Persistent Opacification of the Woven EndoBridge Device: A Conebeam CT Analysis of the Bicêtre Occlusion Scale Score 1 Phenomenon.

BACKGROUND AND PURPOSE: Some Woven EndoBridge devices present a persistent intradevice opacification at imaging follow-up, described as the Bicêtre Occlusion Scale Score 1 (BOSS 1) phenomenon. The clinical implications remain unknown. We aimed here to analyze the factors influencing this occurrence and to precisely describe the evolution of BOSS 1 with time using conebeam CT. MATERIALS AND METHODS: We retrospectively analyzed a prospectively maintained Woven EndoBridge database at our tertiary center and included all patients with isolated BOSS 1 and BOSS 1 associated with small neck remnant (BOSS 1 + 2). RESULTS: Two hundred sixty-seven aneurysms were treated with a Woven EndoBridge device between July 2012 and December 2021. Follow-up with DSA was available for 220 aneurysms (median, 5 months), among which BOSS 1 and 1 + 2 were found in 9.1% (20/220) (95% CI, 5.5%-12.7%). A second DSA follow-up (median, 17 months) was performed in 15 of these 20 aneurysms, which revealed that 40% had evolved to complete Woven EndoBridge occlusion, 33% showed a decreased persistent opacification, and 27% remained stable. BOSS 1 was significantly associated with postoperative antiplatelet medication, a lower aneurysm aspect ratio, and the use of the Woven EndoBridge 17 (P < .05). The average Woven EndoBridge shape modification was less pronounced in the BOSS 1 population (P < .02). None of the BOSS 1 or 1 + 2 aneurysms required retreatment or were associated with hemorrhage occurrence. CONCLUSIONS: Isolated persistent flow inside the Woven EndoBridge device at follow-up is rare and notably associated with antiplatelet prescription. It seems to present a benign course in most cases.

Aneurysm Treatment with Woven EndoBridge-17: Angiographic and Clinical Results at 12 Months from a Retrospective, 2-Center Series.

BACKGROUND AND PURPOSE: This retrospective, 2-center study investigated the feasibility, safety, and efficacy at 12-month follow-up of the treatment of ruptured, unruptured, and recurrent intracranial aneurysms using the latest generation of the Woven EndoBridge (WEB) device, the WEB-17 system. MATERIALS AND METHODS: Aneurysms treated with WEB-17 were extracted from the databases of 2 neurovascular centers. Patients, aneurysm characteristics, complications, and clinical and anatomic results were analyzed. RESULTS: From February 2017 to May 2021, two hundred twelve patients with 233 aneurysms (181/233, 77.7%, unruptured-recurrent, and 52/233, 22.3%, ruptured) were included. High treatment feasibility (95.3%) was reported and was similar in ruptured aneurysms (94.2%) and unruptured-recurrent aneurysms (95.6%) (P = .71) and in typical (95.4%) and atypical (94.7%) locations (P = .70), but it was lower in aneurysms with an angle between the parent artery and main aneurysm axis of ≥45° (90.2%) compared with those with an angle of <45° (97.1%) (P = .03). Global mortality and morbidity were 1.9% and 3.8% at 1 month, respectively, and 4.4% and 1.9% at 12 months, respectively. One-month morbidity (P = .02) and mortality (P = .003) were higher in the ruptured group (10.0% and 8.0%, respectively) compared with unruptured-recurrent group (1.9% and 0.0%, respectively). Overall adequate occlusion (complete occlusion and neck remnant) was 86.3%. The percentage of adequate occlusion was higher (P = .05) in the unruptured-recurrent group (88.5%) compared with the ruptured group (77.5%). CONCLUSIONS: The WEB-17 system showed high feasibility for ruptured and unruptured aneurysms, typical and atypical locations, and some aneurysms with an angle of ≥45°. As the most recent generation device, the WEB-17 also demonstrates high safety and good efficacy.

Impact of A1 Asymmetry on the Woven EndoBridge Device in Anterior Communicating Artery Aneurysms.

