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BackgroundFew studies have explored the association between stroke thrombectomy (ST) volume and hospital accreditation with clinical outcomes.ObjectiveTo assess the association of ST case volume and accreditation status with in-hospital mortality and home discharge disposition using the national Medicare Provider Analysis and Review (MEDPAR) database.MethodsRates of hospital mortality, home discharge disposition, and hospital stay were compared between accredited and non-accredited hospitals using 2017–2018 MEDPAR data. The association of annual ST case volume with mortality and home disposition was determined using Pearson’s correlation. Median rate of mortality and number of ST cases at hospitals within the central quartiles were estimated.ResultsA total of 29 355 cases were performed over 2 years at 847 US centers. Of these, 354 were accredited. There were no significant differences between accredited and non-accredited centers for hospital mortality (14.8% vs 14.5%, p=0.34) and home discharge (12.1% vs 12.0%, p=0.78). A significant positive correlation was observed between thrombectomy volume and home discharge (r=0.88; 95% CI 0.58 to 0.97, p=0.001). A significant negative relationship was found between thrombectomy volume and mortality (r=−0.86; 95% CI −0.97 to −0.49, p=0.002). Within the central quartiles, the median number of ST cases at hospitals with mortality was 24/year, and the median number of ST cases at hospitals with home discharge rate was 23/year.ConclusionA higher volume of ST cases was associated with lower mortality and higher home discharge rate. No significant differences in mortality and discharge disposition were found between accredited and non-accredited hospitals.

BackgroundThere is conflicting evidence on the utility of intravenous (IV) alteplase in patients with emergent large vessel occlusion (ELVO) treated with mechanical thrombectomy (MT).MethodsThis was a post hoc analysis of the COMPASS: a trial of aspiration thrombectomy versus stent retriever thrombectomy as first-line approach for large vessel occlusion. We compared clinical, procedural and angiographic outcomes of patients with and without prior IV alteplase administration.ResultsIn the COMPASS trial, 235 patients had presented to the hospital within the first 4 hours of stroke symptom onset and were eligible for analysis. On univariate analysis, administration of IV alteplase prior to MT was found to be significantly associated with favorable outcomes (modified Rankin scale (mRS) 0–2 at 3 months; 55.6% vs 40.0% in the MT-only group, P=0.037). However, on multivariate analysis, only baseline (pre-stroke) mRS, admission National Institutes of Health Stroke Scale (NIHSS) score and age were identified as independent predictors of favorable outcomes at 3 months. We found higher final thrombolysis in cerebral infarction (TICI) 2b/3 rates in patients without the use of alteplase prior to the aspiration first approach (100.0% vs 87.9% in IV altepase +aspiration first MT, P=0.03). In the stent retriever first group, final TICI 2b/3 rates were identical in patients with and without IV alteplase administration (87.5% and 87.5%, P=1.0).ConclusionsPrior administration of IV alteplase may adversely affect the efficacy of aspiration, but does not seem to influence the stent retriever first approach to MT in patients with anterior circulation ELVO.

Background Mechanical thrombectomy (MT) is the standard of care for the treatment of proximal anterior circulation large vessel occlusions. However, little is known about its efficacy and safety in the treatment of distal intracranial occlusions. Methods This is a multicenter retrospective study of patients treated with MT at 15 comprehensive centers between January 2015 and December 2018. The study cohort was divided into 2 groups based on the location of occlusion (proximal vs. distal). Distal occlusion was defined as occlusion of M3 segment of the middle cerebral artery, any segment of the anterior cerebral artery, or any segment of the posterior cerebral artery. Only isolated distal occlusion was included. Good outcome was defined as 90-day modified Rankin scale score 0–2. Results A total of 4710 patients were included in this study, of whom 189 (4%) had MT for distal occlusions. Compared with the proximal occlusion group, distal occlusion group had a higher rate of good outcome (45% vs. 36%; P = 0.03) and a lower rate of successful reperfusion (78% vs. 84%; P = 0.04). However, the differences did not retain significance in adjusted models. Otherwise there was no difference in the rate of hemorrhagic complications, mortality, or procedure-related complications between the 2 groups. Successful reperfusion, age, and admission stroke severity emerged as predictors of good functional outcome in the distal occlusion group. Conclusions Thrombectomies of distal vessels achieve high rate of successful reperfusion with similar safety profile to those in more proximal locations.

Background Accurate aneurysm measurements are important for selecting the WEB device. The objective was to validate a cloud-based platform, SurgicalPreview (SP) against manual measurements for aneurysm analysis. Methods Two sets of measurements each for SP and manual methods were obtained for 40 aneurysms. Reliability and agreement were assessed with intra-class correlation coefficient (ICC) and Bland-Altman plots respectively. Kappa coefficient was used to assess agreement for predicting WEB size. Results There was good reliability for repeat SP measurements: aneurysm diameter (ICC-1, 95%CI 0.98–1), height (ICC-1, 95%CI 0.99–1) and neck diameter (ICC-0.96, 95%CI 0.93–0.98). There was good reliability for the two manual diameter (ICC-0.97, 95%CI 0.9–0.97) and height (ICC-0.93, 95%CI 0.87–0.96) measurements and moderate for neck diameter (ICC-0.76, 95%CI 0.54–0.87). There was greater agreement for SP versus manual repeat measurements on Bland-Altman plots. Reliability between the SP and manual methods was good for aneurysm diameter (ICC-0.98, 95%CI 0.95–1) and height (ICC-0.96, 95%CI-0.93–0.98) and moderate for neck. (ICC-0.6, 95%CI -0.22–0.87). The Bland-Altman plots confirmed better agreement between the two methods for the aneurysm diameter and height than the neck. There was strong agreement between the methods for predicting the WEB diameter (Kappa-0.84, 95%CI 0.71–0.97) and moderate for predicting WEB height (Kappa-0.66, 95%CI 0.43–0.89). There was moderate agreement for predicted versus deployed WEB diameter: SP (Kappa-0.56, 95%CI 0.38–0.74), Manual (Kappa-0.53, 95%CI 0.34–0.71). Conclusion The SurgicalPreview® had greater agreement for repeat measurements. There was good reliability between the two methods for predicting WEB diameter and height and moderate agreement between predicted versus deployed WEB diameter.

Intra-aortic CT Angiography (IA-CTA) is a relatively new technique that shows promise in efficient diagnosis and evaluation of the angioarchitecture of spinal dural arteriovenous fistulae(sdAVF). The authors document the first reported use of a 4D-CT and C-arm fluoroscope in a hybrid interventional suite to evaluate a sdAVF. Time resolved IA-CTA is clinically feasible in the evaluation of sdAVF, has higher temporal resolution as compared to standard IA-CTA and reduced contrast load, radiation dose and potential for procedural complications as compared to standard spinal angiography.

OBJECTIVE Although younger adults have been shown to have better functional outcomes after mechanical thrombectomy (MT) for acute ischemic stroke (AIS), the significance of this relationship in the adolescent and young adult (AYA) population is not well defined given its undefined rarity. Correspondingly, the goal of this study was to determine the prognostic significance of age in this specific demographic following MT for large-vessel occlusions. METHODS A prospectively maintained international multi-institutional database, STAR (Stroke Thrombectomy and Aneurysm Registry), was reviewed for all patients aged 12–18 (adolescent) and 19–25 (young adult) years. Parameters were compared using chi-square and t-test analyses, and associations were interrogated using regression analyses. RESULTS Of 7192 patients in the registry, 41 (0.6%) satisfied all criteria, with a mean age of 19.7 ± 3.3 years. The majority were male (59%) and young adults (61%) versus adolescents (39%). The median prestroke modified Rankin Scale (mRS) score was 0 (range 0–2). Strokes were most common in the anterior circulation (88%), with the middle cerebral artery being the most common vessel (59%). The mean onset-to–groin puncture and groin puncture–to-reperfusion times were 327 ± 229 and 52 ± 42 minutes, respectively. The mean number of passes was 2.2 ± 1.2, with 61% of the cohort achieving successful reperfusion. There were only 3 (7%) cases of reocclusion. The median mRS score at 90 days was 2 (range 0–6). Between the adolescent and young adult subgroups, the median mRS score at last follow-up was statistically lower in the adolescent subgroup (1 vs 2, p = 0.03), and older age was significantly associated with a higher mRS at 90 days (coefficient 0.33, p < 0.01). CONCLUSIONS Although rare, MT for AIS in the AYA demographic is both safe and effective. Even within this relatively young demographic, age remains significantly associated with improved functional outcomes. The implication of age-dependent stroke outcomes after MT within the AYA demographic needs greater validation to develop effective age-specific protocols for long-term care across both pediatric and adult centers.

