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Background: Design of flow-diverter stents for flexibility, tractability, and low profile limits their radiopacity on conventional digital subtraction angiography. Cone-beam computed tomography (CBCT) offers higher spatial resolution for the evaluation of flow-diverter stents. However, CBCT requires optimal dilution and timing of contrast medium for simultaneous visualization of the stent, arterial lumen, and vessel wall. There are only limited data on the effects of different contrast dilutions on CBCT image quality in neurointerventional applications., Materials and Methods: In our institution, intra-arterial CBCTs were acquired during stent deployment and at follow-ups with 10% diluted contrast. We had recently started acquiring intra-arterial CBCTs with non-diluted contrast. Retrospective analysis of our flow-diverter data identified eight cases with different aneurysm locations who had intra-arterial CBCT with 10% diluted contrast immediately after flow-diverter stent deployment and with non-diluted contrast technique during follow-ups. For each case, the image quality between diluted and non-diluted contrast techniques was compared qualitatively by assessing stent visualization and quantitatively by plotting gray-scale intensity values along the vessel lumen., Results: In two sets of CBCT images per each case, there was no substantial difference between diluted and non-diluted CBTC techniques for the evaluation of stent architecture and lumen opacification. Gray-scale intensity values perpendicular to the lumen revealed similar intensity values along the neighboring parenchyma, vessel wall, and lumen for the two different contrast techniques., Conclusion: Intra-arterial CBCT angiography can be performed without contrast dilution and still achieve adequate image quality in certain cerebral aneurysms treated with flow diverter. The non-diluted contrast technique avoids the time loss during preparation of diluted contrast and installation of diluted contrast to the injector in angiography suites with a single power injector.

Background: The LVIS Jr device holds a number of advantages but poses unique technical challenges compared to such, especially, complex multistent constructs. We report our experience with the technical feasibility and early to mid-term outcomes of Y-stent-assisted coiling with the LVIS Jr using a simple, single microcatheter technique., Methods: Using a departmental database, we retrospectively reviewed a single surgeon's experience with Y-stent-assisted coiling with LVIS Jr over a three-year period. Eighteen aneurysms in 17 patients were treated over this period. We assessed the technical success of the procedures, the initial and follow-up radiographic success with the modified Raymond-Roy occlusion score and follow-up clinical outcome with the modified Rankin scale., Results: All stents were successfully deployed, and 17 of 18 aneurysms were successfully coiled at the initial treatment for a technical success rate of 94.4%. Of the 17 aneurysms with follow-up imaging, all were modified Raymond-Roy grade 1 or 2. One aneurysm required retreatment for coil compaction and a growing neck. There were two immediate postprocedure symptomatic strokes and one delayed stroke related to antiplatelet non-compliance. The two immediate symptomatic strokes recovered to neurological baseline with no residual deficits by the time of discharge. The long-term morbidity rate was 5.5%. The mortality rate was 0%. All patients had a modified Rankin Scale ≤ 2 at most recent follow-up., Conclusion: Treatment with LVIS Jr Y-stent constructs via a single microcatheter technique is technically feasible with good radiographic and clinical outcomes.

Objective: To review the microsurgical anatomy of the donor arteries for extracranial-intracranial bypass, namely, the superficial temporal artery (STA), occipital artery (OA), and internal maxillary artery (IMA)., Methods: Seven cadaveric specimens were dissected to identify the relationships between each artery and its surrounding structures. Nineteen computed tomographic angiographic images of Japanese adult patients (38 sides) were analyzed to examine the course of each artery and to measure the diameters and distances from various anatomic landmarks to each artery., Results: The courses of the STA, OA, and IMA, which must be exposed during revascularization procedures, were shown via cadaver dissection with special reference to the following relationships to surrounding structures: STA, soft tissue layers of the temporoparietal region and facial nerve; OA, suboccipital muscles; and IMA, mandibular nerve. In addition, we measured the diameter of the anastomotic site for each artery and its relationship with surrounding muscles., Conclusions: A precise understanding of the anatomic characteristics of the donor arteries and their relationships with surrounding structures provides safe access to these arteries., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Purpose: To investigate the long-term outcome of stent angioplasty for symptomatic severe intracranial artery stenosis., Method: In this study 95 consecutive patients with intracranial atherosclerotic stenosis (>70%) underwent stent angioplasty using Wingspan stents. The primary endpoints were stroke or death within 30 days of the procedure and subsequent stroke attributed to the stented vessel. Disabling stroke was defined as stroke with a modified Rankin scale > 3. Secondary endpoints included transient ischemic attacks, contralateral stroke, nonstroke death, and other events. Patients underwent prestent balloon dilation with or without poststent balloon dilation, close restenosis follow-up, and selective retreatment, as required., Result: The mean follow-up duration was 34.9 ± 23.3 months. Primary endpoint events occurred in 23% of the patients. The median infarction volume was 2.6 ml, and 11 (68%) of 16 infarctions were <5 ml in volume. Disabling stroke occurred in 3% of patients. The primary endpoint rates were 17.9% within 30 days and 2.1% from 30 days to 1 year. Secondary endpoint events occurred in 27.3% of the patients. Mean stenosis was reduced from 76.8 ± 6.1% to 7.5 ± 13.4%. Of 80 patients who underwent angiographic follow-up, 11 (14%) experienced restenosis (≥50%) and 7 (9%) exhibited restenosis-related symptoms of transient ischemic attack. The rate of symptomatic restenosis was significantly higher in patients who underwent prestent balloon dilation alone than in patients who underwent prestent and poststent balloon dilation (p = 0.016)., Conclusion: The postprocedural stroke rate was similar to that observed in the SAMMPRIS study. Symptomatic restenosis may be reduced by poststent dilation, close angiographic follow-up, and retreatment.

Introduction: Persistent trigeminal artery (PTA) is the most common remnant of primitive circulation communicating the developing carotid and vertebrobasilar junction. Although discovered incidentally, an altered hemodynamic may lead to an increased association of aneurysms, vascular malformations, and stroke. Neurosurgeons should be aware of the presence and significance of PTA when interpreting imaging and planning interventions., Methods: We retrospectively reviewed all magnetic resonance angiography and cerebral digital subtraction angiography performed between 2012 and 2017 for the presence of PTA. The radiologic and anatomic details were noted and analyzed along with the clinical profiles. We categorized the radiologic findings with respect to the available classification systems. A review of the available literature was done comparing our results., Results: We found 33 cases of incidentally detected PTA. The average age of the patients was 45.42 years. The lateral surface of the proximal cavernous internal carotid artery was the most common origin (n = 23). Only 3 cases had a medial/transsellar course. Most cases were Saltzman/Weon type I (19/33). Intracranial aneurysms were associated with 6 patients (18.18%). Trigeminal neuralgia (TN) was a presenting feature in 5 patients. None had a direct neurovascular conflict at the root entry zone., Conclusions: Our study is one of the largest to describe the incidence of PTA. We emphasized the importance of PTA to the neurosurgeons; increased association of aneurysms, as a route for intervention in occlusive disease of the posterior fossa; risk of injury and bleeding during transsphenoidal surgery; and the association with TN. However, we found that only PTA variants are likely to be associated with TN because of their cisternal course causing NV conflict., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: The transradial approach as a frontline approach is a novel technique in neuroendovascular procedures. In this study we aim to present our early experience with full transition to transradial access as the first-line approach for neuroendovascular procedures., Methods: We prospectively collected data on the first 100 consecutive patients who underwent a diagnostic or interventional neuroendovascular procedure using the transradial approach at our institution between March 22 and April 30, 2019. Baseline characteristics were collected in addition to the type of procedure, access site, catheters and wires used, complications, and whether there was crossover to transfemoral access., Results: Transradial access was attempted in 121 cases and 91 cases were completed successfully (72 diagnostic procedures and 19 interventional procedures). Mean (SD) age was 56.8 (14.7) years, 54.9% (50/91) underwent the procedure in the outpatient setting, and 60.4% (55/91) were women. Seven patients had minor immediate complications related to the radial access. Interventional procedures successfully performed included aneurysm embolization (ruptured (n=3) and unruptured (n=8)), tumor embolization (n=2), cervical internal carotid artery stenting (n=2), balloon occlusion test (n=1), vertebral artery sacrifice (n=1), and arteriovenous malformation embolization (n=2)., Conclusion: In this early experience, full transition to the transradial approach as the frontline approach is feasible with a low complication rate for both diagnostic and interventional neuroendovascular procedures., Competing Interests: Competing interests: AS: Penumbra consulting, Minnetronix consulting, Cerenovus consulting., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Introduction: Surgical treatment of cerebral ischemia at the Burdenko Neurosurgical Center for the period from 1999 to 2019 is analyzed in the paper. The details of the treatment strategy in patients with steno-occlusive lesion of craniocervical arteries followed by cerebral ischemia developed over 20 years are discussed in the article. We have analyzed the features of surgical interventions on the major craniocervical arteries in a neurosurgical clinic and the results of this treatment., Objective: To demonstrate management of various lesions of major cerebral arteries in modern neurosurgical vascular hospital., Material and Methods: In total, there were 3098 interventions on the major cerebral arteries in 2527 patients for this period. Mean age of patients ranged from 1.5 to 91 years (58±14 years). Interventions included open reconstructions of the carotid arteries (2031 surgeries), reconstructions of the vertebrobasilar arteries (135 surgeries), brain revascularization (658 surgeries), excision of the tumors of neurovascular bundle on the neck compressing carotid arteries (51 interventions). Endovascular interventions were performed in 223 cases and consisted of angioplasty and stenting of the extracranial segments of craniocervical arteries (185 surgeries), stenting of the intracranial arteries (30 surgeries) and endovascular thrombextraction (8 cases). Staged surgeries were performed in 541 patients (22.3%)., Results: Favorable outcomes were obtained in 87.6% of cases, satisfactory results - in 9% of patients. Clinical deterioration due to long-term postoperative complications and recurrent strokes occurred in 2.9% of cases. Postoperative morbidity rate was 4.6%, persistent neurological deficit developed in 2.6% of cases. Mortality rate was 0.5%., Conclusion: Surgical treatment of stenotic and occlusive lesion of the major cerebral arteries is an interdisciplinary problem. Solution of this issue is closely associated with technological progress, new discoveries in normal and pathological physiology, as well as clinical researches. Individualized choice of surgical approach is one the main modern trends of neurosurgical approach to this problem. At the same time, own surgical experience is the most important factor determining the results of arterial reconstructions.

