Stroke events and risk factors in older patients with moyamoya disease.

BACKGROUND: We aimed to comprehensively analyze the epidemiology, natural history, stroke events and their risk factors, and the RNF213 p.Arg4810Lys variant in older patients with moyamoya disease (MMD). METHODS: We enrolled patients with MMD followed-up at our hospital between 2000 and 2023. Those who developed MMD at age ≥ 60 years or were diagnosed at a younger age and followed-up after age 60 years were included. Baseline characteristics, onset type, radiological features, and RNF213 p.Arg4810Lys variant status were investigated. RESULTS: Among 56 patients with 100 affected hemispheres, 62 were asymptomatic, 26 experienced ischemic onset, and 12 had hemorrhagic onset. A higher incidence of anterior choroidal artery (AchA) dilatation and lower proportion of favorable modified Rankin scale scores were detected in hemorrhagic onset, whereas greater prevalence of bypass surgery in ischemic onset. Of 76 asymptomatic hemispheres at the age of 60 years, subsequent stroke events occurred in 10 hemispheres, comprising eight hemorrhages and two ischemias. Risk factors for de novo hemorrhage in asymptomatic hemispheres included AchA dilatation and choroidal anastomosis. Comparison of the RNF213 p.Arg4810Lys variant status showed no significant differences in baseline characteristics, onset types, or imaging findings, except for a higher percentage of patients in the GA group with a family history of MMD. CONCLUSIONS: Hemorrhagic events were the most prevalent and prognostically deteriorating factors in older patients with MMD aged ≥60 years. AchA dilatation and choroidal anastomosis were predictors of de novo hemorrhage in asymptomatic nonsurgical hemispheres in older patients with MMD.

Association of Genetic Variants with Postoperative Donor Artery Development in Moyamoya Disease: RNF213 and Other Moyamoya Angiopathy-Related Gene Analysis.

Robust postoperative bypass development is a characteristic of moyamoya disease (MMD); however, genetic factors mediating this phenomenon remain incompletely understood. Therefore, we aimed to elucidate the relationship between postoperative donor artery development and genetic variants. We retrospectively enrolled 63 patients (79 hemispheres) who underwent combined revascularization surgery. Postoperative development of the superficial temporal artery (STA), middle meningeal artery, and deep temporal artery (DTA) was assessed using the caliber-change ratio determined from magnetic resonance angiography measurements. We analyzed RNF213 and 36 other moyamoya angiopathy-related genes by whole-exome sequencing and extracted rare or damaging variants. Thirty-five participants carried RNF213 p.Arg4810Lys (all heterozygotes), whereas 5 had RNF213 rare variants (RVs). p.Arg4810Lys was significantly associated with postoperative DTA development, while age at surgery, hypertension, and hyperlipidemia were inversely associated. Multiple regression analysis revealed that age and p.Arg4810Lys held statistical significance (P = 0.044, coefficient - 0.015, 95% confidence interval (CI) - 0.029 to 0.000 and P = 0.001, coefficient 0.670, 95% CI 0.269 to 1.072, respectively). Those with RNF213 RV without p.Arg4810Lys exhibited a significant trend toward poor DTA development (P = 0.001). Hypertension demonstrated a significant positive association with STA development, which remained significant even after multiple regression analysis (P = 0.001, coefficient 0.303, 95% CI 0.123 to 0.482). Following Bonferroni correction for multiple comparisons, targeted analyses of RNF213 and 36 moyamoya angiopathy-related genes showed a significant association of only RNF213 p.Arg4810Lys with favorable DTA development (P = 0.001). A comprehensive analysis of RNF213, considering both p.Arg4810Lys and RVs, may provide a clearer prediction of postoperative DTA development.

Suzuki Stage VI Unilateral Moyamoya Disease Presenting With Massive Intraventricular Hemorrhage.

