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Anastomotic aneurysms are widely described in the cardiac literature; however, they have been less frequently reported in the neurological field. Historically, neurosurgeons have been treating anastomotic aneurysms arising from the superficial temporal artery to the middle cerebral artery (STA-MCA) bypass with open surgery. We proposed an endovascular treatment for our patient using the stent-assisted coiling technique, achieving good outcomes.A man in his late forties with symptomatic chronic carotid occlusion underwent direct STA-MCA bypass surgery. On follow-up images, an incidental anastomotic aneurysm was discovered. The risks and benefits of treatment or watchful waiting were addressed, and an endovascular approach was the chosen treatment technique. Such complication is widely described in the cardiac literature; however, it has scarce reports in the neurological field. Furthermore, stent-assisted coiling was performed achieving complete occlusion of the aneurysm maintaining good patency of the bypass.STA-MCA aneurysm at the site of anastomosis is a potential complication after a direct bypass. Traditional management has been reported using open surgery with clipping or wrapping of the aneurysm. However, we propose endovascular surgery as an alternative approach to such complication, achieving good clinical outcomes.

Background: Successful reperfusion is one of the strongest predictors of functional outcomes after mechanical thrombectomy (MT). Despite continuous advancements in MT technology and techniques, reperfusion failure still occurs in ≈15% to 30% of patients with large vessel occlusion strokes undergoing MT. We aim to evaluate the safety and efficacy of rescue intracranial stenting for large vessel occlusion stroke after failed MT. Methods: The SAINT (Stenting and Angioplasty in Neurothrombectomy) Study is a retrospective analysis of prospectively collected data from 14 comprehensive stroke centers through January 2015 to December 2020. Patients were included if they had anterior circulation large vessel occlusion stroke due to intracranial internal carotid artery and middle cerebral artery-M1/M2 segments and failed MT. The cohort was divided into 2 groups: rescue intracranial stenting and failed recanalization (modified Thrombolysis in Cerebral Ischemia score 0–1). Propensity score matching was used to balance the 2 groups. The primary outcome was the shift in the degree of disability as measured by the modified Rankin Scale at 90 days. Secondary outcomes included functional independence (90-day modified Rankin Scale score 0–2). Safety measures included symptomatic intracranial hemorrhage and 90-day mortality. Results: A total of 499 patients were included in the analysis. Compared with the failed reperfusion group, rescue intracranial stenting had a favorable shift in the overall modified Rankin Scale score distribution (acOR, 2.31 [95% CI, 1.61–3.32]; P P P =0.04) at 90 days. Rates of symptomatic intracerebral hemorrhage were comparable across both groups (7.1% versus 10.2%; aOR, 0.99 [95% CI, 0.42–2.34]; P =0.98). The matched cohort analysis demonstrated similar results. Specifically, rescue intracranial stenting (n=107) had a favorable shift in the overall modified Rankin Scale score distribution (acOR, 3.74 [95% CI, 2.16–6.57]; P P P =0.03) at 90 days with similar rates of symptomatic intracerebral hemorrhage (7.5% versus 11.2%; aOR, 0.87 [95% CI, 0.31–2.42]; P =0.79) compared with patients who failed to reperfuse (n=107). There was no heterogeneity of treatment effect across the prespecified subgroups for improvement in functional outcomes. Conclusions: Acute intracranial stenting appears to be a safe and effective rescue strategy in patients with large vessel occlusion stroke who failed MT. Randomized multicenter trials are warranted.

Treatment of small-caliber vessel lesions using flow diverters remains challenging because of vasculature's narrow luminal diameter and tortuosity. This in turn makes navigation and delivery of conventional devices with standard microcatheters more difficult. The Silk Vista Baby (SVB, Balt) flow diversion device was designed for ease of use in vessels with a smaller diameter, distal lesions, and 0.017 ″ microcatheter delivery systems.To report the outcomes of the SVB device on the treatment of posterior inferior cerebellar artery (PICA) aneurysms.Databases from different centers were retrospectively reviewed for PICA aneurysms treated with SVB. Demographic information, clinical presentation, radiographic characteristics, procedural complications, and immediate postprocedure outcomes were obtained.Fourteen patients harboring 15 true PICA aneurysms were treated between January 2019 and June 2021. Nine were female (n = 9/14; 64.2%), and the mean age was 51 ± 14.9 years. Most patients had previously ruptured aneurysms, treated by another endovascular technique. Six aneurysms were located distally (n = 6/15; 40%). The mean neck size was 3 mm (SD 1.35, range 2.5-5 mm), whereas the mean PICA diameter was 1.6 mm (SD 0.26, range 1.5-1.7 mm). The mean length of follow-up was 6 months (SD 8.28, range 4.5-16 months). Treatment-related adverse events included 1 case of transient hypoesthesia. Two additional events were reported, but adjudicated as unrelated to the procedure. Complete occlusion, measured as Raymond-Roy class I, was achieved in all cases.The SVB device was safely and effectively used in the treatment of PICA aneurysms. The smaller delivery system profile reduces the risk of procedure complications and creates new treatment options for distal lesions.

Introduction Mechanical thrombectomy has become the standard of care to treat acute ischemic stroke patients with large vessel occlusions. Device performance and physician technique have developed since early trials proving the efficacy of the procedure1‐3. One of these techniques, direct aspiration first pass technique (ADAPT)4involves navigating a large‐bore catheter to the face of the clot and initiating suction. Navigating large‐bore catheters through intracranial neurovasculature has been accomplished using microcatheters and/or guidewires. Due to the large sizes of these aspiration catheters, the microcatheters used to help deliver the aspiration catheters into the brain form a “ledge” between the disparate lumens and prevent progression of the aspiration catheter into the distal neurovasculature and increase the risk of damaging arteries during advancement. A novel navigation support catheter, the Tenzing Delivery Catheter, has shown promising benchtop performance assisting large‐bore aspiration catheter delivery to the occlusion sitein vitro5. It demonstrated superior performance over traditional microcatheter/guidewire techniques in delivering the aspiration catheter to the occlusion in this model. While limited initial clinical experience from examining a small sample group appears to confirm this observation, a cumulative, large‐scale analysis of experience using the Tenzing catheter in clinical practice to further examine its safety, efficacy, and usability has not yet been performed. With that in mind, this study serves as an initial multicenter first‐experience investigation to assess the aforementioned factors and determine the utilization potential of Tenzing catheters. Methods This study was conducted via retrospective chart review across three institutions. Patients included in the study are 18 years old or older, underwent a thrombectomy procedure between January 1, 2020 and July 31, 2022, and whose procedures involved the use of the Tenzing delivery catheter system. Our primary outcome measures were success in delivering aspiration catheter, post treatment thrombus, and perioperative complications. Results In our sample size of n = 95, inclusive of patients from multiple institutions, it was found that in 96% of cases, the Tenzing catheter was successfully delivered to the occlusion site and successful reperfusion (mTICI less than or equal to 2b) was achieved in 90% of cases.In the majority of cases, the Tenzing delivery catheter was used to deliver an aspiration catheter to a middle cerebral artery occlusion (75%). Tenzing was advanced past the occlusion location (identified as the angiographic limit of contrast) in 59% of cases. Secondary emboli were observed 11% of the time. Other procedural complications were observed in 8% of patients while none was seen in 74%. On average, the median NIHSS decreased from 17 pre‐treatment to 10 post‐treatment. Conclusions Based on these findings, we conclude that the Tenzing Delivery Catheter is a safe and efficacious instrument in thrombectomy procedures. Given its high rate of revascularization and delivery success with few complications as demonstrated in this multicenter study.Future studies with larger patient volume are necessary to evaluate this important delivery catheter as it is used more frequently around the world.

Introduction EXCELLENT (NCT03685578; Cerenovus) is a large, prospective, international, real‐world registry of endovascular clot removal in acute ischemic stroke (AIS) with EmboTrap as the first line mechanical thrombectomy (MT) device, which included collection and analysis of the retrieved thrombus material. Methods Between September 2018 and March 2021, 1000 “all‐comer” patients were enrolled at 34 global sites (27 US, 5 EU, 1 UK, 1 Israel) and treated according to standard of care at each center (with Embrotrap as first line). The study employed blind endpoint evaluation, including a core imaging lab and an independent 90‐day mRS assessment. Retrieved clot was collected per each MT maneuver from 538 subjects across 26 sites and clot analysis was performed by independent central labs blinded to clinical data. Results mITT population included 998 subjects. Mean age was 69.9±14.18 years (range 18–102), 51.8% (517/998) subjects were female and 9.9% (97/997) had a pre‐stroke mRS 3–5. Baseline NIHSS was 15.6±6.87 (range 0–36); 10.1% (82/815) subjects had a large core (ASPECTS 0–5); 5.8% (57/990) had posterior stroke; 56.3% (523/929) underwent MT ≤ 6hrs of onset and 38.1% (380/998) received IV‐tPA prior to MT. First pass eTICI 2c‐3 was achieved in 38.3% (377/984) and final 2b‐3 in 94.5 % (930/984; median number of passes = 1) of subjects. 90‐day mRS≤2 or ≤pre‐stroke was 46.9% (429/915) and 90‐day all‐cause mortality was 19.0% (175/921). The univariate analysis of clot components showed high red blood cell and low platelet content were significant predictors of good mRS outcome (p Conclusions This large multi‐center, all‐comer cohort reflects the population undergoing thrombectomy today in a real world‐setting. Final angiographic, clinical and thrombus composition results, along with multivariate analysis of predictors of clinical outcomes, will be presented at the time of the conference.

