Impact of immediate general anesthesia in the emergency room on prevention of rebleeding after subarachnoid hemorrhage.

BACKGROUND: Aneurysm rebleeding is fatal in patients with aneurysmal subarachnoid hemorrhage (aSAH). We aimed to investigate whether immediate general anesthesia (iGA) management in the emergency room, upon arrival, prevents rebleeding after admission and reduces mortality following aSAH. METHODS: The clinical data of 3033 patients with World Federation of Neurosurgical Societies (WFNS) grade 1, 2, or 3 aSAH from the Nagasaki SAH Registry Study between 2001 and 2018 were retrospectively analyzed. iGA was defined as sedation and analgesia using intravenous anesthetics and opioids combined with intubation induction. We calculated crude and adjusted odds ratios to evaluate the associations between iGA and the risk of rebleeding/death using multivariable logistic regression models with fully conditional specification for multiple imputations. In the analysis of the relationship between iGA and death, we excluded patients with aSAH who died within 3 days after the onset of symptoms. RESULTS: Of the 3033 patients with aSAH who met the eligibility criteria, 175 patients (5.8%) received iGA (mean age, 62.4 years; 49 were male). Heart disease, WFNS grade, and lack of iGA were independently associated with rebleeding in the multivariable analysis with multiple imputations. Among the 3033 patients, 15 were excluded due to death within 3 days after the onset of symptoms. After excluding these cases, our analysis revealed that age, diabetes mellitus, history of cerebrovascular disease, WFNS grade, Fisher grade, lack of iGA, rebleeding, postoperative rebleeding, no shunt operation, and symptomatic spasm were independently associated with mortality. CONCLUSIONS: Management by iGA was associated with a 0.28-fold decrease in the risks of both rebleeding and mortality in patients with aSAH, even after adjusting for the patient's history of diseases, comorbidities, and aSAH status. Thus, iGA can be a treatment for the prevention of rebleeding before aneurysmal obliteration treatment.

Exploration of Pericyte-Derived Factors Implicated in Lung Cancer Brain Metastasis Protection: A Pilot Messenger RNA Sequencing Using the Blood-Brain Barrier In Vitro Model.

Metastatic brain tumors have poor prognoses and pose unmet clinical problems for the patients. The blood-brain barrier (BBB) implication is supposed to play a major role in brain metastasis. However, the role of pericytes remains to be elucidated in the brain metastasis. This pilot study described the expression profile of interactions between pericytes, endothelial cells, and cancer cells. We applied an in vitro BBB model with rat primary cultured BBB-related cells (endothelial cells and pericytes), and performed the gene expression analyses of pericytes under the lung cancer cells coculture conditions. Pericytes demonstrated inhibition of the cancer cell proliferation significantly (p < 0.05). RNA was extracted from the pericytes, complementary DNA library was prepared, and RNA-seq was performed. The sequence read data were analyzed on the Management and Analysis System for Enormous Reads and Tag Count Comparison-Graphical User Interface platforms. No statistically or biologically significant differentially expressed genes (DEGs) were detected in the explanatory analyses. Lot-specific DEG detection demonstrated significant decreases in the expression of two genes (Wwtr1 and Acin1), and enrichment analyses using Metascape software revealed the inhibition of apoptotic processes in fibroblasts. Our results suggest that the expression profiles of brain pericytes are partially implicated in the prevention of lung cancer metastasis to the brain. Pericytes exerted an anti-metastatic effect in the BBB model, and their neurohumoral factors remain to be elucidated.

A Spontaneous Extracranial Internal Carotid Artery Dissection with Autosomal Dominant Polycystic Kidney Disease: A Case Report and Literature Review.

Background and Objectives: Non-cystic manifestation of autosomal dominant polycystic kidney disease (ADPKD) is an important risk factor for cerebral aneurysms. In this report, we describe a rare spontaneous internal carotid artery (ICA) dissection in a patient with ADPKD. Observations: A 38-year-old woman with a history of ADPKD and acute myocardial infarction due to coronary artery dissection experienced severe spontaneous pain on the left side of her neck. Magnetic resonance imaging (MRI) revealed a severe left ICA stenosis localized at its origin. Carotid plaque MRI showed that the stenotic lesion was due to a subacute intramural hematoma. Close follow-up by an imaging study was performed under the diagnosis of spontaneous extracranial ICA dissection, and spontaneous regression of the intramural hematoma was observed uneventfully. Conclusions: When patients with a history of ADPKD present with severe neck pain, it is crucial to consider the possibility of a spontaneous ICA dissection. A carotid plaque MRI is beneficial in the differential diagnosis. Conservative management may benefit patients without ischemic symptoms.

