A Compendium of Modern Minimally Invasive Intracerebral Hemorrhage Evacuation Techniques

BACKGROUND

Minimally invasive intracerebral hemorrhage (ICH) evacuation has gained popularity with success in early-phase clinical trials. This procedure, however, is performed in very different ways around the world.

OBJECTIVE

To provide a technical description of these strategies that facilitates comparison and aids decisions in which surgery to perform, and to inform further improvements in minimally invasive ICH evacuation.

METHODS

Major authors of clinical trials evaluating each of the main techniques were contacted and asked to supply a case example and technical description of their respective surgeries.

RESULTS

Five major techniques are presented including stereotactic thrombolysis, craniopuncture, endoscopic, endoscope-assisted, and endoport-mediated. Techniques differ in numerous ways including the size of the cranial access, the size of the access corridor through the brain to the hematoma, and the evacuation strategy. Regarding cranial access, a burr hole is created in stereotactic thrombolysis and craniopuncture, a small craniectomy in endoscopic, and a small craniotomy in the other 2. Access corridors through the parenchyma range from 3 mm in craniopuncture to 13.5 mm in the endoport-mediated evacuation. Regarding evacuation strategies, stereotactic thrombolysis and craniopuncture rely on passive drainage from a catheter placed during surgery that remains in place for multiple days, while the other 3 techniques rely on active evacuation with suction and bipolar cautery.

CONCLUSION

Future comparative clinical trials may identify the advantageous components of each strategy and contribute to improved outcomes in this patient population.

MRI characteristics of syringomyelia associated with foramen magnum arachnoiditis: differentiation from Chiari malformation

BACKGROUND

It is important to distinguish foramen magnum arachnoiditis (FMA) from Chiari malformation (CM) before surgery because the operative strategies for these diseases differ. In the current study, we compared pretreatment magnetic resonance imaging (MRI) of FMA with CM and investigated the MRI findings useful to differentiate between these diseases.

METHODS

We retrospectively reviewed patients with FMA or CM aged ≥ 18 years who underwent surgeries at our institution between 2007 and 2019. The morphologies of the syrinx, neural elements, and posterior cranial fossa were preoperatively evaluated with MRI. We used the receiver operating characteristic (ROC) curve for the fourth ventricle-to-syrinx distance (FVSD).

RESULTS

Ten patients with FMAs and 179 with CMs were included. FVSD in the FMA group was significantly shorter than that in the CM group (7.5 mm [IQR, 2.8-10 mm] in FMA vs. 29.9 mm [IQR, 16.3-52.9 mm] in CM, p < 0.0001). The other MRI findings that showed the height, size, and length of the syrinx; size of the foramen magnum; degree of cerebellar tonsillar descent; shape of the cerebellar tonsil; and dorsal subarachnoid space at the foramen magnum differed significantly between the two groups. The ROC curve analysis showed that patients whose FVSD was less than 11 mm could be diagnosed with FMA with a specificity of 90% and sensitivity of 96%.

CONCLUSIONS

A more cranial syrinx development (FVSD < 11 mm) appears to be the characteristic MRI finding in FMA.

Modified Computed Tomography Classification for Chronic Subdural Hematoma Features Good Interrater Agreement: A Single-Center Retrospective Cohort Study

OBJECTIVE

The present study aimed to establish whether our modified Nakaguchi computed tomography (CT) classification improves the interrater agreement of chronic subdural hematoma (CSDH) classification and prediction of CSDH recurrence relative to 2 other CT classifications.

METHODS

This retrospective study considered 277 consecutive patients with CSDH and 307 hematomas treated with burr-hole surgery between January 2009 and December 2018. Two neurosurgeons blinded to patients' clinical data classified the CT scans of patients with CSDH into 4 or 5 types according to the Nomura classification (high, iso, low, mixed, and layering), Nakaguchi classification (homogenous, laminar, separated, and trabecular), and our modified Nakaguchi classification (homogenous, gradation, laminar, separated, and trabecular). The κ statistic was used to evaluate the interrater agreement of the 3 CT classifications. Univariable and multivariable logistic regression analyses were used to calculate odds ratios for CSDH recurrence.

RESULTS

κ values of the modified, Nakaguchi, and Nomura classification were 0.78, 0.63, and 0.70, respectively. During the 3 months follow-up, the recurrence rate for CSDH was 11.4% (35/307 hematomas). Of the types defined by the modified classification, the gradation type was associated with the highest recurrence (mean recurrence rate, 15.9% ± 0.3%). Multivariable logistic regression analyses showed that a gradation-type hematoma, as defined with the modified classification, was an independent risk factor associated with recurrence (odds ratio, 2.36; 95% confidence interval, 1.11-4.98; P = 0.025).

CONCLUSIONS

The modified classification was useful for preoperative CT classification of CSDH and the prediction of recurrence, with high agreement between raters.

Global impact of COVID-19 on stroke care

Background

The COVID-19 pandemic led to profound changes in the organization of health care systems worldwide.

