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Minimum wall shear stress (Min-WSS) points may be associated with wall instability of unruptured cerebral aneurysms. We aimed to investigate the relationship between the locations of Min-WSS points and their underlying intra-aneurysmal flow structure patterns in unruptured cerebral aneurysms using four-dimensional (4D) flow magnetic resonance imaging (MRI).Min-WSS points and the intra-aneurysmal flow structure patterns were identified in 50 unruptured aneurysms by 4D flow MRI.The Min-WSS points were located around a vortex core tip in 31 (62.0%) aneurysms and on an intra-bleb vortex center in 7 (14.0%). Sixteen (32.0%) aneurysms had the Min-WSS points on the aneurysmal apex, and in 24 (48.0%) were on the neck. The Min-WSS values of aneurysms with the Min-WSS points on an intra-bleb flow were significantly lower than those of the other groups (P = 0.030). Aneurysms with the Min-WSS points on the neck had significantly higher Min-WSS values than the other aneurysms (P = 0.008).The location of the Min-WSS point was corresponding to the vortex core or center in 76% of all aneurysms. The underlying intra-aneurysmal flow structure and location of the Min-WSS point affect the Min-WSS value. Further studies are needed to characterize Min-WSS points to identify aneurysms with a higher risk of wall instability.

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.

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.

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.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.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).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.

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 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 Conclusion Use of PD to predict recurrence after coil embolization can be clinically relevant.

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.

Background Symptomatic intramedullary arachnoid cysts are rarely observed lesions, particularly in the pediatric age group. Treatment includes cyst fenestration or resection of the cyst wall, and recurrence after surgery has never been reported. We report a rare case of a spinal intramedullary arachnoid cyst, which recurred after cyst fenestration and required reoperation after a certain period. Case Description A 4-year-old boy presented to our hospital with tetraparesis and bladder and rectum disorder. A cystic intramedullary lesion in the cervical spinal cord was detected in preoperative imaging. An emergency fenestration of cyst was performed, and his symptoms were resolved immediately. One month after the operation, the symptoms and cyst recurred. The symptoms improved in the natural course without reoperation. However, the cyst increased in size and the symptoms recurred after 27 months from the first relapse and the cyst was removed urgently. The diagnosis was an arachnoid cyst. After the reoperation, the cyst has disappeared and not recurred. Conclusions To the best of our knowledge, this is the first report of recurrence of an intramedullary arachnoid cyst. This case indicates the importance of considering the resection of cyst wall as possible because of the probability of cyst recurrence after fenestration, while careful observation is the option in the short term, especially for children or high-risk cases.

Background: In coil embolization, a high volume embolization ratio prevents recanalization that may require retreatment. However, patients with a high volume embolization ratio may also require retreatment. Patients with inadequate framing with the first coil may experience recanalization of the aneurysm. We analyzed the relationship between embolization ratio of the first coil and recanalization requiring retreatment. Methods: We reviewed data from 181 patients with unruptured cerebral aneurysms who underwent initial coil embolization between 2011 and 2021. We retrospectively analyzed the correlation between neck width, maximum aneurysm size, width, aneurysm volume, volume embolization ratio of the framing coil (first volume embolization ratio [1st VER]), and final volume embolization ratio (final VER) of cerebral aneurysms in patients and their retreatment. Results: Recanalization requiring retreatment was observed in 13 patients (7.2%). The factors related to recanalization were neck width, maximum aneurysm size, width, aneurysm volume, and 1st VER, but not the final VER. Multivariate analysis of the five factors showed a significant difference in the 1st VER (P = 0.002). The cutoff value for recanalization was a 1st VER of 5.8%. There were 162 cases with a VER ≥ 20% or higher, and the same analysis yielded similar results. Conclusion: The 1st VER was significantly correlated with recanalization of cerebral aneurysms requiring retreatment. In coil embolization of unruptured cerebral aneurysms, it is important to achieve an embolization rate of at least 5.8% using a framing coil to prevent recanalization.

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.

