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Background: Regression or disappearance of MRI abnormalities is usually observed after treatment of spinal dural arteriovenous fistulae (sDAVF)., Objective: To assess the correlation between spinal MRI (sMRI) changes with sDAVF exclusion and clinical outcome., Methods: Imaging data of patients treated with endovascular embolization for sDAVF between 2007 and 2023 were retrospectively analyzed. Spinal cord edema and perimedullary flow voids at baseline and 3-months' follow-up were compared between patients with and without sDAVF persistent occlusion and clinical improvement on the Aminoff and Logue Scale., Results: Twenty-five patients were included in this study. At 3-months' follow-up, regression of spinal cord edema was significantly associated with sDAVF persistent occlusion (P=0.038). The combination of edema and flow voids regression was significantly associated with higher odds of a cured sDAVF (P<0.001) and clinical improvement (P<0.01). Improvement in the combination of the above-mentioned sMRI signs presented high sensitivity (100% (95% CI 78.20%-100%)) and negative predictive value (100% (95% CI 47.82%-100%)) for the detection of sDAVF cure compared with the criterion standard (digital subtraction angiography (DSA))., Conclusions: Patients with both spinal cord edema and flow voids regression at 3 months were more likely to present with a persistent occlusion of sDAVF and clinical improvement after endovascular embolization. Patients without sMRI improvement should be referred for DSA to seek recurrence of sDAVF., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Mechanical thrombectomy (MT) has become a standard treatment for acute ischemic strokes (AIS). However, MT failure occurs in approximately 10-30% of cases, leading to severe repercussions (with mortality rates up to 40% according to observational data). Among the available rescue techniques, rescue intracranial stenting (RIS) appears as a promising option., Objective: This trial is poised to demonstrate the superiority of RIS in addition to the best medical treatment (BMT) in comparison with BMT alone, in improving the functional outcomes at 3 months for patients experiencing an AIS due to a large vessel occlusion refractory to MT (rLVO)., Methods: Permanent Intracranial STenting for Acute Refractory large vessel occlusions (PISTAR) is a multicenter prospective randomized open, blinded endpoint trial conducted across 11 French University hospitals. Adult patients (≥18 years) with an acute intracranial occlusion refractory to standard MT techniques will be randomized 1:1 during the procedure to receive either RIS+BMT (intervention arm) or BMT alone (control arm)., Results: The primary outcome is the rate of good clinical outcome at 3 months defined as a modified Rankin Scale score ≤2 and evaluated by an independent assessor blinded to the randomization arm. Secondary outcomes include hemorrhagic complications, all adverse events, and death. The number of patients to be included is 346. Two interim analyses are planned with predefined stopping rules., Conclusion: The PISTAR trial is the first randomized controlled trial focusing on the benefit of RIS in rLVOs. If positive, this study will open new insights into the management of AIS., Trial Registration Number: NCT06071091., Competing Interests: Competing interests: NS reports a conflict of interest with Medtronic, Balt Extrusion, Microvention (consultant). FC reports a conflict of interest with Medtronic, Balt Extrusion (consultant), ClinSearch (core laboratory), Penumbra, Stryker (payment for reading), and Artedrone (board). The other authors report no conflicts of interest., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Competing Interests: Competing interests: The authors declare no competing interests.

The incorporation of the glymphatic clearance system in the study of brain physiology aids in the advancement of innovative diagnostic and treatment strategies for neurological disorders. Exploring the glymphatic system across (from) neurological and (to) metabolic diseases may provide a better link between obesity and neurological disorders. Recent studies indicate the role of metabolic dysfunction as a risk factor for cognitive decline and neurological disorders through the disruption of the glymphatic system. Further investigation into how metabolic dysfunction disrupts glymphatic homeostasis and the domino effects on the neurovascular landscape, including neurovascular uncoupling, cerebral blood flow disruptions, blood-brain barrier leakage, and demyelination, can provide mechanistic insights into the link between obesity and neurological disorders., Competing Interests: Declaration of interests No interests are declared., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background and Purpose: So-called contrast-induced encephalopathy (CIE) is a rare but worrying condition occurring after cerebral angiography or neuroendovascular interventions using iodine contrast media. This study aimed to compare cerebral iodine concentrations in patients suspected of having CIE after endovascular procedures to those in matched controls., Methods: This is a retrospective monocentric study of 25 suspected CIE patients in a tertiary care teaching hospital diagnosed from June 2017 to February 2024. Cerebral multispectral computed tomography (CT) iodine mean concentrations were measured and compared with 1:1 matched controls using the CT constructor's workstation in the whole brain and in specific regions of interest (ROIs) corresponding to a vascular territory downstream of the procedure. Concentration values were compared with paired samples t‑test., Results: During the study period, 1097 patients underwent aneurysm embolization and 137 arteriovenous malformation (AVM) embolization procedures. So-called CIE was suspected in 25 patients after aneurysm or AVM embolization (2%). Mean iodine concentrations in the procedure vascular territory ROIs were higher in suspected CIE cases (mean 543 ± 147 µg/cm 3 ) compared to matched controls (mean 463 ± 141 µg/cm 3 ; p = 0.01). Whole brain mean iodine concentrations were modestly higher in CIE patients compared to controls across all subgroups, without reaching statistical significance., Conclusions: CIE may be associated with modest increase in CT iodine concentration in the procedure vascular territory after neurointerventional procedures. The underlying pathophysiology of this condition remains uncertain and merits further investigation., Key Messages: Contrast-induced encephalopathy (CIE) is known as a rare neurologic condition following iodine contrast media use in neuroendovascular interventions, with unclear pathophysiology., What This Study Adds: This study provides evidence that suspected CIE is associated with higher cerebral iodine concentrations in affected vascular territories, a novel quantifiable change. Implications for research, practice, or policy: These findings suggest the potential for iodine concentration monitoring to refine CIE diagnosis and prevention strategies in clinical practice., Competing Interests: Conflict of interest S. Mouyal, L. Chougar, A. Jacquens, S. Lenck, B. Mathon, K. Premat, G. Marnat, Y. Ducos, G. Quarta Colosso, H. Gortais, E. Rius, R. Coudert, V. Degos, J. Allard, N.-A. Sourour, F. Clarençon and E. Shotar declare that they have no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.)

