Wakhloo, Ajay K.

Background The middle meningeal artery (MMA) has emerged as an endovascular route for treating chronic subdural hematoma (CSDH), meningioma, and refractory headaches. The third ARISE roundtable convened experts from neurology, neurosurgery, neuroradiology, industry, and regulatory agencies to develop consensus guidance on current evidence for MMA-based therapies Methods Over 50 experts participated in a multi-stakeholder discussion. Evidence from randomized and observational studies, early-phase interventional series, and preclinical work was reviewed. Breakout groups focused on four domains: (1) MMA embolization (MMAE) for CSDH, (2) preoperative embolization of meningiomas, (3) MMA-targeted therapies for headache, and (4) transvascular access for endovascular drainage of subdural hematomas. Consensus recommendations were developed by a writing committee Results Randomized trials support MMAE as an adjunct to surgery or medical management for selected patients with non-acute, symptomatic CSDH to reduce recurrence, progression, and reoperation. Evidence remains insufficient to support MMAE for acute or asymptomatic subdural hematomas. For meningioma, observational data suggest that preoperative embolization in experienced centers can reduce blood loss and operative time and may delay recurrence in large, hypervascular tumors with predominant dural or external carotid supply; primary embolization and intra-arterial oncologic therapies remain investigational. Early series of MMA-directed lidocaine infusion for refractory migraine, status migrainosus, and post-subarachnoid hemorrhage headache show short-term benefit, highlighting the need for controlled trials. Preclinical and first-in-human studies of combined MMAE and transvascular drainage for CSDH demonstrate high technical success, rapid radiographic and clinical improvement, and no early recurrences Conclusion The MMA represents a vascular pathway for an expanding spectrum of neurointerventional therapies.

BACKGROUND AND OBJECTIVES: The prospective single-arm nonrandomized SCENT (Surpass Intracranial Aneurysm Embolization System Pivotal) trial on flow diverter treatment of large and giant intracranial aneurysms (IA) was analyzed for patients' age and IA characteristics affecting stroke and occlusion rates over 5 years (Trial registration NCT01716117). METHODS: Impact on major ipsilateral stroke and IA occlusion was studied by stratifying age as 65 years and younger vs older than 65. Kaplan–Meier estimates of time to both endpoints, stratified by age, were created. Univariate predictors of time-to-stroke were analyzed using univariable proportional hazards regression models. Limited bivariable modeling was also attempted. RESULTS: Of 180 patients with large or giant IA enrolled, 119 were 65 years and younger, whereas 61 were older than 65 years. The 3-year risk of stroke for the older than 65 years group (19.7%) was more than double that of the 65 years and younger group (9.2%), P = .047. No new strokes were reported between 3 and 5 years. Four patients (2.2%) experienced aneurysm rupture within the first week post-treatment, 3 being 65 years and younger and the fourth older than 65 (>.99). Complete IA occlusion within age strata at 1 year was: older than 65 60% (33/55), 65 years and younger 79.1% (87/110), P = .009, 3 years: older than 65 67.6% (25/37), 65 years and younger 82.5% (66/80), P = .071, and 5 years: older than 65 85.7% (18/21), 65 years and younger 91.8% (56/61), P = .417. CONCLUSION: Age older than 65 was associated with an increased risk of stroke and predictive of incomplete healing and increased time to healing.

Introduction/Purpose The multicenter, prospective, single‐arm, controlled, non‐randomized SCENT trial on flow diverter (FD) treatment for intracranial aneurysms (IA) was analyzed for patients’ age and IA characteristics impacting stroke and occlusion rates over 5 years. Materials and Methods Impact on major ipsilateral stroke and IA occlusion was studied by stratifying age as </= 65 years versus >65 years. Twice as many subjects treated were </= 65 years old (n=119/180). Product‐limit (Kaplan‐Meier) estimates of time to both endpoints, stratified by age group, were created. Univariate predictors of time to stroke were identified by including candidate variables in univariable proportional hazards regression models. Those variables found to be significant (p<0.10) at the univariate level were entered into a multivariable survival model to identify independent predictors. The stepwise selection produced a final reduced model with a significance level to both enter and stay set at 0.05. Results When parent artery stenosis and IA size were entered into a multiple‐stepwise survival model, only stenosis remained as an independently significant predictor of time to stroke. At 3‐year follow‐up, there were a total of 23 strokes (12.8%), with 11 (47.8%) occurring in subjects </= 65 years; there was a greater risk for seniors (HR1.96, 95% CI 0.83‐4.78, p=.122). Four patients (4/180; 2.2%) experienced aneurysm ruptured within the first week post‐treatment, with 3 being </= 65 and the fourth aged 66 years. No new strokes were reported between 3 and 5 years. Complete IA occlusion rates for seniors were 60.0% (33/55), 67.6% (25/37), and 85.7% (18/21) at 12, 36, and 60 months, respectively, as compared to 79.1% (87/110), 82.5% (66/80), and 91.8% (56/61) for younger subjects. The time to complete IA occlusion was shorter in younger patients (HR1.53, 95% CI 1.07‐2.19, p=.020). Five subjects (2.8%) underwent retreatment, 2 in 60‐year‐old patients, and one each aged 64, 70, and 75. Conclusion Stroke, early rupture risk, and aneurysm occlusion in patients treated with FD are related to age and pre‐existing parent artery stenosis, IA size, and location. With demographic shifts, future treatments need to focus on expedited and improved healing.

Brain arteriovenous malformations (bAVMs) are complex, and rare arteriovenous shunts that present with a wide range of signs and symptoms, with intracerebral hemorrhage being the most severe. Despite prior societal position statements, there is no consensus on the management of these lesions. ARISE (Aneurysm/bAVM/cSDH Roundtable Discussion With Industry and Stroke Experts) was convened to discuss evidence-based approaches and enhance our understanding of these complex lesions. ARISE identified the need to develop scales to predict the risk of rupture of bAVMs, and the use of common data elements to perform prospective registries and clinical studies. Additionally, the group underscored the need for comprehensive patient management with specialized centers with expertise in cranial and spinal microsurgery, neurological endovascular surgery, and stereotactic radiosurgery. The collection of prospective multicenter data and gross specimens was deemed essential for improving bAVM characterization, genetic evaluation, and phenotyping. Finally, bAVMs should be managed within a multidisciplinary framework, with clinical studies and research conducted collaboratively across multiple centers, harnessing the collective expertise and centralization of resources.

ARISE (Aneurysm/AVM/cSDH Roundtable Discussion With Industry and Stroke Experts) organized a one-and-a-half day meeting and workshop and brought together representatives from academia, industry, and government to discuss the most promising approaches to improve outcomes for patients with chronic subdural hematoma (cSDH). The emerging role of middle meningeal artery embolization in clinical practice and the design of current and potential future trials were the primary focuses of discussion. Existing evidence for imaging, indications, agents, and techniques was reviewed, and areas of priority for study and key questions surrounding the development of new and existing treatments for cSDH were identified. Multiple randomized, controlled trials have met their primary efficacy end points, providing high-level evidence that middle meningeal artery embolization is a potent adjunctive therapy to the standard (surgical and nonsurgical) management of neurologically stable cSDH patients in terms of reducing rates of disease recurrence. Pooled data analyses following the formal conclusion and publication of these trials will form a robust foundation upon which guidelines can be strengthened for cSDH treatment modalities and optimal patient selection, as well as delineate future lines of investigation.