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Various devices exist for glioma image-guided surgery to improve tumor resection. These devices work as stand-alone units, making the flow of operative information complicated and disjointed. A novel networked operating room, the Smart Cyber Operating Theater (SCOT), has been developed, integrating stand-alone medical devices using the OPeLiNK communication interface. We report and evaluate the impact of SCOT for glioma surgery and our initial experiences.Patients with gliomas who underwent tumor resection in SCOT between July 2018 and June 2021 were retrospectively reviewed. Various types of intraoperative information were integrated, managed, and shared with the surgical strategy desk using OPeLiNK. Patients' demographics, tumor characteristics, treatment details, and outcomes were obtained. The impact of the SCOT system was evaluated.Twenty-seven patients, with a mean age of 48.6 years (range, 13-88 years), met the inclusion criteria. We successfully completed all the surgical procedures using SCOT. The mean operation time was 420.6 minutes (range, 225-667 minutes).Gross total resection was accomplished in 13 patients (48.1%), subtotal resection in 4 (14.8%), and partial resection in 10 (37.0%). The main surgeon in the operating room and other neurosurgeons at the strategy desk shared and discussed the information in real time during the procedures.The use of SCOT was shown to be safe and feasible in glioma surgery. This study suggests that SCOT may improve surgical outcomes and educational impact by sharing information in real time with the strategy desk.

Meningiomas rarely progress to malignant variants and there is no consensus regarding the period over which malignant transformation may occur. Here, we report a case of anaplastic meningioma that showed malignant transformation 18 years after gross total resection of benign meningioma in the primary surgery, which may be the longest duration reported to date. Although the recurrence rate is low following total resection of benign meningioma, malignant transformation can rarely occur after a long period as in our case. Long-term follow-up after total resection of benign meningioma is suggested considering the risk of malignant transformation.

BACKGROUND: Radial artery access for cerebral angiography is traditionally performed in the wrist. Distal transradial access in the anatomic snuffbox is an alternative with several advantages. PURPOSE: Our aim was to review the safety and efficacy of distal transradial access for diagnostic cerebral angiography and neurointerventions. DATA SOURCES: We performed a comprehensive search of the literature using PubMed, Scopus, and EMBASE. STUDY SELECTION: The study included all case series of at least 10 patients describing outcomes associated with distal transradial access for diagnostic cerebral angiography or a neurointervention. DATA ANALYSIS: Random-effects models were used to obtain pooled rates of procedural success and complications. DATA SYNTHESIS: A total of 7 studies comprising 348 (75.8%) diagnostic cerebral angiograms and 111 (24.2%) interventions met the inclusion criteria. The pooled success rate was 95% (95% CI, 91%–98%; I(2) = 74.33). The pooled minor complication rate was 2% (95% CI, 1%–4%; I(2) = 0. No major complications were reported. For diagnostic procedures, the combined mean fluoroscopy time was 13.53 [SD, 8.82] minutes and the mean contrast dose was 74.9 [SD, 35.6] mL. LIMITATIONS: A small number of studies met the inclusion criteria, all of them were retrospective, and none compared outcomes with proximal transradial or femoral access. CONCLUSIONS: Early experience with distal transradial access suggests that it is a safe and effective alternative to proximal radial and femoral access for performing diagnostic cerebral angiography and interventions. Additional studies are needed to establish its efficacy and compare it with other access sites.

Background Recent advances in neuroendoscopic surgery have led to the minimally invasive treatment of brain abscesses using various endoscopy techniques. The endoscopic diving technique (EDT) involving the formation of fluid lenses to improve the visibility of the endoscope has been reported to be useful in the endoscopic endonasal approach (EEA) for pituitary and midline cranial base lesions. Here, we report a case of brain abscess treated endoscopically using EDT in cylinder surgery. Clinical presentation A 29-year-old man with 11q trisomy syndrome developed a fever and progressive right hemiparesis was observed. A diagnosis of a brain abscess was made based on neuroradiological imaging, and endoscopic irrigation and drainage with EDT via a transparent endoscopic sheath were performed, which provided a clear operative field and allowed satisfactory irrigation without bacterial contamination. The bacterium identified by PCR was Streptococcus intermedius, and antibiotic therapy was administered. Postoperatively, his symptoms gradually improved. Conclusion This is the first technical case report describing the clinical experience of EDT in brain abscess surgery. EDT may be a useful technique not only in EEA but also in cylinder surgery for brain abscesses.

