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.

Flow Diversion for ICA Aneurysms with Compressive Neuro-Ophthalmologic Symptoms: Predictors of Morbidity, Mortality, and Incomplete Aneurysm Occlusion.

BACKGROUND AND PURPOSE: Flow diversion is an effective treatment for aneurysms of the ICA with compression-related neuro-ophthalmologic symptoms, especially when treatment is initiated early after symptom onset and aneurysm occlusion is complete. However, non-negligible complication rates have been reported. Our aim was to identify risk factors for morbidity/mortality and incomplete aneurysm occlusion. MATERIALS AND METHODS: We performed a secondary analysis of a previous publication, which included all patients treated with flow diversion for an unruptured aneurysm of the ICA with compression-related symptoms. RESULTS: Fifty-four patients with 54 aneurysms (48 women, 88.9%; mean age, 59.2 [SD, 15.9] years; range, 21-86 years) treated with flow diversion were included. We observed morbidity and mortality rates of 7.4% and 3.7%. Increasing age (OR per decade, 3.2; 95% CI, 1.23-8.49; P = .02) and dual-antiplatelet therapy with ticagrelor (OR, 13.9; 95% CI, 1.16-165.97; P = .04) were significantly associated with morbidity/mortality. After a median follow-up of 13.3 [SD, 10.5] months, the rates of complete aneurysm occlusion, neck remnant, and aneurysm remnant were 74%, 14%, and 12%. Incomplete occlusion at follow-up was less frequently observed in aneurysms treated with additional coil embolization (OR, 0.1; 95% CI, 0.01-0.86; P = .04). CONCLUSIONS: Although a promising treatment for compressive ICA aneurysms, flow diversion carries a relevant risk for complications and incomplete aneurysm occlusion. Our results may help identify patients in which flow diversion may not be the ideal treatment method. Additional coil embolization increased the likelihood of complete aneurysm occlusion at follow-up.

Fast Stent Retrieval during Mechanical Thrombectomy Improves Recanalization in Patients with the Negative Susceptibility Vessel Sign.

BACKGROUND AND PURPOSE: In acute ischemic stroke, the negative susceptibility vessel sign on T2*-weighted images traditionally highlights fibrin-rich clots, which are particularly challenging to remove. In vitro, fast stent retrieval improves fibrin-rich clot extraction. We aimed to evaluate whether the speed of stent retrieval influences the recanalization and clinical outcome of patients presenting with the negative susceptibility vessel sign. MATERIALS AND METHODS: Patients were identified from a registry of patients with ischemic stroke receiving mechanical thrombectomy between January 2016 and January 2020. Inclusion criteria were the following: 1) acute ischemic stroke caused by an isolated occlusion of the anterior circulation involving the MCA (Internal Carotid Artery-L, M1, M2) within 8 hours of symptom onset; 2) a negative susceptibility vessel sign on prethrombectomy T2*-weighted images; and 3) treatment with a combined technique (stent retriever + contact aspiration). Patients were dichotomized according to retrieval speed (fast versus slow). The primary outcome was the first-pass recanalization rate. RESULTS: Of 68 patients who met inclusion criteria, 31 (45.6%) were treated with fast retrieval. Patients receiving a fast retrieval had greater odds of first-pass complete (relative risk and 95% confidence interval [RR 95% CI], 4.30 [1.80-10.24]), near-complete (RR 95% CI, 3.24 [1.57-6.68]), and successful (RR 95% CI, 2.60 [1.53-4.43]) recanalization as well as greater odds of final complete (RR 95% CI, 4.18 [1.93-9.04]), near-complete (RR 95% CI, 2.75 [1.55-4.85]), and successful (RR 95% CI, 1.52 [1.14-2.03]) recanalization. No significant statistical differences in procedure-related serious adverse events, distal embolization, or symptomatic intracranial hemorrhage were reported. No differences were noted in terms of functional independence (RR 95% CI, 1.01 [0.53-1.93]) and all-cause mortality (RR 95% CI, 0.90 [0.35-2.30]) at 90 days. CONCLUSIONS: A fast stent retrieval during mechanical thrombectomy is safe and improves the retrieval of clots with the negative susceptibility vessel sign.

