Clinical Characteristics and Longterm Outcomes of Spinal Pilocytic Astrocytomas: A Multicenter Retrospective Study by the Neurospinal Society of Japan

Jun Muto,Hidetoshi Murata,Seiji Shigekawa,Takafumi Mitsuhara,Daisuke Umebayashi,Ryo Kanematsu,Masahiro Joko,Tatsushi Inoue,Tomoo Inoue,Toshiki Endo,Yuichi Hirose 대한척추신경외과학회 2023 Neurospine Vol.20 No.3

Objective: The characteristics, imaging features, long-term surgical outcomes, and recurrence rates of primary spinal pilocytic astrocytomas (PAs) have not been clarified owing to their rarity and limited reports. Thus, this study aimed to analyze the clinical presentation, radiological features, pathological findings, and long-term outcomes of spinal PAs. Methods: Eighteen patients with spinal PAs who were surgically treated between 2009 and 2020 at 58 institutions were included in this retrospective multicenter study. Patient data, including demographics, radiographic features, treatment modalities, and long-term outcomes, were evaluated. Results: Among the 18 consecutive patients identified, 11 were women and 7 were men; the mean age at presentation was 31 years (3–73 years). Most PAs were located eccentrically, were solid or heterogeneous in appearance (cystic and solid), and had unclear margins. Gross total resection (GTR), subtotal resection (STR), partial resection (PR), and biopsy were performed in 28%, 33%, 33%, and 5% of cases, respectively. During a follow-up period of 65 ± 49 months, 4 patients developed a recurrence; however, the recurrence-free survival did not differ significantly between the GTR and non-GTR (STR, PR, and biopsy) groups. Conclusion: Primary spinal PAs are rare and present as eccentric and intermixed cystic and solid intramedullary cervical tumors. The imaging features of spinal PAs are nonspecific, and a definitive diagnosis requires pathological support. Surgical resection with prevention of neurological deterioration can serve as the first-line treatment; however, the resection rate does not affect recurrence-free survival. Investigation of relevant molecular biomarkers is required to elucidate the regrowth risk and prognostic factors.

Transoral Robotic-Assisted Neurosurgery for Skull Base and Upper Spine Lesions

Jun Muto,Ichiro Tateya,Hirofumi Nakatomi,Ichiro Uyama,Yuichi Hirose 대한척추신경외과학회 2024 Neurospine Vol.21 No.1

Objective: The application of the da Vinci Surgical System in neurosurgery is limited due to technical difficulties requiring precise maneuvers and small instruments. This study details the advantages and disadvantages of robotics in neurosurgery and the reachable range of the transoral approach to lesions of the skull base and upper cervical spine. Methods: In a cadaver study, the da Vinci Xi robot, lacking haptic feedback, was utilized for sagittal and coronal approaches on 5 heads, facilitating dura suturing in 3, with a 30°-angled drill for bone removal. Results: Perfect exposure of all the nasopharyngeal sites, clivus, sellar, and choana, including the bilateral eustachian tubes, was achieved without any external incisions using this palatal split approach of transoral robotic surgery. The time required to perform a single stitch, knot, and complete single suture in robotic suturing of deep-seated were significantly less compared to manual suturing via the endonasal approach. Conclusion: This is the first report to show the feasibility of suturing the dural defect in deepseated lesions transorally and revealed that the limit of reach in the coronal plane via a transoral approach with incision of the soft palate is the foramen ovale. This preclinical investigation also showed that the transoral robotic approach is feasible for lesions extending from the sellar to the C2 in the sagittal plane. Refinement of robotic instruments for specific anatomic sites and future neurosurgical studies are needed to further demonstrate the feasibility and effectiveness of this system in treating benign and malignant skull base lesions.

