Safety of Apixaban Monotherapy for Non-Valvular Atrial Fibrillation-Related Acute Stroke with Intra-/Extracranial Artery Stenosis.

INTRODUCTION: We investigated whether apixaban is safe for the prevention of further adverse events in non-valvular atrial fibrillation (NVAF) patients with intra-/extracranial artery stenosis (Stenosis group) compared with acute large vessel occlusion without intra-/extracranial artery stenosis (No stenosis group). We also examined whether combination therapy using apixaban and antiplatelet is safe. METHODS: ALVO (Apixaban on clinical outcome of patients with Large Vessel Occlusion [LVO] or stenosis) was a historical and prospective multicenter registry at 38 centers in Japan. Patients with NVAF and acute LVO or stenosis who received apixaban within 14 days after onset were included. We conducted the post hoc analysis using the ALVO dataset. We compared patients with stenosis versus those without stenosis in terms of the primary outcome, which was defined as a composite of all-cause death, major bleeding events, and ischemic events 365 days after onset. RESULTS: Of the 662 patients, 54 (8.2%) patients were classified into the Stenosis group, and 104 patients of the total (16%) reached the primary outcome. The cumulative incidence of primary outcome was not significantly different between the No stenosis and the Stenosis groups (hazard ratio [HR] 1.2, 95% confidence interval [CI]: 0.64-2.4; p = 0.52). Even after adjustment for predictive clinical variates, no significant difference in the primary endpoint between the No stenosis and the Stenosis groups was shown (adjusted HR 1.2, 95% CI: 0.59-2.5; p = 0.60). Fifty patients (7.6%) used an antiplatelet with apixaban. Among the Stenosis group patients, the cumulative incidence of the primary outcome was significantly higher among patients treated with an antiplatelet and apixaban (HR 3.5, 95% CI: 1.0-12; p = 0.048). CONCLUSION: Apixaban monotherapy appears safe for the prevention of further adverse events in the Stenosis group patients similar to the No stenosis group patients. Concomitant use of an antiplatelet might not be favorable in patients with stenosis.

A human T-lymphotropic virus-1 carrier who developed progressive multifocal leukoencephalopathy following immunotherapy for sarcoidosis: a case report.

BACKGROUND: Progressive multifocal leukoencephalopathy (PML) is a devastating demyelinating disorder of the central nervous system caused by opportunistic infection of the JC virus (JCV). CASE PRESENTATION: A 58-year-old Japanese woman was admitted to our hospital for aphasia. She had a 5-year history of untreated sarcoidosis and was a human T cell lymphotropic virus-1 (HTLV-1) carrier. Serum angiotensin-converting enzyme, soluble interleukin-2 receptor, lysozyme, and calcium levels were elevated. JCV-DNA was not detected in cerebrospinal fluid by PCR testing. Skin biopsy revealed noncaseating granuloma formation. Bilateral multiple nodular lesions were present on chest X-ray. Brain magnetic resonance imaging showed left frontal and temporal lesions without gadolinium enhancement. As we suspected that systemic sarcoidosis had developed into neurosarcoidosis, we started steroid and infliximab administration. After treatment, the chest X-ray and serum abnormalities ameliorated, but the neurological deficits remained. At 1 month after immunotherapy, she developed right hemiparesis. Cerebrospinal fluid was positive for prototype (PML-type) JCV on repeated PCR testing. Brain biopsy revealed demyelinating lesions with macrophage infiltration, atypical astrocytes, and JCV antigen-positive cells. We diagnosed her with PML and started mefloquine, leading to partial remission. CONCLUSIONS: Sarcoidosis and HTLV-1 infection both affect T cell function, especially CD4+ T cells, and may developped the patient's PML. The comorbidity of sarcoidosis, PML, and HTLV-1 infection has not been reported, and this is the world's first report of PML associated with HTLV-1 infection and sarcoidosis.

A rare adult case of asymptomatic double aortic arch accompanied by the right vertebral artery directly originating from the aortic arch.

