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The objective of this retrospective study is to more fully understand the optimal strategy to manage spinal arteriovenous (AV) shunts. This study included a cohort of 35 patients with a diagnosis of spinal AV shunts who were treated over the past 10 years at a single institute. Angiographic diagnosis of intramedullary AV malformations (IM-AVM), perimedullary AV fistulas (PM-AVF), dural AV fistulas (D-AVF), or epidural AV fistulas (ED-AVF) was carefully made, and the microsurgical or endovascular strategy for them was determined at the interdisciplinary meeting consisting of neurospinal surgeons and endovascular specialists. Endovascular surgery was first considered whenever safely possible. Microscopic direct surgery using intraoperative image guidance was considered for cases in which endovascular access was challenging or not safely possible. Combined treatment was another option. The clinical condition was assessed using the modified Rankin scale (mRS). Seventeen of 35 cases were treated with microscopic direct surgery, 13 cases with endovascular surgery, and the remaining five cases with the combination. Complete angiographic obliteration was achieved in 30 of 35 cases (85.7%). Although residual AV shunts was recognized in 3 cases of IM-AVM, 1 case of PM-AVF and 1 case of ED-AVF, no angiographic recurrence was present with an average postoperative follow-up period of 44 months. The average mRS before surgery was 2.37 and significantly improved to 1.94 at the most recent follow-up. Interdisciplinary collaboration between neurospinal surgeons and endovascular specialists should be standard to achieve safe and successful outcomes in treating such rare and difficult spinal disorders.

OBJECTIVESpinal arteriovenous shunts are rare vascular lesions and are classified into 4 types (types I–IV). Due to rapid advances in neuroimaging, spinal epidural AVFs (edAVFs), which are similar to type I spinal dural AVFs (dAVFs), have recently been increasingly reported. These 2 entities have several important differences that influence the treatment strategy selected. The purposes of the present study were to compare angiographic and clinical differences between edAVFs and dAVFs and to provide treatment strategies for edAVFs based on a multicenter cohort.METHODSA total of 280 consecutive patients with thoracic and lumbosacral spinal dural arteriovenous fistulas (dAVFs) and edAVFs with intradural venous drainage were collected from 19 centers. After angiographic and clinical comparisons, the treatment failure rate by procedure, risk factors for treatment failure, and neurological outcomes were statistically analyzed in edAVF cases.RESULTSFinal diagnoses after an angiographic review included 199 dAVFs and 81 edAVFs. At individual centers, 29 patients (36%) with edAVFs were misdiagnosed with dAVFs. Spinal edAVFs were commonly fed by multiple feeding arteries (54%) shunted into a single or multiple intradural vein(s) (91% and 9%) through a dilated epidural venous plexus. Preoperative modified Rankin Scale (mRS) and Aminoff-Logue gait and micturition grades were worse in patients with edAVFs than in those with dAVFs. Among the microsurgical (n = 42), endovascular (n = 36), and combined (n = 3) treatment groups of edAVFs, the treatment failure rate was significantly higher in the index endovascular treatment group (7.5%, 31%, and 0%, respectively). Endovascular treatment was found to be associated with significantly higher odds of initial treatment failure (OR 5.72, 95% CI 1.45–22.6). In edAVFs, the independent risk factor for treatment failure after microsurgery was the number of intradural draining veins (OR 17.9, 95% CI 1.56–207), while that for treatment failure after the endovascular treatment was the number of feeders (OR 4.11, 95% CI 1.23–13.8). Postoperatively, mRS score and Aminoff-Logue gait and micturition grades significantly improved in edAVFs with a median follow-up of 31 months.CONCLUSIONSSpinal epidural AVFs with intradural venous drainage are a distinct entity and may be classified as type V spinal vascular malformations. Based on the largest multicenter cohort, this study showed that primary microsurgery was superior to endovascular treatment for initial treatment success in patients with spinal edAVFs.

The objective of this study was to more fully understand the optimal neurosurgical strategy for spinal benign meningiomas from a medium to long-term perspective. This retrospective study included a cohort of 35 patients with a diagnosis of spinal meningioma who were first operated at our institute over the past 10 years and followed-up for at least 2 years after surgery. The inclusion criterion for the study was the pathological diagnosis finally verified as benign meningioma of World Health Organization (WHO) grade 1. The average follow-up duration after surgery was 61.0 months. The location of the spinal meningioma was classified into ventral or dorsal type based on the operative video record and the preoperative MR images. The extent of resection of the spinal meningioma was carefully determined based on the Simpson grade. The average neurological condition was significantly improved at the final follow-up. Simpson grade I or II resection was achieved in 31 of 35 cases (88.6%). No Simpson grade I or II cases showed local recurrence during follow-up. Tumor recurrence was noted in 2 of 4 cases of Simpson grade IV resection. One case has been followed-up without any re-operation because of no neurological deterioration, and the other case underwent stereotactic radiosurgery. This study suggested that meticulous Simpson grade II resection of spinal benign meningiomas of WHO grade 1 may be good enough from a medium to long-term follow-up perspective, though longer follow-up is absolutely necessary.

Background: Boron neutron capture therapy (BNCT) has been adapted to high-grade gliomas (HG); however, some gliomas are refractory to BNCT using boronophenylalanine (BPA). In this study, the feasibility of BNCT targeting the 18 kDa translocator protein (TSPO) expressed in glioblastoma and surrounding environmental cells was investigated. Methods: Three rat glioma cell lines, an F98 rat glioma bearing brain tumor model, DPA-BSTPG which is a boron-10 compound targeting TSPO, BPA, and sodium borocaptate (BSH) were used. TSPO expression was evaluated in the F98 rat glioma model. Boron uptake was assessed in three rat glioma cell lines and in the F98 rat glioma model. In vitro and in vivo neutron irradiation experiments were performed. Results: DPA-BSTPG was efficiently taken up in vitro. The brain tumor has 16-fold higher TSPO expressions than its brain tissue. The compound biological effectiveness value of DPA-BSTPG was 8.43 to F98 rat glioma cells. The boron concentration in the tumor using DPA-BSTPG convection-enhanced delivery (CED) administration was approximately twice as high as using BPA intravenous administration. BNCT using DPA-BSTPG has significant efficacy over the untreated group. BNCT using a combination of BPA and DPA-BSTPG gained significantly longer survival times than using BPA alone. Conclusion: DPA-BSTPG in combination with BPA may provide the multi-targeted neutron capture therapy against HG.

