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Background and Objectives: Neurosurgeons need a profound knowledge of the surgical anatomy of the cerebral arteries to safely treat patients. This is a challenge because of numerous branches, segments, and tortuosity of the main blood vessels that supply the brain. The objective of this study was to create high-quality three-dimensional (3D) anatomic photorealistic models based on dissections of the brain arterial anatomy and to incorporate this data into a virtual reality (VR) environment., Methods: Two formaldehyde-fixed heads were used. The vessels were injected with radiopaque material and colored silicone and latex. Before the dissections, the specimens were computed tomography scanned. Stratigraphical anatomic dissection of the neck and brain was performed to present the relevant vascular anatomy. A simplified surface scanning method using a mobile phone-based photogrammetry application was used, and the data were incorporated into a VR 3D modeling software for post-processing and presentation., Results: Fifteen detailed layered photorealistic and two computed tomography angiography-based 3D models were generated. The models allow manipulation in VR environment with sufficient photographic detail to present the structures of interest. Topographical relevant anatomic structures and landmarks were annotated and uploaded for web-viewing and in VR. Despite that the VR application is a dedicated 3D modeling platform, it provided all necessary tools to be suitable for self-VR study and multiplayer scenarios with several participants in one immersive environment., Conclusion: Cerebral vascular anatomy presented with photogrammetry surface scanning method allows sufficient detail to present individual vessel's course and even small perforating arteries in photorealistic 3D models. These features, including VR visualization, provide new teaching prospects. The whole study was done with simplified algorithms and free or open-source software platforms allowing creation of 3D databases especially useful in cases with limited body donor-based dissection training availability., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