INTRODUCTION: A double aortic arch (DAA) is a rare congenital vascular anomaly. No case of DAA with a direct aortic origin of the right vertebral artery (VA) has been reported in adults. Here, we report a rare case of an asymptomatic DAA accompanied by the right VA directly originating from the right aortic arch in an adult. CASE PRESENTATION: A DAA and right VA directly originating from the right aortic arch were identified in a 63-year-old man using digital subtraction angiography and computed tomography angiography. The patient underwent digital subtraction angiography for evaluation of an unruptured cerebral aneurysm. Intraprocedural selection of vessels branching from the aorta with the catheter was difficult. To confirm the bifurcation of the aorta, aortography was performed, which revealed a DAA. Following digital subtraction angiography, computed tomography angiography was performed, which showed that the right VA originated directly from the right aortic arch. The trachea and esophagus were located in the vascular ring of the DAA; however, they were not compressed by the aorta. This was consistent with the lack of symptoms related to the DAA. CONCLUSIONS: This is the first adult case of an asymptomatic DAA with an unusual origin of the VA. A rare asymptomatic vascular anomaly, such as a DAA, can be incidentally identified using angiography.

Rare anastomosis between the bilateral internal carotid arteries via the recurrent arteries branching from the first segment of the ophthalmic artery.

Although anastomoses between the arterial branches arising from the internal carotid artery (ICA) can develop as collateral pathways between the bilateral ICAs in cases of dysgenesis of the ICA, anastomosis of the recurrent arteries branching from the first segment of the ophthalmic artery (OphA) has not been described. Herein, we report two cases of this rare anastomosis. In a 36-year-old man with left segmental dysgenesis of the ICA, an anastomosis between the bilateral ICAs developed around the sella turcica. In a 39-year-old woman with dysgenesis of the bilateral distal ICAs, an anastomosis between the superior hypophyseal trunk and bilateral ICAs was identified. The anastomoses in both cases were also supplied by recurrent arteries branching from the first segment of the OphAs. This is the first report describing recurrent arteries from the OphAs that form the anastomosis between bilateral ICAs.

Gadolinium-enhanced MR improved motion sensitized driven equilibrium (iMSDE) for intracranial vessel imaging in giant cell arteritis.

BACKGROUND: Giant cell arteritis (GCA) generally affects extracranial large and medium-sized vessels. It rarely causes intracranial vessel stenosis, presenting as cerebral infarction (CI). Consequently, accurate diagnosis of CI induced by GCA is often challenging. Improved motion-sensitized driven-equilibrium (iMSDE) is one of the advanced high-resolution magnetic resonance (MR) vessel wall imaging techniques that enables direct visualization of the vessel wall because of a strong reduction in blood flow artifacts, leading to higher quality images. Herein, we effectively used gadolinium-enhanced MR iMSDE imaging to diagnose a patient presenting with recurrent CI due to right intracranial internal carotid artery (ICA) stenosis as GCA. CASE DESCRIPTION: A 64-year-old man with polymyalgia rheumatica for several years and who had experienced CI due to moderate intracranial ICA stenosis one year ago, presented to the emergency room with dysarthria and left hemiparesis. Diffusion-weighted MR imaging showed high signals in the right centrum ovale, and MR angiography revealed severe stenosis of the right intracranial ICA. Gadolinium-enhanced MR iMSDE imaging showed marked concentric enhancement in the vessel wall of the right stenosed ICA, which led to a definitive diagnosis of GCA via biopsy from the right superficial temporal artery. The patient's symptoms gradually improved after initiation of steroid treatment. Three months later, gadolinium-enhanced MR iMSDE imaging revealed improvement in the contrast enhancement in the vessel wall and vascular stenosis. CONCLUSION: Gadolinium-enhanced MR iMSDE imaging is useful to diagnose and evaluate GCA with intracranial vessel involvement.

The impact of the approval of prothrombin complex concentrates for vitamin K antagonist-related intracerebral hemorrhage: A retrospective study.

