Thromboembolic Events With the Woven Endobridge Device: Incidence, Predictive Factors, and Management.

BACKGROUND AND OBJECTIVES: The Woven EndoBridge (WEB) device has been increasingly used to treat wide-neck aneurysms showing a safe and effective profile, but a relatively high number of thromboembolic events (TEEs) have been reported with such treatment. We aimed to evaluate the incidence and management of TEEs and possible predictive factors related to WEB embolization of ruptured and unruptured intracranial aneurysms. METHODS: A single-center database with consecutive aneurysms treated with a WEB device between July 2012 and May 2022 was reviewed for intraoperative and delayed TEEs. Univariate and multivariable analyses were used to determine factors associated with TEEs. RESULTS: A total of 266 independent aneurysms were treated with WEB devices in 245 patients (mean age 55.78 ± 11.64 years, 169 (63.5%) females, 80 (30%) ruptured). The overall rate of TEEs is 13% (35/266), including 8.7% intraoperative. Symptomatic TEEs with clinical sequelae at a 3-month follow-up are reported to be 2.6% (7/266) with no TEE-related mortality. Both the replacement of a WEB device during the procedure (adjusted odds ratio = 2.61, 95% CI 1.24-5.49; P = .01) and ruptured aneurysms (adjusted odds ratio = 2.74, 95% CI 1.31-5.7; P = .007) were independent predictors of TEEs. A case-by-case management of intraprocedural TEE is also presented; tirofiban was successfully used in most cases of this cohort. CONCLUSION: In this study, we demonstrated that ruptured aneurysms and WEB device replacement during the procedure were independent predictive factors for TEEs. As a result, making the correct choice of WEB is crucial for improving treatment outcomes. Moreover, with proper medical management of TEEs, minimal morbidity and no mortality could be achieved, which reinforces the safety of the technique.

The Bicêtre occlusion scale is well suited to assess the efficacy of the Contour embolization device.

BACKGROUND: The Contour Embolization Device (CED) is typically assessed using coiling angiographic outcomes. However, these scales do not address device-specific problematics. We evaluated the usability of the Bicêtre occlusion scale (BOS) with the CED. RESULTS: BOS scores can be analyzed as BOSS 0 = no residual flow, BOSS 1 = residual flow inside the CED but with complete neck-sealing, BOSS 2 = neck-remnant, BOSS 3 = aneurysm-remnant, BOSS 1 + 3 = contrast filling inside the device and aneurysmal sac without complete neck-sealing. CONCLUSION: BOS usage should be encouraged as it provides a more comprehensive assessment of the mechanism of CED occlusion, especially considering the potential prognostic value of the neck sealing assessment.

CLinical EValuation of WEB 17 device in intracranial aneuRysms (CLEVER): procedural, 30-day and 1-year safety results for ruptured and unruptured aneurysms.

BACKGROUND: Intrasaccular flow disruption is an endovascular approach for the treatment of wide-neck aneurysms and, more specifically, wide-neck bifurcation aneurysms, which are challenging to treat with previously developed technologies. The Woven EndoBridge (WEB) device has demonstrated its efficacy and safety, for both unruptured and ruptured aneurysms. METHODS: The CLEVER study was an observational, multicenter, prospective study conducted in 17 European investigational sites using the WEB 17 device, for the treatment of ruptured and unruptured aneurysms. The study objective was to provide safety and efficacy data on the WEB 17 device in the treatment of wide-neck bifurcation aneurysms. Imaging results were assessed independently by a Corelab and adverse events adjudicated by a Clinical Event Adjudicator. This analysis reports procedural results and safety at 30 days and 12 months. RESULTS: A total of 163 patients (mean age 58.1 years; 68.1% women) with 103 unruptured aneurysms and 60 ruptured aneurysms were enrolled. Most aneurysms were located on the anterior communicating artery (ACom) (37.4%) or the middle cerebral artery (MCA) bifurcation (30.1%). Aneurysm widths ranged from 2.0-9.2 mm, and the mean sac width was 5.0 mm. The WEB procedure was successfully completed in 163 patients (100%). At the 12-month follow-up, major stroke events occurred in 3 of 163 patients (1.8%), and no device-related mortality was observed. CONCLUSION: Endovascular treatment of ruptured and unruptured wide-neck bifurcation aneurysms using WEB 17 is safe, with a low complication rate and no device-related mortality. In particular, none of the ruptured aneurysms bled again up to 1 year of follow-up. TRIAL REGISTRATION NUMBER: NCT03844334.