Aims

We sought to measure the global impact of the COVID-19 pandemic on the volumes for mechanical thrombectomy, stroke, and intracranial hemorrhage hospitalizations over a three-month period at the height of the pandemic (1 March–31 May 2020) compared with two control three-month periods (immediately preceding and one year prior).

Methods

Retrospective, observational, international study, across 6 continents, 40 countries, and 187 comprehensive stroke centers. The diagnoses were identified by their ICD-10 codes and/or classifications in stroke databases at participating centers.

Results

The hospitalization volumes for any stroke, intracranial hemorrhage, and mechanical thrombectomy were 26,699, 4002, and 5191 in the three months immediately before versus 21,576, 3540, and 4533 during the first three pandemic months, representing declines of 19.2% (95%CI, −19.7 to −18.7), 11.5% (95%CI, −12.6 to −10.6), and 12.7% (95%CI, −13.6 to −11.8), respectively. The decreases were noted across centers with high, mid, and low COVID-19 hospitalization burden, and also across high, mid, and low volume stroke/mechanical thrombectomy centers. High-volume COVID-19 centers (−20.5%) had greater declines in mechanical thrombectomy volumes than mid- (−10.1%) and low-volume (−8.7%) centers (p < 0.0001). There was a 1.5% stroke rate across 54,366 COVID-19 hospitalizations. SARS-CoV-2 infection was noted in 3.9% (784/20,250) of all stroke admissions.

Conclusion

The COVID-19 pandemic was associated with a global decline in the volume of overall stroke hospitalizations, mechanical thrombectomy procedures, and intracranial hemorrhage admission volumes. Despite geographic variations, these volume reductions were observed regardless of COVID-19 hospitalization burden and pre-pandemic stroke/mechanical thrombectomy volumes.

Decline in subarachnoid haemorrhage volumes associated with the first wave of the COVID-19 pandemic

Background

During the COVID-19 pandemic, decreased volumes of stroke admissions and mechanical thrombectomy were reported. The study’s objective was to examine whether subarachnoid haemorrhage (SAH) hospitalisations and ruptured aneurysm coiling interventions demonstrated similar declines.

Methods

We conducted a cross-sectional, retrospective, observational study across 6 continents, 37 countries and 140 comprehensive stroke centres. Patients with the diagnosis of SAH, aneurysmal SAH, ruptured aneurysm coiling interventions and COVID-19 were identified by prospective aneurysm databases or by International Classification of Diseases, 10th Revision, codes. The 3-month cumulative volume, monthly volumes for SAH hospitalisations and ruptured aneurysm coiling procedures were compared for the period before (1 year and immediately before) and during the pandemic, defined as 1 March–31 May 2020. The prior 1-year control period (1 March–31 May 2019) was obtained to account for seasonal variation.

Findings

There was a significant decline in SAH hospitalisations, with 2044 admissions in the 3 months immediately before and 1585 admissions during the pandemic, representing a relative decline of 22.5% (95% CI −24.3% to −20.7%, p<0.0001). Embolisation of ruptured aneurysms declined with 1170–1035 procedures, respectively, representing an 11.5% (95%CI −13.5% to −9.8%, p=0.002) relative drop. Subgroup analysis was noted for aneurysmal SAH hospitalisation decline from 834 to 626 hospitalisations, a 24.9% relative decline (95% CI −28.0% to −22.1%, p<0.0001). A relative increase in ruptured aneurysm coiling was noted in low coiling volume hospitals of 41.1% (95% CI 32.3% to 50.6%, p=0.008) despite a decrease in SAH admissions in this tertile.

Interpretation

There was a relative decrease in the volume of SAH hospitalisations, aneurysmal SAH hospitalisations and ruptured aneurysm embolisations during the COVID-19 pandemic. These findings in SAH are consistent with a decrease in other emergencies, such as stroke and myocardial infarction.

A Smartphone Application as a Telemedicine Tool for Stroke Care Management

Since smartphone applications are revolutionizing telemedicine, a new application specifically for stroke care (JOIN) was designed. Addition of the JOIN smartphone application to the stroke treatment workflow in our hospital was assessed. JOIN has key functions that may improve the care of stroke patients, including the ability to (1) exchange information such as patient data and medical images in real-time throughout the entire process of patient management; (2) track each step of the protocol from door to discharge; and (3) facilitate real-time interaction of all team members via text, audio, and a video chat system. Two periods, 2.7 years before the implementation of JOIN (Pre-JOIN) with 37 patients and 2.2 years after (Post-JOIN) with 54 patients, were compared, and the workflow for all 91 patients who had a cerebral infarction and were treated with tissue plasminogen activator (tPA) and/or thrombectomy between October 2012 and July 2017 was reviewed. There were noticeable reductions in overall patient management time, including times for door-to-imaging, starting tPA treatment, and endovascular intervention with JOIN. Staff members were unanimously satisfied with JOIN, due to the increased efficiency of information exchange and the ability for real-time discussions with different professionals when needed. No significant changes in patient outcomes (as assessed by modified Rankin Scale [mRS] scores) at 3 months and in the total cost for the treatment were observed. A smartphone-based application with the capability of sharing information instantaneously among healthcare professionals facilitated time-sensitive, acute care of ischemic stroke patients.