OBJECTIVES: This study aimed to determine the impact of the approval of prothrombin complex concentrates on the treatment of vitamin K antagonist-related intracerebral hemorrhage. MATERIALS AND METHODS: We retrospectively studied all patients with vitamin K antagonist-related intracerebral hemorrhage treated with prothrombin complex concentrate at our institutes between January 2010 and June 2021. Before approval, prothrombin complex concentrate was administered as either 500 or 1000 IU at the physician's discretion (previous dose group). After approval, we adopted the manufacturer's recommended regimen (recommended dose group). The primary outcome was post-administration international normalized ratio. Secondary outcomes were the amount of prothrombin complex concentrate administered and proportion of post-administration international normalized ratio <1.5, hematoma expansion, thrombotic events within 30 days, modified Rankin scale 0-3 at discharge, and in-hospital mortality. RESULTS: Thirty-two and 19 patients in the previous and recommended dose groups, respectively, were included. The post-administration international normalized ratio significantly differed between groups. The prothrombin complex concentrate dose and proportion of patients achieving post-administration international normalized ratio <1.5 were significantly higher in the recommended dose group than in the previous dose group (1500 IU vs. 500 IU, p<0.001 and 100% vs. 68%, p = 0.008). The proportions of hematoma expansion, thromboembolic events, modified Rankin scale 0-3, and mortality did not differ between groups. CONCLUSION: After prothrombin complex concentrate approval, prothrombin time-international normalized ratio correction was more effective with a significant increase in the prothrombin complex concentrates dose for vitamin K antagonist-associated intracerebral hemorrhage; however, there was no apparent difference in clinical outcomes.

Factors associated with the new appearance of cerebral microbleeds after endovascular treatment for unruptured intracranial aneurysms.

PURPOSE: Endovascular treatment of unruptured intracranial aneurysms may increase cerebral microbleeds (CMBs) in postprocedural T2*-weighted MRIs, which may be a risk for future intracerebral hemorrhage. This study examined the characteristics of postprocedural CMBs and the factors that cause their increase. METHODS: The patients who underwent endovascular treatment for unruptured intracranial aneurysms from April 2016 to February 2018 were retrospectively analyzed. Treatment techniques for endovascular treatment included simple coiling, balloon-assisted coiling, stent-assisted coiling, or flow diverter placement. To evaluate the increase in CMBs, a head MRI including diffusion-weighted imaging and T2*-weighted MRIs was performed on the preprocedural day; the first postprocedural day; and at 1, 3, and 6 months after the procedure. RESULTS: Among the 101 aneurysms that were analyzed, 38 (37.6%) showed the appearance of new CMBs. In the multivariate analysis examining the causes of the CMB increases, chronic kidney disease, a higher number of preprocedural CMBs, and a higher number of diffusion-weighted imaging-positive lesions on the first postprocedural day were independent risk factors. Furthermore, a greater portion of the increased CMBs was found in cortical and subcortical lesions of the treated vascular perfusion area within 1 month after the procedure. CONCLUSION: In endovascular treatment for unruptured intracranial aneurysms, CMBs tended to increase in patients with small vessel disease before the procedure, and it was also implicated in hemorrhagic changes after periprocedural microinfarction.

Deep Learning-Derived High-Level Neuroimaging Features Predict Clinical Outcomes for Large Vessel Occlusion.

Background and Purpose- For patients with large vessel occlusion, neuroimaging biomarkers that evaluate the changes in brain tissue are important for determining the indications for mechanical thrombectomy. In this study, we applied deep learning to derive imaging features from pretreatment diffusion-weighted image data and evaluated the ability of these features in predicting clinical outcomes for patients with large vessel occlusion. Methods- This multicenter retrospective study included patients with anterior circulation large vessel occlusion treated with mechanical thrombectomy between 2013 and 2018. We designed a 2-output deep learning model based on convolutional neural networks (the convolutional neural network model). This model employed encoder-decoder architecture for the ischemic lesion segmentation, which automatically extracted high-level feature maps in its middle layers, and used its information to predict the clinical outcome. Its performance was internally validated with 5-fold cross-validation, externally validated, and the results compared with those from the standard neuroimaging biomarkers Alberta Stroke Program Early CT Score and ischemic core volume. The prediction target was a good clinical outcome, defined as a modified Rankin Scale score at 90-day follow-up of 0 to 2. Results- The derivation cohort included 250 patients, and the validation cohort included 74 patients. The convolutional neural network model showed the highest area under the receiver operating characteristic curve: 0.81±0.06 compared with 0.63±0.05 and 0.64±0.05 for the Alberta Stroke Program Early CT Score and ischemic core volume models, respectively. In the external validation, the area under the curve for the convolutional neural network model was significantly superior to those for the other 2 models. Conclusions- Compared with the standard neuroimaging biomarkers, our deep learning model derived a greater amount of prognostic information from pretreatment neuroimaging data. Although a confirmatory prospective evaluation is needed, the high-level imaging features derived by deep learning may offer an effective prognostic imaging biomarker.