The Woven EndoBridge (WEB) device (Terumno Corp. [parent company of Microvention]) was approved by the U.S. Food and Drug Administration as the first intrasaccular device for intracranial aneurysm treatment in December 2018. Its use has become more common since then, but both trial results and postmarket experiences have raised questions about the efficacy in achieving complete aneurysm obliteration. Retreatment after WEB embolization has not been extensively discussed. OBJECTIVE: To discuss the incidence and retreatment of aneurysms after initial WEB embolization. METHODS: Retrospective review across 13 institutions identified all occurrences of WEB retreatment within neurovascular databases. Details regarding demographics, aneurysm characteristics, treatment considerations, clinical outcomes, and aneurysm occlusion were obtained and analyzed. RESULTS: Thirty aneurysms were retreated in 30 patients in a cohort of 342 WEB-treated aneurysms. The retreatment rate was 8.8%. Endovascular methods were used for 23 cases, and 7 were treated surgically. Two aneurysms presented with rehemorrhage after initial WEB embolization. Endovascular treatments included stent-assisted coiling (12), flow diversion (7), coiling (2), PulseRider (Johnson & Johnson)–assisted coiling (1), and additional WEB placement (1). Surgical treatments included primary clipping (6) and Hunterian ligation (1). There were no major complications within the study group. CONCLUSION: WEB retreatments were successfully performed by a variety of techniques, including stent-assisted coiling, clipping, and flow diversion as the most common. These procedures were performed safely with subsequent obliteration of most aneurysms. The potential need for retreatment of aneurysms should be considered during primary WEB treatments.

Background and Purpose: The Tigertriever is a novel, radially adjustable, fully visible, stentriever that permits the operator to align radial expansion with target vessel diameters. This multicenter trial compared the Tigertriever’s effectiveness and safety compared with established stent retrievers. Methods: Single arm, prospective, multicenter trial comparing the Tigertriever to efficacy and safety performance goals derived from outcomes in 6 recent pivotal studies evaluating the Solitaire and Trevo stent-retriever devices with a lead-in and a main-study phase. Patients were enrolled if they had acute ischemic stroke with National Institutes of Health Stroke Scale score ≥8 due to large vessel occlusion within 8 hours of onset. The primary efficacy end point was successful reperfusion, defined as core laboratory-adjudicated modified Thrombolysis in Cerebral Ischemia score 2b-3 within 3 passes of the Tigertriever. The primary safety end point was a composite of 90-day all-cause mortality and symptomatic intracranial hemorrhage. Secondary efficacy end points included 3-month good clinical outcome (modified Rankin Scale score 0–2) and first-pass successful reperfusion. Results: Between May 2018 and March 2020, 160 patients (43 lead-in, 117 main phase) at 17 centers were enrolled and treated with the Tigertriever. The primary efficacy end point was achieved in 84.6% in the main-study phase group compared with the 63.4% performance goal and the 73.4% historical rate (noninferiority P P P =0.004; superiority P =0.57). Good clinical outcome was achieved in 58% at 90 days. Conclusions: The Tigertriever device was shown to be highly effective and safe compared with Trevo and Solitaire devices to remove thrombus in patients with large-vessel occlusive stroke eligible for mechanical thrombectomy. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03474549.

Background and Purpose— Because of unique attributes of mechanical thrombectomy performed between 6 and 24 hours after symptom onset in acute ischemic stroke patients, it is not known if predictors of angiographic recanalization and favorable outcome in patients treated with thrombectomy in the late (6–24 hour) time window are similar to those treated in the early time window. Methods— We analyzed data from the DAWN trial (DWI or CTP Assessment With Clinical Mismatch in the Triage of Wake-Up and Late Presenting Strokes Undergoing Neurointervention With Trevo) which enrolled patients with symptom onset 6 to 24hours after last known well and occlusion of the intracranial internal carotid artery or proximal middle cerebral artery with a mismatch between severity of clinical deficit and infarct core volume as identified by computed tomography–perfusion or diffusion magnetic resonance imaging. We evaluated the effect of tandem occlusions, periprocedural heparin use, procedural speed (from puncture to procedure completion), general anesthesia, balloon-guide catheters, thrombectomy device size, and number of passes on substantial reperfusion (modified Thrombolysis in Cerebral Infarction 2b/3) and on likelihood of obtaining a modified Rankin Scale at 3 months indicating functional independence. Results— Of 107 patients who underwent MT in the interventional arm of DAWN, substantial reperfusion and modified Rankin Scale score 0 to 2 at 3 months was seen in 90 (84%) and 52 (49%), respectively. In univariate analysis, general anesthesia (odds ratio [OR] 0.27; P =0.042) and ≥3 passes with stent retriever (OR, 0.17; P =0.002) were inversely associated with substantial reperfusion. In multivariate analyses, only ≥3 passes were associated with lack of revascularization (OR, 0.17; P =0.002). in univariate analysis ≥3 passes (OR, 0.24; P =0.003) and baseline National Institutes of Health Stroke Scale score >17 (OR, 0.19; P P =0.003) and National Institutes of Health Stroke Scale score >17 (OR, 0.19; P Conclusions— Patients requiring ≥3 thrombectomy passes had reduced substantial reperfusion and favorable outcome at 3 months in DAWN. Whether or not additional thrombectomy techniques beyond ≥3 thrombectomy passes with the Trevo stent retriever are beneficial for patient outcomes in this patient population remains to be clarified by future studies. Clinical Trial Registration— URL: https://www.clinicaltrials.gov . Unique identifier: NCT02142283.

Background and Purpose— It is unknown whether the benefit of thrombectomy in late presenting acute stroke patients with imaging evidence of clinical-infarct mismatch is different in patients presenting with wake-up stroke compared with those presenting with witnessed onset or unwitnessed onset. Methods— Prespecified secondary analysis was performed from DAWN (Diffusion Weighted Imaging [DWI] or Computerized Tomography Perfusion [CTP] Assessment With Clinical Mismatch in the Triage of Wake Up and Late Presenting Strokes Undergoing Neurointervention), a multicenter, prospective, randomized clinical trial with blinded end point assessment comparing thrombectomy with the Trevo device against standard medical therapy in patients with acute stroke and clinical-infarct mismatch presenting 6 to 24 hour after the time last seen well. For the purposes of this study, the primary outcome was the proportion of modified Rankin Scale score 0 to 2 at 90 days. Univariable analysis and multivariable logistic regression was used to assess the relationship between outcome and mode of onset. Results— All 206 enrolled patients were included in the study. Mode of onset was: wake-up stroke (55.3%, n=114), witnessed onset (12.1%, n=25), and unwitnessed onset (32.5%, n=67) with median time last seen well to randomization (13.4±3.7, 10.0±3.7, 14.1±4.9 hours) respectively. Rates of 90-day modified Rankin Scale score of 0 to 2 and symptomatic intracerebral hemorrhage in the thrombectomy arm were not statistically different across patient onset subtypes ( P =0.79 and P =0.40, respectively). The benefit of thrombectomy compared with best medical therapy was maintained across all 3 onset modes (rates of 90-day modified Rankin Scale score of 0 to 2 in patients allocated to thrombectomy versus control: wake-up stroke—49.3% versus 10.6%, witnessed onset—63.6% versus 21.4%, UW—41.4% versus 13.2%; P ×interaction=0.79). In univariable and multivariable analyses, mode of onset was not identified as a significant predictor of modified Rankin Scale score 0 to 2 at 90 days. Conclusions— In patients with acute ischemic stroke presenting between 6 and 24 hours from time last seen well and harboring clinical-infarct mismatch, the benefit of thrombectomy was similar regardless of the wake-up, unwitnessed, or witnessed mode of onset.