Characteristics of aneurysmal subarachnoid hemorrhage associated with rheumatic disease.

Spontaneous subarachnoid hemorrhage (SAH) occurs due to intracranial aneurysm rupture in most cases. Rheumatic disease may cause vessel wall inflammation, which can increase the risk of rupture. However, the characteristics of SAH with rheumatic disease are unknown. This study aimed to evaluate SAH features in patients with rheumatic disease. We retrospectively analyzed clinical data of 5066 patients from the Nagasaki SAH Registry Study who had been diagnosed with aneurysmal SAH between 2001 and 2018. We evaluated the SAH characteristics in patients with rheumatic disease using multivariable logistic regression analysis. In total, 102 patients (2.0%, 11 men and 91 women, median age 69.0 [57.0-75.5]) had rheumatic disease. In these patients, univariate logistic regression analysis showed that sex, hypertension, family history of SAH, smoking history, World Federation of Neurosurgical Societies grade on admission, aneurysm size, multiple aneurysms, treatment, and symptomatic spasms were associated with SAH. Multivariable logistic regression analysis showed that characteristics independently associated with SAH in rheumatic disease were female sex (odds ratio [OR] 3.38; 95% confidence interval [CI] 1.81-6.93, P < 0.001), hypertension (OR 0.60; 95% CI 0.40-0.90, P = 0.012), family history of SAH (OR 0.18; 95% CI 0.01-0.80, P = 0.020), small ruptured aneurysms (OR 1.50; 95% CI 1.02-2.24, P = 0.048), and multiple aneurysms (OR 1.69; 95% CI 1.09-2.58, P = 0.021) in comparison with SAH without rheumatic disease. In conclusion, SAH in patients with rheumatic disease was characterized by small multiple aneurysms, regardless of the low incidence of hypertension and family history of SAH.

A1 Segment Unruptured Aneurysm of Persistent Primitive Olfactory Artery Coexisted with Accessory Middle Cerebral Artery.

A persistent primitive olfactory artery (PPOA) is a rare anomaly of anterior cerebral artery (ACA), which generally arises from the internal carotid artery (ICA), runs along the olfactory tract, and makes a hairpin bend to supply the territory of the distal ACA. PPOA is also associated with cerebral aneurysms. An accessory MCA is a variant of the middle cerebral artery (MCA) that arises from either the proximal or distal portion of the A1 segment of the ACA, which runs parallel to the course of the MCA and supplies some of the MCA territory. We experienced a rare case of coexistence of PPOA with an unruptured aneurysm and accessory MCA. Three-dimensional computed tomographic angiography (3D-CTA) has an excellent picture of the spatial relationship of the surrounding bony and vascular structure.

Carotid Endarterectomy Using Lone Star Retractor System.

Cervical carotid disease is typical atherosclerosis, which is responsible for ischemic stroke. The effectiveness of carotid endarterectomy (CEA) for advanced carotid stenosis has been established in many large studies, and CEA is the gold standard in surgical treatment. On the other hand, endovascular carotid artery stenting (CAS) has become increasingly popular recently. It is very important to avoid any complications to maintain the effectiveness of CEA. The retractor device is important for the exposure of carotid arteries and for the safe surgical manipulation. We have started to use lone star retractor system (LSRS) to deploy the surgical field. LSRS provides the usability to handle and a shallower surgical field without the disturbance of surgical manipulation. And it can facilitate exposure of the distal internal carotid artery because surgeon can retract freely in whole circumference by towing with moderate strength. LSRS may bring the smoother and easier surgical manipulations in CEA.

Pericytes Suppress Brain Metastasis from Lung Cancer In Vitro.

