Role of Computational Fluid Dynamics for Predicting Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage: Study Protocol for a Multicenter Prospective Study.

BACKGROUND: Delayed cerebral ischemia (DCI) is a significant cause of morbidity and mortality after aneurysmal subarachnoid hemorrhage (SAH). Recently, we reported the possibility that computational fluid dynamics (CFD) could predict DCI in terms of the cross-sectional area and flow velocity of the ipsilateral extracranial internal carotid and distal parent arteries in a single-center retrospective study. METHODS: This is a multicenter, prospective, cohort study. Patients with aneurysmal SAH will undergo CFD analyses using preoperative three-dimensional computed tomography angiography, and we will investigate hemodynamic features of cerebral arteries in an acute stage of SAH. Primary outcome measures will be CFD features in patients with subsequent occurrence of DCI. Secondary outcome measures will be CFD features in patients with subsequent occurrence of cerebral vasospasm and cerebral infarction and the relationships with eventual modified Rankin scale score at 3 months. CONCLUSIONS: The present protocol for a multicenter prospective study is expected to provide a novel diagnostic method to predict DCI before aneurysmal obliteration in an acute stage of SAH.

Tumor Embolism Through Right-to-Left Shunt Due to Venous Invasion of Esophageal Carcinoma.

A 69-year-old man was admitted to the hospital with right hemiparesis and global aphasia. Perfusion computed tomography imaging revealed ischemic penumbra in the middle cerebral artery territory. Angiography showed left middle cerebral artery occlusion. Mechanical thrombectomy with one pass was performed, and successful recanalization was obtained. Embolic material was retrieved; it contained tumor fragments with atypical keratinizing squamous cell carcinoma. Contrast computed tomography imaging indicated tumor invasion into the superior vena cava, and contrast transcranial Doppler indicated the presence of a right-to-left shunt after the Valsalva maneuver. We diagnosed the patient with acute ischemic stroke of large vessel occlusion due to venous invasion of esophageal carcinoma via a right-to-left shunt. To the best of our knowledge, this is the first case of embolic occlusion resulting from an extracardiac tumor via a right-to-left shunt. Contrast transcranial Doppler potentially detects right-to-left shunts in patients who cannot undergo transesophageal echocardiography.

Cholesterol Crystals in Embolic Debris are Associated with Postoperative Cerebral Embolism after Carotid Artery Stenting.

OBJECT: We investigated possible associations among the presence of cholesterol crystals in embolic debris, the proportions of debris components, and postoperative cerebral embolism in patients undergoing carotid artery stenting (CAS). METHODS: Sixty-seven consecutive procedures were performed for internal carotid artery stenosis with CAS at our hospital between November 2015 and February 2018. Procedures for emergency CAS for stroke in evolution or crescendo transient ischemic attack were excluded (n = 12). The embolic debris from remaining procedures (n = 55) was stained with hematoxylin-eosin and the red blood cells, white blood cells, and fibrin were quantified by color-based segmentation. Cholesterol crystals and calcification were examined histopathologically. Diffusion-weighted imaging (DWI) was performed 1-3 days after CAS, and the images were used to classify procedures according to the presence of new lesions. RESULTS: Of the 55 CAS procedures, new DWI lesions were identified after 32. One patient had symptomatic cerebral embolism. Higher proportions of patients with cholesterol crystals in embolic debris (17 vs. 78%, p < 0.001) and higher proportion of white blood cells (mean 2.3 [0-9.9] vs. 4.2% [0-29.9%], p < 0.01) were observed in the embolic debris of procedures with and without new DWI lesions. CONCLUSIONS: Cholesterol crystals were common in the embolic debris from patients with postoperative ischemic lesions after CAS. These results suggest that inflammatory destabilization of the intraplaque lipid component is related to postprocedural DWI lesions.

Multiple Cerebral Infarctions Due to Patent Foramen Ovale in a Patient with Eosinophilic Granulomatosis with Polyangiitis.