BACKGROUND AND PURPOSE: Woven EndoBridge (WEB) devices are increasingly used to treat intracranial aneurysms. A1 asymmetry contributes to anterior communicating artery aneurysm formation and to treatment instability after coiling. We sought to evaluate whether A1 asymmetry had an impact on angiographic outcome in anterior communicating artery aneurysms treated with the WEB. MATERIALS AND METHODS: Anterior communicating artery aneurysms treated between July 2012 and July 2020 with the WEB from an institutional review board-approved database were reviewed. A1 asymmetry was categorized as the following: absence of the A1 segment on 1 side (unilateral A1) versus bilateral A1. Univariate and multivariable analyses assessed independent predictors of adequate (WEB Occlusion Scale A, B, and C) and complete occlusion (WEB Occlusion Scale A and B). RESULTS: Forty-eight individual aneurysms (47 patients) were included in the final analysis, of which 16 (33%) were acutely ruptured. The mean size was 6.5 (SD, 2.2) mm. Adequate and complete occlusion was achieved in 33 (69%) and 30 (63%) cases, respectively. Unilateral A1 was associated with significantly higher rates of adequate (92% versus 60% for bilateral A1; P = .03) and complete occlusion (92% versus 50% for bilateral A1; P < .01). Multivariable logistic regression confirmed unilateral A1 as an independent predictor of both adequate (OR = 10.6; 95% CI, 1.6-220.7; P = .04) and complete occlusion (OR = 9.5, 95% CI, 1.5-190.2; P = .04. A sensitivity analysis comparing unilateral "functional" A1 with bilateral "functional" A1 showed similar results. WEB shape modification was not influenced by the unilateral A1 configuration (P = .70). CONCLUSIONS: Anterior communicating artery aneurysms with a unilateral A1 configuration treated with WEB devices are associated with better angiographic outcome than those with bilateral A1. This finding supports the hypothesis that WEB devices are resistant to unilateral flow in the aneurysm as opposed to coils.

Endovascular Treatment of Small and Very Small Intracranial Aneurysms with the Woven EndoBridge Device.

BACKGROUND AND PURPOSE: The Woven EndoBridge has proved to be a safe and effective treatment, especially for wide-neck intracranial aneurysms. The recent fifth-generation Woven EndoBridge came with smaller devices. The purpose of this study was to assess the safety and efficiency of Woven EndoBridge treatment of small and very small aneurysms. MATERIALS AND METHODS: Between September 2017 and March 2020, all consecutive patients treated with a 3- or 3.5 mm-width Woven EndoBridge device were included in this retrospective intention-to-treat study. Clinical and radiologic findings were evaluated at immediate and last-available follow-up. Angiographic outcome was assessed by an external expert reader. RESULTS: One hundred twenty-eight aneurysms were treated with a fifth-generation Woven EndoBridge device including 29 with a width of ≤3.5 mm. Ten aneurysms were ruptured (34%). In 3 cases (10%), Woven EndoBridge treatment could not be performed because the aneurysm was still too small for the smallest available Woven EndoBridge device and another endovascular strategy was chosen. The median follow-up time was 11.2 months. Complete and adequate occlusion was obtained in 71% and 90% of the treated aneurysms, respectively. Retreatment was needed in 2 cases (10%). Symptomatic ischemic complications leading to transient neurologic deficits occurred in 2 cases (7%) (1 procedure-related and 1 device-related) but with full spontaneous recovery at discharge. CONCLUSIONS: The fifth-generation Woven EndoBridge device seems to be a safe and technically feasible treatment for both ruptured and unruptured small and very small intracranial aneurysms, with satisfactory occlusion rates on midterm follow-up. However, further study is needed to evaluate longer-term efficiency.

"Snowflake" H mode in a tokamak plasma.

An edge-localized mode (ELM) H-mode regime, supported by electron cyclotron heating, has been successfully established in a "snowflake" (second-order null) divertor configuration for the first time in the TCV tokamak. This regime exhibits 2 to 3 times lower ELM frequency and 20%-30% increased normalized ELM energy (ΔWELM/Wp) compared to an identically shaped, conventional single-null diverted H mode. Enhanced stability of mid- to high-toroidal-mode-number ideal modes is consistent with the different snowflake ELM phenomenology. The capability of the snowflake to redistribute the edge power on the additional strike points has been confirmed experimentally.

64Cu enrichment using the Szilard-Chalmers effect - The influence of γ-dose.

