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The use of modern transfemoral balloon guide catheters (BGC) for flow reversal during carotid artery stenting is scarcely described in the literature but represents a promising and efficient technique for embolic protection.To describe a flow-reversal technique using the Walrus BGC (Q'Apel Medical Inc.) and report our center's experience.We performed a retrospective analysis of data for consecutive patients aged 18 years or older who underwent elective carotid artery stenting with the use of flow reversal through the Walrus BGC between July 2020 and September 2021. Patient characteristics, procedural details, and clinical follow-up were evaluated.One hundred and five patients were included. Mean age was 69.8 ± 9.4 years, and 36 (34.3%) were women. The most common comorbidities were hyperlipidemia (76.2%) and hypertension (57.1%). Fifty-nine (56.2%) patients were symptomatic. Ninety-nine (94.3%) patients had stenosis ≥70%. Contralateral stenosis ≥50% was present in 44 patients (41.9%). Distal filters were used after flow reversal was established in 90 patients (85.7%). Angioplasty was performed in 85 patients (80.9%). Stenting was successful in 100% of cases. No periprocedural transient ischemic attacks (TIAs) or strokes occurred. Stroke occurred in 2 patients (1.9%) during the 30-day follow-up period, resulting in 1 (0.9%) death.In our experience, this technique was safe, feasible, and efficient, with 100% technical success and no periprocedural thromboembolic complications. More extensive studies are needed to establish the role of proximal protection with flow reversal using modern BGCs.

Studies about the transradial technique and experience with this approach abound in the neurointerventional literature, but studies focusing on patient perspectives and preferences with respect to transfemoral or transradial access are scarce.Patients from our center who underwent both transradial and transfemoral approaches for diagnostic and interventional cerebral angiograms on distinct occasions between January 2016 and January 2021 were identified and interviewed by phone regarding their experience with these access approaches. The first question was regarding the choice for an eventual next procedure (radial, femoral, or no preference). The second question addressed reasons (pain, bruising, complications, recovery time, mobility, failure of one approach, and comfort associated with puncture of the respective area).Forty-four patients were interviewed. Thirty-one (70.4%) preferred radial, 9 (20.5%) preferred femoral, and 4 (9.1%) had no preference. Most frequent reasons for radial preference were recovery time (67.7%), bruising (51.6%), and pain (48.4%). Most frequent reasons in femoral preference were pain (55.6%), mobility (33.3%), and failure of the other approach (33.3%). Recovery time (67.7% vs. 22.2%; P = 0.023) and comfort of puncturing the area (45.2% vs. 0%; P = 0.015) were significantly more frequent reasons for radial preference, whereas failure of the other approach (0% vs. 33.3%; P = 0.008) was a significantly more frequent reason for femoral preference.Most patients preferred the transradial approach. Evaluating the reasons behind their preference can help operators to better understand patient perspectives and improve quality of care.

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.

The Pipeline Flex Embolization Device with Shield technology (PED-Shield [Medtronic, Dublin, Ireland]) is a third-generation flow diverter. Surface modification of the mesh with phosphorylcholine covalently bound to the metal struts aims to reduce thrombogenicity. In the present study, we report the results from the first U.S. series of patients with intracranial aneurysms treated with the PED-Shield and a comprehensive systematic literature review.We retrospectively collected the patient demographics, aneurysm characteristics, procedural details, and periprocedural complications from our prospectively maintained endovascular database (April 2021 to July 2021). Our literature review encompassed 3 databases (PubMed, Embase, and MEDLINE).Ten patients with 11 anterior circulation unruptured wide-necked aneurysms (10 saccular, 1 fusiform) were included. The average patient age was 64.7 years (range, 45-86 years), and 9 were women. One device demonstrated insufficient distal opening. No other technical issues or intraprocedural complications had occurred. After the procedure, 1 patient had developed a groin hematoma and 1 had experienced a small intracranial hemorrhage, with no clinical repercussions. All patients were discharged with dual-antiplatelet therapy. In the review, we identified 15 studies. Most had been conducted in Europe and South America and 3 were U.S. case reports of compassionate use of the device.In our initial periprocedural experience with the PED-Shield for intracranial aneurysm treatment, the device demonstrated an excellent performance and no major complications. Further studies are required to evaluate the long-term follow-up results and the safety of different antiplatelet regimens.