Background We previously reported a phase II trial of accelerator-based boron neutron capture therapy (BNCT) for patients with malignant glioma, which showed a long median overall survival of 18.9 months. However, median progression-free survival was 0.9 months. In this trial, bevacizumab was permitted to use after progressive disease. The reason of discrepance between a short progression-free survival and a long overall survival was speculated that progression disease included pseudoprogression. But, efficacy of add-on bevacizumab on overall survival was not ignored. Methods The present study was approved by the Osaka Medical and Pharmaceutical University certificated review board and registered for Japan Registry of Clinical Trial (jRCTs051220019). Twenty-one patients who had malignant glioma refractory to bevacizumab treatment were planned to enroll in the study. The primary endpoint was a response rate of boronophenylalanine positron emission tomography. The secondary endpoints were a response rate of magnetic resonance image and safety. Conclusion Patients have been enrolled from June 2022. The efficacy of BNCT for malignant glioma could be elucidated by PET evaluation of tumor viability after BNCT.

Boron neutron capture therapy (BNCT) is a particle therapy that can target tumors at the cellular level. BNCT has been developed for the treatment of malignant gliomas with widely infiltrated tumors, but as the indication for BNCT was expanded to include the whole body, the focus shifted to borophalan-10B (BPA), which is based on the essential amino acid phenylalanine, as a candidate agent. We started BNCT for brain tumors in 2002 with a protocol combining two compounds (BPA, BSH) that had been clinically used, but later, with the development of an accelerator-based system, we conducted a clinical study of a single agent of BPA with a modified administration protocol in a nuclear reactor. In this report, we analyze the clinical studies of BNCT for recurrent malignant glioma using the reactor as a neutron source, and discuss the possibility of BNCT using multiple drugs in combination. The median survival with BSH+BPA was 11.0 months (n=29) overall, and the MST with BPA alone was 11.1 months (n=24), with similar results for BPA alone. The blood boron levels at the time of irradiation were 46.3 and 27.3 μg/ml, respectively, which were higher with the addition of BSH. The irradiation doses converted to X-rays (Gy) equivalent were calculated to be 69 and 76 Gy-Eq for the maximum tumor, 37 and 40 Gy-Eq for the minimum, and 10.9 and 10.5 Gy-Eq for the normal brain, respectively. The biological effectiveness ratios for tumor and normal tissue from neutron capture reactions with boron compounds and tissue boron concentrations were factored into these calculations, and since BPA and BSH have different target systems (BPA in the infiltration zone and BSH in the contrast zone, respectively), we believe that their combined use may improve therapeutic efficacy and attenuate adverse events.

Ependymomas encompass multiple, clinically relevant tumor types based on localization, genetic alterations, and epigenetic and transcriptomic profiles. Tumors belonging to the methylation class of spinal ependymoma (SP-EPN) represent the most common intramedullary neoplasms in children and adults. However, molecular data of SP-EPN are scarce, and clear treatment recommendations are lacking. The only known recurrent genetic events in SP-EPN are loss of chromosome 22q and NF2 mutations. Yet, it remains unclear whether SP-EPN with germline or sporadic NF2 mutations or with NF2 wild type status differ clinically or molecularly. To provide a comprehensive molecular profile of SP-EPN, we integrated epigenetic, genomic, transcriptomic, and histological analyses of up to 237 cases. Clustering of methylation data revealed two distinct molecular SP-EPN subtypes. The distribution of NF2 mutated cases differed significantly across these subtypes (p

Determining the optimal surgical method for cervical ossification of the posterior longitudinal ligament (OPLL) is challenging. The surgical indication should be made based on not only radiological findings, but also the patient’s age, preoperative neurological findings, social background, activities of daily life, and the presence or absence of comorbid diseases. Anterior resection for OPLL with or without wide corpectomy and fusion, posterior decompression with or without relatively long fusion, or anterior and posterior combined surgery may be considered. When evaluating the clinical condition of patients with cervical OPLL before surgery, various radiological parameters should be carefully considered, including the number of spinal segments involved, the cervical alignment or tilt angle, the relationship between OPLL and the C2–7 line (termed the “K-line”), the occupying ratio of OPLL, and the involvement of dural ossification. The objective of this article is to review the radiological parameters in current use for deciding upon the optimal surgical strategy and for predicting surgical outcomes, focusing on cervical OPLL.

Surgery for neoplastic or vascular lesions at the craniovertebral junction remains one of the major challenges for neurosurgeons, because of issues such as the complex functional anatomy and vascular structures. We present three cases in which the high cervical lateral approach was used to safely remove the cystic retro-odontoid pseudotumor, not associated with rheumatoid arthritis, severely compressing the spinal cord. The mean age of patients was 74.7 years (range, 73-77 years). Neurological condition was assessed based on the neurosurgical cervical spine scale. A high cervical lateral approach was applied to remove the pseudotumor safely. Mean duration of follow-up after surgery was 21.3 months (range, 18-24 months). Mean recovery rate was 77.8%. All patients showed acceptable or satisfactory functional recovery, although one patient (Case 2) developed mild paralysis of the facial and spinal accessory nerve on the surgical approach side, but that completely recovered within about 1 month after surgery. Postoperative assessment at the recent follow-up suggested no significant aggravation of neck movement. This technical note suggests that the high cervical lateral approach can be considered as a surgical option for cystic retro-odontoid pseudotumor, not associated with rheumatoid arthritis, severely compressing the spinal cord. Safe management of the vertebral artery is one of the key considerations.