How a decade of aneurysms embolization with the Woven EndoBridge has changed our understanding and practices?

BACKGROUND: Safety and efficacy of the WEB (Woven EndoBridge) device have been extensively evaluated in several good clinical practice studies. Nonetheless, the WEB had several structural evolutions overtime up to the fifth generation WEB device (WEB17). Here, we tried to understand how this may have modified our practices and enlarged our indications for its use. METHODS: We retrospectively analyzed data from all patients with aneurysms treated (or intended to be treated) with a WEB at our institution between July 2012 and February 2022. The time frame was split in two periods: before and after the arrival of the WEB17 in our center (February 2017). RESULTS: 252 patients with 276 wide-necked aneurysms were included; 78 aneurysms (28.2%) were ruptured. Successful embolization with a WEB device was achieved in 263/276 aneurysms (95.3%). With the availability of WEB17, treated aneurysms were significantly smaller (8.2 mm versus 5.9 mm, p<0.001) and off-label location significantly increased (4.4% versus 17.3%, p = 0.02) with an increase of sidewall aneurysm (4.4% versus 11.6%, p = 0.06). Also, WEB were more significantly oversized (1.05 versus 1.11, p<0.01). Adequate and complete occlusion rates increased constantly during the two periods (54.8% versus 67.5%, p = 0.08 and 74.2% versus 83.7%, p = 0.10, respectively). The proportion of ruptured aneurysms slightly increased between the two periods (24.6% versus 29.5%, p = 0.44). CONCLUSIONS: Over the first decade of its availability, the WEB device usage shifted towards smaller aneurysms and broader indications, including ruptured aneurysms. The oversizing strategy also became the standard of practice for WEB deployment in our institution.

The Utility of Multimodal Imaging and Artificial Intelligence Algorithms for Overlying Two Volumes in the Decision Chain for the Treatment of Complex Pathologies in Interventional Neuroradiology-A Case Series Study.

3D rotational angiography is now increasingly used in routine neuroendovascular procedures--in particular, for situations where the analysis of two overlayed sets of volume imaging proves useful for planning the treatment strategy or for confirming the optimal apposition of the intravascular devices used. The aim of this study is to identify and describe the decision algorithm for which the overlay function of 3D rotational angiography volumes, high-resolution contrast-enhanced flat panel detector CT adapted for intravascular devices (VasoCT/DynaCT), non-enhanced flat detector C-arm volume acquisition functionality integrated with the angiography equipment (XperCT/DynaCT), and isovolumetric MRI volumes were all used in treatments performed in a series of 29 patients. Two superposed 3DRA volumes were used in the treatment aneurysms located at the junction of two vascular territories and for arteriovenous malformations with compartments fed from different vascular territories. The superposition function of a preoperatively acquired 3DRA volume and a postoperatively acquired VasoCT volume provides accurate information about the apposition of neuroendovascular endoprostheses used in the treatment of aneurysms. The automatic overlay function generated by the 3D workstation is particularly useful, but in about 50% of cases it requires manual operator-dependent correction, requiring a certain level of experience. In our experience, multimodal imaging brings an important benefit, both in the treatment decision algorithm and in the assessment of neuroendovascular treatment efficacy.

Management of aneurysmal recurrence after Woven EndoBridge (WEB) treatment.