OBJECTIVE The spatiotemporal instability of intra-aneurysmal vortex flow may be associated with unruptured cerebral aneurysm rupture. We identified morphological factors that affect intra-aneurysmal vortex core patterns classified based on the instability on four-dimensional (4D) flow magnetic resonance imaging (MRI) and determined cutoff values for the factors to discriminate unstable core patterns. METHODS We classified vortex core patterns of 40 unruptured aneurysms on 4D flow MRI into stable, stable with a flapping tip, continuously deforming wave-or-coil-like, and non-visualized. We statistically compared nine morphological parameters among aneurysm groups with individual patterns. RESULTS The vortex cores were stable (n = 16) (group A), stable with a flapping tip (n = 15) (group B), wave-or-coil-like (n = 7) (group C), and non-visualized (n = 2) (group D). Since there were no statistically significant differences between groups A and B, we compared the difference between the groups A and B and the other groups. Multivariate logistic regression analyses found that size ratio (SR) was an only independently significant parameter (p

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 p 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.

金沢大学附属病院脳神経外科, Background and purpose: Hemodynamic impairments are considered risk factors of cerebral hyperperfusion after carotid artery stenting (CAS); measurement by Single-photon emission computed tomography (SPECT) using a subjective region of interest (ROI) method lacks consistency and reproducibility. Materials and methods: The present study compared objective perfusion analysis (stereotactic extraction estimation [SEE] method) with the ROI method for preoperative SPECT to predict the hyperperfusion phenomenon (HPP) after CAS. Preoperative resting asymmetry index (cerebral blood flow [CBF] ratio from the affected to unaffected hemisphere) and cerebrovascular reactivity (CVR) to acetazolamide were measured by N-isopropyl-p-[123I]-iodoamphetamine SPECT using the SEE and ROI method in 84 patients. CBF was also measured the day after CAS. Perfusion data with the highest area under the curve (AUC) by receiver-operating characteristic (ROC) analysis was considered a perfusion risk factor of HPP. Multivariate analyses for clinical characteristics and perfusion risk factors were performed to determine predictors of HPP. Results: The HPP was observed in 10 patients (11.9%). Female sex, contralateral stenosis, and degree of stenosis were significantly associated with HPP development on univariate analysis, and symptomatic stenosis was not found to be a significant factor. On SPECT analysis, CVR in the MCA area by SEE method had the highest AUC (0.981). Multivariate analysis showed that CVR in the MCA area was a significant predictor of HPP (P = 0.041). To predict hyperperfusion, the ROC curve of the CVR showed a cutoff value of –0.60%, sensitivity of 94.6%, and specificity of 100% (P < 0.001). Conclusions: Objective SEE method had better a predictive capability than ROI method to identify risk of hyperperfusion after CAS. © 2018 Elsevier Masson SAS, Embargo Period 12 months

An unruptured aneurysm was incidentally found in the right middle cerebral artery in a 67-year-old woman. During an attempt to turn the temporalis muscle for surgical clipping, systolic blood pressure suddenly increased. After opening the dura mater, we found a subarachnoid hemorrhage and severe brain swelling. We promptly expanded the craniotomy area to reach the aneurysm while pulling part of the frontal lobe to apply a clip. We retrospectively analyzed the aneurysm using computational fluid dynamics. Our analysis suggests that the rupture of the aneurysm occurred at a location with very low wall shear stress.

Prediction of the rupture risk is critical for the identification of unruptured cerebral aneurysms (UCAs) eligible for invasive treatments. The size ratio (SR) is a strong morphological predictor for rupture. We investigated the relationship between the inflow hemodynamics evaluated on four-dimensional (4D) flow magnetic resonance (MR) imaging and the SR to identify specific characteristics related to UCA rupture. We evaluated the inflow jet patterns and inflow hemodynamic parameters of 70 UCAs on 4D flow MR imaging and compared them among 23 aneurysms with an SR ≧2.1 and 47 aneurysms with an SR ≦2.0. Based on the shape of inflow streamline bundles with a velocity ≧75% of the maximum flow velocity in the parent artery, the inflow jet patterns were classified as concentrated (C), diffuse (D), neck-limited (N), and unvisualized (U). The incidence of patterns C and N was significantly higher in aneurysms with an SR ≧2.1. The rate of pattern U was significantly higher in aneurysms with an SR ≦2.0. The maximum inflow rate and the inflow rate ratio were significantly higher in aneurysms with an SR ≧2.1. The SR affected the inflow jet pattern, the maximum inflow rate, and the inflow rate ratio of UCAs. In conjunction with the SR, inflow hemodynamic analysis using 4D flow MR imaging may contribute to the risk stratification for aneurysmal rupture.