The surgical strategy for severely localized ossification of the posterior longitudinal ligament (OPLL) of the cervical spine is still not straightforward. We describe the surgical technique of extended anterior cervical discectomy and fusion (ACDF) with partial resection of OPLL followed by posterior cervical segmental decompression and fusion (PCDF). This study investigated five patients with severely localized OPLL with an occupying ratio more than 60%. Extended ACDF comprising a modified technique with a trans-unco-discal approach and partial oblique corpectomy was first attempted to achieve neural decompression of the spinal cord and nerve roots at the most prominent level of the OPLL. The OPLL was partially resected to reduce the axial occupying ratio or ensure that the OPLL did not exceed the imaginary line between the midpoint between C2 and C7 on sagittal images. PCDF was then performed to achieve satisfactory decompression of neural elements and cervical stability. One patient underwent one-stage surgery and the remaining four patients underwent two-stage surgery. No patients received spinal cerebrospinal fluid (CSF) drainage and demonstrated CSF leakage after surgery. All patients showed acceptable or satisfactory functional recovery. No instrumentation-related complications were encountered. Radiological analysis demonstrated that all except one patient (OPLL associated with ankylosing spinal hyperostosis) revealed improvements in local angle, C2-7 angle and cervical tilt angle. This anterior and posterior segmental decompression and fusion for severely localized OPLL of the cervical spine remains technically demanding in some parts, but can offer satisfactory decompression of neural elements and stabilization of the cervical spine when applied appropriately.

Background: The primary radiological goal of surgery for adult spinal deformity (ASD) is the restoration of lumbar lordosis (LL). Radiological parameters were analyzed to determine the surgical indications for ASD using posterior side-loading spinal instrumentation system. Materials and Methods: This retrospective study included 31 patients of ASD who underwent posterior instrumented fusion surgery. Imaging parameters included spinal tilt angle (STA), LL, and thoracic kyphosis (TK). The ideal LL was estimated based on the normal value. Results: Of 16 patients with sagittal imbalance, 10 patients demonstrated sagittal balance postoperatively. All six patients with frontal imbalance showed frontal balance postoperatively. STA improvement well correlated with change of LL. On univariate analysis, preoperative TK was significantly associated with preoperative sagittal imbalance and postoperative lack of LL with postoperative sagittal imbalance. Conclusions: The surgical concept of ASD focusing on correction of LL was demonstrated. Although the surgery of ASD is still challenging, posterior instrumented fusion surgery using posterior side-loading system may be well applied for mild or moderate ASD without hyper-TK. The posterior side-loading system is practical and can be one of the surgical choices.

[No Abstract Available]

Study design Clinical case series. Objective To present a surgical technique and results of posterior direct reduction of lateral atlantoaxial joints for rigid pediatric atlantoaxial subluxation (AAS) using a fulcrum lever technique. Summary of background data The surgical treatment of pediatric rigid AAS is still technically challenging. Several factors contribute to the surgical difficulty, such as small vertebrae, incomplete bone formation, dysplasia, the difficulty of reduction and external fixation are considered as a surgical daunting challenge. Herein, the surgical technique of posterior direct reduction of lateral atlantoaxial joints for rigid pediatric AAS using a fulcrum lever technique is presented. Methods This retrospective study included 10 pediatric patients with rigid AAS who underwent posterior direct reduction of bilateral C1/2 facet joints via a fulcrum lever technique. The indication for surgery was the presence of neurological symptoms and spinal cord atrophy with an intramedullary high signal at the C1 level on T2-weighted magnetic resonance (MR) images. The surgical procedure consisted of three steps: (1) opening and distraction of the C1/2 facet joints and placement of tricortical bone as a spacer and fulcrum; (2) placement of C1 and C2 screws; and finally, (3) compression between the C1 posterior arch and C2 lamina and constructing C1/2 fusion. All patients underwent the neurological and radiological evaluations before and after surgery. Results Eight of 10 patients demonstrated genetic disorders, either Down syndrome or chondrodysplasia punctate. Besides, all cases documented congenital anomaly of the odontoid process. Bilateral C1 lateral mass screws were successfully placed in all cases. No evidence of postoperative neurovascular complications. Radiological evaluation showed the corrections and bony fusions of C1/2 facet joint in all cases. Conclusion The fulcrum lever technique for rigid pediatric AAS can be one of the effective surgical solutions to this challenging pediatric spinal disorder. Level of evidence 4.

OBJECTIVEThe purpose of the present study was to compare the treatment success rates of primary neurosurgical and endovascular treatments in patients with spinal dural arteriovenous fistulas (dAVFs).METHODSData from 199 consecutive patients with thoracic and lumbosacral spinal dAVFs were collected from 18 centers. Angiographic and clinical findings, the rate of initial treatment failure or recurrence by procedures, risk factors for treatment failure, complications, and neurological outcomes were statistically analyzed.RESULTSSpinal dAVFs were frequently detected in the thoracic region (81%), fed by a single feeder (86%), and shunted into an intradural vein via the dura mater. The fistulous connection between the feeder(s) and intradural vein was located at a single spinal level in 195 patients (98%) and at 2 independent levels in 4 patients (2%). Among the neurosurgical (n = 145), and endovascular (n = 50) treatment groups of single dAVFs (n = 195), the rate of initial treatment failure or recurrence was significantly higher in the index endovascular treatment group (0.68% and 36%). A multivariate analysis identified endovascular treatment as an independent risk factor with significantly higher odds of initial treatment failure or recurrence (OR 69; 95% CI 8.7–546). The rate of complications did not significantly differ between the two treatment groups (4.1% for neurosurgical vs 4.0% for endovascular treatment). With a median follow-up of 26 months, improvements of ≥ 1 point in the modified Rankin Scale (mRS) score and Aminoff-Logue gait and Aminoff-Logue micturition grades were observed in 111 (56%), 121 (61%), and 79 (40%) patients, respectively. Independent risk factors for lack of improvement in the Aminoff-Logue gait grades were multiple treatments due to initial treatment failure or recurrence (OR 3.1) and symptom duration (OR 1.02).CONCLUSIONSBased on data obtained from the largest and most recently assessed multicenter cohort, the present study shows that primary neurosurgery is superior to endovascular treatment for the complete obliteration of spinal dAVFs by a single procedure.