Modified diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score including deep white matter lesions predicts symptomatic intracerebral hemorrhage following intravenous thrombolysis.

The Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is widely used for the assessment of early ischemic changes (EICs) before thrombolysis. However, for symptomatic intracerebral hemorrhage (sICH) following intravenous recombinant tissue plasminogen activator (rt-PA), the prediction abilities of CT-ASPECTS, diffusion-weighted imaging (DWI)-ASPECTS, and DWI-ASPECTS including EICs in deep white matter (DWI-ASPECTS + W) are unclear. We investigated associations between each score and sICH following intravenous rt-PA. Data from consecutive patients who received intravenous rt-PA for acute ischemic stroke from 2005 to 2015 in four hospitals were retrospectively screened. We included data from patients who had undergone both CT and magnetic resonance imaging before thrombolysis and without evidence of posterior circulation stroke. We analyzed the ability of CT-ASPECTS, DWI-ASPECTS, and DWI-ASPECTS + W to predict sICH, accompanied by an increase in the National Institutes of Health Stroke Scale (NIHSS) score of ≥ 4 within the initial 36 h. Of 455 patients (273 men, median 75 years old), sICH occurred in 15 patients (3.3%). Receiver operating characteristics curve analysis showed that the optimal cut-offs of CT-ASPECTS, DWI-ASPECTS, and DWI-ASPECTS + W for predicting sICH were ≤ 9 (sensitivity 60.0%, specificity 59.8%, c-statistic 0.625), ≤ 6 (sensitivity 53.3%, specificity 80.9%, c-statistic 0.718), and ≤ 8 (sensitivity 86.7%, specificity 55.9%, c-statistic 0.756), respectively. A DWI-ASPECTS + W of ≤ 8 was independently associated with sICH (odds ratio 5.21, 95% confidence interval 1.30-35.31) after adjustment for pretreatment with antithrombotic agents, pretreatment NIHSS score, and large artery occlusions. DWI-ASPECTS + W predicted sICH in patients with acute anterior circulation stroke receiving intravenous rt-PA.

Differences between predictive factors for early neurological deterioration due to hemorrhagic and ischemic insults following intravenous recombinant tissue plasminogen activator.

Early neurological deterioration (END) following intravenous recombinant tissue plasminogen activator (rt-PA) treatment is a serious clinical event that can be caused by hemorrhagic or ischemic insult. We investigated the differences in predictive factors for END due to hemorrhagic and END due to ischemic insults. Consecutive patients from four hospitals who received 0.6 mg/kg intravenous rt-PA for acute ischemic stroke were retrospectively recruited. END was defined as a National Institutes of Health Stroke Scale (NIHSS) score ≥ 4 points within 24 h compared with baseline. END was classified into those due to hemorrhagic (ENDh) or ischemic (ENDi) insult based on computed tomography (CT) or magnetic resonance imaging. Risk factors associated with ENDh and ENDi were investigated by comparison with non-END cases. A total of 744 patients (452 men, median 75 years old) were included. END was observed in 79 patients (10.6%), including 22 ENDh (3.0%) and 57 ENDi (7.7%), which occurred within a median of 7 h after treatment. Multivariate analyses showed that higher pretreatment NIHSS score (odds ratio [OR] 1.06, 95% confidence interval [CI] 1.00-1.13) and pretreatment with antiplatelets (OR 2.84, 95% CI 1.08-7.72) were associated with ENDh. Extensive early ischemic change (Alberta Stroke Program Early CT Score ≤ 7 on CT or ≤ 6 on diffusion-weighted imaging; OR 2.80, 95% CI 1.36-5.64) and large artery occlusions (OR 3.09, 95% CI 1.53-6.57) were associated with ENDi. Distinct factors were predictive for the END subtypes. These findings could help develop preventative measures for END in patients with the identified risk factors.

Predicting Clinical Outcomes of Large Vessel Occlusion Before Mechanical Thrombectomy Using Machine Learning.