BACKGROUNDIntraoperative magnetic resonance imaging (MRI) is useful for identifying residual tumors during surgery. It can improve the resection rate; however, complications related to prolonged operating time may be increased. We assessed the advantages and disadvantages of using low-field intraoperative MRI and compared them with non-use of iMRI during glioma surgery.METHODSThe study included 22 consecutive patients who underwent total tumor resection at Shinshu University Hospital between September 2017 and October 2020. Patients were divided into two groups (before and after introducing 0.4-T low-field open intraoperative MRI at the hospital). Patient demographics, gross total resection (GTR) rate, postoperative neurological deficits, need for reoperation, and operating time were compared between the groups.RESULTSNo significant differences were observed in patient demographics. While GTR of the tumor was achieved in 8/11 cases (73%) with intraoperative MRI, 2/11 cases (18%) of the control group achieved GTR (p=0.033). Seven patients had transient neurological deficits: 3 in the intraoperative MRI group and 4 in the control group, without significant differences between groups. There was no unintended reoperation in the intraoperative MRI group, except for one case in the control group. Mean operating time (465.8 vs. 483.6 minutes for the intraoperative MRI and control groups, respectively) did not differ.CONCLUSIONSLow-field intraoperative MRI improves the GTR rate and reduces unintentional reoperation incidence compared to the conventional technique. Our findings showed no operating time prolongation in the MRI group despite intraoperative imaging, which considered that intraoperative MRI helped reduce decision-making time and procedural hesitation during surgery.

A conchal non-pneumatized sphenoid sinus tends to be considered as unfavorable for transsphenoidal surgery because of procedural difficulties. Especially in acromegalic patients, the proportion of the conchal type of sphenoid sinus is potentially high compared with that of other patients who have a pituitary tumor. This report investigates the characteristics and surgery of the conchal type of sphenoid sinus in acromegaly along with the internal bone properties.A 70-year-old man with acromegaly underwent endoscopic endonasal transsphenoidal surgery. Intraoperatively, the anterior wall of the non-pneumatized sphenoid was cortical, however, the cancellous bone was very soft, included fatty tissue, and was easily removed by suction. The sellar lesion could be reached without any problems, and finally, total tumor resection was achieved.Based on this surgical case, the conchal sphenoid sinus of acromegaly is not always homogeneous solid bone but may contain soft fatty tissue. Therefore, although the sphenoidal characteristics may have an impact on the surgical procedures, precise assessment pre- and intraoperatively can make transsphenoidal surgery with conchal sphenoid sinus feasible.

Background The benefits of the right transradial approach for anterior circulation lesions using a 6F Simmonds guiding sheath have been reported. However, this technique can be anatomically challenging in the type I aortic arch. Furthermore, to the best of our knowledge, no studies have reported on neurointervention using a Simmonds guiding sheath and the left transradial approach. We devised a novel technique using the contralateral subclavian artery as an “anchor” to reform the Simmonds curve, named the subclavian artery anchoring technique (SCAT). The purpose of the present study was to evaluate the feasibility, safety, and usefulness of neurointervention with the SCAT for patients with a type I aortic arch treated with the right transradial approach and patients treated with the left transradial approach. Methods Ten consecutive patients treated from June 2018 to January 2019 were included in the present study. We retrospectively analyzed: 1) the success rate for reforming the Simmonds curve using the SCAT; 2) the success rate for introducing the 6F Simmonds guiding sheath into the target common carotid artery; 3) the success rate for completing the procedure; 4) periprocedural complications; and 5) vascular access site complications. Results In all 10 patients, the Simmonds curve was reformed, and a 6F Simmonds guiding sheath was introduced into the target common carotid artery. The procedure was successfully achieved for all 10 patients without periprocedural or vascular access site complications. Conclusions The results of the present study have shown that this technique is a feasible, safe, and useful method for patients with type I aortic arch treated with a right transradial approach or a left transradial approach. SCAT makes up for a deficiency in the transradial approach with a 6F Simmonds guiding sheath.