BACKGROUND AND PURPOSE: Physician training and onsite proctoring are critical for safely introducing new biomedical devices, a process that has been disrupted by the pandemic. A teleproctoring concept using optical see-through head-mounted displays with a proctor's ability to see and, more important, virtually interact in the operator's visual field is presented. MATERIALS AND METHODS: Test conditions were created for simulated proctoring using a bifurcation aneurysm flow model for WEB device deployment. The operator in the angiography suite wore a Magic Leap-1 optical see-through head-mounted display to livestream his or her FOV to a proctor's computer in an adjacent building. A Web-based application (Spatial) was used for the proctor to virtually interact in the operator's visual space. Tested elements included the quality of the livestream, communication, and the proctor's ability to interact in the operator's environment using mixed reality. A hotspot and a Wi-Fi-based network were tested. RESULTS: The operator successfully livestreamed the angiography room environment and his FOV of the monitor to the remotely located proctor. The proctor communicated and guided the operator through the procedure over the optical see-through head-mounted displays, a process that was repeated several times. The proctor used mixed reality and virtual space sharing to successfully project images, annotations, and data in the operator's FOV for highlighting any device or procedural aspects. The livestream latency was 0.71 (SD, 0.03) seconds for Wi-Fi and 0.86 (SD, 0.3) seconds for the hotspot (P = .02). The livestream quality was subjectively better over the Wi-Fi. CONCLUSIONS: New technologies using head-mounted displays and virtual space sharing could offer solutions applicable to remote proctoring in the neurointerventional space.

BackgroundThe benefit of complete reperfusion (modified Thrombolysis in Cerebral Infarction (mTICI) 3) over near-complete reperfusion (≥90%, mTICI 2c) remains unclear. The goal of this study is to compare clinical outcomes between mechanical thrombectomy (MT)-treated stroke patients with mTICI 2c versus 3.MethodsThis is a retrospective study from the Stroke Thrombectomy and Aneurysm Registry (STAR) comprising 33 centers. Adults with anterior circulation arterial vessel occlusion who underwent MT yielding mTICI 2c or mTICI 3 reperfusion were included. Patients were categorized based on reperfusion grade achieved. Primary outcome was modified Rankin Scale (mRS) 0–2 at 90 days. Secondary outcomes were mRS scores at discharge and 90 days, National Institutes of Health Stroke Scale score at discharge, procedure-related complications, and symptomatic intracerebral hemorrhage.ResultsThe unmatched mTICI 2c and mTICI 3 cohorts comprised 519 and 1923 patients, respectively. There was no difference in primary (42.4% vs 45.1%; p=0.264) or secondary outcomes between the unmatched cohorts. Reperfusion status (mTICI 2c vs 3) was also not predictive of the primary outcome in non-imputed and imputed multivariable models. The matched cohorts each comprised 191 patients. Primary (39.8% vs 47.6%; p=0.122) and secondary outcomes were also similar between the matched cohorts, except the 90-day mRS which was lower in the matched mTICI 3 cohort (p=0.049). There were increased odds of the primary outcome with mTICI 3 in patients with baseline mRS ≥2 (36% vs 7.7%; p=0.011; pinteraction=0.014) and a history of stroke (42.3% vs 15.4%; p=0.027; pinteraction=0.041).ConclusionsComplete and near-complete reperfusion after MT appear to confer comparable outcomes in patients with acute stroke.

BackgroundThe Woven EndoBridge (WEB) device is approved in the USA for treatment of unruptured wide-neck bifurcation aneurysms. However, the safety and effectiveness of the WEB device in the treatment of ruptured intracranial aneurysms is not clear. We aim to evaluate the perioperative safety and effectiveness of the WEB device in patients with ruptured intracranial aneurysms.MethodsThis retrospective study, conducted at eight centers in the USA, included patients with ruptured intracranial aneurysms treated with the WEB device in the setting of subarachnoid hemorrhage (SAH). Safety outcomes included intraoperative complications such as vessel perforation, thromboembolic events, and postoperative hemorrhagic or thromboembolic complications based on radiologic imaging. The primary effectiveness outcome was adequate (complete and neck remnant) aneurysm occlusion, according to the Raymond–Roy classification.ResultsA total of 91 patients with 94 ruptured intracranial aneurysms were included (mean age 57.7±15.2 years; 68.1% women; 82.9% wide-necked). Aneurysms were located in the anterior communicating artery (42/94, 44.6%), middle cerebral artery (16/94, 17%), and basilar artery (15/94, 16%). Adequate occlusion was achieved in 48.8% (41/84) and 80.0% (40/50) at discharge and last follow-up (mean of 3.4 months), respectively. At discharge, procedural-related morbidity was 3.3% (3/91) and there was no procedure-related mortality. No re-rupture or delayed aneurysm rupture was observed.ConclusionsThis study demonstrates the perioperative safety and effectiveness of the WEB device for the treatment of patients with ruptured intracranial aneurysms in the setting of SAH, with low periprocedural morbidity and mortality. Long-term follow-up is warranted.

BackgroundMechanical thrombectomy (MT) is the standard-of-care treatment for stroke patients with emergent large vessel occlusions. Despite this, little is known about physician decision making regarding MT and prognostic accuracy.MethodsA prospective multicenter cohort study of patients undergoing MT was performed at 11 comprehensive stroke centers. The attending neurointerventionalist completed a preprocedure survey prior to arterial access and identified key decision factors and the most likely radiographic and clinical outcome at 90 days. Post hoc review was subsequently performed to document hospital course and outcome.Results299 patients were enrolled. Good clinical outcome (modified Rankin Scale (mRS) score of 0–2) was obtained in 38% of patients. The most frequently identified factors influencing the decision to proceed with thrombectomy were site of occlusion (81%), National Institutes of Health Stroke Scale score (74%), and perfusion imaging mismatch (43%). Premorbid mRS score determination in the hyperacute setting accurately matched retrospectively collected data from the hospital admission in only 140 patients (46.8%). Physicians correctly predicted the patient’s 90 day mRS tertile (0–2, 3–4, or 5–6) and final modified Thrombolysis in Ischemic Cerebral Infarction score preprocedure in only 44.2% and 44.3% of patients, respectively. Clinicians tended to overestimate the influence of occlusion site and perfusion imaging on outcomes, while underestimating the importance of pre-morbid mRS.ConclusionsThis is the first prospective study to evaluate neurointerventionalists’ ability to accurately predict clinical outcome after MT. Overall, neurointerventionalists performed poorly in prognosticating patient 90 day outcomes, raising ethical questions regarding whether MT should be withheld in patients with emergent large vessel occlusions thought to have a poor prognosis.