A persistent stapedial artery originates from the petrous segment of the internal carotid artery due to failure of the regression of the embryonic stapedial artery. During embryologic development, the stapedial artery supplies the middle meningeal artery through the ventral pharyngeal artery. The presence of a persistent stapedial artery can result in direct communication between the basilar and middle meningeal arteries. We present a cerebral angiogram image of an adult patient that shows a right-sided persistent stapedial artery with communication between the right middle meningeal and basilar arteries. It is important to recognize such rare anatomic variants during endovascular interventions to avoid catastrophic complications such as nontarget embolization of the posterior circulation., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objective: To present a retrospective review of a single-institute experience with bypass surgery of complex anterior cerebral artery aneurysm., Methods: Eight patients (5 females and 3 males; mean age, 34.2 years) with complex anterior cerebral artery aneurysms were treated with bypass. There were 3 precommunicating aneurysms, 1 communicating artery aneurysm, and 4 postcommunicating aneurysms (2 in A2 and 2 in A3). A3-A3 side-to-side in situ bypass was performed in 6 cases. A3-radial artery-A3 interpositional bypass was performed in 1 case with A3 segments located far apart, and A3-A3 transplantation was performed in 1 case with nonparallel aligned A3 segments. Of the 8 aneurysms, 3 were secured with proximal clipping, 1 was secured with distal clipping, 1 was secured with direct clipping, 1 was secured with isolation, and 2 were secured with embolization., Results: Aneurysm obliteration was achieved in all cases. Only 1 in situ bypass from a smaller donor artery to a larger recipient artery failed with minor postoperative infarction. Intraoperative bleeding from the site of anastomosis occurred in 1 case during embolization. All patients had complete recovery with normal neurological function during follow-up at outpatient clinics., Conclusions: We established a simplified surgical algorithm for complex anterior cerebral artery aneurysms based on the geometrical and spatial relationship between efferent arteries. The reasons for bypass failure and hemorrhagic complication were also discussed., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Fenestrations of cerebral arteries are congenital variants that develop when primitive vessels fuse incompletely. An association between the incidence of aneurysm and a fenestrated artery has been noted in the radiological literature. However, technical limitations of radiological studies may hamper visualization of small fenestrations and aneurysms. We sought to analyze a large, postmortem collection of human brains to assess the association between aneurysm formation and the presence of fenestrations., Methods: This study included 333 formalin-fixed brains. The arachnoid was dissected under a microscope, the cerebral arteries were completely exposed, and fenestrations and aneurysms were identified and measured. For each specimen, age, sex, and all vascular abnormalities and variations were recorded for analysis., Results: Fenestrations were present in 41% of the specimens, and 37% of these were multiple. Fenestrations were 3.1 ± 2.5 mm long and most commonly occurred in the anterior communicating artery (63%). Aneurysms were present in 8% of the specimens, usually in the anterior communicating artery or the middle cerebral artery. An aneurysm correlated with a fenestration was detected in 2% of all specimens (n = 4) and was not statistically significant (P = 0.18)., Conclusions: Fenestrations of the intracranial arteries are a common anatomical finding. They are present most often in the anterior communicating artery. Most aneurysms were detected in the anterior communicating artery and middle cerebral artery. We conclude that the existence of an aneurysm in a fenestrated artery is an incidental, rather than causal, relationship., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Endoscopic endonasal surgery has proved to offer a practical route to treat suprasellar lesions, including tumors and vascular pathologies. Understanding the different configurations of the anterior cerebral communicating artery (ACoA) complex (ACoA-C) is crucial to properly navigate the suprachiasmatic space and decrease any vascular injury while approaching this region through an endonasal approach., Methods: An endoscopic endonasal transplanum-transtubercular approach was performed on 36 cadaveric heads (72 sides). The variations of the ACoA-C and feasibility of reaching its different components were analyzed. The surgical area exposure of the lamina terminalis was also quantified before and after mobilization of the ACoA-C., Results: The typical ACoA-C configuration was found in 41.6% of specimens. The following 2 main variations were identified: accessory anterior cerebral artery segment 2 (5, 13.9%) and common trunk of anterior cerebral artery with absence of ACoA (5, 13.9%). Of 101 recurrent arteries of Heubner, 96 (95.0%) were identified within 4 mm proximal or distal to the ACoA. The mean lamina terminalis exposure area was 33.1 ± 16.7 mm 2 , which increased to 59.9 ± 11.9 mm 2 after elevating the ACoA., Conclusions: A considerable amount of variation of the ACoA-C can be found through an endoscopic endonasal transplanum-transtubercular approach. These configurations determine the feasibility of lamina terminalis exposure and the complexity of reaching the ACoA. Assessment of ACoA morphology and its adjacent structures is crucial while approaching the suprachiasmatic through a transnasal corridor., (Copyright © 2021. Published by Elsevier Inc.)