Several surgical procedures can be applied for syrinx associated with Chiari type 1 malformation; however, it remains controversial as to which approach is the most effective. Here, we evaluated the indications and limitations of foramen magnum decompression (FMD) with or without dural plasty. Forty patients with Chiari type 1 malformation were surgically treated and followed up for > 12 months. Thirty-two patients (80.0%) underwent FMD with removal of only the outer dura mater layer, while eight patients underwent FMD with dural plasty. We evaluated surgery-related complications and preoperative radiological findings affecting syrinx shrinkage rates. Post-surgery, the mean syrinx shrinkage rates were 0.32 ± 0.44 in the outer layer-removal group and 0.72 ± 0.27 in the dural plasty group (P = 0.012). Surgery-related complications were less frequent, but reoperation was more frequent, in the outer layer-removal group. The extent of tonsillar descent significantly affected syrinx shrinkage in FMD with outer layer removal (P = 0.042). The outcomes of both approaches in patients with tonsillar descent

Highlights • Motor threshold can be variable during surgery in TES-MEP. • The motor threshold in TES-MEP was influenced by intraoperative environmental changes. • The threshold change was greater on the affected side than on the unaffected side., Objective Motor threshold usually varies in the intraoperative motor evoked potential (MEP) by transcranial evoked stimulation (TES). This study investigated the degree of change in the motor threshold before and after surgery in TES-MEP monitoring with threshold criterion. This study aimed to evaluate the threshold change and discuss the factors influencing the motor threshold. Methods We retrospectively analyzed TES-MEP monitoring during supratentorial surgery with frontotemporal craniotomy in 72 patients without pre- and postoperative motor weakness. We analyzed the percentage changes between the affected and the unaffected sides, correlating the changes on the two sides. Results The percentage change on the affected and the unaffected side was 4.4 ± 15.1% and 0.4 ± 6.5%, respectively. The percentage change on the affected side was significantly larger than that on the unaffected side. A significantly positive correlation between the percentage change on the affected and the unaffected sides was detected. Conclusion The threshold for the TES-MEP varied significantly more than that on the unaffected side. Significance It is important to understand the characteristics of threshold variation for the evaluation of TES-MEP.

We present the case of a 74-year-old woman complaining of blurred vision in the left eye who was found to have a unilateral, continuous lesion of the optic nerve and nerve sheath accompanied by an intracranial mass next to the cavernous sinus and meninges. Surgical decompression of the left optic nerve in the optic canal and partial resection of the mass followed by prednisolone administration were successful. Immunohistochemical analysis disclosed abundant infiltration of IgG4-positive plasma cells at >10 cells/high power field. These findings indicated a new pattern of compressive optic neuropathy with confirmed IgG4 histopathological findings. Such an extensive lesion may produce visual disturbance.

Vestibular migraine (VM) commonly causes episodic vertigo/dizziness; however, its clinical features are unknown. Based on the evidence that central sensitization is related to VM pathogenesis, we hypothesized that cutaneous allodynia is frequently associated with patients with VM compared with patients without VM. This study aims to (1) elucidate the clinical features of patients with VM and (2) evaluate whether patients with VM were more frequently associated with cutaneous allodynia than patients without VM. This cross-sectional study enrolled consecutive patients with migraine aged 18–65 years. The comprehensive interview form included diagnostic questions regarding migraine and VM, demographic characteristics, migraine-specific variables, migraine-associated symptoms, and cutaneous allodynia. A total of 245 consecutive patients with migraine (mean age = 39.5 years, 81.2% women) were enrolled; 65 (26.5%) patients with VM were assigned to the VM group, 74 (30.2%) with migraine with vestibular symptoms not meeting the VM criteria (MwVS) were assigned to the MwVS group, and 106 (43.3%) patients with episodic migraine without vestibular symptoms (EM) were assigned to the EM group, respectively. Pairwise comparisons demonstrated no significant differences between the VM and MwVS groups, except for severe disability in the VM group. Compared with EM group, VM group had significant aura, severe disability, depression, tinnitus, sleep disorders, and widespread multimodal cutaneous allodynia. VM and MwVS may be on the same spectrum of disorders. The VM group had significantly associated widespread multimodal cutaneous allodynia compared with the EM group, indicating that thalamic sensitization plays a key role in VM pathogenesis. Widespread allodynia may be a useful diagnostic aid for VM.