Persistent Blood Flow inside the Woven EndoBridge Device More Than 6 Months after Intracranial Aneurysm Treatment: Frequency, Mechanisms, and Management-A Retrospective Single-Center Study.

BACKGROUND AND PURPOSE: Due to its high safety and great efficacy, flow disruption with the Woven EndoBridge (WEB) device is increasingly used to treat intracranial aneurysms. We recently identified patients with intracranial aneurysm treated with the WEB who presented with residual blood flow inside the device ("contrast-in-WEB" phenomenon) more than 6 months posttreatment. This series reports the frequency and underlying mechanisms and discusses management of this phenomenon. MATERIALS AND METHODS: All patients presenting with the contrast-in-WEB phenomenon in the prospectively collected data base of patients with aneurysm treated with the WEB were retrospectively collected and analyzed. RESULTS: From June 2011 to February 2019, one hundred twenty-seven patients with 133 aneurysms were treated with the WEB and had DSA follow-up at 6 months or later. Eight patients (6.3%) presented with the phenomenon. All aneurysms were wide-neck bifurcation aneurysms, including 7 unruptured and 1 ruptured aneurysm located at the MCA (5 aneurysms), anterior communicating artery (2 aneurysms), and basilar artery (1 aneurysm). All except 1 patient received dual-antiplatelet therapy preprocedure. All except 1 patient received dual-antiplatelet therapy postoperatively for at least 1 month. The most likely mechanism of the phenomenon is the absence of intradevice thrombosis related to perioperative dual-antiplatelet medication. The phenomenon is also likely associated with a low risk of bleeding except when there is residual blood flow against the aneurysm wall or in the dome. CONCLUSIONS: Contrast-in-WEB is a relatively rare phenomenon possibly induced by dual-antiplatelet therapy continued post-WEB procedure. In most cases, no additional treatment is required.

Fast Stent Retrieval Improves Recanalization Rates of Thrombectomy: Experimental Study on Different Thrombi.

BACKGROUND AND PURPOSE: About 20% of patients with acute ischemic stroke due to large-artery occlusion do not achieve recanalization with mechanical thrombectomy. We aimed to determine whether the speed of retrieval of the stent retriever influences the efficacy in removing different clot types. MATERIALS AND METHODS: Sixty mechanical thrombectomies were performed using an in vitro pulsatile cerebrovascular circulation model with controlled pressure and flow rate. Experiments were dichotomized into fast and slow retrieval using a wedging technique, in which the stent retriever and distal catheter are retrieved together. We used 3 different clot types: erythrocyte-rich, fibrin-rich, and friable clots. Primary end points were complete (TICI 3) and successful (TICI 2b-3) recanalizations. Secondary measures were distal and new territory embolizations. RESULTS: Fast retrieval was more frequently associated with complete (RR = 1.83; 95% CI, 1.12-2.99) and successful recanalization (RR = 1.50; 95% CI, 1.03-2.19) than slow retrieval, without a difference in distal embolization (RR = 0.75; 95% CI, 0.29-1.90). There were no emboli in a new territory. The advantage of fast retrieval over slow retrieval differed according to the clot composition, with a stronger effect with fibrin-rich clots with regard to complete (RR = 4.00; 95% CI, 1.11-14.35; Pint = .04) and successful (Pint = .10) recanalization. CONCLUSIONS: In our experimental model, a fast removal improved recanalization rates of mechanical thrombectomy, especially in the case of fibrin-rich clots. An in vivo confirmation is warranted to see whether our findings can have an impact in clinical practice.

Aneurysm Characteristics, Study Population, and Endovascular Techniques for the Treatment of Intracranial Aneurysms in a Large, Prospective, Multicenter Cohort: Results of the Analysis of Recanalization after Endovascular Treatment of Intracranial Aneurysm Study.

