Sympathetic Nervous Hyperactivity Impairs Microcirculation Leading to Early Brain Injury After Subarachnoid Hemorrhage.

BACKGROUND: Although early brain injury (EBI) is recognized as a critical step following subarachnoid hemorrhage (SAH), its pathophysiology and underlying mechanisms remain poorly understood. Herein, we investigated the role of cerebral circulation in the acute phase using patient data and a mouse SAH model and evaluated its regulation via the sympathetic nervous system. METHODS: The cerebral circulation time and neurological outcomes in the human body were retrospectively examined in 34 SAH cases with ruptured anterior circulation aneurysms and 85 cases with unruptured anterior circulation cerebral aneurysms at Kanazawa University Hospital from January 2016 to December 2021. In a mouse study, a SAH model was created via endovascular perforation, and India-ink angiography was performed over time. Additionally, bilateral superior cervical ganglionectomy was performed immediately before surgery, and neurological scores and brain water content were evaluated after SAH. RESULTS: Cerebral circulation time was prolonged in the acute phase of SAH compared with that in the unruptured cerebral aneurysm group, especially in those with electrocardiographic changes. Furthermore, it was more prolonged in the poor prognosis group (modified Rankin Scale scores 3-6) than in the good prognosis group (modified Rankin Scale scores 0-2) at discharge. In mice, cerebral perfusion was significantly reduced at 1 and 3 hours after SAH and recovered at 6 hours. superior cervical ganglionectomy improved cerebral perfusion without altering the diameter of the middle cerebral artery at 1 hour and improved neurological outcomes at 48 hours after SAH. Consistently, brain edema, quantified by brain water content, was improved by superior cervical ganglionectomy 24 hours after SAH. CONCLUSIONS: Sympathetic hyperactivity may play a critical role in the development of EBI by impairing cerebral microcirculation and edema in the acute phase following SAH.

Factors related to high bifurcation level of common femoral artery.

BACKGROUND: Common femoral artery (CFA) puncture is performed for endovascular treatment. However, we sometimes experience branch punctures when the CFA bifurcation level is high. In this study, we examined the frequency of high CFA bifurcation level and related factors. METHODS: The CFA bifurcation level was identified in 100 patients, who underwent cerebral angiography or endovascular treatment by femoral artery (FA) puncture, on 191 sides. The height of the CFA bifurcation level was classified into three groups: normal, high, and very high. Age, gender, left-right difference, height, weight, body mass index, and comorbidities, including hypertension, dyslipidemia, and diabetes, were examined to determine the factors associated with high CFA bifurcation level. RESULTS: The normal, high, and very high groups were on 142, 35, and 14 sides, respectively. The high and very high groups, which were defined as high CFA bifurcation levels, accounted for 25% of all patients. Multivariate analysis revealed that the proportion of patients with high CFA bifurcation levels was higher in the elderly (p = 0.009) and those with a history of diabetes (p = 0.042). CONCLUSIONS: Approximately one-fourth of all patients undergoing cerebral angiography or endovascular treatment by FA puncture had high CFA bifurcation levels, which had a significant association with old age and history of diabetes. For urgent treatment, FA puncture might be performed at a higher level below the inguinal ligament if patients are elderly of those with a history of diabetes.

Intraoperative rupture of intracerebral aneurysm immediately after meningioma resection: a case report.

BACKGROUND: Meningiomas and unruptured cerebral aneurysms (UCAs) rarely coexist. However, the treatment strategy remains to be fully elucidated. This report is a first report that UCA related to the tumor feeder intraoperatively ruptured when the meningioma was resected. CASE PRESENTATION: Herein, we present a case of meningioma coexisting with contralateral UCA related to a tumor feeder. Immediately after the meningioma was resected, intraoperative acute brain swelling due to rupture of the contralateral aneurysm appeared. The swollen brain protruding into the epidural space was resected, following contralateral ruptured aneurysm was performed by endovascular surgery. Intensive neurological treatment was administered and the patient gradually recovered. CONCLUSION: This report highlights the possibility of intraoperative UCA rupture related to the tumor feeder when the meningioma is resected.

