[Preoperative Embolization of Intracranial Meningioma].

Preoperative embolization(POE)of intracranial meningioma is performed worldwide. Although clear evidence of the effectiveness of POE has not been reported in the literature, the technique plays an important role in open surgery, especially for large or skull base meningiomas. The purposes of embolization include: 1)induction of tumor necrosis, resulting in a safer operation, 2)reduction in intraoperative bleeding, and 3)decrease in operative time. Knowledge of the functional vascular anatomy, embolic materials, and endovascular techniques is paramount to ensure safe embolization. Our standard procedure is as follows: 1)embolization is performed several days before open surgery; 2)in cases with strong peritumoral edema, steroid administration or embolization may be performed immediately prior to surgery; 3)patients undergo the procedure under local anesthesia; 4)the microcatheter is inserted as close as possible to the tumor; 5)particulate emboli are the first-line material; 6)embolization is occasionally performed with N-butyl cyanoacrylate(NBCA)glue; and 7)if possible, additional proximal feeder occlusion with coils is performed. The JR-NET study previous showed the situation regarding intracranial tumor embolization in Japan. Endovascular neurosurgeons should fully discuss the indications and strategies for POE with tumor neurosurgeons to ensure safe and effective procedures.

Endovascular Treatment for Intracranial Artery Dissections in Posterior Circulation.

Intracranial artery dissections (IADs), although uncommon, are an important cause of cerebral infarction and subarachnoid hemorrhage (SAH). Some IADs can heal spontaneously after reconstitution of the vessel lumen with excellent prognosis. Meanwhile, others can progress to stroke that requires treatment. The incidence of IAD in the posterior circulation is higher than that in the anterior circulation. Anterior circulation dissections are more likely to develop into ischemia and posterior circulation lesions into hemorrhage. The mortality rate after IAD among patients with SAH is 19%-83%. Further, the mortality rate of IAD without SAH is 0%-3%. Patients with SAH commonly undergo surgery or receive neuroendovascular treatment (EVT) to prevent rebleeding. However, the treatment of IADs is empirical in the absence of data from randomized controlled trials. Recently, EVT has emerged and is considered for IADs because of its less invasiveness and perceived low rates of procedure-related morbidity with good efficacy. EVT strategies can be classified into deconstructive (involving sacrifice of the parent artery) and reconstructive (preserving blood flow via the parent vessel) techniques. In particular, the number of reports on reconstructive techniques is increasing. However, a reconstructive technique for ruptured IADs has not yet been established. This review aimed to provide an overview of IADs in the posterior circulation managed with EVT by performing a literature search.

Questionnaire Survey of Neurointerventional Simulation Training in the Japanese Society for Neuroendovascular Therapy.

Objective: Simulation training has focused on education and practical training. However, the adoption rate of neurointerventional simulation training in Japan is unknown. Therefore, we sent a questionnaire survey form to consulting specialists from the Japanese Society for Neuroendovascular Therapy (JSNET) to clarify the actual simulation training situation and compare the differences between university hospitals and general hospitals in Japan. Methods: The questionnaire survey was conducted in 243 neurosurgical training facilities that had JSNET consulting specialists between May 31, 2021 and July 31, 2021. The questionnaire survey forms were distributed by Google Forms. Results: A total of 162 facilities responded to the survey (response rate: 66.7%; 35.2% from university hospitals and 64.8% from general hospitals). The adoption rate for simulation training was 53.7%, and it was significantly higher in the university hospitals than in the general hospitals (64.9% vs. 47.6%, p = 0.035). On the simulation effectiveness survey, more than 80% of respondents answered that the simulation training was a useful tool for upskill training. The open-ended question on interventional simulation training showed that there are limiting factors such as financial constraints. Additionally, respondents expressed a desire for a standard neurointerventional simulation training and education program. Conclusion: The adoption rate for simulation training was 53.7% in the training facilities of JSNET, and it was higher in the university hospitals than in the general hospitals. Most of the respondents answered that simulation training is an effective tool to improve neurointerventional skills. They also requested the establishment of simulation training programs and simulation tools.

Transvenous embolization of the direct carotid-cavernous fistula via the pterygoid plexus: illustrative case.

BACKGROUND: Endovascular treatment is the mainstay of treatment for carotid-cavernous fistulas, but endovascular approaches vary widely. The authors report a rare case of a direct carotid-cavernous fistula with cranial nerve symptoms caused by rupture of a giant aneurysm in which selective transvenous embolization via the pterygoid plexus was performed. OBSERVATIONS: An 81-year-old man presented with headache and various progressive cranial nerve symptoms due to a direct carotid-cavernous fistula caused by a ruptured giant aneurysm. All the draining veins visualized on preoperative examination immediately before the treatment were occluded except for the pterygoid plexus. Therefore, the authors chose the dilated pterygoid plexus to approach the shunted pouch at the cavernous sinus and achieve shunt obliteration by selective embolization with coils and n-butyl cyanoacrylate. LESSONS: Careful study of the three-dimensional rotational images in the preoperative examination is important when considering the various approaches to surgery. The pterygoid plexus can be an effective venous approach route to reach the cavernous sinus area.