Four-dimensional digital subtraction angiography for exploration of intraosseous arteriovenous fistula in the sphenoid bone

Background

Intraosseous arteriovenous fistula (AVF) is a rare clinical entity that typically presents with symptoms from their effect on surrounding structures. Here, we report a case of intraosseous AVF in the sphenoid bone that presented with bilateral abducens palsy.

Case Description

A previously healthy man presented with tinnitus for 1 month, and initial imaging suspected dural AVF of the cavernous sinus. Four-dimensional digital subtraction angiography (4D-DSA) imaging and a three-dimensional (3D) fused image from the bilateral external carotid arteries revealed that the shunt was in a large venous pouch within the sphenoid bone that was treated through transvenous coil embolization. His symptoms improved the day after surgery.

Conclusion

This is a case presentation of intraosseous AVF in the sphenoid bone and highlights the importance of 4D-DSA and 3D fused images for planning the treatment strategy.

Communication-type smartphone application can contribute to reducing elapsed time to reperfusion therapy

Background and objectives

Communication-type medical smartphone applications enable text, neuroimaging, photos, and videos to be shared securely among the stroke team. Our aim was to investigate whether use of a smartphone application would shorten the duration from admission to reperfusion therapy in patients with hyper-acute ischemic stroke.

Methods

Enrolled were acute ischemic stroke patients who underwent reperfusion therapy (intravenous tissue plasminogen activator (IV t-PA) and mechanical thrombectomy (MT)) at our hospital between October 2012 and September 2018. We divided the patients into two groups based on the date of availability on smartphones of communication-type medical application: (1) Control group, conventional communication prior to September 2015, and (2) App group, communication via the smartphone app from October 2015 onwards. We compared door-to-image time (DIT), image-to-needle time (INT), door-to-needle time (DNT) for thrombolysis, and DIT, image-to-puncture time (IPT), and door-to-puncture time (DTP) for thrombectomy between the groups.

Results

We retrospectively enrolled 139 patients (68% male; median age, 69 years; median NIHSS score, 7) who were assigned into the App group (n = 86) and Control group (n = 53). Of the overall patients, 109 underwent IV t-PA (IV t-PA alone, 79 patients), and 63 underwent MT (MT alone, 30 patients), and 33 patients underwent combined IV t-PA and MT. There was no significant difference in DIT between the App and Control groups (23 min vs. 22 min, p = 0.493). DNT, DPT, INT, and IPT were significantly shorter in the App group than in the Control group (DNT, 62 min for the App group vs. 72 min for Control group, p = 0.038; INT, 42 vs. 48 min, p = 0.009; DPT, 106 vs. 129 min, p = 0.046; IPT, 89 vs. 117 min, p = 0.004).

Conclusion

The present findings indicate that communication-type medical smartphone apps have potential for shortening the time elapsed between admission and reperfusion therapy, especially INT and IPT.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10072-021-05132-2.

Visual complications after coil embolization of internal carotid artery aneurysms at the ophthalmic segment

BACKGROUND

Coil embolization of aneurysms of the ophthalmic segment of the internal carotid artery (ICA-OphA ANs) has potential risks of visual complications. We analyzed this risk and focused on the relationship of the ophthalmic artery (OphA) origin with the aneurysm neck.

METHODS

From January 2003 to April 2018, 179 unruptured ICA-OphA ANs were treated with endovascular surgery in our institution. Two ruptured and four aneurysms with missing data were excluded. Finally, 173 unruptured aneurysms were included in this study. The aneurysms were classified into three groups according to the location of the OphA origin: Separate, Shared, and Dome type. We retrospectively assessed visual complications based on the relationship between types of aneurysm and postoperative angiographic findings for the OphA.

RESULTS

Visual deficits remained permanent in eleven cases (6.4%). In the Dome type, visual complications were significantly more frequent compared to the Separate type. Change in the OphA flow was significantly associated with a higher complication rate of 2.9%, but patients with changed OphA flow had a significant rate of 7.5% (p = 0.020). We found no significant difference in the incidence of visual complications concerning the use of perioperative antithrombotic therapy.

CONCLUSIONS

The location of OphA origin regarding the aneurysmal neck and postoperative OphA flow were significantly correlated with the visual outcome after coil embolization for ICA-OphA ANs. Post-procedural flow in the OphA was an important factor affecting the rate of ischemic retinal complications. Retinal embolic events occurred with preserved flow in the OphA, albeit at a lower rate.

Thoracic and lumbar spine pedicle morphology in Japanese patients

PURPOSE

Pedicle morphology is important for intraoperative surgical anatomy and to define pedicle screw design and parameters. However, differences of pedicle size according to ethnicity and gender are not well studied. The purpose of this study is to investigate morphological characteristics of the pedicle in Japanese patients for determining adequate screw size and optimal surgical planning.

METHODS

We investigated thoracic and lumbar pedicle morphology in Japanese patients using computed tomography (CT) measurements and analyzed the standard size of pedicles on upper thoracic to lumbar spine CT images in 227 Japanese patients.