Background: Mechanical thrombectomy (MT) is an effective treatment for acute ischemic stroke from large vessel occlusion (LVO). While embolization to a new territory (ENT) after MT is well-documented, data on embolization in the same distal territory (EDT) are limited. Achieving modified Treatment In Cerebral Infarction (mTICI) 3 reperfusion presents significant clinical benefits over mTICI 2b/2c, necessitating strategies to reduce both ENT and EDT. Previous studies suggest higher rates of EDTs with contact aspiration compared with stentrievers. However, comprehensive comparison studies in clinical practice are scarce. This study compares the rates of overall clot emboli (OCE) between these MT strategies., Methods: A retrospective, multicenter observational study was conducted at four university hospitals in France from January 2015 to November 2019. Adult patients (≥18 years) with acute ischemic stroke due to LVO, treated with either contact aspiration (ADAPT, A Direct Aspiration First Pass Technique) or stentrievers, specifically using the Embotrap device to maintain sample homogeneity, were included. Digital subtraction angiography was used for imaging, with two independent, blinded reviewers assessing OCE post-first MT pass. Propensity score full matching and independent sample testing were employed to evaluate OCE after the first MT pass., Results: A significant difference in OCE rates was observed between contact aspiration and stentriever techniques, with the stentriever technique resulting in fewer embolic events compared with ADAPT, based on a propensity score analysis that accounts for key confounding factors., Conclusion: A statistically significant reduction in embolic events was observed with the stentriever technique compared with contact aspiration. These results suggest that the stentriever method may offer a safer profile in terms of embolic risk for LVO interventions, and should be considered over contact aspiration when embolic risk is a primary concern, while also considering individual patient factors., Competing Interests: Competing interests: K Janot reports consulting fees for Balt. N-A Sourour reports conflict of interest with Medtronic, Balt (consulting fee or honorarium, non-related to the study). F Clarençon reports conflict of interest with Medtronic, Balt Extrusion (consultant; non-related to the study), ClinSearch (core lab; non-related to the study), Penumbra, Stryker (payment for reading; non-related) and Artedrone (Board; non-related to the study). The other authors did not report any conflict related to this study., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background and Objectives: Endovascular embolization of brain arteriovenous malformations (AVMs) is sometimes intentionally partial, in the case of staged treatment for instance. Residual AVMs may be prone to angioarchitectural modification during follow-up. The objective of this work is to evaluate the nature and extent of these modifications., Methods: We performed a retrospective monocentric study on a cohort of adult patients treated by incomplete endovascular embolization for ruptured and unruptured AVMs with an available angiographic follow-up, without any intervening confounding event between the 2 angiographic examinations. AVM angioarchitectural modifications (arterial, nidal, and venous) were analyzed. Clinical and radiological data were tested in univariate analyses for association with the occurrence of AVM regression or progression., Results: Eighty-two partial embolization sessions in 57 patients were included in the study. A 40% (33/82) rate of modification was found on follow-up, with 23/82 (28%) controls showing at least one angioarchitectural regression feature and 15/82 (18.3%) showing at least one angioarchitectural progression item. Nidal growth was the most frequent modification occurring after 12/82 (14.6%) embolizations. The only factor associated with nidal volume growth was a longer time interval between embolization and follow-up (median [IQR]: 190 [250] days vs 89.5[133] days in the subgroup without nidal growth; P = .02). Specific modifications of arterial supply, nidal anatomy, and venous drainage were identified and documented., Conclusion: Angioarchitectural modifications (both progression and regression) of brain AVMs are frequent findings after partial embolization. Nidal volume growth is associated with longer time intervals between embolization and follow-up., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Purpose: This study aims to explore the impact of ultra-early neurological deterioration (U-END) on the outcome (mortality and poor neurological status) following a brain arteriovenous malformation (BAVM) rupture and identify determinants of U-END., Methods: Patients