Treatment Of Bifurcation Aneurysms Research Articles

Endovascular Treatment of Bifurcation Aneurysms with the Woven EndoBridge: Product Features and Selected Results of Off-Label Use.

Treatment for wide-neck bifurcation cerebral aneurysms (WNBAs) is widely performed by endovascular treatment as well as open surgical clipping. However, due to factors such as the shape and size of the aneurysms, as well as the anatomical features of surrounding branch vessels, there are some cases in which simple coiling or conventional adjunctive techniques, such as balloon-assisted or neck bridge stent-assisted coiling, are not sufficient to achieve a satisfactory cure. Against this backdrop, the device known as the Woven EndoBridge (WEB) (MicroVention, Aliso Viejo, CA, USA) was developed and can be deployed directly into the aneurysm for treatment. Over a decade has passed since its development, and it is now used in many countries worldwide. This review provides insights into the evolution of the WEB device from its development to the date of this writing, highlighting the unique features of the device and its treatment indications. Additionally, it discusses the posttreatment course, perspectives on recurrence and retreatment, imaging assessments, and potential off-label use based on numerous studies primarily conducted in Europe and the USA.

Flow diversion for the treatment of intracranial bifurcation aneurysms: a systematic review and meta-analysis

BackgroundFlow diversion (FD: flow diversion, flow diverter) is an endovascular treatment for many intracranial aneurysm types; however, limited reports have explored the use of FDs in bifurcation aneurysm management. We...

In vitro flow diversion effect of the ReSolv stent with the shelf technique in a bifurcation aneurysm model

BackgroundFlow-diverting stents are not currently indicated for the treatment of bifurcation aneurysms, and some case series have demonstrated low occlusion rates, possibly due to a lack in neck coverage. The...

Woven EndoBridge versus stent-assisted coil embolization of cerebral bifurcation aneurysms.

Stent-assisted coil (SAC) embolization has been the mainstay endovascular treatment for bifurcation aneurysms. The recent introduction of the Woven EndoBridge (WEB) device has presented an alternative endovascular treatment modality for these aneurysms. Direct comparisons of outcomes between these two modalities are limited in the literature. Here, the authors compared the outcomes of bifurcation aneurysms treated with SAC and WEB devices. This retrospective single-center study comprised 148 bifurcation aneurysms that were treated endovascularly with SAC or WEB devices between 2011 and 2019. The primary outcome was complete occlusion of the aneurysm at 6 months on catheter angiography. The SAC and WEB cohorts comprised 85 and 63 aneurysms, respectively. The baseline characteristics were well balanced after inverse probability weight (IPW) adjustment, except for smoking status. The 6-month complete occlusion rate was higher in the WEB cohort than the SAC cohort (67.4% vs 40.6%; unadjusted OR [95% CI] 3.014 [1.385-6.563], p = 0.005). However, this difference in complete occlusion rates did not remain significant after IPW adjustment and multiple imputations. The neck remnant rate was lower in the WEB cohort than the SAC cohort (20% vs 50%; OR [95% CI] 0.250 [0.107-0.584], p = 0.001), and this difference remained significant after IPW adjustment (OR [95% CI] 0.304 [0.116-0.795], p = 0.015) and multiple imputations. Use of SAC and WEB demonstrated comparable 6-month complete occlusion rates for bifurcation aneurysms. WEB appeared to be associated with a lower rate of neck remnant at 6 and 12 months compared with SAC. WEB was also associated with fewer complications and decreased retreatment rates compared with SAC.

Comparing treatment outcomes of various intracranial bifurcation aneurysms locations using the Woven EndoBridge (WEB) device

BackgroundThe Woven EndoBridge (WEB) device has Food and Drug Administration approval for treatment of wide-necked intracranial bifurcation aneurysms. The WEB device has been shown to result in adequate occlusion in...