Cu is an important trace metal which plays a role in many biological processes. The radioisotope 64Cu is often used to study such processes. Furthermore, 64Cu finds applications in cancer diagnostics as well as therapy. For all of these applications 64Cu having high specific activity is needed. 64Cu can be produced in cyclotrons or in nuclear reactors. In this paper we study the effect of gamma dose on the production of 64Cu according to the Szilard-Chalmers reaction using Cu(II)-phthalocyanine as a target. For this purpose, irradiations were performed in the nuclear reactor of the Delft University of Technology using a novel irradiation facility helping to limit the dose produced by gammas present in the reactor pool. The obtained 64Cu activity yield was in general above 60% in accordance to the theoretical expected value. An increase in gamma dose has no significant influence on the obtained activity yield but increases the loss of Cu from Cu(II)-phthalocyanine up to 0.9% and hence decreases the specific activity that can be obtained. However, without optimisation, when reducing the gamma dose specific activities in the order of 30 TBq/g can be achieved.

The application of atomic layer deposition in the production of sorbents for 99Mo/99mTc generator.

New production routes for 99Mo are steadily gaining importance. However, the obtained specific activity is much lower than currently produced by the fission of U-235. To be able to supply hospitals with 99Mo/99mTc generators with the desired activity, the adsorption capacity of the column material should be increased. In this paper we have investigated whether the gas phase coating technique Atomic Layer Deposition (ALD), which can deposit ultra-thin layers on high surface area materials, can be used to attain materials with high adsorption capacity for 99Mo. For this purpose, ALD was applied on a silica-core sorbent material to coat it with a thin layer of alumina. This sorbent material shows to have a maximum adsorption capacity of 120 mg/g and has a99mTc elution efficiency of 55 ± 2% based on 3 executive elutions.

Nidal embolization of brain arteriovenous malformations using Onyx in 94 patients.

BACKGROUND AND PURPOSE: To report our experience in the treatment of brain arteriovenous malformations (BAVMs) using Onyx (ev3, Irvine, Calif). PATIENTS AND METHODS: From January 1999 to October 2004, 94 patients with BAVMs were treated endovascularly in our department. They were 51 (54%) men and 43 (46%) women with a mean age of 32 years. A total of 210 endovascular procedures were performed with Onyx as the sole embolic agent in 88 procedures; Onyx and n-butyl cyanoacrylate (n-BCA) were used in combination in 50 procedures, and n-BCA alone was used in 72 procedures. RESULTS: The course of endovascular treatment was completed in 53 patients. In 26 patients (49%, 26/53) an angiographic cure was achieved using embolization as the sole therapeutic technique. Seven (13%, 7/53) patients underwent a surgical resection of the residual BAVM nidus, 20 (38%, 20/53) patients underwent radiosurgical treatment after nidal size reduction <2 cm was accomplished by endovascular treatment. Further endovascular treatment was planned in 33 patients, whereas in 5 patients, the continuation of embolization was aborted due to difficult nidus catheterization. Procedure-related permanent neurologic deficits were observed in 8 (8.5%, 8/94) patients. There were 3 procedure-related deaths. CONCLUSION: Onyx is suitable for brain BAVM embolizations and allows obtaining higher rates of anatomic cures compared with those obtained previously with other embolic agents.

[Preoperative mixed embolization of a paraganglioma using Onyx]. / Embolisation préopératoire par abord mixte d'un paragangliome à l'aide d'Onyx.

Paragangliomas, or glomus tumors, are highly vascular benign tumors of the head and neck. Clinical symptoms are essentially progressive and neurological, involving infiltration of the regional cranial nerves. The usual treatment is surgery, which itself is a challenge because of the close proximity of vital structures and the considerable blood loss. Preoperative embolization can reduce morbidity, and several techniques have been described using arterial injection of particles or of cyanoacrylate directly into the tumor. This case report is of a patient treated by surgery using a new technique-preoperative embolization involving both the arteries and veins, and injection of Onyx, resulting in complete devascularization of the tumor's arteriovenous network.

Understanding Angiography-Based Aneurysm Flow Fields through Comparison with Computational Fluid Dynamics.