RESULTS

Gender had a larger impact on the shape and size of pedicles than racial differences. In the distribution of pedicle width, we calculated the ratio of values less than 4.5 mm, that in females resulted to be over 30% for the Th3-Th9 segment, and particularly high, above 60% at Th4 and Th5.

CONCLUSION

Our measurement analysis showed that pedicle morphological parameters in Japanese patients showed tendency to be smaller to those found in other studies, and particularly in female patients, they were statistically significantly smaller. Adequate transpedicular instrumentation for Japanese patients will require smaller size pedicle-related devices that will match our anatomical findings to achieve safe device placement. In addition, serving ethnically non-homogenous patient population can require further to spinal morphometric for precise device selection.

Visualization of extracranial-intracranial bypass in moyamoya patients using intraoperative three-dimensional digital subtraction angiography with intravenous contrast injection and robotic C-arm: patient series

BACKGROUND

The authors describe a noninvasive intraoperative imaging strategy of three-dimensional (3D) digital subtraction angiography (DSA) with intravenous (IV) contrast injection, using indocyanine green (ICG) as a test bolus, during extracranial-intracranial (EC-IC) bypass surgery for moyamoya disease.

OBSERVATIONS

Four patients underwent EC-IC bypass surgery in a hybrid operating room. During the surgery, bypass patency was verified using ICG videoangiography and Doppler ultrasonography. After skin closure, the patients under anesthesia underwent IV 3D-DSA with a robotic C-arm in which the scan delay time for the 3D-DSA scan was estimated from the arrival time of ICG during the ICG videoangiography. One day after the surgery, the patients underwent magnetic resonance angiography (MRA). The IV 3D-DSA images were retrospectively compared with those obtained with other modalities. Good bypass patency was confirmed on IV 3D-DSA, ICG videoangiography, Doppler ultrasonography, and postoperative MRA in all cases. The delay time determined using ICG videoangiography as a test bolus resulted in IV 3D-DSA with adequate image quality, allowing assessment of the spatial relationships between the vessels and anastomoses from all directions.

LESSONS

To evaluate bypass patency and anatomical relationships immediately after EC-IC bypass surgery, IV 3D-DSA may be a useful modality. ICG videoangiography can be used to determine the scan delay time.

A Case of Severe Common Carotid Artery Stenosis Who Developed Cerebellar Infarction after Cervical Irradiation

Objective

We report a case of cerebellar infarction caused by radiation-induced common carotid artery stenosis.

Case Presentation

The patient was a 72-year-old man who underwent irradiation for hypopharyngeal carcinoma 13 years ago. He was referred for asymptomatic left common carotid artery stenosis, but was brought to our hospital by ambulance with transient dysarthria and right facial dysesthesia 2 days after referral. Magnetic resonance imaging (MRI) revealed acute infarction in the left cerebellar hemisphere, and digital subtraction angiography (DSA) demonstrated that the blood flow in the left internal carotid artery perfused the left posterior inferior cerebellar artery (PICA) retrogradely through the left posterior communicating artery. The patient underwent carotid artery stenting (CAS) for left common carotid artery stenosis and blood flow in the left PICA improved; however, in-stent restenosis was revealed during follow-up. Percutaneous transluminal angioplasty (PTA) for in-stent restenosis was performed 9 months after the surgery.

Conclusion

We reported a rare case of ischemia in the PICA area caused by radiation-induced common carotid artery stenosis. Although CAS is recommended for the treatment of radiation-induced carotid artery stenosis, careful treatment and follow-up are needed to prevent perioperative complications and detect in-stent restenosis after CAS.

Direct carotid exposure approach in the treatment of anterior circulation unruptured intracranial aneurysms for elderly patients

BACKGROUND AND PURPOSE

The direct carotid exposure approach (DCEA) is a technical option for elderly patients with severe vessel tortuosity due to arteriosclerosis. We evaluated complications related to antiplatelet/anticoagulant management and compared the DCEA to standard transfemoral/transbrachial approaches (TFBA) in the treatment of unruptured intracranial aneurysms for elderly patients.

METHODS

From August 2017 to August 2020, 52 patients (53 procedures) aged over 75 years with unruptured aneurysms in the anterior circulation were treated at our institution. All patients received dual antiplatelet drugs before the procedure. Eleven patients (21.2%) (12 procedures) were treated with the DCEA. The rest were treated with TFBA. The main indication of the DCEA was an unfavorable aortic arch or vessel tortuosity. Complications and the duration of the procedure were compared between the two groups.

RESULTS

There were no significant differences between the two groups in age, aneurysm location, preoperative antiplatelet use, heparin use, or maximum activated clotting time (ACT) values. All endovascular treatments were successfully performed by DCEA. Among all parameters, the DCEA group had only bigger average aneurysm diameter (14 mm) and higher number of pipeline embolic device (PED) placement (58%). Time to the guiding-catheter placement was not significantly different between the groups (DCEA vs TFBA = 31.0 min vs 24.7 min, p = 0.178).　No significant complications of DCEA, such as subcutaneous hematomas, were observed.　.