Multicenter Study for the Treatment of Sidewall versus Bifurcation Intracranial Aneurysms with Use of Woven EndoBridge (WEB)

Background The Woven EndoBridge (WEB) device was explicitly designed for wide-neck intracranial bifurcation aneurysms. Small-scale reports have evaluated the off-label use of WEB devices for the treatment of sidewall aneurysms, with promising outcomes. Purpose To compare the angiographic and clinical outcomes of the WEB device for the treatment of sidewall aneurysms compared with the treatment of bifurcation aneurysms. Materials and Methods A retrospective review of the WorldWideWEB Consortium, a synthesis of retrospective databases spanning from January 2011 to June 2021 at 22 academic institutions in North America, South America, and Europe, was performed to identify patients with intracranial aneurysms treated with the WEB device. Characteristics and outcomes were compared between bifurcation and sidewall aneurysms. Propensity score matching (PSM) was used to match by age, pretreatment ordinal modified Rankin Scale score, ruptured aneurysms, location of aneurysm, multiple aneurysms, prior treatment, neck, height, dome width, daughter sac, and incorporated branch. Results A total of 683 intracranial aneurysms were treated using the WEB device in 671 patients (median age, 61 years [IQR, 53-68 years]; male-to-female ratio, 1:2.5). Of those, 572 were bifurcation aneurysms and 111 were sidewall aneurysms. PSM was performed, resulting in 91 bifurcation and sidewall aneurysms pairs. No significant difference was observed in occlusion status at last follow-up, deployment success, or complication rates between the two groups. Conclusion No significantly different outcomes were observed following the off-label use of the Woven EndoBridge, or WEB, device for treatment of sidewall aneurysms compared with bifurcation aneurysms. The correct characterization of the sidewall aneurysm location, neck angle, and size is crucial for successful treatment and lower retreatment rate. © RSNA, 2022 See also the editorial by Hetts in this issue.

The Safety and Effectiveness of the Contour Neurovascular System (Contour) for the Treatment of Bifurcation Aneurysms: The CERUS Study.

The Contour is a novel intra-aneurysmal flow disrupting device to treat intracranial aneurysms. To evaluate the safety and effectiveness of the Contour device for treatment of nonruptured intracranial bifurcation aneurysms through a prospective, multicenter, single-arm study. Thirty-four patients were enrolled. Primary end points were successful occlusion at 6 mo for efficacy and any major stroke or nonaccidental death up to 30 d or major disabling stroke within 6 mo for safety. Secondary end points were occlusion at 12 mo, retreatment rate, procedure time, and procedure-related/device-related adverse events. Procedural and follow-up imaging was reviewed by an independent core laboratory. Adverse events were reviewed and adjudicated by a clinical events committee. In total, 32 of 34 aneurysms were successfully implanted and, 2 of 34 in the intention-to-treat (ITT) group did not receive the Contour and were excluded from follow-up after 30 d. In addition, 2 of 32 were lost to angiographic follow-up and regarded as treatment failure. The primary safety end point was met in 2 patients in the ITT group. In the perprotocol (PP) group, complete occlusion was seen in 14 of 32 (44%) at 6 mo and 22 of 32 (69%) at 12 mo. Adequate occlusion (Raymond-Roy [RR] 1 and 2) was reached in 84% at a last available follow-up. One patient from the ITT group and 1 from the PP group received additional treatment during follow-up. The Contour seems to be both safe and effective in the treatment of intracranial bifurcation aneurysms.

Intra-saccular device modeling for treatment planning of intracranial aneurysms: from morphology to hemodynamics.

Intra-saccular devices (ID), developed for the treatment of bifurcation aneurysms, offer new alternatives for treating complex terminal and bifurcation aneurysms. In this work, a complete workflow going from medical images to post-treatment CFD analysis is described and used in the assessment of a concrete clinical problem. Two different intra-saccular device sizes were virtually implanted in 3D models of the patient vasculature using the ID-Fit method. After deployment, the local porosity at the closed end of the device in contact with the blood flow was computed. This porosity was then used to produce a CFD porous medium model of the device. Velocities and wall shear stress were assessed for each model. Six patients treated with intra-saccular devices were included in this work. For each case, 2 different device sizes were virtually implanted and 3 CFD simulations were performed: after deployment simulation with each size and before deployment simulation (untreated). A visible reduction in velocities was observed after device implantation. Velocity and WSS reduction was statistically significant (K-S statistics, [Formula: see text]). Placement of different device size can lead to a partial filling of the aneurysm, either at the dome or at the neck, depending on the particular positioning by the interventionist. The methodology used in this work can have a strong clinical impact, since it provides additional information in the process of device selection using preoperative data.