Previous studies have shown that metformin not only is a hypoglycemic agent but also has neuroprotective effects. However, the mechanism of action of metformin in ischemic stroke is unclear. Oxidative stress is an important factor in the pathogenesis of cerebral ischemia-reperfusion injury. It has been reported that metformin is associated with stroke risk in the clinical population. This study is aimed at investigating the effect and mechanism of metformin in an experimental model of oxidative stress induced by ischemia/reperfusion (I/R) in vivo and oxygen glucose deprivation/reperfusion (OGD/R) in vitro . Metformin (100, 200, and 300 mg/kg) was administered intraperitoneally immediately after induction of cerebral ischemia. The indicators of oxidative stress selected were antioxidant enzyme activities of catalase, malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), and glutathione peroxidation enzyme (GSHPx). First, we demonstrated that metformin can significantly alleviate acute and chronic cerebral I/R injury and it has a strong regulatory effect on stroke-induced oxidative stress. It can reduce the elevated activities of MDA and NO and increase the levels of GSHPx and SOD in the cerebrum of mice and N2a cells exposed to I/R. Furthermore, real-time PCR and western blot were used to detect the expression of long noncoding RNA H19 (lncRNA-H19), microRNA-148a-3p (miR-148a-3p), and Rho-associated protein kinase 2 (Rock2). The direct interaction of lncRNA-H19, miR-148a-3p, and Rock2 was tested using a dual luciferase reporter assay. lncRNA-H19 altered OGD/R-induced oxidative stress by modulating miR-148a-3p to increase Rock2 expression. The expression of lncRNA-H19 and Rock2 could be downregulated with metformin in vivo and in vitro . In conclusion, our study confirmed that metformin exerts neuroprotective effects by regulating ischemic stroke-induced oxidative stress injury via the lncRNA-H19/miR-148a-3p/Rock2 axis. These results provide new evidence that metformin may represent a potential treatment for stroke-related brain injury., Competing Interests: The authors declare that they have no competing interests., (Copyright © 2019 Jing Zeng et al.)

Although direct bypass is effective at preventing intracranial hemorrhage in moyamoya disease, the optimal strategy for achieving this purpose has rarely been addressed. The tailored targeting bypass strategy is a novel technical modification of direct bypass focused on hemorrhage prevention. The strategy is based on the promising theory of periventricular anastomosis, which explains the mechanism of hemorrhage in moyamoya disease. The strategy is defined as the use of multi-imaging modalities to predetermine in a tailored manner a target vessel at the point at which the medullary artery directly extends from the periventricular anastomosis of interest. Direct bypass with a wide craniotomy was performed on 13 hemispheres in eight patients according to this strategy. Marked shrinkage of the periventricular anastomosis of interest was observed in all but one hemisphere after surgery, and no new hemorrhages have occurred as of this writing. The present case series illustrates the technical aspects and preliminary results of the tailored targeting bypass strategy, an approach that might expand the potential of direct bypass in preventing hemorrhage.

Objectives: The optimal treatment of symptomatic non-acute atherosclerotic intracranial large artery occlusion (ILAO) beyond 24 h from onset remains uncertain. We investigate the outcomes of late endovascular recanalization for symptomatic non-acute atherosclerotic ILAO., Patients and Methods: From September 2013 to July 2018, with safety as the first principle, late endovascular recanalization for symptomatic non-acute atherosclerotic ILAO beyond 24 h from onset was attempted in 32 consecutive patients. Primary safety outcome was any stroke or death within 30 days. Primary efficacy outcome were functional independence at 90 days., Results: The median time from imaging-documented occlusion to treatment was 25.5 days (interquartile range: 10.5-36.5) for all patients. Technical success in recanalization was achieved in 17 patients (53.1%, 17/32). The 30-day rate of any stroke or death was 5.9% (1/17) in the recanalized group versus 6.7% (1/15) in the failure group (P = 0.927). The rate of functional independence at 90 days (70.5%, 12/17) was increased significantly as compared with that before operation (23.5%, 4/17) in the recanalized group (P = 0.015). The rate of functional independence at 90 days (66.7%, 10/15) was not different from that before operation (66.7%,10/15) in the failure group (P = 1.00). The median score reduction in mRS from baseline at 90 days was 1.0 (interquartile range: 1.0-2.0) in the recanalized group versus 0 (interquartile range: 0.0-0.0) in the failure group (P＜0.001)., Conclusion: For carefully selected patients with symptomatic non-acute atherosclerotic ILAO beyond 24 h from onset, late endovascular recanalization is technically feasible. The periprocedural safety of late endovascular recanalization is acceptable. Successful recanalization may effectively improve the degree of disability in such patients. However, it should be emphasized that revascularization of non-acute ILAO is a high risk procedure, which should only be performed by experienced operators with safety as the first principle., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Many neuroendovascular treatments are supported by real-time anatomical and visual hemodynamic assessments through digital subtraction angiography (DSA). Here we used DSA in a single-center prospective randomized crossover study to assess the intracranial hemodynamics of patients undergoing coiling for cerebral aneurysm (n = 15) during sevoflurane- and propofol-based anesthesia. Color-coded DSA was used to define time to peak density of contrast medium (TTP) at several intravascular regions of interest (ROIs). Travel time at a particular ROI was defined as the TTP at the selected ROI minus TTP at baseline position on the internal carotid artery (ICA). Travel time at the jugular bulb on the anterior-posterior view was defined as the cerebral circulation time (CCT), which was divided into four segmental circulation times: ICA, middle cerebral artery (MCA), microvessel, and sinus. When bispectral index values were kept between 40 and 60, CCT (median [interquartile range]) was 10.91 (9.65-11.98) s under propofol-based anesthesia compared with 8.78 (8.32-9.45) s under sevoflurane-based anesthesia (P < 0.001). Circulation times for the ICA, MCA, and microvessel segments were longer under propofol-based anesthesia than under sevoflurane-based anesthesia (P < 0.05 for all). Our results suggest that, relative to sevoflurane, propofol decreases overall cerebral perfusion.