A 51-year-old man was diagnosed with eosinophilic granulomatosis with polyangiitis 6 years ago due to asthma, sinusitis, hypereosinophilia, and peripheral neuropathy based on the diagnostic criteria of American College of Rheumatology, and corticosteroid therapy achieved a remission. One year ago, he was hospitalized due to deep venous thrombosis (DVT) and pulmonary embolism, and rivaroxaban was administrated. He was admitted to our hospital for acute onset of diplopia and right hemiparesis. Peripheral blood examinations disclosed leukocytosis with hypereosinophilia. Perinuclear anti-neutrophil cytoplasmic antibodies were positive. Diffusion-weighted imaging showed multiple fresh ischemic lesions. Chronic ischemic lesions were seen in subcortical cerebral region. No stenosis or occlusion was shown in extracranial and intracranial arteries on magnetic resonance angiography. Ultrasonography of leg vein showed DVT. Right-to-left shunt through patent foramen ovale after Valsalva maneuver was seen on transesophageal echocardiography. Treatment with corticosteroid and cyclophosphamide alleviated clinical deterioration. Rivaroxaban was changed to warfarin. Diplopia and muscle strength of right limbs were improved. This is a first case of multiple cerebral infarction caused by paradoxical embolism due to patent foramen ovale with DVT based on hypercoagulable state of hypereosinophilia. Overall this case illustrates that eosinophilic granulomatosis with polyangiitis can be a risk factor for multiple cerebral infarction in the systemic phase and that transesophageal echocardiography and ultrasonography of leg vein should be conducted in stroke patient with eosinophilic granulomatosis with polyangiitis.

The Safety of Carotid Artery Stenting for Patients in the Acute Poststroke Phase.

BACKGROUND: The efficacy of carotid artery stenting (CAS) for patients in the acute poststroke phase has not been established. We investigated the outcome of CAS for patients with symptomatic internal carotid artery (ICA) stenosis in the acute poststroke phase. METHODS: We performed a retrospective analysis of all patients who underwent CAS for symptomatic ICA stenosis in our institution. Patients in whom the time interval between neurological deterioration and the CAS procedure was less than 3 days were included in the early group, and the other patients were included in the delayed group. Perioperative complications including major adverse events (MAEs) were compared between the early and the delayed groups. RESULTS: One hundred five patients were included in the study. Forty patients were assigned to the early group and 65 patients were assigned to the delayed group. The overall MAE rate was 4.8%. There was no significant increase in the perioperative MAE in the early group compared with the delayed group (early group 2.5% versus delayed group 6.5%, P = .65). In the early group, 25 of 40 patients (62.5%) were functionally independent (modified Rankin scale [mRS] score of 0-2) at discharge. Significant differences between the independent patients and the disabled patients (mRS score of 3-6) included age (independent 72 versus disabled 79, P < .01) and prevalence of transient ischemic attack (36.0% versus .0%, P = .02). CONCLUSIONS: CAS performed within 3 days from the last ischemic event did not increase the risk of perioperative complication. Early CAS may be a useful option for the treatment of symptomatic carotid artery stenosis.

Vessel Rupture Complication due to Ballooning of the Distal Segment of a JET 7 Xtra Flex Reperfusion Catheter during Angiogram.

Objective: We present a case of intraprocedural device malfunction related to the JET 7 Xtra Flex reperfusion catheter during mechanical thrombectomy. Case Presentation: A 92-year-old man presented with sudden right hemiparesis with a National Institutes of Health Stroke Scale score of 22. His left middle cerebral artery (M1) was occluded, and emergency mechanical thrombectomy was performed. After partial recanalization was achieved, angiography through a JET 7 Xtra Flex was attempted. After manual injection of contrast media via a 10-mL syringe through the JET 7 Xtra Flex, the catheter moved, jumping forward, and the distal tip of the catheter expanded and ruptured. This resulted in intracranial vessel damage and subsequent patient death. Conclusion: Contrast media must not be injected through the JET 7 Xtra Flex. If contrast media needs to be injected for angiography during mechanical thrombectomy with a reperfusion catheter, it should always be through the guide catheter.

In-hospital Ischemic Stroke Treated by Mechanical Thrombectomy.