Endoluminal flow diverters in the treatment of sidewall and bifurcation aneurysm: A systematic review and meta-analysis of complications and angiographic outcomes.

The use of endoluminal flow diversion in bifurcation aneurysms has been questioned due to the potential for complications and lower occlusion rates. In this study we assessed outcomes of endovascular treatment of intracranial sidewall and bifurcation aneurysms with flow diverters. In July 2020, a literature search for all studies utilizing endoluminal flow diverter treatment for sidewall or bifurcation aneurysms was performed. Data were collected from studies that met our inclusion/exclusion criteria by two independent reviewers and confirmed by a third reviewer. Using random-effects meta-analysis the target outcomes including overall complications (hematoma, ischemic events, minor ischemic stroke, aneurysm rupture, side vessel occlusion, stenosis, thrombosis, transient ischemic stroke, and other complications), perioperative complications, and follow-up (long-term) aneurysm occlusion were intestigated. Overall, we included 35 studies with 1084 patients with 1208 aneurysms. Of these aneurysms, 654 (54.14%) and 554 (45.86%) were classified as sidewall and bifurcation aneurysm, respectively, based on aneurysm location. Sidewall aneurysms had a similar total complication rate (R) of 27.12% (95% CI, 16.56%-41.09%), compared with bifurcation aneurysms (R, 20.40%, 95% CI, 13.24%-30.08%) (p = 0.3527). Follow-up angiographic outcome showed comparable complete occlusion rates for sidewall aneurysms (R 69.49%; 95%CI, 62.41%-75.75%) and bifurcation aneurysms (R 73.99%; 95% CI, 65.05%-81.31%; p = 0.4328). This meta-analysis of sidewall and bifurcation aneurysms treated with endoluminal flow diverters demonstrated no significant differences in complications or occlusion rates. These data provide new information that can be used as a benchmark for comparison with emerging devices for the treatment of bifurcation aneurysms.

Particle Image Velocimetry Measurements of the Flow-Diverting Effects of a New Generation of the eCLIPs Implant for the Treatment of Intracranial Bifurcation Aneurysms

Flow diverters (FDs) for the endovascular treatment of intracranial aneurysms are effective for sidewall aneurysms, but their use at a bifurcation is problematic because FDs only partially cover the aneurysm neck and impede flow into a daughter branch; they are thus not employed routinely in this anatomy. eCLIPs was developed as a non-tubular implant to completely cover the neck of an aneurysm and serve as a coil retention device necessary for the adequate treatment of wide-neck bifurcation aneurysms. eCLIPs has shown some flow diversion effects in bifurcation anatomy but not equal to those exhibited by clinically accepted flow diverters in sidewall anatomy. A new generation of eCLIPs implant, the eCLIPs bifurcation flow diverter (eBFD), with higher metal coverage, was developed to achieve a similar flow diversion as a Pipeline Embolization Device (PED), a prototypical FD. Particle image velocimetry was used to capture the fluid dynamics and velocity reduction within silicone aneurysm replicas. A circulatory mimicking loop was developed to circulate the flow through the silicone models. All generations of eCLIPs implants had some flow-diverting effect, with increasing metal coverage density of the implant proportionately increasing the flow diversion effect. The eBFD, with a metal density of 35%, showed greater flow diversion than PED, with 30% metal density, for bifurcation anatomy. The eBFD showed similar reduction of flow in a bifurcation anatomy to PED in a sidewall, both sufficient to permit early thrombosis of the aneurysm. Thus, the eBFD can potentially provide sufficient flow diversion for the treatment of bifurcation aneurysms to avoid adjunctive coiling.