with BAVM ruptures admitted to a single tertiary care center were retrospectively reviewed. U-END was defined as a worsening by two or more points on the Glasgow Coma Scale (GCS). U-END was tested as a potential predictor of in-hospital mortality and poor outcomes. Univariate and multivariate analyses were performed to identify determinants of U-END. Patients with U-END were also matched and compared with BAVM rupture controls presenting with a GCS close or equal to either their initial or their lowest GCS., Results: A total of 248 patients with BAVM ruptures met the inclusion criteria, with 39 (15.7%) patients presenting with U-END. U-END was not associated with and was not an independent predictor of in-hospital mortality (12.8 vs. 10.5% in the rest of the study population; p  = 0.67) or poor outcomes (39.5 vs. 36.9%; p  = 0.77). The only independent determinants of U-END were hydrocephalus (OR 2.6 [95%CI, 1.1-6.4]; p  = 0.03) and intraventricular hemorrhage (IVH; OR 3.5 [95%CI, 1.1-11.7]; p  = 0.04). When compared to the initial GCS control group, U-END patients more often presented with IVH (89.5 vs. 64.1%; p  = 0.009) and hydrocephalus (73 vs. 38.5%; p  = 0.003). When compared to the lowest GCS control group, U-END patients had lower early S100B serum levels (0.35 ± 0.37 vs. 0.83 ± 1; p  = 0.009) and a lower rate of poor outcome (39.5 vs. 64.9%; p  = 0.03)., Conclusion: Ultra-early neurological deterioration in ruptured BAVMs did not result in increased mortality or poor outcomes and was most often related to IVH and hydrocephalus., Competing Interests: FC reports conflict of interest (unrelated) with Medtronic, Guerbet, Balt Extrusion (payment for readings), and Codman Neurovascular (core lab). N-AS is consultant for Medtronic, Balt Extrusion, and Microvention (unrelated to the study). ES is principal investigator of a randomized controlled trial related to chronic subdural hematoma embolization financed by a PHRC-IR public grant (unrelated). The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Shotar, Chiaroni, Haffaf, Cortese, Jacquens, Garzelli, Allard, Elhorany, Amouyal, Mathon, Nouet, Premat, Lenck, Sourour, Degos and Clarençon.)

Background: Spinal arteriovenous fistulas can be treated either by surgery or by endovascular means, using different strategies. The main drawback of embolization is the risk of recurrence. Our objective is to evaluate the angiographic occlusion rate and the predictive factors of angiographic cure of spinal arteriovenous fistulas at 3 months or more after embolization., Methods: This is a retrospective single-center study including 38 consecutive patients with spinal arteriovenous fistulas treated by embolization as first-line treatment. We reviewed clinical and imaging data, complications, and the immediate angiographic occlusion rate of the fistulas, and at 3 months or more after the embolization., Results: A total of 45 embolization procedures were performed: 30 procedures using glue, 15 using Onyx by 'pressure cooker' or 'balloon pressure' techniques. We observed no statistically significant difference between the two groups concerning the immediate angiographic occlusion rate (87% in both groups; P>0.9), as well as for periprocedural complication rates. The angiographic occlusion rate at 3 months or more was higher in the Onyx 'combined' techniques treated group (87% vs 40%, P=0.007). The use of Onyx 'combined' techniques was independently associated with angiographic cure at 3 months after embolization (P=0.029). No other factors were identified as predictive of angiographic cure and clinical recovery after embolization procedures, nor were any predictive factors identified for the occurrence of periprocedural complications., Conclusion: Embolization of spinal arteriovenous fistulas with Onyx using 'combined' techniques appears to be safe and associated with a higher rate of angiographic occlusion at 3 months than regular embolization with glue., Competing Interests: Competing interests: Professor F Clarençon reports conflict of interest with Medtronic, Guerbet, Balt Extrusion, Penumbra (payment for readings; non-related to the study), Codman Neurovascular and Microvention (core lab; non-related to the study). Dr Nader-Antoine Sourour is consultant for Medtronic, Balt Extrusion, Microvention, stock/stock options: Medina. The other authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper. The manuscript is not supported by industry., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Traumatic intracranial aneurysm (TICA) is a rare and aggressive pathology that requires prompt treatment. Nevertheless, early vascular imaging following head trauma may yield falsely negative results, underscoring the importance of subsequent imaging within the first week to