Background: Recurrent trigeminal neuralgia after successful microvascular decompression is not rare., Case Description: A 72-year-old woman who presented with typical right trigeminal neuralgia had been successfully treated by microvascular decompression with transposition of the superior cerebellar artery. However, she complained of trigeminal neuralgia on the ipsilateral side 14 months after the microvascular decompression. Redo microvascular decompression showed that the anterior inferior cerebellar artery, which had not been detected at the initial surgery, compressed the right trigeminal nerve., Conclusions: This case is an unusual type of recurrent trigeminal neuralgia because of a subsequently developed offending vessel within a short period., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Hemifacial spasm is a cranial nerve compression syndrome caused by impingement on the facial nerve most frequently by the anterior inferior cerebellar artery or the posterior inferior cerebellar artery. It can be treated with microvascular decompression (MVD) to separate the nerve from the offending artery. Rarely, a large-caliber vessel such as a dolichoectatic vertebrobasilar system may be implicated, requiring more than an MVD. One technique involves placing a sling around the offending vessel to decompress the facial nerve. We find our "neck-tie" technique to be unique and present it in this detailed video. A 36-year-old-woman presented with a 3-month history of severe left hemifacial spasm refractory to medical management. Imaging demonstrated compression of the left facial nerve and its root entry zone by a dolichoectatic vertebrobasilar complex and anterior inferior cerebellar artery. A left retrosigmoid craniotomy was performed. A Dacron sling was placed around the offending vertebral artery in a "neck-tie" fashion. This sling was used to displace the vertebral artery off of the facial nerve and the sling was then sutured in its final position to the petrous dura. In addition, MVD was performed around the facial nerve's root entry zone. Following sling placement and MVD, neuromonitoring demonstrated absence of abnormal motor responses. Postoperative course was uneventful, she remained neurologically intact, and she remained free of symptoms at 6 months' follow-up. This video highlights the decision making for selecting the appropriate case of hemifacial spasm for sling decompression, the key technical nuances, and complication avoidance in these challenging cases., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Microparticles (MPs, ~size between 0.1 and 1 mm) are lipid encased containers derived from intact cells which contain antigen from the parent cells. MPs are involved in intercellular communication and regulate inflammation. Stroke increases secretion of brain derived MP (BDMP) which activate macrophages/microglia and induce neuroinflammation. Lactadherin (Milk fat globule-EGF factor-8) binds to anionic phospholipids and extracellular matrices, promotes apoptotic cell clearance and limits pathogenic antigen cross presentation. In this study, we investigate whether BDMP affects stroke-induced neuroinflammation and whether Lactadherin treatment reduces stroke initiated BDMP-induced neuroinflammation, thereby improving functional outcome after stroke. Middle aged (8-9 months old) male C57BL/6J mice were subjected to distal middle cerebral artery occlusion (dMCAo) stroke, and BDMPs were extracted from ischemic brain 24 h after dMCAo by ultracentrifugation. Adult male C57BL/6J mice were subjected to dMCAo and treated via tail vein injection at 3 h after stroke with: (A) +PBS ( n = 5/group); (B) +BDMPs (1.5 × 10 8 , n = 6/group); (C) +Lactadherin (400 μg/kg, n = 5/group); (D) + BDMP +Lactadherin ( n = 6/group). A battery of neurological function tests were performed and mice sacrificed for immunostaining at 14 days after stroke. Blood plasma was used for Western blot assay. Our data indicate: (1) treatment of Stroke with BDMP significantly increases lesion volume, neurological deficits, blood brain barrier (BBB) leakage, microglial activation, inflammatory cell infiltration (CD45, microglia/macrophages, and neutrophils) into brain, inflammatory factor (TNFα, IL6, and IL1β) expression in brain, increases axon/white matter (WM) damage identified by decreased axon and myelin density, and increases inflammatory factor expression in the plasma when compared to PBS treated stroke mice; (2) when compared to PBS and BDMP treated stroke mice, Lactadherin and BDMP+Lactadherin treatment significantly improves neurological outcome, and decreases lesion volume, BBB leakage, axon/WM injury, inflammatory cell infiltration and inflammatory factor expression in the ischemic brain, respectively. Lactadherin treatment significantly increases anti-inflammatory factor (IL10) expression in ischemic brain and decreases IL1β expression in plasma compared to PBS and BDMP treated stroke mice, respectively. BDMP increases neuroinflammation and aggravates ischemic brain damage after stroke. Thus, Lactadherin exerts anti-inflammatory effects and improves the clearance of MPs to reduce stroke and BDMP induced neurological deficits., (Copyright © 2019 Chen, Chopp, Zacharek, Li, Venkat, Wang, Landschoot-Ward and Chen.)

Background: Ruptured wide-neck aneurysms (WNAs) are difficult to treat and few publications have compared clipping to coiling., Objective: To determine, using Barrow Ruptured Aneurysm Trial (BRAT) data: (1) How many aneurysms had a wide neck? (2) Did wide-neck status influence treatment? (3) How did clipping compare to coiling for WNAs?, Methods: A post hoc analysis was conducted of saccular WNAs in the BRAT. A WNA was defined as maximum neck width ≥ 4 mm or maximum aneurysm dome-diameter-to-neck-width ratio < 2. Both intent-to-treat and as-treated analyses were performed., Results: Of the 327 patients analyzed, 177 (54.1%) had a WNA. WNAs were more likely to occur in older patients (P = .03) with worse presenting clinical grade (P = .02), were more likely to arise from the middle cerebral artery, basilar tip, or internal carotid artery other than the junction with the posterior communicating artery (P = .001) and were associated with worse clinical outcomes at all time points (P ≤ .01). WNAs were equally distributed in assigned treatment groups (clip 56.6% vs coil 51.8%; P = .38), but were overrepresented in the actual clipping group (clip 62.4% vs coil 37.6%, P < .001). Most patients (76.7%) in the coil-to-clip crossover group had a WNA. Comparing clipping to coiling, there was no difference in clinical outcomes at any time point in either analysis (P ≥ .33). The aneurysm obliteration rate was lower (P < .001) and the retreatment rate higher (P < .001) in the actual coiling group., Conclusion: Wide-neck status significantly impacted treatment strategy in the BRAT, favoring clipping. Clipping and coiling of ruptured WNAs resulted in statistically similar long-term clinical outcomes. 10.1093/neuros/nyy439 Video Abstract 10.1093.neuros.nyy439 5850292551001., (Copyright © 2018 by the Congress of Neurological Surgeons.)

Objectives: To identify predictors of atherosclerotic change in aneurysms and parent arteries, and to retrospectively analyze outcomes from clipped aneurysms that showed atherosclerotic changes., Methods: Between May 2017 and April 2018, we collected a total of 151 clipping cases and reviewed records of operation videos to classify atherosclerosis by location (dome, neck of aneurysm, or parent artery). To identify predictors of atherosclerotic change in aneurysms, we analyzed baseline demographic characteristics, preoperative images, and Framingham Risk Scores (FRS). We also analyzed incomplete clipping cases according to atherosclerosis presence and location., Result: This study cohort included 110 women (mean age, 59.3 ± 7.1 years) and 41 men (mean age, 55.9 ± 9.6 years). Atherosclerotic change was seen in 77 cases. FRS, diabetes mellitus, and aneurysm size were identified as independent risk factors for atherosclerotic change in multivariate logistic regression analysis. There were 11 incomplete clipping cases (7.2%). Among the 30 cases with atherosclerotic change in the neck were 10 cases of incomplete clipping (P < 0.001)., Conclusions: FRS, diabetes mellitus, and aneurysm size as predictors of atherosclerosis in patients undergoing aneurysm surgery can help guide surgical decisions and performance., (Copyright © 2019. Published by Elsevier Inc.)