Background and Purpose- The clinical course of acute ischemic stroke with large vessel occlusion (LVO) is a multifactorial process with various prognostic factors. We aimed to model this process with machine learning and predict the long-term clinical outcome of LVO before endovascular treatment and to compare our method with previously developed pretreatment scoring methods. Methods- The derivation cohort included 387 LVO patients, and the external validation cohort included 115 LVO patients with anterior circulation who were treated with mechanical thrombectomy. The statistical model with logistic regression without regularization and machine learning algorithms, such as regularized logistic regression, linear support vector machine, and random forest, were used to predict good clinical outcome (modified Rankin Scale score of 0-2 at 90 days) with standard and multiple pretreatment clinical variables. Five previously reported pretreatment scoring methods (the Pittsburgh Response to Endovascular Therapy score, the Stroke Prognostication Using Age and National Institutes of Health Stroke Scale index, the Totaled Health Risks in Vascular Events score, the Houston Intra-Arterial Therapy score, and the Houston Intra-Arterial Therapy 2 score) were compared with these models for the area under the receiver operating characteristic curve. Results- The area under the receiver operating characteristic curve of random forest, which was the worst among the machine learning algorithms, was significantly higher than those of the standard statistical model and the best model among the previously reported pretreatment scoring methods in the derivation (the area under the receiver operating characteristic curve were 0.85±0.07 for random forest, 0.78±0.08 for logistic regression without regularization, and 0.77±0.09 for Stroke Prognostication using Age and National Institutes of Health Stroke Scale) and validation cohorts (the area under the receiver operating characteristic curve were 0.87±0.01 for random forest, 0.56±0.07 for logistic regression without regularization, and 0.83±0.00 for Pittsburgh Response to Endovascular Therapy). Conclusions- Machine learning methods with multiple pretreatment clinical variables can predict clinical outcomes of patients with anterior circulation LVO who undergo mechanical thrombectomy more accurately than previously developed pretreatment scoring methods.

Temporal Trends in Clinical Characteristics and Door-to-Needle Time in Patients Receiving Intravenous Tissue Plasminogen Activator: A Retrospective Study of 4 Hospitals in Japan.

BACKGROUND: Intravenous recombinant tissue plasminogen activator (rt-PA) has become a common treatment for acute ischemic stroke and has highly time-dependent benefits. We aimed to clarify temporal trends regarding the frequency and characteristics of patients receiving rt-PA and explore factors associated with door-to-needle time (DNT) in Japanese emergency hospitals. METHODS: Consecutive patients who received intravenous rt-PA for acute ischemic stroke from October 2005 to December 2015 were retrospectively registered from 4 hospitals. Temporal trends in the frequency and characteristics of patients receiving rt-PA and factors associated with DNT were investigated. RESULTS: A total of 750 patients, including 688 (420 men, median 75 years old) with out-of-hospital stroke, were registered. The frequency of patients receiving intravenous rt-PA for acute ischemic stroke continuously increased from 1.8% in 2005 to 9.5% in 2015. The proportion of patients who were elderly or had prestroke disability increased over time, while pretreatment stroke severity declined. The DNT gradually decreased (median 105 minutes in 2005, 61 minutes in 2015). According to multivariate regression analysis with correction for multiple comparisons, activation of a code stroke system (standardized partial regression coefficient (ß) -.50, P < .001, q < .001), onset-to-door time (ß -.15, P < .001, q < .001), pretreatment with antithrombotic agents (ß .12, P < .001, q = .001), and year of treatment (ß .11, P = .007, q = .011) were associated with DNT. CONCLUSIONS: Intravenous rt-PA was widely adopted in Japanese emergency hospitals. Characteristics of patients receiving intravenous rt-PA have changed over the past decade. Several factors, including the year of treatment, were associated with DNT, which has shortened over time.

International multicentre validation of the arteriovenous malformation-related intracerebral haemorrhage (AVICH) score.

