Frédéric Clarençon

BACKGROUND AND OBJECTIVES: The Woven Endobridge (WEB) and the Contour Neurovascular System (Contour) are both intrasaccular devices used to treat cerebral aneurysms. We compared outcomes of these 2 devices using data from 2 large registries. METHODS: Data were sourced from the WorldWideWEB Consortium, which included 1363 cases treated with WEB from 2017, and a registry of 277 Contour cases from 10 European centers starting the same year. Patient demographics, aneurysm characteristics, procedural specifics, and outcomes were analyzed. Propensity score matching was applied for comparison. RESULTS: Before matching, the Contour group had more men (37.9% vs 30.8%), more asymptomatic cases (83.4% vs 70.3%), and fewer acute subarachnoid hemorrhage cases (10.8% vs 26.2%). After matching, no significant differences were found in demographics or aneurysm characteristics between groups. The median age was 60 years, and median aneurysm dimensions were comparable. Logistic regression showed no significant differences between WEB and Contour in achieving complete occlusion (odds ratio [OR] = 1.01, 95% CI, 0.67-1.52, P = .971), adequate occlusion (OR = 0.85, 95% CI, 0.41-1.76, P = .665), or achieving modified Rankin Scale 0 to 2 at last follow-up (OR = 0.48, 95% CI, 0.21-1.02, P = .064). Retreatment (OR = 2.23, P = .086), thromboembolic complications (OR = 0.75, P = .452), and adjunctive treatment use (OR = 1.93, P = .141) were also similar. CONCLUSION: The WEB and Contour demonstrated comparable clinical and angiographic outcomes in this large multicenter study comprised majority small, asymptomatic cerebral aneurysms.

Background: Covert brain infarction is a frequent incidental neuroradiological finding increasingly recognized as clinically relevant due to its association with stroke, cognitive decline, and other adverse outcomes. However, substantial uncertainty remains regarding its optimal assessment and management, and existing guidelines provide limited and heterogeneous recommendations. We aimed to develop an international expert consensus on the evaluation and management of covert brain infarction using a modified Delphi methodology. Methods: A modified Delphi process was conducted with an international, multidisciplinary panel of 21 experts from 15 countries, including neurologists, neuroradiologists, neuroepidemiologists, and geriatricians. An initial questionnaire was developed from a structured literature review and identified clinical practice gaps. The survey included 91 statements across four domains: (1) prognosis, etiology, and screening; (2) neuroimaging-based management and follow-up; (3) cardiac evaluation; and (4) pharmacological management. Two iterative rounds were conducted, with anonymized responses, controlled feedback, and structured discussion. A 5-point Likert-type scale was used. Consensus was defined a priori as ⩾ 70% agreement. Results: Consensus was reached on 33/91 statements (36.3%), moderate agreement on 43/91 (47.2%), and no consensus on 15/91 (16.5%). The panel agreed that covert brain infarction is associated with increased risk of ischemic stroke, cognitive impairment, and dementia, and that risk is higher with multiple lesions. Consensus supported targeted clinical evaluation, including a cardiac workup with transthoracic echocardiography in all patients and vascular imaging in selected cases. Routine population screening and systematic postprocedural imaging were not supported. Regarding management, consensus favored optimizing vascular risk factors, particularly strict blood pressure control in hypertensive patients. There was no consensus on routine antiplatelet therapy for incidental covert brain infarction, and anticoagulation was generally not supported in the absence of cardioembolic indications. Lipid-lowering therapy showed limited consensus regarding specific benefits for covert brain infarction–related outcomes. Conclusion: This Delphi consensus highlights substantial variability in the perceived management of covert brain infarction and identifies areas of convergence, particularly in risk stratification and control of vascular risk factors. Key uncertainties remain regarding antithrombotic strategies, lipid-lowering therapy, and long-term surveillance. These results provide a pragmatic, expert-based framework to support clinical decision-making and further highlight the need for prospective studies and randomized trials in this rapidly evolving field.