The prognosis for spinal artery aneurysms associated with spinal cord arteriovenous malformations (AVMs) is poor because of the high rupture rate of aneurysms. However, endovascular treatment remains technically difficult because the catheter system must be constructed via the small-caliber anterior spinal artery (ASA) or posterior spinal artery (PSA), which feeds functionally eloquent spinal cord. A 2.6F Carnelian HF-S microcatheter (Tokai Medical Products, Aichi, Japan) has been specifically designed to assist a 1.6F Carnelian MARVEL S microcatheter (Tokai Medical Products) as a small-profile 'platform catheter' close to the target lesion. Here we present a prenidal ASA aneurysm treated using a 2.6F Carnelian HF-S microcatheter as an intraspinal canal platform catheter and review related literature.A 50-year-old man presented with a subarachnoid haemorrhage due to cervical spinal cord AVM. Diagnostic vertebral angiography revealed the AVM supplied by the PSA originated from the right C2 segmental artery and ASA arising from the right V4 segment. Superselective angiography for each feeder was achieved through a 2.6F Carnelian HF-S microcatheter, and a prenidal ASA aneurysm was diagnosed, which was clinically consistent with haemorrhagic origin. A 1.6F Carnelian MARVEL S microcatheter was cannulated into the aneurysm through the 2.6F Carnelian HF-S microcatheter positioned at the ASA. The aneurysm coiling was successfully performed without system instability or periprocedural complications.Only a few cases have described endovascular treatment for spinal artery aneurysms. To date, no reports have been published regarding the use of an intraspinal canal platform catheter to treat spinal artery aneurysms. A 2.6F Carnelian HF-S microcatheter served as a useful intraspinal canal platform catheter for coil embolization of the ASA aneurysm. This system can provide excellent accessibility and controllability for endovascular treatment of spinal artery lesions.

BACKGROUND Intraoperative flash stimulation visual evoked potential (VEP) monitoring has been used for endoscopic endonasal approach (EEA). Recently, off-response VEP, which is recorded when the light stimulus is turned off, was introduced to monitor visual function intraoperatively. OBJECTIVE To evaluate off-response VEP monitoring in comparison with the conventional flash stimulation VEP monitoring for EEA. METHODS From March 2015 to March 2020, 70 EEA surgeries with intraoperative VEP monitoring (140 eyes) were performed. Light stimuli were delivered by a pair of goggle electrodes. Recording electrodes were placed on the scalp over the occipital region. The warning signal was prompted by a reduction of the peak-to-peak amplitude of the VEP by more than 50% compared to the initial amplitude. Visual function was assessed pre- and postoperatively. Results of flash and off-response VEP monitoring were compared. RESULTS VEP was recorded in 134 eyes. Warning signal occurred in 23 eyes (transient in 17 eyes and permanent in 6 eyes). Two eyes showed permanent VEP attenuation for flash VEP monitoring, in which one patient had postoperative visual function deterioration. Four eyes showed permanent VEP attenuation for off-response VEP monitoring, where 2 patients had postoperative visual function deterioration. Sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 98.9%, 50%, and 100%, respectively, for flash stimulation VEP, and 100%, 97.8%, 50%, and 100%, respectively, for off-response VEP. CONCLUSION VEP monitoring was useful to monitor visual function in EEA surgery. Off-response VEP monitoring was not inferior to conventional flash stimulation VEP monitoring.

