Bailout using NBCA for incomplete onyx embolization of tentorial dural arteriovenous fistula.

Transarterial embolization using Onyx (Medtronic, Irvine, CA, USA) results in a high cure rate for complete obliteration of dural arteriovenous fistulas. However, incomplete obliteration occurs in some cases. Reports on the use of bailout therapy in such cases are limited. A 79-year-old man was diagnosed with Borden type III tentorial dural arteriovenous fistulas during a check-up for a headache. We first performed transarterial embolization with Onyx from a tentorial artery, but the fistula was not completely obliterated. We then performed an additional transarterial embolization with n-butyl-2-cyanoacrylate from the same artery in a single session, and the fistula was successfully bailed out, resulting in complete obliteration. Combining different liquid embolic materials, Onyx and n-butyl-2-cyanoacrylate, is an effective strategy for achieving complete obliteration in incomplete transarterial embolization treatment of dural arteriovenous fistulas.

Innovative use of a stent retriever for temporary revascularization in acute internal carotid artery dissection.

Internal carotid artery dissection is rare but can be a cause of stroke in young people. In a case of revascularization for stroke associated with internal carotid artery dissection, we initially used a stent retriever for thrombectomy. Since an appropriately-sized stent for permanent treatment was not available, we innovatively maintained temporary revascularization with the stent retriever for 90 minutes. Here we demonstrate the adaptability of the stent retriever for emergency care. A 49-year-old man suddenly developed severe right hemiplegia and aphasia. Magnetic resonance imaging showed occlusion of a left internal carotid artery with moderate ischemic changes in the left hemisphere cortex. Angiography showed dissection of the left internal carotid artery at the cervical level and secondary thrombus formation extending into the left middle cerebral artery. We initially attempted thrombectomy with a stent retriever and achieved successful reperfusion in the middle cerebral artery. An appropriately-sized stent was not available in the hospital at that time. During the 90-minute wait, the stent retriever was kept in place and temporary angioplasty was performed in the internal carotid artery dissection to maintain blood flow. Eventually, the stent was delivered and permanent revascularization was achieved. While there is no standard treatment for arterial dissection, endovascular strategies like stenting have been demonstrated to be beneficial. The innovative use of stent retrievers for temporary angioplasty of dissected lesions underscores their efficacy in swift deployment and maintenance of uninterrupted blood flow, particularly during emergency thrombectomy.

Predicting the O'Kelly-Marotta scale score after flow-diverter stent placement using silent MRA.

PURPOSE: Flow-diverter (FD) stents were developed to treat aneurysms that are difficult to treat with conventional coiling or surgery. This study aimed to compare usefulness of Silent MRA and TOF (time of flight) -MRA in patients with aneurysms after FD placement. MATERIALS AND METHODS: We retrospectively collected images from 22 patients with 23 internal carotid artery aneurysms treated with FD. Two radiologists conducted MRA and DSA experiments. In the first reading experiment, the radiologists evaluated the aneurysm filling by employing Silent MRA and TOF-MRA and utilizing the modified O'Kelly-Marotta (OKM) scale, a four-class classification system for aneurysms after FD placement. We then calculated the agreement between the modified OKM scale on MRA and the original OKM scale on DSA. In the second reading experiment, the radiologists rated blood flow within the FD using a five-point scale. RESULTS: The weighted kappa value of the OKM scale between DSA and TOF-MRA was 0.436 (moderate agreement), and that between DSA and Silent MRA was 0.943 (almost perfect agreement). The accuracies for the four-class classification were 0.435 and 0.870 for TOF-MRA and Silent MRA, respectively. The mean score of blood flow within FD for TOF-MRA was 2.43 ± 0.90 and that for Silent MRA was 3.04 ± 1.02 (P < 0.001). CONCLUSION: Silent MRA showed a higher degree of agreement than TOF-MRA in aneurysm filling with DSA. In addition, Silent MRA was significantly superior to TOF-MRA in depicting blood flow within the FD. Therefore, Silent MRA is clinically useful for the follow-up of patients after FD placement.