Hemodynamic factor evaluation using computational fluid dynamics analysis for de novo bleb formation in unruptured intracranial aneurysms.

BACKGROUND: Although bleb formation increases the risk of rupture of intracranial aneurysms, previous computational fluid dynamic (CFD) studies have been unable to identify robust causative hemodynamic factors, due to the morphological differences of prebleb aneurysm models and a small number of aneurysms with de novo bleb formation. This study investigated the influences of differences in the aneurysm-models and identify causative hemodynamic factors for de novo bleb formation. MATERIALS AND METHODS: CFD analysis was conducted on three aneurysm models, actual prebleb, postbleb, and virtual prebleb models of two unruptured aneurysms with de novo bleb formation. A new multipoint method was introduced in this study. We evenly distributed points with a 0.5-mm distance on the aneurysm surface of the actual prebleb models (146 and 152 points in the individual aneurysm, respectively), and we statistically compared hemodynamics at the points in the areas with and without bleb formation (19 and 279 points, respectively). RESULTS: Visually, blebs formed on an aneurysm surface area with similar hemodynamic characteristics in the actual and virtual prebleb models. Statistical analysis using the multipoint method revealed that the de novo bleb formation area was significantly correlated with high pressure (p < 0.001), low wall shear stress (WSS) (p < 0.001), and the center of divergent WSS vectors (p = 0.025). CONCLUSIONS: De novo bleb formation in intracranial aneurysms may occur in areas associated with the combination of high pressure, low WSS, and the center of divergent WSS vectors. The multipoint method is useful for statistical analysis of hemodynamics in a limited number of aneurysms.

Late complications of visual impairment and hydrocephalus after flow diverter-assisted coil embolisation for intracranial large aneurysm: a case report and literature review.

Large or giant paraclinoid aneurysms typically have good indication for flow diverter (FD) treatment. Here, we report a very rare case of a patient with an unruptured supraclinoid large aneurysm who underwent FD deployment with coil embolisation that resulted in delayed visual field defect (VFD) and hydrocephalus. A 75-year-old woman with a large right supraclinoid aneurysm presented with severe hemianopia in the right eye. She underwent FD deployment with coil embolisation of the aneurysm. However, permanent left visual field loss occurred four months after surgery. Magnetic resonance imaging (MRI) showed severe oedema surrounding the aneurysm along the optic tract. Inflammation led to postoperative hydrocephalus, requiring ventriculoperitoneal shunt placement. To the best of our knowledge, this is the first report of both a delayed VFD and hydrocephalus following FD treatment. In cases of FD treatment with coil embolisation for large paraclinoid aneurysms, clinicians should keep in mind that postoperative visual impairment or/and hydrocephalus may occur.

Prediction of internal carotid artery aneurysm recurrence by pressure difference at the coil mass surface.

PURPOSE: A previous study on computational fluid dynamics reported that a high pressure difference (PD) at the surface of a coil mass is a strong predictor of aneurysm recurrence after coil embolization. PD was calculated using a virtual post-coiling model (VM), created by manually cutting the aneurysm by the flat plane from an anatomic model created with pre-coil embolization data; however, its credibility has not been fully evaluated. This study aims to clarify whether PD values calculated using the post-coiling model, which reflects the actual coil plane, are a strong predictor of aneurysm recurrence. METHODS: Fifty internal carotid artery aneurysms treated with endovascular coil embolization were analyzed (7 recanalized, 43 stable). We created and subjected two post-coiling models, namely, VM and the real post-coiling model (RM), constructed from the post-coil embolization data. The relationship between PD and aneurysm recurrence was examined using these models. PD and its constituent three parameters were compared between VM and RM. RESULTS: PD values calculated using RM showed significantly higher aneurysm recurrence in recurrence group than stable group (p < 0.001), and multivariate analysis showed that PD in RM (p = 0.02; odds ratio, 36.24) was significantly associated with aneurysm recurrence. The receiver operating characteristic analysis revealed that PD values accurately predicted aneurysm recurrence (area under the curve, 0.977; cutoff value, 3.08; sensitivity, 100%; specificity, 97.7%). All four parameters showed a significant correlation with VM and RM (p < 0.001). CONCLUSION: Use of PD to predict recurrence after coil embolization can be clinically relevant.