detect delayed TICAs. This study aims to report our experience with delayed TICAs and highlight the clinical importance of repeated angiographic screening for delayed TICAs. In this retrospective analysis, we evaluated patients managed for a TICA at a tertiary care teaching institution over the last decade. Additionally, we conducted a systematic review of the literature, following the PRISMA guidelines, on previously reported TICAs, focusing on the time lag between the injury and diagnosis. Twelve delayed TICAs were diagnosed in 9 patients. The median time interval from injury to diagnosis was 2 days (IQR: 1-22 days), and from diagnosis to treatment was 2 days (IQR: 0-9 days). The average duration of radiological follow-up was 28 ± 38 months. At the final follow-up, four patients exhibited favorable neurological outcomes, while the remainder had adverse outcomes. The mortality rate was 22%. Literature reviews identified 112 patients with 114 TICAs, showcasing a median diagnostic delay post-injury of 15 days (IQR: 6-44 days), with 73% diagnosed beyond the first week post-injury. The median time until aneurysm rupture was 9 days (IQR: 3-24 days). Our findings demonstrate acceptable outcomes following TICA treatment and highlight the vital role of repeated vascular imaging after an initial negative computed tomography or digital subtraction angiography in excluding delayed TICAs., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Non-ischemic cerebral enhancing (NICE) lesions following aneurysm endovascular therapy are exceptionally rare, with unknown longitudinal evolution., Objective: To evaluate the radiological behavior of individual NICE lesions over time., Methods: Patients included in a retrospective national multicentric inception cohort were analyzed. NICE lesions were defined, using MRI, as delayed onset punctate, nodular, or annular foci enhancements with peri-lesion edema, distributed in the vascular territory of the aneurysm treatment, with no other confounding disease. Lesion burden and the longitudinal behavior of individual lesions were assessed., Results: Twenty-two patients were included, with a median initial lesion burden of 36 (IQR 17-54) on the first MRI scan. Of the 22 patients with at least one follow-up MRI scan, 16 (73%) had new lesions occurring mainly within the first 200 weeks after the date of the procedure. The median number of new lesions per MRI was 6 (IQR 2-16). Among the same 22 patients, 7 (32%) had recurrent lesions. The median persistent enhancement of a NICE lesion was 13 weeks (IQR 6-30). No factor was predictive of early regression of enhancement activity with lesion regression kinetics mainly being patient-dependent., Conclusions: The behavior of individual NICE lesions was found to be highly variable with an overall patient-dependent regression velocity., Competing Interests: Competing interests: FC reports conflict of interest with Medtronic, Guerbet, Balt Extrusion (payment for readings), Codman Neurovascular (core laboratory). N-AS is consultant for Medtronic, Balt Extrusion, Microvention; stock/stock options: Medina. The other authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper. The manuscript is not supported by industry., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background and Purpose: Delayed radial artery occlusion (dRAO) is a frequent complication after transradial access (TRA) for neurointervention when using standard large guide catheters. The RIST 079 guide catheter (RIST GC) is the first catheter designed for TRA in neurointervention. We aimed to assess the rate of dRAO after intracranial aneurysm (IA) treatment using the RIST GC., Methods: Patients treated for an IA using TRA and the RIST GC between June 2021 and November 2022 were referred to a systematic US-doppler assessment of the radial artery patency at 3-month follow-up. Patients with and without dRAO were compared to identify risk factors., Results: Twenty-two patients were included in the analysis. At 3-months follow up, 6 patients (27.3 %) presented with dRAO. Four patients were asymptomatic and 2 experienced post-operative radial hematoma and wrist pain. There was a tendency towards younger age, longer procedure duration and higher rate of forearm hematoma in patients with dRAO. Navigation using the RIST GC was successful in 90.9 % of cases. Intracranial access failures and navigation complications were all related to left internal carotid artery navigation., Conclusions: At 3-month follow up, 27.3 % of patients treated for IA using TRA with the RIST GC presented dRAO., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial or personal relationships that could be viewed as influencing the work reported in this paper., (Copyright © 2023. Published by Elsevier Masson SAS.)