Potential of GSPT1 as a novel target for glioblastoma therapy.

Glioblastoma is the most common malignant brain tumor in adults, the survival rate of which has not significantly improved over the past three decades. Therefore, there is an urgent need to develop novel treatment modalities. We previously reported that G1 to S phase transition 1 (GSPT1) depletion induces delayed cell cycle in primary astrocytes. Herein, we examined the potential of GSPT1 as a novel target for glioblastoma therapy. CC-885, a cereblon modulator that degrades GSPT1 by bridging GSPT1 to the CRL4 E3 ubiquitin ligase complex, was administered to nude mice with transplanted brain tumors of U87 glioblastoma cells. The survival period was significantly longer in CC-885 treated mice than in control mice. Furthermore, we generated GSPT1-knockout (KO) U87 cells and GSPT1-KO U87 cells with stable overexpression of FLAG-tagged GSPT1 (Rescued GSPT1-KO). Mice with transplanted GSPT1-KO U87 cells and Rescued GSPT1-KO U87 cells showed significantly longer and similar survival periods, respectively, as those with wild-type (WT) U87 cells. GSPT1-KO U87 cells showed enhanced apoptosis, detected by cleaved PARP1, compared to WT U87 cells. Brain tumors with transplantation of GSPT1-KO U87 cells also showed enhanced apoptosis compared to those with transplantation of WT and Rescued GSPT1-KO U87 cells. GSPT1 expression was confirmed in patients with glioblastoma. However, the clinical study using 87 glioblastoma samples showed that GSPT1 mRNA levels were not associated with overall survival. Taken together, we propose that GSPT1 is an essential protein for glioblastoma growth, but not its malignant characteristics, and that GSPT1 is a potential target for developing glioblastoma therapeutics.

Acute morphological changes of impending rupture of vertebral artery dissection: clinical management of symptomatic but unruptured vertebral artery dissection. Illustrative case.

BACKGROUND: The reported actual risk of rupture for vertebral artery dissection (VAD) in patients presenting with headache is very low, ranging from 0.4% to 1.0%. The authors report a case in which the dissection site dilated rapidly within several hours after the dissection occurred resulting in subarachnoid hemorrhage (SAH). OBSERVATIONS: A 49-year-old healthy man who had participated in a marathon noticed a headache while running. Magnetic resonance imaging (MRI) performed 2 days later revealed no findings suspicious for right VAD, but a string sign was observed in the left side, suggesting left VAD. Three hours following MRI, he developed severe headaches and became unconscious at home, prompting emergency services to rush him to the hospital. A computed tomography scan showed diffuse SAH and a rapidly enlarged aneurysmal dilatation in the right vertebral artery. He underwent endovascular internal trapping to prevent rebleeding. He was discharged without any neurological symptoms. No recurrence or new dissection occurred after 2 years of follow-up. LESSONS: Even in the absence of typical imaging findings, strict management, such as blood pressure control, is required when clinical findings strongly suggest VAD, and differentiation of VAD from primary headache is important. https://thejns.org/doi/10.3171/CASE24202.

Predicting impaired cerebrovascular reactivity and risk of hyperperfusion syndrome in carotid artery stenosis using BeamSAT magnetic resonance imaging.