Background: The transcirculation approach (TCA) for stent-assisted coiling (SAC) of intracranial aneurysms may be useful for certain wide-neck bifurcation aneurysms as well as those with acute-angle efferent branches., Objective: To describe a multicenter experience using the TCA for SAC., Methods: A multicenter, retrospective study (2016-2020) of aneurysm treatment using SAC via the TCA. Angiographic outcome was scored using the Raymond Scale (adequate occlusion 1 and 2), and clinical outcome was scored using a modified Rankin Scale (good outcome 0-2) RESULTS: Twenty-nine patients with 29 aneurysms were included (62.1% female; average age 61; 89.7% unruptured; 13.8% previously treated; average dome size 6.4 mm; average neck 4.4 mm). Aneurysm locations included internal carotid artery-fetal posterior cerebral artery (n=4), internal carotid artery terminus (n=4), anterior communicating artery (n=8), vertebral artery-posterior inferior cerebellar artery (n=2), and basilar tip (n=11). The TCA used communicating arteries (93.1%; average 1.6 mm), intermediate catheters (51.7%), jailing technique (62.1%), and staged procedures (10.3%). The most common stent was the Neuroform Atlas (Stryker; 69%). Immediate adequate occlusion was obtained in 75.9%, and five patients with inadequate occlusion progressed to adequate occlusion at follow-up. One (3.4%) procedural complication occurred: a watershed stroke in the setting of baseline four-vessel extracranial disease. Two patients had a poor outcome unrelated to the TCA. The majority of patients (86.4%) had a good clinical outcome. One case of in-stent stenosis due to non-compliance with medication was seen, which resolved with medication resumption., Conclusions: The TCA for SAC can be performed for a variety of aneurysms with a low complication rate and good clinical outcomes., Competing Interests: Competing interests: JRM: Compensated for lectures for Penumbra and PMI. MRL: Educational grants from Stryke, Medtronic, Philips volcano; equity interest in Synchron, Cerebrotech, Eloupes; adviser for Metis Innovative; consultant for Medtronic. CJG: Consultant to Stryker; research funding from Medtronic. LJK: Stock ownership, Spi Surgical, LLC. BG: Consultant for Medtronic and MicroVention. AA: Consultant for Stryker. BJ: Consultant for Stryker, Medtronic. RG: Consultant to BALT Neurovascular, Medtronic, Cerenovus. CMS: Research support: Penumbra; ownership; Neurotechnology investors., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Goyal et al described occlusions in M2/3, A2/3 and P2/3 as medium vessel occlusions (MeVOs); the only available controlled data of mechanical thrombectomy (MT) in MeVOs is limited to the middle cerebral artery M2 segment, suggesting that MT may be effective and safe with high functional independence and recanalization rates. The Stent retriever Assisted Vacuum-locked Extraction (SAVE) technique in mechanical thrombectomy consists of the simultaneous use of a stent retriever and a distal aspiration catheter (DAC), with the removal of both as a unit when performing the thrombectomy pass; however, so far the low-profile (0.035 inch distal inner diameter) DACs were longer (160 cm) than conventional 0.017 inch microcatheters for MeVOs. We present a case of a combined approach MT in MeVO with the use of the new 167 cm long NeuroSlider 17 (Acandis, Pforzheim, Germany) 0.0165 inch microcatheter and 3MAX (Penumbra, Alameda, CA) through the SAVE technique-the MeVO SAVE technique. (video 1). neurintsurg;13/8/768/V1F1V1video 1., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: Cirsoid aneurysms are rare arteriovenous malformations of the scalp that present with disfigured pulsatile masses and may be associated with headache, bleeding, or tinnitus. These lesions are difficult to manage because of their complex vascular anatomy, high shunt flow, and cosmetic disfigurement; many options have been described to treat such lesions. We evaluate 10 years' experience in the surgical management of cirsoid aneurysms of the scalp., Methods: This study included 15 patients with cirsoid aneurysm of the scalp, all of whom were treated with surgical excision only over 10 years. They were 8 females and 7 males, with a median age of 23 years. History of trauma was present in 5 patients. Frontal and parietal regions were the commonly affected sites. Superficial temporal, supraorbital, and occipital arteries were the most frequent feeding arteries., Results: Excision of the lesion was performed in all patients using our modified surgical technique. All patients had good cosmetic results and there were no recurrences during an average follow-up of 25 months., Conclusions: Despite great progress in endovascular therapy, surgical excision of cirsoid aneurysms of the scalp seems to be the most effective treatment, with good results and patient satisfaction., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: A bypass is usually required to prevent ischemia during the treatment of anterior inferior cerebellar artery (AICA) aneurysms. The intracranial (IC)-to-IC bypass provides several advantages over the extracranial-to-IC bypass in the posterior fossa. However, there are only 2 case reports about AICA revascularization with the posterior inferior cerebellar artery (PICA). We aimed to investigate the microsurgical anatomical challenges for PICA to AICA anastomosis., Methods: Ten cadaveric heads injected with colored silicone were inspected on both sides using a lateral transcondylar approach. After the donor and recipient arteries were examined from the posterior side, neurovascular contents of the posterior fossa were excised and the origin, course, and variations of both arteries were investigated from the anterior view. The diameters of the AICA and PICA segments and the intersegment distance were measured., Results: PICA variations and posteromedial origins from the vertebral artery were identified in 8 of the 20 right and 6 of the 20 left sides, and the first segment of the PICA was not present in 7 sides. Furthermore, in 18 sides, the PICA was trapped between the lower cranial nerves and dentate ligaments. Therefore the donor artery could not be brought closer than 1 cm to the recipient artery in 19 sides. Moreover, AICA variations were identified in 6 sides, and in 12 sides, the diameter of the recipient artery was <1 mm., Conclusions: The mostly PICA-related issues made PICA-to-AICA anastomosis unfeasible in all cadaveric heads included in the study., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objective: Despite failure of the EC/IC Bypass Study Group to demonstrate effectiveness in minimizing future stroke events, superior temporal artery-medial cerebral artery (STA-MCA) bypass remains an essential treatment for complex giant intracranial aneurysms, tumors, moyamoya disease with ischemia, and atherosclerotic steno-occlusive disease with hemodynamic cerebrovascular insufficiency. The objective of this report is to describe a novel suturing technique for STA-MCA bypass that helps reduce donor-recipient anastomosis time, allowing for a well-organized systematic workflow., Methods: Step 1 involves passing the needle of a 9-0 polypropylene suture from out-to-in on the donor vessel followed by in-to-out on the recipient vessel. Step 2: Before cutting and tying a knot as per the established method of suturing, repeat step 1 and leave the needle "parked", creating a loop that is then cut at its proximal end. Step 3: Tie knots using the jeweler's forceps. Repeat previous steps until there are enough throws to seal the bypass adequately., Results: The STA-MCA bypass serves as a principal method for flow augmentation. The technique described here allows for more efficient and organized microsurgical movements reducing vessel tissue manipulation and clamp time., Conclusions: We describe a novel technique for interrupted STA-MCA bypass suturing that adds efficiency, safety, organization, and operative ease compared with the conventional method of interrupted vessel suturing., (Published by Elsevier Inc.)