Rescue stenting (RS) is increasingly used for intracranial artery stenosis-related large vessel occlusion (ICAS-LVO), but optimal patient selection remains uncertain. We investigated the baseline and procedural factors associated with receiving RS and whether they modified the association between RS and clinical outcome. This retrospective multicenter study included patients with middle cerebral artery (MCA) ICAS-LVO treated with mechanical thrombectomy (MT) alone or MT followed by RS. Baseline and procedural characteristics associated with receiving RS were identified using multivariable logistic regression and incorporated into inverse probability of treatment weighting models to assess treatment-effect heterogeneity for the 90-day modified Rankin Scale score. Among 264 patients, 193 received RS and 71 MT alone. MT failure, severe stenosis (> 75%), and higher baseline Alberta Stroke Program Early CT Score (ASPECTS) were independently associated with receiving RS. Both MT failure (interaction OR 0.28, 95% CI 0.10–0.83; p for interaction = 0.02) and severe stenosis (interaction OR 0.13, 95% CI 0.03–0.53; p for interaction = 0.004) significantly modified the association between RS and clinical outcome, whereas baseline ASPECTS did not. Within the MT failure subgroup, a significant interaction between severe stenosis and ASPECTS was observed (interaction OR 0.08, 95% CI 0.02–0.38; p for interaction = 0.002), suggesting a more favorable association between RS and outcome at higher ASPECTS values in patients with severe stenosis. In MCA ICAS-LVO, RS may be associated with more favorable outcomes in patients with MT failure, particularly in the presence of severe residual stenosis and preserved ASPECTS. These findings support a more selective approach to RS and warrant prospective validation.

Background: The exclusion treatment of Spetzler–Martin grade (SMG) IV–V brain arteriovenous malformations (bAVMs) remains controversial. This study evaluates the safety and effectiveness of endovascular treatment (EVT) for SMG IV–V bAVMs, either as a standalone strategy or as part of multimodal management. Methods: A retrospective single-center observational cohort study of consecutive adult patients with SMG IV–V bAVMs treated with EVT between 1998 and 2024 was conducted. Baseline characteristics, procedure-related complications, clinical outcomes, and angiographic follow-up were recorded. Independent risk factors for EVT-related complications were analyzed using binary logistic regression. Results: A total of 73 patients with 73 SMG IV–V bAVMs were included. The median age was 36 (IQR 28–47) years, and 29 (39.7%) bAVMs were ruptured at presentation. Complete angiographic obliteration by EVT alone in intention to cure was achieved in 6/33 patients (18.2%). Overall, complete angiographic obliteration was achieved in 33 patients (45.2%), either by EVT alone or within a multimodal treatment strategy. EVT-related major complications (shift in modified Rankin Scale score of ≥2 or death) occurred in eight patients (11.0%). The presence of a flow-related proximal aneurysm was independently associated with EVT-related complications (OR 4.47; 95% CI 1.18 to 16.98; P=0.028). Conclusions: In this single-center retrospective series, EVT for SMG IV–V bAVMs was associated with a substantial procedural risk and achieved complete obliteration only in a limited proportion of patients when used as a standalone treatment. Within a multimodal management strategy higher angiographic exclusion rates were observed, although it remained associated with substantial morbidity.

BACKGROUND: Endovascular thrombectomy (EVT) for distal and medium vessel occlusion stroke remains uncertain. We aimed to develop a medium and distal mechanical thrombectomy score integrating clinical need and procedural risk to guide patient selection. METHODS: This retrospective cohort analysis used an international distal and medium vessel occlusion stroke registry spanning the study period of 2017 to 2023. Patients with acute distal and medium vessel occlusion stroke who received medical management (MM) or EVT across 37 stroke centers were included, and those with baseline modified Rankin Scale score of ≥3 or those with missing covariable data were excluded. Multivariable logistic regression identified predictors of poor functional outcome (modified Rankin Scale score >2 at 90 days) in the MM cohort and predictors of EVT failure/complications in the EVT cohort. Predictors of poor outcome on MM were assigned positive weights (clinical need); predictors of EVT failure/harm were assigned negative weights (procedural risk). The medium and distal mechanical thrombectomy score summed these weighted points. Interaction analysis assessed the heterogeneity of EVT effect by score. RESULTS: A total of 1217 patients were identified, and 1007 were included (EVT: 822, MM: 185; median age 73 years; 41% female). Higher National Institutes of Health Stroke Scale score (+1 per point) and lack of intravenous thrombolysis (+7) predicted poor MM outcomes. In the EVT cohort, older age (−1 per 15 years above 25), absence of hypertension (−2), and absence of atrial fibrillation (−2) predicted failure/complications. The medium and distal mechanical thrombectomy score (range −8 to 49) significantly modified EVT effect versus MM ( P _interaction =0.048). In high-score patients (≥15; n=293), EVT yielded a better 90-day modified Rankin Scale score than MM (median, 3 versus 4; P =0.009). Conversely, in low-score patients (P =0.014). CONCLUSIONS: The medium and distal mechanical thrombectomy score is a pragmatic tool that identifies patients with distal and medium vessel occlusion most likely to benefit from EVT while minimizing risk, supporting patient-centered decisions and future trial design.