Background Patients presenting with large vessel occlusion and a large ischemic core (>50 mL) have been consistently undersampled in the major endovascular thrombectomy (ET) trials. As such, equipoise exists as to whether ET is associated with improved outcomes over medical therapy alone in this population. Methods Prospectively collected databases from 4 US centers were reviewed to identify patients with baseline ischemic cores >50 mL based on computed tomography perfusion imaging using RAPID software (iSchemaView), who were treated with ET or medical therapy alone between January 2014 and October 2019. Baseline characteristics, procedural information, and clinical follow‐up data were collected. A matched‐control comparison of these patients was performed. Results A total of 167 patients were included, of whom 92 received medical therapy alone and 75 underwent ET. Seventy‐five pairs were obtained after matching for baseline ischemic core volume, National Institutes of Health Stroke Scale score, and age. Rate of 90‐day good outcome was significantly higher in the ET arm (28.4% versus 4.9%, P =0.002). In univariate analysis of ET patients, the rate of good outcome was significantly higher among patients treated within P =0.02). Predictors of good outcome included age ( P =0.008), ischemic core volume ( P =0.01), and time from last known well to groin puncture ( P =0.004). Conclusions ET was associated with improved outcomes in patients with large ischemic core based on computed tomography perfusion. This association was more pronounced in patients who present early (

Background and Purpose— It is unknown whether noncontrast computed tomography (NCCT) can identify patients who will benefit from intra-arterial treatment (IAT) in the extended time window. We sought to characterize baseline Alberta Stroke Program Early CT Score (ASPECTS) in DAWN (DWI or CTP Assessment With Clinical Mismatch in the Triage of Wake-Up and Late Presenting Strokes Undergoing Neurointervention With Trevo) and to assess whether ASPECTS modified IAT effect. Methods— Core lab adjudicated ASPECTS scores were analyzed. The trial cohort was divided into 2 groups by qualifying imaging (computed tomography versus magnetic resonance imaging). ASPECTS-by-treatment interaction was tested for the trial coprimary end points (90-day utility-weighted modified Rankin Scale (mRS) score and mRS, 0–2), mRS 0 to 3, and ordinal mRS. ASPECTS was evaluated separately as an ordinal and a dichotomized (0–6 versus 7–10) variable. Results— Of 205 DAWN subjects, 123 (60%) had NCCT ASPECTS, and 82 (40%) had diffusion weighted imaging ASPECTS. There was a significant ordinal NCCT ASPECTS-by-treatment interaction for 90-day utility-weighted mRS (interaction P =0.04) and mRS 0 to 2 (interaction P =0.02). For both end points, IAT effect was more pronounced at higher NCCT ASPECTS. The dichotomized NCCT ASPECTS-by-treatment interaction was significant only for mRS 0 to 2 (interaction P =0.04), where greater treatment benefit was seen in the ASPECTS 7 to 10 group (odds ratio, 7.50 [2.71–20.77] versus odds ratio, 0.48 [0.04–5.40]). A bidirectional treatment effect was observed in the NCCT ASPECTS 0 to 6 group, with treatment associated with not only more mRS 0 to 3 outcomes (50% versus 25%) but also more mRS 5 to 6 outcomes (40% versus 25%). There was no significant modification of IAT effect by diffusion weighted imaging ASPECTS. Conclusions— Baseline NCCT ASPECTS appears to modify IAT effect in DAWN. Higher NCCT ASPECTS was associated with greater benefit from IAT. No treatment interaction was observed for diffusion weighted imaging ASPECTS.

Background and Purpose— We aimed to evaluate the current practice patterns, safety and outcomes of patients who receive endovascular therapy (EVT) having mild neurological symptoms. Methods— From Jan 2010 to Jan 2018, 127,794 ischemic stroke patients were enrolled in the Florida-Puerto Rico Stroke Registry. Patients presenting within 24 hours of symptoms who received EVT were classified into mild (National Institutes of Health Stroke Scale [NIHSS] ≤5) or moderate/severe (NIHSS>5) categories. Differences in clinical characteristics and outcomes were evaluated using multivariable logistic regression. Results— Among 4110 EVT patients (median age, 73 [interquartile range=20] years; 50% women), 446 (11%) had NIHSS ≤5. Compared with NIHSS >5, those with NIHSS ≤5 arrived later to the hospital (median, 138 versus 101 minutes), were less likely to receive intravenous alteplase (30% versus 43%), had a longer door-to-puncture time (median, 167 versus 115 minutes) and more likely treated in South Florida (64% versus 53%). In multivariable analysis younger age, private insurance (versus Medicare), history of hypertension, prior independent ambulation and hospital size were independent characteristics associated with NIHSS ≤5. Among EVT patients with NIHSS ≤5, 76% were discharged home/rehabilitation and 64% were able to ambulate independently at discharge as compared with 53% and 32% of patients with NIHSS >5. Symptomatic intracerebral hemorrhage occurred in 4% of mild stroke EVT patients and 6.4% in those with NIHSS >5. Conclusions— Despite lack of evidence-based recommendations, 11% of patients receiving EVT in clinical practice have mild neurological presentations. Individual, hospital and geographic disparities are observed among endovascularly treated patients based on the severity of clinical symptoms. Our data suggest safety and overall favorable outcomes for EVT patients with mild stroke.

Background and Purpose— The impact of transfer status on clinical outcomes in the DAWN (DWI or CTP Assessment With Clinical Mismatch in the Triage of Wake-Up and Late Presenting Strokes Undergoing Neurointervention With Trevo) population is unknown. We analyzed workflow and clinical outcome differences between direct versus transfer patients in the DAWN population. Methods— The following time metrics were analyzed for each group: (1) last known well to hospital arrival, (2) hospital arrival to eligibility imaging, (3) hospital arrival to arterial puncture, (4) qualifying imaging to arterial puncture, (5) last known well to arterial puncture, (6) last known well to reperfusion. The primary end point was the rate of functional independence (90-day modified Rankin Scale [mRS] score, 0–2). Using univariate unconditional logistic regression, we calculated odds ratios and 95% CIs for the association between clinically relevant time metrics, transfer status, and functional independence (mRS 0–2). Results— A total of 206 patients were enrolled. Among these, 121 (59%) patients were transferred, and 85 (41%) patients presented directly to a thrombectomy capable center. Median time last seen well to hospital arrival time was similar between the 2 groups (678 versus 696 minutes). The time from hospital arrival to groin puncture was significantly longer in direct patients compared with transferred patients 140 minutes (interquartile range, 105.5–177.5 minutes) and 88 minutes (interquartile range, 55–125 minutes), respectively ( P P =0.817). Conclusions— Although transfer patients had a faster door to puncture time, benefits of thrombectomy, and rates of mRS 0 to 2 in the treatment group were similar between direct and transferred patients in the DAWN population. These results may inform prehospital and primary stroke centers triage protocols in patients presenting in the late time window. Clinical Trial Registration— URL: https://www.clinicaltrials.gov . Unique identifier: NCT02142283.

Background and Purpose— To evaluate the safety and effectiveness of the Surpass Flow Diverter (Surpass; Stryker Neurovascular, Fremont, CA) in the treatment of large or giant wide-neck intracranial aneurysms at one year, we hypothesize that treatment with Surpass meets or improves on historical safety and efficacy end points. Methods— SCENT trial (Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide Neck Aneurysms) is a multicenter, prospective, single-arm, nonrandomized, interventional trial of the Surpass Flow Diverter for uncoilable or previously treated but failed aneurysms of the intracranial internal carotid artery extending from the petrous segment to the carotid terminus at its bifurcation into anterior and middle cerebral arteries. For enrollment in SCENT, target aneurysms had to be wide-neck (≥4 mm) and large or giant size (≥10 mm). Study results are compared with performance goals derived from a thorough review of the medical literature. The primary effectiveness end point included 3 components: complete aneurysm occlusion, absence of significant parent artery stenosis (≥50%), and no retreatment at 12 months. The primary safety end point was major ipsilateral stroke (increase in National Institutes of Health Stroke Scale score of ≥4) or neurological death within 12 months. Results— At 26 medical centers, 180 patients with 180 target aneurysms were enrolled in the modified intention-to-treat cohort. Per angiographic core lab assessment, there were 15 (8.3%) fusiform, 164 (91.1%) saccular aneurysms, and 1 (0.6%) blister aneurysm. Mean aneurysm size was 12.0 mm. Thirteen (7.4%) aneurysms were giant (≥25 mm). Fifty-eight (32.2%) aneurysms were located in the supraclinoid and distal (including posterior communicating artery) segments of the internal carotid artery. Mean procedure duration was 53.6 minutes. The device was successfully implanted in 97.8% of patients with a mean of 1.1 devices per patient. SCENT met both primary safety and effectiveness end points: 12-month primary effectiveness rate was 62.8% [(113/180); 95% CI, 55.3–69.9] and 12-month major ipsilateral stroke or neurological death rate was 8.3% [(15/180); 95% CI, 4.7–13.4]. Conclusions— Surpass provides safe and effective flow diversion of large or giant, wide-neck, intracranial internal carotid artery aneurysms. Clinical Trial Registration— URL: https://www.clinicaltrials.gov . Unique identifier: NCT01716117.