Made available in DSpace on 2021-06-25T11:47:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-12-01 Ege Univ, Dept Neurosurg, 1416 Sok 7 Kahramanlar, Izmir, Turkey Liaquat Natl Hosp & Med Coll, Karachi, Pakistan Humanitas Univ, Dept Neurosurg, Milan, Italy Univ Mumbai, LTM Med Coll, Dept Neurosurg, Mumbai, Maharashtra, India Capital Med Univ, Xuanwu Hosp, Dept Neurosurg, Beijing, Peoples R China Rush Univ, Dept Neurosurg, Med Ctr, Chicago, IL 60612 USA Korea Univ, Ansan Hosp, Dept Neurosurg, Med Ctr, Ansan, South Korea Osaka Med Coll, Dept Neurosurg, Takatsuki, Osaka, Japan Tsukazaki Hosp, Dept Neurosurg, Himeji, Hyogo, Japan Neurochirurg CMCO Cote dOpale St Martin, Boulogne, France President Continental Assoc African Neurosurg Soc, Nairobi, Kenya Burdenko Inst, Dept Neurosurg, Moscow, Russia Sao Paulo State Univ, Dept Neurosurg, Sao Paulo, Brazil El Bosque Univ, Dept Neurosurg, Bogota, Colombia ABC Med Ctr, Dept Neurosurg, Mexico City, DF, Mexico Airlangga Univ, Dept Neurosurg, Surabaya, Indonesia Kovai Med Ctr, Dept Neurosurg, Coimbatore, Tamil Nadu, India Univ Philippines, St Lukes Med Ctr, Bonifacio Global City, Philippines Hosp Lusiadas, Dept Neurosurg, Porto, Portugal Univ Saarland, Dept Neurosurg, Homburg, Germany Univ Belgrade, Clin Ctr Serbia, Dept Neurosurg, Belgrade, Serbia Leiden Univ, Dept Neurosurg, Med Ctr, Leiden, Netherlands Kathmandu Univ, Nepal Med Coll & Teaching Hosp, Dept Neurosurg, Kathmandu, Nepal Cairo Univ, Dept Neurosurg, Cairo, Egypt Usmanu Danfodiyo Univ Teaching Hosp, Sokoto, Nigeria Univ Bamenda, Fac Hlth Sci, Neurosurg Div, Bambili, Cameroon Bangabandhu Shiek Mujib Med Univ, Dept Neurosurg, Dhka, Bangladesh Med Univ Varna, Multiprofile Hosp St Anna Varna, Varna, Bulgaria Hirslanden Klin St Anna Lucerne, Dept Neurosurg, Luzern, Switzerland Mem Hosp, Istanbul, Turkey Med Univ Varna, Varna, Bulgaria Sao Paulo State Univ, Dept Neurosurg, Sao Paulo, Brazil

Objective Health-related quality of life (HRQOL) after surgery for spinal intramedullary benign encapsulated tumors remains unclear. A single-institute, 3-year, prospective study was conducted to examine HRQOL after microscopic total removal of spinal intramedullary ependymomas using a safe and precise strategy. Methods A cohort of 20 patients with a possible diagnosis of spinal intramedullary benign ependymomas was recruited. Patients who underwent microscopic total removal of the tumor and for whom the pathologic diagnosis was verified as World Health Organization grade II benign ependymoma were included. Sixteen patients (average age, 48.7 years) were eligible for study analysis. Careful assessment was performed for all patients before and 6–12 months after surgery. The 36-Item Short Form Health Survey was used to assess HRQOL, with the surveyor recording answers as reported by the individual patient. Results Average total HRQOL score was 431.1 before surgery and was maintained at 434.2 at 6–12 months postoperatively. Patients with mild functional symptoms tended to demonstrate a higher total HRQOL score preoperatively compared with patients with moderate to severe functional symptoms. A strong correlation was noted between postoperative functional conditions and preservation of HRQOL. Conclusions This is the first study focusing on HRQOL after microscopic total removal of spinal intramedullary ependymomas. This study suggested that radical surgery using a safe and precise strategy appears justifiable and that preservation of neurologic function after surgery may lead to maintenance of postoperative HRQOL.

Degenerative cervical myelopathy (DCM) eventually affects not only activities of daily living but also quality of life. DCM is usually a gradually progressive, sometimes irreversible, disease of the cervical spinal cord, although there is always a risk of acute deterioration caused by minor trauma. There is still not enough evidence regarding the prognosis of mild DCM without surgical treatment, and conservative treatment seems a reasonable option, although patients need to be followed closely because some do deteriorate over time. Surgeons need to understand, however, the importance of decision making in the surgical management of mild DCM.

BACKGROUND Ependymomas are currently classified into 9 subgroups by DNA methylation profiles. Although spinal cord ependymoma (SP-EPN) is distinct from other tumors, diversity within SP-EPN is still unclear. Here, we used transcriptomic and epigenomic profiles to investigate the diversity among Japanese SP-EPN cases. MATERIALS AND METHODS We analyzed 57 SP-EPN patients (32 males and 25 females, aged from 18 to 78 years, median: 52), including two cases of neurofibromatosis type 2, five cases of grade 3 (WHO grade). We obtained transcriptome (RNA-seq) and DNA methylation (Infinium Methylation EPIC array) data from fresh frozen specimens of SP-EPN resected at the University of Tokyo Hospital and our collaborative groups. RESULTS Three cases had a previous intracranial ependymoma operation. Hierarchical clustering of the DNA methylation data showed that these three cases of intracranial origin as a different cluster from spinal origin. The 45 grade 2 spinal ependymoma showed a relatively homogenous methylation pattern. However, the methylation status of HOX gene cluster regions is compatible with the segment of origin, which reflects the cells of origins are derived after the determination of segment identity. RNA sequencing of 57 cases revealed two subgroups within grade 2. Gene ontology analysis of differentially expressed genes suggested the difference in metabolic state such as rRNA translation and mitochondrial respiration between the two expression subgroups. CONCLUSION Epigenetic analysis indicated the accurate body segment origin of SP-EPN. We observed that metabolic states could divide grade 2 spinal cord ependymoma into 2 subgroups and will present the relationship to clinicopathological information.

