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Objective: In this preliminary study, we investigated the value of fusion techniques by flat detector computed tomography based dual volume rotational angiography (DVRA) for the evaluation of the anatomical relationship of cavernous sinus dural arteriovenous fistula (CSDAVF) and assessed the possibility of transvenous target segment embolization., Methods: Twenty-six patients with CSDAVF supplied by multiple feeders underwent DVRA for each feeding large vessel separately. We assessed the anatomical relationship of feeders, fistula points, and venous drainage with 3 dual volume image fusion techniques. Transvenous embolization was targeted to the segment of fistulous point for preserving those not involved and reducing coil mass effect., Results: Dual vessel multi-planar reconstruction fusion technique could show which segment of the cavernous sinus supplied by feeding arteries. In the dual vessel volume rendering fusion technique, the association between feeding arteries, fistula points, and draining veins of 2 different vessels could be accurately identified in 3 dimensions. In addition, we could visualize the exact anatomical relationship between the components of CSDAVF and skull anatomy with the single vessel fusion technique. Based on various fusion images, target segment embolization was successfully performed in 8 patients. In this group, we achieved complete or near complete occlusion without complications, including cranial nerve palsy., Conclusions: Detailed anatomical information including accurate fistula point, specific feeding arteries, and draining veins could be obtained with various dual volume image fusion techniques. In addition, the target segment embolization of CSDAVF could be possible with understanding of the precise CSDAVF architectures., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective: We aimed to investigate risk factors for the recurrence of distal anterior cerebral artery (DACA) aneurysms after endovascular treatment (EVT)., Methods: The clinical and radiologic outcomes of DACA aneurysms treated with endovascular methods at a single tertiary hospital from September 2008 to December 2021 were retrospectively reviewed. We measured the angle between 2 distal branches of DACA aneurysms and categorized the angle as follows: 1) wide-angle (≥180°), and 2) narrow-angle type configuration (<180°). Univariate and multivariate analyses were performed to demonstrate the relationships between characteristics of DACA aneurysm and recurrence risk., Results: In total, 132 DACA aneurysms were treated in our institution. Among these, 47 DACA aneurysms after EVT were included in this study. Forty patients underwent coil embolization without stent, 7 for stent-assisted coil embolization. At the last follow-up (mean 30.2 ± 24.2 months), overall recurrence rate was 23.4% (n = 11). Recurrence rate of the wide-angle type (9 of 23, 39.1%) was significantly greater than narrow-angle type (2 of 24, 8.3%) (P = 0.041; odds ratio 8.174, 95% confidence interval 1.094-61.066). Irregular shape of the DACA aneurysm also showed significantly greater recurrence rate (P = 0.011; odds ratio 10.663, 95% confidence interval 1.701-66.838) after endovascular treatment., Conclusions: The wide-angle between 2 distal branches of DACA aneurysm and irregular shape might be independent risk factors for the recurrence after endovascular treatment for DACA aneurysms., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective: We aimed to compare the clinical and radiological outcomes of vertebral artery dissecting aneurysms (VADAs) stratified using different endovascular treatment methods., Methods: We retrospectively reviewed 116 patients with VADAs treated at a single tertiary institute between September 2008 and December 2020. We analyzed and compared the clinical and radiological parameters according to different treatment methods., Results: In total, 127 endovascular procedures were performed in 116 patients. We initially treated 46 patients with parent artery occlusion, 9 with coil embolization without stent, 43 with single stent with or without coil, 16 with multiple stents with or without coils, and 13 with flow-diverting stent. At the last follow-up (mean 37.8 ± 30.9 months), the complete occlusion rate (85.7%) was higher in the multiple-stent group than in the groups that received other reconstructive treatment methods. Moreover, the recurrence (0%) and retreatment (0%) rates were significantly lower in the multiple stent group (P < 0.001). The coil embolization-only group showed the highest recurrence (n = 5, 62.5%) and incomplete occlusion (n = 1, 12.5%) rates. The single-stent group showed higher recurrence (n = 9, 22.5%) and retreatment (n = 3, 7%) rates. Multivariate logistic regression