Pencil-beam presaturation (BeamSAT) magnetic resonance imaging (MRI) produces selective magnetic resonance angiography (MRA) images of specific arteries, including the unilateral internal carotid artery (ICA-selective MRA) or vertebral artery (VA-selective MRA). We evaluate the influence of flow pattern, visualized using BeamSAT MRI, on preoperative cerebral hemodynamic status and postoperative hyperperfusion syndrome (HPS). Patients undergoing carotid artery stenting or carotid endarterectomy were categorized into two groups to evaluate flow pattern. Patients with neither crossflow on BeamSAT MRI nor mismatch in middle cerebral artery (MCA) signal intensity between ICA-selective and conventional MRA were classified into Group I, comprising 29 patients. Group II included all other patients comprising 19 patients, who were suspected of experiencing changes in intracranial flow patterns. Cerebral blood flow and cerebrovascular reactivity (CVR) were assessed using single-photon emission computed tomography, and potential HPS symptoms were retrospectively assessed by chart review. Preoperative ipsilateral CVR was significantly lower in Group II than in Group I (18.0% ± 20.0% vs. 48.3% ± 19.5%; P < 0.0001). Group II showed significantly impaired CVR (odds ratio 17.7, 95% confidence interval 1.82-171; P = 0.013) in multivariate analysis. The partial areas under the curve of the BeamSAT logistic model (0.843) were significantly larger than those of the conventional logistic model (0.626) over the range of high sensitivity (0.6-1) (P = 0.04). The incidence of postoperative HPS symptoms was significantly higher in Group II than in Group I (8/19 vs. 1/29; P = 0.001). BeamSAT MRI may be a valuable and non-invasive tool for assessing cerebral hemodynamics and predicting postoperative HPS.

Multiple Synchronous Spinal Dural Arteriovenous Fistulas: A Systematic Literature Review.

BACKGROUND AND OBJECTIVES: Spinal dural arteriovenous fistulas (SDAVFs) lead to progressive neurological decline with symptoms such as paraparesis, bowel and bladder dysfunction, and sensory disturbances because of impaired spinal cord venous drainage. This study aimed to systematically review the literature on multiple synchronous SDAVFs and present 2 cases from our institution. METHODS: A comprehensive search was performed to identify all published cases of multiple synchronous SDAVFs. Overall, 23 patients with multiple synchronous SDAVFs were identified, including 21 from 19 articles and 2 from this study. The clinical presentation, lesion location, radiographic features, surgical treatment, and outcomes were analyzed in each patient. RESULTS: All patients in this study were male, and the duration from symptom onset to diagnosis in many of these patients was longer than that previously reported. Previous studies suggested that multiple SDAVFs typically occurred within 3 or fewer vertebral levels. However, >50% of the examined patients had remote lesions separated by more than 3 vertebral levels. Patients with remote lesions had a significantly worse outcome (1/7 vs 8/11, 95% CI 0.001-0.998; P = .049). CONCLUSION: Accurately locating fistulas before spinal angiography is critical for managing multiple remote SDAVFs. Considering the possibility of multiple remote SDAVFs, careful interpretation of imaging findings is essential for an accurate diagnosis and appropriate treatment planning.

Next-Generation Exoscopic Surgery Featuring a Head-Mounted 3-Dimensional Display for Carotid Endarterectomy: 2-Dimensional Operative Video.

Recent advancements in medical equipment have led to the use of exoscopes in neurosurgery, thereby replacing conventional operating microscopes.1,2 These devices enable surgeons to work comfortably, even in situations requiring a tilted visual axis, and their effectiveness in carotid endarterectomy (CEA) for carotid artery stenosis has been reported.3,4 However, the placement of 3-dimensional (3D) monitoring devices is challenging.3,4 To address this issue, we present a case in which CEA was performed using ORBEYE with a 3D head-mounted display. This device allows continuous 3D observation of the surgical field on the preocular screen. Case: A 79-year-old man who had undergone chemoradiotherapy for left maxillary cancer 5 years earlier was referred to our department to undergo treatment for left internal carotid artery stenosis. Computed tomography angiography revealed severe left internal carotid artery stenosis with hypoechoic vulnerable plaques on carotid ultrasound. Carotid artery stenting was considered to be a better option than CEA. However, CEA yields better outcomes, especially in patients with vulnerable soft plaques.5 Left CEA was performed using ORBEYE with a 3D head-mounted display (HOGY Medical Co., Ltd.). The procedure was successfully performed under the observation of the head-mounted display, from skin incision to closure. Postoperatively, the patient had no neurological deficits but experienced transient hoarseness. Using an exoscope under the guidance of a head-mounted display represents a next-generation surgical technique that overcomes the limitations of traditional exoscopic surgery. The patient consented to the procedure, and the participants and any identifiable individuals consented to publication of his/her image. Our institutional review board approved this publication (#B230184).