Introduction: Intracranial atherosclerotic disease (ICAD) is a common cause of refractory stroke. Randomized clinical trials failed to prove the safety and efficacy of the endovascular treatment options of symptomatic ICAD (sICAD). However, there are many concerns regarding inclusion criteria in these trials which made them less effective than standard medical management. Herein, we aim to study the safety and efficacy of drug-eluting balloon mounted stents (DES) in the treatment of sICAD. Methods: A retrospective review of endovascular database from 10 comprehensive stroke centers inside and outside the USA from January 2017 to January 2020 was reviewed. Patients were included if they had symptomatic intracranial stenosis ≥70% in the target vessel, failed best medical management, and underwent intracranial stenting with DES. The primary outcome was the occurrence of ischemic stroke, hemorrhage, or mortality within 72 hours of the procedure. Secondary outcomes included rates of symptomatic and angiographic recurrence within 6 months of the procedure. Results: There was a total of 129 patients, the median age was 65 [58-72] years, 40 (31%) were females. The intracranial stenotic lesions were located in anterior circulation in 74 (57.4%) of cases [24 (18.6%) supraclinoid ICA, 5 (3.9%) cavernous ICA, 17 (13.2%) petrous ICA, 5 (19.4%) MCA-M1, and 3 (2.3%) M2] and in posterior circulation in 55 (42.6%) of cases [36 (27.9) vertebral artery V4 segment, 18 (14%) basilar and 1 (0.7%) PCA]. Recurrent stroke was the qualifying event in 101 (78.3%) while transient ischemic attacks (TIA) were identified in 28 (21.7%) of cases. The median time from the qualifying event to stenting was 6 [2-24] days. Strokes were reported within 72 hours of the procedure; 2 (1.6%) ischemic, 2 (1.6%) hemorrhagic strokes and 2 (1.6%) patients suffered inpatient mortality. The median follow-up time was 6 [3-6.75] months. Among 99 patients who had clinical follow up 2 (2%) had TIA and 6 (6.1%) had strokes. Fifty-one patients had follow-up imaging of whom symptomatic ISR was reported in 8 (15.7%). Conclusion: Our study has shown that in appropriately selected patients with sICAD, endovascular treatment using DES is safe and effective. Prospective randomized clinical trials are warranted.

Introduction: Large Vessel Occlusion (LVO) prediction scales are used to triage prehospital suspected stroke patients with a high probability of LVO stroke to endovascular therapy centers. The sensitivities of these scales in the 6 to 24 hour window are unknown. Higher scale score thresholds are typically less sensitive and more specific. Knowing the highest scale score thresholds that remain sensitive could inform threshold selection for clinical use. Sensitivities may also vary between left and right sided LVOs. Methods: LVO prediction scale scores were retrospectively calculated using the NIHSS sub-item scores of patients enrolled in the DAWN Trial. All patients had last known well times between 6 to 24 hours, NIHSS scores ≥ 10, intracranial ICA or proximal MCA occlusions, and mismatches between their exam severities and infarct core volumes. Scale thresholds with sensitivities ≥ 85% were identified. Scores ≥ 5% more sensitive for left or right sided LVOs were identified. Specificities could not be calculated because all DAWN Trial patients had LVOs. Results: 201 out of 206 patients had the required NIHSS sub-item scores. The highest score thresholds that maintained sensitivities ≥ 85% are bolded in the table. Conclusions: CPSS = 3, C-STAT ≥ 2, FAST-ED ≥ 4, G-FAST ≥ 3, RACE ≥ 5, and SAVE ≥ 3 are likely the highest thresholds that can be selected for extended window LVO triage without missing more than 15% of DAWN Trial eligible LVO strokes. For CPSS and SAVE, these are higher than the thresholds suggested by prior studies. CPSS = 3 and RACE ≥ 5 were more sensitive for right sided LVOs. These findings represent the maximum anticipated sensitivities of LVO prediction scales since the NIHSS scores were documented in hospitals during a clinical trial rather than in the prehospital setting. Inclusion of lower NIHSS or more distal LVO patients would lower sensitivities further. Selecting even higher scale thresholds for LVO triage would lead to many missed LVO strokes.

Background: Access to endovascular therapy (EVT) should be equitable to all eligible ischemic stroke patients presenting within the treatment time window. In the Florida Stroke Registry (FSR) we sought to determine sex, race/ethnic, hospital and regional disparities in the delivery of EVT. Methods: From January 2010 to January 2020, a total of 99,088 ischemic stroke cases within 24 hours of symptom onset were enrolled. Multivariable logistic regression with generalized estimating equations evaluated independent predictors of EVT utilization. Results: A total of 7,812 patients received EVT (51.2% female, mean age 71.3 ± SD 14.6 years, 61.4% white, 17.4% black, 21.2% Hispanic). Compared to those not treated, EVT treated patients were more likely Hispanic (21.2% vs. 14.6%), arrived earlier to the hospital (median 120 min (IQR 292) vs. 170 min (IQR 446)), via EMS (94% vs. 66%), with more severe strokes (median NIHSS 15 (IQR11) vs. 5 (IQR 9)), to large hospitals (≥ 680 beds) (73.4% vs. 47.7%), in South Florida (50.8% vs. 38.2%). In multivariable analysis, female sex (OR 1.05, 95% CI 1-1.11), atrial fibrillation (OR 1.57, 95% CI 1.45-1.7), higher NIHSS (> 6) (OR 6.19, 95% CI 5.11-7.51) and presenting to a high-volume hospital (OR 3.47, 95% CI 2.25-5.36) positively predicted EVT utilization, whereas older age (>80 years) (OR 0.88, 95% CI 0.80-0.96), and black race (vs. white OR 0.87, 95% CI 0.76-1), were independently associated with lower use of EVT. Conclusions: In this large state-wide registry study, we found significant race-ethic and geographical disparities in delivery of EVT. Systems of care should address disparities in stroke treatment to improve access to EVT for all eligible stroke patients.

Introduction: Red blood cell (RBC) rich vs fibrin rich clots have different mechanical properties and greater knowledge about clot composition in the context of clinical, imaging, and procedural factors in mechanical thrombectomy (MT) may help with procedural optimization. The EXCELLENT Registry (NCT03685578) is a prospective, global, multi-center, observational registry of EmboTrap as the first line MT device for large vessel occlusion (LVO). We present an interim analysis of clot collected per pass in the registry. Methods: Five hundred thirty-three clot specimens from 376 subjects were collected by 20 sites and sent for analysis by independent Central Labs under standardized protocol. Analysis was interrupted by COVID-19, but the labs were fully operational as of June 2020 and on track to deliver results for 300 subjects in Q4. At the time of abstract submission, composition data for 234 clots from 163 subjects was available. All available data will be presented at the time of the conference. Results: Cardioembolic etiology (n=100) was associated with lower RBC (40.2 vs 47.2%) and higher fibrin content (31.7 vs 26.7%) compared to large artery disease (n=12). Hyperdense/vessel susceptibility sign (78+, 24-, per independent imaging core lab) corresponded to higher mean RBC content (44.4 vs 34.9%). Treatment with IV tPA (60+, 91-) had no clear impact on clot composition (42.3 vs 40.6% RBC; 30.4 vs 30.0% fibrin). Notably, clots retrieved with the first 2 passes of were more RBC rich (42.1 vs 28.0%) and clots retrieved in higher passes had a higher average fibrin content (35.5 vs 29.6%) suggesting that higher fibrin content leads to greater refractoriness. Conclusions: Clot density/susceptibility on baseline imaging, stroke etiology and number of thrombectomy passes were associated with differential clot composition. These findings may have potential implications for the development of better MT strategies.

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.

Background: The Florida Stroke Act set criteria for comprehensive stroke centers (CSC). Hospitals could be certified by a national agency (The Joint Commission (TJC), Det Norske Veritas (DNV), Healthcare Facilities Accreditation Program (HFAP)) or could self-attest as fulfilling CSC criteria. This study aimed to evaluate whether nationally certified (NC) and self-attested hospitals (SA) have similar quality of care in acute ischemic stroke (AIS). Methods: The study population included AIS cases from 37 CSCs (74% of FL CSCs) in the FL-Stroke Registry, a multi-hospital registry using Get With the Guidelines-Stroke data from Jan 2013-Dec 2018. Hospital and patient level characteristics and stroke metrics were evaluated using unadjusted and adjusted (age, sex, race and NIH) analyses. Results: 13 NC-CSCs with 32,061 AIS cases and 24 SA-CSCs with 46,363 AIS cases were included. NCs were larger, with younger patients (71 (60-81) vs 72 (61-82)) and more severe strokes (median NIH; 5 vs 4, NIH ≥ 16; 15.4 vs 11.9% p p p p p p =.01). Conclusion: Among FL-Stroke Registry CSCs, AIS performance and treatment measures are superior in NC CSC when compared to SA CSCs. These findings have crucial implications for stroke systems of care in Florida and supported recent change in legislation regarding CSC center certification.

Background: We performed a multicenter prospective clinical registry across 11 centers to study the association between histopathological characteristics of retrieved clots and imaging, stroke etiology and clinical outcomes. Materials and Methods: Following IRB approval at the 11 centers, patients were enrolled in the STRIP registry. All retrieved emboli were sent for histopathological analysis with H&E and MSB staining. Demographic variables, comorbidities, stroke etiology, imaging findings and procedural details were collected for each case. We studied the association between clot histopathology and imaging findings, stroke etiology and and revascularization outcomes. Student’s t-test was used for continuous variables and chi-squared testing for categorical variables. Results: To date, 1022 patients have been included. There was a significant correlation between platelet rich clots and the absence of hyperdensity on non-contrast CT [p=0.321, p=0.003) and a significant inverse correlation between the percentage of platelets and mean HU on NCCT (p=-0.243, p=0.025). The proportion of platelet-rich clots (55.0% versus 21.2%, p=0.005) and the percentage of platelet content (22.1% versus 13.9%, p=0.03) was significantly higher in patient with large artery atherosclerosis compared to those with a cardioembolic etiology. There was no correlation between RBC density, WBC density, fibrin density or platelet density and revascularization outcomes with stent-retrievers. However, we have found that with aspiration alone, patients with platelet rich clots are less likely to be fully revascularized (i.e. TICI 2c/3) than non-platelet rich clots (OR=0.36, 95%CI=0.12-0.81, P Conclusions: Interim analysis of the STRIP registry suggests that the platelet content of a clot may be the most revealing factor in determining a clot’s etiology, imaging features and revascularization outcome. Platelet rich clots are less dense on NCCT, are associated with a large artery atherosclerosis source and are less likely to be completely revascularized with aspiration alone.

