BACKGROUND: With the advancement of mechanical thrombectomy (MT), post-treatment diffusion-weighted imaging (DWI) lesion reversal (DWIR) has been reported. This study aimed to compare the volumes of DWI lesions and the frequencies of DWIR between younger and elderly patients who underwent successful recanalization with MT.
METHODS: The study retrospectively analyzed 177 consecutive patients who underwent successful recanalization with MT for anterior large vessel occlusion (LVO) at our hospital between April 2011 and September 2022. Patients were categorized into two age groups: <70 years and ≥70 years. MRI was performed before treatment and 24 hours after treatment. The DWI lesion volumes and DWIR frequencies were compared between the two groups.
RESULTS: The median age of the patients was 78 years and 19.8% were in the <70 years group. No significant differences were found between the groups in terms of occluded vessel sites and recanalization time. The baseline DWI lesion was significantly larger in the <70 years group (16.0 mL vs 4.0 mL, P<0.001). The frequency of DWIR did not significantly differ between the groups (65.7% vs 55.6%). DWI lesion volume significantly decreased after treatment in the <70 years group but showed no significant change in the ≥70 years group.
CONCLUSIONS: In patients who underwent successful recanalization after MT for anterior LVO, baseline DWI lesions were significantly larger in younger patients compared with elderly patients. Although more than half of the patients in both age groups experienced DWIR, a significant reduction in DWI lesion volume was only observed in younger patients.

BACKGROUND: Endovascular embolization is frequently used for vascular lesions of the head and neck. Newer agents may help to enhance visualization and improve treatment outcomes.
METHODS: The CLARIDAD clinical trial was a prospective, single center, first-in-man investigation of neurovascular embolization using the novel embolic agent ihtObtura for a broad indication, covering the need for a liquid embolic agent in head and neck procedures. The primary outcomes assessed were therapeutic efficacy to deliver ihtObtura to embolize the catheterized pedicle and associated angiographic vascularity, and subsequent loss of radiopacity. Safety endpoints included procedural adverse events, modified Rankin Scale (mRS) score, morbidity, and mortality. Radiologic and clinical follow-up evaluations were conducted at 30, 90, 180 days, and 1 year post-treatment.
RESULTS: 65 consecutive patients (mean age 37.8 years, 50.8% women) were treated over 129 sessions. A total of 42 brain arteriovenous malformations (AVMs; 90% grades III and IV), 8 dural arteriovenous fistulas (DAVFs), and 15 hypervascular tumors were treated with ihtObtura using an average of 3.9 mL per session and 7.7 mL per patient. We achieved therapeutic effectiveness in 99% of catheterizations. Radiopacity loss was complete after 74.3% of the sessions at 30 days, 95.6% at 90 days, and 100% at the 1 year follow-up. Serious adverse events (mRS score >2) occurred in two patients (3.1%) with previously ruptured high grade AVMs leading to one death and one permanent disabling morbidity.
CONCLUSIONS: The study showed that ihtObtura was a novel, safe, and effective liquid embolic agent for the treatment of AVMs, DAVFs, and hypervascular tumors. Its key property of significant radiopacity loss contributes to improve anatomical understanding, particularly in staged procedures, as well as reduction in post-procedural imaging artifact. There may be additional benefits of eliminating tantalum from the embolic mixture in terms of lesion penetration.