analyses showed that coil embolization without stent placement (odds ratio = 172.76, 95% confidence interval = 6.83-4366.85; P = 0.002) was significantly associated with recurrence. At the last follow-up (mean, 42.1 ± 37.7 months), we achieved favorable clinical outcomes (modified Rankin Scale ≤2) in 106 of 127 patients., Conclusion: When treating VADAs, multiple stent placements may play a key role in achieving favorable long-term radiological outcomes., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objective: To assess clinical outcomes of ruptured vertebral artery dissecting aneurysms, focusing on comparing parent artery occlusion (PAO) with stent-assisted treatments, and to identify risk factors for unfavorable outcomes and postprocedural complications., Methods: This retrospective review included 36 ruptured vertebral artery dissecting aneurysms treated between February 2009 and April 2020. Treatment modalities included PAO without stent and stent-assisted treatments. Stent-assisted treatments included PAO with posterior inferior cerebellar artery (PICA) stenting and stent-assisted coiling. Univariate and multivariate analyses were conducted to evaluate risk factors for unfavorable outcomes and postprocedural complications., Results: Patients were treated with PAO only (24, 66.7%), PAO with PICA stenting (4, 11.1%), and PAO with stent-assisted coiling (8, 22.2%). There were only fusiform aneurysms with PICA involvement in the PAO with PICA stenting group. In the stent-assisted coiling group, 4 aneurysms incorporated PICA, and 4 aneurysms involved dominant vertebral artery. Old age (odds ratio [OR] = 1.25, 95% confidence interval [CI] = 1.01-1.56, P = 0.044) and poor Hunt-Hess grade (OR = 537.99, 95% CI = 6.73-42994.1, P = 0.005) were significantly associated with unfavorable clinical outcomes after a mean follow-up of 37.5 ± 32.8 months. Fusiform dilatation shape (OR = 15.97, 95% CI = 1.52-167.38, P = 0.021) and PICA involvement (OR = 13.71, 95% CI = 1.29-145.89, P = 0.030) were independent risk factors for ischemic complications., Conclusions: Unfavorable clinical outcomes were significantly related to old age and poor Hunt-Hess grade. There were no significant differences between treatment groups in clinical outcomes or ischemic complications. Stent-assisted treatments might be effective and safe methods for ruptured vertebral artery dissecting aneurysms., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: We aimed to compare clinical outcomes of acute ischemic stroke (AIS) due to internal carotid artery (ICA) occlusion following mechanical thrombectomy (MT), focusing on occlusion types., Methods: We retrospectively reviewed 67 AIS patients who had an ICA occlusion on computed tomography angiography and underwent MT in a single tertiary center. ICA occlusion types were categorized as (1) true cervical ICA (cICA) occlusion (true occlusion), (2) pseudo-occlusion of the cICA (pseudo-occlusion), and (3) distal ICA (dICA) occlusion. We compared the clinical characteristics and their outcomes according to the ICA occlusion type., Results: Fourteen patients were diagnosed with true occlusion, 32 with pseudo-occlusion, and 21 with dICA occlusion. The main etiologies were atherothrombotic in true occlusion (64.3%) and cardioembolic in pseudo-occlusion (81.3%) and dICA occlusion (71.4%) (P < 0.001). Pseudo-occlusion showed lower rates of successful reperfusion (37.5%, P = 0.009, 78.6% in true occlusion and 71.4% in dICA occlusion) and poor functional outcome at 3 months (18.8%, P = 0.037, 50% in true occlusion and 47.6% in dICA occlusion) with statistical significance. The infarction volume (169.4 ± 154.4 mL, P = 0.004, 29.2 ± 52.7 mL in true occlusion and 105.8 ± 13.4 mL in dICA occlusion) was significantly higher in pseudo-occlusion. On multivariate logistic analysis, pseudo-occlusion (odds ratio [OR]: 4.84, 95% confidence interval [CI] 1.02-22.87, P = 0.023) was an independent risk factor for poor reperfusion, which was significantly associated with a poor functional prognosis (OR: 22.04, 95% CI 1.99-243.83, P = 0.012)., Conclusions: Patients with pseudo-occlusion showed poorer clinical outcomes compared with other ICA occlusion types, possibly due to a poor reperfusion rate after MT., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Balloon-assisted coiling (BAC) is an endovascular treatment that may be associated with increased complications and thromboembolic events compared with other coiling techniques. We compared clinical outcomes of endovascular treatment (simple coiling, stent-assisted coiling, and BAC) in patients with unruptured intracranial aneurysms at the internal carotid artery and assessed risk factors that could cause cerebral infarction in patients who underwent BAC., Methods: We retrospectively reviewed the