OBJECTIVE: The recently published arteriovenous malformation-related intracerebral haemorrhage (AVICH) score showed better outcome prediction for patients with arteriovenous malformation (AVM)-related intracerebral haemorrhage (ICH) than other AVM or ICH scores. Here we present the results of a multicentre, external validation of the AVICH score. METHODS: All participating centres (n=11) provided anonymous data on 325 patients to form the Spetzler-Martin (SM) grade, the supplemented SM (sSM) grade, the ICH score and the AVICH score. Modified Rankin score (mRS) at last follow-up (mean 25.6 months) was dichotomized into favourable (mRS 0-2, n=210) and unfavourable (mRS 3-6;n=115). Univariate and AUROC analyses were performed to validate the AVICH score. RESULTS: Except nidus structure and AVM size, all single parameters forming the SM, sSM, ICH and AVICH score and the scores itself were significantly different between both outcome groups in the univariate analysis. The AVICH score was confirmed to be the highest predictive outcome score with an AUROC of 0.765 compared with 0.705 for the ICH score and 0.682 for the sSM grade. CONCLUSION: The multicentre-validated AVICH score predicts clinical outcome superior to pre-existing scores. We suggest the routine use of this score for future clinical outcome prediction and in clinical research. TRIAL REGISTRATION NUMBER: NCT02920645.

Reversible striatal hypermetabolism in chorea associated with moyamoya disease: a report of two cases.

BACKGROUND: The pathophysiological mechanism of chorea as a presentation of pediatric moyamoya disease remains unknown, although ischemia is suspected as a likely cause. The authors describe two cases of pediatric moyamoya disease, both of which presented with hemichorea in the stable phase after successful bypass surgery. CLINICAL PRESENTATION: Cerebral blood flow was almost normal in one case and decreased in the basal ganglia and watershed area in the other case due to infarcts occurring before surgery. In both cases, 18F-fluorodeoxyglucose positron emission tomography revealed elevated glucose metabolism in the corresponding side of the striatum, which reverted to normal after recovery from chorea. Magnetic resonance angiography revealed a dilated and extended lenticulostriate artery at the exact site of the hypermetabolic lesion.

Follow-up after undersized dilatation of targeted lesions in carotid artery stenting.

BACKGROUND AND PURPOSE: We assessed whether intentional undersized dilatation of targeted lesions during carotid artery stenting (CAS) carried a higher risk of in-stent restenosis (ISR) and correlation to subsequent ischemic stroke in qualifying arteries in the follow-up period. METHODS: Consecutive patients undergoing CAS between April 2003 and May 2010 were retrospectively reviewed. The use of a filter device as a distal embolic protection device (EPD) was first approved by Japanese governmental health insurance in April 2008; previously, transient balloon occlusion was used off-label. Until March 2008 (Group A), the target diameter of balloon dilatation was 80-100% of the normal vessel diameter just distal to the stenotic lesion. Moderately undersized dilatation (70-80% of the normal vessel diameter) using the distal EPD was adopted in April 2008 (Group B) in an attempt to reduce the amount of released plaque debris. RESULTS: We analyzed 132 CAS procedures (125 patients) in Group A and 53 CAS procedures (52 patients) in Group B. The mean follow-up period was 35.4 months (35.3 months in Group A and 36.0 months in Group B). Eight lesions (4.3%; 7 in Group A and 1 in Group B) developed ISR. None of the patients had symptomatic ISR, and ISR did not increase in Group B (odds ratio, 0.34; 95% confidence interval, 0.04-2.86; p = 0.32). CONCLUSIONS: Undersized dilatation of targeted lesions did not increase the risk of developing ISR, and we suggest it as a viable treatment option to prevent ischemic events during CAS.

Endovascular treatment for intracranial vertebrobasilar artery stenosis.

PURPOSE: We describe our experience with endovascular treatment for symptomatic intracranial vertebrobasilar artery stenosis. MATERIALS AND METHODS: Forty-four patients with intracranial vertebrobasilar artery stenosis (37 vertebral arteries, 7 basilar arteries) were treated with endovascular surgery. Indication criteria for the treatment were (1) medically refractory symptomatic patients; (2) angiographic stenosis of more than 60 %; and (3) short lesion (<15 mm). Under local anesthesia, balloon angioplasty was first performed in all patients. Stenting was performed only in cases with insufficient dilatation, dissection, or restenosis after balloon angioplasty. The degree of stenosis, which was 83 % before treatment, was reduced to 23 % after treatment. The rate of stroke and death within 30 days was 2.3 %. Nine patients (20.5 %) developed restenosis within 6 months. Of these, four patients were symptomatic. All symptomatic patients with restenosis were successfully treated with balloon angioplasty or stenting. CONCLUSION: Endovascular treatment for vertebrobasilar artery stenoses is feasible and safe in selected patients. Restenosis may be an important cause of recurrent stroke. Therefore, close clinical and neuroradiological follow-ups are essential for patients treated with endovascular surgery to improve long-term results.