Background Intraoperative image guidance using near-infrared indocyanine green videoangiography (ICG-VA) has been used to provide real-time angiographic images during vascular or brain tumor surgery, and it is also being used for spine surgery. Objective To further investigate the benefits and limitations of ICG-VA image-guided surgery for spinal intramedullary tumors through retrospective study. Methods ICG-VA was used in 48 cases that were treated surgically over the past 5 yr. The pathological diagnoses of the tumors included astrocytic tumor, ependymal tumor, cavernous malformation, and hemangioblastoma. Results Localization of normal spinal arteries and veins on the dorsal surface of the spinal cord helped the surgeons determine the length or point of myelotomy. Well-demarcated tumor stain was recognized in limited cases of anaplastic or highly vascularized tumors, whereas the location of cavernous malformation was recognized as an avascular area on the dorsal surface of the spinal cord. Feeding arteries and tumor stain were well differentiated from draining veins in dorsal hemangioblastomas, but not in intramedullary deep-seated or ventral tumors. The preservation of small perforating branches of the anterior spinal artery after successful resection of the tumor could be well visualized. Conclusion ICG-VA can provide real-time information about vascular flow dynamics during the surgery of spinal intramedullary tumors, and it may help surgeons localize the normal circulation of the spinal cord, as well as the feeding arteries and draining veins, especially in highly vascular tumors. However, the benefits of intraoperative ICG-VA might be limited for intramedullary deep-seated or ventral tumors.

The objective of this retrospective case analysis was to evaluate the surgical impact on neurological functional recovery in cases of solitary spinal nerve sheath tumors (NSTs) originating around the epiconus, conus medullaris, or cauda equina and not associated with neurofibromatosis. This 10-year surgical study included 30 cases of spinal NSTs originating around the spine level of T12-L1 (epiconus-to-conus medullaris: Epi-CM group), and 15 cases of spinal NSTs originating below the spine level of L2 (cauda equina: CE group). A minimally invasive posterior unilateral approach was applied in 22 of 30 subjects in the Epi-CM group and in 14 of 15 subjects in the CE group. Total removal of the tumor was achieved in all cases except in two cases of subpial growth and foraminal extension in the Epi-CM group at the initial surgery. Functional assessment revealed satisfactory or acceptable neurological recovery in both groups. Twelve of 30 patients (40%) in the Epi-CM group demonstrated significant motor weakness of the ipsilateral leg, predominantly manifested as drop foot before surgery, and only 4 of 12 patients demonstrated complete recovery. Ten of 30 patients (33%) in the Epi-CM group demonstrated a significant disturbance of urination before surgery, and only 6 of 10 demonstrated complete recovery. No patients in the CE group demonstrated unsatisfactory recovery of leg motor weakness or urinary disturbance. The present study suggests that surgeons should be aware that spinal NSTs originating around the epiconus or conus medullaris may result in delayed or inadequate functional recovery, even after successful surgical resection of tumors.

This multicenter prospective study investigated cage subsidence in anterior cervical discectomy and fusion (ACDF) using titanium-coated polyetheretherketone (PEEK) stand-alone cages. This study recruited patients who underwent 1- or 2-level ACDF using titanium-coated PEEK stand-alone cages for cervical disc disease. Patients with acute trauma or past cervical spine operations were excluded. Sixty-two cages in 42 patients were eligible for analysis. Minimum follow-up was 6 months after ACDF. Significant cage subsidence was recognized in 11 of 62 cages (17.7%). Cage subsidence was predominantly moderate (14.5%), with severe subsidence found in only 2 cages (3.2%). The slowest occurrence of cage subsidence was 6 months after surgery, in 4 of 11 cages. Frequency of cage subsidence did not differ significantly between patients 65 and ≥65 years old. Patients with and without cage subsidence both demonstrated significant improvement of neurological function. Cage subsidence resulted in aggravation of local angle, but finally did not affect C2-7 angle or cervical tilt angle. Severe cage subsidence was found in only 3.2% of patients within 6 months after ACDF. Cage subsidence aggravated local angle, but finally did not affect C2-7 angle or cervical tilt angle. One- or 2-level ACDF using titanium-coated PEEK stand-alone cages appears safe and justified, even in elderly patients.

Introduction We classified Chiari malformation type I (CM-I) according to the mechanism of ptosis of the brain stem and cerebellum, based on a morphometric study of the posterior cranial fossa (PCF) and craniovertebral junction (CVJ). Surgery was performed to manage the mechanism of the hindbrain ptosis. Materials and Methods We calculated the volume of the PCF (VPCF) and the area surrounding the foramen magnum (VSFM) and measured the axial length of the enchondral parts of the occipital bone (occipital bone size) and the hindbrain. According to these measures, we classified CM-I into type A (normal VPCF, normal VSFM, and normal occipital bone size), type B (normal VPCF, small VSFM, and small occipital bone size), and type C (small VPCF, small VSFM, and small occipital bone size). Foramen magnum decompression (FMD) (280 cases) was performed on CM-I types A and B. Expansive suboccipital cranioplasty (ESCP) was performed on CM-I type C. Posterior craniocervical fixation (CCF) was performed in cases with CVJ instability. Lysis of the adhesion and/or sectioning of the filum terminale were performed on cases with tethered cord syndrome. Results Both ESCP and FMD had a high rate of improvement of neurological symptoms (87%) and recovery rate. There was only small number of complications. CCF had a high rate of improvement of neurological symptoms (88%) and joint stabilization. Conclusion In the management of Chiari malformation, appropriate surgical methods that address ptosis of the hindbrain should be chosen. Each surgical approach resulted in a good improvement of neurological symptoms.