records of 528 patients with 544 aneurysms who underwent endovascular treatment for unruptured intracranial aneurysms between January 2013 and November 2019. Demographic features, clinical information, balloon inflation time, fetal posterior cerebral artery, anterior cerebral artery (ACA) variants, and angiographic results were analyzed to determine risk factors for cerebral infarction., Results: There were no significant differences among the 3 groups in terms of general characteristics. In the BAC group, 14 of 39 patients showed a significantly higher incidence of cerebral infarction on diffusion magnetic resonance imaging compared with the stent-assisted coiling (37/238) and simple coiling (21/267) groups (P < 0.001). There was no significant difference between the ACA variants (normal vs. hypoplasia or aplasia) and cerebral infarction in the simple coiling and stent-assisted coiling groups, but the proportion of aplasia or hypoplasia in the BAC group was significantly higher (P = 0.001)., Conclusions: There is a significant association between anatomic ACA variants and cerebral infarction occurrence after BAC. Identifying the variant of the anatomic ACA using digital subtraction angiography would help to predict cerebral infarction after BAC., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: We hypothesized that the immediate postoperative imaging features would be associated with early regression of flow-diverted aneurysms. We compared the imaging features from digital subtraction angiography and spin echo T2-weighted magnetic resonance imaging between those with early total regression and partial regression., Methods: A total of 30 consecutive patients with large and giant aneurysms were treated with pipeline embolization devices and divided into 2 groups according to the follow-up angiographic findings at 3-6 months. Of the 30 patients, 20 had had total or near total regression and 10 had had partial regression of the aneurysmal sac. The baseline characteristics, percent area of stagnated iodine contrast agent on anteroposterior and lateral angiographic views just after installation of the pipeline device, and median, minimal, and 10-percentile signal intensity of the aneurysmal sac on T2-weighted spin echo images 1 day after the procedure were compared between the 2 groups., Results: A comparison of the demographic data between the 2 groups showed no significant differences. The volume of the treated aneurysmal sac also did not differ significantly (2559.28 ± 3021.45 mm 3 vs. 2551.76 ± 6550.58 mm 3 ; P = 0.455). The total or near total regression group had a larger percent area of iodine stagnation on the lateral angiographic view compared with the partial regression group (52.26% vs. 23.35%; P = 0.002). The median, minimal, and 10-percentile signal intensity of the volume of interest were higher in the total or near total regression group than in the partial regression group (1.29 vs. 0.93 [P = 0.025]; 0.07 vs. 0.00 [P = 0.042]; 0.57 vs. 0.24 [P = 0.005])., Conclusions: The percent area of contrast media stagnation on lateral angiograms and the median, minimal, and 10th-percentile signal intensity of the volume of interest of treated aneurysmal sacs on T2-weighted images can be used to predict early regression of aneurysmal sacs., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objectives: To identify predictors of atherosclerotic change in aneurysms and parent arteries, and to retrospectively analyze outcomes from clipped aneurysms that showed atherosclerotic changes., Methods: Between May 2017 and April 2018, we collected a total of 151 clipping cases and reviewed records of operation videos to classify atherosclerosis by location (dome, neck of aneurysm, or parent artery). To identify predictors of atherosclerotic change in aneurysms, we analyzed baseline demographic characteristics, preoperative images, and Framingham Risk Scores (FRS). We also analyzed incomplete clipping cases according to atherosclerosis presence and location., Result: This study cohort included 110 women (mean age, 59.3 ± 7.1 years) and 41 men (mean age, 55.9 ± 9.6 years). Atherosclerotic change was seen in 77 cases. FRS, diabetes mellitus, and aneurysm size were identified as independent risk factors for atherosclerotic change in multivariate logistic regression analysis. There were 11 incomplete clipping cases (7.2%). Among the 30 cases with atherosclerotic change in the neck were 10 cases of incomplete clipping (P < 0.001)., Conclusions: FRS, diabetes mellitus, and aneurysm size as predictors of atherosclerosis in patients undergoing aneurysm surgery can help guide surgical decisions and performance., (Copyright © 2019. Published by Elsevier Inc.)