Background: Super-large-bore aspiration catheters are designed to improve clot engagement and aspiration efficiency during mechanical thrombectomy. However, multiple 0.088-inch platforms are now available, and device-specific clinical performance cannot be inferred from catheter size alone. We report the first multicenter real-world experience with SOFIA 88. Methods: This retrospective multicenter European registry included consecutive patients treated with SOFIA 88 for anterior circulation large vessel occlusion involving the internal carotid artery or M1. The primary outcome was successful catheter advancement to the thrombus-vessel interface. Angiographic outcomes included first-pass effect (extended Thrombolysis in Cerebral Infarction (eTICI)≥2c after one pass), final complete reperfusion (eTICI 2c-3), and final successful reperfusion (eTICI≥2b). Safety outcomes included procedural complications, embolization to new territory, intracranial hemorrhage, and symptomatic intracranial hemorrhage. Results: Eighty-one patients from eight centers were included. SOFIA 88 reached the thrombus–vessel interface in 67/81 cases (82.7%), most often using smaller-catheter support (57/81, 70.4%). SOFIA 88 standalone first-pass effect occurred in 32/81 patients (39.5%) using the full real-world cohort denominator and in 32/67 patients (47.8%) among cases with successful SOFIA 88 target access. Final complete and successful reperfusion was achieved in 67/81 (82.7%) and 79/81 (97.5%) patients, respectively. Procedural adverse events occurred in 3/81 (3.7%), embolization to new territory in 1/81 (1.2%), and symptomatic intracranial hemorrhage in 5/81 (6.2%). No device-related adverse events occurred. Conclusions: SOFIA 88 showed feasible target access, high final reperfusion, favorable standalone first-pass performance after successful target access, and acceptable early safety. Further prospective studies are warranted to define optimal patient selection, delivery strategies, and the role of SOFIA 88 in contemporary thrombectomy practice.

Background The benefits and risks of intravenous thrombolysis (IVT) with alteplase for acute ischemic stroke (AIS) beyond 4.5 h are unclear. Decision-making is further limited by the lack of comparisons between imaging strategies used for patient selection, including magnetic resonance imaging with diffusion-weighted imaging (MRI/DWI) and perfusion-guided approaches such as MRI with perfusion-weighted imaging (MRI/PWI) or computed tomography perfusion (CTP). This study aims to evaluate the efficacy and safety of alteplase administered beyond 4.5 h and to compare MRI/DWI- and perfusion-guided IVT. Methods Databases were searched for RCTs enrolling AIS patients treated with alteplase beyond 4.5 h. Efficacy outcomes included excellent (mRS 0–1) and favorable (mRS 0–2) functional outcomes at 90 days, and major neurological improvement up to 72 h. Safety outcomes included any intracranial hemorrhage (aICH), symptomatic ICH (sICH), parenchymal hemorrhage (PH), and 90-day mortality. Results Seven RCTs comprising 1685 patients were included. There were no differences between imaging strategies in any efficacy or safety outcome. Alteplase administered beyond 4.5 h was associated with higher rates of excellent (RR 1.24; 95% CI 1.12–1.38) and favorable (RR 1.17; 95% CI 1.09–1.26) functional outcomes, and increased major neurological improvement (RR 1.28; 95% CI 1.11–1.49). The risks of aICH (RR, 2.82; 95% CI 1.17–6.80), sICH (RR, 3.31; 95% CI 1.42–7.74), and PH (RR, 2.95; CI 95% 1.33–6.53) were higher in the alteplase group, while mortality showed no difference (RR 1.27; 95% CI 0.91–1.76). Conclusion This network meta-analysis did not detect a statistically significant difference between perfusion-guided and DWI/FLAIR mismatch–guided selection; however, this comparison was indirect, based on a limited number of trials, and not powered to demonstrate equivalence, and should not be interpreted as evidence that the two paradigms are interchangeable.