Collateral circulation is associated with improved functional outcome in patients with large vessel occlusion acute ischemic stroke (AIS) who undergo reperfusion therapy. Assessment of collateral flow can be time consuming, subjective, and difficult because of complex neurovasculature. This study assessed the ability of multiple artificial intelligence algorithms in determining collateral flow of patients with AIS.Two hundred patients with AIS between March 2019 and January 2020 were included in this retrospective study. Peak arterial computed tomography perfusion volumes were used to assess collateral scores. Neural networks were developed for dichotomized (≥50% or50%) and multiclass (0% filling, 0%-50% filling, 50%-100% filling, or 100% filling) collateral scoring. Maximum intensity projections from axial and anteroposterior (AP) views were synthesized for each bone subtracted three-dimensional volume and used as network inputs separately and together, along with three-dimensional data. Training:testing:validation splits of 60:30:10 and 20 iterations of Monte Carlo cross-validation were used. Network performance was assessed using 95% confidence intervals of accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).The axial and AP input combination provided the most accurate results for dichotomized classification: accuracy, 0.85 ± 0.01; sensitivity, 0.88 ± 0.02; specificity, 0.82 ± 0.03; PPV, 0.86 ± 0.02; and NPV, 0.83 ± 0.03. Similarly, the axial and AP input combination provided the best results for multiclass classification: accuracy, 0.80 ± 0.01; sensitivity, 0.64 ± 0.01; specificity, 0.85 ± 0.01; PPV, 0.65 ± 0.02; and NPV, 0.85 ± 0.01.This study reports one of the first artificial intelligence-based algorithms capable of accurately and efficiently assessing collateral flow of patients with AIS. This automated method for determining collateral filling could streamline clinical workflow, reduce bias, and aid in clinical decision making for determining reperfusion-eligible patients.

Big data studies are on the rise in vascular neurosurgery. Advanced computer processing power combined with vast amounts of digitized data collected and stored by electronic medical records have led to studies using machine learning, deep learning algorithms, and their applications-artificial intelligence. Big data is challenging the gold standard model of randomized controlled trials introducing more pragmatic research designs including registries and registry-based randomized trails. There is a maturation of cerebrovascular disease studies. Studies have larger patient sample sizes allowing for more compelling conclusions that we reach with higher confidence. This pertains to diagnosis, treatment, outcomes, and a more nuanced understanding of less common presentations of illnesses. The following review will critically discuss big data applications in vascular neurosurgery as well as its implications in quality improvement, innovation, and global neurosurgery.

Background The use of balloon guide catheters (BGCs) for proximal flow arrest during neurointerventional procedures has been limited owing to the incompatibility of BGCs with large-bore aspiration catheters and difficulty in device navigation. The objective of our study was to describe the use of the Walrus catheter (Q'Apel Medical, Fremont, California, USA), a new 8F BGC, with a variety of aspiration catheters and procedures requiring flow arrest. Methods Consecutive cases using Walrus BGCs for proximal flow arrest during mechanical thrombectomy for acute stroke cases were recorded. The procedure indication, vessel occlusion site, technique, first-pass effect (modified thrombolysis in cerebral infarction score of 2C or 3 after the first recanalization attempt), and complications were recorded and evaluated statistically. Results Our study included 57 patients who had undergone mechanical thrombectomy. In addition to mechanical thrombectomy, the Walrus BGC was used in conjunction with the following techniques: stent retrieval in 2 patients (3.5%), stent retrieval followed by aspiration (Solumbra technique) in 41 (71.9%), and aspiration followed by stent retrieval in 14 patients (24.6%). Eight different aspiration catheters were used in 56 of these 57 procedures. The first-pass effect (modified thrombolysis in cerebral infarction score of 2C and 3) was achieved in 36 (63.2%) of 57 procedures. Two patients (3.5%) had experienced intraoperative complications (symptomatic intracerebral hemorrhage) and one patient (1.8%) had died in-hospital. Conclusions Our results have demonstrated that the Walrus BGC is a highly navigable 8F guide catheter compatible with most available aspiration catheters. Owing to its compatibility with most available aspiration catheters and ease of use, the Walrus BGC is a valuable addition to the tools available for mechanical thrombectomy.

Statins have been reported to reduce the rates of recurrence and improve the resolution of chronic subdural hematomas (cSDHs) treated surgically or conservatively. No studies have investigated the effect of statins in patients treated with middle meningeal artery embolization.We performed a retrospective search of our cSDH database to identify patients treated with middle meningeal artery embolization alone. Only patients with at least 1 noncontrast computed tomography scan obtained 3-12 weeks after embolization were included. Hematoma volumes were measured at baseline and last noncontrast computed tomography available. The volumes, volume reduction, speed of resolution, and recurrence were compared between patients already receiving statin therapy when admitted and those who were not.Forty-six patients with 50 cSDHs were included (statins, 17 patients with 18 cSDHs vs. nonstatins, 29 patients with 32 cSDHs). The statin group had a significantly higher rate of hyperlipidemia (statin, 64.7% vs. nonstatin, 31%, P = 0.03) but similar demographics, remaining comorbidities, medications, and hematoma thickness, axial and coronal lengths, and baseline volumes. The time between procedure and last noncontrast computed tomography scan was similar between groups. There were no differences between the groups regarding volume reduction, final volume, speed of resolution, complete resolution, and recurrence.Patients treated with middle meningeal artery embolization alone who were on statin therapy had no differences in cSDH resolution or recurrence compared to those who were not on statin therapy. It is possible that the anti-inflammatory effects of statins may not be relevant when supply to the dura is interrupted by treatment with embolization.