Inflow Hemodynamics of Intracranial Aneurysms: A Comparison of Computational Fluid Dynamics and 4D Flow Magnetic Resonance Imaging.

PURPOSE: Although the inflow hemodynamics of cerebral aneurysms are key factors in their rupture and recurrence after endovascular treatments, the most available method for inflow hemodynamics evaluation remains unestablished. We compared the efficacy of inflow hemodynamics evaluation using computational fluid dynamics (CFD) analysis and that using four-dimensional (4D) flow magnetic resonance imaging (MRI). METHODS: In 23 unruptured cerebral aneurysms, the inflow hemodynamics was evaluated using both CFD and 4D flow MRI. The evaluated parameters included visually classified inflow jet patterns, the inflow rate ratio (the ratio of the inflow rate at the aneurysmal orifice to the flow rate in the proximal parent artery), and the velocity ratio (the ratio of the inflow velocity to the velocity in the proximal parent artery). The Shapiro-Wilk test was used to assess the normality of variable data, and logarithmic transformation was performed for variables with non-normal distributions. Data analysis was performed using Pearson correlation analyses and the chi-square test. RESULTS: There was a significant correlation between inflow jet patterns evaluated by CFD and 4D flow MRI (p = 0.008). Moreover, there was a strong correlation between the inflow rate ratios evaluated by CFD and 4D flow MRI (r = 0.801; p <0.001). Furthermore, there was a moderate correlation between the velocity ratios measured by CFD and 4D flow MRI (r = 0.559; p = 0.008). CONCLUSION: Inflow hemodynamics evaluated by CFD analysis and 4D flow MRI showed good correlations in inflow jet pattern, inflow rate ratio, and velocity ratio.

N-myc downstream-regulated gene 2 protects blood-brain barrier integrity following cerebral ischemia.

Disruption of the blood-brain barrier (BBB) following cerebral ischemia is closely related to the infiltration of peripheral cells into the brain, progression of lesion formation, and clinical exacerbation. However, the mechanism that regulates BBB integrity, especially after permanent ischemia, remains unclear. Here, we present evidence that astrocytic N-myc downstream-regulated gene 2 (NDRG2), a differentiation- and stress-associated molecule, may function as a modulator of BBB permeability following ischemic stroke, using a mouse model of permanent cerebral ischemia. Immunohistological analysis showed that the expression of NDRG2 increases dominantly in astrocytes following permanent middle cerebral artery occlusion (MCAO). Genetic deletion of Ndrg2 exhibited enhanced levels of infarct volume and accumulation of immune cells into the ipsilateral brain hemisphere following ischemia. Extravasation of serum proteins including fibrinogen and immunoglobulin, after MCAO, was enhanced at the ischemic core and perivascular region of the peri-infarct area in the ipsilateral cortex of Ndrg2-deficient mice. Furthermore, the expression of matrix metalloproteinases (MMPs) after MCAO markedly increased in Ndrg2-/- mice. In culture, expression and secretion of MMP-3 was increased in Ndrg2-/- astrocytes, and this increase was reversed by adenovirus-mediated re-expression of NDRG2. These findings suggest that NDRG2, expressed in astrocytes, may play a critical role in the regulation of BBB permeability and immune cell infiltration through the modulation of MMP expression following cerebral ischemia.

Deletion of Atf6α impairs astroglial activation and enhances neuronal death following brain ischemia in mice.