Objective Although syringomyelia associated with extensive spinal adhesive arachnoiditis (SAA) can be a progressive disease that has potentially devastating clinical consequences, its surgical resolution has remained poorly defined. The aim of the present study was to verify the safety and efficacy of syringoperitoneal shunting for syringomyelia associated with extensive SAA. Methods The present retrospective study included 15 patients who had undergone syringoperitoneal shunting with a programmable shunt valve for the diagnosis of syringomyelia associated with extensive SAA from October 2012 to June 2018. The shunt pressure was appropriately adjusted according to the postoperative sequential clinical condition and change in syringomyelia evaluated using magnetic resonance imaging. The average postoperative follow-up duration was 32.7 months. Results No surgery-related complications such as shunt dysfunction or infection occurred during the follow-up period, except for 2 patients with minor issues with the shunt tube. The average shunt pressure at the last follow-up examination was 4.5 cm H2O. The findings from the clinical assessment suggested that the average grade on the sensory pain scale was 2.9 before surgery and had improved significantly to 2.5 at the most recent follow-up examination. Radiological analysis suggested that improvement of syringomyelia was noted in 14 of the 15 patients (93.3%), with no cases of radiological aggravation. No recurrence of syringomyelia developed during the follow-up period in the present study. Conclusion Syringoperitoneal shunting with a programmable shunt valve was safe and effective for clinical control of syringomyelia associated with extensive SAA. Long-term follow-up is mandatory to monitor for shunt dysfunction and mechanical trouble.

Background Os odontoideum is a smooth, independent ossicle separated from a hypoplastic odontoid process located cranially in the expected position of the odontoid tip. The pathogenesis of os odontoideum remains controversial, and several etiological theories have been suggested for congenital, developmental, and traumatic origins. Case Description We have reported symptomatic familial cases of dystopic os odontoideum in 2 elderly sisters who denied any traumatic history of the head and neck. Both patients were treated surgically, with successful outcomes achieved. Conclusions When examining the etiology of os odontoideum, checking for the existence of a traumatic history is important. However, a more important matter is to consider morphological segmentation abnormalities of the proatlas. Segmentation abnormalities of the proatlas could be closely connected to the development of familial os odontoideum.

A simulation code based on the discrete element method (DEM) and computational fluid dynamics (CFD) coupling model was developed to simulate the behavior of radioactive cesium in waste incinerators. The waste lump was represented by particles in the simulation. The energy equation for a mixed gas, diffusion equation for each gas component, as well as the energy, drying, pyrolysis, and combustion equations for each particle were solved in the simulation by adding a combustion model to the standard DEM–CFD coupling model. The particle size of the waste changed as drying, pyrolysis, and combustion progressed. At the end of the combustion process, particle waste became ash, and the number of ash particles was enormous. To avoid an excessive computational load due to the high particle number, a similar assembly model was adopted to reduce the particle number in the calculation. There was a good agreement between the simulation and experimental results for the temperature at the outlet of the furnace and the flue gas composition.

BACKGROUND Ependymomas commonly occur in the fourth ventricle and the spinal cord. Gross total resection, age and WHO grade are known prognostic factors. Ependymomas are currently classified into 9 distinct subgroups by DNA methylation profile analysis. Spinal cord ependymoma is distinct from other subgroups. To investigate heterogeneity within spinal cord ependymoma, we examined DNA methylation profiles. MATERIALS AND METHODS We used Infinium MethylationEPIC array (illumina) to obtain DNA methylation data from frozen specimens of spinal ependymoma resected at the University of Tokyo, Osaka City University, and Tokyo Metropolitan Neurological Hospital. Japan Pediatric Molecular Neuro-Oncology Group provided methylation data for 11 reported cases. Cluster analysis was performed using Cluster3.0. RESULTS We analyzed 34 patients, 21 male and 13 female, aged from 18 to 76 years (median 50.5 years), including 2 cases with neurofibromatosis type 2. WHO grade was grade_3 in 2 cases and grade_2 in others. Clustering of the DNA methylation data showed that WHO grade_3 cases tended to be classified into a subgroup distinct from other cases. CONCLUSION This is the largest DNA methylation profiling study on spinal cord ependymoma to date. The study may suggest a new subgroup correlated with higher WHO grade.

Background Dissection of the internal carotid artery (ICA) can cause occlusion or severe stenosis and is known to be one of the major causes of ischemic stroke in the young. Endovascular treatment is one of the useful options for carotid dissections, but passing the guidewire through the occlusion (lesion-cross) and confirmation of the true lumen are sometimes difficult. Case presentation A 40-year-old right-handed man complaining of dysarthria and gait disturbance consulted our hospital. Magnetic resonance imaging and angiography revealed right ICA dissection. Because of worsening symptoms with conservative treatment, we performed endovascular treatment. Prior to the lesion-cross, a microcatheter was navigated to the third segment of the internal maxillary artery and a balloon-guiding catheter was navigated to the proximal ICA. Under balloon occlusion of the ICA, superselective angiography via the ipsilateral maxillary artery and slow evacuation from the balloon-guiding catheter were performed. Thereafter, the course of the true lumen was clearly visualized, and we were able to navigate another microcatheter without difficulty. Subsequently, angioplasty and stent placement were successfully accomplished. Conclusion We presented a case of ICA dissection and demonstrated a novel technique for a safe lesion-cross for occlusive ICA dissection.