Background: Some mechanical thrombectomy techniques for acute ischemic stroke use a combination of an aspiration catheter and stent retriever. We experienced a rare case of aspiration catheter coil breakage and subsequent retrieval using a stent retriever., Case Description: A 79-year-old man suddenly developed somnolence, global aphasia, and right hemiplegia. Magnetic resonance imaging revealed acute infarction of the left frontal lobe and occlusion of the left common carotid artery. Thus, using an aspiration catheter and a stent retriever, mechanical thrombectomy was performed. The stent retriever was deployed from the middle cerebral artery to the internal carotid artery and retracted into the aspiration catheter placed in the internal carotid artery proximal to the thrombus. The catheter was bent during retraction of the stent retriever. After thrombus aspiration, the internal carotid and anterior and middle cerebral arteries were successfully reperfused; however, the stent retriever captured a broken section of the winding coil of the aspiration catheter. We suspected that an X-ray marker on the stent retriever broke the winding coil at the bent segment of the aspiration catheter and the stent captured the broken coil., Conclusions: The combined use of an aspiration catheter and a stent retriever may cause unexpected device breakage, especially when the catheter is bent., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Introduction: Pivotal trials have shown the tremendous efficacy of mechanical thrombectomy in proximal occlusions. However distal occlusions involving second-order branches of the middle cerebral artery and beyond, anterior cerebral and posterior cerebral arteries were not represented. In this study, we investigated the feasibility and safety of distal circulation mechanical thrombectomy., Methods: A retrospective review of patients presenting with distal circulation acute ischemic stroke who underwent mechanical thrombectomy 2010 and 2018., Results: Of 453 patients who underwent mechanical thrombectomy for acute ischemic stroke, 76 had a distal occlusion. The mean National Institute Health Stroke Scale on admission was 12. Vessels involved included second-order branches of the middle cerebral artery (89%), third- and fourth-order branches of the middle cerebral artery (5%), second-order branch of the anterior cerebral artery (3%), and posterior cerebral artery (3%). Most procedures required 1 pass to recanalize the vessel (55%, n = 42). Thrombolysis in Cerebral Infarction score ≥IIb was achieved in 89% of subjects. Mortality rate was 8% and independent functional outcome of m Rankin score ≤2 at 3 months was seen in 64.7% with clinical follow-up. On multivariate analysis, distal circulation had a significantly shorter length of stay by about 2 days, compared with proximal circulation. Subjects with proximal occlusion were more than 5 times more likely to have a good Thrombolysis in Cerebral Infarction score compared with the distal group. There was no significant difference in periprocedural and postprocedural complications, good functional outcome at 3 months, and mortality between both groups., Conclusions: Mechanical thrombectomy procedure for distal circulation strokes is as effective and safe as a proximal group. Though distal vessels supply smaller brain area; however, when symptoms are pronounced, the benefit of the procedure outweighs the risks., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Acute anterior inferior cerebellar artery (AICA) occlusion is considered an acute ischemic stroke requiring medical treatment without mechanical thrombectomy (MT). There is a procedural risk of parent vessel rupture, but neurologic deficits are not generally severe. Here, we report a case of MT performed using partially deployed stent retrieval for acute AICA occlusion., Case Description: A 53-year-old male patient presented with acute-onset drowsiness and visual disturbance. The initial National Institutes of Health Stroke Scale score of the patient was 5. Computed tomography angiography showed no definite vascular occlusion, but computed tomography perfusion imaging suggested decreased cerebral blood flow and cerebral blood volume, with an increased mean transit time and time to peak in the left posterior inferior cerebellar artery territory. Conventional angiography showed occlusion of the left proximal AICA and posterior inferior cerebellar artery cortical branches, which were reconstituted by the muscular branches of the left vertebral artery. We decided to perform intra-arterial thrombectomy for proximal left AICA occlusion because the patient's symptoms seemed to be aggravated, and neurologic deficits were not expected. MT was performed using a Trevo stent (Stryker Neurovascular, Fremont, California, USA) in the left proximal AICA via a right vertebral artery approach and resulted in complete recanalization of the occluded AICA. The patient recovered and had an National Institutes of Health Stroke Scale score of 0 at 1 day after MT., Conclusions: Our case suggests that MT can be performed in a highly selective manner in patients with the occlusion of a posterior circulation branch, such as the AICA, and yield a good clinical outcome., (Copyright © 2019 Elsevier Inc. All rights reserved.)

BACKGROUND Lung cancer with intracranial metastasis requires concurrent treatment of the primary lung tumor and the secondary brain tumor. This study aimed to investigate the short-term clinical efficacy of concurrent bronchial artery and posterior inferior cerebellar artery microcatheter interventional chemotherapy for the treatment of adenocarcinoma of the lung with solitary cerebellar metastasis. MATERIAL AND METHODS Seventeen patients with adenocarcinoma of the lung with solitary cerebellar metastasis received concurrent microcatheter interventional chemotherapy via the bronchial artery and posterior inferior cerebellar artery. Two cycles of treatment with teniposide (VM-26), carmustine (BCNU), carboplatin (CBP), and pirarubicin (THP) were performed every four weeks. RESULTS Four patients (23.53%) achieved a complete response (CR), five patients (29.41%) achieved a partial response (PR), seven patients (41.18%) had stable disease (SD), and only one patient (5.88%) developed progressive disease (PD). The objective response rate (ORR) and disease control rate (DCR) were 52.94% (9/17) and 94.12% (16/17), respectively. Four patients (11.76%) developed grade 1/2 chemotherapy toxicity, which included three cases (8.82%) of gastrointestinal toxicity and one case (2.84%) of granulocytopenia, but no grade 3/4 toxicity was found. During microcatheter interventional chemotherapy, three patients (8.82%) developed intracranial complications, including two cases (5.88%) of cerebrovascular spasm and one case (2.94%) of cerebral edema. CONCLUSIONS In 17 patients with adenocarcinoma of the lung with solitary cerebellar metastasis, concurrent microcatheter interventional chemotherapy via the bronchial artery and posterior inferior cerebellar artery was safe and showed short-term efficacy.

Background: Persistent primitive trigeminal artery (PPTA) is the most common type of fetal carotid-basilar persisting communication in adulthood; however, carotid-cavernous fistulas (CCFs) associated with PPTA are rare., Case Description: An 84-year-old woman presented with traumatic CCF associated with PPTA manifesting as vascular bruit. Transarterial embolization was performed. Although a detachable coil was deployed at the fistula point, it was easy to migrate into the cavernous sinus because of the high-flow shunt. Therefore, a stent was deployed in the PPTA, and the inner lumen of the stent with a focus on the fistula point was occluded by using coils. Subsequently, the CCF completely disappeared., Conclusions: In-stent coil embolization was effective and reasonable for the high-flow CCF associated with the PPTA. This method reduced the number of coils required and operating time. However, careful preservation of perforators is needed., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Severe carotid and intracranial artery stenosis disease (CIAD) is major risk for perioperative stroke in coronary artery bypass grafting. Then, preoperative risk assessment is quite important., Case Presentation: A 58-years old Japanese woman with bilateral carotid stenosis and bilateral middle cerebral artery occlusion was suffered from worsening effort angina due to severe three coronary vessel disease. Magnetic resonance imaging angiography demonstrated severe carotid and intracranial vessel stenosis. Selective carotid/cerebral angiography also showed severe stenosis and delayed filling of the right internal carotid artery and moderate stenosis of the left internal carotid artery, with occlusion of the bilateral middle cerebral arteries. However, quantitative evaluation with brain perfusion, single-photon emission computed tomography (SPECT) with acetazolamide showed depleted cerebral perfusion volume and vascular responses, particularly in the left middle cerebral artery area. However, both sides of MCA reserve cerebral blood flow was maintained at > 34 ml/100 g/min. So, we finally considered that her cerebral perfusion reserve was maintained a certain level and could tolerate open heart surgery. Then, she underwent off-pump coronary artery grafting. Before sternotomy, prophylactic intra-aortic balloon pump support was used to minimize possible perioperative stroke. As a result, hemodynamic status and brain regional oxygen saturation were stable throughout the operation, and recovered uneventfully., Conclusions: Preoperative quantitative evaluation using brain perfusion SPECT with acetazolamide is useful in assessing hemodynamic cerebrovascular risk in patients with severe obstructive CIAD. Off pump coronary artery bypass grafting with intra aortic balloon pump assist is a good option for prevention of cerebrovascular morbidity in ischemic heart disease with severe CIAD.

Objective: To report efficacy and outcome of mechanical thrombectomy for treatment of pediatric acute ischemic stroke with large vessel occlusion using stent retrievers., Methods: Retrospective record review of institutional database for patients <18 years of age., Results: Five boys aged between 6 to 17 years received reperfusion therapy using mechanical thrombectomy for acute ischemic stroke with large vessel occlusion (2 basilar, 2 middle cerebral and 1 internal carotid artery). Pediatric National Institute of Health Stroke Scale (PedNIHSS) at onset ranged from 12 to 21. Complete recanalization as defined by the modified Treatment In Cerebral Infarction scale (mTICI 3 or 2b) was achieved in all, using stent retreivers. Favorable outcome as per the modified Rankin scale (mRS 0-1) was achieved in all with no peri-procedural complications., Conclusion: Mechanical thrombectomy using retrievable stents is a safe and effective therapy for pediatric ischemic stroke due to large vessel occlusion, and may be offered in carefully selected patients.