To dissect the role of endoplasmic reticulum (ER) stress and unfolded protein response in brain ischemia, we investigated the relevance of activating transcription factor 6α (ATF6α), a master transcriptional factor in the unfolded protein response, after permanent middle cerebral artery occlusion (MCAO) in mice. Enhanced expression of glucose-regulated protein78, a downstream molecular chaperone of ATF6α, was observed in both neurons and glia in the peri-infarct region of wild-type mice after MCAO. Analysis using wild-type and Atf6α(-/-) mice revealed a larger infarct volume and increased cell death in the peri-ischemic region of Atf6α(-/-) mice 5 days after MCAO. These phenotypes in Atf6α(-/-) mice were associated with reduced levels of astroglial activation/glial scar formation, and a spread of tissue damage into the non-infarct area. Further analysis in mice and cultured astrocytes revealed that signal transducer and activator of transcription 3 (STAT3)-glial fibrillary acidic protein signaling were diminished in Atf6α(-/-) astrocytes. A chemical chaperone, 4-phenylbutyrate, restored STAT3-glial fibrillary acidic protein signaling, while ER stressors, such as tunicamycin and thapsigargin, almost completely abolished signaling in cultured astrocytes. Furthermore, ER stress-induced deactivation of STAT3 was mediated, at least in part, by the ER stress-responsive tyrosine phosphatase, TC-PTP/PTPN2. These results suggest that ER stress plays critical roles in determining the level of astroglial activation and neuronal survival after brain ischemia.

Correction: Recurrence pattern predicts aneurysm rupture after coil embolization.

[This corrects the article DOI: 10.1371/journal.pone.0261996.].

Recurrence of an extracranial internal carotid artery aneurysm treated with STA-MCA bypass and trapping due to neovascularization from an ascending pharyngeal artery: illustrative case.

BACKGROUND: Extracranial internal carotid artery aneurysms (EICAs) are rare. Although a high mortality risk has been reported in nonoperated cases, the optimal treatment for EICAs remains unknown. OBSERVATIONS: A 79-year-old female presented with painless swelling in the right neck. Imaging revealed a giant EICA with a maximum diameter of 3.2 cm. Superficial temporal artery-middle cerebral artery bypass and internal carotid artery (ICA) trapping were performed. Because the distal aneurysm edge was at the C1 level, the distal portion of the aneurysm was occluded by endovascular coiling, and the proximal portion was surgically ligated. Blood flow into the aneurysm disappeared after the operation. Three years postsurgery, enlargement of the aneurysm with blood flow from the ascending pharyngeal artery (APA) was detected. The EICA was resected after coiling the APA and ligating both ends of the aneurysm. Pathologically, neovascularization within the aneurysm wall was observed. LESSONS: Even if blood flow into an EICA disappears after ICA trapping, the EICAs can enlarge due to neovascularization from the neighboring artery. From the outset, removal of the aneurysm should be considered as a radical treatment strategy for giant EICAs.

Partially thrombosed distal posterior cerebral artery aneurysm treated with surgical trapping through occipital transtentorial approach assisted by endovascular coil embolization.

Background: Posterior cerebral artery (PCA) aneurysms are relatively rare. PCA aneurysms tend to be large, giant, fusiform, and partially thrombosed. Surgical treatments, such as neck clipping and trapping with or without bypass surgery, are curative treatments for thrombosed intracranial aneurysms. Few cases of surgical treatment of distal PCA aneurysms have been reported. We treated a partially thrombosed distal PCA aneurysm by trapping through the occipital transtentorial approach (OTA) assisted by endovascular coil embolization. Case Description: A 21-year-old woman presented with a sudden headache. Brain computed tomography, magnetic resonance imaging, and a cerebral angiogram revealed a partially thrombosed aneurysm in the left PCA P3 segment. Her headaches had improved once within several days, but reoccurred due to an enlarged thrombosed aneurysm. Endovascular coil embolization was performed to assist the surgery. The aneurysm and the distal artery of the aneurysm were embolized to interrupt the blood flow into the aneurysm. The following day, trapping of the aneurysm was performed through the OTA. Eventually, we performed aneurysm excision because trapping alone was considered to have the potential for regrowth of the aneurysm. The patient's postoperative course was uneventful. No recurrence of the aneurysm was observed at the 2-year follow-up. Conclusion: OTA could be useful for the treatment of distal PCA aneurysms, whereas coil embolization may support the surgical treatment of partially thrombosed intracranial aneurysms.