Acromegaly is an acquired disorder usually caused by growth hormone-secreting pituitary adenoma, resolution of which requires correction of the excess hormone production. Recently, intraoperative magnetic resonance imaging (iMRI) was reported to be useful during the endoscopic endonasal approach (EEA) for pituitary adenoma. The present study was performed to quantitatively assess the role of iMRI in improving surgical outcomes in EEA for acromegaly.Twenty surgeries for acromegaly in EEA performed at Shinshu University Hospital between April 2016 and March 2020 were reviewed retrospectively. The inclusion criteria were cases without severe cavernous sinus tumor invasion (Knosp grade 0 - 3) or history of prior pituitary surgery. Fifteen consecutive patients were enrolled in this study. Clinical characteristics and postoperative clinical outcomes were compared between patients with and without use of iMRI during EEA for acromegaly.Conventional navigation-guided surgery was performed in nine patients, and six underwent iMRI-guided EEA for acromegaly. Gross total resection (GTR) was obtained in the six (100%) patients in the iMRI group, and in four (44.4%) patients in the conventional group without iMRI. Postoperative clinical outcomes, including hormonal remission rate and surgical complications, were comparable between the two groups.Although iMRI significantly increased the GTR rate, we found no direct evidence of increased hormonal remission rate by use of iMRI. It is important to confirm complete tumor resection carefully with not only iMRI findings, but also with intraoperative high-definition endoscopic direct visualization to increase the hormonal remission rate of acromegaly.

Background: The demographic and clinical characteristics of vestibular migraine (VM) based on the International Classification of Headache Disorders (ICHD)-III beta are not well documented, and the underlying pathophysiology remains largely unknown. Based on evidence that central sensitization is involved in VM pathogenesis, we hypothesized that cutaneous allodynia (CA), which is a clinical manifestation of central sensitization, and interictal widespread pressure hyperalgesia (IWPH), which may be an accelerator for central sensitization, are more frequently associated with VM patients compared with non-VM patients. The aim of this study was as follows: 1) to assess differences in demographic and clinical characteristics among VM patients, patients with migraine with vestibular symptoms not meeting VM criteria (MwVS), and patients with migraine without vestibular symptoms (MwoVS); and 2) to evaluate whether VM patients were more frequently associated with CA/IWPH compared with the other two groups.Methods: This cross-sectional study enrolled consecutive migraine patients, aged 18–65. The comprehensive interview form included diagnostic questions of migraine and VM, demographic characteristics, migraine-specific variables, migraine-associated symptoms, and CA. IWPH occurrence was investigated using a manual tender point survey and clinical parameters were compared.Results: A total of 245 episodic migraineurs (mean age = 39.5 ± 11.3 years, 81.2% women) were enrolled. Based on ICHD-III beta criteria, 65 (26.5%), 74 (30.2%), and 106 (43.3%) patients were assigned to the VM group, MwVS group, or MwoVS group, respectively. Pairwise comparisons demonstrated no significant differences between the VM and MwVS groups, except for higher occurrence of headache disability in the VM group. Compared with the MwoVS group, the VM group was significantly associated with aura, severe disability, depression, tinnitus, sleep disorders, multimodal CA, and IWPH.Conclusions: There were no significant differences in clinical features between VM and MwVS groups, except for disability, which was possibly caused by criteria selection bias. VM and MwVS may be on the same disease process spectrum. Widespread multimodal CA, including clinical manifestations of thalamic sensitization, was significantly associated with VM patients compared with MwoVS patients, which indicates that thalamic sensitization may play a key role VM pathogenesis. Furthermore, IWPH may enhance susceptibility to thalamic sensitization.

Background A next-generation networked operating room, Smart Cyber Operating Theater (SCOT), has been developed in cooperation with medical engineers that integrates standalone medical devices, including intraoperative magnetic resonance imaging (MRI) using the OPeLiNK communication interface. Here, we report the application of this newly developed advanced type of operating theater for the endoscopic endonasal approach (EEA), along with an evaluation of our initial experiences. Methods The study population consisted of 18 patients with parasellar tumor. All patients underwent surgery via the EEA in SCOT. During all procedures, various types of intraoperative information, including electrophysiologic monitoring, anatomic orientation with navigation system, intraoperative MRI, and endoscopic images of the operative field, were collected and stored by OPeLiNK. Furthermore, the intraoperative information was shared with the surgical strategy desk, where a senior neurosurgeon can direct and manage the surgical procedure in real-time. Results We successfully completed the surgical procedures in SCOT in all cases. Using OPeLiNK, operators in SCOT were able to share various data, such as images obtained intraoperatively and surgical instrument position from navigation systems, as well as images of the surgical field, with senior neurosurgeons at the surgical strategy desk in all cases. Surgically relevant information from these sources was transmitted through an application and displayed to all surgical staff. The necessary nuances were reflected in the surgical procedures. Conclusions SCOT, which is considered an innovative operation system in neurosurgery, enables both quality and safety in the EEA. Furthermore, the use of SCOT may also contribute to the education of young neurosurgeons.