BACKGROUND AND PURPOSE: The complexity and instability of the vortex flow in aneurysms are factors related to the rupture risk of unruptured cerebral aneurysms. We identified aneurysm vortex cores on 4D flow MR imaging and examined the relationship of these factors with the characteristics of cerebral aneurysms. MATERIALS AND METHODS: We subjected 40 aneurysms (37 unruptured, 3 ruptured) to 4D flow MR imaging. We visualized streamlines with velocities below the threshold—that is, a percentage value of the aneurysm maximum inflow velocity—and progressively decreased the threshold to identify vortex cores as thin, streamline bundles with minimum velocities. Complexity and stability were compared in aneurysms with a smooth surface and those with blebs or daughter sacs. RESULTS: The threshold for visualizing vortex cores ranged from 3% to 13% of the maximum inflow velocity. Vortex cores could be visualized in 38 aneurysms; in 2, they were not visualized through the cardiac cycle. A simple flow pattern (single vortex core) was identified in 27 aneurysms; the other 13 exhibited a complex flow pattern. The cores were stable in 32 and unstable in 8 aneurysms. Significantly more aneurysms with-than-without blebs or daughter sacs had a complex flow pattern (P = .006). Of the 3 ruptured aneurysms, 1 aneurysm had an unstable vortex core; in the other 2, the vortex core was not visualized. CONCLUSIONS: The identification of vortex cores on 4D flow MR imaging may help to stratify the rupture risk of unruptured cerebral aneurysms.

Background There is a lack of information on the natural history of asymptomatic carotid artery stenosis (AsymCS) associated with cardiovascular diseases that require surgery. The aim of this study was to investigate risk factors for postoperative ipsilateral ischemic stroke and all-cause mortality after cardiovascular surgery in patients with AsymCS. Methods Among 2158 patients who underwent cardiovascular surgery, 150 patients with AsymCS who didn't undergo carotid revascularization were included. The relationships between preoperative factors, including carotid intraplaque hemorrhage (IPH), and postoperative ipsilateral ischemic stroke and all-cause mortality were analyzed retrospectively. Results During the median follow-up of 1087 days of 150 patients with 19 IPH, 12 (8.0%) and 21 (14.0%) encountered ipsilateral infarction and all-cause mortality, respectively. Multivariable Cox regression analyses indicated that IPH was significantly predictive of both ipsilateral infarction (hazard ratio [HR] 21.31, 95% confidence interval [CI], 4.98–91.17; P ≤.001) and all-cause mortality (HR 4.64, 95% CI, 1.61–13.34; P = .004). Another significant factor was peak systolic velocity for ipsilateral infarction with the cutoff velocity of 227 cm/s by the receiver-operating characteristic curve. Conclusions In this cohort of patients with AsymCS undergoing cardiovascular surgery, IPH had a close connection with a high risk of both postoperative ischemic stroke and mortality after cardiovascular surgery.

Stereotactic brain biopsy using a navigation system is minimally invasive because it can be performed under local anesthesia. However, there are problems due to the localization and accessibility of the tumor and instability of the airway under sedation. This study aimed to examine the differences in safety and surgical time between the supine and lateral position.This study included 25 cases which underwent navigation-guided brain biopsies from May 2015 to March 2018 in the Kanazawa University Hospital. We compared tumor localization, operation time, standby time, intraoperative difficulties, and final diagnosis acquisition rates between the supine and lateral positions. Puncture sites were then examined by visualizing all biopsy trajectories simultaneously on a three-dimensional cerebral template.Biopsies of the tumor in all cerebrum lobes were possible in the lateral position. There were no significant differences in operating time or standby time between the supine and lateral positions. One case in the spine position required sedation by an anesthesiologist due to body movement, but there were no difficulties in any cases of lateral positioning. The final diagnosis acquisition rate was 100% in all cases. In the lateral position, stable breathing was maintained because the head and the trunk axes remined in the same line.Stereotactic brain biopsy in the lateral position can be safer and more useful than in the supine position under local anesthesia.