Background One of the most critical steps in surgery for spinal intramedullary ependymomas is the resection of small feeding arteries from the anterior spinal artery with anatomical preservation of the normal circulation of the ventral spinal cord. Objective To quantitatively analyze the microcirculation of the ventral spinal cord by near-infrared indocyanine green videoangiography (ICG-VA) after the spinal intramedullary ependymoma resection. Methods This retrospective study included 12 patients (7 male and 5 female; average age 55.2 years, range 36-79 years). Patients' neurological conditions were assessed based on the modified McCormick functional schema of grade 1 (neurologically normal) to 5 (severe deficit). Postoperative functional assessment was conducted at least 3 months after surgery. Quantitative analysis of vascular flow dynamics was carried out following spinal intramedullary ependymoma resection. Fluorescence intensities were measured and the indocyanine green (ICG) intensity-time curves were analyzed and compared with the functional outcomes after surgery. Results Microscopically total or subtotal resection of the intramedullary ependymoma was achieved in all cases. Average peak time on ICG-VA was significantly shorter in the postoperative functional grade 1 to 2 group than in the postoperative functional grade 3 to 5 group, but there was no significant difference in average peak intensity between the 2 groups. Postoperative functional grade and the peak time of ICG, but not peak intensity, appeared correlated. Conclusion To the best of our knowledge, this is the first report showing that quantitative analysis of ICG-VA may predict functional outcomes after spinal intramedullary ependymoma resection.

Although spinal instrumentation technique has undergone revolutionary progress over the past few decades, it may still carry significant surgery-related risks. The purpose of the present study was to assess the radiological accuracy of spinal screw instrumentation using a hybrid operating room (OR) and quantify the related radiation exposure. This retrospective study included 33 cases of complex spine fusion surgeries that were conducted using a hybrid OR with a flat panel detector (FPD) angiography system. Twelve cases (36.4%) were cervical, and 21 (63.6%) were thoracolumbar. The average number of spine fusion levels was 3 and 4.8, respectively, at the cervical and thoracolumbar spine levels. A FPD angiography system was used for intraoperative cone-beam computed tomography (CBCT) to obtain multi-slice spine images. All operations were conducted under optimized radiation shielding. Entrance surface doses (ESDs) and exposure times were recorded in all cases. A total of 313 screws were placed. Satisfactory screw insertion could be achieved in all cases with safe screw placement in 97.4% and acceptable placement in 2.6%. None of the cases showed any significant anatomical violation by the screws. The radiation exposure to the patients was absolutely consistent with the desired ESD value, and that to the surgeons, under the annual dose limit. These results suggest that the hybrid OR with a FPD angiography system is helpful to achieve safe and precise spinal fusion surgery, especially in complex cases.

OBJECT Although the usefulness of PET for brain lesions has been established, few reports have examined the use of PET for spinal intramedullary lesions. This study investigated the diagnostic utility of PET/CT for spinal intramedullary lesions. METHODS l-[methyl-11C]-methionine (MET)- or [18F]-fluorodeoxyglucose (FDG)-PET/CT was performed in 26 patients with spinal intramedullary lesions. The region of interest (ROI) within the spinal cord parenchyma was placed manually in the axial plane. Maximum pixel counts in the ROIs were normalized to the maximum standardized uptake value (SUVmax) using subject body weight. For FDG-PET the SUVmax was corrected for lean body mass (SULmax) to exclude any influence of the patient’s body shape. Each SUV was analyzed based on histopathological results after surgery. The diagnostic validity of the SUV was further compared with the tumor proliferation index using the MIB-1 monoclonal antibody (MIB-1 index). RESULTS A total of 16 patients underwent both FDG-PET and MET-PET, and the remaining 10 patients underwent either FDG-PET or MET-PET. Pathological diagnoses included high-grade malignancy such as glioblastoma multiforme, anaplastic astrocytoma, or anaplastic ependymoma in 5 patients; low-grade malignancy such as hemangioblastoma, diffuse astrocytoma, or ependymoma in 12 patients; and nonneoplastic lesion including cavernous malformation in 9 patients. Both FDG and MET accumulated significantly in high-grade malignancy, and the SULmax and SUVmax correlated with the tumor proliferation index. Therapeutic response after chemotherapy or radiation in high-grade malignancy was well monitored. However, a significant difference in SULmax and SUVmax for FDG-PET and MET-PET was not evident between low-grade malignancy and nonneoplastic lesions. CONCLUSIONS Spinal PET/CT using FDG or MET for spinal intramedullary lesions appears useful and practical, particularly for tumors with high-grade malignancy. Differentiation of tumors with low-grade malignancy from nonneoplastic lesions may still prove difficult. Further technological refinement, including the selection of radiotracer or analysis evaluation methods, is needed.

Spinal hamartoma is a very rare, benign spinal lesion, usually occurring in children with either spinal dysraphism or neurofibromatosis type 1. We report a case of thoracic spinal hamartoma in a 75-year-old male without associated lesions. This patient represents the oldest of 19 patients whose cases we found reported in detail and one of only nine reported cases without associated lesions. On magnetic resonance imaging, the current patient showed a well-defined exophytic appearance arising from the dorsal midline surface of the spinal cord. We discuss the radiological and pathological features of spinal hamartoma and review the literature, focusing on magnetic resonance imaging features for diagnosing spinal hamartoma.

Surgery for spinal intramedullary tumors remains one of the major challenges for neurosurgeons, due to their relative infrequency, unknown natural history, and surgical difficulty. We are sure that safe and precise resection of spinal intramedullary tumors, particularly encapsulated benign tumors, can result in acceptable or satisfactory postoperative outcomes. General surgical concepts and strategies, technical consideration, and functional outcomes after surgery are discussed with illustrative cases of spinal intramedullary benign tumors such as ependymoma, cavernous malformation, and hemangioblastoma. Selection of a posterior median sulcus, posterolateral sulcus, or direct transpial approach was determined based on the preoperative imaging diagnosis and careful inspection of the spinal cord surface. Tumor-cord interface was meticulously delineated in cases of benign encapsulated tumors. Our retrospective functional analysis of 24 consecutive cases of spinal intramedullary ependymoma followed for at least 6 months postoperatively demonstrated a mean grade on the modified McCormick functional schema of 1.8 before surgery, deteriorating significantly to 2.6 early after surgery (< 1 month after surgery), and finally returning to 1.7 in the late postoperative period (> 6 months after surgery). The risk of functional deterioration after surgery should be taken into serious consideration. Functional deterioration after surgery, including neuropathic pain even long after surgery, significantly affects patient quality of life. Better balance between tumor control and functional preservation can be achieved not only by the surgical technique or expertise, but also by intraoperative neurophysiological monitoring, vascular image guidance, and postoperative supportive care. Quality of life after surgery should inarguably be given top priority.