BackgroundThe perception of a steep learning curve associated with transradial access has resulted in its limited adoption in neurointervention despite the demonstrated benefits, including decreased access-site complications.ObjectiveTo compare learning curves of transradial versus transfemoral diagnostic cerebral angiograms obtained by five neurovascular fellows as primary operator.MethodsThe first 100–150 consecutive transradial and transfemoral angiographic scans performed by each fellow between July 2017 and March 2020 were identified. Mean fluoroscopy time per artery injected (angiographic efficiency) was calculated as a marker of technical proficiency and compared for every 25 consecutive procedures performed (eg, 1–25, 26–50, 51–75).ResultsWe identified 1242 diagnostic angiograms, 607 transradial and 635 transfemoral. The radial cohort was older (64.3 years vs 62.3 years, p=0.01) and demonstrated better angiographic efficiency (3.4 min/vessel vs 3.7 min/vessel, p=0.03). For three fellows without previous endovascular experience, proficiency was obtained between 25 and 50 transfemoral angiograms. One fellow achieved proficiency after performing 25–50 transradial angiograms; and the two other fellows, in ConclusionTechnical proficiency improved significantly over time for both access types, typically requiring between 25 and 50 diagnostic angiograms to achieve asymptomatic improvement in efficiency. Reduced access-site complications and decreased fluoroscopy time were benefits associated with transradial angiography.

Background Immediate and accurate detection of intracranial hemorrhages (ICHs) is essential to provide a good clinical outcome for patients with ICH. Artificial intelligence has the potential to provide this, but the assessment of these methods needs to be investigated in depth. This study aimed to assess the ability of Canon's AUTOStroke Solution ICH detection algorithm to accurately identify patients both with and without ICHs present. Methods Data from 200 ICH and 102 non-ICH patients who presented with stroke-like symptoms between August 2016 and December 2019 were collected retrospectively. Patients with ICH had at least one of the following hemorrhage types: intraparenchymal (n = 181), intraventricular (n = 45), subdural (n = 13), or subarachnoid (n = 19). Noncontrast computed tomography scans were analyzed for each patient using Canon's AUTOStroke Solution ICH algorithm to determine which slices contained hemorrhage. The algorithm's ability to detect ICHs was assessed using sensitivity, specificity, positive predictive value, and negative predictive value. Percentages of cases correctly identified as ICH positive and negative were additionally calculated. Results Automated analysis demonstrated the following metrics for identifying hemorrhage slices within all 200 patients with ICH (95% confidence intervals): sensitivity = 0.93 ± 0.03, specificity = 0.93 ± 0.01, positive predictive value = 0.85 ± 0.02, and negative predictive value = 0.98 ± 0.01. A total of 95% (245 of 258) of ICH volumes were correctly triaged, whereas 88.2% (90 of 102) of non-ICH cases were correctly classified as ICH negative. Conclusions Canon's AUTOStroke Solution ICH detection algorithm was able to accurately detect intraparenchymal, intraventricular, subdural, and subarachnoid hemorrhages in addition to accurately determine when an ICH was not present. Having this automated ICH detection method could drastically improve treatment times for patients with ICH.

Background Coiling of wide-necked aneurysms requires high-density packing of coils within the aneurysm, which necessitates adequate microcatheter access and navigability. The Comaneci device, introduced in the United States in 2019, is a retrievable stent that can be used as an adjunct to coiling of a wide-necked aneurysm without limiting flow. We present a case series and systematic review of use of this device. Methods All cases involving use of the device at our institute between May 1, 2019, and April 30, 2020, were reviewed. A comprehensive systematic review of the literature was conducted using PubMed and EMBASE and a review of eligible article bibliographies. Results Five patients underwent Comaneci-assisted wide-necked aneurysm coiling during the study period; 4 were treated via a radial artery approach, and 1 was treated via a femoral artery approach. Two patients presented with subarachnoid hemorrhage: 1 had a ruptured posterior inferior cerebellar artery aneurysm (Hunt-Hess 5, Fisher 4), and 1 had a ruptured middle cerebral artery aneurysm (Hunt-Hess 2, Fisher 1). Mean aneurysmal neck size was 4.4 ± 0.8mm; mean aspect ratio was 1.2 ± 0.3. Raymond-Roy 1 occlusion was achieved in all aneurysms except the posterior inferior cerebellar artery aneurysm. Systematic literature review identified 4 articles that found use of the Comaneci device to treat wide-necked aneurysms to be effective. Conclusions This device can be used with transfemoral and transradial approaches, allowing for continued flow through the parent vessel during the coiling procedure while providing a scaffold for dense coiling of the aneurysm and its neck.