Moyamoya disease (MMD) is characterized by stenosis of the terminal portion of the internal carotid artery (ICA) and the development of collateral vessels. In late Suzuki stage MMD, ICA almost disappears, and the moyamoya vessels gradually regress. We report a case of late Suzuki stage unilateral MMD presenting with intraventricular hemorrhage. A 76-year-old woman who had previously been diagnosed with right ICA occlusive disease was referred to our hospital due to impaired consciousness. Radiological evaluation revealed massive intraventricular hemorrhage. After endoscopic hematoma removal, digital subtraction angiography (DSA) was performed to examine the vascular anatomy, which revealed numerous basal moyamoya vessels originating from the posterior cerebral artery. Three-dimensional rotational angiography identified a choroidal anastomosis originating from the posterior choroidal artery as the hemorrhage source. The patient had an RNF213 p.Arg4810Lys heterozygous variant in the germline. Based on the DSA findings, MMD was diagnosed, and the patient was transferred to a rehabilitation hospital with good postoperative consciousness. In conclusion, patients diagnosed with ICA occlusive disease may have late Suzuki stage MMD, potentially leading to major hemorrhage; therefore, antithrombotic medications should be administered with caution. In diagnosing ICA occlusive disease, the assessment of periventricular anastomosis should be considered, taking into account the possibility of MMD.

Hypertensive disorders of pregnancy in moyamoya disease: A single institution experience.

OBJECTIVE: The characteristics of pregnancy and delivery in patients with moyamoya disease (MMD) remain unclear. We retrospectively investigated perinatal outcomes in patients with MMD to evaluate the risks associated to this condition. MATERIALS AND METHODS: Clinical data of women with MMD who delivered at the University of Tokyo Hospital between 2000 and 2021 were collected. Maternal characteristics including genetic data, obstetric complications, method of delivery and anesthesia, neonatal outcomes, neurological events during pregnancy, delivery, and postpartum course, were reviewed. RESULTS: Thirteen pregnancies with MMD were identified. The median maternal age was 30 years. The initial clinical symptoms were identified as transient ischemic attack, infarction, and headache. Eight patients had a history of bypass surgery. The median gestational age at delivery was 37 weeks. DNA samples were collected from five patients, responsible for six pregnancies. Of these six cases, five had the RNF213 c.14429G > A (p.Arg4810Lys) heterozygous variant. Of the 13 pregnancies, seven had hypertensive disorder of pregnancy (HDP). Additionally, three of five pregnancy cases with RNF213 p.Arg4810Lys heterozygous variant presented with HDP. Nine patients underwent cesarean section, and four delivered vaginally with epidural anesthesia. One case of ischemic stroke was confirmed during the postpartum period. Regarding newborns, neither Apgar scores lower than 7 nor neonatal intensive care unit admissions were reported. CONCLUSIONS: This study suggests that the frequency of HDP is higher in patients with MMD compared to those with normal pregnancies. Strict blood pressure control should be performed in patients with MMD during pregnancy and postpartum period.

Bypass Surgery for Adult-Onset Hemorrhagic Moyamoya Disease: Analysis Classified by Site of Initial Bleeding.

OBJECTIVE: Prevention of rebleeding events is crucial for patients with hemorrhagic moyamoya disease (MMD), as these increase the risk of mortality. Bypass surgery is effective in preventing subsequent hemorrhage, particularly in patients with posterior hemorrhage, but its efficacy in those with anterior hemorrhage remains unclear. We analyzed the effects of surgical intervention, stroke risk factors, and radiological features on rebleeding events. METHODS: Patients with hemorrhagic-onset MMD who were followed at our institution between 2000 and 2022 were included (41 adult patients, 45 hemispheres). Baseline characteristics and radiological features (anterior or posterior hemorrhagic site, Suzuki grade, posterior cerebral artery involvement, and periventricular anastomosis) were thoroughly reviewed. RESULTS: Of the 45 hemispheres, hemorrhage developed in 9 (20%) hemispheres, with a median duration until rebleeding of 38 (range: 1-44) months. Rebleeding rates were significantly lower in the surgical group than in the nonsurgical group (odds ratio: 0.09; 95% confidence interval [CI]: 0.01-0.79; P = 0.011), and Kaplan-Meier analysis revealed a significantly longer interval between bleeding events in the surgical group (1.3%/y vs. 5.3%/y; P = 0.002), especially in the anterior hemorrhage group (1.3%/y vs. 5.1%/y; P = 0.019). The hazard ratio of surgical intervention for rebleeding with initial anterior hemorrhage was 0.11 (95% CI: 0.01-0.98; P = 0.048). In the nonsurgical group, the presence of hypertension shortened the time to subsequent hemorrhage (P = 0.004). CONCLUSIONS: Surgical intervention may decrease the risk of rebleeding in hemorrhagic onset MMD patients, even in those presenting with anterior hemorrhage. Hypertension was a significant risk factor for rebleeding in nonsurgical patients.