BACKGROUND: Around 10% of Woven EndoBridge device (WEB)-treated intracranial aneurysms will need retreatment, and it is generally believed to be more challenging than retreatment after an initial coiling. We aim to report retreatment strategies and outcomes after initial WEB embolizations. METHODS: Databases from four treatment centers, containing consecutive aneurysms treated with a WEB between 2013 and 2022, were reviewed. Demographics, aneurysm characteristics, retreatment strategies and outcomes were collected and analyzed. RESULTS: From a 756 WEB database, 57 aneurysms were included. The global retreatment rate was 7.5% (95% CI 5.6% to 9.4%). The retreatment rate was significantly higher in the ruptured compared with the unruptured population (13% vs 3.9%, respectively, P<0.0001). Aneurysms were retreated on average 21.2 months after the initial WEB treatment (range 4.8-70 months). Surgery was performed in 11% and endovascular treatment in 89% of cases, consisting of flow diversion (48%), stent-assisted coiling (30%), coiling (12%), and second WEB placement (10%). Imaging follow-up was available in 88% of all WEB retreatments (50/57) (average 17 months, 49% digital subtraction angiography), demonstrating complete occlusion in 56% and 'adequate' occlusion in 88%. Morbidity was 5.3% (95% CI 0% to 12.0%) and mortality 0%. No patient experienced rebleeding during the follow-up period. CONCLUSION: The retreatment rate after an initial WEB treatment seems to compare favorably with that of coiling. Endovascular treatment of recurrence following WEB implantation is feasible in most situations; it generally requires the use of a stent and leads to a high rate of satisfactory occlusion.

CLinical Assessment of WEB device in Ruptured aneurYSms (CLARYS): 12-month angiographic results of a multicenter study.

BACKGROUND: The CLinical Assessment of WEB device in Ruptured aneurYSms (CLARYS) study has shown that the endovascular treatment of ruptured bifurcation aneurysms with the Woven EndoBridge (WEB) is safe and effective and provides protection against rebleeding at 1 month and 1 year. The 12-month angiographic follow-up is an important endpoint of the study. METHODS: The CLARYS study is a prospective multicenter study conducted in 13 European centers. The study enrolled 60 patients with 60 ruptured aneurysms of the anterior and posterior circulation. The study was conducted with an independent assessment of safety outcomes and imaging. RESULTS: Sixty patients with 60 ruptured bifurcation aneurysms to be treated with the WEB were included. Fifty-three aneurysms (88.3%) had a broad base with a dome to neck ratio <2 (mean 1.6). Of these, 46 patients were evaluated by an independent core laboratory with follow-up imaging performed at 12 months or before eventual retreatment. At 1 year, 19/46 aneurysms (41.3%) were completely occluded (Raymond-Roy grade I), 21/46 (45.7%) had a residual neck and 6/46 (13.0%) had residual aneurysm filling. Adequate occlusion was reported in 40/46 (87%) aneurysms. Six patients underwent target aneurysm retreatment. CONCLUSIONS: The CLARYS study has previously shown that the use of the WEB in the endovascular treatment of ruptured bifurcation aneurysms provides effective protection against rebleeding with a good safety profile. The angiographic occlusion rates at 1 year reported here are comparable to those already seen in previous multicenter studies which primarily included unruptured aneurysms.

Antithrombotic therapies for neurointerventional surgery: a 2021 French comprehensive national survey.

BACKGROUND: Neurointerventionists lack guidelines for the use of antithrombotic therapies in their clinical practice; consequently, there is likely to be significant heterogeneity in antithrombotic use between centers. Through a nationwide survey, we aimed to obtain an exhaustive cross-sectional overview of antithrombotic use in neurointerventional procedures in France. METHODS: In April 2021, French neurointerventional surgery centers were invited to participate in a nationwide 51-question survey disseminated through an active trainee-led research collaborative network (the JENI-RC). RESULTS: All 40 centers answered the survey. Fifty-one percent of centers reported using ticagrelor and 43% used clopidogrel as premedication before intracranial stenting. For flow diversion treatment, dual antiplatelet therapy was maintained for 3 or 6 months in 39% and 53% of centers, respectively, and aspirin was prescribed for 12 months or more than 12 months in 63% and 26% of centers, respectively. For unruptured aneurysms, the most common heparin bolus dose was 50 IU/kg (59%), and only 35% of centers monitored heparin activity for dose adjustment. Tirofiban was used in 64% of centers to treat thromboembolic complications. Fifteen percent of these comprehensive stroke centers reported using tenecteplase to treat acute ischemic strokes. Cangrelor appeared as an emergent drug in specific indications. CONCLUSION: This nationwide survey highlights the important heterogeneity in clinical practices across centers. There is a pressing need for trials and guidelines to further evaluate and harmonize antithrombotic regimens in the neurointerventional field.