Background and Purpose: The degree to which the coronavirus disease 2019 (COVID-19) pandemic has affected systems of care, in particular, those for time-sensitive conditions such as stroke, remains poorly quantified. We sought to evaluate the impact of COVID-19 in the overall screening for acute stroke utilizing a commercial clinical artificial intelligence platform. Methods: Data were derived from the Viz Platform, an artificial intelligence application designed to optimize the workflow of patients with acute stroke. Neuroimaging data on suspected patients with stroke across 97 hospitals in 20 US states were collected in real time and retrospectively analyzed with the number of patients undergoing imaging screening serving as a surrogate for the amount of stroke care. The main outcome measures were the number of computed tomography (CT) angiography, CT perfusion, large vessel occlusions (defined according to the automated software detection), and severe strokes on CT perfusion (defined as those with hypoperfusion volumes >70 mL) normalized as number of patients per day per hospital. Data from the prepandemic (November 4, 2019 to February 29, 2020) and pandemic (March 1 to May 10, 2020) periods were compared at national and state levels. Correlations were made between the inter-period changes in imaging screening, stroke hospitalizations, and thrombectomy procedures using state-specific sampling. Results: A total of 23 223 patients were included. The incidence of large vessel occlusion on CT angiography and severe strokes on CT perfusion were 11.2% (n=2602) and 14.7% (n=1229/8328), respectively. There were significant declines in the overall number of CT angiographies (−22.8%; 1.39–1.07 patients/day per hospital, P P P P P =0.9) and comprehensive stroke center hospitalizations (18.8% versus 11.0%, P =0.4). Conclusions: A significant decline in stroke imaging screening has occurred during the COVID-19 pandemic. This analysis underscores the broader application of artificial intelligence neuroimaging platforms for the real-time monitoring of stroke systems of care.

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.

OBJECTIVE Flow diverter devices have revolutionized the treatment of intracranial aneurysms (IAs) since their approval in 2011 and have continued to evolve. The devices have been widely adopted across institutions and centers over the past decade; however, long-term follow-up after treatment with the Pipeline embolization device (PED) is not well described in the literature. The authors’ institution was among the first to begin using PEDs, allowing them to report their series of patients treated with flow diverters ≥ 10 years ago. In this study, the authors aimed to evaluate the long-term angiographic and clinical outcomes of these patients and review lessons learned along the way. METHODS The authors performed a retrospective review of their institution’s IA database from January 2007 to July 2012. All patients with IAs treated with a PED prior to July 2012 were included. Clinical and angiographic characteristics were extracted. Available angiographic follow-up at 1, 3, 5, and 10 years was reported. RESULTS A total of 83 patients with 92 aneurysms treated with a PED ≥ 10 years ago were identified and included in the study. The mean aneurysm dome diameter was 9.2 (SD 5.7) mm, the mean aneurysm height was 10.4 (SD 6.8) mm, and the mean neck width was 4.1 (SD 2.4) mm. Only 1 (1.1%) aneurysm was ruptured at presentation. Eight (8.7%) aneurysms were recurrences of previous treatment modalities. The morphology was saccular in 77 (83.7%) aneurysms, fusiform in 14 (15.2%), and blister-like in 1 (1.1%). Among saccular aneurysms, 60 (77.9%) were wide-necked. Seventy-five (81.5%) aneurysms were in the internal carotid artery, 12 (13.0%) were vertebrobasilar, 3 (3.3%) were in the middle cerebral artery, and 2 (2.2%) were in the posterior cerebral artery. Angiographic follow-up at 1, 3, 5, and 10 years was available for 75, 59, 50, and 15 patients, respectively. The complete occlusion rates at 1, 3, 5, and 10 years were 94.7%, 96.6%, 96.0%, and 100%, respectively. The retreatment rates at 1, 3, 5, and 10 years were 8.0%, 6.8%, 8.0%, and 6.7%, respectively. CONCLUSIONS The authors provide their single-institution series of IA patients treated with a PED ≥ 10 years ago, with the first report of 10-year follow-up for the available patients.