日本行政文化에 관한 硏究

全鐘燮,武藤博己 漢陽大學校 行政問題硏究所 1993 行政問題論集 Vol.12 No.-

環境問題의 解決과 政策刷新 : 日本의 事例分析

全鐘燮,武藤博己 漢陽大學校 行政問題硏究所 1993 行政問題論集 Vol.12 No.-

The Impact of Adjuvant Radiotherapy on Clinical Performance Status in Patients With Grade II Spinal Cord Astrocytoma – A Nationwide Analysis by the Neurospinal Society of Japan

Ryo Kanematsu,Masaki Mizuno,Tomoo Inoue,Toshiyuki Takahashi,Toshiki Endo,Seiji Shigekawa,Jun Muto,Daisuke Umebayashi,Takafumi Mitsuhara,Kazutoshi Hida,Junya Hanakita 대한척추신경외과학회 2023 Neurospine Vol.20 No.3

Objective: The impact of adjuvant radiotherapy on overall survival (OS) and progressionfree survival (PFS) of patients with grade II spinal cord astrocytomas remains controversial. Additionally, the relationship between progression and clinical deterioration after radiotherapy has not been well investigated. Methods: This study included 53 patients with grade II intramedullary spinal cord astrocytomas treated by either subtotal, partial resection or open biopsy. Their clinical performance status was assessed immediately before operation and 1, 6, 12, 24, and 60 months after surgery by Karnofsky Performance Scale (KPS). Patients with and without adjuvant radiotherapy were compared. Results: The groups with and without radiation comprised 23 and 30 patients with a mean age of 50.3 ± 22.6 years (range, 2–88 years). The mean overall disease progression rate was 47.1% during a mean follow-up period of 48.4 ± 39.8 months (range, 2.5–144.5 months). In the radiation group, 11 patients (47.8%) presented with progressive disease, whereas 14 patients (46.7%) presented with progressive disease in the group without radiation. There were no significant differences in OS or PFS among patients with or without adjuvant radiotherapy. KPS in both groups, especially radiation group, gradually decreased after operation and deteriorated before the confirmation of disease progression. Conclusion: Adjuvant radiotherapy did not show effectiveness regarding PFS or OS in patients with grade II spinal cord astrocytoma according to classical classification based on pathohistological findings.

Advancements and Challenges in Robot-Assisted Bone Processing in Neurosurgical Procedures

Yoshihiro Kitahama,Hiroo Shizuka,Yuto Nakano,Yukoh Ohara,Jun Muto,Shuntaro Tsuchida,Daisuke Motoyama,Hideaki Miyake,Katsuhiko Sakai 대한척추신경외과학회 2024 Neurospine Vol.21 No.1

Objective: Practical applications of nerve decompression using neurosurgical robots remain unexplored. Our ongoing research and development initiatives, utilizing industrial robots, aim to establish a secure and efficient neurosurgical robotic system. The principal objective of this study was to automate bone grinding, which is a pivotal component of neurosurgical procedures. Methods: To achieve this goal, we integrated an endoscope system into a manipulator and conducted precision bone machining using a neurosurgical drill, recording the grinding resistance values across 3 axes. Our study encompassed 2 core tasks: linear grinding, such as laminectomy, and cylindrical grinding, such as foraminotomy, with each task yielding unique measurement data. Results: In linear grinding, we observed a proportional increase in grinding resistance values in the machining direction with acceleration. This observation suggests that 3-axis resistance measurements are a valuable tool for gauging and predicting deep cortical penetration. However, problems occurred in cylindrical grinding, and a significant error of 10% was detected. The analysis revealed that multiple factors, including the tool tip efficiency, machining speed, teaching methods, and deflection in the robot arm and jig joints, contributed to this error. Conclusion: We successfully measured the resistance exerted on the tool tip during bone machining with a robotic arm across 3 axes. The resistance ranged from 3 to 8 Nm, with the measurement conducted at a processing speed approximately twice that of manual surgery performed by a surgeon. During the simulation of foraminotomy under endoscopic grinding conditions, we encountered a -10% error margin.