Single-Center Experience With the Bare p48MW Low-Profile Flow Diverter and Its Hydrophilically Covered Version for Treatment of Bifurcation Aneurysms in Distal Segments of the Anterior and Posterior Circulation.

Background and Purpose: Flow diversion has profoundly changed the way aneurysms are treated. However, it conventionally requires dual antiplatelet medication and has yet been considered off-label use in the posterior circulation or within peripheral vessels of the anterior circulation. Here, we report our experience with the p48MW/p48MW hydrophilic coating (HPC) in the anterior and posterior circulation. This novel low-profile flow diverter is specifically designed for treatment of small peripheral vessels, and the p48MW HPC has an anti-thrombotic polymer coating, which allows application of a single antiplatelet function medication in conditions that expectably require further surgery.Materials and Methods: Thirty-two patients were prospectively included. Twenty-six treatments were performed with one flow diverter, four required two overlapping flow diverters, one case demanded three overlapping flow diverters, and in one case, extensive dissecting aneurysm telescoping with eight flow diverters was necessary. Twenty-two complex bifurcation aneurysms were treated. Three months' follow-up was available for 14 patients.Results: Deployment was uneventful in all cases. In four cases, undersizing was unavoidable and resulted in significant shortening of the flow diverter, which demanded implantation of further flow diverters to sufficiently treat the target aneurysm. Three flow diverters required balloon angioplasty for optimal wall approximation. All parent vessels remained patent. Available 3-month follow-up studies showed decreased influx or delayed washout in all aneurysms; none was occluded completely. There were no device-related clinical complications.Conclusions: Implantation of the p48MW/p48MW HPC is safe and effective for treatment of distally located cerebral aneurysms. Considering the reported rates of ischemic complications associated with flow diversion of complex bifurcation aneurysms, the p48MW/p48MW HPC potentially provides increased safety for complex bifurcation aneurysms in the anterior and posterior circulation.

Bifurcation Aneurysm Treatment with PulseRider: Technical Nuances, Device Selection, Positioning Strategies, and Overcoming Geometric Challenges

Endovascular therapy is a viable alternative to surgical clipping for the treatment of intracranial aneurysms; however, aneurysms arising at bifurcations remain a challenge. The purpose of this technical report is to share the nuances of treating aneurysms with the PulseRider (PR), including device selection and positioning strategy, from authors who are highly experienced in its use. We offer a comprehensive guide for neuroendovascular surgeons less experienced with PR applications to include design, general coil embolization technique, principles of deployment and detachment, positioning options, and geometric challenges and their solutions. In our experience, the PR is well suited for addressing the challenges of treating bifurcation aneurysms. PR use is intuitive and straightforward for use in bifurcation aneurysms with ideal favorable. PR can also be safely and effectively used to address a much broader and more challenging range of geometries.

Endovascular treatment of intracranial aneurysms using the Woven EndoBridge (WEB) device: retrospective analysis of a single center experience

IntroductionWoven EndoBridge (WEB) is an innovative device for the treatment of intracranial aneurysms especially wide-necked bifurcation aneurysms. Here we present our experience with the WEB device. Material and methodsPatients treated using only the WEB device between September 2014 and November 2018 were included in the study. Follow up imaging studies and medical records of the patients were retrospectively reviewed. ResultsForty-two aneurysm of 42 patients (27 female, 15 male; median age: 56, range: 32–76) were treated using the WEB device. The mean diameter of the aneurysms was 6.6 mm (range: 3–12 mm). The neck diameter was ≥4 mm in 57% of the aneurysms. The locations of the aneurysms were the middle cerebral artery bifurcation in 29 (69%), basilar tip in 5 (12%), anterior communicating artery in 5 (12%), internal carotid artery tip in 2 (5%), and M1 segment of the middle cerebral artery in 1 (2%) of the patients. Five patients had subarachnoid hemorrhage due to aneurysm rupture. The device could be successfully deployed in all of the cases. There were control imaging studies available for 36 patients who were followed up for a median of 7 months (range: 1–33 months). Adequate occlusion was observed in 35 of these 36 patients (97%). There was no treatment related morbidity or mortality. ConclusionAlthough long term follow-up data are not available, WEB intrasaccular flow disruptor seems to be effective and safe for intracranial bifurcation aneurysm treatment in the mid-term follow up.