Angioarchitecture of the Normal Lateral Spinal Artery and Craniocervical Junction Arteriovenous Fistula Using Contrast-enhanced Cone-beam CT.

BACKGROUND AND PURPOSE: The lateral spinal artery (LSA) perfuses the dorsolateral part of the spinal cord at the craniocervical junction (CCJ). We analyzed the angioarchitecture of the normal LSA and CCJ arteriovenous fistula (AVF). METHODS: The first study included 26 patients with a cerebral aneurysm of the posterior circulation. Using slab maximum intensity projection (MIP) images from three-dimensional rotational angiography (3D-RA) and contrast-enhanced cone-beam CT (CE-CBCT), we analyzed the origin of the LSA, its anastomosis with the posterior inferior cerebellar artery (PICA), the point where it reaches the spinal cord, and the visualized range. In the second study, we analyzed the angioarchitecture and treatment results of 7 CCJAVF lesions treated in our department between 2016 and 2021. RESULTS: We visualized the normal LSA for all patients. In 23 patients with an intradural origin PICA, all LSAs originated from the C1 or C2 radicular artery, and 8 patients had an anastomosis with the PICA. In three patients with a C1 level origin PICA, all LSAs originated from the PICA. All LSAs reached the dorsolateral part of the spinal cord. The mean visualized range of the LSA was 27.4 mm. The LSA was involved in five of seven CCJAVF lesions (71%). There was one lesion with a spinal infarction after LSA embolization. Other lesions were treated by direct interruption of the AVF, and the ASA and LSA were preserved. CONCLUSION: This is the first report that visualized the LSA's normal anatomy using slab MIP images from 3D-RA and CE-CBCT. Knowledge of LSA anatomy is critical to avoid complications during the treatment of CCJAVF.

Treatment outcome of coil embolization for distal anterior cerebral artery aneurysms: A single-center experience.

OBJECTIVE: In recent years, endovascular treatment has become the treatment of choice for distal anterior cerebral artery (DACA) aneurysms. In this study, we report the outcomes of coil embolization for DACA aneurysms. METHODS: Eighteen DACA aneurysms in 16 patients treated with endovascular treatment between January 2010 and December 2020 were included in this study. We retrospectively analyzed patient characteristics, data on aneurysms, the reason for the selection of endovascular treatment, treatment technique, and treatment outcomes. RESULTS: There were 18 procedures in 16 patients. The average age was 65.7 years and 56% of patients were male. The average diameter of the dome was 5.5 mm, and the location of aneurysm was A3 in 83% and A4 in 17%. We mainly selected endovascular treatment for patients with a past history of craniotomy and head trauma, or with systemic comorbidities. The technical success rate was 94%, and adequate obliteration immediately after treatment was achieved in 72%. There were no symptomatic periprocedural complications. The retreatment rate was 11.1%. CONCLUSION: Coil embolization for DACA aneurysms yielded good treatment outcomes. Endovascular treatment for DACA aneurysms will become more common with advances in endovascular devices and the establishment of stable perioperative antiplatelet therapy.

A case of delayed foreshortening and disconnection of pipeline embolization device detected by chronological cone-beam computed tomography fusion image.

OBJECTIVE: The morphological changes of the pipeline embolization device (PED; Medtronic, Minneapolis, MN, USA), such as delayed migration or foreshortening, can relate to the incomplete occlusion of aneurysms. CASE PRESENTATION: A 30-year-old man with a giant cavernous carotid artery aneurysm was treated with two PEDs using the overlapping technique. Six months after treatment, follow-up angiography showed morphological changes of the PEDs and residual flow into the aneurysm. Chronological cone-beam computed tomography fusion imaging clearly revealed the dynamic foreshortening of the first PED and the disconnection of both PEDs, so we decided to implant an additional PED. CONCLUSION: This case illustrates that a three-dimensional understanding can be useful for assessing the cause of treatment failure or recurrence.

A New Method of Intracranial Aneurysm Modeling for Stereolithography Apparatus 3D Printer: The "Wall-Carving Technique" Using Digital Imaging and Communications in Medicine Data.