Introduction: It is unclear whether the outcomes of late presenting patients (6-24 hrs from symptom onset) receiving endovascular thrombectomy (EVT) in routine clinical practice parallels the favorable results of recently completed randomized trials. We evaluated characteristics and outcomes of EVT utilization, over the past decade, for late and early presenting (≤ 6 hrs from onset) patients. Methods: From Jan 2010 to Jan 2019, 84,346 ischemic stroke patients presenting within 24 hrs of symptoms were enrolled in the Florida Stroke Registry. Differences in clinical characteristics, utilization trends and outcomes at discharge were compared between late vs. early presenting EVT patients using multivariable regression analysis. Results: Among 5,702 EVT patients (mean age 71±15, 48% women), 1,580 (28%) were late presenting. Late presenting EVT patients had higher rates of private insurance (39% vs 35%), dyslipidemia (39% vs 35%) and smoking (16% vs.13% ) but lower rates of Hispanic patients (19% vs 24%) and atrial fibrillation (34% vs 37%.). Late presenting patients had lower National Institute of Health Stroke Scores [median 14 (IQR=12) vs 17 (IQR=11)] and rates of thrombolysis (6% vs 58%). Short term discharge outcomes and treatment complications are shown in Table. In multivariable analysis adjusting for age, sex, stroke severity and intravenous thrombolysis, late presenting EVT patients had similar symptomatic intracerebral hemorrhage rates [OR 1.02 (0.72-1.45)] and outcomes but were less likely to ambulate independently at discharge (OR 0.80, 95% CI 0.70-0.92) compared to early presenting EVT patients. Discussion: Over the past decade, nearly a third of EVT patients were treated after 6 hours from onset. In clinical practice late EVT carries comparable safety and favorable outcome profiles to early EVT.

Background The Pipeline Flex (PED Flex; Medtronic, Dublin, Ireland) was designed to facilitate deployment and navigation compared to its previous iteration to reduce the rate of technical events and complications. Objective To assess the neurological morbidity and mortality rates of the PED Flex at 30 d. Methods Information from 9 neurovascular centers was retrospectively obtained between July 2014 and March 2016. Data included patient/aneurysm characteristics, periprocedural events, clinical, and angiographic outcomes. Multivariate logistic regression was performed to determine predictors of unfavorable clinical outcome (modified Rankin Scale [mRS] > 2). Results A total of 205 patients harboring 223 aneurysms were analyzed. The 30-d neurological morbidity and mortality rates were 1.9% (4/205) and 0.5% (1/205), respectively. The rate of intraprocedural events without neurological morbidity was 6.8% (14/205), consisting of intraprocedural ischemic events in 9 patients (4.5%) and hemorrhage in 5 (2.4%). Other technical events included difficulty capturing the delivery wire in 1 case (0.5%) and device migration after deployment in another case (0.5%). Favorable clinical outcome (mRS 0-2) was achieved in 186 patients (94.4%) at discharge and in 140 patients (94.5%) at 30 d. We did not find predictors of clinical outcomes on multivariate analysis. Conclusion The 30-d rates of neurological morbidity and mortality in this multicenter cohort using the PED Flex for the treatment of intracranial aneurysms were low, 1.9% (4/205) and 0.5% (1/205), respectively. In addition, technical events related to device deployment were also low, most likely due to the latest modifications in the delivery system.

Background Middle meningeal artery (MMA) embolization has emerged as a promising treatment for chronic subdural hematoma (cSDH). Objective To determine the safety and efficacy of MMA embolization. Methods Consecutive patients who underwent MMA embolization for cSDH (primary treatment or recurrence after conventional surgery) at 15 centers were included. Clinical details and follow-up were collected prospectively. Primary clinical and radiographic outcomes were the proportion of patients requiring additional surgical treatment within 90 d after index treatment and proportion with > 50% cSDH thickness reduction on follow-up computed tomography imaging within 90 d. National Institute of Health Stroke Scale and modified Rankin Scale were also clinical outcomes. Results A total of 138 patients were included (mean age: 69.8, 29% female). A total of 15 patients underwent bilateral interventions for 154 total embolizations (66.7% primary treatment). At presentation, 30.4% and 23.9% of patients were on antiplatelet and anticoagulation therapy, respectively. Median admission cSDH thickness was 14 mm. A total of 46.1% of embolizations were performed under general anesthesia, and 97.4% of procedures were successfully completed. A total of 70.2% of embolizations used particles, and 25.3% used liquid embolics with no significant outcome difference between embolization materials (P > .05). On last follow-up (mean 94.9 d), median cSDH thickness was 4 mm (71% median thickness reduction). A total of 70.8% of patients had >50% improvement on imaging (31.9% improved clinically), and 9 patients (6.5%) required further cSDH treatment. There were 16 complications with 9 (6.5%) because of continued hematoma expansion. Mortality rate was 4.4%, mostly unrelated to the index procedure but because of underlying comorbidities. Conclusion MMA embolization may provide a safe and efficacious minimally invasive alternative to conventional surgical techniques.

Introduction: Clot burden score (CBS) is developed to evaluate anterior circulation ischemic stroke thrombus extent. Lower CBS is associated with worse functional outcome in an analysis of MR CLEAN trial without modifying the effect of mechanical thrombectomy within 6 hours after symptoms onset. An analysis of SWIFT PRIME trial showed that stent-retriever thrombectomy successfully recanalize regardless of CBS. However, thrombus that remains stagnant for longer period may be further compressed by the water-hammer effect of the systolic blood pressure, resulting in removal difficulty. We aim to explore relation of CBS with mechanical thrombectomy (MT) in the extended 6-24 hours of the DAWN trial. Method: A blinded assessor evaluated CBS in all patients receiving CTA brain in the multicenter randomized DAWN trial for MT in acute large vessel occlusion last known well 6-24 hours (DWI or CTP Assessment with Clinical Mismatch in the Triage of Wake up and Late Presenting Strokes Undergoing Neurointervention). The cohort was divided into low CBS (0-4) and high CBS (5-10) groups. We used ordinal logistic regression for analysis of association with good outcome (mRS≤2), adjusted for significant baseline variables. Results: 143 patients were included. Low CBS group consisted of 50 patients (29 received MT and 21 received medical management). High CBS group consisted of 93 patients (44 received MT and 49 received medical management). Baseline demographics were similar between groups. Low CBS group showed no difference in the odd of good outcome, adjusted OR 0.58 (0.3-1.14). Analysis of MT cases, Low CBS group showed a strong trend to higher procedure time (81.5±55.2 versus 56.4±35.3 min, p=0.07). There was no association of Low CBS and odds of good outcome (OR 0.9; 0.27-2.92), successful recanalization (OR 0.58; 0.18-1.89), and symptomatic intracranial hemorrhage (OR 1.67, 0.55-5.09). Conclusion: Despite literature reporting worse outcome of anterior circulation ischemic stroke with low CBS, acute large vessel occlusion stroke with last known well 6-24 hours and low CBS treated with thrombectomy was feasible and not associated with worsen outcome compared to high CBS. However, a strong trend to higher procedure time is observed.

Background and Purpose: There is disparity on neuroimaging selection for acute stroke thrombectomy. Patients with large core infarcts are often excluded from reperfusion therapies. We aim to assess rates of favorable clinical outcomes in patients with large cores based on CTP (RAPID) and the effect of collaterals in this population. Methods: Retrospective study of patients with ischemic cores greater than 50cc on CTP and a proximal anterior circulation occlusion on computed tomographic angiogram who underwent endovascular thrombectomy. Evaluation period was October 2015 to June 2018 on three comprehensive stroke centers. Baseline characteristics, ASPECTS and collaterals scores were evaluated. Primary endpoint was rate of favorable clinical outcome at 3 months. Results: 45 patients were included in the study. Mean age was 65 ±14.2 years, mean NIHSS score was 20 (10-32) and mean admission infarct volume was 85±31mL (CBF 6 s was 199.5±68mL. The majority of patients presented within 6 hours (82%). Median ASPECTS score was 8 and 33% of patients had a favorable collaterals. Recanalization thrombolysis in cerebral ischemia 2b-3 was 88%. Post-thrombectomy mean infarct volume at 24 to 48 hours was 107±68.3mL, A total of 42% (19/45) had tPA. A 3-month favorable clinical outcome (mRS 0-2) was present in 31% (14/45) of patients. Rate of intracranial hemorrhage (ph1 or ph2) was 11% (5/45). A total of 92% (13/14) of all patients older than 75 years had a poor clinical outcome (mRS score >2). Among patients with good collaterals 46% (7/15) had good clinical outcomes whereas 23% (7/30) of patients with poor collaterals score had good clinical outcomes at 3 months. The rate of good outcome at three months for patients with ASPECTS> 6 was 31% (11/35), while 41% of patients with both favorable ASPECTS and Collaterals had a good clinical outcome. Hemicraniectomy was performed in 4% (2/45) of all patients. Conclusions: Acute stroke thrombectomy may be beneficial in some patients with large core based on CTP with good collaterals and it should not be withhold solely based on the core infarct volume on CTP in patients presenting within 6 hours.