The Use of Single Stent-Assisted Coiling in Treatment of Bifurcation Aneurysms: A Multicenter Cohort Study With Proposal of a Scoring System to Predict Complete Occlusion

The development of stent-assisted coiling has allowed for the endovascular treatment of wide-necked bifurcation aneurysms. A variety of options exist, and little is known about the optimal stent configuration in this setting. We report a large multicenter experience of stent-assisted coiling of bifurcations aneurysms using a single stent, with attention to factors predisposing to aneurysm recanalization. To assess the safety and efficacy of single stent-assisted coiling, in addition to analyzing the factors associated with recanalization, and proposal of a predictive scoring scale. A multicenter retrospective analysis of bifurcation aneurysms treated with a single stent-assisted coiling technique between 2007 and 2015 was performed. Clinical and radiographic data were collected and used to develop a scoring system to predict aneurysm occlusion. A total of 74 bifurcation aneurysms were treated with single stent-assisted coiling. At a median follow-up of 15.2 mo, complete occlusion or remnant neck was achieved in 90.6% of aneurysms. Aneurysm location, maximal diameter, neck size, and alpha angle were predictive of aneurysm occlusion at last follow-up. A scoring system to predict complete occlusion based on these factors was developed. An increasing score correlated with a higher rate of complete occlusion. The treatment of bifurcation aneurysm using single stent technique for stent-assisted coiling is safe and effective. Complete occlusion or remnant neck occlusion was achieved in 90.6% of cases. Class III aneurysms can be effectively treated using a single stent, while class I may require Y-stent technique.

Outcomes of Endovascular Treatment of Intracranial Aneurysms at Bifurcation Sites

Background and Purpose: Endovascular coiling is widely used for treatment of both ruptured and unruptured aneurysms. Intracranial bifurcation aneurysms were classically considered unsuitable for endovascular treatment because of the risk of coil protrusion into the parent vessel. The introduction stent assisted coiling has allowed the bifurcation aneurysms to be endovascularly treated. The present study aims to evaluate the efficacy of the endovascular treatment of the intracranial bifurcation aneurysms. Methods: This study was conducted on 76 patients with radiologically documented intracranial aneurysms at bifurcation sites either ruptured (12 aneurysms) or unruptured (64 aneurysms). Endovascular coiling of intracranial aneurysms was done for all patients in our study aided in some with single or Y-configuration stenting. The radiological outcome was assessed immediately postoperative, and at follow-up at 6 and 12 month with grading of the angiograms on the basis of modified 3-point Raymond scale. Results: In terms of the Raymond grading (RG), the initial angiographic outcome was complete occlusion (RG1) in 45 aneurysms (59.2%), neck remnant (RG2) in 20 aneurysms (26.3%), and body filling (RG3) in 11 aneurysms (14.5%), while the final angiographic outcome at 1 year was RG1 in 55 aneurysms (72.4%), RG2 in 13 aneurysms (17.1%), and RG3 in 8 aneurysms (10.5%). Eleven aneurysms (14.5%) showed recanalization. The aneurysm size and the neck width were the statistically significant factors affecting the initial RG (P = 0.0005, 0.001 respectively), final RG (P = 0.015, 0.012 respectively), and the recanalization rate (P = 0.012, 0.01 respectively). Conclusions: Endovascular treatment of intracranial aneurysms at bifurcation sites is safe and effective. Stent assisted coiling (SAC) has enabled us to offer a safe and effective endovascular treatment for bifurcation aneurysms by preventing coils herniation. Smaller aneurysm size and neck size are indicators of complete occlusion and lower recanalization rate.

Letter: Results of the ANSWER Trial Using the PulseRider for the Treatment of Broad-Necked, Bifurcation Aneurysms.