Targeted transvenous embolization of a dural arteriovenous fistula at the jugular tubercle venous complex.

Background: Dural arteriovenous fistulas (dAVFs) occurring near the hypoglossal canal are rare. Detailed evaluation of vascular structures can identify shunt pouches at the jugular tubercle venous complex (JTVC) in the bone near the hypoglossal canal. Although the JTVC has several venous connections, including the hypoglossal canal, there have been no reports of transvenous embolization (TVE) of a dAVF at the JTVC using an approach route other than the hypoglossal canal. This report describes the first case of complete occlusion with targeted TVE using an alternative approach route in a 70-year-old woman presenting with tinnitus diagnosed with dAVF at the JTVC. Case Description: The patient had no history of head trauma or other preexisting conditions. Magnetic resonance imaging (MRI) showed no abnormal findings in the brain parenchyma. Magnetic resonance angiography (MRA) revealed a dAVF near the ACC. The shunt pouch was located in the JTVC, near the left hypoglossal canal, with feeders from the bilateral ascending pharyngeal arteries and occipital arteries, left meningohypophyseal trunk, and odontoid arch of the left vertebral artery. TVE was performed near the shunt pouch. Localized packing of the shunt point was achieved. The patient's tinnitus improved. Postoperative MRI showed disappearance of the shunt without any complications. No recurrence was observed on MRA 6 months after treatment. Conclusion: Our results suggest targeted TVE is an effective treatment for dAVFs at the JTVC.

Comparison of Endovascular Therapy for Ruptured Cerebral Aneurysm during Spasm and Nonspasm Period.

Objective Cerebral vasospasm complicates the treatment of aneurysmal subarachnoid hemorrhage, and the optimal timing of surgery for ruptured intracranial aneurysm diagnosed during the cerebral vasospasm period has been a matter of debate. This study aimed to clarify the differences in endovascular treatment outcomes between the timing of intervention during spasm and nonspasm. Methods and Materials We retrospectively reviewed 68 consecutive patients with ruptured cerebral aneurysms who underwent coil embolization between January 2016 and March 2021. Clinical presentations, radiographic findings, and outcomes were retrospectively reviewed and compared between patients who were treated at the time of spasm and nonspasm. Information regarding the following clinical characteristics was collected: age, sex, World Federation of Neurosurgical Societies (WFNS) grade on admission, aneurysm morphology, treatment result, and outcome. We defined from day 4 to day 14 as the timing of spasm, and vasospasm as more than 30% narrowing of the proximal anterior cerebral artery, middle cerebral artery, and internal carotid artery segment during the second examination compared with the first. The chi-squared test or Fisher's exact test were performed to evaluate the covariates for binary categorical dependent variables as appropriate, and nonnormal variables were compared using the Mann-Whitney U test. Results Ten patients (14.7%) underwent coil embolization at the time of vasospasm. Age, sex, WFNS grade, and aneurysm morphology were not different between the spasm and nonspasm groups. Additionally, there were no significant between-group differences in volume embolization ratio, procedure-related complications, occurrence of delayed cerebral ischemia, and outcome at discharge. Conclusion There were no significant between-group differences in treatment results and outcomes between the spasm and nonspasm groups. Endovascular treatment at the time of vasospasm could be the optimal treatment method for ruptured cerebral aneurysms.

Recurrence pattern predicts aneurysm rupture after coil embolization.