BACKGROUND: With transradial access (TRA) being more progressively used in neuroendovascular procedures, we compared TRA with transfemoral access (TFA) in middle meningeal artery embolization (MMAE) for chronic subdural hematoma (cSDH).
METHODS: Consecutive patients undergoing MMAE for cSDH at 14 North American centers (2018-23) were included. TRA and TFA groups were compared using propensity score matching (PSM) controlling for: age, sex, concurrent surgery, previous surgery, hematoma thickness and side, midline shift, and pretreatment antithrombotics. The primary outcome was access site and overall complications, and procedure duration; secondary endpoints were surgical rescue, radiographic improvement, and technical success and length of stay.
RESULTS: 872 patients (median age 73 years, 72.9% men) underwent 1070 MMAE procedures (54% TFA vs 46% TRA). Access site hematoma occurred in three TFA cases (0.5%; none required operative intervention) versus 0% in TRA (P=0.23), and radial-to-femoral conversion occurred in 1% of TRA cases. TRA was more used in right sided cSDH (58.4% vs 44.8%; P<0.001). Particle embolics were significantly higher in TFA while Onyx was higher in TRA (P<0.001). Following PSM, 150 matched pairs were generated. Particles were more utilized in the TFA group (53% vs 29.7%) and Onyx was more utilized in the TRA group (56.1% vs 31.5%) (P=0.001). Procedural duration was longer in the TRA group (median 68.5 min (IQR 43.1-95) vs 59 (42-84); P=0.038), and radiographic success was higher in the TFA group (87.3% vs 77.4%; P=0.036). No differences were noted in surgical rescue (8.4% vs 10.1%, P=0.35) or technical failures (2.4% vs 2%; P=0.67) between TFA and TRA. Sensitivity analysis in the standalone MMAE retained all associations but differences in procedural duration.
CONCLUSIONS: In this study, TRA offered comparable outcomes to TFA in MMAE for cSDH in terms of access related and overall complications, technical feasibility, and functional outcomes. Procedural duration was slightly longer in the TRA group, and radiographic success was higher in the TFA group, with no differences in surgical rescue rates.

We present the first reported case that describes the complete resolution of a meningioma following endovascular embolization. A man in his 70s who presented with gait abnormalities and recurrent falls was diagnosed with normal pressure hydrocephalus (NPH) and found to have a small incidental meningioma. Due to ventriculoperitoneal (VP) shunt placement for cerebrospinal fluid diversion, the patient developed a bilateral subdural hematoma (SDH) requiring evacuation and drain placement. The patient also underwent bilateral middle meningeal artery (MMA) embolization. During the embolization, the known right frontal meningioma was embolized as it was supplied by the right MMA. The patient remained neurologically stable after this procedure. His follow-up magnetic resonance imaging (MRI) 1 year and 2 years after the procedure demonstrated complete resolution of the meningioma.

BACKGROUND: Cerebral arteriovenous malformations (AVMs) are complex lesions that can cause hemorrhagic stroke and significant neurological disability. Adenosine induces cardiac standstill and hypotension, which are thought to be useful during cerebral AVM embolization. Herein, we conducted a systematic review and meta-analysis of the technique\'s safety.
METHODS: Following PRISMA guidelines, four databases were queried for studies describing the use of adenosine-assisted embolization of cerebral AVMs. Adenosine-related intraoperative complications, permanent neurological outcomes, morbidity, and mortality assessed the technique\'s safety. Single proportion analysis under a random-effects model was performed. Heterogeneity was assessed using I² statistics, and publication bias was evaluated through funnel plot analysis and Egger\'s regression test.
RESULTS: Ten studies were included, involving 79 patients (55.7% male) with 79 AVMs (54.4% unruptured and 70.9% Spetzler-Martin grade III-V) who underwent 123 embolizations (80.4% and 5.9% under transarterial and transvenous approaches, respectively) with n-butyl cyanoacrylate (80.4%), ethylene vinyl alcohol (14.4%), or both (5.2%). The incidence of transient adenosine-related intraoperative complications was 0% (95% CI 0% to 3%, I2=24%). Besides, the incidence of adenosine-related morbidity, mortality, and permanent outcomes was 0% (95% CI 0% to 3%, I2=0%). During follow-up, good functional outcomes were reported for 64 patients (81%).
CONCLUSIONS: Adenosine\'s effects on blood flow control can facilitate embolization and mitigate the risk of AVM rupture and embolic agent migration. Although current evidence stems from observational studies, the results of this meta-analysis suggest a safe drug profile due to minimal associated morbidity and mortality. Further research from larger randomized and controlled studies is warranted to attain a higher level of evidence.
UNASSIGNED: CRD42023494116.