Background: Mechanical thrombectomy in late-presenting stroke patients with a limited infarct core on CTP/DWI is highly effective. We aimed to evaluate the degree of disability at discharge as an indicator for functional impairment at one and three months after mechanical thrombectomy compared to medical management in these patients. Methods: This study concerns a post-hoc analysis of the DAWN-trial population. Patients presenting 6-24h after symptom onset of an emergent large vessel occlusion with mismatch between symptom severity and infarct size on CTP/DWI, were randomized for medical management versus mechanical thrombectomy. We assessed the change in modified Rankin score (mRS) from discharge up to three months post-stroke for DAWN-patients treated with mechanical thrombectomy compared to those randomized to medical management. Kendall’s tau test was used to evaluate the correlation between the mRS at discharge, at 30 days, and at 90 days. Mixed models were used to explore the potential difference between treatment arms in the change of utility weighted mRS over time. Results: Ninety-eight of 107 patients treated with mechanical thrombectomy and 89/99 controls survived at discharge and were included in the analysis. We found a strong correlation between the mRS at discharge, at 30 days, and at 90 days for both treatment arms with a tau varying from 0.52 to 0.72 for mechanical thrombectomy and 0.56 to 0.71 for medical management. All correlation coefficients were statistically significant (p < 0.0001). The utility weighted mRS after mechanical thrombectomy was consistently superior to medical management (p < 0.0001). Although there was a trend towards a stronger dispersion of the utility weighted mRS over time after mechanical thrombectomy, there was no statistically significant interaction effect between time and treatment arm (p 0.44). Conclusion: The treatment effect of mechanical thrombectomy occurs early and further improvement over time is similar to that of medical management. The mRS at discharge is a robust indicator for functional status at one and three months post stroke and may therefore be used as an alternative measure for clinical outcome.

Background and Purpose: In acute stroke therapy, faster reperfusion leads to better outcome. We analyzed optimization steps to reduce treatment delays at a comprehensive stroke center in a non-academic tertiary hospital. Methods: Consecutive patients with ischemic stroke treated with either IV tPA, endovascular therapy or both were analyzed. Patient metrics were divided into two periods: pre-optimization period and post-optimization period. Key interventions of this workflow included: (1) addition of pre notification by EMS to ER and stroke team; (2) dividing stroke alert to level 1 (potential IV/IA candidate) vs. level 2; (3) direct transportation of level 1 stroke patients to brain CT imaging; (4) limitation of non-essential interventions; (5) 24/7 code stroke response by an in house trained vascular midlevel (NP/PA) and vascular neurologist (either in house or through telestroke network);(6) earlier notification of IR team; (7) CT to angiosuite direct transportation for LVO; (8) multidisciplinary monthly meetings to discuss delayed cases. Door to needle time and door to puncture time were used as target metrics in order to measure improvement. Results: A total of 279 patients were identified (101 in the pre-optimization and 178 in the post- optimization periods). No significant differences in any of the patient’s baseline characteristics were documented in the two observation periods. Almost all metrics favored the post-optimization period with a remarkable improvement in door to puncture time (64 (IQR 36-86) vs. 47 (IQR 20-62) min, p=0.002). Although non-statistically significant, we observed an increased percentage of good clinical outcomes in the post-optimization group (60.1% vs 54.8%, p=0.500). Conclusions: For patients undergoing acute reperfusion therapies, significant reductions in workflow time-frames can be achieved after simple optimization steps in a non-academic community based hospital.

Introduction: Surpass™ Flow Diverter was developed to treat large or giant wide-neck intracranial aneurysms (IA) not amenable to surgical or current standard endovascular treatment due to location, morphology, or known treatment challenges. FDA approved on July 13 2018, Surpass™ fulfills an unmet clinical need. Indications for Use allow for placement in the entire intracranial internal carotid artery (ICA). Surpass™ is available in diameters of 3 to 5 mm and lengths of 15 to 50 mm. Methods: SCENT Trial is an international, multi-center, prospective, non-randomized trial comparing the outcomes of Surpass™ Flow Diverter treatment to historical control. It is designed to evaluate the safety and efficacy of Surpass™ for treatment of wide-neck (≥4mm), large or giant IA ≥10 mm in size. The primary safety endpoint is the percent of subjects experiencing neurologic death or major ipsilateral stroke at 12 months. The primary effectiveness endpoint is the percent of subjects with 100% occlusion (Raymond Class 1) without clinically significant stenosis (≤50% stenosis) of the parent artery, and any retreatment of the target aneurysm at 12-month. Results: From 2012 to 2015, 180 subjects were treated at 26 sites. Mean age was 61.0 years and 91.7% (165/180) were females. Aneurysms were most frequently located in the carotid-ophthalmic segment (33.3%; 60/180), followed by the cavernous segment (28.9%; 52/180), posterior communicating artery (21.1%; 38/180), supraclinoid carotid artery (11.1%; 20/180), superior hypophyseal artery (3.3%; 6/180), and the petrous segment (2.2%; 4/180). Mean aneurysm dimension included dome height 13.4±5.7 mm. Mean neck width was 6.7 mm. Technical success occurred in 97.8% (176/180) of subjects while the mean number of Surpass™ devices used was 1.1 per procedure, with 86.7% (156/180) of aneurysms treated with a single flow diverter. The 12-month primary effectiveness rate was 62.8% [(113/180), 95% CI 55.3, 69.9] and 12-month major ipsilateral stroke or neurological death rate of 10.6% [(19/180), 95% CI 55.3, 69.9] Conclusions: Surpass™ Flow Diverter is safe and effective to treat large and giant aneurysms intracranial internal carotid aneurysms.

Background and Purpose: Acute ischemic stroke secondary to tandem occlusions or carotid stenosis alone present treatment challenges, especially when antiplatet therapy is needed for extracranial or intracranial stenting.. To date, there is no standardized approach for antiplatelet inhibition in this acute setting. Methods: A single-arm pilot study was performed to assess the safety and efficacy of cangrelor plus aspirin in neurointervention for platelet inhibition in patients who require acute stenting in the setting of ischemic stroke. A standard institution protocol was generated which included 15mcg/kg loading dose followed by 2.0mcg/kg/min infusion. Once post op imaging excluded hemorrhage this was converted to aspirin and brilinta and cangrelor was discontinued. Results: A total of 6 patients have been enrolled from October 2017 to July 2018. The median age was 73 years (57.5 - 85.3). At admission, the median NIHSS was 12.5 (2 - 22.3). All of the patients were treated in acute setting per the stroke protocol at our institution. Cangrelor was infusedand all patient achieved an adequate platelet inhibition (< 200 PRU (P2Y12 Reaction Units)). Five out 6 cases, had a proximal carotid stent placed and 1 patient underwent intracranial MCA stenting. None of the patients experienced periprocedural hemorrhagic or thromboembolic complications. There was also no in-stent thrombosis within 24 hours after the intervention. The majority of patients (4/6) had a good clinical outcome at discharge (mRS 0-2). Conclusions: Our findings suggest that Cangrelor is a promising alternative in acute stenting for the treatment of cerebrovascular pathology, however, further studies with larger samples are required to accurately elucidate its safety and effectiveness in neuroendovascular procedures.

Vascular access for cerebral angiography has traditionally been performed via the common femoral artery. It is crucial to obtain safe access to prevent complications that could lead to limb ischemia, groin hematoma, or retroperitoneal hematoma. This is especially true in neurointervention as many patients are anticoagulated or have received intravenous thrombolytics prior to their intervention. Special attention to anatomic landmarks, both grossly and radiographically, can help to assure safe access. The patient consented for this procedure. This video details rapid but safe femoral artery access in a patient undergoing emergent thrombectomy.