Metastasis of lung cancer to the brain is associated with poor outcomes and limited therapeutic options. The blood-brain barrier (BBB) plays a major role in brain metastasis. However, little is known about the role of pericytes in brain metastasis formation. This study aimed to reveal the interaction between pericytes and cancer cells. We established in vitro BBB models with rat primary cultured BBB-related cells (endothelial cells, astrocytes, and pericytes) and investigated the relationship between BBB-related cells and metastatic cancer cell lines. We observed a significant decrease in transendothelial electrical resistance with metastatic cancer cells in monolayer and coculture models with astrocytes. In contrast, the coculture model with pericytes showed inhibition of the decrease in transendothelial electrical resistance with metastatic cancer cells. In addition, the expression of tight junction protein was preserved only in the coculture model with pericytes. The conditioned medium of pericytes with metastatic cancer cells suppressed the proliferation of the cancer cells significantly. This study revealed that brain pericytes are the major regulators of the resistance of the BBB to lung cancer metastasis to the brain. Pericytes exert an anti-metastatic effect and thus have potential for the preventive treatment of brain metastasis.

Comparison of the rate of dedifferentiation with increasing passages among cell sources for an in vitro model of the blood-brain barrier.

Cell culture-based blood-brain barrier (BBB) models are useful experimental tools for developing central nervous system drugs. Several endothelial cell sources exist for BBB models, including primary cultured brain endothelial cells and immortalized cell lines. Among them, primary cell-based models are considered suitable for the functional analysis of the BBB; however, little is known about the utility of low-passage brain endothelial cells for this purpose. In this study, we investigated the effect of passage on brain endothelial cells from human, mouse and rat brain tissue as BBB models. We established in vitro BBB models using primary brain endothelial cells (Passage 1-Passage 4) from humans, mice, and rats. To analyze the effect of cell type on BBB function, we evaluated transendothelial electrical resistance (TEER) and performed immunofluorescence staining of tight junction proteins. Among the brain endothelial cell models, TEER was highest in the Passage 1 (P1) cell-based BBB model. There was no adequate increase in TEER in other low-passage cultures (P2-P4). A confluent, non-overlapping, uniform monolayer of cells in all P1 cell-based models was visible on immunostaining of tight junction proteins, whereas it was weak or undetectable in more passaged cultures. Increasing passages cultured of brain endothelial cells did not exhibit restrictive BBB function regardless of the cell source and despite culturing with pericytes and astrocytes. Among the tested culture models, only the lowest cultured cell-based models are suitable for functional analysis of the BBB.

First Bite Syndrome Following Carotid Endarterectomy.

A 67-year-old man with a high position carotid plaque presented with severe pain in ipsilateral parotid region several days after carotid endarterectomy (CEA). The pain occurred at the first bite of each meal and resolved as further bite. We diagnosed the pain as first bite syndrome (FBS). FBS is infrequent but known as a complication associated with parapharyngeal space surgery. The pain is characterized by sharp pain in the parotid region associated with mastication. The cause is unclear but thought to the result from sympathetic denervation of the parotid gland, followed by parasympathetic nerve hypersensitivity. Only five cases associated with carotid endarterectomy (CEA) have been reported. We should be in mind that CEA for high position plaque is one of the risk factors to cause FBS associated with CEA. Neurologists and vascular surgeons as well as otolaryngologists should all be informed FBS as one of the complications after carotid endarterectomy.

Hyperhomocysteinemia Causes Severe Intraoperative Thrombotic Tendency in Superficial Temporal Artery-middle Cerebral Artery Bypass.

CASE: Two years ago, annual magnetic resonance imaging for unruptured right internal carotid artery aneurysm of a 47-year-old woman detected a cerebral infarct in her right occipital lobe which was unknown etiology and antiplatelet therapy was initiated. She presented with sensory disorder of her left fingers 4 months ago. Infarction in right parieto-occipital cortex and severe stenosis of right middle cerebral artery was revealed. Her laboratory test was normal except remarkably high homocysteine value. Regardless of dual anti-platelet therapy, she suffered from repeated minor stroke and the stenosis was progressing. Therefore, right superficial temporal artery - middle cerebral artery bypass was undertaken. Aspirin and clopidogrel were withdrawn 1 week before the surgery. Two branches were anastomosed with 2 separate frontal M4 branches. Although patency was confirmed immediately after the anastomosis, thrombus formation was revealed after 10 minutes. We needed to perform removal of the thrombus and re-anastomosis twice. Intraoperative administration of aspirin and ozagrel alleviated thrombotic tendency. After surgery, antiplatelet therapy and supplementation with folate and vitamin B were performed. Her postoperative course was uneventful and patency of both anastomoses was confirmed. DISCUSSION: Controversy still exists regarding preoperative antiplatelet therapy before superficial temporal artery-middle cerebral artery bypass, and folates and B6-12 vitamins supplementation for hyperhomocysteinemia. Considering intraoperative thrombo tendency in our case, it is recommended to evaluate the homocysteine level before bypass surgery for intracranial stenosis especially for young patients or patients with unknown etiology. Before bypass surgery of the patient with hyperhomocysteinemia, continuation of perioperative antiplatelet drugs and supplementation with folates and B6-12 vitamins are mandatory.