An unfavorable vertebral artery (VA) anatomy occasionally inhibits a successful VA cannulation due to flow stagnation after catheterization. To preserve antegrade VA flow, we developed bilateral transradial catheter systems, referred to as the role-sharing technique, for coil embolization of basilar artery (BA) aneurysms associated with an unfavorable VA anatomy. This study aimed to evaluate the feasibility and safety of coil embolization using the role-sharing technique for BA aneurysms. We retrospectively analyzed an institutional database of consecutive patients with BA aneurysm who underwent coil embolization using the role-sharing technique between July 2019 and January 2020. The study included seven consecutive patients. Bilateral transradial VA cannulation was performed using 3.2F catheters (TACTICS; Technocrat Corporation, Aichi, Japan) via 4F guiding sheaths placed in the subclavian artery. The following catheter systems were used: the triaxial system (4F guiding sheath/TACTICS/coil or stent delivery microcatheter) that has a specialized role in embolization and the biaxial system (4F guiding sheath/TACTICS) that has a specialized role in contrast injection during embolization procedure. The procedural success and procedure-related or vascular access site complications were assessed. All patients underwent a successful embolization procedure using the bilateral transradial catheter systems and none of them presented with flow stagnation, system instability, or other complications. The role-sharing technique was shown to be a feasible and safe method for coil embolization of BA aneurysms associated with an unfavorable VA anatomy. This method may increase the success rate of transradial coil embolization for BA aneurysms.

Background Stimulating electrodes for lower extremity motor-evoked potential (LE-MEP) monitoring with transcortical stimulation are usually placed on the medial side of motor cortex convexity, which is not lower extremity but lumbar motor area. Lumbar MEP may be elicited with lower stimulation intensity than LE-MEP through this location, and it is useful to monitor lower extremity motor function intraoperatively. Methods Intraoperative lumbar and LE-MEP monitoring with transcortical stimulation during surgery of 12 patients with lesions involving the motor cortex from January 2012 to February 2019 at Shinshu University Hospital were reviewed retrospectively. Stimulations were delivered by a train of 5 pulses of anodal constant current stimulation. Stimulating electrode position was determined by motor cortex mapping. Recording needle electrodes were placed on bilateral lumbar muscles and contralateral leg muscles. The threshold-level stimulation method was used for MEP monitoring. The thresholds, monitoring result, and postoperative motor function of lumbar and lower extremities were compared. Results The mean baseline thresholds were 19.9 ± 8.9 mA for lumbar MEP and 26.5 ± 11.5 mA for LE-MEP (P = 0.02). Patterns of intraoperative monitoring changes were the same between lumbar and LE-MEP monitoring. Conclusions Lumbar MEP was stimulated with lower stimulation intensity than the LE-MEP with the same intraoperative pattern of waveform changes in 12 patients. Lumbar MEP monitoring may be useful for preserving the corticospinal tract of lower extremities intraoperatively.