BackgroundExtensive clot burden in tandem strokes accounts for poor mechanical thrombectomy (MT) outcomes. Several studies have shown the benefit of balloon guide catheters (BGCs) in MT and carotid artery stenting.ObjectiveIn view of this potential benefit, to investigate the safety and effectiveness of proximal flow arrest using a BGC during concurrent MT and carotid revascularization for tandem stroke treatment in a comparative, propensity score-matched (PSM) study.MethodsPatients with a tandem stroke identified from our endovascular database were dichotomized into groups treated with BGCs versus conventional guide catheters. One-to-one PSM adjustment for baseline demographics and treatment selection bias using nearest-neighbor matching was performed. Patient demographics, presentation characteristics, and procedural details were recorded. Outcomes assessed were final modified Thrombolysis in Cerebral Infarction (mTICI) grade, periprocedural symptomatic intracranial hemorrhage (sICH) rate, in-hospital mortality, and 90-day modified Rankin Scale (mRS) score. Mann-Whitney U test and multivariate logistic regression were performed to compare procedural parameters and clinical outcomes.ResultsConcurrent carotid revascularization (stenting with/without angioplasty) and MT was performed in 125 cases (BGC: 85; no BGC: 40). After PSM (40 patients/group), the BGC group had a significantly shorter procedure duration (77.9 vs 61.5 min; OR=0.996; P=0.006), lower discharge National Institutes of Health Stroke Scale score (8.0 vs 11.0; OR=0.987; P=0.042), and higher odds of 90-day mRS 0–2 score (52.3% vs 27.5%; OR=0.34; P=0.040). On multivariate regression, the BGC group had a significantly higher first pass effect rate (mTICI 2b or 3)(OR=1.115, 95% CI 1.015 to 1.432; P=0.013) and lower periprocedural sICH rate (OR=0.615, 95% CI 0.406 to 0.932; P=0.025). No difference in in-hospital mortality was observed (OR=1.591, 95% CI 0.976 to 2.593; P=0.067).ConclusionBGCs used for concurrent MT–carotid revascularization with flow arrest were safe and resulted in superior clinical and angiographic outcomes in patients with a tandem stroke.

Rapid and accurate diagnosis of large vessel occlusions (LVOs) in acute ischemic stroke (AIS) patients using automated software could improve clinical workflow in determining thrombectomy in eligible patients. Artificial intelligence-based methods could accomplish this; however, their performance in various clinical scenarios, relative to clinical experts, must be thoroughly investigated. We aimed to assess the ability of Canon’s AUTOStroke Solution LVO application in properly detecting and locating LVOs in AIS patients. Data from 202 LVO and 101 non-LVO AIS patients who presented with stroke-like symptoms between March 2019 and February 2020 were collected retrospectively. LVO patients had either an internal carotid artery (ICA) ( n = 59), M1 middle cerebral artery (MCA) ( n = 82) or M2 MCA ( n = 61) occlusion. Computed tomography angiography (CTA) scans from each patient were pushed to the automation platform and analyzed. The algorithm’s ability to detect LVOs was assessed using accuracy, sensitivity and Matthews correlation coefficients (MCCs) for each occlusion type. The following results were calculated for each occlusion type in the study (accuracy, sensitivity, MCC): ICA = (0.95, 0.90, 0.89), M1 MCA = (0.89, 0.77, 0.78) and M2 MCA = (0.80, 0.51, 0.59). For the non-LVO cohort, 98% (99/101) of cases were correctly predicted as LVO negative. Processing time for each case was 69.8 ± 1.1 seconds (95% confidence interval). Canon’s AUTOStroke Solution LVO application was able to accurately identify ICA and M1 MCA occlusions in addition to almost perfectly assessing when an LVO was not present. M2 MCA occlusion detection needs further improvement based on the sensitivity results displayed by the LVO detection algorithm.

BackgroundRadial artery access for transarterial procedures has gained recent traction in neurointerventional due to decreased patient morbidity, technical feasibility, and improved patient satisfaction. Upper extremity transvenous access (UETV) has recently emerged as an alternative strategy for the neurointerventionalist, but data are limited. Our objective was to quantify the use of UETV access in neurointerventions and to measure failure and complication rates.MethodsAn international multicenter retrospective review of medical records for patients undergoing UETV neurointerventions or diagnostic procedures was performed. We also present our institutional protocol for obtaining UETV and review the existing literature.ResultsOne hundred and thirteen patients underwent a total of 147 attempted UETV procedures at 13 centers. The most common site of entry was the right basilic vein. There were 21 repeat puncture events into the same vein following the primary diagnostic procedure for secondary interventional procedures without difficulty. There were two minor complications (1.4%) and five failures (ie, conversion to femoral vein access) (3.4%).ConclusionsUETV is safe and technically feasible for diagnostic and neurointerventional procedures. Further studies are needed to determine the benefit over alternative venous access sites and the effect on patient satisfaction.