Objective: Very small intracranial aneurysms (VSIAs) are challenging to treat because aneurysm tearing and clip slippage can occur during neurosurgical clipping. In this study, we introduce and share our experience with cotton-assisted clipping of VSIAs., Methods: We retrospectively analyzed the data of 20 patients with 24 VSIAs treated with cotton-assisted clipping between February 2008 and December 2014 in the Neurosurgery Departments of the First Affiliated Hospital, Soochow University and Taizhou People's Hospital. During surgery, 2 aneurysm necks were torn. To treat the tears, we wrapped rectangular cotton pads around the parental arteries at the site of rupture. The remaining 22 aneurysms were clipped after being wrapped in cotton pads., Results: The 2 aneurysm ruptures were successfully repaired with cotton-assisted clipping. In the remaining 22 aneurysms, no cases of aneurysm clip slippage or aneurysm rupture occurred. Patients were followed up on average for 59.0 months (range, 30-113 months). Of the 20 patients, the 16 patients with preoperative Hunt-Hess grades of 1-3 recovered well after the surgery (Glasgow Outcome Scale [GOS] score, 5). Of the 4 patients with Hunt-Hess grades of 4-5, 3 had a good recovery (GOS scores, 4-5), and 1 patient died of heart disease 6 months after being discharged from the hospital; this patient had a GOS score of 4 at the time of discharge., Conclusions: Cotton-assisted clipping could prevent aneurysm clip slipping and aneurysm rupture and facilitate the repair of aneurysm neck tears. This technique is a useful alternative therapy for VSIAs., (Copyright © 2019. Published by Elsevier Inc.)

Purpose: This study aimed to report the clinical findings and initial clinical experience of endovascular recanalization for symptomatic subacute/chronic intracranial large artery occlusion (ILAO) of the anterior circulation., Methods: From October 2015 to December 2017, 13 patients with symptomatic subacute/chronic ILAO of the anterior circulation were enrolled in this study and underwent endovascular recanalization. We collected the initial procedural results, including the rate of successful recanalization and periprocedural complications, and data pertaining to angiographic and clinical follow-up., Results: Recanalization was successful in 11 of 13 patients (84.6%). Intraoperative complications occurred in four cases, including symptomatic distal embolism in three cases; one of which was simultaneously complicated with artery dissection. Intracerebral hemorrhage occurred in one case. Eleven patients underwent angiographic follow-up, and 12 patients underwent clinical follow-up. The results of the angiography follow-up (mean 6 ± 3.29 months) showed that in-stent restenosis occurred in one of the 11 successfully recanalized patients. However, the artery was occluded again in the patient who achieved thrombolysis in cerebral infarction (TICI) grade of 2a after treatment. Clinical follow-up (mean 5.8 ± 2.25 months) showed no recurrence of transient ischemic attack (TIA) or stroke in ten successfully recanalized cases. However, the patient who developed in-stent stenosis suffered TIA., Conclusions: Endovascular recanalization for symptomatic subacute/chronic ILAO of anterior circulation is feasible, relatively safe, and efficacious in highly selected cases, improving patients' symptoms in the short-term. However, further larger scale pilot studies are needed to determine the efficacy and long-term outcome associated with this treatment.

Objective: To summarize the characteristics of and therapeutic options for cancer patients whose treatments may be vasotoxic and cause intracranial arterial stenotic disease and stroke., Methods: We describe 3 patients with symptomatic cerebrovascular pathology that were being actively treated for cancer., Results: Two of the patients were being treated with tyrosine kinase inhibitors (TKIs); and the third was being treated with 2 monoclonal antibodies, one of which was targeting an endothelial growth factor. These agents have been associated with vascular adverse events. Surgical revascularization was done in the first 2 patients, as they were suffering from cerebral ischemia. The third patient had suffered a significant brain hemorrhage, and therapeutic options were limited. In the first 2 patients, treatments also included antiplatelet agents and stopping/changing the TKI. In one of these patients we demonstrated regression of arterial stenosis after changing the TKI., Conclusions: Possibilities for treatment in this population, beyond the usual medical and surgical administrations, may include stopping or changing cancer drugs that may be related to the development of arterial pathology. Collaboration with oncologists is essential in this subset of patients. While aware of the potential for vascular toxicity, oncologists are often not fully appreciative of the fact that their therapeutic agents can cause stroke., (Copyright © 2019. Published by Elsevier Inc.)

Background: Suprachiasmatic subcallosal lesions may have an intimate relationship with the anterior communicating artery (AcomA); injury to AcomA branches can result in basal forebrain infarction and cognitive dysfunction., Objective: To evaluate anatomic variations of the AcomA basal perforating branches, especially the subcallosal artery (ScA), for clinical implications when approaching the suprachiasmatic subcallosal region from endonasal and transcranial routes., Methods: The origin, course, diameter, and branching pattern of the AcomA's perforating branches were studied in 33 specimens from transcranial and endonasal perspectives., Results: The ScA was present in 79% of the specimens as a single dominant artery arising from the posterior/posterosuperior surface of the AcomA, along with hypothalamic arteries (55%), or as a single artery (24%). It coursed posteriorly towards the lamina terminalis region, curving superiorly to the subcallosal area. The ScA gave off many branches to provide the main blood supply to the subcallosal region. Importantly, it supplies the septal/subcallosal region bilaterally. The ScA can be found posterior, superior, or inferior to the AcomA when using a transylvian, interhemispheric, or endonasal approach, respectively. In specimens with no ScA (21%), the median callosal artery (MdCA) was the dominant artery arising from the AcomA. It followed an identical course to the ScA, providing supply to the same structures bilaterally, but its distal extension reached the body/splenium of the corpus callosum. The MdCA is a ScA variant., Conclusion: The ScA is a unique vessel because it supplies the septal/subcallosal region bilaterally; preservation of this vessel during surgery is crucial for successful outcomes., (Copyright © 2018 by the Congress of Neurological Surgeons.)