Background Spontaneous cerebrospinal fluid (CSF) rhinorrhea associated with untreated prolactinomas is rare, which is in contrast to medical treatment-induced CSF rhinorrhea. Previous studies have suggested that cessation of drug administration should be the first line of treatment for prolactinoma with medically induced CSF rhinorrhea. On the other hand, there is no standard treatment strategy for prolactinoma with the development of spontaneous CSF rhinorrhea, because of its complicated pathology. Here, we report a case of giant invasive macroprolactinoma with spontaneous CSF rhinorrhea, and discuss the treatment strategy for this complicated condition with a review of the relevant literature. Case Description A previously healthy 39-year-old man presented with 1-year history of intermittent clear fluid nasal discharge with headache and vomiting. Magnetic resonance imaging showed a large parasellar mass with destruction of the skull base. This tumor was diagnosed as prolactinoma with hypopituitarism based on the results of hormone examinations. Tumor resection with skull base reconstruction in the endoscopic endonasal approach was performed because CSF rhinorrhea was aggravated by bromocriptine loading test and administration of dopamine agonist. Life-threatening bacterial meningitis occurred after surgery, which was cured with antibiotics along with resolution the CSF rhinorrhea. Conclusions Careful consideration is necessary before applying standard first-line protocols with dopamine agonist administration in patients with prolactinoma, especially in cases with spontaneous CSF rhinorrhea. An appropriate treatment strategy should be planned according to the individual case, including factors such age, sex, pituitary function, tumor mass size, prolactin concentration, and condition of CSF leakage.

Background Trans-cell approach for the Neuroform Atlas stent (Stryker Neurovascular, Fremont, CA) is occasionally unsuccessful as a microcatheter can become stuck in the struts. This study aimed to evaluate the passability and impassability of 0.0165-inch microcatheters through the Neuroform Atlas stent using a simplified benchtop model. Methods The distal struts of the target cell, referred to as the concave or convex crown, were found to interfere with microcatheter advancement during the trans-cell approach. The procedure was performed across each crown using the 1.7-Fr SL-10 and 1.6-Fr Headway Duo microcatheters (MicroVention-Terumo, Aliso Viejo, CA), and it was repeated 20 times. We evaluated the procedural success rate, passability of each microcatheter using the maximum moving distance of the target crown in successful procedures, and device behaviors. Results The procedural success rate across the concave crown was significantly higher than that across the convex crown in both microcatheters. The maximum moving distance of the concave crown was significantly shorter in the Headway Duo microcatheter than in the SL-10 microcatheter. All procedures across the convex crown were not successful because the sharp end of the crown fell into the interspace inside the microcatheter tip, which is referred to as the crown jackpot phenomenon. The trapped microcatheter was never released from the crown unless it was pulled back proximally. Conclusions Target crowns and microcatheters affected the use of the trans-cell approach through the Neuroform Atlas stent. The passability was excellent in a lower profile 0.0165-inch microcatheter. Moreover, neurointerventionalists must be knowledgeable of the crown jackpot phenomenon, which might cause fatal stent migration.

Background Primary dedifferentiated liposarcoma of the orbit is a rare condition. Case Description A 41-year-old man presented with a history of right ophthalmalgia with eye movement and exophthalmos that had developed 2 months earlier. Neuroimages revealed a right orbital mass located above the superior rectus muscle. Tumor resection through the right frontal craniotomy was performed. Histopathologic findings showed the dedifferentiated liposarcoma. Conclusions Primary orbital dedifferentiated liposarcomas remain challenging for their diagnosis and standard treatment. Clinicians should keep in mind the possibility of liposarcoma with orbital tumors.

Background Hemodynamic factors, especially wall shear stress (WSS), are generally thought to play an important role in intracranial aneurysm (IA) formation. IAs frequently occur at bifurcation apices, where the vessels are exposed to the impact of WSS. Objective To elucidate the relationship between bifurcation geometry and WSS for IA formation. Methods Twenty-one bifurcation models varying in branch angles and branch diameters were made with 3-dimensional computer-aided design software. In all models, the value of maximum WSS (WSSMAX), the area of high WSS (AREA), and the magnitude of wall shear force over AREA ($| {{{\vec{F}}_w}} |$) were investigated by the steady-flow simulation of computational fluid dynamics. Results On the basis of statistical analysis, WSSMAX tended to be high when the bifurcation angle and/or branch diameter was small. AREA and $| {{{\vec{F}}_w}} |$ significantly increase as the bifurcation and/or the branch angle became larger. Conclusion The magnitude of WSS strongly correlated with bifurcation geometry. In addition to high WSS, AREA and $| {{{\vec{F}}_w}} |$ were thought to affect IA formation. Observed bifurcation geometry may predict IA formation. Large branch angles and small branch may increase the risk of IA formation.