Successful shrinkage of a recurrent partially thrombosed symptomatic large basilar tip aneurysm using a Target 3D Coil.

Background: Standalone coil embolization is often less effective for partially thrombosed intracerebral aneurysms (PTIA) because of the risk of frequent recurrence if the coil migrates into the thrombus. This report describes a case of PTIA at the basilar tip in which simple coil embolization using a Target 3D Coil resulted in sustained remission without recurrence during long-term follow-up. Case Description: The patient was a 63-year-old male who presented with right oculomotor nerve palsy after having undergone direct surgery for a basilar artery aneurysm 15 years earlier. Recurrence with partial thrombosis of the basilar artery aneurysm was diagnosed. Target 3D Coil embolization with frame construction in the aneurysmal sac was performed, resulting in the complete disappearance of the aneurysm and improvement of the oculomotor nerve palsy. Magnetic resonance imaging at five years postoperatively confirmed that the thrombus had completely disappeared, and there was no recurrence of the aneurysm. The closed loops in the Target 3D Coil may have contributed to the cohesive mass of coils remaining in the sac of the PTIA, potentially leading to healing. Conclusion: The characteristics of the Target 3D Coil may have prevented migration of the coil into the thrombus, potentially contributing to the successful resolution of the aneurysm.

A vertebrobasilar junction aneurysm successfully treated with a combination of surgical clipping and flow diverter placement based on the results of computational fluid dynamics analysis: illustrative case.

BACKGROUND: The treatment of vertebrobasilar junction (VBJ) aneurysms is challenging. Although flow diverters (FDs) are a possible treatment option, geometrical conditions hinder intervention. VBJ aneurysms possess dual inflow vessels from the bilateral vertebral arteries (VAs), one of which is ideally occluded prior to FD treatment. However, it remains unclear which VA should be occluded. OBSERVATIONS: A 75-year-old male with a growing VBJ complex aneurysm exhibiting invagination toward the brainstem and causing perifocal edema required intervention. Preoperative computational fluid dynamics (CFD) analysis demonstrated that left VA occlusion would result in more stagnant flow and less impingement of flow than right VA occlusion. According to the simulated strategy, surgical clipping of the left VA just proximal to the aneurysm was performed, followed by FD placement from the basilar artery trunk to the right VA. The patient demonstrated tolerance of the VA occlusion, and follow-up computed tomography angiography at 18 months after FD treatment confirmed the disappearance of the aneurysm. LESSONS: Preoperative flow dynamics simulations using CFD analysis can reveal an optimal treatment strategy involving a hybrid surgery that combines FD placement and direct surgical occlusion for a VBJ complex aneurysm.

Steerable microcatheter for distal access of a giant cavernous carotid artery aneurysm during treatment with Pipeline Embolization Device: A case report and review of the literature.

Background: In the treatment of giant cerebral aneurysms with flow-diverting stents, access to the distal parent artery is critical but occasionally challenging. This article provides our experience with a novel steerable microcatheter in such a situation, as well as a review of the literature. Case Description: A 73-year-old woman presented with right ptosis and external ophthalmoplegia. Magnetic resonance angiography revealed a giant right cavernous internal carotid artery aneurysm. Endovascular treatment was planned with flow diversion, but distal access was not possible using the standard technique. A 2.4-Fr steerable microcatheter, Leonis Mova Selective, was implemented, and by bending the catheter tip toward the distal parent artery, a guidewire could be guided distally. After the catheter exchange, two flow-diverting stents were deployed successfully. Conclusion: Steerable microcatheters may provide an option in treatment with flow-diverting stents for giant cerebral aneurysms where access to the distal parent artery is compromised.

Prevalence and Severity of Positional Posterior Plagiocephaly and Positional Posterior Brachycephaly in Children and Adolescents in Japan.