Objective: We investigated in-hospital stroke (IHS) treated by mechanical thrombectomy in comparison with out-of-hospital stroke (OHS) to clarify the points of concern in IHS at our institution. Methods: Between September 2015 and June 2018, 19 patients with IHS who underwent mechanical thrombectomy (IHS group) were enrolled, and compared with 154 patients with OHS (OHS group) regarding patient characteristics, technical results, and outcome. In this study, we set the detection time in the IHS group as patient arrival time, termed "Door" in the OHS group. Results: Cardiology and gastroenterology were the two main admitting departments, including four (21%) patients of IHS group. In all, 15 (79%) patients had atrial fibrillation; however, less than one-third of them was taking anticoagulant drugs at onset. There were only two cases of direct consultation to the stroke specialists, although IHS onset was mainly recognized by nurses. The median age in the IHS group was 81 (interquartile range (IQR), 76-86.5) versus 80 in the OHS group (IQR, 73-85; p = 0.43), and the median initial National Institutes of Health Stroke Scale score was 21 (IQR, 16-23) versus 21 (IQR, 14-26; p = 0.92), respectively. Sex, Alberta Stroke Program Early CT Score, etiology, and occlusion site did not differ between groups. The rate of use of intravenous tissue plasminogen activator (IV-tPA) was 26% in the IHS group versus 49% in the OHS group (p = 0.065). The median time of detection to imaging, detection to needle for IV-tPA, and detection to puncture were 32, 69, and 87 minutes, respectively, in the IHS group, being significantly longer than those in the OHS group (11, 30, and 50 minutes; p <0.01, p <0.01, and p <0.01, respectively). The median time of puncture to reperfusion was 39 minutes, being significantly shorter than that in the OHS group (82 minutes; p <0.01). Successful reperfusion defined as thrombolysis in cerebral infarction (TICI) 2b-3 was obtained in 94.7% of the IHS group versus 83.1% of the OHS group (p = 0.19). A favorable outcome (modified Rankin Scale score 0-2) at 90 days was achieved by 36.8% (IHS) versus 35.1% (OHS) of patients (p = 0.88). The rate of symptomatic procedural complications was 0% (IHS) versus 7.1% (OHS; p = 0.23). The rate of death at 90 days was 15.8% (IHS) versus 12.3% (OHS; p = 0.67). Conclusion: The times of detection to imaging and of detection to puncture in the IHS group were longer than those in the OHS group; however, patients in the IHS group had shorter reperfusion. The outcome of the IHS group did not differ from that of OHS group. Our study suggests that the time course of treatment should be improved and rapid stroke pathways involved in consultation with the stroke specialists for IHS should be organized.

Erythrocyte-Rich Thrombus Is Associated with Reduced Number of Maneuvers and Procedure Time in Patients with Acute Ischemic Stroke Undergoing Mechanical Thrombectomy.

BACKGROUND: Only few studies have investigated the relationship between the histopathology of retrieved thrombi and clinical outcomes. This study aimed to evaluate thrombus composition and its association with clinical, laboratory, and neurointerventional findings in patients treated by mechanical thrombectomy due to acute large vessel occlusion. METHODS: At our institution, 79 patients were treated by mechanical thrombectomy using a stent retriever and/or aspiration catheter between August 2015 and August 2016. The retrieved thrombi were quantitatively analyzed to quantify red blood cells, white blood cells, and fibrin by area. We divided the patients into two groups - a fibrin-rich group and an erythrocyte-rich group - based on the predominant composition in the thrombus. The groups were compared for imaging, clinical, and neurointerventional data. RESULTS: The retrieved thrombi from 43 patients with acute stroke from internal carotid artery, middle cerebral artery, or basilar artery occlusion were histologically analyzed. Erythrocyte-rich thrombi were present in 18 cases, while fibrin-rich thrombi were present in 25 cases. A cardioembolic etiology was significantly more prevalent among the patients with fibrin-rich thrombi than among those with erythrocyte-rich thrombi. Attenuation of thrombus density as shown on computed tomography images was greater in patients with erythrocyte-rich thrombi than in those with fibrin-rich thrombi. All other clinical and laboratory characteristics remained the same. Patients with erythrocyte-rich thrombi had a smaller number of recanalization maneuvers, shorter procedure times, a shorter time interval between arrival and recanalization, and a higher percentage of stent retrievers in the final recanalization procedure. The occluded vessels did not differ significantly. CONCLUSIONS: In this study, erythrocyte-rich thrombus was associated with noncardioembolic etiology, higher thrombus density, and reduced procedure time.

Positional Occlusion of Vertebral Artery Due to Cervical Spondylosis as Rare Cause of Wake-up Stroke: Report of Two Cases.