BackgroundThere are no reports that describe complete flow control using concurrent transient rapid ventricular pacing or intravenous (IV) adenosine and afferent arterial balloon flow arrest to aid transvenous embolization of cerebral arteriovenous malformations (AVM). We describe our experience with the use of this technique in patients undergoing transvenous AVM embolization.MethodsConsecutive patients in whom transvenous embolization was attempted at our institute between January 2017 and July 2019 were included. Anatomical AVM features, number of embolization stages, technique of concurrent transient rapid ventricular pacing and afferent arterial balloon flow arrest, complications, and clinical and radiological outcomes were recorded and tabulated.ResultsTransvenous AVM embolization was attempted in 12 patients but abandoned in two patients for technical reasons. Complete embolization was achieved in 10 patients, five of whom had infratentorial AVMs. All 10 had a single primary draining vein. Rapid ventricular pacing was used in nine cases; IV adenosine injection was used in one case to achieve cardiac standstill. Complete AVM nidus obliteration was achieved with excellent neurologic outcome in nine cases, with transvenous embolization alone in two cases, and with staged transarterial followed by transvenous embolization in the others. Two patients developed hemorrhagic complications intraprocedurally. One patient was managed conservatively and the other operatively with AVM excision and hematoma evacuation; both made an excellent recovery without any neurologic deficits at 3 months.ConclusionComplete flow control using concurrent transient rapid ventricular pacing with afferent arterial balloon flow arrest technique is safe and feasible for transvenous embolization of select AVMs.

Computed tomography perfusion (CTP) is crucial for acute ischemic stroke (AIS) patient diagnosis. To improve infarct prediction, enhanced image processing and automated parameter selection have been implemented in Vital Images’ new CTP+ software. We compared CTP+ with its previous version, commercially available software (RAPID and Sphere), and follow-up diffusion-weighted imaging (DWI). Data from 191 AIS patients between March 2019 and January 2020 was retrospectively collected and allocated into endovascular intervention ( n = 81) and conservative treatment ( n = 110) cohorts. Intervention patients were treated for large vessel occlusion, underwent mechanical thrombectomy, and achieved successful reperfusion of thrombolysis in cerebral infarction 2b/2c/3. Conservative treatment patients suffered large or small vessel occlusion and did not receive intravenous thrombolysis or mechanical thrombectomy. Infarct and penumbra were assessed using intervention and conservative treatment patients, respectively. Infarct and penumbra volumes were segmented from CTP+ and compared with 24-h DWI along with RAPID, Sphere, and Vitrea. Mean infarct differences (95% confidence intervals) and Spearman correlation coefficients (SCCs) between DWI and each CTP software product for intervention patients are: CTP+ = (5.8 ± 5.9 ml, 0.62), RAPID = (10.0 ± 5.2 ml, 0.73), Sphere = (3.0 ± 6.0 ml, 0.56), Vitrea = (7.2 ± 4.9 ml, 0.66). For conservative treatment patients, mean infarct differences and SCCs are: CTP+ = (–8.0 ± 5.4 ml, 0.64), RAPID = (–25.6 ± 11.5 ml, 0.60), Sphere = (–25.6 ± 8.0 ml, 0.66), Vitrea = (1.3 ± 4.0 ml, 0.72). CTP+ performed similarly to RAPID and Sphere in addition to its semi-automated predecessor, Vitrea, when assessing intervention patient infarct volumes. For conservative treatment patients, CTP+ outperformed RAPID and Sphere in assessing penumbra. Semi-automated Vitrea remains the most accurate in assessing penumbra, but CTP+ provides an improved workflow from its predecessor.

Butterfly glioblastoma (bGBM) is a grade 4 glioma with a poor prognosis. Surgical treatment of these cancers has been reviewed in the literature with some recent studies supporting resection as a safe and effective treatment instead of biopsy and adjuvant therapy. This meta-analysis was designed to determine whether there are significant differences in overall survival (OS) and postoperative neurologic deficits (motor, speech, and cranial nerve) following intervention in patients who underwent tumor resection as part of their treatment, compared to patients who underwent biopsy without surgical resection. A literature search was conducted using PubMed (National Library of Medicine) and Embase (Elsevier) to identify articles from each database's earliest records to May 25, 2021, that directly compared the outcomes of biopsy and resection in bGBM patients and met predetermined inclusion criteria. A meta-analysis was conducted to compare the effects of the two management strategies on OS and postoperative neurologic deficits. Six articles met our study inclusion criteria. OS was found to be significantly longer for the resection group at 6 months (odds ratio [OR] 2.94, 95% confidence interval [CI] 1.23-7.05) and 12 months (OR 3.75, 95% CI 1.10-12.76) than for the biopsy group. No statistically significant differences were found in OS at 18 and 24 months. Resection was associated with an increased rate of postoperative neurologic deficit (OR 2.05, 95% CI 1.02-4.09). Resection offers greater OS up to 1 year postintervention than biopsy alone; however, this comes at the cost of higher rates of postoperative neurologic deficits.