BACKGROUND AND PURPOSE: Hemodynamics is thought to be an important factor for aneurysm progression and rupture. Our aim was to evaluate whether flow fields reconstructed from dynamic angiography data can be used to realistically represent the main flow structures in intracranial aneurysms. MATERIALS AND METHODS: DSA-based flow reconstructions, obtained during interventional treatment, were compared qualitatively with flow fields obtained from patient-specific computational fluid dynamics models and quantitatively with projections of the computational fluid dynamics fields (by computing a directional similarity of the vector fields) in 15 cerebral aneurysms. RESULTS: The average similarity between the DSA and the projected computational fluid dynamics flow fields was 78% in the parent artery, while it was only 30% in the aneurysm region. Qualitatively, both the DSA and projected computational fluid dynamics flow fields captured the location of the inflow jet, the main vortex structure, the intrasaccular flow split, and the main rotation direction in approximately 60% of the cases. CONCLUSIONS: Several factors affect the reconstruction of 2D flow fields from dynamic angiography sequences. The most important factors are the 3-dimensionality of the intrasaccular flow patterns and inflow jets, the alignment of the main vortex structure with the line of sight, the overlapping of surrounding vessels, and possibly frame rate undersampling. Flow visualization with DSA from >1 projection is required for understanding of the 3D intrasaccular flow patterns. Although these DSA-based flow quantification techniques do not capture swirling or secondary flows in the parent artery, they still provide a good representation of the mean axial flow and the corresponding flow rate.

Large Basilar Apex Aneurysms Treated with Flow-Diverter Stents.

BACKGROUND AND PURPOSE: The treatment of wide-neck, large basilar apex aneurysms is challenging with either an endovascular or a surgical approach. The aim of the present study was to report our experience treating basilar apex aneurysms with flow-diverter stents and to evaluate their efficacy and safety profile in this specific anatomic condition. MATERIALS AND METHODS: We retrospectively analyzed data from all consecutive patients treated with flow-diverter stents at our institution between January 2011 and January 2015. Patients with large basilar apex aneurysms treated with a flow-diverter stent were included in the study. Clinical presentations, technical details, intra- and perioperative complications, and clinical and angiographic outcomes were recorded, with a midterm follow-up. RESULTS: Of the 175 aneurysms treated with flow-diverter stents at our institution, 5 patients (2 women and 3 men; age range, 44-58 years) received flow-diverter stent for basilar apex aneurysms. The mean follow-up after stent deployment was 21 months (range, 15-24 months). One patient died on day 31 from an early postprocedural midbrain hemorrhage. One patient had a right cerebellar hemispheric ischemic lesion with a transient cerebellar syndrome resolved within 24 hours without neurologic sequelae at the latest follow-up. The mRS was 0 in 4 patients and 6 in 1 patient at last follow-up. CONCLUSIONS: Flow diversion is a feasible technique with an efficacy demonstrated at a midterm follow-up, especially in the case of basilar apex aneurysm recurrences after previous endovascular treatments. Concern about its safety profile still exists.

Ellipsoid approximation versus 3D rotational angiography in the volumetric assessment of intracranial aneurysms.

BACKGROUND AND PURPOSE: The purpose of this study was to compare the volumetric results of intracranial aneurysms obtained by calculation of the volume of an ellipsoid with those obtained with 3D rotational angiography (3D-RA). METHODS: First, the precision of 3D-RA in the assessment of volumetric measurement of intracranial aneurysm had to be established. The 3D-RA gave an overestimation of 4% to 5.5% of the actual volume of a spherical object. Then, 484 consecutive human intracranial aneurysms were studied with 3D-RA, allowing the determination of their volume. In the meantime, aneurysm dimensions (height and width) were measured on the 3D pictures generated by the 3D-RA. The aneurysm volumes were obtained by considering the aneurysm shape to be ellipsoidal, according to the formula: (formula in text). RESULTS: The calculated aneurysm volume (V(calc)) overestimated by 15 +/- 38% the volume given by 3D-RA. Taking into account a 10% margin of error, 227 (47%) aneurysms were overestimated by 44 +/- 34%, whereas 113 (23%) aneurysms were underestimated by 25 +/- 12%. Only 144 (30%) aneurysms had calculated and 3D-RA results within the limits of 10% of discrepancy. Concordance was good for pericallosal and basilar tip aneurysms (mean overestimation of 6 +/- 22% and 8 +/- 27%, respectively). Conversely, there was a high discrepancy between calculated and 3D-RA results for posterior communicating artery aneurysms (mean overestimation of 22 +/- 44%). CONCLUSION: The calculation of the volume based on aneurysm dimensions is relatively accurate for pericallosal and basilar tip aneurysms, probably owing to their spherical or elliptic shape. Conversely, this formula is not adequate for irregularly shaped lesions, such as posterior communicating aneurysms.