CONCLUSION

Even with the use of antiplatelet and anticoagulation therapy, the DCEA can be performed safely for unruptured aneurysms in elderly patients.

Flow Diverter Apposition in Patients with Large or Giant Intracranial Aneurysms Evaluated on Three-Dimensional Fusion Images Acquired by High-Resolution Cone-Beam Computed Tomography and Digital Subtraction Angiography

OBJECTIVE

To investigate flow diverter (FD) apposition on fused images acquired by high-resolution cone-beam computed tomography (CBCT) and 3-dimensional (3D) digital subtraction angiography.

METHODS

Patients with large or giant internal carotid artery aneurysms treated with Pipeline FDs who underwent CBCT imaging at our institution between October 2016 and May 2019 were included. Two neurosurgeons measured the maximum malapposition between FDs and vessel walls on 3D fusion images of high-resolution CBCT images displaying the FD and 3D digital subtraction angiography images displaying the vessels. Associations between the relative malapposition, FD diameter, vessel diameter, proximal and distal vessel diameter discrepancy, and siphon angle were evaluated by linear regression analysis. Inter-rater and intermethod (3D and 2D image) agreements of the malapposition measurements were assessed by Bland-Altman analysis and by interclass correlation coefficients.

RESULTS

Images of 2 patients were excluded because of image artifacts or fusion errors, and 3D fusion images were acquired in the remaining 26 patients. Our results did not suggest that relative malapposition was associated with vessel diameter (P = 0.12), vessel diameter discrepancy (P = 0.60), or syphon angle (P = 0.34), but relative malapposition increased by an estimated 13% (95% confidence interval: 4%-23%, P = 0.006) for each 1 mm increase in FD diameter. Inter-rater and intermethod agreements for apposition measurements were excellent and good, respectively.

CONCLUSIONS

Three-dimensional fusion images provided clear visualization of structures of both the stent and parent artery with excellent diagnostic reliability. Careful deployment may be needed for FDs with larger diameters, as they tended to have larger relative malapposition.

Significantly high concentrations of vascular endothelial growth factor in chronic subdural hematoma with trabecular formation

The underlying mechanism of chronic subdural hematoma (CSDH) after minor head injury is complex, probably due to mechanical injury of the arachnoid membrane, hematological coagulopathy, and pathological angiogenesis in the dura caused by inflammatory cytokines including vascular endothelial growth factor (VEGF). To confirm whether VEGF might be a reliable predictive biomarker for the natural history of CSDH, including progression and recurrence, we analyzed the correlation of VEGF concentration in the subdural fluid with CT findings and clinical features, including interval from minor head injury. Based on CT classification by hematoma density, the mean concentration of VEGF in hematoma fluid was found to be highest in the trabecular group, whereas the recurrence of CSDH was most frequent in the separated group in which VEGF concentration was low. There was a significant correlation between VEGF concentration and the CT classification. Furthermore, only in the trabecular group, a significant negative correlation between the VEGF concentration and interval from minor head injury to surgery was observed. These results suggest that VEGF concentration in the hematoma alone could not be a reliable predictive biomarker for the natural history of CSDH including its recurrence. Amongst the classified groups of CSDH, the trabecular group is likely to follow a different time course of VEGF concentration in the hematoma fluid compared to the other three groups.

Negative-pressure hydrocephalus in the course of a complex postoperative intracranial pressure disturbance: illustrative case

BACKGROUND

Negative-pressure hydrocephalus (NePH) is a rare clinical entity that presents on the background of ventriculomegaly with atypical symptoms. Its diagnosis is difficult, and some patients experience several shunt revisions until the proper solution is found.

OBSERVATIONS

The authors present a patient who developed acute deterioration due to iatrogenic NePH after surgery for a vertebral artery thrombosed giant aneurysm. The deterioration occurred after the insertion of a lumbar drain by which the authors intended to reduce a postoperative subcutaneous cerebrospinal fluid (CSF) collection. The drainage created an unexpected negative-pressure gradient in the CSF spaces, which resulted in NePH. Interventions, such as extraventricular drainage and blood patch, corrected the negative transmantle pressure and stabilized the patient’s condition.

LESSONS

Because the pathophysiology of NePH is theoretically considered to be caused by negative transmantle pressure, the intervention should be performed in order to deal with the coexistence of obstruction in the CSF pathways and a CSF leak. A blood patch would be an effective option in treating the CSF leak when the site of leakage is certain. This is the first case in which a blood patch was effectively applied in the treatment for NePH with a favorable outcome without any permanent CSF diversion.