Cerebrovascular Events During Treatment for Systemic Malignant Tumors in Patients with Moyamoya Disease.

OBJECTIVE: With the increasing incidence of malignancies, the importance of cancer-associated stroke is emphasized. Although moyamoya disease is a leading cause of stroke, no reports have documented cancer-associated stroke in patients with this condition. We aimed to investigate cerebrovascular events during malignancy treatments in patients with moyamoya disease. METHODS: A total of 405 patients with moyamoya disease who visited our hospital between January 2000 and March 2022 were retrospectively examined. We evaluated the management of moyamoya disease, presence of the ring finger protein 213 p.Arg4810Lys variant, treatments for malignant tumors, presence of cerebrovascular events during treatment, and follow-up periods and outcomes. RESULTS: Among the 405 patients, 17 patients with moyamoya disease (4.2%) were diagnosed with malignancies. Among patients aged 60 years and over, 7 out of 67 (10.4%) had malignancies. Of the 17 patients, 11 (64.7%) were symptomatic, and 7 (41.2%) had revascularization surgery. 9 patients were treated with oral antiplatelet drugs. There was no significant difference between the groups with and without malignancy regarding the presence of the ring finger protein 213 p.Arg4810Lys variant (80.0% vs. 62.7%, P = 0.33). All patients underwent surgical treatment, and 7 (41.2%) received chemotherapy. One death due to tumor progression was reported. No cerebrovascular event was observed during malignancy treatments and follow-up periods, which had a mean duration of 6 years. CONCLUSIONS: In our cohort, malignancy treatments in patients with moyamoya disease were safely conducted without cerebrovascular events. However, it is advisable to avoid hypotension, dehydration, hyperventilation, and long-term discontinuation of antiplatelet drugs during the treatment of malignant tumors.

RNF213 p.Arg4810Lys Wild Type is Associated with De Novo Hemorrhage in Asymptomatic Hemispheres with Moyamoya Disease.

Clinical implications of RNF213 genetic variants, other than p.Arg4810Lys, in moyamoya disease (MMD), remain unclear. This study aimed to investigate the association of RNF213 variants with clinical phenotypes in MMD. This retrospective cohort study collected data regarding the clinical characteristics of 139 patients with MMD and evaluated the angioarchitectures of 253 hemispheres using digital subtraction angiography at diagnosis. All RNF213 exons were sequenced, and the associations of clinical characteristics and angiographical findings with p.Arg4810Lys, p.Ala4399Thr, and other rare variants (RVs) were examined. Among 139 patients, 100 (71.9%) had p.Arg4810Lys heterozygote (GA) and 39 (28.1%) had the wild type (GG). Fourteen RVs were identified and detetcted in 15/139 (10.8%) patients, and p.Ala4399Thr was detected in 17/139 (12.2%) patients. Hemispheres with GG and p.Ala4399Thr presented with significantly less ischemic events and more hemorrhagic events at diagnosis (p = 0.001 and p = 0.028, respectively). In asymptomatic hemispheres, those with GG were more susceptible to de novo hemorrhage than those with GA (adjusted hazard ratio [aHR] 5.36) with an increased risk when accompanied by p.Ala4399Thr or RVs (aHR 15.22 and 16.60, respectively). Within the choroidal anastomosis-positive hemispheres, GG exhibited a higher incidence of de novo hemorrhage than GA (p = 0.004). The GG of p. Arg4810Lys was a risk factor for de novo hemorrhage in asymptomatic MMD hemispheres. This risk increased with certain other variants and is observed in choroidal anastomosis-positive hemispheres. A comprehensive evaluation of RNF213 variants and angioarchitectures is essential for predicting the phenotype of asymptomatic hemispheres in MMD.

