Flow diversion for intracranial aneurysms emerged as an efficacious and durable treatment option over the last two decades. In a paradigm shift from intrasaccular aneurysm embolization to parent vessel remodeling as the mechanism of action, the proliferation of flow-diverting devices has enabled the treatment of many aneurysms previously considered untreatable. In this review, we review the history and development of flow diverters, highlight the pivotal clinical trials leading to their regulatory approval, review current devices including endoluminal and intrasaccular flow diverters, and discuss current and expanding indications for their use. Areas of clinical equipoise, including ruptured aneurysms and wide-neck bifurcation aneurysms, are summarized with a focus on flow diverters for these pathologies. Finally, we discuss future directions in flow diversion technology including bioresorbable flow diverters, transcriptomics and radiogenomics, and machine learning and artificial intelligence.

Background: Recent trials have furthered uncertainty regarding the endovascular benefit for medium vessel occlusions (MeVO). Stent retrievers (SR) were employed in the first attempt in most interventional arm participants. We sought to compare outcomes in acute MCA M2 occlusions between frontline aspiration and SR, and to delineate procedural and anatomical covariates associated with differential treatment effect. Methods: Retrospective analysis of a multicenter stroke thrombectomy cohort identified cases of MT for M2 occlusions. Unmatched and propensity score-matched (PSM) cohorts were generated comparing frontline aspiration to standalone and combined SR. The primary outcome was functional independence (mRS 0–2) at 90 days. Recanalization, symptomatic intracranial hemorrhage (sICH), mortality, and the effect of M2 laterality, division occlusion and procedure time were assessed. Results: About 1734 patients with M2 occlusions underwent either frontline aspiration (n = 711) or SR/combined (n = 958) thrombectomy between 2013 and 2024. PSM analysis favored aspiration for functional independence (49.9% vs 44.0%, OR 1.27 (1.03–1.57)), complete recanalization (61.2% vs 48.7%, OR 1.66 (1.34–2.05)), complete first pass effect (35.0% vs 27.6%, OR 1.42 (1.13–1.78)), and sICH (3.5% vs 6.2%, OR 0.55 (0.33–0.91)), with no difference in mortality. Frontline aspiration had significantly shorter procedural times (median 28 [IQR 15–49.5] vs 51 [IQR 35–78] minutes; p < 0.001). For every minute increase in procedure time, the probability of functional independence decreased significantly (p < 0.001) less with frontline aspiration (0.35%) compared to SR/combined (1.61%). Conclusion: Frontline aspiration for M2 occlusions resulted in better clinical and angiographic outcomes compared to SRs. Future trials for MeVO with a focus on contact aspiration thrombectomy may succeed where recent trials have failed.

BACKGROUND: Chondromyxoid fibroma (CMF) is a rare tumor usually found in the epiphysis and metaphysis of long bones. In the absence of effective nonsurgical treatment modalities, radical tumor resection is recommended. Spinal CMFs present a unique surgical challenge making total tumor resection often impossible. Little is documented about the long-term prognosis of spinal CMFs after subtotal resection, but inferring from outcomes of extremity CMF surgery, tumor recurrence is to be expected after incomplete resection. OBSERVATIONS: The authors present a 6-year follow-up case of an incompletely resected large lumbar CMF involving the L5 vertebra. This case appears to be the largest documented spinal CMF with the longest follow-up period after subtotal resection. Despite a residual tumor in the proximity of the inferior L5 endplate on immediate postoperative imaging, the patient has remained asymptomatic and without soft tissue tumor progression or recurrence for more than 6 years (77 months). LESSONS: The long-term outcome of this case demonstrates that total tumor resection may not be necessary for long-term disease control. This finding is in agreement with 14 previously reported lumbar CMFs, with only 1 documented recurrence at 60 months. https://thejns.org/doi/abs/10.3171/CASE25350

Introduction Intravenous (IV) tenecteplase (TNK) has emerged as an alternative to IV alteplase (tPA) in the treatment of acute ischemic stroke. Prior studies have shown non-inferiority with better reperfusion and functional outcomes after mechanical thrombectomy (MT) with TNK versus tPA. Methods Prospective thrombolytic data from a multi-center US stroke consortium was collected over a 30-month period between 2019 and 2022. National Institutes of Health stroke scale (NIHSS) at presentation, site of vessel occlusion, post-MT Thrombolysis in Cerebral Infarction (TICI) score, discharge modified Rankin Scale (mRS), discharge ambulatory status, and post-MT intracranial hemorrhage (ICH) were analyzed using non-parametric tests. ICH included parenchymal hematoma Type 2, intraventricular hemorrhage, subarachnoid hemorrhage, remote site of intraparenchymal hemorrhage outside the area of infarction, and other positive findings. Results A total of 168 patients were included for analysis, of which a third were Hispanic. With exception of ethnicity, there were no differences in patient demographics or stroke location/severity between groups (table 1). Clinical and radiographic outcome variables were comparable between groups (table 2). Conclusion In this prospective, multi-center stroke consortium study, IV TNK in comparison to tPA prior to MT for ischemic stroke resulted in non-inferior outcomes related to angiographic reperfusion and functional status at discharge. These findings compliment the current literature and include a large Hispanic US cohort. Further analysis will include expansion of contributing centers and use of propensity scoring. Disclosures M. Gaub: None. D. Ramaswamy: None. A. Cardentey: None. S. Bandela: None. G. Gealogo: None. J. Mascitelli: None. F. Al Saiegh: None. L. Birnbaum: 2; C; Rapid AI, Imperative Care.