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).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.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; p0.001). Furthermore, there was a moderate correlation between the velocity ratios measured by CFD and 4D flow MRI (r = 0.559; p = 0.008).Inflow hemodynamics evaluated by CFD analysis and 4D flow MRI showed good correlations in inflow jet pattern, inflow rate ratio, and velocity ratio.

Background: Pituicytoma is a rare benign tumor of the neurohypophysis or hypophyseal stalk. Endocrinological abnormalities derived from this tumor are even rarer. Although three cases of pituicytoma with elevated plasma adrenocorticotropic hormone (ACTH) have been reported previously, the etiological mechanisms remain unknown. Case Description: We present a 47-year-old woman who was referred to a hospital complaining of headache. On investigation using magnetic resonance imaging (MRI), a tumor was detected in the sellar region. Elevation of basal ACTH and serum cortisol was identified, suggesting an ACTH-producing pituitary adenoma. However, physical findings and results of other hormonal examination showed no evidence of Cushing disease. The tumor had been detected incidentally eight years earlier when MRI was performed, and showed considerable enlargement on this consultation. Endoscopic endonasal transsphenoidal surgery was performed in order to remove the tumor completely. The histopathological diagnosis was pituicytoma. The patient’s postoperative clinical course was excellent, and both ACTH and cortisol levels returned to normal following surgery. Conclusions: It appears that ACTH was being secreted from the tumor cells. We discuss the possible mechanism of ACTH elevation in cases of pituicytoma.

Background Hyperperfusion syndrome associated with aneurysm surgery is rare. The occurrence of the syndrome after trapping with high-flow bypass has not been described previously. Herein, we present a case of the syndrome that occurred after trapping with high-flow bypass of an unruptured giant paraclinoid internal carotid artery (ICA) aneurysm. Case Description The patient was a 68-year-old woman with progressive loss of vision in her left eye. After a diagnosis of left giant ICA aneurysm, she underwent successful trapping with high-flow bypass. No new neurologic deficits were observed after surgery. Computed tomography on the same day and magnetic resonance imaging on the next day revealed no hemorrhage or infarction. The patient had a headache and transit motor aphasia on postoperative day (POD) 8. Arterial spin-labeling magnetic resonance perfusion imaging on the same day and single photon emission CT on POD 10 demonstrated hyperperfusion in the left cerebral cortex. The symptoms gradually improved over a week, and she had no new neurologic deficits when discharged from hospital. Conclusions This report suggests that hyperperfusion syndrome after trapping with high-flow bypass, although rare, should be considered in patients with giant aneurysm if they present with headache and neurologic deficits after a delay.

BACKGROUND Hemodynamic factors play a crucial role in the recurrence of intracranial aneurysms after coiling. However, the strongest factor for predicting recurrence remains unclear because each risk factor has been investigated and reported separately. OBJECTIVE To clarify the strongest predictor of recurrence with computational fluid dynamics (CFD). METHODS Using pretreatment patient-specific 3-dimensional rotational angiography data of 50 internal carotid artery (ICA) aneurysms (7 recanalized, 43 stable) treated with endovascular coiling, we created a precoiling model and a virtual postcoiling model produced by manually cutting the aneurysm by the flat plane corresponding to the virtual coil surface. We conducted CFD analysis to investigate inflow dynamics in the precoiling model and pressure difference and wall shear stress on the virtual coil surface. The pressure difference was calculated by subtracting average pressure at the proximal ICA from the maximum pressure at the coil surface and dividing by dynamic pressure at the proximal ICA for normalization. We compared hemodynamic parameters in both models between recanalized and stable aneurysms. RESULTS Compared with stable aneurysms, recanalized aneurysms showed a significantly larger inflow area and higher inflow rate in the precoiling model (P = .016, .028), and higher pressure difference at the coil surface in the postcoiling model (P