OBJECTIVE: To assess the ability of the "wall-carving (WC) image technique", which uses vascular images from 3-dimensional digital subtraction angiograms (3DDSAs). Also, to verify the accuracy of the resulting 3D-printed hollow models of intracranial aneurysms. METHODS: The 3DDSA data from 9 aneurysms were processed to obtain volumetric models suitable for the stereolithography apparatus. The resulting models were filled with iodinated contrast media. 3D rotational angiography of the models was carried out, and the aneurysm geometry was compared with the original patient data. The accuracy of the 3D-printed hollow models' sizes and shapes was evaluated using the nonparametric Wilcoxon signed-rank test and the Dice coefficient index. RESULTS: The aneurysm volumes ranged from 34.1 to 4609.8 mm3 (maximum diameters 5.1-30.1 mm), and no statistically significant differences were noted between the patient data and the 3D-printed models (P = 0.4). Shape analysis of the aneurysms and related arteries indicated a high level of accuracy (Dice coefficient index value: 88.7%-97.3%; mean ± SD: 93.6% ± 2.5%). The vessel wall thickness of the 3D-printed hollow models was 0.4 mm for the parent and 0.2 mm for small branches and aneurysms, almost the same as the patient data. CONCLUSIONS: The WC technique, which involves volume rendering of 3DDSAs, can provide a detailed description of the contrast enhancement of intracranial vessels and aneurysms at arbitrary depths. These models can provide precise anatomic information and be used for simulations of endovascular treatment.

An Evaluation of the Safety and Feasibility of Adenosine-assisted Clipping Surgery for Unruptured Cerebral Aneurysms: Study Protocol.

The effectiveness of adenosine-induced flow arrest in surgical clipping for the cerebral aneurysms with difficulties in temporary clip placement to the proximal main trunk has been reported. This is the first clinical trial to evaluate the safety and feasibility of adenosine-assisted clipping surgery for unruptured cerebral aneurysms (UCAs) in Japan. The inclusion criteria are as follows: patients over 20 years old, patients who agree to be enrolled in this study after providing informed consent, patients who undergo clipping surgery for UCA in our institute, and patients in whom the surgeons (T.H. or I.D.) judge that decompression of the aneurysm is effective. The primary endpoint is a modified Rankin Scale (mRS) score 30 days after surgery. We plan to enroll 10 patients in this study. The original protocol of adenosine administration was established in this trial. Herein, we present the study protocol.

Choroid Plexus Hyperplasia with Intractable Ascites and a Resulting Communicating Hydrocele following Shunt Operation for Hydrocephalus.

Choroid plexus hyperplasia/papilloma and resulting hyperproduction of cerebrospinal fluid is a rare cause of hydrocephalus. In these patients, intractable ascites can occur after a ventriculoperitoneal (VP) shunting operation. However, shunt-related hydrocele is a rare complication of VP shunting. Previous reports have indicated catheter-tip migration to the scrotum as a cause of hydrocele. Here, we present the first documented case of choroid plexus hyperplasia that led to intractable ascites after shunting and a resulting hydrocele without catheter-tip migration into the scrotum.

Elevated Serum Fibrinogen Degradation Products on Admission Is a Novel Predictive Factor for Recurrence of Chronic Subdural Hematoma.

BACKGROUND: Previous studies reported an association of hematologic parameters, including white blood cells, neutrophil, eosinophils, or coagulation-related factors, with prognosis in cerebrovascular disorders. However, an association of recurrence rate with serum coagulation-related factors (e.g., D-dimer or fibrinogen degradation products [FDP]) in chronic subdural hematoma (CSDH) is unclear. METHODS: Ninety-two patients who experienced first-time CSDH treated with burr-hole hematoma evacuation were included in this study. Laboratory data on admission were used to divide patients into 2 groups: serum FDP >5 µg/mL or FDP ≤5 µg/mL (within normal range), based on the reference range of our institute. We retrospectively compared the recurrence rate of CSDH within 90 days after the first operation between these groups. Statistical significance was accepted at P < 0.05. RESULTS: Patients with an FDP greater than 5 µg/mL showed a significantly increased recurrence rate compared with those with a normal FDP (≤5 µg/mL; 27.3% vs. 10.2%, respectively; P = 0.03). Patients with an FDP greater than 5 µg/mL also showed a significantly higher recurrence rate within 30 days after the operation (15.2% vs. 3.4%, respectively; P = 0.04), but no difference in the recurrence rate at 31-90 days after the operation (12.1% vs. 6.8%, respectively; P = 0.38). In multivariable analysis, monolayer hematoma (odds ratio, 7.61; P = 0.003) and an FDP >5 µg/mL (odds ratio, 5.04; P = 0.01) were independent predictive factors for recurrence within 90 days. CONCLUSIONS: Elevated serum FDP on admission is a novel predictive factor for the recurrence of CSDH. These patients require careful follow-up, and recurrence within 30 days after the first operation should be considered.

Primary Central Nervous System Hodgkin Lymphoma-Like Posttransplant Lymphoproliferative Disorder.