Objective: The pathogenesis of intracranial dural arteriovenous fistulas (icDAVFs) is controversial. Cerebral vein thrombosis (CVT) and venous hypertension are recognized predisposing factors. This study aimed to evaluate the incidence of association between icDAVF and CVT and describe baseline aggressiveness and clinical outcomes for icDAVFs associated with CVT. The authors also performed a literature review of studies reporting icDAVF associated with CVT., Methods: Two hundred sixty-three consecutive patients in two university hospitals with confirmed icDAVFs were included. A double-blind imaging review was performed to determine the presence or absence of CVT close or distant to the icDAVF. Location, type (using the Cognard classification), aggressiveness of the icDAVF, clinical presentation, treatment modality, and clinical and/or angiographic outcomes at 6 months were also collected. All prior brain imaging was analyzed to determine the natural history of onset of the icDAVF., Results: Among the 263 included patients, 75 (28.5%) presented with a CVT concomitant to their icDAVF. For 18 (78.3%) of 23 patients with previous brain imaging available, CVT preceding the icDAVF was proven (6.8% of the overall population). Former/active smoking (OR 2.0, 95% CI 1.079-3.682, p = 0.022) and prothrombogenic status (active inflammation or cancer/coagulation trouble) were risk factors for CVT associated with icDAVF (OR 3.135, 95% CI 1.391-7.108, p = 0.003). One hundred eighty-seven patients (71.1%) had a baseline aggressive icDAVF, not linked to the presence of a CVT (p = 0.546). Of the overall population, 11 patients (4.2%) presented with spontaneous occlusion of their icDAVF at follow-up. Seven patients (2.7%) died during the follow-up period. Intracranial DAVF + CVT was not associated with a worse prognosis (modified Rankin Scale score at 3-6 months: 0 [interquartile range {IQR} 0-1] for icDAVF + CVT vs 0 [IQR 0-0] for icDAVF alone; p = 0.055)., Conclusions: This was one of the largest studies focused on the incidence of CVT associated with icDAVF. For 6.8% of the patients, a natural history of CVT leading to icDAVF was proven, corresponding to 78.3% of patients with previous imaging available. This work offers further insights into icDAVF pathophysiology, aiding in identifying high-risk CVT patients for long-term follow-up imaging. Annual imaging follow-up using noninvasive vascular imaging (CT or MR angiography) for a minimum of 3 years after the diagnosis of CVT should be considered in high-risk patients, i.e., smokers and those with prothrombogenic status.

Rationale: Mechanical thrombectomy (MT) associated with the best medical treatment (BMT) has recently shown efficacy for the management of acute ischemic stroke (AIS) secondary to a large vessel occlusion. However, evidence is lacking regarding the benefit of MT for more distal occlusions., Aim: To evaluate the efficacy in terms of good clinical outcome at 3 months of MT associated with the BMT over the BMT alone in AIS related to a distal occlusion., Methods: The DISCOUNT trial is a multicenter open-label randomized controlled trial involving French University hospitals. Adult patients (⩾18 years) with an AIS involving the anterior or posterior circulation secondary to a distal vessel occlusion within 6 h of symptom onset or within 24 h if no hyperintense signal on fluid attenuation inversion recovery acquisition will be randomized 1:1 to receive either MT associated with the BMT (experimental group) or BMT alone (control group). The number of patients to be included is 488., Study Outcomes: The primary outcome is the rate of good clinical outcome at 3 months defined as a modified Rankin scale (mRS) ⩽2 and evaluated by an independent assessor blinded to the intervention arm. Secondary outcomes include recanalization of the occluded vessel within 48 h, angiographic reperfusion in the experimental group, 3-month excellent clinical outcome (mRS ⩽ 1), all adverse events, and death. A cost utility analysis will estimate the incremental cost per quality-adjusted life year (QALY) gained., Discussion: If positive, this study will open new insights in the management of AISs., Trial Registration: ClinicalTrials.gov: NCT05030142 registered on 1 September 2021., Competing Interests: Declaration of conflicting interestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: B.G. has received grants from the French Ministry of Health and is the primary investigator of the TITAN, DIRECT ANGIO, and IA-RESCUE trial, and consulting fees from Boerhinger Ingelheim, Air Liquide, MIVI, Medtronic, Microvention, and Penumbra. A.S. reports conflicts of interest with Medtronic, Balt Extrusion, and Microvention (consultant). F.C. reports conflicts of interest with Medtronic, Balt Extrusion (consultant), ClinSearch (core lab), Penumbra, Stryker (payment for reading), and Artedrone (Board). J.-C.G. reports conflicts of interest with Stryker (consultant), Medtronic (consultant), Microvention (consultant), Balt, and Intradys (consultant). I.D.-Z. reports a conflict of interest with Medtronic (honoraria for research, lecturing and acting as an advisor). G.T. reports a conflict of interest with Guerbet France (Lecturing fees). N.B. reports a conflict of interest with Stryker and QApel (consultant). I.S. reports a conflict of interest with Sanofi Synthé-Labo, Servier, Boheringer Ingelheim, Astra-Zeneca, Novonordisk, Medtronic (consultant), and BMS-Pfizer (Lecturing fees). Prof. Cognard reports a conflict of interest with Medtronic, Stryker, Microvention, Cerenovus, and MIVI (consultant). S.A. reports a conflict of interest with Boehringer Ingelheim, Astra-Zeneca, Pfizer, and Amgen (participation in advisory meetings and satellite symposia). S.A. is also the principal investigator of the Tenecteplase treatment in Ischemic Stroke (TETRIS) registry (financial support from Boehringer Ingelheim) and of the ToGiac trial (supported by a research grant from Roche-Shugai). S.R. reports conflict of interest with Boheringer Ingelheim, Bristol-Myers Squibb (scientific expertise), and Acticor (study coordination).