Autophagy has been reported to play protective and pathogenetic roles in cerebral ischemia/reperfusion (I/R)-induced neuronal injury. Our previous studies have shown that TP53-induced glycolysis and apoptosis regulator (TIGAR) ameliorates I/R-induced brain injury and reduces anti-cancer drug-induced autophagy activation. However, if TIGAR plays a regulatory role on autophagy in cerebral I/R injury is still unclear. The purpose of the present study is to investigate the role of TIGAR on I/R-induced autophagy activation and ischemic neuronal injury in vivo and in vitro stroke models using TIGAR-transgenic (tg-TIGAR) mice and TIGAR-knockout (ko-TIGAR) mice. The present study confirmed that autophagy was activated after I/R. Overexpression of TIGAR in tg-TIGAR mice significantly reduced I/R-induced autophagy activation and alleviated brain damage, while knockout of TIGAR in ko-TIGAR mice enhanced I/R-induced autophagy activation and exacerbated brain injury in vivo and in vitro. The different activity of autophagy in tg-TIGAR and ko-TIGAR primary neurons after OGD/R were largely reversed by knockdown or re-expression of TIGAR in these neurons. The autophagy inhibitor 3-methyladenine (3-MA) partly prevented exacerbation of brain damage induced by ko-TIGAR, whereas the autophagy inducer rapamycin partially abolished the neuroprotective effect of tg-TIGAR. Knockout of TIGAR reduced the levels of phosphorylated mTOR and S6KP70, which were blocked by 3-MA and NADPH after I/R and OGD/R in vivo and in vitro, respectively. Overexpression of TIGAR increased the levels of phosphorylated mTOR and S6KP70 under OGD/R condition, this enhancement effect was suppressed by rapamycin. In conclusion, our current data suggest that TIGAR protected against neuronal injury partly through inhibiting autophagy by regulating the mTOR-S6KP70 signaling pathway., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Tigertriever (Rapid Medical, Yoqneam, Israel) is a new design of stent retriever., Purpose: To evaluate the feasibility, safety, and efficacy of the Tigertriever in patients with acute ischemic stroke who have undergone mechanical thrombectomy., Materials and Methods: Two different techniques-namely, standard unsheathing (SUT) and repetitive inflation-deflation (RID) techniques, were used. Modified Thrombolysis in Cerebral Infarction (mTICI) scores of 2b and 3 were considered as successful recanalization., Results: A total of 61 thrombectomy procedures with Tigertriever were retrospectively evaluated. The mean age of patients was 60.7 years and their National Institutes of Health Stroke Scale score was 14.7. Overall, the percentage of patients with a mTICI score of 0, 2b, and 3 was 24.6, 26.2, and 49.2, respectively. Successful recanalization and first-pass success rates were 75.4% and 37.7%, respectively. There were no statistical differences between the results of the SUT and RID techniques. No vessel rupture, dissection, or device detachment was observed. The number of patients with a good clinical outcome (modified Rankin Scale score 0-2) was 17 (27.9%)., Conclusion: Our results showed that the Tigertriever device is safe and efficient for mechanical thrombectomy., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Predictors and impact of hemorrhagic transformation (HT) after thrombectomy remain to be elucidated., Objective: To investigate the independent predictors and impact of each hemorrhagic infarction (HI) and parenchymal hematoma (PH) after thrombectomy in patients with acute stroke due to intracranial large vessel occlusion (LVO)., Materials and Methods: We retrospectively reviewed data from 400 patients with acute LVO who underwent thrombectomy. Logistic regression analyses were performed to determine independent predictors of HI and PH on post-treatment CT scans. Associations between HT and poor outcome (modified Rankin Scalescore ≥3) at 90 days were analyzed., Results: HT was observed in 98 patients (62 HIs (15.5%) and 36 PHs (9%)). Independent predictors of HI were male sex, atrial fibrillation, and time from symptom onset to groin puncture. Hyperlipidemia (OR=0.221, 95% CI 0.064 to 0.767, P=0.017) and successful reperfusion (OR=0.246, 95% CI 0.093 to 0.651, P=0.005) were independently associated with a lower chance of PH, while hypertension (OR=2.260, 95% CI 1.014 to 5.035, P=0.046) and longer procedure duration (OR=1.046, 95% CI 1.016 to 1.077, P=0.003) were independently associated with a higher chance of PH. Only PH (OR=10.154, 95% CI 3.260 to 31.632, P<0.001) was an independent predictor of poor outcome., Conclusions: PH is independently associated with poor outcome, whereas HI does not predict outcome after thrombectomy in patients with acute LVO. Our findings suggest that rapid and successful reperfusion is essential to prevent PH in patients undergoing thrombectomy for acute LVO. In addition, our study suggests that hyperlipidemia is associated with a lower risk of PH in such patients., Competing Interests: Competing interests: WY reports being a consultant to Stryker Inc., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: Mechanical thrombectomy (MT) is a highly effective therapy in patients with acute ischemic stroke due to large vessel occlusion (LVO). However, complete recanalization of the occluded vessel cannot be achieved in all patients, leading to poor clinical outcome. We analyzed the reasons for failed recanalization to help direct future improvements in therapy., Methods: 648 consecutive stroke patients with LVO and an MT attempt were retrospectively analyzed for none or minimal recanalization, assessed according to the Thrombolysis in Cerebral Infarction (TICI) score (0/1). Procedural parameters were evaluated in a standardized approach. Among other variables, number of retrieval attempts, devices, duration of the intervention, and rescue methods were analyzed., Results: TICI 0/1 was observed in 72/648 patients (11%). In these patients, the thrombus could not be reached in 21% (n=15/72), was reached but not passed in 21% (n=15/72), and was reached and passed in 58% (n=42/72). Only a minor degree of initial recanalization was achieved in 19% (n=8/42) of patients with a reached occlusion during the course of the intervention. Furthermore, a higher number of passes with a single retriever device led to significant prolongation of the intervention. Therefore, major reasons for failed endovascular recanalization were difficult anatomical access and hard or resistant occlusions that might reflect hard thrombi or pre-existing atherosclerotic stenosis. Procedural complications such as dissection or perforation played a minor role., Conclusion: In stroke patients with failed MT attempts, approximately 60% of occlusions can be passed. In such cases, rescue therapy might be considered to improve recanalization and clinical outcome. Further development of access devices might help in the remaining cases where the microcatheter could not be manipulated to or through the occlusion., Competing Interests: Competing interests: JF served as a consultant for Acandis, Boehringer Ingelheim, Codman, Microvention, Sequent, and Stryker; speaker for Bayer Healthcare, Bracco, Covidien/ev3, Penumbra, Philips, and Sie­mens; and received grants from Bundesministeriums für Wirtschaft und Energie (BMWi), Bundesministe­rium für Bildung und Forschung (BMBF), Deutsche Forschungsgemeinschaft (DFG), European Union (EU), Covidien, Stryker (THRILL study), and Microvention (ERASER study) GT serves as a consultant or speaker for Acandis, Bayer Healthcare, Boehringer Ingelheim, BristolMyersSquibb/Pfizer, Covidien, and Glaxo Smith Kline; served as a lead investigator of the WAKE-UP study; was principal investigator of the THRILL study; and received grants from the Eu­ropean Union (grant No. 278276 and 634809) and Deutsche Forschungsgemeinschaft (SFB 936, Projekt C2). CG received fees as a consultant or lecture fees from Bayer Vital, Boehringer Ingelheim, EBS Technologies, Glaxo Smith Kline, Lundbeck, Pfizer, Sanofi Aventis, Silk Road Medical, and UCB. The other authors have no conflicts of interest., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Nontraumatic nonaneurysmal subarachnoid hemorrhage (SAH) is a rare condition. Among them, SAH with cerebral steno-occlusive disease is quite rare. Moreover there has been no report of SAH patient who had been diagnosed with steno-occlusive disease since before. We here report 2 cases of nontraumatic nonaneurysmal convexity SAH who originally had progressive cerebral steno-occlusive disease. Case 1, a woman in her 40s who had diagnosed left internal carotid artery (ICA) stenosis 6 years before complained of headache. She was diagnosed SAH and progressive ICA stenosis, then performed revascularization. Case 2, a woman in her 40s who had diagnosed right ICA stenosis 7 months before complained of headache. She was diagnosed with SAH and ICA occlusion. These 2 cases suggested that progressive cerebral steno-occlusive disease lead to SAH due to collapse of their fragile pial anastomoses., (Copyright © 2018. Published by Elsevier Inc.)

Background: Endonasal endoscopic approaches (EEA) to the third ventricle are well described but generally use an infrachiasmatic route since the suprachiasmatic translamina terminalis corridor is blocked by the anterior communicating artery (AComA). The bifrontal basal interhemispheric translamina terminalis approach has been facilitated with transection of the AComA. The aim of the study is to describe the anatomical feasibility and limitations of the EEA translamina terminalis approach to the third ventricle augmented with AComA surgical ligation., Methods: Endoscopic dissections were performed on five cadaveric heads injected with colored latex using rod lens endoscopes attached to a high-definition camera and a digital video recorder system. A stepwise anatomical dissection of the endoscopic endonasal transtuberculum, transplanum, translamina terminalis approach to the third ventricle was performed. Measurements were performed before and after AComA elevation and transection using a millimeter flexible caliper., Results: Multiple comparison statistical analysis revealed a statistically significant difference in vertical exposure between the control condition and after AComA elevation, between the control condition and after AComA division and between the AComA elevation and division (p < 0.05). The mean difference in exposed surgical area was statistically significant between the control and after AComA division and between elevation and AComA division (p < 0.01), whereas it was not statistically significant between the control condition and AComA elevation (NS)., Conclusion: The anatomical feasibility of clipping and dividing the AComA through an EEA has been demonstrated in all the cadaveric specimens. The approach facilitates exposure of the suprachiasmatic optic recess within the third ventricle that may be a blind spot during an infrachiasmatic approach.

We previously reported a patient with cerebral proliferative angiopathy (CPA) who showed cerebral ischemia in resting and acetazolamide-stressed N-isopropyl-p-[ 123 I] iodoamphetamine single-photon emission computed tomography ( 123 I-IMP-SPECT). At onset, the patient was treated conservatively. However, during the 2 years following initial onset, his hemiparesis and aphasia had gradually aggravated and his IQ scores were markedly decreased. MRI revealed progressive vascular proliferation and brain atrophy. 123 I-IMP-SPECT showed more severely impaired cerebral blood flow (CBF) and cerebrovascular reactivity over the affected hemisphere. We performed an indirect revascularization to augment CBF; however, his neurological deficits were not improved and new arteriovenous shunts via extracranial-intracranial bypass were developed, followed by an asymptomatic small intracerebral hemorrhage. There are no reports on CPA patients who have shown cerebral hemorrhage after indirect revascularization. Treatments for CPA are still challenging and controversial. Cases with severe stenosis of the proximal arteries may benefit from indirect revascularization. But indirect bypass should not be indicated for such patients without main arterial stenosis, even if they have persistent ischemia., (Copyright © 2018. Published by Elsevier Inc.)

