Prevention of Cerebrospinal Fluid Leakage in the Anterior Transpetrosal Approach.

Background: The anterior transpetrosal approach (ATPA) is effective for reaching petroclival lesions, and it allows for complications such as impaired venous return and neuropathy to be resolved. However, there is still room for improvement regarding cerebrospinal fluid (CSF) leakage. Here, we aim to focus on describing specific preoperative, intraoperative, and postoperative countermeasures for preventing CSF leakage when using the ATPA. Methods: Eleven patients treated using the ATPA, who were treated at our hospital from June 2019 to February 2023, were included in this descriptive study. Preoperatively, we performed a 3D simulation of the opened air cells. Then, we classified patterns of dural closure into three types based on intradural manipulation and whether it involved opened air cells or not. Intraoperatively, we performed a dural closure that included the use of more-watertight sutures (DuraGen®) and an endoscope. Furthermore, temporal bone air cell volume measurements were performed to confirm the correlation between the volume and factors related to CSF leakage. Results: No postoperative CSF leakage was observed in any patient. The temporal bone air cell volumes significantly corelated with the air cells of the petrous apex, the high-risk tract in the petrous apex, and postoperative fluid collection in mastoid air cells. Conclusions: We have described countermeasures for preventing CSF leakage when using the ATPA. Preoperative simulations and the use of multiple-layered dural reconstructions with endoscopes could be considered more reliable methods for preventing CSF leakage when using the ATPA.

Aneurysmal subarachnoid hemorrhage occurring during sleep: Clinical characteristics and risk factors.

BACKGROUND: Aneurysmal subarachnoid hemorrhage (aSAH) is known to be triggered by several specific human activities. Sleep, by contrast, has not been considered a triggering activity for aSAH, and clinical characteristics of patients who sustain aSAH during sleep have rarely been reported in the literature. METHODS: This is a retrospective analysis on the data acquired through a multicenter aSAH registry. Between January 2019 and December 2021, a total of 732 aSAH patients had been registered into our database. After excluding 109 patients whose activities at aSAH onset had been unidentifiable, the remaining 623 aSAH patients were dichotomized to 59 patients who sustained aSAH during sleep (Sleep group) and 564 patients who sustained aSAH during daytime activities (Awake group). Two-group comparison of demographic variables and multivariate logistic regression analysis were performed to clarify their clinical characteristics and identify potential risk factors. RESULTS: The Sleep group exhibited significantly higher frequencies of diabetes (15.5 % vs. 6.4 %, p = 0.01) and antiplatelet use (13.8 % vs. 4.6 %, p=0.004) than the Awake group. Furthermore, multivariate logistic regression analysis showed that diabetes (OR, 3.051; 95 % CI, 1.281-7.268; p = 0.012) and antiplatelet use (OR, 3.640; 95 % CI, 1.422-9.316; p = 0.007) were correlated with aSAH occurring during sleep. There were no significant inter-group differences in the patient outcomes evaluated at discharge. CONCLUSION: The current results indicate that risk factors may exist for aSAH occurring during sleep. Further investigations on how comorbidities such as diabetes, antiplatelet use and sleep apnea affect human hemodynamic and hemostatic parameters during sleep is warranted to better understand those relationships.

Clinical, histopathological and molecular risk factors for recurrence of pilocytic astrocytomas: brainstem/spinal location, nestin expression and gain of 7q and 19 are associated with early tumor recurrence.

Pilocytic astrocytomas (PAs) are benign tumors. However, clinically aggressive PAs despite benign histology have been reported, and histological and molecular risk factors for prognosis have not been elucidated. 38 PAs were studied for clinical, histological, and molecular factors, including tumor location, extent of resection, post-operative treatment, glioma-associated molecules (IDH1/2, ATRX, BRAF, FGFR1, PIK3CA, H3F3A, p53, VEGF, Nestin, PD-1/PD-L1), CDKN2A/B deletion, and chromosomal number aberrations, to see if there is any correlation with patient's progression-free survival (PFS). Brainstem/spinal location, extent of resection and post-operative treatment, and VEGF-A, Nestin and PD-L1 expression, copy number gain of chromosome 7q or 19, TP53 mutation were significantly associated with shorter PFS. None of the histological parameters was associated with PFS. Multivariate analyses demonstrated that high Nestin expression, gain of 7q or 19, and extent of removal were independently predictive for early tumor recurrence. The brainstem/spinal PAs appeared distinct from those in the other sites in terms of molecular characteristics. Clinically aggressive PAs despite benign histology exhibited high Nestin expression. Brainstem/spinal location, extent of resection and some molecular factors including Nestin expression and gains of 7q and 19, rather than histological parameters, may be associated with early tumor recurrence in PAs.