Background and Objective: A compact nidus is a well-known feature of good outcome after treatment in brain arteriovenous malformations (bAVM). This item, included in the "Supplementary AVM grading system" by Lawton, is subjectively evaluated on DSA. The present study aimed to assess whether quantitative nidus compacity along with other angio-architectural bAVM features were predictive of angiographic cure or the occurrence of procedure-related complications., Materials and Methods: Retrospective analysis of 83 patients prospectively collected data base between 2003 to 2018 having underwent digital subtraction 3D rotation angiography (3D-RA) for pre-therapeutic assessment of bAVM. Angio-architectural features were analyzed. Nidus compacity was measured with a dedicated segmentation tool. Univariate and multivariate analyses were performed to test the association between these factors and complete obliteration or complication., Results: Compacity was the only significant factor associated with complete obliteration in our predictive model using logistic multivariate regression; the area under the curve for compacity predicting complete obliteration was excellent (0.82; 95% CI 0.71-0.90; p < 0.0001). The threshold value maximizing the Youden index was a compacity > 23% (sensitivity 97%; specificity 52%; 95% CI 85.1-99.9; p = 0.055). No angio-architectural factor was associated with the occurrence of a complication., Conclusion: Nidus high compacity quantitatively measured on 3D-RA, using a dedicated segmentation tool is predictive of bAVM cure. Further investigation and prospective studies are warranted to confirm these preliminary results., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.)

Objective: The management of Spetzler-Martin grade (SMG) III brain arteriovenous malformations (bAVMs) may be challenging, whatever the exclusion treatment modality chosen. The purpose of this study was to evaluate the safety and effectiveness of endovascular treatment (EVT) as a first-line treatment of SMG III bAVMs., Methods: The authors performed a retrospective, two-center, observational cohort study. Cases recorded in institutional databases between January 1998 and June 2021 were reviewed. Patients who were ≥ 18 years of age, had ruptured or unruptured SMG III bAVMs, and received EVT as first-line therapy were included. Baseline characteristics of patients and bAVMs, procedure-related complications, clinical outcome according to the modified Rankin Scale, and angiographic follow-up were assessed. The independent risk factors of procedure-related complications and poor clinical outcome were assessed using binary logistic regression., Results: One hundred sixteen patients with 116 SMG III bAVMs were included. The mean age of the patients was 41.9 ± 14.0 years. The most common presentation was hemorrhage (66.4%). Forty-nine (42.2%) bAVMs were found to be completely obliterated by EVT alone at follow-up. Complications occurred in 39 patients (33.6%), including 5 (4.3%) major procedure-related complications. There was no independent predictor of procedure-related complication. Age > 40 years and poor preoperative modified Rankin Scale score were the independent predictors of poor clinical outcome., Conclusions: EVT of SMG III bAVMs provides encouraging results but needs further improvement. When the embolization procedure performed with intent to cure appears difficult and/or risky, a combined technique (with microsurgery or radiosurgery) may be a safer and more effective strategy. In terms of safety and effectiveness, the benefit of EVT (alone or included in a multimodal management strategy) for SMG III bAVMs needs to be confirmed by randomized controlled trials.

Background: Spinal arteriovenous fistulas (SAVFs) are challenging lesions to treat by endovascular means. Our purpose was to report our early experience with dual lumen balloons (DLBs) for embolization of SAVFs using ethylene vinyl alcohol (EVOH) (the so-called 'balloon pressure technique' (BPT))., Materials and Methods: During the inclusion period, 10 consecutive patients (nine men, mean age 61.6 years) underwent endovascular treatment of a SAVF (seven dural SAVFs and three epidural SAVFs) at a single institution using the BPT. DLBs were used in all cases. In seven cases (70%), a regular DLB was used, while in three cases (30%), low profile DLBs were used. EVOH was used as the liquid embolic agent in all cases. Technical and clinical complications were systematically recorded. Clinical and angiographic outcomes were systematically evaluated more than 3 months after the procedure., Results: Complete cure of the SAVF by endovascular means alone was obtained in 80% of cases (8/10). For the two patients with incomplete SAVF occlusion, surgery was successfully performed secondarily. No recurrence was found at the 3 month follow-up in the eight patients for whom complete occlusion was obtained at the end of the embolization procedure. No permanent clinical complication was recorded using the BPT. Clinical improvement was observed in 6/10 (60%) cases., Conclusion: BPT was a feasible technique, with regular or low profile DLBs, for embolization of SAVFs. Our preliminary results suggest the safety and effectiveness of this technique., Competing Interests: Competing interests: FC reports conflicts of interest with Medtronic, Guerbet, Balt Extrusion, and Penumbra (payment for readings; not related to the study), and Codman Neurovascular and Microvention (core lab; not related to the study). NS is a consultant for Medtronic, Balt Extrusion, and Microvention., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: Middle meningeal artery (MMA) particle embolization is a promising treatment of chronic subdural hematomas (CSDH). The main purpose of this study is to measure MMA proximal caliber and assess the visibility of the two main MMA branches as a surrogate for long-term distal arterial patency following MMA CSDH embolization with trisacryl gelatine microspheres (TAGM)., Methods: This is a single-center retrospective study. All patients having undergone MMA TAGM only embolization for CSDH treatment between 15 March 2018 and 6 June 2020 with an interpretable follow-up magnetic resonance imaging (MRI) examination and no confounding factors were included. Patients were compared with controls matched for age, sex and MRI machine. Two independent readers analyzed the MRI images., Results: In this study, 30 patients having undergone embolization procedures using TAGM of 36 MMAs were included. The follow-up MRI scans were performed after a mean delay of 14.8 ± 7.1 months (range 4.9-29.4 months). The mean diameter of TAGM embolized MMAs (1 mm; 95% confidence interval, CI 0.9-1.1) was significantly smaller than the mean diameter of paired control MMAs (1.3 mm; 95% CI 1.3-1.4) (p < 0.001). The mean proximal diameter of the embolized MMAs (0.9 mm; 95% CI 0.7-1.1) was significantly smaller than the mean diameter of the contralateral MMAs in the same patients (1.4 mm; 95% CI 1.3-1.6)(p < 0.001)., Conclusion: Long-term follow-up MRI demonstrated a significant impact of TAGM embolization on MMA proximal caliber as well as on the visibility of the two main MMA branches. All comparisons indicated that there was a probable lasting impact of embolization on the patency of distal branches., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.)