Determinants of cerebral aneurysm occlusion after embolization with the WEB device: a single-institution series of 215 cases with angiographic follow-up.

BACKGROUND: Woven EndoBridge (WEB) devices are becoming a reliable option for the treatment of wide-neck bifurcation aneurysms, but clear predictive factors are still missing to understand the one in five aneurysm remnant rate. OBJECTIVE: To evaluate occlusion outcomes after WEB treatment to identify potential determinants of aneurysm occlusion. METHODS: A single-center database with consecutive aneurysms treated with WEB between July 2012 and October 2021 was reviewed for potential determinants of aneurysm adequate occlusion (defined as a Bicêtre Occlusion Scale Score (BOSS) of 0, 0', 1 or 2), through univariate and multivariable analysis. Patients without angiographic follow-up were excluded. RESULTS: 215 of 247 individual aneurysms were included in the final analysis, of which 59 (27%) were ruptured. Mean age of patients was 56 years (range 23-90 years) and 65% were female. Mean angiographic follow-up was at 18 months (range 3-97 months). Adequate and complete occlusion were achieved in 171/215 (79.5%) and 135/215 (62.8%) of cases, respectively. Aneurysm irregular shape (aOR=0.42, 95% CI 0.20 to 0.88; p=0.02), aneurysm height (aOR=0.79, 95% CI 0.66 to 0.94; p<0.01), and WEB shape modification (aOR=0.98, 95% CI 0.97 to 1.00; p=0.02) were all independent predictors of aneurysm recurrence, whereas the WEB oversizing ratio (WEB width/aneurysm mean width) (aOR=16.4, 95% CI 1.4 to 266.7; p=0.04) was an independent predictor of adequate occlusion. CONCLUSION: In this study we demonstrated that a width oversizing strategy of the WEB device was an independent predictor of aneurysm angiographic occlusion. Conversely, aneurysm height, irregular aneurysm, and WEB shape modification were all independent determinants of angiographic aneurysm remnant. These results may help to select aneurysms suitable for the WEB device and WEB sizing.

Intracranial Aneurysm in Pediatric Population: A Single-Center Experience.

PURPOSE: Pediatric intracranial aneurysms (PIA) are rarer and more complex when compared to adult aneurysms. In general, the clinical presentation of PIA is due to a mass effect, but the presenting symptoms can be also related to ischemia, subarachnoid hemorrhage (SAH), or in a combination of different symptoms. This paper aimed to report a single-center experience with clinical and angiographic aspects of brain aneurysm in children. METHODS: We retrospectively reviewed our prospectively maintained database for patients with intracranial aneurysms in our institution from July 2015 to February 2021. Among these, all patients under 18 years of age submitted to a diagnostic or therapeutic procedure for an intracranial aneurysm were included. RESULTS: Twelve patients were submitted to diagnostic or therapeutic procedures in our department. Three of them had multiple aneurysms, and in total, 17 intracranial aneurysms were assessed in this study. The most frequent location was in the middle cerebral artery (7 cases/41%). Five out of twelve children (42%) presented SAH due to ruptured aneurysm. Three patients (25%) had symptoms due to the mass effect from large aneurysms, with compression of cranial nerves or brainstem. Aneurysms diameters ranged from 1.5 mm to 34 mm (mean 14.2 mm), with six aneurysms being giant and eight being nonsaccular/fusiform. Twelve aneurysms were submitted to endovascular treatment, with one treatment-related clinical complication and later death. CONCLUSION: PIAs are rare diseases that can arise from a variety of different underlying pathological mechanisms. The management of these conditions requires a detailed understanding of the pathology and a multidisciplinary approach. Despite the availability of new technologies, parent vessel occlusion remains a valid option for aneurysms in the pediatric population.

CLinical Assessment of WEB device in Ruptured aneurYSms (CLARYS): results of 1-month and 1-year assessment of rebleeding protection and clinical safety in a multicenter study.