This study aimed to assess the prevalence, severity, and natural history of positional posterior plagiocephaly (PPP) and positional posterior brachycephaly in Japan. We conducted a cross-sectional study of pediatric patients, ranging from 0 to 15 years old, evaluated for head trauma with negative computed tomography (CT) findings. The cranial vault asymmetry index (CVAI) was calculated using CT images at the superior orbital rim. Asymmetry according to CVAI values was subcategorized as follows: mild (3.5%-7%), moderate (7%-12%), and severe (>12%). The results were analyzed according to different age groups: group 1, 2-23 months (54 patients); group 2, 2-6 years (123 patients); and group 3, 7-15 years (123 patients). Overall, 300 patients were included (109 [36.3%] girls and 191 [63.7%] boys). The overall prevalence of PPP in the 300 patients was 46.7% (140 patients). PPP prevalence decreased consistently with age group: group 1, 57.4%; group 2, 47.2%; and group 3, 41.5%. Severe asymmetry was seen in all age groups. The overall mean cephalic index (CI) was 85.2. Cephalic index scores decreased consistently with age: group 1, 87.4; group 2, 85.1; and group 3, 84.3. The prevalence of PPP in Japan was higher than that reported in other countries. Although there was an overall decrease in the prevalence and severity of PPP with increasing patient age, PPP does not necessarily resolve spontaneously in all children. Furthermore, severe asymmetry was seen across all age groups.

Stereotactic radiotherapy of radiation-induced meningioma previously irradiated retrobulbar for Graves' ophthalmopathy: A case report.

A 69-year-old woman was diagnosed with an asymptomatic intracranial tumor nine years ago and has been followed with annual MR imaging studies. Two years ago, the tumor had grown in size, requiring treatment. She experienced ophthalmopathy due to hyperthyroidism 27 years ago and was treated with 20 Gy in 10 fractions using parallel opposed beams to her bilateral posterior eyeballs, supplemented with steroid pulse therapy. The tumor originated in the medial aspect of the right sphenoid border and compressed the temporal lobe, while bone infiltration was observed, partially extending to the soft tissue outside the maxillary sinus. The tumor was removed by craniotomy. The pathological diagnosis was atypical meningioma (WHO grade II). Four months postsurgery, the resection cavity's tumor exhibited growth inclination, necessitating Gamma Knife radiosurgery. Radiation planning was executed at a marginal tumor dose of 30 Gy in 5 fractions. Since the optic nerve had been previously exposed to radiation, a plan was devised to minimize radiation exposure. The dose on the optic nerve was limited to 6.9 Gy in 5 fractions. She did not experience any visual or visual field disruptions postradiation. This is a case of radiation-induced meningioma resulting from radiation therapy for Graves' ophthalmopathy and is the first reported case of a grade II meningioma. The patient's condition calls for adjuvant radiation therapy following surgical removal. Accordingly, a radiation treatment plan that safeguards the optic nerve, which was previously exposed to radiation, was deemed indispensable.

Subclassification of Koos grade 4 vestibular schwannoma: insights into tumor morphology for predicting postoperative facial nerve function.

