziness improved after CEA/CAS. CONCLUSIONS: Our results suggest that visual suppression of the VOR may be a novel and practical marker for the beneficial effects of CEA/CAS on supratentorial cerebral function.

Feasibility of Preoperative Magnetic Resonance Angiography/Black-Blood Magnetic Resonance Imaging/Computed Tomography Fusion Imaging Without Contrast Agent for Carotid Endarterectomy.

BACKGROUND: Preoperative identification of the carotid bifurcation (CB) location and plaque and stenosis distal end of the cervical internal carotid artery in relation to bony structures is essential for carotid endarterectomy (CEA). However, for patients with contrast contraindications, cervical 3-dimensional computed tomography angiography (3D-CTA) is unavailable. In this study, we created fusion images of magnetic resonance angiography (MRA), black-blood (BB) magnetic resonance imaging (MRI), and CT to determine if these noncontrast agent images are superior to 3D-CTA for preoperative CEA planning. METHODS: The fusion images showed vascular structures obtained by MRA, plaque observed by BB-MRI, and bone structures shown by CT. Spatial localization accuracy was verified by directly overlaying contrast-enhanced 3D-CTA images on the fusion images. We validated this technique in 50 patients with unilateral ICA stenosis, 28 of whom underwent CEA. The 2D-distance CB MRA-CTA (the 2D distance difference between CB MRA and CB CTA perpendicular to the long axis of the carotid artery) was measured. We also compared the findings of the fusion image regarding the CB location and plaque distal end with the operative findings. RESULTS: The median 2D distance CB MRA-CTA was 1 mm. CB MRA was located distal and proximal to CB CTA in 21and 29 patients, respectively. The CB location and fusion-image plaque were consistent with the intraoperative findings in all CEA patients. CONCLUSIONS: Fusion images created from MRA, BB-MRI, and noncontrast CT were feasible as an alternative to 3D-CTA for patients with contrast contraindications.

Pull-Force Generated by the Revolving High-speed Drill Shaft Results in Unexpected Tissue Wrapping Around the Shaft.

BACKGROUND: Despite holding soft tissue away from high-speed drills during surgery, tissue can unexpectedly wrap around the drill shaft. We performed experiments to examine what precipitates such mishaps. METHODS: In a windless environment, a Signature Drill System (Stryker) featuring a 4-mm diameter coarse diamond or cutting bit was placed parallel to a suspended strip of polypropylene. The distance between the end of the strip and the drill shaft or bits was 4 or 8 mm. In another experiment, we placed the drill horizontally 10 mm above the top of dry-ice fog. The maximum drill speed was 75,000 rpm, and the horizontal motion of the polypropylene strip and the vertical motion of the dry-ice fog were recorded by a video camera. RESULTS: In the experiments, the strip parallel to the vertical shaft and the dry-ice fog were pulled toward the shaft; the higher the revolving drill speed, the faster its motion. On the other hand, in experiments where the end of the strip was next to either bit, no such motion was observed. CONCLUSIONS: The pulling force generated by revolving high-speed drill shafts may result in tissue wraparound even when soft tissue is held away from the shaft.

Using a Carpenter's Square to Localize Narrow or Multilayered Chronic Subdural Hematomas Diagnosed on Computed Tomography.

BACKGROUND: Chronic subdural hematomas (CSDHs) with narrow or multilayered hematomas must be accurately localized for burr hole drainage. We present a simple alternative localization method using conventional computed tomography (CT) scans acquired for the initial diagnosis and a commercially available carpenter's square (CS). METHODS: Using our novel method, we localized 77 narrow or multilayered CSDHs. A single burr hole site on the thickest portion of narrow hematomas or on the site allowing access to both the isolated superficial layer and the deep layer of multilayered hematomas was identified on axial CT images; the image was parallel to the orbitomeatal line (OML). On the target CT slice, the level from the OML and from the surface of the forehead to the intended burr hole (sagittal distance) was measured. The OML and the level of the CT target slice were marked using the CS. Then, the CS was placed at the marked target level; the 2 edges of the CS were situated on the frontal and temporal scalp and parallel to the OML and the sagittal line. The sagittal distance was then marked. RESULTS: All burr holes reached the CSDHs. The mean deviation of the burr holes was 4.7 mm inferior and 1.4 mm anterior to the intended site. In 65 instances (84.4%), a deviation within 10 mm was observed in both the superoinferior and the anteroposterior directions. CONCLUSIONS: Our simple and inexpensive method can localize narrow or multilayered CSDHs with acceptable accuracy and increases the efficiency of routine clinical work.

Nonsurgical treatment of cerebral ischemia associated with ACTA2 cerebral arteriopathy: a case report and literature review.

Mutations in ACTA2 gene can lead to multisystemic smooth muscle dysfunction, including cerebrovascular disease. Treatment strategies for this rare entity remain controversial, and patients are at increasing risk of neurological sequelae. We herein present the case of an 11-year-old boy previously diagnosed with an ACTA2 gene mutation who developed repetitive transient ischemic attacks and treated with bosentan, an oral endothelin receptor antagonist. Magnetic resonance imaging revealed bilateral, periventricular white matter T2 hyperintensities, and magnetic resonance angiography identified several abnormalities including fusiform dilatation in the proximal segments of internal cerebral arteries, together with followed by terminal segmental stenosis. The distal branches showed a markedly straightened course with no increase in lenticulostriate collaterals. Magnetic resonance imaging also revealed an increase in the number and size of large periventricular white matter lesions located in the left frontal lobe with the progression of ischemic symptoms. Instead of revascularization surgery, the administration of bosentan was started due to the high risk of perioperative ischemic sequelae. After bosentan initiation, the patient's repetitive episodes of cerebral ischemia ceased, and there has been no increase in the number of white matter lesions for 7 years. Bosentan might be beneficial for treating cerebral ischemia associated with ACTA2 cerebral arteriopathy by maintaining the dilatation of stenotic vessels and adequate systemic blood flow and should be considered before performing revascularization surgery.