BACKGROUND AND PURPOSE: The Analysis of Recanalization after Endovascular Treatment of Intracranial Aneurysm (ARETA) prospective study aims to determine factors predicting recurrence after endovascular treatment for intracranial aneurysms. In this publication, we review endovascular techniques and present the study population. Characteristics of treated and untreated unruptured aneurysms were analyzed. MATERIALS AND METHODS: Sixteen neurointerventional departments prospectively enrolled patients treated for ruptured and unruptured intracranial aneurysms between December 2013 and May 2015. Patient demographics, aneurysm characteristics, and endovascular techniques were recorded. RESULTS: A total of 1289 patients with 1761 intracranial aneurysms, 835 (47.4%) ruptured, were enrolled. Of these, 1359 intracranial aneurysms were treated by endovascular means. Ruptured intracranial aneurysms were treated by coiling and balloon-assisted coiling in 97.8% of cases. In unruptured intracranial aneurysms, the rates of flow diversion, flow disruption, and stent-assisted coiling were 11.6%, 6.9%, and 7.8%, respectively. Rupture status and aneurysm location, neck diameter, and sac size significantly influenced the chosen technique. Treated unruptured intracranial aneurysms, compared with untreated counterparts, had larger aneurysm sacs (7.6 ± 4.0 versus 3.4 ± 2.0 mm; P < 0.001) and neck dimensions (4.1 ± 2.2 versus 2.4 ± 1.3 mm; P < 0.001) and more frequently an irregular form (84.6% versus 44.4%; P < 0.001). Also, its location influenced whether an unruptured intracranial aneurysm was treated. CONCLUSIONS: Our study provides an overview of current neurointerventional practice in the ARETA cohort. The technique choice was influenced by aneurysm morphology, location, and rupture status. Flow diversion, flow disruption, and stent-assisted coiling were commonly used in unruptured intracranial aneurysms, while most ruptured intracranial aneurysms were treated with coiling and balloon-assisted coiling.

Is there a benefit of mechanical thrombectomy in patients with large stroke (DWI-ASPECTS ≤ 5)?

BACKGROUND AND PURPOSE: Whether to withhold mechanical thrombectomy when the diffusion-weighted imaging (DWI) lesion exceeds a given volume is undetermined. Our aim was to identify markers that will help to select patients with large DWI lesions [DWI-Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS) ≤ 5] that may benefit from thrombectomy. METHODS: From May 2010 to November 2016, 82 acute ischaemic stroke patients with DWI-ASPECTS ≤5 (43 men, 64.6 ± 14.4 years, National Institutes of Health Stroke Scale 18.4 ± 5.4) treated with state-of-the-art mechanical thrombectomy were studied. Thrombectomy alone was performed in 28 (34%) and bridging therapy in 54 (66%) patients. Recanalization was defined as a thrombolysis in cerebral infarction score 2B-3 and significant hemorrhagic transformation as parenchymal haematoma type 2 (European Cooperative Acute Stroke Study 3 classification). Pretreatment variables were compared between patients with a good (modified Rankin Scale 0-2) and a poor (modified Rankin Scale 3-6) neurological outcome at 3 months. RESULTS: Overall, 28 patients (34%) achieved good neurological outcome at 3 months. Recanalizers were significantly more likely to achieve good outcome (61% vs. 7.3%, P < 0.0001), had lower mortality (24% vs. 49%, P = 0.03) and similar rates of parenchymal haematoma type 2 (9.8% vs. 7.3%, P = 1) compared to non-recanalizers. Regression modelling identified DWI-ASPECTS >2 [odds ratio (OR) 6.93; 95% confidence interval (CI) 1.05-45.76, P = 0.04), glycaemia ≤6.8 mmol/l (OR 4.05; 95% CI 1.09-15.0, P = 0.03) and thrombolysis (OR 3.67; 95% CI 1.04-12.9, P = 0.04) as independent predictors of good neurological outcome. CONCLUSIONS: In patients with DWI-ASPECTS ≤5, two-thirds of patients experienced good neurological outcome when recanalized by state-of-the-art thrombectomy, whilst only one in 14 non-recanalizers achieved similar outcomes. Pretreatment markers of good neurological outcomes were DWI-ASPECTS >2, intravenous thrombolysis and glycaemia ≤6.8 mmol/l.