Sequential Middle Meningeal Artery Embolization after Burr Hole Surgery for Recurrent Chronic Subdural Hematoma.

Middle meningeal artery embolization (MMAE) for chronic subdural hematoma (CSDH) is a novel, minimally invasive treatment. The indications and treatment practices for MMAE are variable and remain controversial. This study aimed to evaluate a strategy involving sequential MMAE after burr hole surgery for treating recurrent CSDH. We performed a retrospective analysis of data from consecutive patients who had undergone MMAE using liquid embolic agents within approximately 2 weeks after burr hole surgery for recurrent CSDH from September 2020 to March 2022. We analyzed patient characteristics, procedural details, CSDH recurrence after MMAE, surgical rescue, and complications. Six of the nine patients who underwent MMAE for CSDH recurrence were male, and the median age was 85 (range, 70-94) years. Five of the nine patients were being administered antithrombotic agents. The median duration between the burr hole surgery and MMAE procedure was 10 (range, 3-25) days. Anterior and posterior convexity branches were targeted for embolization using low-concentration N-butyl cyanoacrylate (NBCA), and the abnormal vascular networks with a cotton wool appearance disappeared after embolization in all cases. The NBCA distribution was observed by high-resolution computed tomography during the procedure; in three of nine cases, the NBCA penetrated not only the MMA but also the inner membrane. No recurrence, surgical rescue, or complications were observed in any patient during the median follow-up period of 3 months. As a minimally invasive treatment for recurrent CSDH, sequential MMAE after burr hole surgery may be a safe and effective option for preventing recurrence.

Extradural Middle Fossa and Transcavernous Approach for Resection of Trigeminal Neurinoma at Lateral Cavernous Sinus.

We present a 52-year-old male case of right trigeminal neurinoma at lateral cavernous sinus. The tumor was 40 mm in maximum diameter, obviously compressed temporal lobe and encased internal carotid artery. Extradural middle fossa and transcavernous approach was applied and the tumor was resected via Parkinson's triangle. This approach enabled safe and effective tumor resection, sufficient visualization, and operative field ( Figs. 1 and 2 ). We performed dissection of the tumor from trigeminal nerve, tentorium, and middle fossa and resect the tumor around internal carotid artery sufficiently. Postoperative course was good without any new neurological deficit. This surgical method is considered safe and effective for the resection of the tumor at lateral cavernous sinus. The link to the video can be found at: https://youtu.be/2ekuILIgEuo.

Evaluation of Middle Cerebral Artery Symmetry: A Pilot Study for Clinical Application in Mechanical Thrombectomy.

BACKGROUND: Endovascular mechanical thrombectomy (MT) has now evolved to become the standard treatment for acute ischemic stroke due to large vessel occlusion. Arterial perforation is a potential complication of MT, and the risk of this event during blind crossing the occlusion site has been elucidated. The intracranial arterial system shows morphological structural symmetry, so we investigated the utility of the bilateral symmetry of the proximal middle cerebral artery (MCA) as a preprocedural evaluation to predict hidden running course distal to the thrombus. METHODS: This study retrospectively analyzed 191 consecutive patients (mean age, 67.5 ± 15.5 years; 100 women) who underwent time-of-flight-magnetic resonance angiography in our institution. Four landmarks of the MCA were assessed: division pattern, early branching pattern, length, and course pattern. Each geometric property was compared between cerebral hemispheres. Frequencies of symmetry and symmetry breaking were assessed. RESULTS: In 91% (bifurcation type, 87%; trifurcation type, 4%), branching patterns of the left and right M1 were symmetrical. Early frontal and/or temporal branches were observed in 31%, and the presence/absence of early branches was symmetrical in 70% cases. In 19%, M1 was classified as short M1, and classifications were identical between hemispheres in 74%. Running course of the M1 was symmetrical in 63%. Two or more parameters were symmetrical in 181 cases (95%). CONCLUSIONS: The symmetry of bilateral M1-2 structures was demonstrated in most cases from the perspectives of 4 parameters. The MCA symmetry can predict the running course of the MCA before crossing the occlusion site and shows potential benefits for neurointerventionalists.