[A Case of Dural Arteriovenous Fistula at the Craniocervical Junction with High Signal Intensity Localized to the Thoracic Spinal Cord on T2-weighted MRI].

An 82-year-old man presented with lower extremity weakness, paresthesia, and gait disturbance. At the previous hospital, spinal MRI had demonstrated a high-intensity area confined to the thoracic spinal cord on T2-weighted images and prominent dorsal venous flow voids that were suggestive of a thoracolumbar dural arteriovenous fistula(dAVF). Spinal digital subtraction angiography(DSA)failed to detect the shunt point. MRDSA of the head revealed a dAVF at the craniocervical junction(CCJ). Cranial DSA demonstrated feeders from the left vertebral artery and left radicular artery, a shunting point on the dura at the CCJ, and drainers into the anterior and posterior spinal veins descending to the sacral level. Surgery improved his symptoms, and the abnormal imaging findings were resolved. Observation of a dAVF at the CCJ with myelopathy is rare, and the diagnosis of this type of dAVF might be challenging. MRDSA might be a useful tool for detecting this uncommon dAVF.

[Anomalous Origin of the Ophthalmic Artery from the Anterior Cerebral Artery Associated with the Paraclinoid Internal Carotid Artery Aneurysm].

The ophthalmic artery usually arises from the supraclinoid portion of the internal carotid artery. Here, we present an extremely rare case of abnormal origin of the ophthalmic artery from the anterior cerebral artery associated with the paraclinoid internal carotid artery aneurysm. As the embryology of the ophthalmic artery is complex, this case provides additional insight into the variation of the ophthalmic artery.

[Orbital Compartment Syndrome Perhaps Secondary to Intra-Orbital Fluid Retention and Orbital/Palpebral Emphysema Following Frontotemporal Craniotomy for an Unruptured Cerebral Aneurysm:A Case Report].

A 58-year-old woman underwent left frontotemporal craniotomy for clipping of an unruptured cerebral aneurysm. A small defect was accidentally created in the orbital roof intraoperatively. The patient developed left eyelid edema and ocular pain after recovery from anesthesia. The following day, the eyelid edema worsened, and she had difficulty opening her eyes. On the 9th postoperative day, she noticed diminished visual acuity and diplopia in her left eye when she was able to spontaneously open her eyes. Ophthalmological evaluation revealed mild left visual loss, decreased light reflex, ophthalmoplegia, ptosis, and chemosis. Computed tomography(CT)/magnetic resonance imaging revealed left proptosis, optic nerve stretching, intra-orbital fluid retention, and orbital/palpebral emphysema. She was diagnosed with orbital compartment syndrome(OCS)and received conservative treatment;however, her visual acuity did not improve. OCS observed after cerebral aneurysm surgery is rare;to date, only 24 cases have been reported in the available literature. Although the mechanism of OCS after craniotomy is unclear, it may be attributed to ocular compression by a muscle flap or increased intra-orbital pressure secondary to venous congestion. In the present case, the left superior ophthalmic vein and cavernous sinus were not clearly visualized on CT angiography. Therefore, we concluded that the right superior ophthalmic vein and superficial facial veins underwent dilatation and served as collateral circulation of the left orbital venous system. We speculate that OCS occurred secondary to increased intra-orbital pressure, possibly caused by inflow of cerebrospinal fluid with air into the orbit through a small bone defect that was accidentally created during craniotomy in a setting of orbital venous congestion.

Resistance to the sympathoexcitatory effects of insulin and leptin in late pregnant rats.