Techniques for endovascular treatment of acute ischemic stroke.

Early recanalization of occluded vessels in patients with acute ischemic stroke (AIS) by either intravenous thrombolysis (IVT) or endovascular revascularization has been shown to be associated with improved clinical outcomes and reduced mortality. Since the initial report regarding endovascular treatment (EVT) of AIS in 1983, endovascular techniques have been tremendously improved, advancing from intra-arterial administration of thrombolytic drugs to stent retrievers. IVT has been evaluated in several large randomized trials and has been shown to improve clinical outcomes at 90 days if treatment was initiated within 3h of stroke onset, while its benefit at 3-4.5h was subsequently demonstrated in the European Cooperative Acute Stroke Study (ECASS) III. Thus, EVT had to be evaluated against IVT. The first randomized controlled trials (RCTs) were published in 2013, and demonstrated no major differences between IVT and EVT for AIS, although these trials had important limitations. The positive results of the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke (MR CLEAN) in the Netherlands, followed by five other positive RCTs, finally established the efficacy of mechanical thrombectomy (MT) with stent retrievers (also called 'stentrievers') in AIS due to large vessel occlusion within 6h of stroke onset. Currently, the European and US guidelines recommend MT with stent retrievers as a first-line treatment in the management of AIS. The recent publication of the DWI or CTP Assessment with Clinical Mismatch in the Triage of Wake-Up and Late-Presenting Strokes Undergoing Neurointervention (DAWN) trial is expected to lead to extension of the time window for patients carefully selected by imaging. Thus, optimizing the selection of patients as well as the EVT procedures and techniques used is still an important goal to be evaluated in further trials.

Safety and Efficacy of Aneurysm Treatment with the WEB: Results of the WEBCAST 2 Study.

BACKGROUND AND PURPOSE: Flow disruption with the Woven EndoBridge (WEB) device is an innovative technique for the endovascular treatment of wide-neck bifurcation aneurysms. The initial version of the device (WEB Double-Layer) was evaluated in the WEB Clinical Assessment of IntraSaccular Aneurysm Therapy (WEBCAST) study, whereas the French Observatory study evaluated both WEB Double-Layer and Single-Layer versions of the device. WEBCAST 2 was designed to evaluate the WEB Single-Layer with Enhanced Visualization. MATERIALS AND METHODS: Patients with wide-neck bifurcation aneurysms for which WEB treatment was possible were included. Clinical data including adverse events and clinical status at 1 month and 1 year were collected and analyzed. A core laboratory evaluated anatomic results at 1 year following the procedure. RESULTS: Ten European neurointerventional centers included 55 patients (38 women; 27-77 years of age; mean, 54.4 ± 10.0 years) with 55 aneurysms. Aneurysm locations were the middle cerebral artery in 25 aneurysms (45.5%), the anterior communicating artery in 16 (29.1%), the basilar artery in 9 (16.4%), and the internal carotid artery terminus in 5 (9.1%). Procedural morbidity and mortality at 1 month were, respectively, 1.8% (1/55 patients) and 0.0% (0/55 patients). Morbidity and mortality at 1 year were, respectively, 3.9% (2/51 patients) and 2.0% (1/51 patients). At 1 year, complete occlusion was observed in 27/50 aneurysms (54.0%); neck remnant, in 13/50 (26.0%); and aneurysm remnant, in 10/50 (20.0%) (adequate occlusion in 40/50, 80.0%). CONCLUSIONS: WEBCAST 2 confirms the high safety and efficacy of WEB aneurysm treatment demonstrated in the WEBCAST and French Observatory studies.