BACKGROUND: Posttransplant lymphoproliferative disorder (PTLD) is a rare condition occurring after organ transplantation. PTLD comprises 4 subtypes, of which Hodgkin lymphoma (HL) type and HL-like type (currently included in polymorphic type) account for only about 1%-3% of cases. Primary central nervous system PTLD is also rare; most cases are Epstein-Barr virus-positive, B-cell PTLD. To our knowledge, no case of HL-like PTLD has been documented. CASE DESCRIPTION: A 43-year-old woman who underwent kidney transplantation for IgA nephropathy 14 years previously presented to the emergency department with seizure. Gadolinium-enhanced T1-weighted magnetic resonance imaging showed a ring-enhancing mass in the left temporal lobe. Gross total removal of the tumor was performed, and pathologic examination revealed findings consistent with HL-like PTLD. The patient's immunosuppressants were subsequently reduced, and she received postoperative systemic therapy with rituximab and radiation therapy. Follow-up magnetic resonance imaging showed no signs of relapse. CONCLUSIONS: This represents an extremely rare case of a patient with HL-like PTLD occurring as a primary central nervous system lesion.

Adult-Onset Hemorrhagic Quasi-Moyamoya Disease with Unilateral Steno-occlusive Lesion in a Patient with Neurofibromatosis Type 1.

BACKGROUND: Quasi-moyamoya disease is a condition that occurs in association with a specific underlying condition or disease such as atherosclerotic disease or neurofibromatosis type 1 (NF1). Pediatric cases are frequently reported, and an ischemic and bilateral presentation is more common than a hemorrhagic and unilateral presentation. CLINICAL PRESENTATION: A 39-year-old woman previously diagnosed with NF1 presented to our department with nausea and left hemiparesis. She was diagnosed with right temporal intracerebral hemorrhage by initial computed tomography. Subsequent angiography showed an occlusion of the terminal portion of the right internal carotid artery, and magnetic resonance imaging showed multiple flow voids in the right basal ganglia, suggesting quasi-moyamoya disease. The hematoma was surgically removed, and her neurological condition improved after the operation. CONCLUSIONS: This is the first reported case of quasi-moyamoya disease with a rare combination of characteristics, including an adult-onset, hemorrhagic presentation and a unilateral lesion in a patient previously diagnosed with NF1.

Peritoneal catheter knot formation in ventriculoperitoneal shunting: an intraoperative artificial phenomenon?

BACKGROUND: Peritoneal catheter knot formation is a rare complication associated with ventriculoperitoneal shunting. In most reports, the knot formation was also considered to be the cause of shunt malfunction. DISCUSSION: In this study, we demonstrate the possible misinterpretation of peritoneal catheter knot formation in ventriculoperitoneal shunting. We found a knot in the peritoneal catheter intraoperatively, while no knot was noted on the abdominal X-ray taken 1 day prior to the operation. Our findings indicate that the knot had actually formed intraoperatively. This case suggests that we should not immediately conclude that a knot is the cause of shunt malfunction in such an operation.

Hypertensive Cerebral Hemorrhage in a Patient with Turner Syndrome Caused by Deletion in the Short Arm of the X Chromosome.

Turner syndrome is a chromosomal disorder usually caused by complete deletion of an X chromosome, with deletion in the short arm of the X chromosome being a rare cause of the condition. Patients with Turner syndrome commonly develop hypertension, and associated vascular complications such as aortic dissection or cerebral hemorrhage have been reported. Cerebral hemorrhage in Turner syndrome is a rare complication, and only a few reports have been published. In these reports, all patients have XO karyotypes or a mosaic type as the cause of Turner syndrome, while no other Turner syndrome types have been documented. In this report, we present for the first time a patient with Turner syndrome caused by deletion in the short arm of the X chromosome who experienced hypertensive hemorrhage as a late complication.

Joint Capsule-Like Intracranial Osteochondroma Mimicking Cystic Meningioma.

This report provides the first representative images of an intracranial osteochondroma with a cystic component mimicking cystic meningioma. A 40-year-old male presented at our outpatient clinic with decreased sensation in his right upper extremity. Preoperative computed tomography showed a tumor with a cystic meningioma-like appearance and prominent calcifications. On magnetic resonance imaging, calcification of the lesion was suggested by the T2-weighted image; weak enhancement was seen on the T1-weighted image. Following surgical removal of the tumor, the pathologic examination showed findings consistent with osteochondroma. Cystic meningioma is a rare tumor with a cystic component. Intracranial osteochondroma is also a rare, benign tumor that can mimic meningioma when presenting in the dural convexity. Our report describes the joint capsule-like appearance of a convex cystic osteochondroma including a calcified cap, bonelike structure, and fluid-containing intracapsular space. The tumor was evaluated by imaging and pathologic studies.