BackgroundRecent clinical trials have shown that mechanical thrombectomy is superior to medical management for large vessel occlusion for up to 24 hours from onset. Our objective is to examine the safety and efficacy of thrombectomy beyond the standard of care window.MethodsA retrospective review was undertaken of the multicenter Stroke Thrombectomy and Aneurysm Registry (STAR). We identified patients who underwent mechanical thrombectomy for large vessel occlusion beyond 24 hours. We selected a matched control group from patients who underwent thrombectomy in the 6–24-hour window. We used functional independence at 3 months as our primary outcome measure.ResultsWe identified 121 patients who underwent thrombectomy beyond 24 hours and 1824 in the 6–24-hour window. We selected a 2:1 matched group of patients with thrombectomy 6–24 hours as a comparison group. Patients undergoing thrombectomy beyond 24 hours were less likely to be independent at 90 days (18 (18.8%) vs 73 (34.9%), P=0.005). They had higher odds of mortality at 90 days in the adjusted analysis (OR 2.34, P=0.023). Symptomatic intracerebral hemorrhage and other complications were similar in the two groups. In a multivariate analysis only lower number of attempts was associated with good outcomes (OR 0.27, P=0.022).ConclusionsMechanical thrombectomy beyond 24 hours appears to be safe and tolerable with no more hemorrhages or complications compared with standard of care thrombectomy. Outcomes and mortality in this time window are worse compared with an earlier time window, but the rates of good outcomes may justify this therapy in selected patients.

OBJECTIVETraditionally, stent-assisted coiling and balloon remodeling have been the primary endovascular treatments for wide-necked intracranial aneurysms with complex morphologies. PulseRider is an aneurysm neck reconstruction device that provides parent vessel protection for aneurysm coiling. The objective of this study was to report early postmarket results with the PulseRider device.METHODSThis study was a prospective registry of patients treated with PulseRider at 13 American neurointerventional centers following FDA approval of this device. Data collected included clinical presentation, aneurysm characteristics, treatment details, and perioperative events. Follow-up data included degree of aneurysm occlusion and delayed (> 30 days after the procedure) complications.RESULTSA total of 54 aneurysms were treated, with the same number of PulseRider devices, across 13 centers. Fourteen cases were in off-label locations (7 anterior communicating artery, 6 middle cerebral artery, and 1 A1 segment anterior cerebral artery aneurysms). The average dome/neck ratio was 1.2. Technical success was achieved in 52 cases (96.2%). Major complications included the following: 3 procedure-related posterior cerebral artery strokes, a device-related intraoperative aneurysm rupture, and a delayed device thrombosis. Immediately postoperative Raymond-Roy occlusion classification (RROC) class 1 was achieved in 21 cases (40.3%), class 2 in 15 (28.8%), and class 3 in 16 cases (30.7%). Additional devices were used in 3 aneurysms. For those patients with 3- or 6-month angiographic follow-up (28 patients), 18 aneurysms (64.2%) were RROC class 1 and 8 (28.5%) were RROC class 2.CONCLUSIONSPulseRider is being used in both on- and off-label cases following FDA approval. The clinical and radiographic outcomes are comparable in real-world experience to the outcomes observed in earlier studies. Further experience is needed with the device to determine its role in the neurointerventionalist’s armamentarium, especially with regard to its off-label use.

BackgroundClot density (Hounsfield units, HU) and perviousness (post-contrast increase in the HU of clot) are thought to be associated with clot composition. We evaluate whether these imaging characteristics were associated with angiographic outcomes of aspiration and stent retriever thrombectomy in COMPASS: a trial of aspiration thrombectomy versus stent retriever thrombectomy as first-line approach for large vessel occlusion.MethodsClot density and perviousness were measured by two independent operators who were blind to all the final angiographic and clinical outcomes. The association of clot density and perviousness with the Thrombolysis In Cerebral Infarction (TICI) scale after first pass was assessed using univariate and multivariate analysis.ResultsAmong all patients enrolled in COMPASS, 165 were eligible for the post-hoc analysis (81 patients in the aspiration first and 84 in the stent retriever first groups). Overall mean perviousness of clot was significantly higher in patient with mTICI 2b-3 after first pass (28.6±22.9 vs 20.3±19.2, p=0.017). Mean perviousness among patients who achieved TICI 2c/3 versus TICI 2b versus TICI 0-2a in the aspiration first group varied significantly (32.6±26.1, 35.3±24.4, and 17.7±13.1, p=0.013). The association of perviousness with first pass success was not significant in the stent retriever group. Using multivariate analysis, high perviousness (defined as cut-off >27.6) was an independent predictor of TICI 2b-3 (OR 3.82, 95% CI 1.10 to 13.19; p=0.034).ConclusionsClot perviousness is associated with first pass angiographic success in patients treated with the aspiration first approach for thrombectomy.

To assess the impact of COVID-19 on neurovascular research and deal with the challenges imposed by the pandemic.MethodsA survey-based study focused on randomized controlled trials (RCTs) and single-arm studies for acute ischemic stroke and cerebral aneurysms was developed by a group of senior neurointerventionalists and sent to sites identified through the clinical trials website (https://clinicaltrials.gov/), study sponsors, and physician investigators.ResultsThe survey was sent to 101 institutions, with 65 responding (64%). Stroke RCTs were being conducted at 40 (62%) sites, aneurysm RCTs at 22 (34%) sites, stroke single-arm studies at 37 (57%) sites, and aneurysm single-arm studies at 43 (66%) sites. Following COVID-19, enrollment was suspended at 51 (78%) sites—completely at 21 (32%) and partially at 30 (46%) sites. Missed trial-related clinics and imaging follow-ups and protocol deviations were reported by 27 (42%), 24 (37%), and 27 (42%) sites, respectively. Negative reimbursements were reported at 17 (26%) sites. The majority of sites, 49 (75%), had put new trials on hold. Of the coordinators, 41 (63%) worked from home and 20 (31%) reported a personal financial impact. Remote consent was possible for some studies at 34 (52%) sites and for all studies at 5 (8%) sites. At sites with suspended trials (n=51), endovascular treatment without enrollment occurred at 31 (61%) sites for stroke and 23 (45%) sites for aneurysms. A total of 277 patients with acute ischemic stroke and 184 with cerebral aneurysms were treated without consideration for trial enrollment.ConclusionWidespread disruption of neuroendovascular trials occurred because of COVID-19. As sites resume clinical research, steps to mitigate similar challenges in the future should be considered.

BackgroundInfection from the SARS-CoV-2 virus has led to the COVID-19 pandemic. Given the large number of patients affected, healthcare personnel and facility resources are stretched to the limit; however, the need for urgent and emergent neurosurgical care continues. This article describes best practices when performing neurosurgical procedures on patients with COVID-19 based on multi-institutional experiences.MethodsWe assembled neurosurgical practitioners from 13 different health systems from across the USA, including those in hot spots, to describe their practices in managing neurosurgical emergencies within the COVID-19 environment.ResultsPatients presenting with neurosurgical emergencies should be considered as persons under investigation (PUI) and thus maximal personal protective equipment (PPE) should be donned during interaction and transfer. Intubations and extubations should be done with only anesthesia staff donning maximal PPE in a negative pressure environment. Operating room (OR) staff should enter the room once the air has been cleared of particulate matter. Certain OR suites should be designated as covid ORs, thus allowing for all neurosurgical cases on covid/PUI patients to be performed in these rooms, which will require a terminal clean post procedure. Each COVID OR suite should be attached to an anteroom which is a negative pressure room with a HEPA filter, thus allowing for donning and doffing of PPE without risking contamination of clean areas.ConclusionBased on a multi-institutional collaborative effort, we describe best practices when providing neurosurgical treatment for patients with COVID-19 in order to optimize clinical care and minimize the exposure of patients and staff.