Should indications for WEB aneurysm treatment be enlarged? Report of a series of 20 patients with aneurysms in "atypical" locations for WEB treatment.

BACKGROUND AND PURPOSE: Flow disruption with the WEB device is an innovative technique for the endovascular treatment of wide neck bifurcation aneurysms. Good clinical practice trials have shown high safety of this treatment with good efficacy. Technical developments (single layer devices and smaller microcatheters) facilitate the treatment, potentially leading to enlargement of indications. This series is collecting aneurysms in "atypical" locations for WEB treatment and analyzing safety and efficacy of this treatment. MATERIALS AND METHODS: In each participating center, patients with aneurysms treated with WEB were prospectively included in a local database. Patients treated for aneurysms in "atypical" locations were extracted. Patient and aneurysm characteristics, intraoperative complications, and anatomical results at the end of the procedure and at last follow-up were collected and analyzed. RESULTS: Five French neurointerventional centers included 20 patients with 20 aneurysms in "atypical" locations for WEB treatment treated with WEB. Aneurysm locations were ICA carotid-ophthalmic in 9 aneurysms (45.0%), ICA posterior communicating in 4 (20.0%), Pericallosal artery in 5 (25.0%), and basilar artery between P1 and superior cerebellar artery in 2 (10.0%). There were no complications (thromboembolic or intraoperative rupture) in this series. At follow-up (mean: 7.4 months), adequate occlusion was obtained in 100.0% of aneurysms. CONCLUSIONS: This series confirms that it is possible to enlarge indications of WEB treatment to "atypical" locations with good safety and efficacy. These data have to be confirmed in large prospective series.

Are Anatomic Results Influenced by WEB Shape Modification? Analysis in a Prospective, Single-Center Series of 39 Patients with Aneurysms Treated with the WEB.

BACKGROUND AND PURPOSE: Endovascular treatment with the flow-disrupter Woven EndoBridge aneurysm embolization system (WEB) is an innovative treatment for wide-neck bifurcation aneurysms. Prospective, multicenter studies have shown the high safety of this technique. Stability of aneurysm occlusion in long-term follow-up has been rarely studied. Moreover the "compression" phenomenon has been reported and seems to be associated with poor anatomic results. This prospective, single-center series analyzes the safety and efficacy of the WEB device in long-term follow-up in relation to WEB shape modification. MATERIALS AND METHODS: All patients with aneurysms treated with the WEB were prospectively included in a data base. Demographics, aneurysm characteristics, adverse events, and anatomic results were retrospectively analyzed. Anatomic results and modification of the WEB shape on the follow-up examinations were independently evaluated by a core laboratory. RESULTS: Thirty-nine patients were included. We observed few complications: intraoperative rupture in no patients (0.0%) and thromboembolic events in 3 patients (7.7%) with a permanent deficit in 1 (2.6%). At short-term, midterm, and long-term follow-up, adequate occlusion was obtained in 86.8%, 83.3%, and 87.5%, respectively. Retreatment rates were low (5.1%). At 6 months, WEB shape modification (compression/retraction) was observed in 31.6% of patients but was not associated with a lower rate of adequate occlusion. CONCLUSIONS: This prospective, single-center series with WEB devices used in 39 patients during 3.5 years confirms data from previous multicenter studies. Treatment can be accomplished with good safety and efficacy, with a high rate of adequate occlusion. Anatomic results were not worse in case of WEB shape modification.

Efficacy and Safety of the Woven EndoBridge (WEB) Device for the Treatment of Intracranial Aneurysms: A Systematic Review and Meta-Analysis.