Alteration of FOXM1 expression and macrophage polarization in refractory meningiomas during long-term follow-up

Malignant progression of grade I meningioma with a long latency period is rare. We experienced grade II/III meningiomas with refractoriness and recurrence from grade I meningiomas through multiple surgeries. Three patients with atypical/anaplastic meningioma experienced long-latent recurrence after initial surgery for grade I (meningothelial) meningioma without following adjuvant radiotherapy were included in the present study. Histological findings of the initial tumors in all cases (case 1, 2, and 3) revealed meningothelial meningioma with 1%, 5%, and 0.1% MIB-1 positive cells, respectively. Surprisingly, magnetic resonance imaging (MRI) detected a recurrent tumor 2, 12, and 12 years after the initial operation, respectively. Case 1 was atypical meningioma after third recurrence, and case 2 and 3 were anaplastic meningioma after second and third recurrence, respectively. The patient in case 2 received adjuvant radiotherapy. In case 2, the tumor recurred intracranial and distant metastasis to the lung with huge substantial pleural effusion was detected. To investigate the pathogenesis of malignant progression from benign to malignant meningioma, CD163/CD68 expression by immunohistochemically and FOXM1 mRNA expression by RT-PCR were compared using surgical specimens from initial and recurrent tumors in all three patients. The ratio of CD163/CD68 positivity and FOXM1 mRNA expression were increased in recurrent tumors compared with matched initial tumors. CD163 and FOXM1 expression levels were induced even in recurrent grade I meningioma, suggesting that macrophage polarization and pro-mitotic transcriptional factor might be associated with clinical behavior of meningioma and be useful as a prediction marker for malignant progression. Careful long-term follow-up is important for early diagnosis of malignant progression in meningiomas, even if grade I meningioma is completely resected. Development of a multidisciplinary approach including radiation and novel molecular targeted therapy is expected for recurrent and malignant meningiomas.

CS-01 Rapid Recurrence and Anaplastic Transformation of a Pilocytic Astrocytoma in an Elderly Patient

BACKGROUND: Rapid recurrence of a pilocytic astrocytoma with anaplastic transformation is extremely rare. The case of an elderly patient with a cerebellar pilocytic astrocytoma with anaplastic transformation during short-term follow-up is reported. CASE DESCRIPTION: An 83-year-old woman presented initially with dizziness and a gait deviation to the right. Magnetic resonance imaging (MRI) demonstrated a homogeneously enhanced mass in the right cerebellar hemisphere, and the tumor was subtotally removed by right suboccipital craniotomy. Histological examination showed that the tumor cells contained eosinophilic cytoplasm and spindle-shaped processes with Rosenthal fibers and eosinophilic granular bodies, diagnosed as a typical pilocytic astrocytoma (PA). The MIB-1 index was less than 1%. The patient did not receive postoperative adjuvant radiation and chemotherapy. Two months after surgery, MRI showed growth of the residual tumor adjacent to the fourth ventricle, causing obstructive hydrocephalus. She underwent surgery again, and the tumor was totally removed. Histological findings showed mitotic cells and increased cellularity compared with the primary tumor, which was compatible with anaplastic transformation of PA with a MIB-1 index of 50%. Postoperatively, she was observed with best supportive care without postoperative adjuvant therapy. Nine months after the second operation, she died due to tonsillar herniation and obstructive hydrocephalus caused by a recurrent tumor. An autopsy was performed. CONCLUSION: It is extremely rare, as in the present case, that a cerebellar PA in an elderly patient recurs rapidly with anaplastic transformation, despite deferred postoperative adjuvant therapy including radiation and chemotherapy A novel molecular-targeted therapy is needed for anaplastic PA showing aggressive biological behavior.

PEDT-03 A clinical trial of dendritic cell-based immunotherapy for refractory brain tumors in children

Background/Objectives: Relapse or refractory brain tumor in childhood continue to have a dismal prognosis in spite of developing multidisciplinary treatment. Cancer immunotherapy is newly expected as next promising treatment for highly aggressive pediatric cancer. This trial was designed to evaluate the safety and clinical responses to an immunotherapy with fusions of dendritic cells (DCs) and tumor cells in patients with malignant brain tumors. Design/Methods: Patients with histopathologically confirmed high-grade or recurrent brain tumor were eligible for our immunotherapy. Autologous cultured tumor cells obtained from surgical specimens were fused with autologous DCs using polyethylene glycol. The fusion cells (FC) were inoculated intradermally in the cervical region and repeated 3–10 times in each 28–84 days cycle. Toxicity, progression-free survival (PFS), and overall survival (OS) of this trial were evaluated. Results: Six patients were enrolled, three with high grade glioma and three with ependymoma. Median age at first course of immunotherapy was 10 years (range 8–25 years) and median time of follow-up from first course of immunotherapy was 13.5 months (range 3–33 months). All patients with immunotherapy were well tolerated and no adverse event without local erythema in injected site. Median progression free survival and overall survival were 18 months and 18.5 months, respectively. Conclusions: FC immunotherapy with autologous DCs and tumor cells for brain tumor in children and young adults were extremely well tolerated and encouraging. Further phase II study of FC immunotherapy is planned to improve prognosis and overcome treatment related neurological sequelae for highly malignant tumors.

COT-08 Analysis of prognosis of biopsy/partial resection cases of malignant glioma

Introduction: Malignant glioma is the most common and aggressive primary brain tumor and requires multimodality treatment. Regarding surgical treatment, it is desirable to achieve maximum resection while considering function preservation. There is consensus that the survival prognosis is prolonged in gross or subtotal resection. However, there are cases in which biopsy or partial resection is performed due to the spread of lesions at the time of onset, underlying diseases, and social background. The purpose of this study was to retrospectively analyze the cases of malignant glioma at our university and to find out the factors related to the prognosis of cases in which removal was insufficient.