Background: Spinal meningioma with ventral attachment is a challenging pathology. Several technical modifications have been proposed to secure safe and precise resection of these tumors. Materials and Methods: This retrospective study focused on the precise and safe surgery of spinal meningiomas with strictly ventral attachment of cervical or thoracic spine. The surgical technique included a lateral oblique position for the patient, laminectomy with unilateral medial facetectomy on the tumor side, and spinal cord rotation with the dentate ligament. The neurological status of patients was assessed using the modified McCormick functional schema (mMFS) and sensory pain scale (SPS) before and at least 3 months after surgery. Patients were followed-up for a mean of 23.7 months. Tumor removal was graded using the Simpson grade for removal of meningiomas, and the extent of excision was confirmed using early postoperative magnetic resonance imaging. Results: Simpson grade 1 or 2 resections were achieved in all cases. No major surgery-related complications were encountered, postoperatively. The mean mMFS score before surgery was 3.1, improving significantly to 1.7 after surgery (P < 0.05). The mean SPS score before surgery was 2.4, improving significantly to 1.6 after surgery (P < 0.05). Conclusions: This surgical technique offers a posterolateral surgical corridor to the ventral canal of both cervical and thoracic spine. The present preliminary analysis suggests that functional outcomes were satisfactory with minimal surgery-related complications, although considerable surgical experience is needed to achieve a high level of surgical confidence.

Degenerative cervical myelopathy (DCM) eventually affects not only activities of daily living but also quality of life. DCM is usually a gradually progressive, sometimes irreversible, disease of the cervical spinal cord, although there is always a risk of acute deterioration caused by minor trauma. There is still not enough evidence regarding the prognosis of mild DCM without surgical treatment, and conservative treatment seems a reasonable option, although patients need to be followed closely because some do deteriorate over time. Surgeons need to understand, however, the importance of decision making in the surgical management of mild DCM.

Background Selection of the access myelotomy is a key issue in surgery for spinal intramedullary tumors. This study focused on surgical outcomes with the posterolateral sulcus (PLS) approach, equivalent to dorsal root entry zone myelotomy. Methods This retrospective study of the 10-year period from 2007 to 2016 included 90 cases of spinal intramedullary lesions (99 operations). A PLS approach was indicated for intramedullary lesions situated laterally in the spinal cord showing no contact with the spinal cord surface. Neurological conditions before and after surgery were carefully assessed objectively. Results A PLS approach was applied in 34 of the 99 operations (34.3%). Among 70 cases involving astrocytic tumor, ependymal tumor, cavernous malformation or hemangioblastoma, 23 cases (32.9%) were operated on using a PLS approach. Microscopically gross total or subtotal removal of the tumor was achieved in 18 of 23 cases (78.3%). These 18 cases demonstrated mild deterioration of motor function on the approach side early after surgery, but usually resolving within several months postoperatively. Average grade of the modified McCormick functional schema before surgery was maintained 6 months postoperatively. Average grade of the sensory pain scale before surgery was significantly improved by 6 months postoperatively. Segmental dysesthesia on the approach side unexpectedly remained in 2 of 18 cases (11.1%) even late after surgery. Conclusions These findings suggest that the PLS approach can provide direct access to tumors with minimal tissue damage, when applied appropriately after careful case selection.

This article is on the dimensional analysis and the classification of fluidization from the viewpoint of numerical analysis. At first, the governing equations used in the DEM (Discrete Element Method) and CFD (Computational Fluid Dynamics) coupling model was non-dimensionalized with the method of Hellums and Churchill (1964). From the resulting dimensionless equations, it was concluded that the five dimensionless numbers, i.e. Re: Reynolds number, Ar: Archimedes number, Ga: Galilei number, Fr: Froude number and i�²*: ratio of particle density divided by fluid density, can be derived and hydrodynamically dominant on the fluid behaviors. Further, these can illustrate the dimensionless numbers proposed in the previous studies. Secondary, a three-dimensional flow regime map of homogeneous, bubbling and turbulent fluidizations was proposed with these dimensionless numbers using the DEM-CFD simulations. Finally, the plane of the minimum bubbling fluidization velocity umb in the map can be proposed and expressed as,a��Rea��_mb=0.263I�^(*-0.553) a��Ara��^0.612. umb can be estimated using this equation for various conditions.

Background: Although spinal meningiomas respond favorably to surgical excision, their surgical management is impacted by several factors. This study utilized a surgery-based grading system to discuss the optimal surgical strategy. Methods: Twenty-three consecutive patients who underwent surgery for spinal meningiomas were included in this retrospective study. The patients’ neurological condition was assessed using the modified McCormick functional schema (mMFS) and sensory pain scale (SPS), and tumor removal was assessed using Simpson grade. Major factors contributing to surgical difficulty included; tumor size, extent/severity of cord compression, location of tumor attachment, spinal level, and anatomical relationships plus tumor extending in a dumbbell shape and local postoperative recurrence. Results: Fifteen cases were classified as ventral attachment (65.2%). There were two dumbbell-shaped tumors and three local recurrences at the primary site. Simpson grade 1 or 2 resections were performed in 18 of 20 cases (90%) with preoperative surgical grades 0 to 3. Simpson grade 4 resections were achieved in all three cases with preoperative surgical grades 4 to 5. Overall neurological assessment after surgery revealed the satisfactory or acceptable recovery on mMFS and SPS analysis. Conclusions: Lower preoperative grade yielded better results, while the higher the preoperative grade, the more likely tumor was insufficiently removed. A preoperative surgical grading system appeared to be helpful when considering the surgical strategy. Ventral meningiomas could be safely resected via the posterolateral or lateral approach using technical modifications. Recurrent tumors, especially with ventral attachment, were hard to resolve, and primary surgery appears to be important.