BACKGROUND: The primary goal of the CLARYS study is to assess the protection against rebleeding when treating ruptured bifurcation aneurysms with the Woven EndoBridge (WEB) device. METHODS: The CLARYS study is a prospective, multicenter study conducted in 13 European centers. Patients with ruptured bifurcation aneurysms were consecutively included between February 2016 and September 2017. The primary endpoint was defined as the rebleeding rate of the target aneurysm treated with the WEB within 30 days postprocedure. Secondary endpoints included periprocedural and postprocedural adverse events, total procedure and fluoroscopy times, and modified Rankin Scale score at 1 month and 1 year. RESULTS: Sixty patients with 60 ruptured bifurcation aneurysms to be treated with the WEB were included. A WEB device was successfully implanted in 93.3%. The rebleeding rate at 1 month and 1 year was 0%. The mean fluoroscopy time was 27.0 min. Twenty-three periprocedural complications were observed in 18 patients and resolved without sequelae in 16 patients. Two of these complications were attributed to the procedure and/or the use of the WEB, leading to a procedure/device-related intraoperative complication rate of 3.3%. Overall mortality at 1 month and 1 year was 1.7% and 3.8%, respectively and overall morbidity at 1 month and 1 year was 15% and 9.6%, respectively. WEB-related 1-month and 1-year morbidity and mortality was 0%. CONCLUSIONS: The interim results of CLARYS show that the endovascular treatment of ruptured bifurcation aneurysms with the WEB is safe and effective and, in particular, provides effective protection against rebleeding. It may induce profound change in the endovascular management of ruptured bifurcation aneurysms.

WEB device for treatment of posterior communicating artery aneurysms.

BACKGROUND: Woven EndoBridge (WEB) device treatment of wide-neck bifurcation aneurysms has proved to be safe and effective, but the use of these devices in sidewall aneurysms has been reported only in a small number of case series. OBJECTIVE: To report our results in a cohort of consecutive patients in whom a WEB device was used as first-line treatment for posterior communicating artery (PComA) aneurysms. METHODS: We conducted a retrospective analysis of a prospectively maintained database of PComA aneurysms treated with a WEB device in our institution from June 1, 2012 to November 15, 2020. Clinical and radiological findings were evaluated at immediate and last follow-up. RESULTS: A total of 219 aneurysms were treated with a WEB device, including 15 PComA aneurysms in 15 patients, 10 of which were ruptured. Aneurysms were wide necked, with a mean aspect ratio of 1.6 (range 0.7-3.0) and a mean neck size of 4.2 mm (range 2.6-7.4 mm). No intraoperative rupture occurred and only one thromboembolic event was noted. Among the group with at least a 3-month digital subtraction angiography (DSA) follow-up, complete and adequate occlusion were obtained in 54% and 72%, respectively (average follow-up 13 months). Re-treatment was needed for two initially ruptured aneurysms. No procedure-related morbidity or mortality was reported. CONCLUSION: This series suggests the high safety profile of WEB devices even when used in off-label indications. Treatment with these devices seems to be a valuable strategy for ruptured wide-neck PComA aneurysms, avoiding the need for antiplatelet medication. However, occlusion rates should be investigated in further larger studies.

Woven EndoBridge device shape modification can be mitigated with an appropriate oversizing strategy: a VasoCT based study.

BACKGROUND: The Woven EndoBridge (WEB) shape modification (WShM) during follow-up may be a potential cause of poor angiographic outcomes. WShM predisposing factors have not yet been determined. Our systematic use of rotational cone beam computed tomography (VasoCT) imaging during follow-up allowed us to perform the first quantitative analysis of the shape of WEBs over time. Our goal was to identify possible strategies to reduce the occurrence of this phenomenon. METHODS: All patients treated in our hospital with a WEB device between October 2015 and January 2019 were included. Using VasoCT acquisitions, systematically performed after implantation and during follow-up, we analyzed WEB morphology. WShM was defined as the percentage reduction in the distance between the two WEB markers. RESULTS: Sixty-three aneurysms treated with a WEB device were finally included in this analysis. At the last follow-up (mean 15.5 months), mean WShM was 48%±24. The mean WShM was significantly higher in the aneurysm recurrence group than in the adequate occlusion group (51±6.5% vs 36±3.4%, difference 15% points (95% CI 0.7 to 30); p<0.05). Conversely, the extent of WShM did not directly correlate with occlusion rates. Indeed, 32% of completely occluded aneurysms presented severe WShM (≥50%). Importantly, the absence of WShM guaranteed complete occlusion in our study (n=12). We demonstrated that oversizing the width of the WEB significantly correlated with WShM reduction during follow-up (r=-0.38, p=0.002). CONCLUSION: WShM can be partly overcome by use of an appropriate width oversizing strategy that could lead to improved angiographic results.