Tumor immune microenvironment is associated with the growth of intracranial germinomas.

INTRODUCTION: The role of immune checkpoint molecules and the tumor immune microenvironment in the development of intracranial germ cell tumors remains unclear. METHODS: We investigated the expression of programed cell death-1 (PD-1), programed cell death ligand-1 (PD-L1), and tumor-infiltrating lymphocytes (TILs) in 8 patients who had intracranial germinomas with sufficient tumor tissue by immunohistochemistry, to analyze the associations between their clinical courses and radiological features. The 8 patients were categorized based on the duration between symptom onset and pathological diagnosis into the long-term onset (LTO) group (> 1 year of symptoms) and the short-term onset (STO) group (< 1 year of symptoms). RESULTS: Three patients belonged to the LTO group and 5 patients to the STO group. Compared with STO tumors, LTO tumors were significantly associated with a lower ratio of PD-L1-positive tumor cells (p = 0.012), higher number of infiltrating CD3- and CD8-positive lymphocytes (p = 0.016, 0.003, respectively), and lower ratio of PD-1-positive cells per CD8-positive lymphocytes (p = 0.047). LTO germinomas were significantly smaller in size than STO tumors, not associated with hydrocephalus, and tended to be present in patients with older age at diagnosis and atypical tumor location. CONCLUSIONS: Our data suggest that the tumor immune microenvironment, including PD-1/PD-L1 signaling, is associated with the growth of intracranial germinomas.

A Case of Aggressive Recurrent Intracranial Subdural Hematoma Associated with Angiosarcoma Originating from the Skull.

BACKGROUND: Angiosarcoma often arises as a cutaneous disease in the scalp and the face; however, subdural hematoma (SDH) associated with angiosarcoma is extremely rare. CASE DESCRIPTION: A 72-year-old woman visited our hospital with gait disorder and progressive consciousness disturbance approximately 3 months after a minor head injury. Initially, on reviewing the results of imaging studies, she was diagnosed with traumatic chronic SDH. Despite repeated operations thereafter, including the embolization of the middle meningeal artery, her general condition progressively worsened, and computed tomography of head repeatedly showed the recurrence of SDH. Based on histopathologic and intraoperative findings, she was finally diagnosed with angiosarcoma originating from the skull. She died shortly thereafter because of aggressive recurrent intracranial SDH caused by leptomeningeal dissemination. CONCLUSIONS: In addition to cancers metastatic to the skull or dura mater, angiosarcoma should be included in the differential diagnosis for patients with repeated SDH and bone defect. An effective treatment for angiosarcoma with SDH that shows an unfavorable prognosis has not been established; however, an early diagnosis might be useful for a novel treatment.

Pros and cons of using ORBEYE™ for microneurosurgery.

OBJECTIVE: To evaluate the pros and cons of using a newly developed microscope, ORBEYE™, during microneurosurgery. PATIENTS AND METHODS: ORBEYE™ use in 14 microneurosurgical procedures was retrospectively assessed by nine neurosurgeons after the procedure. A questionnaire comprising 20 questions was designed and used for evaluation. RESULTS: Compared with the current gold standard, the binocular microscope, ease of setting up the equipment was scored the highest, whereas ease of conducting surgery in a position of an assistant was scored the lowest. Among characteristics of ORBEYE™ itself, the space-saving feature was scored the highest and was followed by the ability to perform procedures in a comfortable position. The only characteristic that was rated below average was ease of operation in a position of an assistant. Neurosurgeons with greater experience (more than five procedures using ORBEYE™) provided significantly higher scores (p = 0.0196) for characteristics of ORBEYE™ itself compared with neurosurgeon with fewer ORBEYE™ experience. CONCLUSIONS: The main benefits of the ORBEYETM are its compact size and freedom from focusing through the eye lens of a conventional binocular microscope. However, it appears to be disadvantageous for operating in a position of an assistant because the surgical field has a rotated view on the monitor from a position of an assistant. Nonetheless, because of certain advantages, we believe the ORBEYE™ could be of additional help to use of conventional binocular microscope at the moment and will facilitate microneurosurgery in the future.

Usefulness of Intraoperative Imaging in a Patient with a Ruptured Aneurysm of the M4 Segment of the Middle Cerebral Artery.