BACKGROUND: Carotid web (CaW) is a risk factor for ischemic stroke, mainly in young patients with stroke of undetermined etiology. Its detection is challenging, especially among non-experienced physicians.
METHODS: We included patients with CaW from six international trials and registries of patients with acute ischemic stroke. Identification and manual segmentations of CaW were performed by three trained radiologists. We designed a two-stage segmentation strategy based on a convolutional neural network (CNN). At the first stage, the two carotid arteries were segmented using a U-shaped CNN. At the second stage, the segmentation of the CaW was first confined to the vicinity of the carotid arteries. Then, the carotid bifurcation region was localized by the proposed carotid bifurcation localization algorithm followed by another U-shaped CNN. A volume threshold based on the derived CaW manual segmentation statistics was then used to determine whether or not CaW was present.
RESULTS: We included 58 patients (median (IQR) age 59 (50-75) years, 60% women). The Dice similarity coefficient and 95th percentile Hausdorff distance between manually segmented CaW and the algorithm segmented CaW were 63.20±19.03% and 1.19±0.9 mm, respectively. Using a volume threshold of 5 mm3, binary classification detection metrics for CaW on a single artery were as follows: accuracy: 92.2% (95% CI 87.93% to 96.55%), precision: 94.83% (95% CI 88.68% to 100.00%), sensitivity: 90.16% (95% CI 82.16% to 96.97%), specificity: 94.55% (95% CI 88.0% to 100.0%), F1 measure: 0.9244 (95% CI 0.8679 to 0.9692), area under the curve: 0.9235 (95%CI 0.8726 to 0.9688).
CONCLUSIONS: The proposed two-stage method enables reliable segmentation and detection of CaW from head and neck CT angiography.

OBJECTIVE: To investigate associations between individual embolic protection device (EPD) use and respective center policy with periprocedural outcomes after carotid artery stenting (CAS).
METHODS: This analysis is based on the nationwide German statutory quality assurance database and was funded by Germany\'s Federal Joint Committee Innovation Fund (G-BA Innovationsfonds, 01VSF19016 ISAR-IQ). According to their policy towards EPD use, hospitals were categorized as routine EPD (>90%), selective EPD (10-90%), or sporadic EPD (<10%) centers. Primary study outcome was in-hospital stroke or death. Univariate and multivariate regression analyses were performed.
RESULTS: Overall, 19 302 patients who had undergone CAS between 2013 and 2016 were included. The highest in-hospital stroke or death rate was found in sporadic EPD centers, followed by selective and routine EPD centers (3.1% vs 2.9% vs 1.8%; P<0.001). Across the whole cohort, EPD use was associated with a lower in-hospital stroke or death rate (OR=0.60; 95% CI 0.50 to 0.72). In the multivariate regression analysis, EPD use was independently associated with a lower in-hospital stroke rate (aOR=0.66; 95% CI 0.46 to 0.94). Regarding center policy, routine EPD centers showed a significantly lower in-hospital mortality compared with sporadic EPD centers (aOR=0.44; 95% CI 0.22 to 0.88).
CONCLUSIONS: In a contemporary real-world cohort with low risk of selection bias, EPD use was associated with a lower in-hospital risk of stroke. A center policy of routine EPD use was associated with lower mortality. These data support routine use of EPD during CAS to enhance patient safety.