Introduction Intravenous thrombolysis (IVT) is the established treatment for acute ischemic stroke (AIS) when administered within 4.5 h of the last known well (LKW) status. However, this narrow therapeutic window limits the number of patients eligible for treatment. In this context, tenecteplase (TNK) is being investigated as an alternative thrombolytic agent in the extended time window. Objective The objective of this study was to evaluate the safety and efficacy of intravenous TNK in patients with AIS treated in the extended time window (beyond 4.5 h from LKW) compared with best medical treatment (BMT) without IVT. Methods We conducted a systematic literature review and meta-analysis of patients with AIS presenting beyond 4.5 h from LKW treated with TNK or BMT in randomized controlled trials (RCTs). The safety outcomes included: (1) symptomatic intracranial hemorrhage (sICH), (2) mortality at 90 days, (3) any intracranial hemorrhage (ICH), and (4) parenchymal hemorrhage type 2 (PH2). The efficacy outcomes included: (1) excellent functional outcome (modified Rankin scale [mRS] 0–1) at 90 days, (2) functional independence (mRS 0–2) at 90 days, and (3) early neurological improvement. An analysis based on odds ratios (OR) with 95% confidence intervals (CI) under a random-effects model was used for data pooling. Heterogeneity was assessed using the Q test and its P-value, with the magnitude evaluated by I² values. Results A total of 6 RCTs including 2297 patients were analyzed, with 1152 patients receiving TNK and 1145 receiving BMT. Compared with BMT, TNK administered in the extended time window was associated with significantly higher rates of excellent functional outcomes (mRS 0–1: OR 1.40, 95% CI 1.18–1.67; P < 0.001), functional independence (mRS 0–2: OR 1.27, 95% CI 1.07–1.51; P = 0.006), and early neurological improvement (OR 3.21, 95% CI 1.82–5.66; P < 0.001). TNK was associated with a significant increase in sICH (OR 2.34, 95% CI 1.11–4.95; P = 0.026). No significant differences were observed in 90-day mortality (OR 1.17, 95% CI 0.89–1.55), any ICH (OR 1.61, 95% CI 0.37–6.95), or PH2 (OR 1.81, 95% CI 0.90–3.64). Conclusions In patients with AIS treated beyond 4.5 h from symptom onset, intravenous TNK significantly improves functional outcomes and early neurological recovery compared with BMT, without a significant increase in mortality. Although sICH was significantly increased, absolute rates remained low. These findings support the potential role of tenecteplase as an effective thrombolytic option in the extended time window for carefully selected patients. Registration PROSPERO identifier no. CRD420251060492.

Background: Tentorial dural arteriovenous fistulas (TDAVFs) are rare but high risk vascular lesions. Although endovascular embolization is often the preferred treatment, large scale data on efficacy and safety are limited. Objective: To investigate the efficacy and safety of endovascular treatment for TDAVFs in a large, retrospective, multicenter cohort, and to analyze lesion characteristics and outcomes according to TDAVF location. Methods: Clinical, radiological, and interventional data from 585 patients treated in 32 international centers in 758 endovascular treatment sessions between 2012 and 2022 were analyzed. Patient demographics, fistula characteristics, endovascular treatment techniques, complications, and outcomes were assessed. Efficacy was measured by occlusion rates, safety by symptomatic complications, and modified Rankin Scale (mRS) scores. Results: In 31.3% of cases TDAVFs initially presented with hemorrhage, including 12.8% in low grade TDAVFs (absence of cortical venous reflux). Transarterial embolization was the primary approach in 84.7% of sessions. Complete occlusion was achieved in 74.2% of cases after the last treatment and 85.7% at the last imaging follow-up (mean 20.9 months). Symptomatic complications occurred in 9.4% of patients, with 2.6% permanent deficits and 1.0% mortality. At the last clinical follow-up (mean 30.6 months), 89.2% of patients had good functional outcome (mRS score 0–2). Location was significantly associated with fistula grade (eg, galenic and tentorial sinus TDAVFs being more often high grade, and torcular TDAVFs being more often low-grade). Conclusions: This large multicenter series demonstrated high occlusion rates, favorable functional outcomes, and acceptable complication rates, supporting endovascular therapy as a treatment of choice for TDAVFs. Considerable hemorrhage rates in low grade TDAVFs support the treatment even in the absence of cortical venous reflux.