Purpose: Spetzler-Martin grade (SMG) I-II (low-grade) brain arteriovenous malformations (BAVMs) are often considered safe for microsurgical resection; however, the role of endovascular treatment (EVT) remains to be clarified in this indication, especially for unruptured BAVMs. The purpose of our study was to assess the safety and effectiveness of endovascular treatment as the first-line treatment for low-grade BAVMs., Methods: From our local database, we retrospectively retrieved patients with low-grade BAVMs, either ruptured or unruptured, treated by embolization as first-line treatment in our department between January 2005 and January 2020. The primary endpoint was the total obliteration rate of BAVMs, and secondary endpoints were hemorrhagic complications and final clinical outcome, assessed through shift of the modified Rankin scale, and mortality rate secondary to BAVM embolization., Results: A total of 145 patients meeting inclusion criteria and treated by EVT as first-line therapy were included in the study (82 ruptured and 63 unruptured BAVMs). Overall, complete exclusion of BAVMs was achieved in 110 patients (75.9%); 58 patients (70.7%) with ruptured and 52 (82.5%) unruptured BAVMs, including 37.9% BAVMs excluded by EVT alone (35.5% among ruptured and 44.4% among unruptured BAVMs) and 38% by combined treatment (EVT and surgery or EVT and SRS). There was no BAVM volume cut-off predictive for total obliteration by embolization alone. Early minor hemorrhagic complications were reported in 14 patients (9.6%) and early major hemorrhagic complications were reported in 5 patients (3.4%). No late hemorrhagic complications (0%) occurred; mortality rate was 0.7% (1/145 patients). Improved/unchanged mRS was reported in 137 patients (94.5%)., Conclusion: Endovascular treatment alone or associated with others exclusion techniques, might be safe and effective for complete exclusion of low-grade brain arteriovenous malformations regardless of the volume., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.)

Objective: To evaluate the feasibility, safety, and rate of radial artery occlusion (RAO) after the treatment of intracranial aneurysms using a 6F Neuron MAX (Penumbra, Alameda, CA, USA) long sheath directly into the radial artery., Methods: All consecutive patients treated for unruptured intracranial aneurysms with TRA using a 6F Neuron MAX catheter between September 2019 and May 2021 in a single tertiary center were screened. They were referred to a consultation and an ultrasound-Doppler assessment of the radial artery 3 months after treatment with the attending neuroradiologist. Patients with available assessment of the radial artery patency were included., Results: A total of 17 patients (median age: 58 years, range 35-68 years; sex ratio F/M: 15/2) were treated for intracranial aneurysms using a 6F Neuron MAX directly into the right radial artery and included. Treatment was a technical success for 16/17 (94%) patients and 1 patient (6%) required a conversion to femoral access. The median radial artery diameter at the puncture site was 2.7 mm (range 1.8-2.9mm). No symptomatic RAO was noted during follow-up. Assessment at 3 months revealed 7/17 (41%) asymptomatic RAOs., Conclusion: Even if technically feasible, the use of a 6F Neuron Max long sheath for triaxial catheterization in intracranial interventions, especially flow diversion, may be responsible for a high radial artery occlusion rate (41%). Although being asymptomatic in all cases in our series, this high occlusion rate may be a concern for further interventions. The development of dedicated radial long sheaths for neurointerventions, with external hydrophilic coating, seems necessary., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.)