Background and Objective: The optimal management of intracranial arterial stenosis is unclear, particularly in patients who have failed medical management. We report a multicenter real-world experience of endovascular recanalization of intracranial atherosclerotic stenosis refractory to aggressive medical therapy. Methods: Retrospective multicenter case series of consecutive endovascularly treated patients presenting with symptomatic (TIA or stroke) who had failed medical therapy were identified. All of the patients were considered to be at high risk with unstable symptomatic intracranial stenosis and progression or recurrence of symptoms despite the best medical management and underwent endovascular intervention either with stenting and/or balloon angioplasty. Results: 98 patients presented with recurrent TIAs (n= 40) or recurrent or progressive strokes (n= 58) and were treated in 8 stroke centers from 2009 to 2017. All patients were treated either with dual antiplatelet therapy (84%) or anticoagulation and all had statin therapy prior to recurrence or progression of their symptoms. There was one periprocedural perforation resulting in patient death. There were 3 patients who had periprocedural strokes and 2 patients had symptomatic intraparenchymal hemorrhage with a total of four (4%) periprocedural mortality. The all-cause mortality rate at discharge was 6%. At 90-day follow-up, 7 (10%) patients had TIAs and 2 (3%) patients had ipsilateral strokes, and 78% of patients had mRS of 2 or less. Conclusion: Endovascular recanalization of unstable intracranial atherosclerotic stenosis who have failed medical therapy is feasible and safe.

Background: Collaterals govern the pace and severity of cerebral ischemia, distinguishing fast or slow progressors and corresponding therapeutic opportunities. The fate of sustained collateral perfusion or collateral failure is poorly characterized without arterial revascularization. We characterized the nature and impact of collaterals in the late time window for thrombectomy established in DAWN. Methods: The DAWN Imaging Core Lab prospectively scored collateral grade on baseline CTA and DSA (endovascular arm only), blinded to all other data. CTA collaterals were graded with the Tan scale and DSA collaterals were scored by ASITN grade. Descriptive statistics characterized CTA collateral grade in all DAWN subjects and DSA collaterals in the endovascular arm. The relationship between collateral grade and day 90 outcomes was separately analyzed for each treatment arm. Results: Collateral circulation to the ischemic territory was evaluated on CTA (n=144; median 2, 0-3) and DSA (n=57; median 2, 1-4) before thrombectomy in 161 DAWN subjects (mean age 69.8 ± 13.6 years; 55.3% women; 91 endovascular therapy, 70 control). CTA revealed a broad range of collaterals (grade 3=100%, n=64; 2=50-99%, n=45; 1=0-49%, n=31; 0=0%, n=4). DSA also showed a diverse range of collateral grades (grade 4, n=4; 3, n=22; 2, n=27; 1, n=4). Across treatment arms, baseline demographics, clinical variables except AF (41.6% endovascular vs. 25.0%, p=0.04) and CTA collateral grades were balanced. More robust CTA collateral grade was linked with lower baseline NIHSS (r=-0.25; p=0.003), smaller core infarct volumes (r=-0.36, p Conclusions: DAWN subjects enrolled at 6-24 hours after onset with small infarct cores had a wide range of collateral grades on both CTA and DSA. In this late time window, better collaterals manifest milder stroke severity at baseline, smaller infarct cores and better clinical outcomes.

Introduction: It is well-established that, within 0-6 hours, the benefit of thrombectomy rapidly decays over time. The DAWN trial demonstrated that, in the presence of clinical-core mismatch (CCM), thrombectomy remains beneficial within 6-24 hours. We aim to assess the effect of time to randomization on outcomes in the DAWN. Methods: We used traditional multivariate logistic regression controlling age and NIHSS at baseline adding an interaction between Trevo and Time last seen well and then generated the odds ratio of the interaction of Trevo and time at particular time points. Results: Each 1-hour delay to treatment markedly impacted functional independence (OR,0.89 [95% CI 0.75 to 1.03]). Although the odds of functional independence at 90 days (mRS 0-2) with thrombectomy declined with longer time from last seen well (TLSW) to puncture, treatment benefit was observed through 24 hours : cOR at 8 hours, 6.8 (95% CI, 2.1 to 22.0), absolute risk difference (ARD) for mRS 0-2, 24.4%; cOR at 12 hours, 9.4 (95% CI, 4.1 to 21.6), ARD, 35.1%; cOR at 16 hours, 13.0 (95% CI, 4.1 to 41.3), ARD, 37.2%; cOR at 20 hours, 17.8 (95% CI, 2.9 to 110.4), ARD, 36.5%; cOR at 24 hours, 24.6 (95% CI, 1.9 to 322), ARD, 35.5% (Figure). Comparable analysis using time from symptoms first observed (TSFO) yielded similar results. Conclusion: In patients selected based on CCM, treatment benefit persists all the way to 24 hours; however, both the chances of good outcome and the overall treatment effect continuously drop over time.

Background and Objective: Use of Computed Tomographic Perfusion (CTP) imaging at a referring hospital may help triage and shorten door-to-puncture time for patients with acute ischemic stroke. Methods: We conducted a single center retrospective review of a prospectively maintained database of consecutive ischemic stroke patients transferred to our center for consideration of endovascular therapy. Patients were divided into two groups. Group 1 consisted of patients transferred from a facility where CTP (using automated RAPID software) was routinely performed and group 2 consisted of patients transferred from a facility that did not perform perfusion imaging. Results: We identified a total of 132 patients all of whom were transferred to our center from April of 2014 to April of 2017. There were no differences in baseline characteristics between two groups. A total of 34 patients were transferred from a facility with RAPID CTP (Group 1) and 98 were transferred from a facility with no CTP (Group 2). Door-to-puncture time was significantly lower for patients in Group 1 compared with Group 2 (median [IQR], 12 [8 - 16] minutes and 48.5 [32.8 - 71.8] minutes, p Conclusions: We found that triaging from a primary stroke center with CTP ability significantly reduced door-to-puncture time as compared with transferred patients with no perfusion imaging without any significant delay in transfer process.

Background: Patients with minor ischemic stroke were largely excluded from the randomized trials of endovascular therapy (EVT) in stroke. In the Florida-Puerto Rico Registry we sought to determine the utilization of EVT in this population. Methods: From January 2010 to March 2017, 57,750 acute ischemic stroke patients within 24 hours of symptom onset were prospectively included from 88 sites in four Florida regions (south, west central, north and panhandle, east central) and Puerto Rico. Differences between minor (NIHSS ≤ 5) and moderate/severe (NIHSS>5) stroke patients who received EVT were evaluated using multivariable logistic regression with generalized estimating equations. Results: Among 2,845 EVT patients (50% women, mean age ±SD 71±14 years), 347 (12%) had NIHSS ≤ 5. As compared to NIHSS>5, minor stroke patients were younger (mean age 67 vs. 71, p5. Majority of minor stroke patients who received EVT were discharged home or to rehab (75%) while 53% of those with NIHSS>5. Conclusions: More than 1 in 10 cases that received EVT had mild neurological symptoms. Many factors including hospital expertise and time of presentation affect the use of this treatment. Further study of EVT in minor stroke is warranted.

Background: The impact of baseline ischemia on Aspects and evolution over 24 hours may be distinct in the late thrombectomy time window recently established by dawn. Aspects may enable practical triage of thrombectomy candidates more than 6 hours after onset. Methods: The dawn Imaging Core Lab independently scored Aspects at baseline and 24 hours. Descriptive statistics characterized Aspects on CT or MRI at baseline and 24 hours, delineating serial ASPECTS change or infarct evolution over 24 hours and analyzing associations with clinical variables, treatment arm and clinical outcomes. Results: 193 DAWN subjects (mean age 70.2 ± 13.7 yrs; 56% female; baseline NIHSS median 17 (14, 21) had core lab adjudicated Aspects at both baseline and 24 hours. Baseline Aspects was median 8.0 (3-10), with 89/193 (46.1%) between 0-7 and 104/193 (53.9%) between 8-10. 24-hour ASPECTS was median 6.0 (0-9), with serial ASPECTS change or infarct evolution of median -1, ranging from -8 to 0. Multivariate logistic regression showed age (OR 1.03 (yr) 95%CI (1.01-1.05), p=0.011) and male sex (OR 0.51 95%CI (0.30-0.86), p=0.012) predicted higher baseline ASPECTS. Higher 24-hour ASPECTS was predicted by endovascular treatment (OR 2.42 95%CI (1.42-4.12), p=0.001), baseline glucose < 150 mg/dL (OR 2.23 95%CI (1.19-4.18), p=0.012), lower baseline NIHSS (OR 0.92 95%CI (0.88-0.97), p=0.003) and age (OR 1.03 (yr) 95%CI (1.01-1.05), p=0.002). Good clinical outcome (day 90 mRS 0-2) was predicted by 24-hour ASPECTS (OR 1.50 95%CI (1.22-1.85), p Conclusions: DAWN subjects enrolled with small infarct cores in the late time window had a broad range of baseline ASPECTS. 24-hour ASPECTS, strikingly influenced by endovascular therapy, predicted good clinical outcomes. Infarct evolution on serial ASPECTS provides robust biomarker data for endovascular therapy up to 24 hours from onset.