Background: The transvenous approach via the inferior petrosal sinus (IPS) is the most commonly used route to access cavernous sinus dural arteriovenous fistulas (CSDAVF). The facial (FV) or superficial temporal vein (STV) are alternatives in cases with IPS occlusion. However, navigation through the ophthalmic vein via FV or STV is difficult because of its specific anatomical features, such as abrupt angulations and tortuous course. Herein, we introduce a microwire looping method to overcome these obstacles, thus enabling access to cavernous sinus., Methods: We initially tried to navigate a microcatheter through the vein using a conventionally shaped microguidewire tip. If the traditional method failed, we made a single- or double-looped microguidewire. After anchoring the microguidewire, we pushed the microcatheter to add microcatheter tension and steered the microguidewire. Then, looping was formed and the looped microguidewire tip was easily passed through the abruptly angulated or tortuous vein., Results: This looping technique was applied in 7 CSDAVFs (4 were through FV and 3 were through STV) that were unable to pass through IPS. In all cases, a total of 10 microcatheters (4 with single microcatheter and 3 with double microcatheters) successfully approached CSDAVF, achieving effective transvenous coil embolization. The clinical and radiologic outcomes were excellent in all patients. There was 1 postprocedural cranial nerve palsy without any morbidity or mortality., Conclusions: Making a microguidewire loop to pass through abruptly angulated or tortuous head and neck veins might be an effective and safe alternative for when catheterization is not feasible by the traditional method., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Although transarterial embolization (TAE) with Onyx has become popular for the treatment of dural arteriovenous fistulas (DAVFs), transvenous embolization (TVE), surgery, and radiosurgery have continued to have a role. The aim of the present study was to compare the treatment outcomes stratified by the different treatment modalities., Methods: The data from 92 patients with DAVFs treated from January 2009 to June 2018 were retrospectively reviewed. The treatment strategies were decided by a multidisciplinary team according to the patient's clinical status and angiographic findings. The clinical and radiologic data were analyzed and correlated with the treatment modality., Results: A total of 101 procedures were performed in the 92 patients. TAE, TVE, surgery, and radiosurgery were performed in 31, 49, 12, and 9 procedures, respectively. Complete and near complete occlusion was achieved in 13 cases treated with TAE (41.9%), 41 treated with TVE (83.7%), and 10 with surgery (83.3%), as shown on immediate postprocedural angiography (P < 0.001). Retreatment was needed in 9 patients in the TAE group and none in the TVE or surgery groups (P < 0.001). Surgery (n = 1), TVE (n = 3), TAE (n = 1), and radiosurgery (n = 4) were used for patients requiring retreatment. At the last follow-up examination (mean, 26.5 ± 23.9 months), 66 of 72 DAVFs (91.6%) showed angiographic complete occlusion. Clinically, the initial symptoms had disappeared or improved in 87 of 90 patients (96.7%) at the last follow-up evaluation (mean, 26.4 ± 26.8 months)., Conclusions: Even in the Onyx era, other treatment modalities still have important roles, as shown in the present study. Therefore, the selection of the appropriate treatment modality should be individualized by the angiographic findings and clinical symptoms., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objective: To determine clinical and radiologic outcomes of vertebral artery dissecting aneurysms involving posterior inferior cerebellar artery according to different types of endovascular treatment., Methods: This study included 18 vertebral artery dissecting aneurysms (6 ruptured and 12 unruptured) involving posterior inferior cerebellar artery treated from January 2009 to December 2016. Treatments were multiple stenting, stent-assisted coil embolization, vertebral artery trapping with vertebral artery-posterior inferior cerebellar artery stenting, and Pipeline embolization. Clinical and radiologic information were obtained from retrospective chart review and radiologic review., Results: Subarachnoid hemorrhage was diagnosed initially in 6 of 18 patients, and infarction was diagnosed initially in 2 patients. Multiple stenting was performed in 4 patients, including 1 (25%) who had cerebellar infarction and 1 (25%) who had recurrence. Stent-assisted coil embolization was performed in 8 patients, including 1 (12.5%) who had postoperative cerebellar infarction and 2 (25%) who had recurrence. Vertebral artery trapping with vertebral artery-posterior inferior cerebellar artery stenting was performed in 4 patients, including 1 (25%) who had postoperative cerebellar infarction. There was no recurrence (0%). Pipeline embolization was performed in 2 patients, including 1 (50%) who had recurrence. There was no postoperative infarction (0%). No subarachnoid hemorrhage occurred during follow-up. Deterioration in modified Rankin Scale score was found only in the stent-assisted coil embolization group (1/8; 12.5%)., Conclusions: Vertebral artery trapping with vertebral artery-posterior inferior cerebellar artery stenting showed the lowest rate of aneurysm recurrence with high rate of minor infarction and favorable neurologic outcome. Stent-assisted coil embolization showed high recurrence rates with possible fatal disabling infarction., (Copyright © 2018. Published by Elsevier Inc.)