Background: Ischemic symptoms caused by traumatic vertebral artery dissection after cervical maneuvers are treated medically and surgically. This is a report of the infrequently documented occipital to vertebral artery bypass to stop the transient ischemic attacks following traumatic vertebral artery dissection., Case Description: A 33-year-old man presented with a sudden right posterior neck pain following a sudden neck movement, accompanied by left lower quadrant anopsia and rotational vertigo. The neurologic symptoms had already been resolved on arrival. Magnetic resonance imaging and digital subtraction angiography revealed an extracranial vertebral artery dissection with no evidence of cerebral infarction. Although medical therapy was initiated, he repeatedly complained of ischemic symptoms. A bypass was performed from the occipital artery to the atlas loop of the vertebral artery with distal occlusion of the lesion. The patient was neurologically intact after the surgery, and magnetic resonance imaging showed no cerebral infarction., Conclusion: A bypass from the occipital artery to the atlas loop of the vertebral artery is an effective procedure for traumatic extracranial vertebral artery dissection with ischemic symptoms., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Embolization of arteriovenous malformations is characteristically used as part of a multimodal treatment approach, pre-operatively to facilitate microsurgical resection or as a preradiosurgical adjunct. The concept of AVM cure via embolization alone has gained popularity in recent years. Embolization of AVMs has been most commonly performed transarterially, with the transvenous route traditionally eschewed given concern over precipitating premature venous occlusion and consequent hemorrhage. However, the transvenous approach in treating AVMs offers several distinct advantages compared to the transarterial route and can be used in instances when the latter is not feasible, with several series having proven its efficacy and safety. Conceptually, AVM embolization performed via the transvenous route achieves complete obliteration by directly and facilely targeting the nidus. Nidal embolisate penetration is facilitated by control of arterial inflow via systemic or local hypotension. Innovation in endovascular strategies has led to significantly improved obliteration rates. The experience with transvenous AVM embolization is reviewed and discussed., (Copyright © 2018. Published by Elsevier B.V.)

There are still different descriptions of the segmentation of the posterior cerebral artery, although there is a radiological and anatomical consensus on the segmentation of the anterior and the middle cerebral artery. This study aims to define the most appropriate localization for origin and end points of the segments through reviewing the segmentation of the posterior cerebral artery. The segments and the cortical branches originating from those segments of the 40 posterior cerebral arteries of 20 cadaver brains were examined under operating microscope. In this research, the P 1 , P 2 , P 3 , P 4 , and P 5 classification of the segmentation of the posterior cerebral artery is redefined. This redefinition was made to overcome the complexities of previous definitions. The P 1 segment in this research takes its origin from the basilar tip and ends at the junction with the posterior communicating artery. The average diameter of this segment at the origin was 2.21 mm (0.9-3.3), and the average length was 6.8 mm (3-12). The P 2 segment extends from the junction with the posterior communicating artery to the origin of the lateral temporal trunk. This point usually situates on one level of posterior of the cerebral peduncle. The average diameter of this segment at the origin was 2.32 mm (1.3-3.1), and the average length was 20.1 mm (11-26). The P 3 segment extends from the origin of the lateral temporal trunk to the colliculus where both the posterior cerebral arteries are the nearest to each other (quadrigeminal point) and is located at the anterior-inferior of the splenium. The average diameter of this segment at the origin was 1.85 mm (1.2-2.7), and the average length was 16.39 mm (9-28). The P 4 begins at the quadrigeminal point and ends at the top of the cuneus. The average diameter of this segment at the origin was 1.55 mm (1.1-2.2). While the P 5 segment is named as the terminal branches of the major terminal branches of the posterior cerebral artery, no definite border was found between the P 4 and the P 5 segments. In this study, the segmentation of the posterior cerebral artery, developed by Krayenbühl and Yaşargil, was redefined to be more appropriate for radiological and anatomical purposes.

Aim: To assess the safety and efficacy of mechanical thrombectomy (MT) with stent-retrievers in anterior circulation stroke (ACS) patients due to the occlusion of major cerebral arteries, and to compare the results achieved in patients on oral anticoagulation (OAC) and those not on OAC., Materials and Methods: The present retrospective study comprised 285 consecutive patients (115 males; mean age 74±13 years). The following data were collected: baseline characteristics, occurrence of risk factors, pre-event treatment with OAC, neurological deficit at the time of treatment, time to therapy, recanalisation rate (successful recanalisation defined as Thrombolysis in Cerebral Infarction score ≥2b), post-treatment imaging findings. The 90-day clinical outcome was assessed using modified Rankin scale (good outcome defined as 0-2)., Results: The following statistically insignificant differences were found in 26 patients on OAC versus 259 patients without OAC: occurrence of symptomatic intracerebral haemorrhage 7.7% versus 8.1%, achievement of successful recanalisation 69.2% versus 82.6%, good 90-day clinical outcome 34.6% versus 56.8%, 90-day mortality 26.9% versus 20.8% (p>0.05 in all cases). Age and neurological deficit at the time of treatment were identified as independent negative predictors of good 90-day clinical outcome (odds ratio [OR]=0.90, 95% confidence interval [CI]: 0.88-0.94 and OR=0.83, 95% CI: 0.77-0.90, respectively) and as independent positive predictors of mortality (OR=1.12, 95% CI: 1.06-1.18 and, OR=1.17, 95% CI: 1.07-1.27, respectively; p<0.05 in all cases)., Conclusions: MT with stent-retrievers is safe and effective in ACS patients on OAC., (Copyright © 2018 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.)

We describe the unique case of a 6-year old boy who presented with recalcitrant generalized tonic-clonic seizures and clinicoradiological features of congenital Cirsoid aneurysm. The lesion was supplied by occipital arteries and a large right parietal parasagittal intracranial feeding artery in a Yokouchi type C pattern. The venous drainage was communicating with the posterior part of the superior sagittal sinus. Six months after successful ligation of the feeding arteries and complete surgical excision of the lesion, the patient remains seizure free.

Objective: Recent three-dimensional constructive interference in steady state (3D-CISS) studies have shown that the involved arteries decrease not only their own luminal caliber but also outer diameter in moyamoya disease (MMD). This study was aimed to clarify how the outer diameter of the involved arteries serially change during disease progression in MMD using qunatitaive 3D-CISS imaging., Methods: This study included 8 hemispheres of 7 patients with MMD whose Suzuki angiographic stage spontaneously progressed during follow-up. Using 3D-CISS, the outer diameter was quantified serially in supraclinoid portion of internal carotid artery (C1), the horizontal portion of middle and anterior cerebral arteries (M1 and A1, respectively) before and after the spontaneous disease progression, and also 3-12 months later., Results: In 7 hemispheres with early disease stage (stage 1-3) at initial presentation, the involved arteries decreased in their outer dimater in parallel with luminal stenosis during spontaneous disease progression in the C1 (P = 0.005), M1 (P < 0.0001), and A1 portions (P = 0.0048). In the remaining 1 hemisphere with stage 4 at initial presentation, 3D-CISS imaging showed no significant change in the outer diameter of C1, M1, and A1 segments during disease progression., Conclusions: Using quantitative 3D-CISS imaging, this study clearly shows that the involved arteries serially decrease in their own outer diameter in parallel with luminal stenosis during spontaneous disease progression in early stages of MMD (stage 1-3). This phenomenon has not been reported previously and may result from the pathognomic mechanisms underlying the development of MMD., (Copyright © 2018 Elsevier Inc. All rights reserved.)

