Laurent Pierot

Introduction: The Woven EndoBridge (WEB) Embolization System is the first intrasaccular device developed for the treatment of wide-necked bifurcation aneurysms (WNBAs). Here we report the 1-year outcomes for the unruptured aneurysm cohort of the WISE Study (WEB Implant Safety and long-term Effectiveness) database, a pooled analysis of subject-level data from seven prospective WEB trials. Methods: Individual subject-level data from seven prospective, multicenter, core laboratory adjudicated, externally monitored studies evaluating the WEB device for the treatment of unruptured WNBAs were pooled. The included aneurysms had a mean dome width of 6.5 mm. All studies shared the same core laboratory, and five of the seven shared the same clinical events committee. Subject demographic and aneurysm characteristics, procedural data, and effectiveness and safety outcomes were combined and evaluated as a single population. Adequate occlusion was defined as complete occlusion or residual neck on core laboratory assessment. Results: A total of 449 unruptured aneurysms were successfully treated within WISE. The 1-year rates of complete occlusion and adequate occlusion were 54.7% (223/408) and 82.8% (338/408), respectively. Aneurysm recurrence was 6.4% (19/298) and the retreatment rate was 2.5% (11/449). All-cause morbidity was 1.2% (5/416) and treatment-related morbidity (device- and/or procedure-related) was 0.5% (2/416) at 12 months. No ruptures were observed after WEB treatment through 1 year. Complete occlusion was less likely for anterior circulation aneurysms, larger aneurysm height and width, and wider neck. Complete occlusion was less likely for anterior circulation aneurysms and for aneurysms with larger height, width, and neck size (all p<0.05). Greater WEB lateral compression was associated with higher rates of complete occlusion (OR 1.289 for absolute difference and OR 7.042 for ratio, p≤0.0066), and with higher rates of adequate occlusion (OR 1.288 and 8.846, respectively). Retreatment was associated with larger aneurysm height and width, and smoking history. Conclusion: The WEB device is safe and effective for the treatment of unruptured intracranial aneurysms with high rates of adequate occlusion, low rates of recurrence and retreatment, and reliable protection from rupture.

Introduction: The WISE (WEB Implant Safety and long term Efficacy: A pooled analysis of seven clinical trials) study combines data from seven fully adjudicated clinical trials totaling 601 enrolled patients, of which 143 were ruptured aneurysms. This analysis evaluates the safety and effectiveness of the Woven EndoBridge (WEB) device for the treatment of wide neck bifurcation aneurysms in the ruptured aneurysm cohort. Methods: WISE is a pooled analysis that combined patient level data from seven prospective multicenter WEB studies, each conducted with independent core laboratory review of imaging and independent adjudication of adverse events. Patients treated for ruptured aneurysms were identified, and baseline characteristics, procedural details, and 12 month clinical and angiographic outcomes were evaluated. Safety events, including thromboembolic and hemorrhagic complications, vasospasm, and hydrocephalus were assessed. Results: Among 143 patients with ruptured aneurysms, technical success was achieved in 97.2% of cases. Adequate occlusion was achieved in 87.5% of patients with available imaging, including 60.0% with complete occlusion. Retreatment up to 12 months occurred in 6.5% of patients. No rebleeding of WEB treated aneurysms was reported. Safety events up to 12 months included procedural thromboembolic events in 13.3% and stroke events in 8.4% of patients, with low 12 month mortality (1.4%) and morbidity (6.4%), mostly related to the initial aneurysm rupture. Conclusions: WEB treatment provided complete protection against rebleeding and is a safe and effective option for patients with ruptured wide neck bifurcation aneurysms.

Background: Timely and accurate treatment decisions in acute ischemic stroke (AIS) are critical, particularly for intravenous thrombolysis (IVT) and mechanical thrombectomy (MT). As many patients initially present to non-specialized centers, decision-making may be delayed or inconsistent. Large language models (LLMs) have the potential to support clinical triage by integrating complex clinical and imaging information. We evaluated the diagnostic accuracy and reasoning characteristics of LLMs for IVT and MT eligibility compared with expert clinicians and real-world decisions. Methods: In this retrospective study, 80 AIS cases from two stroke centers were converted into structured clinical vignettes, including demographic, clinical, and imaging data. Four LLMs (DeepSeek R1, OpenAI o3 mini, Gemini 2.0, and LLaMA 3.3) and six stroke experts (two neurologists, four neuroradiologists) independently recommended treatment (IVT and/or MT). Ground truth was defined as the institutional treatment decision. Diagnostic accuracy was calculated separately for IVT and MT. A qualitative error analysis assessed reasoning patterns. Results: DeepSeek R1 achieved the highest MT accuracy among all models and clinicians (MT 87%), with IVT accuracy of 78%. Overall, performance was higher for MT than IVT across all groups. Neurologists achieved 81% (MT) and 80% (IVT), while neuroradiologists achieved 84% (MT) and 76% (IVT). LLM explanations for MT decisions were largely clinically plausible but diverged from real-world choices, whereas IVT errors were predominantly related to incomplete guideline adherence. Conclusions: LLMs demonstrated expert-level performance in AIS treatment decision-making, particularly for MT, with interpretable reasoning. These findings support further validation of LLM-based decision support systems in acute stroke triage, especially in remote settings.