[Transarterial embolisation of intracranial dural arteriovenous malformations with ethylene vinyl alcohol copolymer (Onyx18)]. / Embolisation par voie artérielle de malformations artérioveineuses durales intracrâniennes à l'aide d'ethylvinyl alcool copolymère (Onyx18).

OBJECTIVE: To report our recent experience in transarterial embolisation of dural arteriovenous malformations (DAVM) using a new liquid embolic agent, Onyx18. PATIENTS AND METHODS: 6 patients were enrolled in this series. Clinical presentation was separated into 2 groups: aggressive (n=2), non aggressive (n=4). The DAVM was located at the superior sagittal sinus (n=1), at the transverse sinus (n=2), at the condylian canal (n=1), in the lesser sphenoid wing region (n=1), and in the tentorium region (n=1). The DAVM drained directly into a condylian or a cortical vein for three patients and into a venous sinus with cortical venous reflux for the three others. In this latter situation, the sinus was anatomically excluded from the normal brain venous drainage. RESULTS: A full brain angiogram including both internal carotid arteries, both external carotid arteries and ipsilateral vertebral artery, was performed before and after each treatment. The feeder chosen after a selective catheterisation for Onyx18 injection was always meningeal. Each treatment consisted of a single Onyx injection after one unique feeder catheterisation. Complete anatomical exclusion of the DAVM was achieved and demonstrated by the post treatment angiogram in all cases. There was no clinical complication after the treatment. CONCLUSION: Onyx18 used is a safe treatment for DAVMs. When its injection is performed in optimal conditions, it fills the total DAVM and its drainage vein or sinus after a single arterial feeder catheterisation.

COBB syndrome treated by staged intravascular embolisation and surgery.

A 28-year old Malay man with evidence of an upper motor neuron cord lesion was diagnosed to have a C7 to T2 spinal arterio-venous malformation and associated cutaneous vascular lesion. He finally agreed for treatment after 5 years of progressive spastic right lower limb weakness leading to inability to mobilize. A two staged intravascular procedure was done followed by surgery with recovery of ASIA impairment scale grade B.

Flow-Diverter Stents for the Treatment of Saccular Middle Cerebral Artery Bifurcation Aneurysms.

BACKGROUND AND PURPOSE: The flow-diverter stent has been proved a feasible, safe, and efficient technique, particularly for the treatment of large and broad-neck carotid siphon aneurysms. Wide-neck bifurcation aneurysms remain, in some cases, a challenge for neurointerventionalists. We report the outcomes of the treatment of saccular middle cerebral artery bifurcation aneurysms with flow diversion in our institution. MATERIALS AND METHODS: From the institution data base, all saccular, nondissecting MCA bifurcation aneurysms, treated with flow-diverter stents, were retrospectively reviewed. Technical issues, immediate posttreatment and follow-up angiographic findings, and clinical outcomes were assessed. RESULTS: Fourteen patients with 15 aneurysms were included in the study. Ischemic complications, as confirmed by MR imaging, occurred in 6 patients (43%). Procedure-related morbidity and mortality at last follow-up were 21% and 0%, respectively. Angiographic follow-up was available for 13 aneurysms, with a mean follow-up of 16 months. Complete occlusion was obtained for 8 aneurysms (62%). CONCLUSIONS: Compared with other available therapeutic options, the flow-diverter stent does not appear to be a suitable solution for the treatment of saccular MCA bifurcation aneurysms.

Does Arterial Flow Rate Affect the Assessment of Flow-Diverter Stent Performance?