Extending the stroke treatment window beyond DAWN in patients with very slow progressor type collaterals: How far can we go?

Five trials published in 2015 showed the benefit of endovascular thrombectomy (ET) in patients with stroke and large vessel occlusion, extending the treatment window has become an obsession of all physicians. In 2018, the DAWN and DEFUSE-3 trials showed that, with careful selection of patients, the procedure could be carried out up to 24 hours after symptom onset with good outcomes. In addition, there have been cases where the DAWN criteria were met, and treatment occurred >24 hours after symptom onset. We present the case of a 68-year-old female whose groin puncture occurred 52 hours after the time last known well (TLKW), after neurological worsening of the initial situation, with a large mismatch ratio observed on magnetic resonance imaging, achieving TICI (the Thrombolysis in Cerebral Infarction scale) grade 3 recanalization. Five days after the procedure, the patient was discharged with NIHSS (National Institutes of Health Stroke Scale) score of 3. Some types of collateral circulation (slow progressors and "turtle" progressors, our term for very slow progressors) can extend the treatment window beyond 24 hours of the TLKW but can lead to a hyperperfusion-like syndrome immediately after the ET. Further studies are needed to evaluate the reproducibility of this hypothetical syndrome.

Pre-procedural predictive factors of symptomatic intracranial hemorrhage after thrombectomy in stroke.

OBJECTIVE: Symptomatic intracerebral hemorrhage (sICH) is a common complication of acute ischemic stroke (AIS) associated with limited treatments and poor outcomes. We aimed to identify predictive factors of sICH in patients with AIS following mechanical thrombectomy (MT) in a real-world setting. METHODS: Patients with large vessel occlusion of the anterior circulation treated with MT were consecutively included in a prospective monocentric cohort. Clinical, biological, and radiological parameters were collected to identify pre-procedural predictors for sICH. RESULTS: 637 patients were included in our study. Magnetic resonance imaging was performed on most patients (86.7%). sICH occurred in 55 patients (8.6%). 428 patients (67.2%) were treated with intravenous thrombolysis. After multivariate analysis, prior use of antiplatelet therapies (odd ratio (OR) 1.84, 95% confidence interval (CI) 1.01-3.32), high C-reactive protein (OR per standard deviation (SD) increase 1.28, 95% 1.01-1.63), elevated mean arterial blood pressure (OR per 10 mmHg increase 1.22, 95% CI 1.03-1.44), hyperglycemia (OR per one SD-log increase 1.38, 95% CI 1.02-1.87), and low ASPECTS (OR per 1-point decrease 1.42, 95% CI 1.12-1.80) were found to be independent predictive factors of sICH. The pre-procedural predictors did not change when the absence of successful recanalization was considered as a covariate. Patients with strokes of unknown onset time were not especially vulnerable for sICH. CONCLUSION: sICH after MT was associated with several pre-procedural risk factors: prior use of antiplatelet therapies, high C-reactive protein and hyperglycemia at baseline, elevated mean arterial blood pressure, and low ASPECTS.

Spinal arteriovenous malformation without endovascular arterial access: is a combined neurosurgical approach and direct venous puncture an option?

This case report describes a combined neurosurgical and endovascular approach for the treatment of a conus medullaris arteriovenous malformation resulting in considerable improvement in the patient's neurological condition (modified Rankin Scale score 2).

Republished: Spinal arteriovenous malformation without endovascular arterial access: is a combined neurosurgical approach and direct venous puncture an option?

This case report describes a combined neurosurgical and endovascular approach for the treatment of a conus medullaris arteriovenous malformation resulting in considerable improvement in the patient's neurological condition (modified Rankin Scale score 2).

Y-stenting with braided stents for wide-neck intracranial bifurcation aneurysms. A single-center initial experience.