Background: The relevance of prior antithrombotic and thrombolytic treatment for decision‐making regarding endovascular thrombectomy (EVT) for acute ischemic stroke due to large vessel occlusion with established large infarcts is uncertain. This study investigates associations of prior antithrombotic medication and thrombolysis with the efficacy and safety of EVT for acute ischemic stroke due to large vessel occlusion with established large infarct. Methods: TENSION (Efficacy and Safety of Thrombectomy in Stroke With Extended Lesion and Extended Time Window) was a prospective randomized open‐label blinded–end point clinical trial. Patients with acute ischemic stroke due to large vessel occlusion and established large infarct were randomized to EVT with medical therapy or medical therapy alone. Exposures were preadmission antithrombotic treatment with antiplatelet agents or anticoagulants and intravenous thrombolysis. The primary efficacy end point was functional outcome at 90 days. Safety outcomes included death and symptomatic intracranial hemorrhage. Results: The study included 246 patients (median age, 74 years; interquartile range, 65 to 80 years; 49% women); 124 (50%) were assigned to EVT. Of 176 patients (72%) with prior antithrombotic therapy, 75 (31%) received antiplatelets, 56 (23%) anticoagulants, and 89 (36%) intravenous thrombolysis. EVT was associated with better functional outcome in patients with (common odds ratio [cOR], 2.40 [95% CI, 1.22–4.99]) and without (cOR, 2.29 [95% CI, 1.53–3.46]) antiplatelet therapy; with (cOR, 2.45 [95% CI, 1.17–5.28]) and without (cOR, 2.12 [95% CI, 1.44–3.15]) anticoagulation; as well as receiving (cOR, 1.46 [95% CI, 0.83–2.61]) and not receiving (cOR, 2.89 [95% CI, 1.87–4.51]) thrombolysis. Interaction analyses were consistent with similar treatment effects across subgroups. Mortality and rates of symptomatic intracranial hemorrhage were similar between groups. Conclusions: Benefit and safety of EVT were not modified by prior antithrombotic/thrombolytic therapy. Preadmission exposure to antiplatelets or anticoagulants or use of intravenous thrombolysis should not exclude eligible patients with stroke from EVT. Registration: URL: https://www.clinicaltrials.gov ; Unique Identifier: NCT03094715.

Purpose: Several recent trials have shown improved functional outcomes with endovascular thrombectomy (EVT) in patients presenting with large ischaemic lesions, yet the impact of reperfusion on lesion pathophysiology in this population remains incompletely understood. We hypothesised that EVT reduces ischaemic oedema formation and that attenuation of oedema mediates functional outcome improvement beyond changes in lesion extent. Methods: We performed a secondary analysis of the randomised TENSION trial, which enrolled patients with anterior circulation ischaemic stroke and baseline ASPECTS 3–5. Oedema progression was quantified as the change in CT-based net water uptake between baseline and follow-up non-contrast CT (ΔNWU), derived from relative hypoattenuation within the infarct. Lesion extent change was assessed by the difference in ASPECTS between baseline and follow-up imaging (ΔASPECTS). Associations of ΔNWU and ΔASPECTS with 90-day modified Rankin Scale (mRS) were tested using ordinal logistic regression. Mediation analyses estimated the proportion of EVT’s treatment effect on functional outcome explained by ΔNWU and ΔASPECTS. Results: Among 177 patients, median follow-up NWU was 28.5% (IQR: 19.2–36.6) and follow-up ASPECTS was 2 (IQR: 1–3). EVT was associated with substantially lower oedema progression (ΔNWU 4.7% vs 15.9% without EVT; P < .001). Mediation analysis suggested that a model-estimated 34% of EVT-related improvement in mRS was associated with reduced oedema formation (ΔNWU), whereas 14% was associated with lesion extent change (ΔASPECTS). In a sensitivity analysis using nonparametric bootstrap with 5000 resamples, the mediation signal remained robust for ΔNWU but was substantially weaker for ΔASPECTS. Conclusion: In large-core stroke, EVT was associated with significantly attenuated oedema progression between baseline and follow-up imaging. Reduced ischaemic water uptake was strongly associated with EVT benefit on 90-day functional outcome in mediation models, supporting oedema attenuation as a plausible mechanistic pathway of EVT benefit.