KEY POINTS: Pregnancy increases sympathetic nerve activity (SNA), although the mechanisms responsible for this remain unknown. We tested whether insulin or leptin, two sympathoexcitatory hormones increased during pregnancy, contribute to this. Transport of insulin across the blood-brain barrier in some brain regions, and into the cerebrospinal fluid (CSF), was increased, although brain insulin degradation was also increased. As a result, brain and CSF insulin levels were not different between pregnant and non-pregnant rats. The sympathoexcitatory responses to insulin and leptin were abolished in pregnant rats. Blockade of arcuate nucleus insulin receptors did not lower SNA in pregnant or non-pregnant rats. Collectively, these data suggest that pregnancy renders the brain resistant to the sympathoexcitatory effects of insulin and leptin, and that these hormones do not mediate pregnancy-induced sympathoexcitation. Increased muscle SNA stimulates glucose uptake. Therefore, during pregnancy, peripheral insulin resistance coupled with blunted insulin- and leptin-induced sympathoexcitation ensures adequate delivery of glucose to the fetus. ABSTRACT: Pregnancy increases basal sympathetic nerve activity (SNA), although the mechanism responsible for this remains unknown. Insulin and leptin are two sympathoexcitatory hormones that increase during pregnancy, yet, pregnancy impairs central insulin- and leptin-induced signalling. Therefore, to test whether insulin or leptin contribute to basal sympathoexcitation or, instead, whether pregnancy induces resistance to the sympathoexcitatory effects of insulin and leptin, we investigated α-chloralose anaesthetized late pregnant rats, which exhibited increases in lumbar SNA (LSNA), splanchnic SNA and heart rate (HR) compared to non-pregnant animals. In pregnant rats, transport of insulin into cerebrospinal fluid and across the blood-brain barrier in some brain regions increased, although brain insulin degradation was also increased; brain and cerebrospinal fluid insulin levels were not different between pregnant and non-pregnant rats. Although i.c.v. insulin increased LSNA and HR and baroreflex control of LSNA and HR in non-pregnant rats, these effects were abolished in pregnant rats. In parallel, pregnancy completely prevented the actions of leptin with respect to increasing lumbar, splanchnic and renal SNA, as well as baroreflex control of SNA. Blockade of insulin receptors (with S961) in the arcuate nucleus, the site of action of insulin, did not decrease LSNA in pregnant rats, despite blocking the effects of exogenous insulin. Thus, pregnancy is associated with central resistance to insulin and leptin, and these hormones are not responsible for the increased basal SNA of pregnancy. Because increases in LSNA to skeletal muscle stimulates glucose uptake, blunted insulin- and leptin-induced sympathoexcitation reinforces systemic insulin resistance, thereby increasing the delivery of glucose to the fetus.

Arterial Spin Labeling Magnetic Resonance Imaging Can Identify the Occlusion Site and Collateral Perfusion in Patients with Acute Ischemic Stroke: Comparison with Digital Subtraction Angiography.

BACKGROUND AND OBJECTIVES: Determining the occlusion site and collateral blood flow is important in acute ischemic stroke. The purpose of the current study was to test whether arterial spin labeling (ASL) magnetic resonance imaging (MRI) could be used to identify the occlusion site and collateral perfusion, using digital subtraction angiography (DSA) as a gold standard. METHOD: Data from 521 consecutive patients who presented with acute ischemic stroke at our institution from January 2012 to September 2014 were retrospectively reviewed. Image data were included in this study if: (1) the patient presented symptoms of acute ischemic stroke; (2) MRI was performed within 24 h of symptom onset; and (3) DSA following MRI was performed (n = 32 patients). We defined proximal intra-arterial sign (IAS) on ASL as enlarged circular or linear bright hyperintense signal within the occluded artery and distal IAS as enlarged circular or linear bright hyperintense signals within arteries inside or surrounding the affected region. The presence or absence of the proximal IAS and distal IAS were assessed, along with their inter-rater agreement and consistency with the presence of occlusion site and collateral flow on DSA images. RESULTS: The sensitivity and specificity for identifying occlusion site with ASL were 82.8 and 100%, respectively. Those for identifying collateral flow with ASL were 96.7 and 50%, respectively. The inter-rater reliability was excellent for proximal IAS (κ = 0.92; 95% CI 0.76-1.00) and substantial for distal IAS detection (κ = 0.78; 95% CI 0.38-1.00). CONCLUSIONS: Proximal IAS and distal IAS on ASL imaging can provide important diagnostic clues for the detection of arterial occlusion sites and collateral perfusion in patients with acute ischemic stroke.

Biomarkers of Cardiac Dysfunction as Risk Factors in Cryptogenic Stroke.