Unexpected coil mass migration during transvenous embolization of a dural arteriovenous fistula resolved with guidewire-assisted snaring technique.

Endovascular embolization is a standard treatment for dural arteriovenous fistulas (dAVFs). Although it is considered relatively safe, intraoperative and postoperative complications can occur. Herein, a rare case of unexpected coil mass migration requiring a retrieval procedure during sinus occlusion for a transverse-sigmoid sinus dAVF (TSdAVF) is described. An 83-year-old man presented with worsening decline in cognitive function. Magnetic resonance angiography showed a TSdAVF. Since his symptoms seemed to be a result of the TSdAVF, transvenous embolization preserving the normal cranial venous circulation was planned. During sinus occlusion, including embolization of the shunted pouch of the TSdAVF, unexpected migration of the coil mass to the confluence of the superior sagittal sinus and the transverse sinus occurred. The migrated coil mass impeded venous circulation in the superior sagittal sinus. Since the presence of the coil mass at the confluence could have had catastrophic sequelae, the coil mass was retrieved using a guidewire-assisted snaring technique. Sinus occlusion was subsequently completed with repositioning of the coil mass at the target site. The TSdAVF resolved, with no recurrence confirmed for 1 year. Clinicians should be aware that coil mass migration can unexpectedly occur during sinus occlusion performed for treatment of a TSdAVF. The guidewire-assisted snaring technique might be effective in resolving this intraoperative complication.

An extremely rare complication during carotid artery stenting using a Wallstent: Migration of a stent holder of a Carotid Wallstent.

BACKGROUND: Carotid artery stenting (CAS) is an established treatment for internal carotid artery stenosis (ICS). The Carotid Wallstent is commonly used as a stent device in CAS procedures. Rare complications associated with the use of the Carotid Wallstent in CAS procedures include delayed shortening and incomplete stent expansion due to displacement of a marker ring. However, there have been no previous reports of a stent holder becoming unpredictably detached from a Carotid Wallstent during a procedure, requiring the additional deployment of another Carotid Wallstent. CASE PRESENTATION: The case of a 72-year-old man with progressive ICS is described. Since the ICS was resistant to medical treatment, CAS was planned to prevent ischemic events. During the procedure, a Mo.Ma Ultra and a carotid guardwire were used for proximal and distal protection, respectively. Following the introduction of those protective devices, a Carotid Wallstent was deployed at the stenotic lesion of the ICS. After the deployment of the Carotid Wallstent, a stent holder unpredictably detached was identified in the lumen of the Carotid Wallstent. Since it was impossible to mechanically retrieve the detached stent holder, another Carotid Wallstent was deployed to trap the substance. Postoperatively, the substance was identified as a stent holder of the first Carotid Wallstent. CONCLUSION: This is the first report of an extremely rare complication concerning a Carotid Wallstent in CAS.

Lumbar Subarachnoid-Peritoneal Shunting Deteriorates Superficial Siderosis Associated with a Dural Defect.

Superficial siderosis is a disease in which hemosiderin is deposited under the leptomeninges and subpial layers of hindbrain structures, e.g., the cerebellum, brainstem, and eighth cranial nerve. The main symptoms of superficial siderosis are cerebellar ataxia, hearing loss, cognitive decline, and myelopathy. The activities of daily living of patients with superficial siderosis are severely impaired due to the progressive symptoms. Here, we report a patient with superficial siderosis whose symptoms deteriorated after lumbar subarachnoid-peritoneal (L-P) shunt surgery. She received L-P shunt surgery based on the diagnosis of idiopathic normal pressure hydrocephalus at another hospital. The patient had a history of cervical surgery, and a dural defect was identified at the C4-5 level by a detailed magnetic resonance imaging study. We hypothesized that the L-P shunt reduced cerebrospinal pressure and increased bleeding from the fragile vessels in the dural defect, which might have increased hemosiderin deposition.