OBJECTIVE: Koos grade 4 vestibular schwannoma (KG4VS) is a large tumor that causes brainstem displacement and is generally considered a candidate for surgery. Few studies have examined the relationship between morphological differences in KG4VS other than tumor size and postoperative facial nerve function. The authors have developed a landmark-based subclassification of KG4VS that provides insights into the morphology of this tumor and can predict the risk of facial nerve injury during microsurgery. The aims of this study were to morphologically verify the validity of this subclassification and to clarify the relationship of the position of the center of the vestibular schwannoma within the cerebellopontine angle (CPA) cistern on preoperative MR images to postoperative facial nerve function in patients who underwent microsurgical resection of a vestibular schwannoma. METHODS: In this paper, the authors classified KG4VSs into two subtypes according to the position of the center of the KG4VS within the CPA cistern relative to the perpendicular bisector of the porus acusticus internus, which was the landmark for the subclassification. KG4VSs with ventral centers to the landmark were classified as type 4V, and those with dorsal centers as type 4D. The clinical impact of this subclassification on short- and long-term postoperative facial nerve function was analyzed. RESULTS: In this study, the authors retrospectively reviewed patients with vestibular schwannoma who were treated surgically via a retrosigmoid approach between January 2010 and March 2020. Of the 107 patients with KG4VS who met the inclusion criteria, 45 (42.1%) were classified as having type 4V (KG4VSs with centers ventral to the perpendicular bisector of the porous acusticus internus) and 62 (57.9%) as having type 4D (those with centers dorsal to the perpendicular bisector). Ventral extension to the perpendicular bisector of the porus acusticus internus was significantly greater in the type 4V group than in the type 4D group (p < 0.001), although there was no significant difference in the maximal ventrodorsal diameter. The rate of preservation of favorable facial nerve function (House-Brackmann grades I and II) was significantly lower in the type 4V group than in the type 4D group in terms of both short-term (46.7% vs 85.5%, p < 0.001) and long-term (82.9% vs 96.7%, p = 0.001) outcomes. Type 4V had a significantly negative impact on short-term (OR 7.67, 95% CI 2.90-20.3; p < 0.001) and long-term (OR 6.05, 95% CI 1.04-35.0; p = 0.045) facial nerve function after surgery when age, tumor size, and presence of a fundal fluid cap were taken into account. CONCLUSIONS: The authors have delineated two different morphological subtypes of KG4VS. This subclassification could predict short- and long-term facial nerve function after microsurgical resection of KG4VS via the retrosigmoid approach. The risk of postoperative facial palsy when attempting total resection is greater for type 4V than for type 4D. This classification into types 4V and 4D could help to predict the risk of facial nerve injury and generate more individualized surgical strategies for KG4VSs with better facial nerve outcomes.

Rupture Risk Factors and Strategies for Unruptured Distal Anterior Cerebral Artery Aneurysms.

BACKGROUND: Distal anterior cerebral artery (dACA) aneurysms are rare. Ruptured dACA aneurysms typically present with subarachnoid hemorrhage in conjunction with intracerebral hematoma and cause neurological deterioration. This study aimed to determine their risk of rupture and examine associated factors. METHODS: We retrospectively analyzed patients with dACA aneurysms to compare patient and aneurysm characteristics between ruptured and unruptured aneurysms. Clinical outcome was used the modified Rankin scale. Univariate analyses were performed to identify rupture risk factors. RESULTS: One hundred three patients with dACA aneurysms were examined (51 ruptured and 52 unruptured). The median aspect ratio of ruptured and unruptured aneurysms was 1.69 and 1.22, respectively (P < 0.01). The median maximum diameter of ruptured and unruptured aneurysms was 5.2 and 3.1 mm, respectively (P < 0.01). The median size ratio of ruptured and unruptured aneurysms was 3.32 and 2.17, respectively (P < 0.01). Maximum diameter was <5 mm in 45.2% of ruptured dACA aneurysms. dACA aneurysm, showing size ratio >2.4 and aspect ratio >1.4, had ruptured in 71.4% and 78.6%, respectively. We suggested that these are the threshold of size ratio and aspect ratio for rupture of dACA aneurysms. A total percentatge of 78.1% of aneurysms with aspect ratio >1.4 and size ratio >2.4 had ruptured. CONCLUSIONS: Distal anterior cerebral artery (dACA) aneurysms may rupture, even when small. We found a significant difference between ruptured and unruptured aneurysms with respect to maximum diameter, aspect ratio, and size ratio. Treatment for small aneurysms should be considered based on size ratio and aspect ratio, not just size.

Delayed facial palsy after resection of vestibular schwannoma: does it influence long-term facial nerve functional outcomes?