Introduction: Microvascular decompression with transposition of the involved vessels provides good surgical outcomes in cases of complex and recurrent neurovascular compression syndromes. We conducted a literature review to illustrate the variations in the surgical techniques used for transposition and to provide a practical decision-making scheme for transposition of the involved vessel., Methods: A PubMed Medline database record search was conducted using the following algorithm ("Microvascular Decompression Surgery"[Mesh]) OR (((Microvascular) OR (Macrovascular)) AND decompression AND surgery) AND (transposition). Only articles that detailed the intraoperative techniques were included., Results: A total of 48 articles were included. The adjacent anatomical walls to which the compressing vessel can be anchored were divided into 4 groups; A: roof (tentorium cerebelli), B: anterior wall (posterior surface of petrous bone and clivus), C: posterior wall (petrosal surface of the cerebellum), and D: "no wall" required. A new decision-making scheme based on the following 2 questions was designed: 1) is the conflicting vessel amenable to transposition to a nearby wall in the cerebello-brainstem space? 2) what is the closest wall to secure the transposed vessel?, Conclusions: Transposition of the involved vessel is a valuable procedure for microvascular decompression of the posterior fossa cranial nerves. Anchoring the vessel to the adjacent anatomical wall ensures secure transposition. The proposed algorithm provides a systemic scheme to identify the optimal anatomical wall, and to determine the technique and material that can be used to anchor involved vessel. This scheme is an efficient method to inform the intraoperative decision-making process., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Purpose:  To explore factors affecting the prognosis of choroidal anterior artery aneurysm (AChAA) and provide a reference for improving the postoperative outcome., Methods:  The clinical data of 86 patients with AChAA who underwent treatment by a single surgeon were collected and analyzed retrospectively. Univariate analysis and multivariate logistic regression analysis were conducted to examine 12 factors that possibly affected outcome., Results:  The five factors that affected the patient outcomes were times of subarachnoid hemorrhage (SAH), characteristics of SAH on computed tomography (CT), Hunt-Hess grade, aneurysm size, and presence or absence of postoperative complications. Characteristics of SAH on CT (odds ratio [OR]: 3.727; p  = 0.000; 95% confidence interval [CI], 1.850-7.508), aneurysm size (OR: 6.335; p  = 0.000; 95% CI, 2.564-15.647), and presence or absence of postoperative complications (OR: 4.141; p  = 0.000; 95% CI, 1.995-8.599) were independent risk factors influencing the prognosis. In addition, the incidence of postoperative ischemia (caused by anterior choroidal artery syndrome) is related to the aneurysm emitting part and presence or absence of intraoperative rupture., Conclusions:  The analysis of characteristics of SAH on CT, aneurysm size, and presence or absence of postoperative complications can roughly determine the outcome of patients with AChAAs., Competing Interests: None declared., (Thieme. All rights reserved.)