Renal Dysfunction is the Strongest Prognostic Factor After Carotid Artery Stenting According to Real-World Data.

PURPOSE: Through the progression of devices, the adaptation of carotid artery stenting (CAS) has been expanded according to the non-inferiority of CAS for carotid endarterectomy reported by several randomized control trials. To maintain favorable outcomes, identifying prognostic factors is essential for optimizing treatment indications and periprocedural management. This study focused on the prognostic factors of CAS using real-world data. METHODS: This retrospective multicenter cohort study aimed to identify the prognostic factors after CAS using real-world data from the stroke registry of Yokohama (STrOke Registry of Yokohama; STORY) from January 1, 2018 to May 31, 2021. Patient characteristics, procedural factors, complications, and prognoses were collected using medical records. RESULTS: Data from 107 patients were enrolled in this study after excluding those with insufficient data (2 cases). The mean participant age was 74.9±8.2 years, and 66 patients (61.7%) were symptomatic. Symptomatic lesions were a significant prognostic factor in the overall analysis (p=0.003). A multivariate analysis showed that the estimated glomerular filtration rate (eGFR) (odds ratio: 1.11, p=0.003) and staged CAS (odds ratio: 38.9, p=0.04) were independent prognostic factors. The odds ratio and relative risk of mRS deterioration when eGFR was under 49 mL/min/1.73 m2 compared with when eGFR was above 49 mL/min/1.73 m2 were 5.2 and 3.74, respectively. CONCLUSIONS: In this real-world multicenter study, we established independent prognostic factors for CAS using high totality data. For patients with symptomatic lesions and low eGFR (≤49 mL/min/1.73 m2), indication for treatment should be considered strictly.

Fatal recurrent ischemic stroke caused by vertebral artery stump syndrome.

BACKGROUND: Vertebral artery stump syndrome (VASS) develops into recurrent posterior circulation ischemic stroke after ipsilateral vertebral artery (VA) occlusion at its origin. CASE DESCRIPTION: The patient was a 46-year-old man with the right posterior cerebral artery occlusion. We used a recombinant tissue plasminogen activator (rt-PA) and then performed mechanical thrombectomy using a stent retriever. Angiography revealed left VA occlusion and stagnant flow to the left VA from the right deep cervical artery; therefore, we diagnosed VASS. Within 24 h of the rt-PA injection, the symptoms had dramatically improved, and so we avoided additional antithrombotic agents. Only 13 h later, the patient developed a basilar artery occlusion and died in spite of a repeated mechanical thrombectomy. CONCLUSION: Vigilance against early (and sometimes fatal) recurrent stroke induced by VASS is required.

Aneurysms Arising from Persistent Arteries in the Vertebrobasilar Paramedian Longitudinal Axis: Two Case Reports.

A 50-year-old man and a 69-year-old woman with consciousness disturbance were diagnosed to have suffered from subarachnoid hemorrhage (SAH) involving the posterior fossa. In both cases, the initial 3D CT angiogram failed to reveal the SAH source in the vertebrobasilar system. Delayed 3D rotational angiography revealed aneurysms on unfamiliar aberrant arteries. One was a dissecting aneurysm located between the proximal part of the posterior inferior cerebellar artery and the distal part of the intracranial vertebral artery. It was trapped and resected; the patient subsequently presented with lateral medullary symptoms. The other aneurysm was between the distal posterior and the distal anterior inferior cerebellar artery. It was successfully embolized; there were no complications. We think that the aberrant aneurysm-harboring vessels encountered in these two patients were primitive arteries on or adjacent to the vertebrobasilar paramedian longitudinal axis and that they persisted past the embryologic stage. Such aneurysms arising from unfamiliar persistent arteries beside the brainstem are extremely rare but must be considered when the SAH source is not detected in the trunk of the vertebrobasilar system.

The Relationships between Anatomical Factors and Treatment Procedures for the Endovascular Treatment of Anterior Communicating Artery Aneurysms.

Objective: Endovascular treatment of anterior communicating artery aneurysms is difficult due to their complex anatomical structure. We retrospectively analyzed the relationships among the anatomical features, initial microcatheter positions, and initial occlusion outcomes. Methods: In all, 66 cases were treated at our hospital. We investigated the relationships among the anatomical features of the aneurysm and A1 segment of the anterior cerebral artery (ACA), treatment procedures, and initial occlusion outcomes. We divided the initial microcatheter positions into greater and lesser curvatures based on the curvature from A1 to the aneurysm, and evaluated the outcomes. Results: In total, 54 out of 66 patients (82%) achieved complete obliteration (CO) or had residual neck (RN) aneurysms, and 12 had residual aneurysms (RAs: 18%). Neck diameters and superior position aneurysms were correlated with initial occlusion outcomes in the multivariate analysis. The relationship between initial occlusion outcomes and initial microcatheter positions in superior position aneurysms (37 patients) was then examined. Eleven out of 26 patients (42.3%) had residual aneurysms at the greater curvature microcatheter position, whereas no residual aneurysms were detected at the lesser curvature microcatheter position. The A1 angle was not correlated with the outcomes. Conclusion: Wide-necked aneurysms and superior position aneurysms were identified as factors leading to incomplete occlusion in the endovascular treatment of anterior communicating artery aneurysms. The microcatheter position at the greater curvature in superior position aneurysms was a factor for incomplete occlusion. This suggests that guiding the microcatheter to the lesser curvature position of A1 is important in the treatment of superior position aneurysms.