PURPOSE The removal of brain tumors requires not only imaging information such as MRI and navigation systems, but also a variety of other information such as neurological function and biological information. To integrate this information, a novel operating room, “Smart Cyber Operating Theater (SCOT)”, which connects the medical devices in the operating room via a network has developed. In this SCOT, the intraoperative information is time-synchronized, recorded, and stored by the middleware “OPeLiNK”. Clinical experience of brain tumor surgery using OPeLiNK in our institute is reported. Methods Brain tumor surgeries performed at SCOT, which had been started since July 2018, was enrolled. In all surgeries intraoperative information was integrated by OPeLiNK. Surgical procedure was discussed between main surgeon and supervising surgeon in the Strategy Desk through OPeLiNK intraoperatively, if necessary. Clinical and radiological data from patients who underwent resection at SCOT were analyzed retrospectively. Results Sixty patients were involved. Histopathological diagnosis was glioma in 29 patients, pituitary adenoma in 29 patients, acoustic tumor in 1 patient and intravascular lymphoma in 1 patient. Intraoperative discussion with Strategy Desk through OPeLiNK was useful for not only surgeons but also for medical staff in operation room. Advice for extent of resection and craniotomy from Strategy Desk was conducted by OPeLiNK using conversation and drawing. Intraoperative comment was useful for postoperative review. OPeLiNK, which display multiple intraoperative information, was also used at postoperative conference. Conclusion We have reported clinical experience with OPeLiNK for brain tumor surgery in our institute. OPeLiNK was useful for not only sharing intraoperative information with doctors outside the operation room but also postoperative review and education for young doctors.

Pediatric reversible cerebral vasoconstriction syndrome (RCVS) and spontaneous cervical internal carotid artery (ICA) vasospasm are rare conditions; the former is commonly associated with a favorable prognosis. A healthy 13-year-old girl presented with thunderclap headache, followed by left hemiparesis, during a curling match. Six days after onset, left hemiparesis worsened to hemiplegia. Magnetic resonance imaging showed progressive cerebral infarction caused by severe right middle cerebral artery and cervical ICA stenosis. She became comatose because of impending uncal herniation. Emergent surgical decompression was performed. Then, 59 days after onset, her multiple stenoses improved, which was consistent with RCVS concomitant with spontaneous cervical ICA vasospasm. This is the first case of RCVS that concurrently developed spontaneous cervical ICA vasospasm. The patient developed life-threatening stroke due to the hemodynamic impairment of the affected intracranial and cervical arteries. Spontaneous extracranial supra-aortic artery vasospasm can be a poor prognostic predictor of RCVS.

Purpose Endovascular treatment for subclavian artery (SA) occlusive disease is well established; however, a potential risk remains for posterior circulation embolism, which can be life threatening. To reduce the risk of vertebral artery (VA) embolism, we have devised a transradial dual-balloon protection system referred to as the balloon switching technique. Herein, we describe a patient with left SA stenosis who successfully underwent SA stenting using the balloon switching technique. Case presentation A 79-year-old woman with left arm claudication was diagnosed with left subclavian steal syndrome due to severe stenosis of the proximal left SA. Endovascular revascularization using the balloon switching technique was employed. To obtain VA embolic protection during device advancement through the SA lesion, an 8F balloon-guiding catheter was inflated in the left SA at the level of the VA takeoff using the left transradial sheathless approach. A balloon-expandable stent was inflated in the SA lesion, followed by deflation of the balloon-guiding catheter. The stagnant left VA flow was flushed away toward the distal left SA. Following reinflation of the balloon-guiding catheter, the stent delivery system was deflated and removed. Floating debris in the SA proximal to the balloon-guiding catheter was adequately aspirated, followed by deflation of the balloon-guiding catheter. Left SA angiography showed successful revascularization, and postprocedural neuroimaging showed no evidence of ischemic stroke. Conclusions The balloon switching technique reduces the risk of VA embolism during left SA stenting via the transradial access. This method is a useful therapeutic option for patients with left SA occlusive disease.