INTRODUCTION: Hemorrhage from a recurrent aneurysm is a major concern after coiling for intracranial aneurysms. We aimed to identify aneurysm recurrence patterns associated with hemorrhage. MATERIAL AND METHODS: We investigated radiological data of patients who underwent coiling for intracranial aneurysms in 2008-2016 and were followed-up for at least 6 months. Aneurysm recurrence patterns were classified as: type Ⅰ, enlargement of aneurysm neck; type Ⅱ, recurrent cavity within the coil mass; type Ⅲ, recurrent cavity along the aneurysm wall; and type Ⅳ, formation of a daughter sac. We evaluated the incidence of various recurrence patterns with or without hemorrhage. RESULTS: Of the 173 aneurysms included in the study (mean follow-up period, 32 months; range, 6-99 months), 22 (13%) recurred and required re-treatment. The recurrence patterns included type Ⅰ, Ⅱ, Ⅲ, and Ⅳ in 7 (4%), 4 (2%), 9 (5%), and 2 (1%) cases, respectively. Most of the type Ⅰ, Ⅱ, and Ⅲ recurrences occurred within 1 year, and type Ⅳ occurred at 7 years after coiling. Three aneurysms exhibited hemorrhage, one with type Ⅲ and two with type Ⅳ pattern. The two aneurysms with type Ⅳ recurrence initially occurred as type Ⅰ; however, the recurrent neck enlarged gradually, resulting in new sac formation. CONCLUSIONS: We recommend prompt re-treatment for aneurysms recurring with type Ⅲ or Ⅳ patterns, as such patterns were associated with hemorrhage. Furthermore, we need a special care to type Ⅰ recurrence with enlargement of recurrent neck because this specific pattern may develop to type Ⅳ.

Ocular ischemic syndrome due to severe internal carotid artery stenosis improved by intracranial stent placement: A case report.

BACKGROUND: Treatment of cervical internal carotid artery (ICA) stenosis has contributed to the improvement of ocular ischemic syndrome. However, there have been few cases of visual impairment caused by ocular ischemic syndrome due to intracranial ICA stenosis, which improved through intracranial stent placement. CASE DESCRIPTION: A 76-year-old man presented with right-sided paralysis. Radiographic examination revealed severe stenosis of the left intracranial ICA (distal cavernous-infraclinoid portion) and a watershed infarction of the left cerebral hemisphere. Conservative therapy including antiplatelet drugs was initiated, but severe visual acuity disturbance in his left eye occurred 1 month after onset. The antegrade ocular artery flow recovered after urgent intracranial stent placement, and his vision improved immediately after the procedure. CONCLUSION: Visual impairment presenting as ocular ischemic syndrome can occur due to severe stenosis of the intracranial ICA, and treatment of these lesions could improve the symptoms.

Usefulness of 2D-Perfusion Analysis for the Assessment of Unilateral Cervical Internal Carotid Artery Stenosis.

Objective: We investigated the usefulness of 2D-perfusion analysis for the evaluation of cerebral blood flow in unilateral cervical internal carotid artery stenosis. Methods: We conducted a 2D-perfusion analysis during cerebral angiography and 123I-iodoamphetamine (IMP) single photon emission computed tomography (SPECT) for unilateral cervical internal carotid artery stenosis without contralateral stenosis. The relationship between the ratio of the lesion side to the normal side in the parameters obtained by 2D-perfusion and the value calculated by stereotactic extraction estimation (SEE) analysis of SPECT was statistically examined. Results: The ratios of the lesion side to the normal side regarding the peak arrival time (AT; time to peak [TTP]) of the contrast agent and the mean filling time (mean transit time [MTT]) of the contrast agent in 2D-perfusion significantly correlated with the area of Stage II and increase ratio (I.R) ≤30% in the SEE analysis (p = 0.002, 0.003). Conclusion: 2D-perfusion analysis can be used to estimate the extent of impaired cerebrovascular reserve (CVR) area in unilateral internal carotid artery stenosis.

Prediction of Post-Embolization Recurrence of Anterior Communicating Aneurysms with A1 Segment Asymmetry by Fluid Dynamic Analysis.