OBJECTIVE: Delayed facial palsy (DFP) is a common and unique complication after resection of vestibular schwannoma (VS). Few studies have focused on the clinical question of whether patients with DFP can be expected to have the same long-term prognosis in terms of facial nerve function as those without DFP based on their facial nerve function immediately postoperatively. This study aimed to clarify the clinical impact of DFP on the long-term functional status of the facial nerve after VS resection. METHODS: The authors retrospectively reviewed patients with sporadic VS who were treated surgically via a retrosigmoid approach between January 2002 and March 2020. DFP was defined as de novo deterioration of facial nerve function by a House-Brackmann (HB) grade ≥ I more than 72 hours postoperatively. The incidence of DFP after VS resection and its impact on long-term facial nerve function were analyzed. RESULTS: DFP developed in 38 (14.3%) of 266 patients who met the inclusion criteria. The median latency until DFP onset postoperatively was 8.5 days. When facial nerve function was normal immediately postoperatively, the rate of preservation of favorable facial nerve function (HB grade I or II) at 24 months postoperatively was 100% for all patients regardless of whether they developed DFP. In contrast, when facial nerve dysfunction was present immediately postoperatively, the rate of preservation of favorable facial nerve function at 24 months postoperatively was significantly lower in patients with DFP than in those without DFP (77.8% vs 100% in patients with HB grade II immediately postoperatively, p = 0.001; 50.0% vs 90.3% in those with HB grade III immediately postoperatively, p = 0.042). DFP development had a significantly negative impact on the long-term functional status of the facial nerve postoperatively when age, tumor size, and HB grade immediately postoperatively were taken into account (OR 0.04, 95% CI 0.01-0.20; p < 0.001). CONCLUSIONS: DFP can be a minor complication when normal facial nerve function is observed immediately after surgery. However, when facial nerve dysfunction is present immediately after surgery, even if mild, the long-term prognosis for facial nerve function is significantly worse in patients with DFP than in those without DFP.

Introducing next-generation transcranial surgery with the head-mounted 3D View Vision display in extracorporeal microsurgery: illustrative cases.

BACKGROUND: Exoscopy in neurosurgery offers various advantages, including increased freedom of the viewing axis while the surgeon maintains a comfortable upright position. However, the optimal monitor positioning to avoid interference with surgical manipulation remains unresolved. Herein, the authors describe two cases in which a three-dimensional head-mounted display (3D-HMD) was introduced into a transcranial neurosurgical procedure using an exoscope. OBSERVATIONS: Case 1 was a 50-year-old man who presented with recurrent epistaxis and was diagnosed with an olfactory neuroblastoma that extended from the nasal cavity to the anterior cranial base and infiltrated the right anterior cranial fossa. Case 2 was a 65-year-old man who presented with epistaxis and was diagnosed with a left-sided olfactory neuroblastoma. In both cases, en bloc tumor resection was successfully performed via a simultaneous exoscopic transcranial approach using a 3D-HMD and an endoscopic endonasal approach, eliminating the need to watch a large monitor beside the patient. LESSONS: This is the first report of using a 3D-HMD in transcranial surgery. The 3D-HMD effectively addressed issues with the field of vision and concentration while preserving the effectiveness of traditional microscopic and exoscopic procedures when observed on a 3D monitor. Combining the 3D-HMD with an exoscope holds the potential to become a next-generation surgical approach.

Combined transarterial and transvenous embolization of anterior cranial fossa dural arteriovenous fistula.

Background: Excessive glue injection into the drainage vein in patients with dural arteriovenous fistula (dAVF) can result in venous obstruction. We performed transarterial embolization (TAE) combined with transvenous embolization (TVE) with coils to prevent the glue from migrating into the normal cortical veins. Case Description: A 57-year-old man was pointed out to have a Borden Type III anterior cranial fossa dAVF during a check-up for putaminal hemorrhage. Because a left frontal normal cortical vein drained into the pathological drainage vein, excessive glue injection into the drainage vein may have caused venous obstruction. We performed TVE with coils at the foot of the draining vein to prevent excessive migration of glue into the drainer, followed by TAE with glue. With this technique, complete obliteration of the shunt without venous ischemia was obtained. Conclusion: The combined treatment of TAE and TVE is effective in preventing venous ischemia caused by unintended migration of glue cast into the drainage vein.