Intentional Staged Clipping Following Previous Coil Embolization of Ruptured Aneurysm with a Branch Arising from the Neck: Technical Note.

AIM: To present a substitute strategy for clipping: coil embolization of the ruptured aneurysm followed by intentional, staged clipping. CASE DESCRIPTION: We treated five cases of ruptured intracranial aneurysms with branches arising from the neck. The mean aneurysm diameter was 4.4 mm. In the acute rupture phase, coiling was performed without adjunctive endovascular techniques with intentional preservation of the neck in all cases. To treat recurrence during follow-up, the previously coiled aneurysm was clipped, which did not occasion any complications. Postoperative imaging showed completely obliterated aneurysms and preserved branches. No rebleeding occurred during the interval between coiling and clipping, and no rebleeding or recurrence occurred after clipping. No treatment-related complications occurred after coiling and clipping. CONCLUSION: This two-stage strategy may be effective for hemostasis and branch preservation for small- and medium-sized ruptured aneurysms with a branch arising from the neck. This intentional two-stage strategy can be a substitute strategy for clipping in the acute rupture phase with an acceptable outcome if the patient cannot undergo clipping as the first-line treatment.

Acute Thrombectomy for Contralateral Internal Carotid Artery Occlusion after Revascularization Surgery for Quasi-moyamoya Disease: A Case Report.

Ischemic complications can occur after revascularization surgery for moyamoya disease, but acute contralateral internal carotid artery (ICA) occlusion is an extremely rare complication. The patient was a 51-year-old woman with no medical history. Left frontal lobe infarction and bilateral ICA terminal stenosis were identified by repeated transient right paresis and aphasia. We diagnosed her with quasi-moyamoya disease associated with hyperthyroidism and performed revascularization surgery for the symptomatic left side. Although neurological symptoms did not worsen immediately after the surgery, disturbance of consciousness, right conjugate deviation, and left paresis appeared 4 hr after the surgery. New infarction appeared in the right frontal lobe, and the blood signal beyond the right middle cerebral artery (MCA) disappeared on MRI and MRA. Mechanical thrombectomy (MT) using a suction catheter improved antegrade blood flow in the MCA. The left paresis remained at discharge (modified Rankin Scale score = 4), but she was able to walk independently 3 months after the operation and was independent at home. Acute contralateral ICA occlusion after revascularization for moyamoya disease is an extremely rare complication, but the symptoms can be severe and treatment should be considered. To the best of our knowledge, there have been no reports of MT for postoperative acute contralateral ICA occlusion. Since the results of endovascular treatment such as percutaneous transluminal angioplasty and stent placement for patients with moyamoya disease are poor, MT using an aspiration catheter could be a good treatment option.

Trans-cell Approach through Closed-cell Stent for Middle Meningeal Artery Embolization in Recurrent Chronic Subdural Hematoma.

We report a case of recurrent chronic subdural hematoma (CSDH) treated using the trans-cell approach through a closed-cell stent for middle meningeal artery embolization (MMAE). A 77-year-old man with acute ischemic stroke due to anterior circulation tandem occlusion was treated with intracranial thrombectomy and carotid artery stenting using a closed-cell stent 5 years ago. He experienced head trauma after a fall, which then developed into a CSDH. Burr hole surgery was performed twice, followed by MMAE considering the high possibility of recurrence due to antiplatelet therapy and brain atrophy after ischemic stroke. A distal access catheter was inserted into the external carotid artery through the closed-cell stent, and a microcatheter was navigated in the middle meningeal artery. The anterior and posterior convexity branches were embolized with 16.7% N-butyl cyanoacrylate. The postoperative course was favorable, and CT at 3-month follow-up showed a decrease in the hematoma. Even after the placement of the closed-cell stent, endovascular treatment of the external carotid artery is possible and can be a therapeutic option using the trans-cell approach.