BackgroundFew studies have examined the trends in clinical and economic outcomes of patients with acute ischemic stroke (AIS) who receive endovascular therapy (ET) in the real-world setting.ObjectiveTo evaluate characteristics and trends in clinical and economic outcomes among commercially insured patients with AIS undergoing ET between 2011 and 2017.MethodsPatients with AIS undergoing ET from January 1, 2011 to June 30, 2017 were identified from administrative claims contained in the IBM MarketScan Commercial and Medicare Supplemental databases. The Mann–Kendall trend test was performed to examine clinical and economic trends.Between 2011 and 2017, 3411 patients (mean age 62.85±15 years) with a primary diagnosis of AIS underwent ET (coverage: Commercial 59%, n=2008; Medicare Supplemental 41%, n=1403). In the Commercial cohort, discharge to home increased significantly (from 29.54% to 39.18%, pConclusionsAlthough with some variation across the samples studied, outcomes including discharge to home, length of stay, readmission, and total cost associated with endovascular stroke therapy seemed to have improved between 2011 and 2017. Index admission cost remained unchanged.

BackgroundA study was undertaken to determine the incidence of acute ischemic stroke (AIS) and strokes related to large (LVO) and medium (MVO) vessel occlusions, and to estimate annual mechanical thrombectomy (MT) volume, past trends and future growth.MethodsA population-based analysis was performed to estimate the rate of AIS, LVOs (internal carotid artery terminus, M1 branch of the middle cerebral artery, basilar artery) and MVOs (M2 and M3 branches of the middle cerebral artery, anterior and posterior cerebral arteries). MT estimates were determined from multiple governmental data sources. Annual US numbers were adjusted for population growth.ResultsThe incidence of AIS is estimated at 216 (95% CI 199 to 238)/100 000 persons/year or 718 191 (95% CI 661 483 to 791 121) AIS/year in the USA. A vascular occlusion was observed in 21% of patients with AIS (95% CI 15 to 29). The rate of LVO was 24/100 000 persons/year (95% CI 19 to 31) or 80 075 (95% CI 62 457 to 104 375) LVOs/year, and the rate of MVO was 20/100 000 persons/year or 65 798 (95% CI 45 555 to 95 110) MVOs/year. MT estimates for 2021 are 39 164 procedures with a flattening of the growth curve from 2019 (9%, 2020–2021; 4%, 2019–2020) as opposed to initial steep growth from 2015 to 2018. Current MT procedures represent 5% of all AIS, 27% of all vascular occlusions (LVO+MVO) and 38% of all LVO and M2 occlusions. The current trajectory indicates a future growth of 5–10%/year for the next several years.ConclusionA decline in MT growth is observed. The incidence of LVO+MVO is estimated at 44/100 000 persons/year or almost 144 000 large and medium vessel strokes annually. Of these, currently an estimated 27% undergo an MT procedure, indicating an opportunity for growth. Further expansion may require focusing on the elderly, medium vessel strokes and workflow efficiencies from diagnosis to treatment.

Background and Purpose: Epidemiological studies have shown racial and ethnic minorities to have higher stroke risk and worse outcomes than non-Hispanic Whites. In this cohort study, we analyzed the STAR (Stroke Thrombectomy and Aneurysm Registry) database, a multi-institutional database of patients who underwent mechanical thrombectomy for acute large vessel occlusion stroke to determine the relationship between mechanical thrombectomy outcomes and race. Methods: Patients who underwent mechanical thrombectomy between January 2017 and May 2020 were analyzed. Data included baseline characteristics, vascular risk factors, complications, and long-term outcomes. Functional outcomes were assessed with respect to Hispanic status delineated as non-Hispanic White (NHW), non-Hispanic Black (NHB), or Hispanic patients. Multivariate analysis was performed to identify variables associated with unfavorable outcome or modified Rankin Scale ≥3 at 90 days. Results: Records of 2115 patients from the registry were analyzed. Median age of Hispanic patients undergoing mechanical thrombectomy was 60 years (72–84), compared with 63 years (54–74) for NHB, and 71 years (60–80) for NHW patients ( P P P P Conclusions: Hispanic patients are less likely to have favorable outcome at 90 days following mechanical thrombectomy compared to NHW or NHB patients. Further prospective studies are required to validate our findings.

Introduction Limited data is available about the outcomes of mechanical thrombectomy (MT) in stroke patients presenting with a large core infarct. We aim to investigate the safety and efficacy of MT in patients with large vessel occlusion and Alberta Stroke Program Early CT Score (ASPECTS) of 2-5. Methods Data from Stroke Thrombectomy and Aneurysm Registry (STAR), which combined the prospectively maintained databases of 28 thrombectomy-capable stroke centers in the US, Europe, and Asia, was interrogated. We identified thrombectomy patients presenting with an occlusion in the Internal carotid artery (ICA) or M1 segment of the middle cerebral artery (MCA). Multivariable regression analysis was performed to assess factors associated with favorable 90-day outcome (modified Rankin scale 0-3), including interaction terms between ASPECTS 2-5 and receiving MT in the extended window (≥ 6 hours from symptom-onset). Results Among MT patients who presented with ICA or M1 occlusion, 2132 had ASPECTS≥6 and 213 patients had ASPECTS 2-5. Patients in the low ASPECTS group were younger (70 vs. 72 years old, P=0.003) and more likely to present with an ICA occlusion (47.9% vs. 28.8%, P Conclusion More than one in three patients presenting with ASPECTS (2-5) may achieve favorable 90-day functional outcome following MT. Favorable outcome was 4 times higher in low ASPECTS patients who had successful recanalization. The effect of low ASPECTS on 90-day outcome did not differ in patients presenting in the early versus extended MT window. Disclosures E. Almallouhi: None. S. Al Kasab: None. Z. Hubbard: None. G. Porto: None. A. Alawieh: None. R. Chalhoub: None. E. Bass: None. P. Jabbour: None. R. Starke: None. S. Wolfe: None. A. Arthur: None. I. Maier: None. J. Grossberg: None. A. Rai: None. M. Park: None. J. Mascitelli: None. M. Psychogios: None. R. De Leacy: None. D. Raper: None. T. Dumont: None. M. Levitt: None. A. Polifka: None. J. Osbun: None. R. Crosa: None. J. Kim: None. W. Casagrande: None. M. Mokin: None. C. Matouk: None. A. Shaban: None. I. Fragata: None. A. Yoo: None. A. Spiotta: 1; C; Stryker, Penumbra, and Medtronic. 2; C; Penumbra, Stryker, Cerenovus, Terumo.

Introduction Chronic subdural hematoma (cSDH) is one of the most common neurosurgical diseases with an incidence of 1-5.3 cases per 100,000 that increases significantly with age. When symptomatic, these lesions are often treated by surgery, an approach which does not directly address the underlying pathophysiology of chronic inflammation and neovascularization of the dura and has a high incidence of recurrence. Middle meningeal artery (MMA) embolization has emerged as a potential minimally invasive endovascular treatment option that may substitute for surgery or serve as an adjunct. TRUFILL n-BCA is potentially well suited as a liquid embolic in this procedure given that it is non-caustic, rapidly deployed, and able to be injected in a highly targeted fashion. Here we present the protocol for a randomized clinical trial to evaluate the safety and effectiveness of n-BCA embolization of the MMA for the treatment of cSDH. Methods This investigational trial is a prospective, multi-center, open-label, randomized controlled study in which up to 376 subjects will be randomized to receive standard of care (SOC) alone or SOC and TRUFILL n-BCA MMA embolization for the treatment of cSDH. The study is designed to evaluate the effectiveness and safety of MMA in two cohorts - a surgical cohort and a non-surgical cohort. Results Study EndpointsThe primary study effectiveness endpoint is the incidence of residual or re-accumulation of the cSDH (>10 mm) at 6 months as assessed by an independent core laboratory OR re-operation or surgical procedure on the hematoma within 6 months post randomization. Secondary effectiveness endpoints include mean reduction of hematoma volume at 3, 6 and 12 months compared to baseline, reduction > 50% in hematoma volume at 3, 6 and 12 months as well as others. Secondary safety endpoints include death, stroke, myocardial infarction or thromboembolic complications within 3, 6 and 12 months as well as others. Secondary health economics endpoints include hospital days, intensive care unit days, and change in the EQ-5D-5L score at discharge and 6 months compared to baseline. Conclusion Middle meningeal artery embolization with n-BCA is an emerging treatment strategy for cSDH. An appropriately powered trial like the MEMBRANE Study will provide high level evidence on the potential safety and efficacy of this treatment paradigm. Disclosures C. Kellner: 1; C; Penumbra, Siemens, Cerebrotech, Viz.AI, Minnetronix. 4; C; Metis Innovative. F. Al-Mufti: None. R. Gupta: None. B. Jankowitz: None. R. Starke: None. A. Rai: None.