Statins have been proposed to improve the resolution of chronic subdural hematoma (cSDH), with conflicting results likely due to underpowered analysis or confounding factors, such as the use of antithrombotic medication. We performed a systematic literature review and meta-analysis to better elucidate the effect of statin therapy on cSDH recurrence.We performed a comprehensive search of PubMed, MEDLINE, and Embase databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Articles were included if the number of recurrences requiring surgical evacuation or leading to neurological deterioration was reported and could be extracted separately for patients who did or did not receive statin therapy.Seven studies were included, comprising 1359 cSDH patients (statin therapy, 449 vs. non-statin therapy, 910). Age was not different between groups (P = 0.548). The proportion of men was significantly different (statin, 80.1% vs. non-statin, 74.7%; P = 0.02). Use of antithrombotic medication was significantly higher (P = 0.005) in the statin group (11.7%) than in the non-statin group (7.3%). The statin group had a non-significant lower odds of recurrence (odds ratio 0.80, 95% confidence interval 0.35-1.81). In an exploratory data analysis of 4 studies without a difference between groups in antithrombotic medication use, the statin group had significantly lower odds of recurrence (odds ratio 0.29, 95% confidence interval 0.17-0.50).Overall, we found that statin use did not result in lower odds of cSDH recurrence, likely due to a dilution caused by the higher rate of patients on antithrombotic medications in the statin group.

BACKGROUND AND PURPOSE: Clot perviousness in acute ischemic stroke is a potential CT imaging biomarker for mechanical thrombectomy efficacy. We investigated the association among perviousness, clot cellular composition, and first-pass effect. MATERIALS AND METHODS: In 40 mechanical thrombectomy–treated cases of acute ischemic stroke, we calculated perviousness as the difference in clot density on CT angiography and noncontrast CT. We assessed the proportion of fibrin/platelet aggregates, red blood cells, and white blood cells on clot histopathology. We tested for linear correlation between histologic components and perviousness, differences in components between “high” and “low” pervious clots defined by median perviousness, and differences in perviousness/composition between cases that did and did not achieve a first-pass effect. RESULTS: Perviousness significantly positively and negatively correlated with the percentage of fibrin/platelet aggregates (P = .001) and the percentage of red blood cells (P = .001), respectively. Higher pervious clots had significantly greater fibrin/platelet aggregate content (P = .042). Cases that achieved a first-pass effect (n = 14) had lower perviousness, though not significantly (P = .055). The percentage of red blood cells was significantly higher (P = .028) and the percentage of fibrin/platelet aggregates was significantly lower (P = .016) in cases with a first-pass effect. There was no association between clot density on NCCT and clot composition or first-pass effect. Receiver operating characteristic analysis indicated that clot composition was the best predictor of first-pass effect (area under receiver operating characteristic curve: percentage of fibrin/platelet aggregates = 0.731, percentage of red blood cells = 0.706, perviousness = 0.668). CONCLUSIONS: Clot perviousness on CT is associated with a higher percentage of fibrin/platelet aggregate content. Histologic data and, to a lesser degree, perviousness may have value in predicting first-pass outcome. Imaging metrics that more strongly reflect clot biology than perviousness may be needed to predict a first-pass effect with high accuracy.

Background Trends in mechanical thrombectomy have emphasized larger bore aspiration catheters that may be difficult to deploy from a radial access point due to size constraints or need to obtain sheathless access. As such, many neurointerventionists are reticent to attempt thrombectomy through transradial access (TRA) for fear of worse outcomes. Objective To explore whether mechanical thrombectomy could be achieved safely and effectively through the transradial route. Methods We retrospectively analyzed the records of patients undergoing mechanical thrombectomy at our academic institute between January 2018 and January 2019, which corresponded to a time when we began to transition to TRA for neurointerventions, including mechanical thrombectomy. We compared the procedural details and clinical outcomes of patients undergoing mechanical thrombectomy using TRA with those using transfemoral access (TFA). Results During the study period, 44 patients underwent mechanical thrombectomy with TRA and 129 with TFA. There was no statistically significant difference in door-to-access time, door-to-reperfusion time, or first-pass recanalization rate. There was no significant difference in modified Rankin Scale (mRS) score at discharge, mRS score at last follow-up, or length of stay. There were 7 access-site complications in the TFA group and none in the TRA group. One patient in the TRA group required crossover to TFA. Conclusion Mechanical thrombectomy can be performed safely and effectively from a TRA site without compromising recanalization times or rates. TRA has superior access-site complication profiles compared to TFA.