Background The safety and probable benefit of the PulseRider (Pulsar Vascular, Los Gatos, California) for the treatment of broad-necked, bifurcation aneurysms was studied in the context of the prospective, nonrandomized, single arm clinical trial-the Adjunctive Neurovascular Support of Wide-neck aneurysm Embolization and Reconstruction (ANSWER) Trial. Objective To present the results of the United States cases employing the PulseRider device as part of the ANSWER clinical trial. Methods Aneurysms treated with the PulseRider device among sites enrolling in the ANSWER trial were prospectively studied and the results are summarized. Aneurysms arising at either the carotid terminus or basilar apex that were relatively broad necked were considered candidates for inclusion into the ANSWER study. Results Thirty-four patients were enrolled (29 female and 5 male) with a mean age of 60.9 years (27 basilar apex and 7 carotid terminus). Mean aneurysm height ranged from 2.4 to 15.9 mm with a mean neck size of 5.2 mm (range 2.3-11.6 mm). In all patients, the device was delivered and deployed. Immediate Raymond I or II occlusion was achieved in 82.4% and progressed to 87.9% at 6-month follow-up. A modified Rankin Score of 2 or less was seen in 94% of patients at 6 months. Conclusion The results from the ANSWER trial demonstrate that the PulseRider device is safe and offers probable benefit as for the treatment of bifurcation aneurysms arising at the basilar apex or carotid terminus. As such, it represents a useful addition to the armamentarium of the neuroendovascular specialist.

Abstract 201: Results of the ANSWER Trial Using the PulseRider for the Treatment of Broad-necked, Bifurcation Aneurysms

Background: The safety and probable benefit of the PulseRider ® (Pulsar Vascular, San Jose, CA) for the treatment of broad-necked, bifurcation aneurysms was studied in the context of the prospective, non-randomized, single arm clinical trial - the Adjunctive Neurovascular Support of Wide-neck aneurysm Embolization and Reconstruction Trial (ANSWER). Objective: We present the results of the United States cases employing the PulseRider ® device as part of the ANSWER clinical trial. Methods: Aneurysms treated with the PulseRider ® device among U.S. sites enrolling in the ANSWER trial were prospectively studied and the results are summarized. Aneurysms arising at either the carotid terminus or basilar apex that were relatively broad necked were considered candidates for inclusion into the ANSWER study. Results: 34 patients were enrolled (29 female and 5 male) with a mean age of 60.9 years (27 basilar apex and 7 carotid terminus). Mean aneurysm height ranged from 2.4 to 15.9 mm with a mean neck size of 5.2 mm (range 2.3 - 11.6 mm). In all patients the device was delivered and deployed. Immediate Raymond I or II occlusion was achieved in 82.4% and progressed to 87.9% at six month follow up. A modified Rankin Score of 2 or less was seen in 94% of patients at 6 months. Conclusions: The results from the U.S. cases of the ANSWER trial demonstrate that the Pulse Rider® device is safe and effective as for the treatment of bifurcation aneurysms arising at the basilar apex or carotid terminus. As such, it represents a useful addition to the armamentarium of the neuroendovascular specialist.

PulseRider-assisted treatment of wide-necked intracranial bifurcation aneurysms: safety and feasibility study.

OBJECTIVE The goal of this study was to assess the safety and feasibility of PulseRider, a novel endovascular stent, in the treatment of intracranial bifurcation aneurysms with wide necks. The authors present the initial results of the first 10 cases in which the PulseRider device was used. METHODS Patients whose aneurysms were intended to be treated with the PulseRider device at 2 institutions in the United Kingdom were identified prospectively. Patient demographics, procedural details, immediate neurological and clinical status, and immediate angiographic outcomes and 6-month clinical and imaging follow-up were recorded prospectively. RESULTS At the end of the procedure, all 10 patients showed complete aneurysm occlusion (Raymond Class 1). There were no significant intraprocedural complications except for an occurrence of thromboembolism without clinical sequelae. There was no occurrence of aneurysm rupture or vessel dissection. At 6-month follow-up, 7 and 3 patients had modified Rankin Scale scores of 0 and 1, respectively. All 10 patients had stable aneurysm occlusion (Raymond Class 1) and daughter vessel intraluminal patency on 6-month follow-up catheter angiography. CONCLUSIONS The authors' early experience with the PulseRider device demonstrates that it is a safe and effective adjunct in the treatment of bifurcation aneurysms with wide necks arising at the middle cerebral artery bifurcation, anterior cerebral artery, basilar apex, and carotid terminus. It works by providing a scaffold at the neck of the bifurcation aneurysm, enabling neck remodeling and coil support while maintaining parent vessel intraluminal patency. Early clinical and radiological follow-up showed good functional outcome and stable occlusion rates, respectively. Further data are needed to assess medium- and long-term outcomes with PulseRider.