BackgroundAtrial fibrillation (AF) associated ischemic stroke is associated with worse functional outcomes, less effective recanalization, and increased rates of hemorrhagic complications after intravenous thrombolysis (IVT). Conversely, AF is not associated with hemorrhagic complications or functional outcomes in patients undergoing mechanical thrombectomy (MT). This differential effect of MT and IVT in AF associated stroke raises the question of whether bridging thrombolysis increases hemorrhagic complications in AF patients undergoing MT.MethodsThis international cohort study of 22 comprehensive stroke centers analyzed patients with large vessel occlusion (LVO) undergoing MT between June 1, 2015 and December 31, 2020. Patients were divided into four groups based on comorbid AF and IVT exposure. Baseline patient characteristics, complications, and outcomes were reported and compared.Results6461 patients underwent MT for LVO. 2311 (35.8%) patients had comorbid AF. In non-AF patients, bridging therapy improved the odds of good 90 day functional outcomes (adjusted OR (aOR) 1.29, 95% CI 1.03 to 1.60, p=0.025) and did not increase hemorrhagic complications. In AF patients, bridging therapy led to significant increases in symptomatic intracranial hemorrhage and parenchymal hematoma type 2 (aOR 1.66, 1.07 to 2.57, p=0.024) without any benefit in 90 day functional outcomes. Similar findings were noted in a separate propensity score analysis.ConclusionIn this large thrombectomy registry, AF patients exposed to IVT before MT had increased hemorrhagic complications without improved functional outcomes, in contrast with non-AF patients. Prospective trials are warranted to assess whether AF patients represent a subgroup of LVO patients who may benefit from a direct to thrombectomy approach at thrombectomy capable centers.

IntroductionThe endovascular stent-assisted coiling approach for the treatment of cerebral aneurysms is evolving rapidly with the availability of new stent devices. It remains unknown how each type of stent affects the safety and efficacy of the stent-coiling procedure.MethodsThis study compared the outcomes of endovascular coiling of cerebral aneurysms using Neuroform (NEU), Enterprise (EP), and Low-profile Visualized Intraluminal Support (LVIS) stents. Patient characteristics, treatment details and angiographic results using the Raymond–Roy grade scale (RRGS), and procedural complications were analyzed in our study.ResultsOur study included 659 patients with 670 cerebral aneurysms treated with stent-assisted coiling (NEU, n=182; EP, n=158; LVIS, n=330) that were retrospectively collected from six academic centers. Patient characteristics included mean age 56.3±12.1 years old, female prevalence 73.9%, and aneurysm rupture on initial presentation of 18.8%. We found differences in complete occlusion on baseline imaging, defined as RRGS I, among the three stents: LVIS 64.4%, 210/326; NEU 56.2%, 95/169; EP 47.6%, 68/143; P=0.008. The difference of complete occlusion on 10.5 months (mean) and 8 months (median) angiographic follow-up remained significant: LVIS 84%, 251/299; NEU 78%, 117/150; EP 67%, 83/123; P=0.004. There were 7% (47/670) intra-procedural complications and 11.5% (73/632) post-procedural-related complications in our cohort. Furthermore, procedure-related complications were higher in the braided-stents vs laser-cut, P=0.002.ConclusionsThere was a great variability in techniques and choice of stent type for stent-assisted coiling among the participating centers. The type of stent was associated with immediate and long-term angiographic outcomes. Randomized prospective trials comparing the different types of stents are warranted.

IntroductionAccurate estimation of the incidence of large vessel occlusion (LVO) is critical for planning stroke systems of care and approximating workforce requirements. This systematic review aimed to estimate the prevalence of LVO among patients with acute ischemic stroke (AIS), with emphasis on definitions and methods used by different studies.MethodsA systematic literature review was performed to search for articles on the prevalence of LVO and AIS. All articles describing the frequency of LVO frequency among AIS patients were included. Studies without consecutive recruitment or confirmation of LVO with CT angiography or MR angiography were excluded. Heterogeneity of the studies was assessed; meta-regression was performed to estimate the effect of LVO definition and study methods on LVO prevalence.Results18 articles met the inclusion criteria: 5 studies presented population based estimates; 13 provided single hospital experiences (5 prospective, 8 retrospective). The AIS denominator (number of all AIS) from which LVO rates were generated was variable. Nine different definitions were used, based on occlusion site. Significant heterogeneity existed among the studies (I2=99%, PConclusionThe heterogeneity of LVO estimates was remarkably high. The method of AIS denominator determination was the most significant predictor of LVO estimates. Studies with a standardized LVO definition and methods of AIS estimation are necessary to estimate the true prevalence of LVO among patients with AIS.

BackgroundThrombectomy is an efficacious treatment for acute ischemic stroke (AIS). However, relatively few studies to date have specifically examined the impact and clinical implications of age on outcomes for thrombectomy in anterior AIS.ObjectiveTo provide a snapshot of patient metrics and outcomes with respect to age following thrombectomy for anterior AIS to supplement the current body of data for predictors of clinical outcomes in a real-world setting.MethodsData were collected for 20 consecutive patients with AIS treated with thrombectomy at 15 high-volume stroke centers across North America between 2015 and 2016. Patients with anterior occlusions were dichotomized based on whether they were older or younger than 80 years. Ordinal logistic regression analyzed how clinical variables impacted disability using 90-day modified Rankin Scale (mRS) scores.ResultsAdequate revascularization (TICI ≥2B) was achieved in 92.3% of patients aged ConclusionThis analysis affirms age is a significant determinant of 90-day mRS scores following thrombectomy for large vessel anterior AIS. Further investigation into risks faced by elderly patients during thrombectomy may provide actionable information to help refine patient selection and improve outcomes.

BackgroundPolymer coating embolism due to vascular medical device use is an increasingly recognized iatrogenic complication. This phenomenon has been linked with various adverse effects including neuroinflammation, acute ischemic stroke, cerebral hemorrhage, and death. Notably, procedure- and device-specific risks of this complication are poorly investigated. In this study, we evaluate the detectable frequency of intra-arterial polymer coating delamination among patients who underwent endovascular thrombectomy for treatment of acute ischemic stroke due to large vessel occlusion.MethodsNinety-two cerebral thrombectomy specimens were retrospectively analyzed for the presence of polymer coating particulates. Histologic findings were correlated with demographic and procedural details and patient outcomes.ResultsEvidence of polymer coating deposition was found in 30 of 92 extracted thrombi (33%). No correlation between intrathrombus polymer deposition and use of a specific thrombectomy device such as a stent retriever, aspiration catheter, or guide catheter was found. However, heterogeneous patterns of device use suggest a number of culprit devices. A trend toward longer procedure times and multiple thrombectomy passes was noted in positive cases. Intrathrombus polymer deposition was not associated with adverse clinical outcomes as measured by the 90-day modified Rankin Scale (mRS); however, small sample size and follow-up intervals limit interpretation. Ninety-day outcomes based on mRS may not fully capture the clinical effects of acute and/or delayed intracerebral polymer complications.ConclusionIn light of documented adverse neurologic effects, the frequency of intrathrombus polymer particulates indicates the need for consensus testing methods and large-scale long-term prospective clinical device trials, with inclusion of relevant endpoints to better assess biomaterial and device risks to patients.