BACKGROUND Recent studies have highlighted the obesity paradox where patients with obesity have a greater chance of survival than patients with normal weight. OBJECTIVE To investigate the association between body mass index (BMI) and age with severity of subarachnoid hemorrhage (SAH) and functional outcome. METHODS We retrospectively reviewed the charts of 274 consecutive patients admitted with SAH between June 2008 and June 2012. Data collected included patient demographic features (age, sex, BMI), severity of SAH at admission (Fisher grade, Hunt and Hess grade, Glasgow Coma Scale score, and the World Federation of Neurosurgeons Scale score), as well as functional outcome measured by the modified Rankin Scale (mRS) by death or discharge. RESULTS The median age was 57 years (range, 18-99), and 62% were female; the median BMI was 27 (range, 14.3-55.1). On multivariate analysis adjusting for age and sex, there was no evidence of an association between BMI and Hunt and Hess grade, Fisher grade, World Federation of Neurosurgeons Scale score, Glasgow Coma Scale score, or mRS score (all P≥.17). On multivariate analysis adjusting for BMI and sex, there was evidence of a higher mRS score (P

Introduction: An evolution in endovascular approaches has been observed in the last decade with stent retrievers (ST) being the latest generation of devices. Stent retriever thrombectomy and manual aspiration (MAT) have each shown to lead to high rates of recanalization as single modality endovascular stroke therapy. We aimed to compare clinical outcomes, efficacy and safety of ‘stent retriever mediated manual aspiration thrombectomy’ and manual aspiration thrombectomy (MAT) alone. Methods: 145 patients with M1 vessel circulation stroke and had undergone thrombectomy treatment were identified between March 2014 and June 2016 in two high volume centers. The patient’s data were retrospectively analyzed to evaluate the technical characteristics, angiographic outcome (Thrombolysis In Cerebral Infarct - TICI score) and clinical outcome at discharge (NIHSS and mRS) Results: 69 patients were treated with ST (Solitaire and Trevo) and 76 with MAT. IV-TPA was administered in 37.4% of cases. Effective recanalization, TICI grades 2b/3, was achieved in 84.1% of cases treated with ST and in 89.5% treated with aspiration with no statistical significance between the two techniques. Symptomatic cerebral hemorrhage was found in 4.3% of the cases. Favorable outcome defined as a mRS of 0-2 at discharge was found in 38% of cases with higher rates in the group treated with ST (56.1% vs 33.3%; p 0.01). Conclusion: Stent retriever mediated manual aspiration thrombectomy is a safe and efficacious method of achieving high revascularization rates for M1 vessel occlusion with improved outcomes at discharge.

BACKGROUND: The majority of moyamoya surgical series have been confined to Asian and pediatric populations. Few have studied demographics, risk factors, and outcomes in adult North American populations. OBJECTIVE: To examine outcomes after revascularization for moyamoya in white and African American adults and to assess for predictors of recurrent stroke. METHODS: A retrospective review of 75 non-Asian patients undergoing 110 procedures at the Mayo Clinic was performed. Demographics, known moyamoya associations, cerebrovascular risk factors, and autoimmune diseases were recorded. Primary outcomes for vascular events were assessed with Kaplan-Meier analysis. Fisher exact methods were used to evaluate for associations with recurrent events. RESULTS: Mean age was 42 years, and mean follow-up was 47 months. Seventy-one of the 75 patients were white. The majority had bilateral disease (n = 49). Perioperative ischemic events occurred in 5 patients (4.5%). The 5- and 10-year event rates were 5.8% and 9.9%. Significant associations were found with a history of thyroid disease (P = .05) and recurrent stroke. A trend was also found between hypertension and autoimmune disease with recurrent stroke. CONCLUSION: Outcomes were favorable with revascularization in this subset with moyamoya. A significant association between a history of thyroid disease and recurrent stroke was found. Additionally, high prevalences of autoimmune disease, hypertension, and thyroid disease were found in our cohort, suggesting that they may play a role in the pathophysiology and progression of moyamoya disease in this population. A new classification for moyamoya is proposed based on these data.

Background: The promising results of the Solitaire Flow Restoration (FR) With the Intention for Thrombectomy (SWIFT) trial recently led to Food and Drug Administration (FDA) approval of the Solitaire FR stent retriever device for recanalization of cerebral vessels in patients with acute ischemic stroke. Objective: To report the early postmarket experience with this device since its FDA approval in the United States, which has not been previously described. Methods: We conducted a retrospective analysis of consecutive acute ischemic strokes cases treated between March 2012 and July 2012 at 10 United States centers where the Solitaire FR was used as a single device or in conjunction with other intraarterial endovascular approaches. Results: A total of 101 patients were identified (mean age, 64.7 years; mean admission National Institutes of Health Stroke Scale [NIHSS] score, 17.6). Intravenous thrombolysis was administered in 39% of cases; other endovascular techniques were utilized in conjunction with the Solitaire FR in 52%. Successful recanalization (Thrombolysis in Myocardial Infarction 2/3) was achieved in 88%. The rate of symptomatic intracranial hemorrhage within the first 24 hours was 15%. In-hospital mortality was 26%. At 30 days, 38% of patients had favorable functional outcome (modified Rankin scale score ≤2). Severity of NIHSS score on admission was a strong predictor of poor outcome. Conclusion: Our study shows that a variety of other endovascular approaches are used in conjunction with Solitaire FR in actual practice in the United States. Early postmarket results suggest that Solitaire FR is an effective tool for endovascular treatment of acute ischemic stroke.

Background The external carotid artery (ECA) anastomoses in many distal territories supplied by the internal carotid artery (ICA) and is an important source of collateral circulation to the brain. Stenosis of the ECA in ipsilateral ICA occlusion can produce ischemic sequelae. Objective To examine the effectiveness of ECA stenting in treating symptomatic ipsilateral ICA occlusion. Methods We retrospectively reviewed patient databases from 5 academic medical centers to identify all individuals who underwent ECA stenting after 1998. For all discovered cases, coinvestigators used a common submission form to harvest relevant demographic information, clinical data, procedural details, and follow-up results for further analysis. Results Twelve patients (median age, 66 years; range, 45-79 years) were identified for our cohort. Vessel disease involvement included severe ECA stenosis >or= 70% in 11 patients and ipsilateral ICA occlusion in all patients. Presenting symptoms included signs of transient ischemic attack, stroke, and amaurosis fugax. ECA stenting was associated with preservation of neurological status in 11 patients and resolution of symptoms in 5 patients at a median follow-up time of 26 months (range, 1-87 months; mean, 29 months). Symptomatic in-stent restenosis did not occur within any patient during the follow-up course. Conclusion We found ECA stenting in symptomatic ipsilateral ICA disease to be a potentially effective strategy to preserve neurological function and to relieve ischemic symptoms. Further investigation with larger studies and longer follow-up periods is warranted to elucidate the true indications of this management strategy.

Objective Identification and complete interruption of fistulae are essential but not always obvious during the surgical treatment of spinal dural arteriovenous fistulae (dAVFs). We examined cases in which we identified and confirmed surgical obliteration of a spinal dAVF with the aid of microscope-integrated near-infrared indocyanine green (ICG) videoangiography. Methods ICG videoangiography was performed during 6 surgical interventions in which 6 intradural dorsal AVFs (type I) were interrupted. An operating microscope-integrated light source containing infrared excitation light illuminated the operating field and was used to visualize an intravenous bolus of ICG. The locations of fistulae, feeding arteries, and draining veins and documentation of occlusion of the fistulae were compared with findings on preoperative and postoperative digital subtraction angiography. Results ICG videoangiography identified the fistulous point(s), feeding arteries, and draining veins in all 6 cases, as confirmed by immediate postoperative selective spinal angiography. In 1 case, intraoperative ICG ruled out an additional questionable fistula at a contiguous level suspected on the preoperative angiography. Conclusion Microscope-based ICG videoangiography is simple and provides real-time information about the precise location of spinal dAVFs. During spinal dAVF surgery, this technique can be useful as an independent form of angiography or as an adjunct to intra or postoperative digital subtraction angiography. Larger series are needed to determine whether use of this modality could reduce the need for immediate postoperative spinal angiography after obliteration of intradural dorsal AVFs.

OBJECTIVE: The supracerebellar infratentorial (SCIT) approach can be performed at the midline (median variant), lateral to the midline (paramedian variant), or at the level of the angle formed by the transverse and sigmoid sinuses (extreme lateral variant). We analyzed our experience with SCIT approaches for the surgical treatment of cavernous malformations of the brainstem (CMBs). METHODS: Demographic, clinical, radiologic, and surgical data from 45 patients (20 males and 25 females; mean age, 36.2 years) with CMBs surgically removed through SCIT approaches were reviewed retrospectively. Anatomic information was explored using cadaver head dissection. RESULTS: Twenty-three lesions were in the midbrain, 3 were at the midbrain and extended to the thalamus, 9 were at the pontomesencephalic junction, and 10 were in the upper pons. All patients presented with hemorrhage. The median variant was used in 13 patients, the paramedian variant in 9, and the extreme lateral variant in 23. Intraoperatively, all CMBs were associated with a developmental venous anomaly. At last follow-up, 88% of the patients were the same or better. After a mean follow-up of 20 months, their mean Glasgow Outcome Scale score was 4.1. CONCLUSION: SCIT approaches provide excellent exposure to CMBs located at the posterior incisural space, not only in the midline but also in the posterolateral surface of the upper pons and midbrain. Careful preoperative planning and neuronavigational assistance are needed to determine the best angle of attack and trajectory for SCIT approaches. Refined microsurgical techniques are paramount to achieve safe surgical removal of CMBs with good outcomes.