Background We report the concurrence of a spinal dural arteriovenous fistula (DAVF) and multiple perimedullary arteriovenous fistulas (PAVFs) presenting with subarachnoid hemorrhage (SAH). Moreover, the bleeding site was detected 1 month after onset. Case description A 56-year-old man was admitted to our hospital with an SAH. A DAVF and two PAVFs were detected at the C2 level by two rounds of digital subtraction angiography. The source of bleeding, an aneurysm on the feeding artery of PAVF, was detected at the second angiogram, which was performed 1 month after the onset of SAH. The aneurysm was not demonstrated at initial angiogram because of thrombosis in the aneurysm. The DAVF was interrupted by transarterial embolization, and the two PAVFs were subsequently treated with surgery. Conclusion A part of the whole AVFs or the source of bleeding may be invisible in the acute stage just after hemorrhage. Repeated angiography is necessary to diagnose such complex AVFs especially in case of an SAH and treatment should be performed during the subacute stage.

Delayed coil migration after endovascular treatment with detachable coils, particularly several months after treatment, is extremely rare. In this report, the authors describe a 77-year-old female in whom delayed coil migration to the anterior cerebral artery and posterior communicating artery (PCoA) developed 3 months after an uncomplicated aneurysm embolization. The patient was successfully retreated with a closed-cell stent. Computational fluid dynamics (CFD) revealed high wall shear stress (WSS) and multiple vortices in the residual cavity of the initially treated aneurysm. CFD could be useful to detect and predict this complication, and a stent-assisted technique could be an important treatment option.

Background: During endovascular treatment of an aneurysm, the importance of the initial coil volume for facilitating tight packing is unclear. We retrospectively studied the relationships between initial packing density (PD; initial coil volume divided by aneurysm volume), final PD (volume of all coils divided by aneurysm volume). Methods: We reviewed 105 aneurysms in 98 patients who underwent endovascular coiling between April 2011 and March 2014. The initial coil was defined as the first coil in the single-catheter method and the first 2 coils in the double-catheter method. The patient data were divided into groups with or without a final PD ≥20%, and the significant predictors of a final PD ≥20% were determined using multivariable logistic regression. The optimal cutoff value for the initial PD was determined using a receiver operating characteristic curve. Results: Of 105 aneurysms, 56 and 49 were treated with single- and double-catheter methods, respectively. Statistically significant differences in rupture status, neck size, dome/neck ratio, and initial PD were observed between aneurysms with and without a final PD ≥20% (all P < 0.05). Multivariate analysis showed that initial PD (P = 0.025; odds ratio, 1.22) and rupture status (P = 0.002; odds ratio, 0.19) were significantly associated with a final PD ≥20%. Using receiver operating characteristic curve analysis, the cutoff points of initial PD to achieve a final PD ≥20% were 8.0% and 10.0% in single- and double-catheter groups, respectively. Conclusions: Initial PD appears to be a critical factor for achieving tight packing. © 2016 Elsevier Inc. All rights reserved., Embargo Period 12 months

【目的】左総頚動脈（CCA）狭窄症に対するステント留置術の際にガイディングシースの保持を右上腕動脈経由のGooseNeck Snareで行った症例を報告する．【症例】70歳，男性．一過性の右片麻痺で発見された症候性左CCA狭窄症に対してステント留置術を行った．狭窄病変とCCA起始部の距離が短いためガイディングシースを十分遠位まで挿入できなかった．そのため右上腕動脈経由のGooseNeck Snareでガイディングシースを保持してステント留置術を施行し得た．【結論】上腕動脈経由のGooseNeck Snareによる左CCAのガイディングシースの保持は有用であった．Objective: We report a case of left common carotid artery stenting in which the guide sheath was held in place by a GooseNeck Snare inserted from the right brachial artery. Case presentation: A 70-year-old man presented with transient right hemiparesis and symptomatic left common carotid artery stenosis. During carotid artery stenting, we were unable to insert the guide sheath into the distal site of the carotid artery because of the short distance between the origin of the carotid artery and the stenotic lesion. By holding the guide sheath in place using the GooseNeck Snare inserted from the right brachial artery, stenting was performed successfully. Conclusion: Transbrachial GooseNeck Snare was useful for stabilization of the guide sheath during left common carotid artery stenting.