Background and Purpose— Mechanical thrombectomy (MT) devices have led to improved reperfusion and clinical outcomes in acute ischemic stroke patients with emergent large vessel occlusions; however, less than one-third of patients achieve complete reperfusion. Use of intraarterial thrombolysis in the context of MT may provide an opportunity to enhance these results. Here, we evaluate the use of intraarterial rtPA (recombinant tissue-type plasminogen activator) as rescue therapy (RT) after failed MT in the North American Solitaire Stent-Retriever Acute Stroke registry. Methods— The North American Solitaire Stent-Retriever Acute Stroke registry recruited sites within North America to submit data on acute ischemic stroke patients treated with the Solitaire device. After restricting the population of 354 patients to use of RT and anterior emergent large vessel occlusions, we compared patients who were treated with and without intraarterial rtPA after failed MT. Results— A total of 37 and 44 patients was in the intraarterial rtPA RT and the no intraarterial rtPA RT groups, respectively. Revascularization success (modified Thrombolysis in Cerebral Infarction ≥2b) was achieved in more intraarterial rtPA RT patients (61.2% versus 46.6%; P =0.13) with faster times to recanalization (100±85 versus 164±235 minutes; P =0.36) but was not statistically significant. The rate of symptomatic intracranial hemorrhage (13.9% versus 6.8%; P =0.29) and mortality (42.9% versus 44.7%; P =0.87) were similar between the groups. Good functional outcome (modified Rankin Scale score of ≤2) was numerically higher in intraarterial rtPA patients (22.9% versus 18.4%; P =0.64). Further restriction of the RT population to M1 occlusions only and time of onset to groin puncture ≤8 hours, resulted in significantly higher successful revascularization rates in the intraarterial rtPA RT cohort (77.8% versus 38.9%; P =0.02). Conclusions— Intraarterial rtPA as RT demonstrated a similar safety and clinical outcome profile, with higher reperfusion rates achieved in patients with M1 occlusions. Prospective studies are needed to delineate the role of intraarterial thrombolysis in MT.

Endovascular thrombectomy (ET) for acute ischemic stroke is the current standard of care. Although successful ET has high efficacy in improving functional outcomes, the decision to abort a long procedure remains a challenge. Longer procedure time (PT) has been associated with lower rates of functional independence.The objective of this study was to evaluate the impact of PT on outcomes and complications after ET using different techniques at a multicenter level and to define the risk of procedure extension in different patient cohorts.Patients undergoing ET with a stent retriever (SR) or a direct aspiration at first pass technique at 7 U.S. centers between June 2013 and February 2018 were reviewed from prospectively maintained databases that include baseline variables and technical and clinical outcomes. Multivariate analyses were used to assess impact of PT on 90-day modified Rankin scores, successful recanalization, post-procedural symptomatic hemorrhage (sICH), and complications.The study included 1,359 patients and demonstrated a decreased likelihood of good functional outcomes (modified Rankin score 0 to 2) when PT extended beyond 30 min (p 0.01). Rates of sICH and complications increased exponentially with PT (doubling rates of 26 and 50 min, respectively). The cumulative rate of successful recanalization and good outcomes plateaued after 60 min of PT. In patients with PT30 min, fewer attempts predicted the success of ET and good outcomes (p 0.01). Successful recanalization was achieved faster with the direct aspiration at first pass technique than in SR. The direct aspiration technique was more sensitive to PT than SR, and posterior stroke was more sensitive to PT than anterior stroke.Longer ET procedures lead to lower rates of functional independence and higher rates of sICH and complications. Exceeding 60 min or 3 attempts should trigger careful assessment of futility and risks of continuing the procedure.

Summary Background Stent retriever thrombectomy of large-vessel occlusion results in better outcomes than medical therapy alone. Alternative thrombectomy strategies, particularly a direct aspiration as first pass technique, while promising, have not been rigorously assessed for clinical efficacy in randomised trials. We designed COMPASS to assess whether patients treated with aspiration as first pass have non-inferior functional outcomes to those treated with a stent retriever as first line. Methods We did a multicentre, randomised, open label, blinded outcome, core lab adjudicated non-inferiority trial at 15 sites (ten hospitals and four specialty clinics in the USA and one hospital in Canada). Eligible participants were patients presenting with acute ischaemic stroke from anterior circulation large-vessel occlusion within 6 h of onset and an Alberta Stroke Program Early CT Score of greater than 6. We randomly assigned participants (1:1) via a central web-based system without stratification to either direct aspiration first pass or stent retriever first line thrombectomy. Those assessing primary outcomes via clinical examinations were masked to group assignment as they were not involved in the procedures. Physicians were allowed to use adjunctive technology as was consistent with their standard of care. The null hypothesis for this study was that patients treated with aspiration as first pass achieve inferior outcomes compared with those treated with a stent retriever first line approach. The primary outcome was non-inferiority of clinical functional outcome at 90 days as measured by the percentage of patients achieving a modified Rankin Scale score of 0–2, analysed by intent to treat; non-inferiority was established with a margin of 0·15. All randomly assigned patients were included in the safety analyses. This trial is registered at ClinicalTrials.gov, number: NCT02466893. Findings Between June 1, 2015, and July 5, 2017, we assigned 270 patients to treatment: 134 to aspiration first pass and 136 to stent retriever first line. A modified Rankin score of 0–2 at 90 days was achieved by 69 patients (52%; 95% CI 43·8–60·3) in the aspiration group and 67 patients (50%; 41·6–57·4) in the stent retriever group, showing that aspiration as first pass was non-inferior to stent retriever first line (p non-inferiority =0·0014). Intracranial haemorrhage occurred in 48 (36%) of 134 in the aspiration first pass group, and 46 (34%) of 135 in the stent retriever first line group. All-cause mortality at 3 months occurred in 30 patients (22%) in both groups. Interpretation A direct aspiration as first pass thrombectomy conferred non-inferior functional outcome at 90 days compared with stent retriever first line thrombectomy. This study supports the use of direct aspiration as an alternative to stent retriever as first-line therapy for stroke thrombectomy. Funding Penumbra.

Background Liquid embolic systems (LES) such as n-butyl cyanoacrylate-based TRUFILL® and ethylene vinyl-alcohol copolymer-based OnyxTM are widely used for the embolization of brain arteriovenous malformations (bAVMs). The purpose of this study was to compare hospital cost and length of stay (LOS) among unruptured bAVM patients undergoing embolization procedures with TRUFILL versus Onyx LES. Methods Adult patients with unruptured bAVMs undergoing endovascular embolization with TRUFILL or Onyx LES between January 1, 2010 and June 30, 2020 were identified from the Premier Healthcare Database. Baseline covariates among the two groups were balanced using propensity score matching. Outcomes including total procedure cost, supply cost, and LOS were examined. A Generalized Estimating Equation model was used to assess outcomes in the matched cohorts. Results A total of 1072 patients were included in the study; 140 embolized with TRUFILL (mean age 47.06 [15.72] years, 45.70% male) and 932 embolized with Onyx (mean age 46.80 [16.65] years, 52.30% male). In the post-match cohort, the total procedure costs were lower for the TRUFILL (n = 130) versus Onyx (n = 333) group, though not significantly ($36,798 vs. $40,988; odds ratio [OR] = 0.90, 95% confidence interval [CI]: 0.73–1.10; p = 0.30). However, supply cost was significantly lower for hospitalizations with TRUFILL compared to Onyx use ($13,281 vs. $16,371, OR = 0.81, 95% CI: 0.68, 0.98; p = 0.026). Hospital LOS was similar in these two groups (TRUFILL: 4.05 vs. Onyx: 4.06 days; OR = 1.00, 95% CI: 0.70, 1.42; p = 0.99). Conclusions In a large, multi-center, real-world sample of patients undergoing bAVM embolization, TRUFILL use was associated with significantly lower supply cost compared to Onyx use.