BACKGROUND AND PURPOSE: Intrasaccular flow diverters are increasingly being used in the treatment of wide-neck and bifurcation aneurysms. We performed a systematic review and meta-analysis of existing literature on the Woven EndoBridge device in the treatment of intracranial aneurysms. MATERIALS AND METHODS: A comprehensive literature search was performed through October 1, 2015. We extracted information on baseline aneurysm and patient characteristics. Outcomes studied included immediate and midterm (>3 month) angiographic outcomes (complete occlusion as well as adequate occlusion, defined as complete occlusion or neck remnant), aneurysm retreatment, intraoperative rupture, perioperative morbidity and mortality, thromboembolic complications, and treatment failure. Meta-analysis was performed by using the random-effects model. RESULTS: Fifteen uncontrolled series were included in this analysis, including 565 patients with 588 aneurysms, of which 127 were ruptured. Initial complete and adequate occlusion rates were 27% (95% CI, 15%-39%) and 59% (95% CI, 39%-78%), respectively. Midterm complete and adequate occlusion rates after a median of 7 months were 39% (95% CI, 26%-52%) and 85% (95% CI, 78%-91%), respectively. Perioperative morbidity and mortality rates were 4% (95% CI, 1%-8%) and 1% (95% CI, 0%-2%), respectively. Midterm adequate occlusion rates for ruptured aneurysms were 85% (95% CI, 67%-98%), compared with 84% (95% CI, 72%-94%) for unruptured aneurysms (P = .89). Patients with ruptured aneurysm had similar rates of perioperative morbidity to patients with unruptured aneurysm (2%; 95% CI, 0%-26% versus 2%; 95% CI, 0%-6%, respectively; P = .35). CONCLUSIONS: Early evidence derived from uncontrolled studies suggests that Woven EndoBridge treatment has a good safety profile and promising rates of adequate occlusion, especially given the complexity of aneurysms treated. Further prospective clinical trials are needed to confirm these results and better define the risks and benefits of use of the Woven EndoBridge device in treating wide-neck and wide-neck bifurcation aneurysms.

Contrast-Enhanced and Time-of-Flight MRA at 3T Compared with DSA for the Follow-Up of Intracranial Aneurysms Treated with the WEB Device.

BACKGROUND AND PURPOSE: Imaging follow-up at 3T of intracranial aneurysms treated with the WEB Device has not been evaluated yet. Our aim was to assess the diagnostic accuracy of 3D-time-of-flight MRA and contrast-enhanced MRA at 3T against DSA, as the criterion standard, for the follow-up of aneurysms treated with the Woven EndoBridge (WEB) system. MATERIALS AND METHODS: From June 2011 to December 2014, patients treated with the WEB in our institution, then followed for ≥6 months after treatment by MRA at 3T (3D-TOF-MRA and contrast-enhanced MRA) and DSA within 48 hours were included. Aneurysm occlusion was assessed with a simplified 2-grade scale (adequate occlusion [total occlusion + neck remnant] versus aneurysm remnant). Interobserver and intermodality agreement was evaluated by calculating the linear weighted κ. MRA test characteristics and predictive values were calculated from a 2 × 2 contingency table, by using DSA data as the standard of reference. RESULTS: Twenty-six patients with 26 WEB-treated aneurysms were included. The interobserver reproducibility was good with DSA (κ = 0.71) and contrast-enhanced-MRA (κ = 0.65) compared with moderate with 3D-TOF-MRA (κ = 0.47). Intermodality agreement with DSA was fair with both contrast-enhanced MRA (κ = 0.36) and 3D-TOF-MRA (κ = 0.36) for the evaluation of total occlusion. For aneurysm remnant detection, the prevalence was low (15%), on the basis of DSA, and both MRA techniques showed low sensitivity (25%), high specificity (100%), very good positive predictive value (100%), and very good negative predictive value (88%). CONCLUSIONS: Despite acceptable interobserver reproducibility and predictive values, the low sensitivity of contrast-enhanced MRA and 3D-TOF-MRA for aneurysm remnant detection suggests that MRA is a useful screening procedure for WEB-treated aneurysms, but similar to stents and flow diverters, DSA remains the criterion standard for follow-up.