INTRODUCTION: The treatment of wide-neck bifurcation aneurysms is still challenging despite the use of new techniques, such as Y-stenting, the waffle-cone technique and intrasaccular flow disrupters, in recent years. Moreover, the use of flow diverter stents in bifurcation aneurysms has been proposed by several teams, although the results remain controversial. This study aims to evaluate the feasibility and efficacy of Y-stent assisted coiling of bifurcation aneurysms with braided stents. METHODS: We retrospectively reviewed all patients in whom Y-stenting with braided stents had been performed in our center. Six patients were identified and analyzed. Technical success, complications, angiographic outcomes, procedural data, and follow-up controls are reported here. This study was approved by our local ethical committee. RESULTS: Technical success was achieved in all procedures. Overall procedure-related morbidity and mortality was 0%. In the immediate post-treatment angiography, adequate occlusion (neck remnant or total occlusion) was observed in all patients. Short- and long-term follow-up angiography showed adequate occlusion of the aneurysms. CONCLUSIONS: In this small, retrospective single-center analysis we showed that Y-stent assisted coiling with braided stents is a safe and feasible technique. Moreover, it has a high immediate occlusion rate and very good long-term stability.

The PHASES score: To treat or not to treat? Retrospective evaluation of the risk of rupture of intracranial aneurysms in patients with aneurysmal subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: The PHASES score was formulated to predict the 5-year risk of rupture for intracranial aneurysms. We retrospectively analyzed all patients treated in our institution for aneurysmal SAH and applied the PHASES score to estimate the probable predicted risk of bleeding in this group of patients. METHODS: Between February 2015 and August 2018, all patients with aneurysmal SAH were retrospectively analyzed and the PHASES score was applied. A total of 155 patients were included with a mean age of 53.8years, including 60 males and 95 females. RESULTS: Of our patients 110 (70.9%) had a PHASES score of below or equal to 5, with a hemorrhagic risk of up to 1.3% over 5years. If we analyze the patients with a risk of below 2% this figure increases to 122 patients (78.7%). Of these 99.3% were European and 0.6% were Japanese (1 patient). In 86 patients (55.4%), the aneurysm was smaller than 5mm and in 10 patients (6.4%) the aneurysm was located in the posterior circulation. CONCLUSION: Of our patients 78.7% had less than a 2% 5-year rupture risk based on their PHASES score, highlighting the discrepancy of the rupture risk calculated with the PHASES score when hypothetically applied to this group of patients. In the hypothetical scenario that our patients had unruptured aneurysms, our retrospective analysis shows that the PHASES score may only provide a weak tool for clinicians to use in the decision-making process as to whether or not to treat these aneurysms.

Flow diversion treatment of aneurysms of the complex region of the anterior communicating artery: which stent placement strategy should 'I' use? A single center experience.

BACKGROUND: Aneurysms of the anterior communicating artery (ACoA) are difficult to treat with coiling or clipping because of the anatomical variation in this region. Flow diversion represents a feasible treatment, but no consensus exists as to which stent deployment technique is more suitable. METHODS: All patients with ACoA aneurysms treated with flow diverters between April 2014 and November 2018 were retrospectively analyzed. Aneurysm characteristics, follow-up results, and clinical outcome data were recorded, and a new classification comparing the diameters of both A1 segments is proposed: H1=same diameters; H2=<50% difference in diameters; H3= ≥50% difference; and Y=no A1 segment. RESULTS: We analyzed 30 procedures in 30 patients with ACoA aneurysms, including 16 ruptured aneurysms treated with coiling embolization and 4 previously unruptured aneurysms (two Medina and two Woven EndoBridge devices). Adequate aneurysm occlusion occurred in 86.9%; one patient (3.3%) experienced symptomatic ischemic stroke. The global thromboembolic complications for each group were 17.6% (H1), 25% (H2), and 60% (H3). CONCLUSION: Flow diversion treatment in this region is safe, feasible, and effective. The most suitable anatomical configuration for flow diverter treatment seems to be the H1 configuration where the 'I technique' is suitable (from an A1 segment to the ipsilateral A2). There is a tendency that the H3 configuration is not a good indication for flow diverter treatment. However, further studies are needed to evaluate the feasibility of this anatomical classification and the reproducibility of our findings.