BACKGROUND AND PURPOSE: Our aim was to assess the performance of flow-diverter stents. The pre- and end-of-treatment angiographies are commonly compared. However, the arterial flow rate may change between acquisitions; therefore, a better understanding of its influence on the local intra-aneurysmal hemodynamics before and after flow-diverter stent use is required. MATERIALS AND METHODS: Twenty-five image-based aneurysm models extracted from 3D rotational angiograms were conditioned for computational fluid dynamics simulations. Pulsatile simulations were performed at different arterial flow rates, covering a wide possible range of physiologic flows among 1-5 mL/s. The effect of flow-diverter stents on intra-aneurysmal hemodynamics was numerically simulated with a porous medium model. Spatiotemporal-averaged intra-aneurysmal flow velocity and flow rate were calculated for each case to quantify the hemodynamics after treatment. The short-term flow-diverter stent performance was characterized by the relative velocity reduction inside the aneurysm. RESULTS: Spatiotemporal-averaged intra-aneurysmal flow velocity before and after flow-diverter stent use is linearly proportional to the mean arterial flow rate (minimum R2 > 0.983 of the linear regression models for untreated and stented models). Relative velocity reduction asymptotically decreases with increasing mean arterial flow rate. When the most probable range of arterial flow rate was considered (3-5 mL/s), instead of the wide possible flow range, the mean SD of relative velocity reduction was reduced from 3.6% to 0.48%. CONCLUSIONS: Both intra-aneurysmal aneurysm velocity and flow-diverter stent performance depend on the arterial flow rate. The performance could be considered independent of the arterial flow rates within the most probable range of physiologic flows.

WEB Treatment of Intracranial Aneurysms: Clinical and Anatomic Results in the French Observatory.

BACKGROUND AND PURPOSE: Flow disruption with the WEB device is a new technique for the endovascular treatment of wide-neck bifurcation aneurysms. To obtain precise data regarding the safety and efficacy of this treatment with high-quality methodology, the prospective French Observatory study was conducted. Analysis of these data is presented, including 1-year follow-up. MATERIALS AND METHODS: Patients with bifurcation aneurysms for which WEB treatment was indicated were included in this prospective, multicenter Good Clinical Practice study. Clinical data, including adverse events and clinical status at 1 month and 1 year, were collected and independently analyzed by a medical monitor. An independent core laboratory evaluated the anatomic results at 1 year following the procedure. RESULTS: Ten French neurointerventional centers included 62 patients (39 women), 33-74 years of age (mean, 56.6 ± 9.80 years) with 63 aneurysms. Aneurysm locations were the middle cerebral artery in 32 aneurysms (50.8%), anterior communicating artery in 16 (25.4%), basilar artery in 9 (14.3%), and internal carotid artery terminus in 6 (9.5%). Morbidity and mortality at 1 month were, respectively, 3.2% (2/62 patients) and 0.0% (0/62). Morbidity and mortality (unrelated to the treatment) at 1 year were, respectively, 0.0% (0/59) and 3.4% (2/59 patients). At 1 year, complete occlusion was observed in 30/58 aneurysms (51.7%); neck remnant, in 16/58 aneurysms (27.6%); and aneurysm remnant, in 12/58 aneurysms (20.7%). CONCLUSIONS: This prospective French Observatory study showed very good safety of aneurysm treatment with the WEB, with a high rate of adequate aneurysm occlusion at 1 year (79.3%).

[Endovascular treatment of unruptured middle cerebral artery aneurysms]. / Traitement endovasculaire des anévrysmes non rompus de l'artère cérébrale moyenne.

INTRODUCTION: Middle cerebral artery aneurysms (MCA) often present an unusual anatomical feature for the endovascular treatment and are frequently sent to surgery. We report our experience in the endovascular treatment of unruptured MCA aneurysms and compare it with results from the neurosurgical literature. PATIENTS AND METHODS: In this retrospective study were included all patients with unruptured MCA aneurysms treated in our institution between November 1998 and December 2003. 3D imaging was performed in all cases to determine precisely the relationship between aneurysm and parent artery. The degree of occlusion of the aneurysms was estimated according to Raymond's classification. The neurological state was evaluated according to the Rankin scale and was re-evaluated at the time of each follow-up. RESULTS: Eighty four patients with 100 aneurysms were analysed. Ninety aneurysms were treated by endovascular approach. Nine aneurysms were sent to surgery, after 3D imaging analyses or failed endovascular treatment. In one patient, related to the aneurysm configuration, a conservative attitude has been adopted. Four giant aneurysms were treated by parent vessel occlusion and 86 aneurysms were selectively occluded. The remodelling technique with balloon was performed in 58.1% of cases. Eight patients presented a new neurological deficit. The deficit was transient in six cases, and permanent in 2 cases. There was no mortality in this series. In 86 aneurysms selectively treated, there were 87.2% good results (grades A and B). Seventy one aneurysms (82.5%) treated were controlled between 3 and 58 months with a 19.6 months average. Recurrences were observed in 25.3% of cases. They were major in 9.8% and retreatment was performed. CONCLUSION: We report the feasibility of the endovascular treatment of MCA aneurysms previously estimated untreatable. Per procedural 3D imaging and remodelling technique were fundamental tools in the management of these aneurysms.