Initial Report of the Perioperative Platelet Aggregation Test Using Hematracer ZEN in Neuroendovascular Therapy.

Objective: We report the characteristics of the platelet aggregation test using Hematracer ZEN (HTZ; DS medical, Tokyo, Japan) during the perioperative period. Methods: Among patients undergoing neuroendovascular treatment (EVT) at our hospital between June 2019 and June 2020, 42 consecutive patients with preoperative dual antiplatelet therapy (DAPT) were included. Oral administration of aspirin (ASA) at 81 mg and clopidogrel (CLP) at 75 mg was started 7 days before treatment (Flow Diverter [FD]: 14 days before). We evaluated platelet aggregation activity the day before treatment (FD: 2 days before) using HTZ. We adjusted the CLP dose according to the platelet aggregation test in each patient. We evaluated the platelet aggregating activity after EVT in patients requiring an intracranial stent or in which CLP was adjusted before EVT. Results: Platelet aggregating activity was able to be evaluated in all patients. In the preoperative examination, the efficacy of CLP was insufficient in one patient (2.4%), optimal medical effects were confirmed in 16 (38.1%), mildly excessive effects were noted in 10 (23.8%), and highly excessive effects were noted in 15 (35.7%). Reassessment was performed postoperatively in 20 patients. We switched CLP to prasugrel in one patient in which the CLP efficacy was considered insufficient in the preoperative evaluation. We reduced the CLP dose in seven patients with marked overdose, and the optimum range was reached in all. We did not adjust the CLP dose in 12 patients judged to have optimal or mildly excessive effects preoperatively, but 4 exhibited highly excessive drug efficacy and required CLP reduction. No postoperative symptomatic cerebral infarction or intracranial hemorrhage was observed (mean observation period: 11 months, range: 4-16 months). Conclusion: The platelet aggregation test using HTZ was simple and inexpensive, and was useful for adjusting the dose of antiplatelet drugs, but its utility should be evaluated in more patients.

De Novo Development of Moyamoya Disease after Stereotactic Radiosurgery for Brain Arteriovenous Malformation in a Patient With RNF213 p.Arg4810Lys (rs112735431).

BACKGROUND: Reports of cases diagnosed as Moyamoya disease (MMD) after stereotactic radiosurgery (SRS) for arteriovenous malformation (AVM) are extremely rare. In recent years, ring finger protein 213 (RNF213) has been identified as a susceptibility gene of MMD, but the mechanism by which MMD develops remains unclear. Those cases of de novo development of MMD may provide some clues to clarify the mechanism of progression of MMD. CASE DESCRIPTION: We report the case of de novo MMD that developed after SRS for AVM. This patient presented with a variant of the RNF213 gene. The intracranial internal carotid artery was not within the irradiation field; therefore it was obvious that the development of MMD was not caused by the direct effect of radiation in the current case study. Moreover, we demonstrated the decrease in velocity in the internal carotid artery prior to the development of MMD using phase-contrast magnetic resonance angiography. Previous studies demonstrated that progression of the pathological condition in the cerebral arteries in response to hemodynamic changes is enhanced in patients with RNF213 variants. CONCLUSIONS: Our findings indicate that the changes in the intracranial hemodynamics after SRS for AVM could trigger the de novo onset of MMD in patients with a genetic predisposition for the RNF213 variant.

Trapping, dome puncture, and direct suction decompression in conjunction with assistant superficial temporal artery- middle cerebral artery bypass to clip giant internal carotid artery bifurcation aneurysm.