Abstract WMP29: Safety and Efficacy of WEB Flow Disruption in Treatment of Bifurcation Aneurysms: Results in a Cumulated Population of 3 Good Clinical Practice Studies (WEBCAST, French Observatory, WEBCAST 2)

Introduction: Flow Disruption with WEB is an innovative endovascular approach for wide-neck bifurcation aneurysms. Initial series have shown a low complication rate with good efficacy. Hypothesis: To confirm the safety and efficacy of the WEB aneurysm treatment in the cumulated population of WEBCAST (WEB Clinical Assessment of Intrasaccular Aneurysm), French Observatory, and WEBCAST 2 series. Methods: WEBCAST, WEBCAST 2, and French Observatory are single-arm, prospective, multicenter, GCP (Good Clinical Practice) studies dedicated to the evaluation of WEB treatment, conducted in Europe and France. Inclusion criteria were ruptured and unruptured aneurysms in both studies, located in basilar artery, middle cerebral artery, anterior communicating artery, and internal carotid artery terminus. Clinical data were independently evaluated. Post-operative, 6-months (in WEBCAST and WEBCAST 2), and 1-year aneurysm occlusion was independently evaluated using the 3-grade scale: complete occlusion, neck remnant, and aneurysm remnant. Evolution of aneurysm occlusion was evaluated using a simple 3-grade scale: stable, improved, worsened. Results: The cumulated population was 168 patients (112 females, 66.7%) with 169 aneurysms. WEB implant success was 96.4%. Mortality at discharge was 0.6% and morbidity 1.8%. At one-year (mean 12.6 months), complete aneurysm occlusion was observed in 56.0%, neck remnant in 26.0%, and aneurysm remnant in 18.0% (WEBCAST and French Observatory). Conclusions: The analysis in this large cumulated population of studies (WEBCAST, French Observatory, WEBCAST 2) confirms great safety and efficacy of WEB treatment.

Towards Predicting Patient-Specific Flow-Diverter Treatment Outcomes for Bifurcation Aneurysms: From Implantation Rehearsal to Virtual Angiograms.

Despite accounting for the majority of all cerebral aneurysm cases, bifurcation aneurysms present many challenges to standard endovascular treatment techniques. This study examines the treatment of bifurcation aneurysms endovascularly with flow-diverting stents and presents an integrative computational modeling suite allowing for rehearsing all aspects of the treatment. Six bifurcation aneurysms are virtually treated with 70% porosity flow-diverters. Substantial reduction (>50%) in aneurysm inflow due to device deployment is predicted in addition to reductions in peak and average aneurysm wall shear stress to values considered physiologically normal. The subsequent impact of flow-diverter deployment on daughter vessels that are jailed by the device is investigated further, with a number of simulations conducted with increased outlet pressure conditions at jailed vessels. Increased outlet pressures at jailed daughter vessels are found to have little effect on device-induced aneurysm inflow reduction, but large variation (13–86%) is seen in the resulting reduction in daughter vessel flow rate. Finally, we propose a potentially powerful approach for validation of such models, by introducing an angiographic contrast model, with contrast transport modeled both before and after virtual treatment. Virtual angiograms and contrast residence curves are created, which offer unique clinical relevance and the potential for future in vivo verification of simulated results.