BackgroundThe efficacy of endovascular thrombectomy (ET) for acute ischemic stroke (AIS) in octogenarians is still controversial.ObjectiveTo evaluate, using a large multicenter cohort of patients, outcomes after ET in octogenarians compared with younger patients.MethodsData from prospectively maintained databases of patients undergoing ET for AIS at seven US-based comprehensive stroke centers between January 2013 and January 2018 were reviewed. Demographic, procedural, and outcome variables were collected. Outcomes included 90-day modified Rankin Scale (mRS) score, postprocedural National Institutes of Health Stroke Scale score, postprocedural hemorrhage, and mortality. Univariate and multivariate analyses were performed to assess the independent effect of age ≥80 on outcome measures. Subgroup analyses were also performed based on location of stroke, success of recanalization, or ET technique used.ResultsRates of functional independence (mRS score 0–2) after ET in elderly patients were significantly lower than for younger counterparts. Age ≥80 was independently associated with increased mortality and poor outcome. Age ≥80 showed an independent negative prognostic effect on outcome even when patients were divided according to thrombectomy technique, location of stroke, or success of recanalization. Age ≥80 independently predicted higher rate of postprocedural hemorrhage, but not success of recanalization. Baseline deficit and number of reperfusion attempts, but not Thrombolysis in Cerebral Infarction score were associated with lower odds of good outcome.ConclusionThe large effect size of ET on AIS outcomes is significantly diminished in the elderly population when using comparable selection criteria to those used in younger counterparts. This raises concerns about the risk–benefit ratio and the cost-effectiveness of performing this procedure in the elderly before optimizing patient selection.

* on behalf of the Stroke Thrombectomy and Aneurysm Registry (STAR) Collaborators Introduction: Intravenous thrombolysis complications are enriched in AF associated stroke, as these patients have worse functional outcomes, less effective recanalization, and increased rates of hemorrhagic complications. These data suggest that AF patients may be at particularly high risk for complications of bridging therapy for large vessel occlusions treated with mechanical thrombectomy (MT). Here we determine whether clinical outcomes differ in AF associated stroke treated with MT and bridging therapy. Methods: We performed a retrospective cohort study of the Stroke and Aneurysm Registry (STAR) from January 2015 to December 2018 and identified 4,169 patients who underwent MT for an anterior circulation stroke, 1,517 (36.4 %) of which had comorbid AF. Prospectively defined baseline characteristics and clinical outcomes were compared. Results: Hemorrhagic complications after MT were similar in patients with or without AF. In patients without AF, bridging therapy improved 90-day outcomes (aOR 1.32, 1.02-1.74, p Conclusions: Bridging therapy in AF patients undergoing thrombectomy independently increased the odds of intracranial hemorrhage and did not improve functional outcomes. AF patients may represent a high-risk subgroup for thrombolytic complications. Randomized trials are warranted to determine whether patients with AF associated stroke may benefit by deferring bridging therapy at thrombectomy-capable centers.

Introduction: The benefit of thrombectomy for large vessel occlusion (LVO) is well proven. There is minimal data on concurrent thrombectomy for multi-territory occlusions. Methods: We reviewed the STAR registry from 2015-8 for patients treated with either right and left sided thrombectomy or anterior and posterior circulation thrombectomy at 15 comprehensive stroke centers. Results: There were 4966 patients in the study period who had completed outcome data and LVO thrombectomy. 38 (0.8%) underwent endovascular thrombectomy for multi-territory occlusions. 26% had bilateral occlusions and 74% had anterior and posterior circulation occlusions. Among the 38, 50% were female, 49% were white, and 91% had a prestroke mRS6 and 55% received iv t-pa. 83% of patients had successful recanalization (TICI 2B/3) for both territories. The overall complication rate was 15%. 5% of patients had sICH or PH2. 26% of patients had a 90day mRS Conclusion: With similar selection to single territory LVOs, good outcome can be achieved in multi-territory infarction with reasonable procedure time and no additional risk of hemorrhage or poor outcome.

Introduction: Successful first pass (SFP) has been identified as a key benchmark of the success of mechanical thrombectomy (MT). However, studies that evaluate the predictors and outcomes of SFP using ADAPT (A Direct Aspiration first Pass Technique) are limied by the small number of patients or single center design. Methods: We used data from the prospectively collected data from 28 stroke centers that are included in the Stroke Thrombectomy and Aneurysm Registry (STAR). Patients with middle cerebral artery (MCA) occlusions at the level of M1 or M2 segments were included. SFP was defined by achieving modified Thrombolysis in Cerebral Infarction (mTICI) score≥2b with a single aspiration attempt. A multivariable logistic regression analysis was used to assess the predictors of SFP and evaluate the relationship between SFP and favorable 90-day outcome (90-day modified Rankin scale ≤2). Results: Out of 6123 patients included in STAR, 1002 (16.4%) underwent MT of M1 or M2 occlusion using ADAPT technique. SFP was achieved in 390 (38.9%) patients. SFP patients were older (72 vs. 69, P=0.007), had higher Alberta Stroke Program Early CT Score (ASPECTS) on presentation (9 vs. 8, P=0.018) (Table 1). On multivariable analysis, neither age (aOR 1.006, 95% CI 0.996-1.016, P=0.252) nor ASPECTS (aOR 1.055, 95% CI 0.976-1.141, P=0.179) were independent predictor of SFP. Importantly, SFP was independently associated with favorable 90-day outcome (aOR 2.769, 95% CI 1.988-3.858, P Conclusion: In this cohort of patients with M1 or M2 occlsuion undergoing MT using ADAPT technique, patients who had SFP were older and had better ASPECTS. However, both age and ASPECTS were not independently associated with SFP. Also, patients who had SFP were almost 3 times more likely to achieve favorable 90-day outcome.

Introduction: Patients with poor baseline images were excluded from most clinical trials so the data about whether these patients could benefit from MT remains unknown. In this study, we aim to investigate the safety and efficacy of MT in patients with large vessel occlusion (LVO) and large core infarct (LCI). Methods: The Stroke Thrombectomy and Aneurysm Registry (STAR) was interrogated. We included thrombectomy patients presenting with LVO within 24 hours and with a LCI as defined by Alberta Stroke Program Early CT Score (ASPECTS) < 6. Patients presenting within 6 hours of last known normal (LKN) were considered in the early window and patients presenting after 6 hours were considered in the late window. 90-day outcomes were assessed. We used a logistic regression model to assess the factors associated with good 90-day outcome in patients in the early and late windows. Results: 144 patients were included in this study (table). Median age was 69 and 92 (64%) patients were treated in the early MT window. ICA was the most common site of occlusion (48.6%) and ADAPT was used in 34.7%. Admission NIHSS was 17.5. Successful recanalization (TICI>2b) was achieved in 84.7% and median procedure time was 54 minutes. sICH hemorrhage was observed in 22 (15.3%). Median mRS was 4 at 90 days. Favorable outcome was observed in 41 patients (28.5%) and mortality occurred in in 59 (41%). There was no difference in 90-day functional outcome between patients in early and late windows. In patients presenting in the early window, age (aOR=0.905, p=0.0002) and baseline NIHSS (aOR=0.909, p=0.0423) were independently associated with 90-day outcome. In patients presenting in the late window, only age (aOR=0.934, p=0.0069) was independently associated with good outcome. Conclusion: More than one in four patients presenting with ASPECTS