WEB Treatment of Intracranial Aneurysms: Feasibility, Complications, and 1-Month Safety Results with the WEB DL and WEB SL/SLS in the French Observatory.

BACKGROUND AND PURPOSE: Safety analyses in the French Observatory have shown that treatment of intracranial aneurysms by using flow disruption with the Woven EndoBridge Device (WEB) is safe, with low morbidity and no mortality. The objective of this study was to analyze treatment feasibility, complications, and safety results in patients treated with the Woven EndoBridge Device Dual-Layer (WEB DL) and Woven EndoBridge Device Single-Layer/Single-Layer Sphere (WEB SL/SLS) in the French Observatory. MATERIALS AND METHODS: Patients with bifurcation aneurysms were included in this prospective, multicenter good clinical practices study. A medical monitor independently analyzed procedural and clinical data. The study started with the WEB DL, and secondarily, the WEB SL/SLS was authorized in the study. RESULTS: Between November 2012 and January 2014, 10 French centers included 62 patients with 63 aneurysms. Thirty patients with 31 aneurysms were treated with the WEB DL, and 32 patients with 32 aneurysms, with the WEB SL/SLS. The percentage of anterior communicating artery aneurysms treated with WEB SL/SLS was significantly higher (37.5%) compared with WEB DL (12.9%) (P = .04). The WEB SL/SLS was more frequently used in aneurysms of <10 mm than the WEB DL (respectively, 96.9% and 67.7%; P = .002). Morbidity was similar in both groups (WEB DL, 3.3%; WEB SL/SLS, 3.1%), and mortality was 0.0% in both groups. CONCLUSIONS: This comparative study shows increased use of WEB treatment in ruptured, small, and anterior communicating artery aneurysms when using WEB SL/SLS. There was a trend toward fewer thromboembolic complications with the WEB SL/SLS. With both the WEB DL and WEB SL/SLS, the treatment was safe, with low morbidity and no mortality.

Single-Layer WEBs: Intrasaccular Flow Disrupters for Aneurysm Treatment­Feasibility Results from a European Study.

BACKGROUND AND PURPOSE: The safety and efficiency of the dual-layer Woven EndoBridge (WEB) device has already been published. However, this international multicenter study sought to evaluate the safety of single-layer devices, which are the newest generation of the WEB intrasaccular flow-disrupter family. They have been designed to offer smaller-sized devices with a lower profile to optimize navigability and delivery, which may, in turn, broaden their range of use. MATERIALS AND METHODS: Data from all consecutive patients treated with a single-layer WEB device, in 10 European centers from June 2013 to May 2014 were included. Clinical presentations, technical details, intra- and perioperative complications, and outcomes at discharge were recorded. Clinical and angiographic data at last follow-up were also analyzed when available. RESULTS: Ninety patients with 98 WEB-treated aneurysms were included in this study. In 93 cases (95%), WEB placement was possible. Complete occlusion at the end of the procedure was obtained in 26 instances (26%). Additional treatment during the procedure (coiling and/or stent placement) was necessary in 12 cases (12.7%). Procedure-related complications occurred in 13 cases, leading to permanent neurologic deficits in 4 patients (4.4%). Early vascular imaging follow-up data were available for 44 patients (57%), with an average time interval of 3.3 months. Treatment-related morbidity and mortality rates at last follow-up were 2.2% and 1.1%, respectively. CONCLUSIONS: In this study, the feasibility and safety of the single-layer WEB device was comparable with that of the double-layer. However, further studies are needed to evaluate long-term efficacies.