Background: Little is known about incidence, time of onset, clinical presentation, and risk factors of epileptic seizure following brain arteriovenous malformation (bAVM) rupture., Methods: We performed a monocentric retrospective cohort study from January 2003 to March 2021. The main objective of this study was to determine the incidence of seizures after spontaneous bAVM rupture in nonepileptic adult patients and describe the corresponding clinical features. The secondary objective was to identify clinical, radiological, or biological predictors for the occurrence of de novo seizures after bAVM rupture., Results: Of the 296 cases of bAVM rupture registered during the study period, 247 nonepileptic patients (male 53%, median age 40) were included in the study. Fifty-nine patients (23.9%) had at least one seizure after bAVM rupture. The use of preventive antiepileptic drugs (10.3 [1.5-74.1]; P = 0.02) and decompressive craniectomy (15.4 [2.0-125]; P < 0.009) were independently associated with the occurrence of epilepsy after the bAVM rupture. The factors independently associated with the absence of any seizure after the rupture were isolated intraventricular hemorrhage (0.3 [0.1-0.99]; P = 0.04) and infratentorial location of the bAVM (0.2 [0.1-0.5]; P = 0.09). The first seizure occurred within the first year or within 5 years in, respectively, 83.1% and 98.3% of the patients., Conclusions: Epilepsy affects nearly a quarter of patients after bAVM rupture. Decompressive craniectomy represents an independent risk factor significantly associated with the occurrence of epilepsy after bAVM rupture. The introduction of preventive AEDs after rupture could be considered in these most severe patients who have a decompressive craniectomy., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.)

Background: Non-ischemic cerebral enhancing (NICE) lesions are exceptionally rare following aneurysm endovascular therapy (EVT)., Objective: To investigate the presenting features and longitudinal follow-up of patients with NICE lesions following aneurysm EVT., Methods: Patients included in a retrospective national multicentre inception cohort were analysed. NICE lesions were defined, using MRI, as delayed onset punctate, nodular or annular foci enhancements with peri-lesion edema, distributed in the vascular territory of the aneurysm EVT, with no other confounding disease., Results: From a pool of 58 815 aneurysm endovascular treatment procedures during the study sampling period (2006-2019), 21/37 centres identified 31 patients with 32 aneurysms of the anterior circulation who developed NICE lesions (mean age 45±10 years). Mean delay to diagnosis was 5±9 months, with onset occurring a month or less after the index EVT procedure in 10 out of 31 patients (32%). NICE lesions were symptomatic at time of onset in 23 of 31 patients (74%). After a mean follow-up of 25±26 months, 25 patients (81%) were asymptomatic or minimally symptomatic without disability (modified Rankin Scale (mRS) score 0-1) at last follow-up while 4 (13%) presented with mild disability (mRS score 2). Clinical follow-up data were unavailable for two patients. Follow-up MRI (available in 27 patients; mean time interval after onset of 22±22 months) demonstrated persistent enhancement in 71% of cases., Conclusions: The clinical spectrum of NICE lesions following aneurysm EVT therapy spans a wide range of neurological symptoms. Clinical course is most commonly benign, although persistent long-term enhancement is frequent., Competing Interests: Competing interests: AB reports conflicts of interest with Balt, Cerus Endovascular, Medtronic, Microvention, Penumbra, and Stryker Neurovascular. FC reports conflict of interest with Medtronic, Guerbet, Balt Extrusion (payment for readings), and Codman Neurovascular (core laboratory). N-AS is consultant for Medtronic, Balt Extrusion, and Microvention. GM reports conflicts of interest with Medtronic and Microvention. LP reports conflicts of interest with Balt, Microvention, Phenox, and Perflow. EC reports participation on the Data Safety Monitoring Board of the Atlas stent study. The other authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper. The manuscript is not supported by industry., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: In approximately 30% of the patients, brain arteriovenous malformations (bAVMs) are revealed by seizures, which may alter the patients' quality of life. Our objective was to evaluate the benefits of exclusion treatment (radiosurgery, embolization and/or surgery) on posttherapeutic epilepsy in bAVM patients without intracranial hemorrhage prior to treatment., Methods: Our retrospective observational single-center study included all consecutive adult patients with an unruptured bAVM and epilepsy, treated at our institution from 1995 to 2019 and who were followed for at least 1 year. Data on angioarchitectural characteristics of bAVMs, on epilepsy and posttreatment modified Rankin Scale (mRS) were collected. The primary endpoint was a seizure-free status (defined as Engel class IA) after exclusion treatment versus conservative management., Results: In this study one hundred and one consecutive adult patients with bAVMs, epilepsy and without bAVM rupture before any treatment were included; 21 (21%) in the conservative management group vs. 80 (79%) in the exclusion treatment group. After exclusion treatment, 55% of the patients from the group were Engel IA after treatment vs. 10% of the conservative management group (odds ratio [OR] 11.37, 95% confidence interval [CI] 2.48-107.24, p < 0.001)., Conclusion: Our results suggest that exclusion treatment in unruptured bAVMs with epilepsy is associated with a higher seizure-free rate in comparison with conservative management. Data from randomized controlled studies are necessary to confirm these findings., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.)