Introduction: Previous studies have reported that Hispanic stroke patients have limited access to mechanical thrombectomy (MT) compared to other ethnic groups. This has resulted in worse stroke outcomes in this group. However, limited data is available about the outcomes of MT in Hispanic patients. Methods: We used data from the Stroke Thrombectomy and Aneurysm Registry (STAR) that combined the prospectively maintained databases of 28 thrombectomy-capable stroke centers in the US, Europe, and Asia. Consecutive patients who underwent MT were included in these analyses and patients were divided into 2 groups (Hispanics vs. non-Hispanics). Baseline features, time from symptom onset, thrombolysis receipt, final thrombolysis in cerebral infarction (TICI) score, symptomatic hemorrhage, and 90-day functional outcomes (measured by modified Rankin scale-mRS) were compared between Hispanic and non-Hispanics patients. A generalized linear model with logit link was used to assess the relationship between ethnicity and favorable outcomes at 90-day (mRS 0-2) controlling for confounders. Results: We included 2015 patients in these analyses. Of those, 285 (14.1%) were Hispanic. As shown in table 1, Hispanic patients were older (72 vs. 70, p=0.007), more likely to have diabetes (41.1% vs. 26.5%, p Conclusion: Hispanic patients receiving MT have higher rate of stroke risk factors including diabetes and hypertension. Moreover, Hispanic ethnicity was independently associated with lower probability of favorable 90-day outcome.

Introduction: Recent trials have proven safety and efficacy of mechanical thrombectomy for patients presenting with emergent large vessel occlusion beyond 6 hours of symptom onset. While evidence supports using baseline CT scan to evaluate the candidacy for mechanical thrombectomy for patients presenting in the early window, late window trials have used advanced imaging such as CT and MR perfusion. We aim to assess outcomes of MT stratified by admission Alberta Stroke Program Early CT Score (ASPECTS). Methods: We used data from the prospectively maintained registries of 28 stroke centers in the Stroke Thrombectomy and Aneurysm (STAR) collaboration. Demographics, comorbidities, LVO site, ASPECTS, MT technique, radiographic and clinical outcome data were collected. Patients with M1 or ICA occlusion were included in these analyses. Multivariable analysis was performed using a generalized linear model with logit link to assess for variables associated with favorable outcomes. Results: 3356 patients in the STAR database were reviewed and 347 (10.3%) of those underwent MT in the late window (table). Median age was 69, 189 (54.5%) were female, and 181 (52.2%) were white. 295 patients ASPECTS ≥6. In this group, 200 (68.8%) had M1 occlusion, and the remaining had ICA occlusion. Aspiration thrombectomy was used in 139 (47.1%) of patients. Successful reperfusion was achieved (mTICI≥2b) in 264 (76.1%). sICH was observed in 15 (5.1%). Excellent functional outcome (mRS 0-2) was observed in 124 (42%) patients. ASPECTS score was independently associated with favorable outcomes (aOR 1.2, 95% CI 1.1-1.4, P=0.006). Conclusion: Excellent outcomes are observed in patients with good ASPECT score presenting in the late window irrespective of perfusion criteria. Admission CT scan could be used to triage patients presenting with emergent large vessel occlusion beyond 6 hours of symptom onset.

Background/Objective: Blood pressure parameters for patients undergoing mechanical thrombectomy (MT) are not clearly defined. Prior studies have shown that higher maximum and mean systolic blood pressure (SBP) is associated with adverse outcomes. Our study sought to investigate the relationship of blood pressure on clinical outcomes after successful revascularization and determine optimal thresholds for BP parameters that correlated with a poor functional outcome. Methods: This was a retrospective observational study of 88 consecutive patients who received successful MT at one comprehensive stroke center. Systolic, diastolic, and mean arterial pressure values were recorded for each patient over a 48-hour period, as well as patient age and National Institutes of Health Stroke Scale (NIHSS). Outcome measures included modified Rankin Score (mRS), intracranial hemorrhage (ICH), and mortality at time of discharge and 90 days. Both univariable and multivariable logistic regression analysis was performed to identify associations between the BP covariates and functional outcomes. Results: A higher SBP standard deviation (SD) of >14mmHg (OR=1.150) and wider SBP range >64mmHg (OR=1.037) from the mean in the first 48 hours after successful MT were associated with poor MRS at 90 days. A SBP SD>14 was also associated with mortality at 90 days. A higher age (OR=1.052) and NIHSS (OR=1.096) were also associated with a poor MRS at 90 days. A higher DBP mean (OR=1.045) was associated with a higher rate of hemorrhagic transformation (HT). Conclusions: A higher SBP variability within the first 48 hours after successful MT is associated with a higher likelihood of poor 90-day functional outcome and mortality, and a higher mean DBP is associated with a higher rate of HT.

BackgroundThe PerfusiOn imaging Selection of Ischemic sTroke patIents for endoVascular thErapy (POSITIVE) trial was designed to evaluate functional outcome in patients with emergent large vessel occlusion (ELVO) presenting within 0–12 hours with pre-specified bifurcated arms of early and late window presentation, who were selected for endovascular thrombectomy with non-vendor specific commercially available perfusion imaging software. Recent trials demonstrating the benefit of thrombectomy up to 16–24 hours following ELVO removed equipoise to randomize late window ELVO patients and therefore the trial was halted.MethodsUp to 200 patients were to be enrolled in this FDA-cleared, prospective, randomized, multicenter international trial to compare thrombectomy and best medical management in patients with ELVO ineligible for or refractory to treatment with IV tissue plasminogen activator (IV-tPA) selected with perfusion imaging and presenting within 0–12 hours of last seen normal. The primary outcome was 90-day clinical outcome as measured by the raw modified Rankin Scale (mRS) with scores 5 and 6 collapsed (mRS shift analysis).ResultsThe POSITIVE trial suspended enrollment with the release of results from the DAWN trial and was stopped after the release of the DEFUSE 3 trial results. Thirty-three patients were enrolled (21 for medical management and 12 for thrombectomy). Twelve of the 33 patients were enrolled in the 6–12 hour cohort. Despite the early cessation, the primary outcome demonstrated statistically significant superior clinical outcomes for patients treated with thrombectomy (P=0.0060). The overall proportion of patients achieving an mRS score of 0–2 was 75% in the thrombectomy cohort and 43% in the medical management cohort (OR 4.00, 95% CI 0.84 to 19.2).ConclusionPOSITIVE supports the already established practice of delayed thrombectomy for appropriately selected patients presenting within 0–12 hours selected by perfusion imaging from any vendor. The results of the POSITIVE trial are consistent with other thrombectomy trials. The statistically significant effect on functional improvement, despite the small number of patients, reinforces the robust benefits of thrombectomy.Clinical trial registrationNCT01852201

The most common intracranial large vessel occlusion encountered in acute stroke patients presenting for consideration for mechanical thrombectomy involves the M1 segment of the MCA. Interventionalists performing endovascular stroke procedures must possess a thorough understanding of the various treatment strategies that can be utilized to revascularize the occluded M1. Using case examples, these treatment options are presented and discussed.

There has been increasing adoption of endovascular stroke treatment in the United States following multiple clinical trials demonstrating superior efficacy. Next steps in enhancing this treatment include an analysis and development of stroke systems of care geared toward efficient delivery of endovascular and comprehensive stroke care. The chapter presents epidemiological data and an overview of the current state of stroke delivery and potential improvements for the future in the light of clinical data.