Target: 55 cases of malignant glioma treated at our university since 2013 who underwent biopsy or partial resection.

Method: Overall/progression-free survival period is the end point, and parameters are age, bevacizumab use, pathological diagnosis, photodynamic diagnosis use at operation, immunotherapy, ventricular invasion, contralateral invasion, sex, preoperative Performance Status (PS), postoperative PS, left or right, navigation use, steroid use, anticonvulsant drug type, radiation, IDH mutation, 1p19q co-deletion, MGMT methylation, TERT mutation, p53 mutation, biopsy or partial resection. After narrowing down the evaluation items by univariate analysis(Logrank test), multivariate analysis(Cox proportional hazard model)was performed.

Result: The univariate analysis was significant in 5 items including bevacizumab use, radiation therapy, levetiracetam use, postoperative PS70 or higher, and partial resection instead of biopsy. Multivariate analysis detected two statistically significant differences, bevacizumab use and post-operative PS70 and above. There was no difference in the timing of bevacizumab use.

Consideration: In poorly resection cases, the weight of postoperative treatment is high, so continuity of treatment and selection of postoperative treatment are important, and maintenance of ADL and use of bevacizumab are significant among them.

Clinical predictors of surgical outcomes of severe carpal tunnel syndrome patients: utility of palmar stimulation in a nerve conduction study

Background

Carpal tunnel syndrome is a common peripheral nerve compression disorder. However, there is no established opinion regarding the predictors of symptom improvement after surgery. This study aimed to identify the predictors of surgical outcomes of severe carpal tunnel syndrome patients.

Methods

In the patients who underwent a carpal tunnel syndrome surgery, we selected the patients who had a preoperative Bland’s classification of grade 5 or 6, and assessed for the changes in Bland’s classification grade before and after surgery. Those who showed improvement from preoperative grades 5–6 to postoperative grades 1–4 comprised the improvement group. In contrast, those who did not show improvement and had postoperative grades 5 or 6 comprised the non-improvement group. In a nerve conduction study, amplitudes of the compound muscle action potential and sensory nerve action potential of the palms were assessed between the improvement and non-improvement groups.

Results

Among the 60 hands of 46 patients who had a preoperative Bland’s classification of grade 5 or 6, 49 hands of 37 patients comprised the improvement group, and 11 hands of 9 patients comprised the non-improvement group. The amplitudes of the compound muscle action potential and sensory nerve action potential of the palms before surgery were significantly higher in the improvement group. The degree of improvement in Bland’s classification grade was correlated with the degree of clinical symptom improvement.

Conclusions

Amplitudes of compound muscle action potential and sensory nerve action potential before surgery induced by palmar stimulation can predict improvements in nerve conduction study scores and clinical findings after surgical treatment.

[Technical "Tips" for Epidural Tenting Using DuraGen^® for Surgical Management of Large Dural Defects:A Technical Note]

DuraGen^®, an absorbable, engineered collagen-based artificial graft was introduced in Japan in September 2019 for cranial, transsphenoidal, and spinal surgeries. In addition to its efficacy and safety profile, owing to sutureless dural repair, DuraGen^® is widely accepted by neurosurgeons. Direct tenting with DuraGen^® is occasionally required in patients with large dural defects, particularly in cases of tumors adherent to the dura. To overcome this limitation, we introduced a surgical technique for epidural tenting using DuraGen^®. A 78-year-old man with a history of alexia underwent craniotomy for resection of a left temporal lobe metastatic tumor. We completely removed the recurrent tumor, which was strongly adherent to the dura in the middle cranial fossa. A layer of DuraGen^® was used as a subdural underlay beneath the autologous dura to close the wide dural defect. To avoid postoperative epidural fluid collection, we retracted the DuraGen^® from the epidural aspect and interposed several pieces of muscle, which were sutured on the subdural aspect to ensure that the muscle pieces securely plugged the dural defect. We placed an additional overlay of DuraGen^® along the autologous dura. The patient's postoperative course was uneventful without cerebrospinal fluid leakage, tension pneumocephalus, or wound infection. Reoperations for tumor resection, particularly surgical procedures for refractory meningiomas and malignant tumors cause increasing fragility and wide defects of the dura. DuraGen^® placement enables sutureless closure and is less time-consuming. Our technique of epidural direct tenting with DuraGen^® using muscle pieces sutured on the subdural aspect could be useful in patients with significantly large dural defects and can prevent postoperative epidural fluid collection to ensure complete dural sealing.

4D Digital Subtraction Angiography for the Temporal Flow Visualization of Intracranial Aneurysms and Vascular Malformations

PURPOSE

To assess the benefit and radiation dose of four-dimensional (4D) digital subtraction angiography (DSA) - a time resolved three-dimensional (3D) DSA application - to evaluate the flow and architecture of aneurysms and vascular malformations.