Knowledge of the blood supply to the pituitary gland is important for clinicians and surgeons. Therefore, a good working knowledge of this anatomy is important. The goal of this article was to review current anatomic knowledge of the blood supply to the pituitary gland and its clinical relevance., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objective: To study the surgical anatomy of the labyrinthine artery (LA) and the subarcuate artery (SA), their anatomic relationships, and clinical implications, as injury of the LA can result in hearing loss., Methods: Ten formalin-fixed, latex-colored specimens were studied (20 sides). After retrosigmoid craniotomy and neurovascular dissection under microscopic magnification, 4-mm 0° and 30° endoscopic lenses were used to improve visualization. Results were statistically analyzed., Results: The LA was a constant artery that followed the vestibulocochlear nerve into the internal auditory canal. The SA was an inconstant artery that ended in the dura mater around the subarcuate fossa in 35% of cases. The LA originated from the anterior inferior cerebellar artery in 89.3% of specimens and from the basilar artery in 10.7% of specimens. The SA branched off from the anterior inferior cerebellar artery when present. The origin of the LA was inferomedial to the vestibulocochlear nerve in most cases (71.4%), whereas the SA was usually lateral (70%). The distal portion of the LA was inferomedial to the vestibulocochlear nerve in 71.4% of cases. The distal portion of the SA was superolateral to the nerve in all cases (P < 0.00001)., Conclusions: Knowledge of the different trajectory and anatomic relationship of the LA and the SA with the vestibulocochlear nerve is of paramount importance to differentiate them during surgery. The LA is usually inferomedial to the vestibulocochlear nerve at its distal and proximal aspects, whereas the SA usually originates lateral and ends superolateral to the nerve., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Introduction: Clinically, anterior communicating artery complex fenestration combined with fenestration-related aneurysms is rare, and combination of this condition with tandem aneurysms is even rarer., Patient Concerns: A case of a 43-year-old man with spontaneous subarachnoid hemorrhage., Diagnosis: A computed tomography angiography examination revealed a fenestrated anterior communicating artery complex combined with 2 aneurysms. Then, a digital subtraction angiography examination was performed to further determine the diagnosis, which showed a complex anatomical structure of the local tissue. After the aneurysms ruptured, they were partially wrapped by a hematoma and compressed, which increased the difficulty of surgery., Interventions: An endovascular interventional therapy method was chosen, and a simple coil was successfully inserted through the blood vessel into the tandem aneurysms to maintain the integrity of the anatomical structure., Outcomes: The patient recovered well postoperatively. An imaging review after the operation did not show the aneurysms, and the upper and lower branches were patent., Conclusion: Therefore, endovascular treatment is an appropriate choice for arterial fenestration combined with tandem aneurysms, once the aneurysms have ruptured.

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.)

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.)

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.)

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.)

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.

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.)

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.)

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.)

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.