Coiling remains a widely used, first-line endovascular treatment for intracranial aneurysms. However, recent large-scale evaluations are limited since the ARETA study, which assessed the safety and efficacy of aneurysm coiling in patients treated between 2013 - 2015. A detailed analysis of the INSTANT study is presented, which provides recent data on endovascular treatment of intracranial aneurysms with the OPTIMA™ coil system (Balt). INSTANT is a European, non-interventional, prospective study that assessed patients with ruptured, unruptured, or recanalized aneurysms treated with OPTIMA™. The primary endpoint was the morbi-mortality of patients treated with OPTIMA™ at 30 days, with an additional assessment at 12 months as a secondary endpoint. From April 2019 to September 2022, 294 patients (56.3±12.0 years, 186 women [63.3%]) were enrolled in 18 European centers. Aneurysms were acutely ruptured in 45.2% of cases (N=133/294) and unruptured/recanalized in 54.8% (N=161/294). The overall mortality at 30 days was 0.0% in patients with unruptured aneurysms and 3.0% (N=4/133, [95% CI:0.1-5.9]) in those with ruptured aneurysms, which were all related to SAH and its complications. Overall, morbidity at 30 days was 1.2% (N=2/161, [95% CI:0.0-3.0]) in patients with unruptured aneurysms and 21.1% (N=28/133, [95% CI:14.1-28.0]) in patients with ruptured aneurysms. No deaths or adverse events resulting in morbidity were related to OPTIMA™ or the procedure (0.0%). In the INSTANT study, treatment of intracranial aneurysms with the OPTIMA™ coil system showed low morbidity and mortality at 30 days and 12 months, unrelated to the device or procedure.

Background: Flow diversion is an effective technique for treating intracranial aneurysms (IAs), with a high rate of complete aneurysm occlusion at 1 year. As dual antiplatelet treatment (DAPT) is required, it is restricted to unruptured IA. Surface-modification (SM) flow diverters (FDs), introduced to reduce thrombogenicity, have been poorly evaluated. COATING (Coating to Optimize Aneurysm Treatment In the New Flow Diverter Generation) is the first randomized controlled trial (RCT) evaluating an SM FD (p64-MW-HPC (hydrophilic polymer coating), phenox GmbH) under single antiplatelet treatment (SAPT). Methods: We compared the treatment arm, SM p64-MW-HPC under SAPT (ticagrelor or prasugrel), to the control arm, bare p64-MW under DAPT (ticagrelor or prasugrel+aspirin), for unruptured IA management. The primary endpoint (number of diffusion-weighted imaging (DWI) lesions on MRI 48 hours (±24 hours) after the index procedure) and safety data up to 1 month post-procedure were analyzed. Results: From September 2021 to November 2024, 171 patients (female 84.8%, mean age 55±11 years) were included in 15 centers in Europe and Israel with 83 patients in the treatment arm and 88 in the control arm. The mean (±SD) number of DWI lesions within 48 hours (±24 hours) of the index procedure in the treated aneurysm territory was 6.0 (±13.28) in the HPC and 5.3 (±11.75) in the bare group (P _{non-inferiority testing} <0.0001). 1-month safety data showed no statistically significant difference in thromboembolic events between study arms. Conclusion: COATING is the first RCT to evaluate an SM FD (p64-MW-HPC) under SAPT and shows favorable safety at 1 month.

Purpose: To evaluate the prognostic utility of visual Alberta stroke program early computed tomography score (ASPECTS) and perfusion parameters obtained from automated RAPID-AI software in patients undergoing mechanical thrombectomy (MT) beyond 6 hours from stroke onset. Methods: We retrospectively analyzed 86 patients with anterior circulation large vessel occlusion who underwent non-enhanced computed tomography (NECT), multiphase computed tomography angiography, and computed tomography perfusion within 6–24 hours before thrombectomy. Visual ASPECTS (assessed by junior doctor), RAPID-ASPECTS, and RAPID-CTP parameters (ischemic core volume, penumbra, and mismatch ratio) were recorded. The primary outcome was 90-day functional independence (modified Rankin Score 0-2). Multivariable logistic regression and receiver operating characteristic analysis were used to identify independent predictors. Results: Visual ASPECTS was significantly associated with a favorable outcome (area under the curve = 0.709; optimal cut-off ≥ 6), while no perfusion-derived parameters reached statistical significance. In multivariable analysis, only visual ASPECTS (OR 0.083, 95% CI: 0.033–0.133; p = 0.001), hypertension (OR 0.252, 95% CI: 0.053–0.452; p = 0.014), and symptomatic intracranial hemorrhage (OR 0.634, 95% CI: 0.303–0.964; p < 0.001) remained independent predictors. Agreement between visual and RAPID-ASPECTS was moderate (intraclass correlation coefficient 0.67; 95% CI: 0.49–0.80; p < 0.001), but poor when dichotomized at the ≥ 6 threshold (Cohen's kappa κ = 0.18, p < 0.001). Conclusion: Visual ASPECTS outperformed perfusion-derived metrics in predicting clinical outcomes after late-window thrombectomy. These findings support the continued relevance of NECT and expert visual scoring, particularly in settings where perfusion imaging may be limited or inconsistent.