Objective: The increased surface pressure of the coil mass calculated by computational fluid dynamics (CFD) analysis has been reported to be associated with the recurrence of internal carotid aneurysms after coil embolization. In this study, we investigated the relationship between the pressure on the coil surface and the recurrence of anterior communicating aneurysms. Methods: Among patients with anterior communicating aneurysms who underwent coil embolization at a volume embolization rate of 20% or more without using a stent, only one proximal anterior communicating artery (A1) was visualized by magnetic resonance angiography (MRA). A virtual post-coiling model was created by eliminating the aneurysm at the neck position from the blood vessel model based on three-dimensional rotational angiography (3D-RA) data before treatment, and the neck plane was defined as the virtual coil plane. Using CFD analysis, the pressure difference (PD) was calculated by subtracting the average pressure of A1 from the maximum pressure on the virtual coil surface and dividing by the dynamic pressure of A1 for normalization. PD was statistically compared between the recurrent group and the non-recurrent group. Results: Four of 10 patients with anterior communicating aneurysms exhibited recurrence. The PD was 2.54 ± 0.24 and 2.12 ± 0.26 in the recurrent and non-recurrent groups, respectively, and was significantly higher in the recurrent group (p=0.038). In the receiver operating characteristics (ROC) analysis, the area under the curve (AUC) was 0.917, and with a cutoff value of 2.31, the sensitivity was 1.000 and the specificity was 0.833. Conclusion: PD was considered a predictor of recurrence after coil embolization in anterior communicating aneurysms with asymmetrical A1. Preoperative prediction of recurrence after cerebral aneurysm embolization may be possible using CFD analysis.

Extracranial-intracranial high-flow bypass as a rescue therapy for incomplete cerebral aneurysm occlusion after flow diversion: A case report.

BACKGROUND: Excellent treatment outcomes using a pipeline embolization device (PED) have been reported. However, several limitations exist. For example, patients must receive antiplatelet therapy for at least several months, and few alternative treatments exist except for inserting additional flow diverter stents in cases where aneurysm obliteration is not obtained. CASE DESCRIPTION: A 67-year-old female suffered from an asymptomatic large aneurysm of the left paraclinoid internal carotid artery (ICA). She underwent endovascular coil embolization, but coil compaction was confirmed at 2-year follow-up. A PED was inserted as an additional treatment. Unfortunately, the patient was required to discontinue antiplatelet therapy to undergo orthopedic surgery for her severe osteoarthritis of the knee. However, surveillance imaging performed 2 years after insertion of the PED revealed persistent filling into the aneurysm, and we could not stop the antiplatelet therapy to proceed with orthopedic surgery. Therefore, we performed ICA trapping with extracranial-intracranial high-flow bypass to cease antiplatelet therapy promptly. Antiplatelet therapy was completed 3 months after the rescue surgery, and the patient underwent orthopedic surgery. CONCLUSION: The authors describe a case of failure of complete obliteration after treatment using a PED, which required cessation of antiplatelet therapy to receive orthopedic surgery. Although safety and efficacy of PED treatment have been reported, we must consider the possibility of other diseases requiring discontinuation of antiplatelet therapy after PED embolization.

Cavernous Sinus Dural Arteriovenous Fistula with an Enhanced Lesion in the Brainstem Mimicking a Malignant Tumor.

BACKGROUND: Cavernous sinus (CS) dural arteriovenous fistula (dAVF) with an enhanced lesion in the brainstem is rare, and an enhanced lesion in the brainstem might be indicative of irreversibility. CASE DESCRIPTION: A 77-year-old woman presented with double vision and ataxia. Magnetic resonance imaging showed a unilateral enhancement lesion in the pons, so a malignant brain tumor was suspected. A cerebral angiogram revealed CS-dAVF with retrograde leptomeningeal venous drainage (RLVD) to the brainstem. Transvenous embolization with selective coil embolization of RLVD was performed, and the symptoms and imaging improved dramatically. CONCLUSIONS: DAVFs with RLVD should be mentioned as a differential diagnosis of enhanced lesions in the brainstem. Transvenous embolization with selective coil embolization of RLVD was effective for the treatment of CS-dAVF, and a unilateral enhanced brainstem lesion may be reversible.