BACKGROUND: It is unclear whether biomarkers of cardiac dysfunction are associated with cryptogenic stroke (CS). METHODS: We retrospectively evaluated consecutive ischemic stroke patients. Patients underwent transthoracic echocardiography to evaluate left atrial diameter and the peak transmitral filling velocity/mean mitral annular velocity during early diastole (E/e'). Patent foramen ovale (PFO) and left atrial appendage flow velocity were evaluated by transesophageal echocardiography. We compared clinical characteristics and biomarkers of cardiac dysfunction (brain natriuretic peptide [BNP], left atrial diameter, E/e', and left atrial appendage flow velocity) between CS or CS without large PFO and other causative stroke subtypes. RESULTS: Among 1,514 patients with ischemic stroke, 264 patients were classified as having CS. Of these, transesophageal echocardiography revealed 27/158 (17%) large PFOs. In comparison, for the noncardioembolic stroke group, which consisted of large artery and small vessel subtypes, patients with CS without large PFO had higher log10 BNP (adjusted OR 2.70; 95% CI 1.92-3.78; p < 0.001), higher log10 E/e' (3.41; 1.21-13.15; p = 0.019), and lower left atrial appendage flow velocity (0.98; 0.97-1.00; p = 0.031). Left atrial diameter was similar for noncardioembolic stroke and CS without large PFO (p = 0.380). Cutoff values of BNP, E/e', and left atrial appendage flow velocity capable of distinguishing CS without large PFO from noncardioembolic stroke were 65.0 pg/mL (sensitivity 55.3%; specificity 70.9%), 13.0 (45.5%; 68.0%), and 46.0 cm/s (37.1%; 87.5%), respectively. CONCLUSION: Patients with CS without large PFO could have biomarkers of cardiac dysfunction.

[Progression of Endovascular Treatment for Acute Ischemic Stroke].

OBJECTIVE: Percutaneous transluminal recanalization(PTR)has been performed for more than 20 years and progressing because of the development of endovascular devices. However, the results have been changing dramatically since PTR was first introduced owing to dynamic social environments. Thus, we evaluated the progression of the treatment by reviewing the medical records of patients who received the treatment. MATERIALS AND METHODS: The present author has worked in three hospitals and performed PTR for 39 cases of acute ischemic stroke from 1996 to 1998. From 2012 to 2014, PTR was performed for 57 cases, and results were compared between the early and recent periods by using patient medical files and records. RESULTS: Elderly patients were treated with PTR in the recent period. The main target of PTR was the M1 segment of the middle cerebral artery in the early period. The internal carotid artery-to-posterior circulation ratio increased in the recent period. Regarding the methods of PTR, mechanical retrieval devices were mainly used in the recent period and resulted in a significantly more complete recanalization. The recovery rate based on the Glasgow outcome scale score increased, and the mortality rate decreased significantly in the recent period. CONSLUSIONS: Along with the development of endovascular devices, the results of PTR have been improving.

[Surgery for a Refractory Chronic Subdural Hematoma Using an Exoscope:A Technical Case Report].

Burr hole irrigation and drainage is effective in most cases of chronic subdural hematoma(CSDH). However, we sometimes encounter refractory cases that need further procedures or other interventions. Here we report a case with a disturbance of consciousness and left hemiparesis. CT of the head showed a right CSDH, which recurred three times in spite of repeated burr-hole irrigation surgeries. We performed a mini-craniotomy and evacuation of the hematoma under the exoscope to remove the hematoma effectively. The post-operative course was uneventful and no recurrence was found at the last follow up. A mini-craniotomy with an exoscope might be a useful option for treating cases of refractory CSDH.

[Open Surgery Following Transarterial Embolization for Cavernous Sinus Dural Arteriovenous Fistula].

Cavernous sinus(CS)dural arteriovenous fistula with cortical venous drainage often have a malignant presentation and require urgent treatment. Endovascular embolization is the primary treatment of choice, but failure to catheterize the CS may occur due to vessel tortuosity, hypoplasia, or stenosis. In the absence of venous access to the lesion, a careful surgical approach should be considered. Here we describe a patient who underwent open surgery following an unsuccessful transvenous embolization due difficulties in venous access.

[Middle Cerebral Artery Fenestration with M2 Fusion Detected during Aneurysm Clipping:A Case Report].

We report a unique case of middle cerebral artery fenestration with M2 fusion detected during an aneurysm clipping. A 72-year-old woman was diagnosed with an unruptured aneurysm of the right middle cerebral artery, and middle cerebral artery fenestration with M2 fusion was detected during the aneurysm clipping surgery. It was difficult to identify this unusual vascular anomaly before the surgery. Therefore, neurosurgeons should be cautious of such hidden vascular anomalies and be prepared for the possible complications during surgery.