One of the main difficulties in intracranial aneurysms (IA) surgery refers to the choice of the appropriate clip(s) to be implanted. Although the imaging exams currently available ensure visualization of IA's morphology, they do not bring an accurate reference positioning for the surgeon in executing the surgery procedure nor efficiently contribute to planning the surgery. Unfortunately, for IA's largely inaccessible regions, there is not an efficient method of treatment planning. Therefore, we propose a novel method that allows the generation of a 3D biomodel of the IA region under investigation using additive manufacturing technology (AM). Thus, a physical copy of the IA is produced and offers the surgeon a full view of the anatomy of that region of the brain. The aim of this study is the creation of a flexible 3D physical model (elastomer) through the AM technique, in order to allow the clip selection prior to the surgery. DICOM angio-CT images from eight patients who underwent IA surgery were transformed into STL format and then built on a 3D printer. Preoperative surgical clip selection was performed and then compared with those used in surgery. At the end of the study, all 3D IA biomodels were reproduced for microsurgical clipping selection and it was possible to predict the metal clip to be used in the surgery. In addition, the proposed methodology helps to clarify the surgical anatomy and to avoid excessive manipulation of the intracranial arteries and prolonged surgical time. The major advantage of this technology is that the surgeon can closely study complex cerebrovascular anatomy from any perspective using realistic 3D biomodels, which can be handheld, allowing simulation of intraoperative situations and anticipation of surgical challenges., (© 2018 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)

Objective: The present study was conducted to explore the value of 3-dimensional microscope integrated extravascular optical coherence tomography (OCT) as the first suitable intraoperative imaging modality of cerebral aneurysm (CA) and parent vessel wall morphology., Methods: Incidental CAs (n = 16) of the anterior circulation with indication for microsurgical clipping were scanned., Results: Analysis revealed that intraoperative OCT achieved to delineate the microstructural composition of the parent vessel in all cases and the CA wall in 68.8%. Clinical relevant characteristics such as thickness, calcification, residual tunica media, and atherosclerotic plaque of CA wall could be demonstrated with high image quality approaching the spatial resolution of histopathology., Conclusion: Our findings demonstrate that intraoperative OCT may hold promise as an additional imaging tool during neurovascular procedures., (© 2019 S. Karger AG, Basel.)

OBJECTIVE The occipital artery (OA) is a frequently used donor vessel for posterior circulation bypass procedures due to its proximity to the recipient vessels and its optimal caliber, length, and flow rate. However, its tortuous course through multiple layers of suboccipital muscles necessitates layer-by-layer dissection. The authors of this cadaveric study aimed to describe a landmark-based novel anterograde approach to harvest OA in a proximal-to-distal "inside-out" fashion, which avoids multilayer dissection. METHODS Sixteen cadaveric specimens were prepared for surgical simulation, and the OA was harvested using the classic (n = 2) and novel (n = 14) techniques. The specimens were positioned three-quarters prone, with 45° contralateral head rotation. An inverted hockey-stick incision was made from the spinous process of C-2 to the mastoid tip, and the distal part of the OA was divided to lift up a myocutaneous flap, including the nuchal muscles. The OA was identified using the occipital groove (OG), the digastric muscle (DM) and its groove (DG), and the superior oblique muscle (SOM) as key landmarks. The OA was harvested anterogradely from the OG and within the flap until the skin incision was reached (proximal-to-distal technique). In addition, 35 dry skulls were assessed bilaterally (n = 70) to study additional craniometric landmarks to infer the course of the OA in the OG. RESULTS The OA was consistently found running in the OG, which was found between the posterior belly of the DM and the SOM. The mean total length of the mobilized OA was 12.8 ± 1.2 cm, with a diameter of 1.3 ± 0.1 mm at the suboccipital segment and 1.1 ± 0.1 mm at the skin incision. On dry skulls, the occipitomastoid suture (OMS) was found to be medial to the OG in the majority of the cases (68.6%), making it a useful landmark to locate the OG and thus the proximal OA. CONCLUSIONS The anterograde transperiosteal inside-out approach for harvesting the OA is a fast and easy technique. It requires only superficial dissection because the OA is found directly under the periosteum throughout its course, obviating tedious layer-by-layer muscle dissection. This approach avoids critical neurovascular structures like the vertebral artery. The key landmarks needed to localize the OA using this technique include the OMS, OG, DM and DG, and SOM.

Aneurysms of vertebral (VA) and posterior inferior cerebellar arteries (PICA) are relatively rare pathologies and account for 3.4% of the total number of intracranial aneurysms., Material and Methods: The experience of microsurgical treatment of 67 patients with VA and PICA aneurysms in N.N. Burdenko National Medical Research Center for Neurosurgery of the RF Ministry of Health from 2012 to 2017 is presented., Results: Most patients underwent reconstructive microsurgical interventions: clipping of the aneurysm neck in 42 (62.7%) patients and complex clipping with the formation of arterial opening - in 10 (14.9%). Exclusion of the aneurysm together with the carrier artery (trapping, proximal clipping) was performed on 10 (14.9%) patients. In 5 (7.5%) patients, deconstruction of the carrier artery of the aneurysm was performed after creating local anastomoses. The radical exclusion of aneurysms in the studied group was 95.5%. Postoperative dysfunction of the caudal group of cranial nerves was detected in 11 (16.4%) patients. There were no lethal outcomes, or cases with vegetative status outcomes., Conclusion: Microsurgical intervention is an effective way to treat VA and PICA aneurysms, subject to the principles of patient selection based on existing treatment algorithms as well as adherence to an interdisciplinary approach.

Background and Purpose: To describe our first experience using a small stent retriever specifically designed for thrombectomy in cerebral arteries with a small caliber (Acandis APERIO ® 3.5/28) in patients with acute ischemic stroke., Materials and Methods: All patients with an acute ischemic stroke, who underwent endovascular recanalization using the APERIO ® thrombectomy device with a diameter of 3.5 mm, were identified in retrospect and included in the present analysis. Demographic and clinical data as well as data on the procedures performed were collected (patient sex, mean age, NIHSS, mRS, TICI score, and complications)., Results: Stent retriever-based thrombectomy with the Aperio ® 3.5/28 alone (n = 10 vessels) or in combination with other devices (n = 13 vessels) was performed in 22 acute stroke patients with embolic occlusions of distal branches of the anterior and posterior circulations (median NIHSS = 8.5). For vessels treated with the Aperio ® 3.5/28, we achieved a TICI 2b/3 reperfusion rate of 73.9%. One patient suffered a symptomatic intracerebral hemorrhage after thrombectomy; otherwise, no procedure-related complications were seen., Conclusion: Our data suggest that mechanical thrombectomy of distal cerebral artery occlusions with the Aperio ® 3.5/28 is feasible and in general safe, thus offering a promising option for endovascular stroke therapy. However, multicentric studies with larger patient cohorts are necessary to evaluate the clinical benefit.

Background: A properly placed clip may slip off the aneurysm during the postoperative period. Many factors have been attributed to this complication, although clip adherence to the dural stitch has not been reported., Materials and Methods: Following the single occurrence of such unusual complication, 64 similar medial cerebral artery (MCA) aneurysms were retrospectively investigated at a single institution. Clip adherence to the dura demonstrated in early postoperative computed tomography (CT) was a presumed factor of a late clip migration in this study., Results: In the series, there were 4 (6.3%) aneurysm remnants and 1 slipped clip that firmly adhered to the dura. In this particular case, the revision surgery revealed the spring coil firmly adhering to the dura in the previous suture line. Neither the occurrence of an aneurysm neck remnant nor clip slippage were related to the clip's adherence to the dura in the analysis of the entire group (p > 0.05). On the contrary, application of a fenestrated clip did contribute to that finding in multivariate analysis (p < 0.01). Unlike the rest, two surgeons unintentionally tended to position the clip close to the dura (p < 0.01). The clip-to-dura distance measured in the follow-up CT angiography 1 year after the surgery differed from that in the postoperative CT in 83.8% of the cases and decreased by an average of 0.5 mm., Conclusions: Clip-to-dura adherence should be regarded as a normal finding in the postoperative CT following MCA aneurysm clipping. Surgeons should consider the possibility of clip head protrusion into the dural stitch line.

Background: Rapid development of new devices and techniques in endovascular neurosurgery allows treatment of complex intracranial vascular lesions. These treatments, however, are not without risk. We report a case of unusual vascular laceration during stent-assisted coiling of a posterior inferior cerebellar artery (PICA) aneurysm., Case Presentation: A 75-year-old female with a recurrent, previously coiled PICA aneurysm developed avulsion of the parent vessel followed by fatal bleeding while an attempt was made to place a microcatheter across the aneurysmal neck for stent-assisted coiling., Conclusions: Pathological examination was performed to understand the mechanism of the rupture. The most likely mechanism was straightening of the significant vascular tortuosity, excessive tension on the vessel origin and avulsion upon advancement of the microcatheter over the microguidewire.