Bain, Mark

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.

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.

Abstract Acute carotid terminus occlusion (CTO) is responsible for up to 5% of acute ischemic strokes secondary to emergent large vessel occlusion (ELVO) and up to 20% of acute internal carotid artery (ICA) occlusions. 1 The term “CTO” has also been used to describe occlusions in the supra-clinoid segment or at the bifurcation of the ICA. Compared to other ELVOs, patients with CTO present with higher stroke severity and larger infarct volume, likely to be a result of disruption of direct Circle of Willis collaterals across the anterior communicating artery (AComA) and posterior communicating artery (PComA). 2,3 Similary, CTO is usually associated with worse prognosis compared to other ELVOs in general. With regard to response to treatment, previous studies have reported significantly lower recanalization rates with intravenous alteplase with CTO compared to M1 segment occlusion. With regard to the safety and efficacy of mechanical thrombectomy, prior reports provide conflicting results with some reporting lower successful recanalization rates with CTO compared to M1 occlusion, and others reporting similar results. In our experience, we have found that successful recanalization of CTO can be achieved with a similar approach to M1 occlusions utilizing a direct aspiration first pass technique (ADAPT). 3,4 Herein, we present a case of CTO for which we performed mechanical thrombectomy using ADAPT. This procedure was an emergent standard of care procedure for which a consent was not required and so not obtained.

Abstract Transfemoral access has long been the main access site for cerebral angiography and neurointerventional procedures. Radial access is accepted as an alternative to the traditional transfemoral approach. Ulnar access may be undertaken if the radial artery is occluded or small caliber, or when radial artery preservation is needed. The safety and feasibility of ulnar access for neuroangiographic procedures has been demonstrated. 1-3 In this operative video, we demonstrate ulnar artery access in a patient in whom radial artery preservation was desired. We further elaborate on the technical nuances of this access. This nontraditional access site offers the same advantages as radial access, avoiding the need to switch to femoral artery access. A preoperative Allen's test is not necessary. Ultrasound imaging is used to aid in the identification and successful puncture of the ulnar artery. A medial to lateral approach for ulnar artery puncture is advised to avoid injury to the ulnar nerve. Careful application of wrist closure bands avoids hematoma accumulation. The patient gave informed consent for the procedure and video recording. Institutional review board approval was deemed unnecessary. Video. © University at Buffalo, May 2021. Used with permission.

Abstract Basilar artery occlusions (BAOs) are devastating ischemic strokes that account for 1% of all strokes with high morbidity and mortality; however, neuroendovascular techniques such as ADAPT have recently revolutionized the clinical outcomes of these patients. 1-3 Common underlying pathology in patients with BAO include intracranial atherosclerotic disease (ICAD) as well as thromboembolic origin. 4 Basilar artery ICAD in a setting of acute stroke portends a poor prognosis and post-thrombectomy residual critical flow limiting stenosis treatment options, including balloon angioplasty with or without stent placement. 5-7 We present a video illustration of neuroendovascular technique and challenges encountered when managing this pathology. Image at 5:42 reprinted with permission from Alawieh et al, Lessons learned over more than 500 stroke thrombectomies using ADAPT with increasing aspiration catheter size, Neurosurgery , 86(1), 2020, pp. 61-70, with permission from the Congress of Neurological Surgeons. 1

Abstract In-stent stenosis has a reported prevalence of 14% to 19% at 1-yr follow-up after carotid stenting and is associated with an increased risk of acute ischemic stroke. 1,2 Risk factors include female sex, diabetes, and dyslipidemia. Cutting balloon angioplasty is a safe and effective treatment modality for the treatment of carotid in-stent stenosis, and alternative treatment options include observation with medical management and placement of another stent. 3,4 The authors present the case of a 61-yr-old man with carotid in-stent restenosis and progressive worsening on serial imaging with ultrasound. The patient had a history of carotid stenting for symptomatic stenosis 6 mo prior and was maintained on aspirin and clopidogrel. In light of the progressive worsening, the in-stent stenosis was confirmed on computed tomography (CT) angiogram. The options were discussed with the patient and he consented for treatment with cutting balloon angioplasty. Final angiogram showed improvement of the luminal diameter with a residual stenosis of 15%. The patient tolerated the procedure well and was discharged home on postoperative day 1. Follow-up ultrasound demonstrated moderate improvement in peak systolic velocities, and the plan is to continue observation with a clinical follow-up and repeat carotid Dopplers at 3 mo.

Abstract Embolic protection devices (EPDs) have become a standard of care during internal carotid artery revascularization. 1,2 This video is about a 57-yr-old-male who presented with a wake-up stroke with a left hemispheric syndrome. Head computed tomography angiography (CTA) revealed tandem occlusions of the proximal left internal carotid artery (ICA) and of the distal left middle cerebral artery (MCA) with an ASPECT (Alberta Stroke Program Early CT Score) score of 6. The patient underwent a cerebral angiogram and was treated with balloon angioplasty with a distal EPD and mechanical thrombectomy. The EPD became occluded with thrombus from the ICA and was retrieved through a 6-Fr Sofia (MicroVention) under continuous aspiration. Successful revascularization of the proximal ICA and distal MCA was achieved. No procedure-related complications occurred, and the patient's neurological exam improved. Tandem occlusions can occur in up to 15% of strokes. The optimal treatment can be controversial, but mechanical thrombectomy and ICA revascularization with a distal EPD appear to be safe and effective in selected patients. 3 Consent was obtained for the procedure and for the video production.

Abstract Intracranial atherosclerotic disease (ICAD) is a common cause of stroke. Antiplatelet therapy is the mainstay for symptomatic ICAD treatment. Endovascular management with submaximal angioplasty and/or intracranial stenting is reserved for patients with repeated ischemic events despite optimal medical therapy. We demonstrate intracranial angioplasty and stenting technique, technique indications, and sizing of stent and target vessel diameter. Stenting and angioplasty have been described in the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis and Wingspan Stent System Post Market Surveillance trials. 1,2 Submaximal angioplasty has also been described. 3 This patient, who had been on dual antiplatelet therapy for several months, initially presented with occlusion of the left middle cerebral artery M2 inferior division and underwent mechanical thrombectomy with successful reperfusion. Postoperatively, the patient's symptoms did not improve. Medical management was optimized with heparin infusion. However, repeat stroke study demonstrated M2 inferior division reocclusion. A decision was made to proceed with intracranial angioplasty and stenting. P2Y12 levels were therapeutic. Under moderate conscious sedation, submaximal angioplasty of up to 80% of the normal M2 caliber was attempted. However, we observed persistent high-grade stenosis of the M2 inferior division. The major risk of crossing the lesion for angioplasty is vessel perforation. To safely perform this maneuver, we used a J-configured Synchro-2 microwire (Stryker). Because of the patient's recent thrombectomy, we also had prior tactile feedback about how much resistance was encountered while crossing the occlusion. We then deployed a balloon-mounted intracranial stent for optimal radial force across the stenotic area to restore perfusion. Postoperative computed tomography perfusion showed resolution of the previously noticed perfusion deficit. The patient gave informed consent for the procedures and video recording. Institutional review board approval was deemed unnecessary. Video. ©University at Buffalo Neurosurgery, September 2020. With permission.