A new Low-profile Visualized Intraluminal Support device (LVIS Blue) is a braided stent that provides a higher degree of metal coverage. This stent may be beneficial for complete obliteration of an aneurysm due to not only its support of a higher occlusion rate using coils inside of the aneurysm but also its flow-diverting effect. We introduce and describe a new flow-diversion technique using an LVIS Blue stent within an Enterprise stent for patients with vertebral artery (VA) dissecting aneurysms. A 6-Fr guiding catheter was positioned in the ipsilateral VA. A microcatheter with an inner diameter of 0.021 inches was navigated and positioned across the dissecting segment of the VA. An Enterprise stent was then deployed and used to cover the dissecting segment by pushing the pusher wire of the stent while simultaneously unsheathing the microcatheter. The microcatheter was navigated along the remaining pusher wire to the distal VA through the Enterprise stent. An LVIS Blue stent was introduced and positioned such that it overlapped the previous stent in order to divert blood flow away from the dissecting segment. We present a case in which this technique was used to successfully obliterate a dissecting aneurysm while maintaining the VA patency with vessel wall remodeling. The LVIS Blue stent-within-an-Enterprise stent technique may be an effective treatment option for patients with VA dissecting aneurysms as an alternative technique to flow diverters., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Whether intravenous thrombolysis (IVT) before mechanical thrombectomy (MT) provides additional benefits remains controversial. We aimed to compare clinical and radiologic outcomes between IVT+MT and MT alone groups., Methods: We retrospectively reviewed the clinical and radiological features of patients from the prospectively collected database who sustained anterior circulation stroke due to large vessel occlusion (LVO) and were treated with MT within 8 hours of symptom onset. We compared rates of successful reperfusion, functional independence and mortality at 90 days, and symptomatic intracranial hemorrhage (sICH) as clinical endpoints between the 2 groups., Results: The 81 patients included in this study included 38 (46.9%) in the MT alone group (mean age, 72.6 ± 14.1 years; 17 males [44.7%]) and 43 in the IVT+MT group (mean age, 68.9 ± 12.8 years; 29 males [67.4%]). There were no significant differences in patient baseline characteristics between the 2 groups except for a male predominance in the IVT+MT group. The mean interval from onset to groin puncture (221.6 ± 110.5 minutes vs. 204.7 ± 63.7 minutes; P = 0.472) and the rate of successful reperfusion rate (thrombolysis in cerebral infarction 2b/3, 60.5% vs. 58.1%; P = 0.827) did not differ significantly between the MT and IVT+MT groups. The rate of favorable functional outcome, as determined by a modified Rankin Scale score 0-2 (36.8% vs. 51.2%; P = 0.263) and mortality at 90 days (18.4% vs. 9.3%; P = 0.332), and the rate of sICH (5.3% vs. 4.6%; P = 1.000) were also not significantly different between the 2 groups., Conclusions: This study suggests that previous IVT might not facilitate successful reperfusion and favorable functional outcomes in patients with anterior circulation stroke treated with MT. MT alone can be a safe and effective treatment modality in patients who are ineligible for IVT for various reasons., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: The purpose of this study was to investigate the incidence and characteristics of remote intracerebral hemorrhage (ICH) after endovascular treatment (EVT) of unruptured intracranial aneurysms (UIAs)., Methods: Between March 2007 and September 2015, 11 patients with remote ICH from a series of 2258 consecutive patients with 2597 UIAs treated via EVT were identified. Baseline demographic characteristics, medical history, radiologic imaging data, characteristics of remote ICH, and clinical outcomes were retrospectively reviewed. The characteristics of patients with remote ICH were compared with those of patients without remote