BACKGROUND: Positional compression of the vertebral artery (VA) owing to cervical spondylosis is an uncommon cause of stroke. We report two cases of cervical spondylosis causing wake-up stroke, which is extremely rare. CASE DESCRIPTION: The first patient was a 78-year-old woman with vertigo and vomiting lasting from waking up. Magnetic resonance imaging (MRI) and angiography documented right cerebellar infarction, and stenosis of the right cervical VA. Dynamic angiography revealed that the right VA was occluded when her neck was extended or rotated to the right. Computed tomography (CT) angiography revealed the right VA compression by the right C5 superior articular process osteophytes. The second patient was a 77-year-old man with dysarthria from waking up. MRI and angiography revealed right cerebellar infarction associated with the right VA stenosis and the left VA occlusion at C5-C6, whose cause was diagnosed as compression caused by bilateral uncovertebral osteophytes on CT angiography. Dynamic angiography showed that neck rotation to the right aggravated the right VA stenosis while recanalizing the left VA. Both patients were treated with a free radical scavenger (edaravone) and heparin, and underwent surgical decompression of VAs 14 or 18 days after onset. No recurrent ischemic events occurred thereafter. CONCLUSIONS: Magnetic resonance angiography of extracranial cervical VAs may be useful as an initial screening test for VA compression secondary to cervical spondylosis as a rare cause of wake-up stroke, especially in cases of cerebral infarction in the posterior circulation with no evidences of causative arrhythmia and intracranial lesions.

Characteristics of Blood Blister-Like Aneurysms with a Saccular-Shape Appearance.

BACKGROUND: Blood blister-like aneurysms (BBAs) are a subgroup of aneurysms located on nonbranching sites of the internal carotid artery (ICA) and characterized by small size, a fragile wall, and a poorly defined broad-based neck. Both direct surgery and endovascular treatment for BBAs are often challenging. Some of the BBAs have been reported to look like true saccular aneurysms, and the misdiagnosis of BBA might result in catastrophic outcomes. The purpose of this study is to clarify the clinical and intraoperative findings of saccular BBAs. METHODS: We analyzed clinical and intraoperative findings in consecutive 11 patients with subarachnoid hemorrhage caused by ruptured BBA. BBAs were divided into typical BBAs, which were defined as typical tiny, broad-based, blister-like aneurysms, and saccular BBAs, which seemingly looked like true saccular aneurysms but were demonstrated to be BBAs by the intraoperative findings of the laceration of the ICA. The characteristics of saccular BBAs were analyzed. RESULTS: There were 4 patients with saccular BBAs in which the admission day was diverse from the onset day to several days after the onset. The origin of saccular BBAs was the medial (n = 2) or anterior (n = 2) walls of the ICA. Three of the 4 saccular BBAs pointed toward the optic nerve, whereas none of the typical BBAs pointed toward the optic nerve. CONCLUSIONS: Saccular BBAs may not merely develop secondarily from typical BBAs, but also form by the surrounding structures-dependent mechanisms when an aneurysm points toward the optic nerve. The findings in this study suggest that saccular-shaped aneurysms at nonbranching sites of the ICA toward the optic nerve should be considered as saccular BBAs.

Delayed Onset of Isolated Unilateral Oculomotor Nerve Palsy Caused by Post-Traumatic Pituitary Apoplexy: A Case Report.

Post-traumatic pituitary apoplexy is uncommon, most of which present with a sudden onset of severe headache and visual impairments associated with a dumbbell-shaped pituitary tumor. We experienced an unusual case of post-traumatic pituitary apoplexy with atypical clinical features. A 66-year-old man presented with mild cerebral contusion and an incidentally diagnosed intrasellar tumor after a fall accident with no loss of consciousness. The patients denied any symptoms before the accident. After 4 days, the left oculomotor nerve palsy developed and deteriorated associated with no severe headache. Repeated neuroimages suggested that pituitary apoplexy had occurred at admission and showed that the tumor compressed the left cavernous sinus. The patient underwent endonasal transsphenoidal surgery at 6 days after head injury, and the mass reduction improved the oculomotor nerve palsy completely within the following 14 days. The pathologic diagnosis was nonfunctioning pituitary adenoma with hemorrhage and necrosis.

A novel image fusion visualizes the angioarchitecture of the perforating arteries in the brain.

We report a novel technique that fuses 3D digital subtraction angiograms and MR images. Image fusion was successfully performed within 20 minutes each in 11 consecutive cases. Our initial experience showed that this image fusion enabled clear and simultaneous visualization of perforating arteries and surrounding tissues. The relation between perforating arteries and normal brain or lesions was easily understood in a clinical setting by using this image fusion.