BACKGROUND: Very large and giant aneurysms (≥20 mm) of the internal carotid artery (ICA) bifurcation (ICAbif) are definitely rare, and optimal treatment is not established. Endovascular treatments are reported as suboptimal due to difficulties of complete occlusion and tendencies to recanalization. Therefore, direct surgery remains an effective strategy if the clipping can be performed safely and reliably, although very difficult. CASE DESCRIPTION: Two cases of ICAbif aneurysms (>20 mm) were treated. Prior assistant superficial temporal artery (STA)-middle cerebral artery (MCA) bypass was performed to avoid ischemic complications during prolonged temporary occlusion of the arteries in both cases. In Case 1 (22-mm aneurysm), the dome was inadvertently torn in applying the clip because trapping had resulted in insufficient decompression. Therefore, in Case 2 (28-mm aneurysm), almost complete trapping of the aneurysm and subsequent dome puncture was performed, and the aneurysm was totally deflated by suction from the incision. This complete aneurysm decompression allowed safe dissection and successful clipping. CONCLUSION: Trapping, deliberate aneurysm dome puncture, and suction decompression from the incision in conjunction with assistant STA-MCA bypass can achieve complete aneurysm deflation, and these techniques enable safe dissection of the aneurysm and direct clipping of the aneurysm neck. Direct clipping with this technique for very large and giant ICAbif aneurysms may be the optimal treatment choice with the acceptable outcome if endovascular treatment remains suboptimal.

Endoscopic Transnasal Resection of Solitary Fibrous Tumor in the Optic Canal.

BACKGROUND: Tumors extending into the optic canal can cause progressive visual impairment because of optic nerve compression. Prompt surgical resection is often necessary. When the tumor is located medially in the optic canal, endoscopic transnasal surgery provides a safer, less invasive alternative to a transcranial approach. CASE DESCRIPTION: We recently encountered a case of small solitary fibrous tumor in the optic canal causing rapid visual deterioration. The radiographic findings of preoperative imaging studies were compatible with those of meningioma; however, unlike meningioma, bleeding from the tumor was profuse during the operation. The endoscopic transnasal approach was effective for handling the highly vascularized tumor in this delicate region, and gross total removal was achieved with postoperative gradual improvement in his visual function. Nevertheless, the tumor recurred after 6 months, and re-resection was performed using the same surgical corridor, followed by adjuvant radiotherapy. CONCLUSIONS: Endoscopic transnasal surgery is a valuable option for aggressive lesions in the optic canal. Although the efficacy of radiotherapy for solitary fibrous tumor remains controversial, it should be considered when the tumor shows progressive features.

Long-Term Patency of Posterior Auricular Artery-Middle Cerebral Artery Bypass for Adult-Onset Moyamoya Disease: Case Report and Review of Literature.

BACKGROUND: Direct extracranial-intracranial (EC-IC) bypass is one of the fundamental techniques to prevent recurrent stroke in patients with adult-onset ischemic moyamoya disease. When the standard superficial temporal artery (STA) cannot be used for a graft, the posterior auricular artery (PAA) can be a potential surrogate graft. CASE DESCRIPTION: In this article, the authors reported a 34-year-old female patient suffering from ischemic moyamoya disease. To widely revascularize the anterior half of the hemisphere, direct double EC-IC bypass was considered beneficial; however, she had only a single-branched STA but had a prominent branch of the PAA. After discussion, a direct double surgical revascularization was successfully performed using a combination of the STA-middle cerebral artery (MCA) and the PAA-MCA bypass. The authors herein reported the detailed surgical technique of the PAA-MCA bypass with an informative video of the actual procedure. To clearly define the feasibility of PAA-MCA bypass, the authors also conducted a literature review, yielding 3 previous articles describing the bypass. CONCLUSION: In conclusion, the PAA becomes a potential donor for EC-IC bypass as long as its diameter is approximately 1.0 mm. Even though the PAA-MCA bypass is not primarily considered in the initial revascularization, it can be useful as a combination bypass with other grafts or as a rescue for recurrent ischemia.