Many people with pain from osteoarthritis (OA) of the knee are either not ready for surgery or may never be surgical candidates. Genicular artery embolization (GAE) is a new proposed management for those with pain despite maximum medical management. It has historically been used to manage recurrent spontaneous haemarthrosis following total knee replacement, but newer studies are showing a positive effect in managing pre-arthroplasty knee OA. The goal of this review is to summarise current and relevant literature from searches of computerised databases and relevant journals, and analyse their results. Studies included show that GAE has promising outcomes in managing mild to moderate OA knee pain in those who have exhausted at least 3 months of conservative therapy. Most studies show improvements in VAS pain and PROM scores (including KOOS, and/or WOMAC). Minimal adverse effects have been associated in up to two years of follow up, the majority of which are self-resolving. The article précises a concise general procedural technique for performing GAE, as well as comparing and contrasting different embolic agents that may be utilised. GAE shows promising outcomes in management of mild to moderate OA knee pain. In the future, there will need to be higher volume studies to determine effectiveness, suitable candidates, and other potential adverse effects.

BACKGROUND: This study quantifies the impact of middle meningeal artery embolization (MMAE) for subdural hematomas (SDHs) by estimating a target population.
METHODS: A population-based study at a tertiary hospital, the main SDH facility for a four-county population, used primary ICD-10 codes over 3 years to collate SDH hospitalizations. Clinical and imaging data confirmed traumatic versus non-traumatic and acute versus non-acute (mixed or chronic) SDH. The MMAE-eligible population included patients with non-traumatic, non-acute SDH aged ≥18 years plus patients with \'traumatic\' but non-acute SDH aged ≥60 years presenting with a fall. This was contrasted with the rate of large vessel strokes in the same population.
RESULTS: 1279 hospitalizations with a primary ICD-10 SDH diagnosis were identified, with 389 from the study population. Excluding repeat admissions, 350 patients were analyzed, 233 (67%) traumatic, and 117 (33%) non-traumatic SDH. Regarding etiology, \'fall ≥60 years\' was the most common category in the entire cohort (n=156; 45% (95% CI 39% to 50%)). The SDH rate was 52/100 000 persons/year (95% CI 47 to 57). The rate of all non-traumatic, non-acute SDH in patients aged ≥18 years was 17/100 000 persons/year (95% CI 15 to 20), combining with \'traumatic\' but non-acute fall-related SDH in patients aged ≥60 years yielded 41/100 000 persons/year (95% CI 36 to 47). This demographic may represent an MMAE-eligible population, exceeding large vessel stroke rates (31/100 000 persons/year) in the same population, estimating 139 387 potential MMAE cases/year (95% CI 121 517 to 158 168) in the USA.
CONCLUSIONS: MMAE could transform non-acute SDH management, especially in the elderly, potentially surpassing the impact of large vessel stroke. Clinical trials are essential for validation of its efficacy and safety compared with standard management.

BACKGROUND: Acute embolic ischemic stroke poses a significant healthcare challenge. Histological clot features\' variability among patients with acute ischemic stroke treated by mechanical thrombectomy has potential implications for determining treatment and etiology. This study investigated the clot histological feature differences among patients who experienced cardioembolic stroke and embolic stroke of undetermined source with different left atrial appendage (LAA) morphologies.
METHODS: We conducted a prospective observational study involving 79 patients with acute embolic ischemic stroke undergoing mechanical thrombectomy. Computed tomography angiography images were used to classify LAA morphologies. An artificial intelligence algorithm assessed the clot fibrin and red blood cell contents.
RESULTS: Patients with chicken-wing LAA morphology exhibited lower mean clot fibrin proportions than did those with non-chicken-wing morphology (p < 0.001). Linear regression analysis showed that chicken-wing LAA was significantly associated with a lower clot fibrin proportion (estimate, -0.177; 95% CI [-0.259, -0.096]; p < 0.001). The successful recanalization rate and first-pass effect between the groups did not differ significantly.
CONCLUSIONS: The chicken-wing LAA morphological type is associated with lower clot fibrin contents, suggesting potentially different embolism mechanisms or diverse embolic sources, compared with the non-chicken-wing LAA types. Further studies are required to investigate this association.