METHODS

All patients with cerebrovascular disease were considered who underwent 4D-DSA at our institution between January 2015 and February 2016. For the aneurysm patients, we evaluated the image quality in terms of the visualization of contrast flow in the aneurysm on a 3-point scale (excellent, fair and poor). Interrater agreement between two raters was estimated using Cohen's Kappa statistics. For the shunt disease patients, the additional information obtained from the 4D-DSA was described for each disease. The median radiation dose and volume of contrast medium required for the acquisitions were estimated.

RESULTS

A total of 173 patients underwent 4D-DSA; 126 intracranial aneurysms, 10 arteriovenous malformations (AVM), 15 dural arteriovenous fistula (dAVF) and 22 other diseases. For aneurysm patients, excellent and fair visualization of the intra-aneurysmal flow was observed in 27.7%, 72.3%, and excellent (κ = 0.9) agreement between the raters was found. For AVM and dAVF patients, 4D-DSA clarified the complex vasculature by viewing the discrete time phase of contrast filling. Median radiation dose for intracranial lesions was 79.6 mGy for 6s 4D-DSA, and 175 mGy for 12s 4D-DSA. The median amount of contrast medium used was 18.0 ml for 6s 4D-DSA and 21.0 ml for 12s 4D-DSA.

CONCLUSIONS

4D-DSA provided additional information regarding intra-aneurysmal flow and contributed to detect different component of nidus or shunt points.

Sex and Genetic Background Effects on the Outcome of Experimental Intracranial Aneurysms

BACKGROUND AND PURPOSE

Intracranial aneurysm formation and rupture risk are, in part, determined by genetic factors and sex. To examine their role, we compared 3 mouse strains commonly used in cerebrovascular studies in a model of intracranial aneurysm formation and rupture.

METHODS

Intracranial aneurysms were induced in male CD1 (Crl:CD1[ICR]), male and female C57 (C57BL/6NCrl), and male 129Sv (129S2/SvPasCrl or 129S1/SvImJ) mice by stereotaxic injection of elastase at the skull base, combined with systemic deoxycorticosterone acetate-salt hypertension. Neurological deficits and mortality were recorded. Aneurysms and subarachnoid hemorrhage grades were quantified postmortem, either after spontaneous mortality or at 7 to 21 days if the animals survived. In separate cohorts, we examined proinflammatory mediators by quantitative reverse transcriptase-polymerase chain reaction, arterial blood pressure via the femoral artery, and the circle of Willis by intravascular latex casting.

RESULTS

We found striking differences in aneurysm formation, rupture, and postrupture survival rates among the groups. 129Sv mice showed the highest rates of aneurysm rupture (80%), followed by C57 female (36%), C57 male (27%), and CD1 (21%). The risk of aneurysm rupture and the presence of unruptured aneurysms significantly differed among all 3 strains, as well as between male and female C57. The same hierarchy was observed upon Kaplan-Meier analysis of both overall survival and deficit-free survival. Subarachnoid hemorrhage grades were also more severe in 129Sv. CD1 mice showed the highest resistance to aneurysm rupture and the mildest outcomes. Higher mean blood pressures and the major phenotypic difference in the circle of Willis anatomy in 129Sv provided an explanation for the higher incidence of and more severe aneurysm ruptures. TNFα (tumor necrosis factor-alpha), IL-1β (interleukin-1-beta), and CCL2 (chemokine C-C motif ligand 2) expressions did not differ among the groups.

CONCLUSIONS

The outcome of elastase-induced intracranial aneurysm formation and rupture in mice depends on genetic background and shows sexual dimorphism.

Spontaneous cerebrospinal fluid otorrhea and pneumocephalus on the contralateral side of the previous cranial surgery

Background

Cerebrospinal fluid (CSF) leaks and pneumocephalus commonly occur due to head trauma or surgical procedures. Spontaneous CSF (sCSF) leaks, however, occur without any clear etiology and are relatively uncommon.

Case Description

An 84-year-old woman presented with the right-sided otorrhea. The patient had a history of a ventriculoperitoneal shunt placement following a subarachnoid hemorrhage treated by clip ligation of a left-sided ruptured cerebral aneurysm 7 years before presentation, with shunt catheter ligation after evidence of intraventricular pneumocephalus 6 years before presentation. At admission, computed tomography (CT) imaging of the head showed enlargement of the lateral ventricles, a right mastoid fluid collection, and a defect of the superior wall of the right petrous bone. We performed a right temporal craniotomy for the repair of the CSF leak. Intraoperatively, it was noted that temporal lobe parenchyma herniated into the mastoid air cells through lacerated dura and a partially defective tegmen mastoideum. The leak point was successfully obliterated with a pericranial graft and reinforced by a collagen sheet and fibrin glue. There was no recurrence of otorrhea postoperatively.

Conclusion

This report presents a very unique case of a patient with a CSF leak and pneumocephalus occurring on the contralateral side of a previous cranial surgery. We accurately identified the defect site with CT imaging and repaired the CSF leak by temporal craniotomy. Awareness of the mechanisms by which sCSF leaks can be caused by aberrant arachnoid granulations is imperative for neurosurgeons.