ICH., Results: All hematomas were single lesions located in the subcortical white matter as lobar-type in 9 patients (81.8%) and in the basal ganglia in 2 patients (18.2%). Events occurred mostly within 1 week and up to 3 weeks after EVT. Hematoma was located on the ipsilateral side in 8 patients (72.7%) and in the contralateral side in 3 patients (27.3%). Compared with patients without remote ICH, there were more aneurysms located on the internal carotid artery (ICA) (P = 0.041), more patients treated with stents (P < 0.001), more patients with hypertension (P = 0.026), and poorer clinical outcomes at discharge (P < 0.001) for patients with remote ICH., Conclusions: The incidence of remote ICH after EVT of UIAs was 0.46%. This event occurred mostly in patients with stents, hypertension, and UIAs on the ICA. It presented mostly as an ipsilateral lobar-type hemorrhage within 1 week after the procedure. This complication should not be neglected because of its poor clinical outcomes., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: To report our experiences in microsurgical clipping of unruptured middle cerebral artery (MCA) bifurcation aneurysms and to evaluate the incidence of and risk factors for procedure-related complications., Methods: The study comprised 416 patients treated between March 2003 and February 2014. All patients met the following criteria: 1) microsurgical clipping of an unruptured MCA bifurcation aneurysm was performed, and 2) clinical and radiographic follow-up data were available including preoperative digital subtraction angiography. The incidence of and risk factors for procedure-related complications were retrospectively evaluated., Results: Procedure-related complications occurred in 15 (3.6%) patients, including asymptomatic complications in 10 (2.4%) patients and symptomatic complications in 5 (1.2%) patients. Multivariate logistic regression analysis showed that posteroinferior projection of the aneurysm (odds ratio = 2.814, 95% confidence interval = 0.995-6.471, P = 0.042), distance between the internal carotid artery bifurcation and the MCA bifurcation (Dt) in a linear line (odds ratio = 1.813, 95% confidence interval = 0.808-6.173, P = 0.043), and horizontal angle between the vertical line to the base of the skull and Dt (odds ratio = 2.046, 95% confidence interval = 1.048-10.822, P = 0.048) were independent risk factors for procedure-related complications., Conclusions: When performing clipping of unruptured MCA bifurcation aneurysms, the procedure-related complication rate was 3.6%. Patients with MCA bifurcation aneurysms with posteroinferior projection, shorter Dt, and larger horizontal angle may be at a higher risk of procedure-related complications when performing microsurgical clipping., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Objective: Advances in endovascular treatment (EVT) have greatly improved the treatment outcomes of paraclinoid aneurysms. However, EVT had the shortcoming of durability and thromboembolic complications. As well, surgical treatment of paraclinoid aneurysms is still challenging due to the complexity of adjacent structures. The objective of this study is to report our experience with a combined surgical and endovascular treatment of unruptured paraclinoid aneurysms based on the location of aneurysms., Methods: A retrospective review was conducted of 185 cases of unruptured paraclinoid aneurysms that underwent surgical or endovascular treatment between September 2008 and August 2012. Thirty-one aneurysms (16.8%) were treated by microsurgery and 154 (83.2%) were treated by EVT. Fifty aneurysms (27.0%) were classified to the dorsal group and 135 (73%) were classified to the non-dorsal group., Results: Twenty of 50 dorsal group aneurysms (40%) were treated by microsurgery while 124 of 135 non-dorsal group aneurysms (91.9%) underwent an EVT. The rate of complete occlusion was 96.8% in surgical series and 60.4% in EVT (P < 0.001). Recanalization occurred in 9 aneurysms (5.8%) of EVT and 1 aneurysm (3.2%) of surgical series (P = 0.360). In non-dorsal group, transient complications (10 aneurysms (5.4%), P = 0.018) and morbidity at last visiting (6 aneurysms (3.2%), P = 0.021) were more present in surgically treated cases rather than in EVT cases. Diplopia and visual field defect occurred in the non-dorsal group only; in 2 of 11 surgical cases (18.2%) and in 1 of 124 EVT series (0.8%) (P = 0.017). The overall rate of excellent or good clinical outcomes (Glasgow outcome scale 5 or 4) was 98.9%., Conclusion: EVT is a safe and effective treatment for the non-dorsal group. Based on angiographic and clinical aspects, microsurgical clipping has prior efficacy with better outcomes in the dorsal group under proper individualized selection., (Copyright © 2014 Elsevier B.V. All rights reserved.)