BACKGROUND: Treating cerebral aneurysms in the M4 segment of the middle cerebral artery (MCA) is challenging because they are small and are buried in the brain parenchyma. CASE DESCRIPTION: A right-handed Asian woman in her 80s was referred to our hospital with a chief complaint of altered level of consciousness. On admission, her consciousness level on the Glasgow Coma Scale was 7 (E1V1M5), and a computed tomography (CT) scan showed subarachnoid hemorrhage with intracerebral hematoma in the left temporal lobe. Subsequent 3-dimensional CT angiography showed an aneurysm in the M4 segment of the left MCA. The aneurysm of the patient was clipped safely and effectively because of the navigation system in combination with intraoperative angiography. The navigation system was especially useful for estimating the proximal part of the parent artery at the brain surface, whereas intraoperative angiography was especially useful for confirming that the proximal portion of the parent artery identified by the navigation system was correct. CONCLUSIONS: We emphasize the importance of choosing the modality of intraoperative imaging according to each characteristic when treating M4 segment aneurysms.

Combined Endoscopic Endonasal and Video-microscopic Transcranial Approach with Preoperative Embolization for a Posterior Pituitary Tumor.

BACKGROUND: Posterior pituitary tumor is rare, and its optimal surgical strategy is undetermined. Surgical removal of posterior pituitary tumors is often complicated by their hypervascularity. Prevention and preparation for excessive hemorrhage is crucial for safe resection. CASE DESCRIPTION: A 69-year-old woman presented with bitemporal hemianopsia and was found to have a sellar tumor with suprasellar extension, resembling a pituitary adenoma. Microscopic transsphenoidal resection was attempted but was interrupted by a massive intraoperative hemorrhage. Pathologic diagnosis was a spindle cell oncocytoma, and she was referred to our institution. She underwent preoperative embolization to decrease tumor vascularity, and resection was performed using a combined endoscopic endonasal and video-microscopic transcranial approach, using a 4K three-dimensional (3D) video microscope. The final diagnosis was a posterior pituitary tumor with immunopositivity for thyroid transcription factor-1, with preferred interpretation as a pituicytoma. CONCLUSIONS: A combined endonasal and transcranial approach with preoperative embolization is a useful strategy for hypervascular posterior pituitary tumors. A 4K 3D video microscope is compact, and it provides high-resolution images, contributing larger surgical space and facilitating a multi-team surgery.

Primary Intracranial Rhabdomyosarcoma in the Cerebellopontine Angle Resected After Preoperative Embolization.

BACKGROUND: Primary intracranial rhabdomyosarcoma is a very rare malignant tumor. Owing to moderately vascular and firm characteristics of the tumor, complete removal without complications is often difficult. In pediatric patients, the volume of total blood is less than in adults, and minimal intraoperative hemorrhage is desirable. CASE DESCRIPTION: A 6-year-old boy presented with ataxia and was found to have a large cerebellopontine angle tumor and hydrocephalus. The patient underwent preoperative coil embolization of the anterior inferior cerebellar artery to decrease tumor vascularity, and gross total removal was achieved on the same day via a suboccipital approach. Pathologic diagnosis was rhabdomyosarcoma. CONCLUSIONS: Successfully resection of primary intracranial rhabdomyosarcoma was achieved after preoperative embolization. Tumor vascularity was significantly reduced, and gross total removal was achieved safely with less hemorrhage.

Stroke while driving: Frequency and association with automobile accidents.

Background Cardiovascular events while driving have occasionally been reported. In contrast, there have been few studies on stroke while driving. Aim The objectives of this study were to (1) report the frequency of stroke while driving and (2) evaluate its association with automobile accidents. Methods Clinical data prospectively acquired between January 2011 and December 2016 on 2145 stroke patients (1301 with ischemic stroke, 585 with intracerebral hemorrhage, and 259 with subarachnoid hemorrhage) were reviewed to identify patients who sustained a stroke while driving. The ratio of driving to performing other activities was evaluated for each stroke type. Furthermore, the drivers' response to stroke was reviewed to understand how automobile accidents occurred. Results Among the 2145 patients, 85 (63 ischemic stroke, 20 intracerebral hemorrhage, and 2 subarachnoid hemorrhage) sustained a stroke while driving. The ratio of driving to performing other activities was significantly higher in ischemic stroke (4.8%) than in intracerebral hemorrhage (3.4%) or subarachnoid hemorrhage (0.8%). A majority of drivers either continued driving or pulled over to the roadside after suffering a stroke. However, 14 (16%) patients were involved in automobile accidents. In most patients, an altered mental status due to severe stroke was the presumed cause of the accident. Conclusion Stroke occurred while driving in 4.0% of all strokes and accidents occurred in 16% of these instances.