Background: The Tigertriever (Rapid Medical, Israel) is the first manually expandable stent retriever, designed to enhance clot engagement and vessel wall apposition. Despite increasing use, comparative data with the widely adopted Solitaire X device (Medtronic, USA) are limited. This study aimed to compare the safety and efficacy of Tigertriever versus Solitaire in mechanical thrombectomy (MT) for acute ischemic stroke due to large vessel occlusion. Methods: We retrospectively analyzed 346 MT procedures (May 2019–September 2024). Patients treated with Tigertriever or Solitaire X (with/without aspiration) were matched 1:1 using a nearest-neighbor approach based on age, National Institutes of Health Stroke Scale, Alberta Stroke Program Early CT Score, and occlusion site. Outcomes included procedural safety (complications, hemorrhage, mortality) and efficacy (number of passes, time to reperfusion, final modified treatment in cerebral infarction, and 3-month modified Rankin Scale) were compared, with propensity score adjustment applied in the analyses. Results: In total, 268 matched patients (134 per group) were included. Baseline characteristics were balanced, except that Tigertriever patients had longer onset-to-puncture times and more cardioembolic strokes. The Solitaire X group demonstrated a significantly higher first-pass recanalization rate ( p = 0.03; adjusted odds ratio (OR) = 1.82, 95% confidence interval (CI): 1.02–3.23, p = 0.04) and required fewer device passes to achieve successful reperfusion ( p < 0.001; adjusted OR = 0.19, 95% CI: 0.06–0.56, p = 0.002). In atherosclerotic occlusions, Tigertriever tended to have higher reperfusion and first-pass success rates and better 3-month outcomes. Overall, 90-day functional outcomes did not differ significantly. Conclusions: Tigertriever and Solitaire demonstrated comparable 3-month functional outcomes, though procedural profiles and subgroup advantages differed. Further randomized trials are warranted.

Background: Acute ischemic stroke (AIS) management has evolved substantially over the past two decades, with mechanical thrombectomy adding complexity that requires specialized centers. As many patients initially present to primary care facilities, rapihtmld and accurate triage is critical. Large language models (LLMs) may help bridge expertise gaps, especially where stroke specialists are not immediately available. This study evaluates the diagnostic accuracy and reasoning quality of four LLMs in determining eligibility for intravenous thrombolysis (IVT) and mechanical thrombectomy (MT), compared with experienced clinicians and real-world treatment decisions. Methods: We retrospectively collected 80 acute ischemic stroke cases from two stroke centers. Cases were presented to LLMs as well to clinicians as clinical vignettes containing demographic, clinical, and imaging data. Four LLMs (DeepSeek R1, OpenAI o3 mini, Gemini 2.0, LLaMA 3.3) and six stroke experts (two neurologists, four neuroradiologists) independently reviewed the cases and recommended one or more treatment strategies including IVT and MT. The ground truth was defined as the institutional treatment decision. Accuracy for MT and IVT recommendations was calculated for both LLMs and clinicians. Additionally, a qualitative error analysis evaluated the reasoning ability of LLMs. Results: Open-source reasoning model DeepSeek R1 outperformed all other LLMs and clinicians for MT (87% accuracy) and achieved 78% accuracy for IVT. Across models, accuracy was generally higher for MT than for IVT. Neurologists reached 81% (MT) and 80% (IVT), while neuroradiologists achieved 84% (MT) and 76% (IVT). Reasoning analysis for MT recommendations showed that most errors were clinically reasonable but differed from real-world decision, whereas IVT errors were primarily due to guideline non-adherence. Conclusions: LLMs can match or even exceed expert clinician performance in MT and IVT eligibility decisions, while providing transparent reasoning. These findings support prospective evaluation of LLM-based decision support in acute stroke care, especially in settings without immediate specialist expertise.