BackgroundRadial access has become popular among neurointerventionalists because it has favorable risk profiles compared with femoral access. Difficulties in accessing or navigating the radial artery have been viewed as a reason to convert to femoral access, but ulnar artery access may prevent complications associated with transfemoral procedures.ObjectiveTo evaluate the safety and feasibility of ulnar access for neurointerventions and diagnostic neuroangiographic procedures.MethodsConsecutive patients who underwent diagnostic angiography or neurointerventional procedures via ulnar access between July 1, 2019 and April 15, 2020 were included. Data recorded were demographics, procedure indication, devices, technique, and complications. Descriptive analysis was performed.ResultsUlnar artery access was obtained for 21 procedures in 18 patients (mean age 70.3±7.8 years; nine men). Procedures included 13 diagnostic angiograms and eight neurointerventions (3 left middle meningeal artery embolization, 1 of which was aborted; 2 carotid artery stenting; 2 angioplasty; 1 mechanical thrombectomy for in-stent thrombosis). A right-sided approach with ultrasound guidance was used for all cases except one. Indications included small caliber radial artery (n=9), radial artery occlusion (n=10), and radial artery preservation for potential bypass (n=2). A 5-French slender sheath was used for diagnostic angiography; a 6-French slender sheath was used for neurointerventions. No case required conversion to femoral access. Two patients had minor hematomas after the procedure; one other had ulnar artery occlusion on 30-day ultrasonography.ConclusionUlnar access is safe and feasible for diagnostic and interventional neuroangiographic procedures. It provides a useful alternative to radial access, potentially avoiding complications associated with femoral access.

BackgroundPatients with cerebral aneurysms treated with the Pipeline embolization device (PED) are maintained on dual antiplatelet therapy (DAPT) to prevent thromboembolic complications. Rates of minor, “nuisance” bleeding in these patients remain unknown. We sought to evaluate the frequency and factors associated with this bleeding and its effect on DAPT compliance.MethodsWe performed a multicenter retrospective cohort study on consecutive cases of intracranial aneurysms treated with PED. Patient characteristics, aneurysm characteristics, and bleeding complications were analyzed. Severity of bleeding was defined according to a previously published classification defining nuisance bleeding as easy bruising, bleeding from small cuts, petechia, and ecchymosis.Results245 PED aneurysm procedures on 243 patients were retrospectively collected from three academic centers over a 4.25-year period. Sixty-seven patients (27%) had nuisance bleeds. Patients with a higher risk of nuisance bleeding were older (59.1±3.4 vs . 54.7±2.2, P=0.032). Patients with nuisance bleeds were more likely to have their DAPT regimen changed or dose lowered (29% vs 8.3%, PConclusionsNuisance bleeding was a common complaint of PED-treated aneurysm patients maintained on DAPT. Increasing age and aneurysmal occlusion at 6 months were the only factors predictive of nuisance bleeds. Clinicians were more likely to adjust antiplatelet regimens or stop DAPT early given a nuisance bleed.

In acute ischemic stroke (AIS) patients, eligibility for endovascular intervention is commonly determined through computed tomography perfusion (CTP) analysis by quantifying ischemic tissue using perfusion parameter thresholds. However, thresholds are not uniform across all analysis methods due to dependencies on patient demographics and computational algorithms. This study aimed to investigate optimal perfusion thresholds for quantifying infarct and penumbra volumes using two post-processing CTP algorithms: Vitrea Bayesian and singular value decomposition plus (SVD+). We utilized 107 AIS patients (67 non-intervention patients and 40 successful reperfusion of thrombolysis in cerebral infarction (2b/3) patients). Infarct volumes were predicted for both post-processing algorithms through contralateral hemisphere comparisons using absolute time-to-peak (TTP) and relative regional cerebral blood volume (rCBV) thresholds ranging from +2.8 seconds to +9.3 seconds and –0.23 to –0.56 respectively. Optimal thresholds were determined by minimizing differences between predicted CTP and 24-hour fluid-attenuation inversion recovery magnetic resonance imaging infarct. Optimal thresholds were tested on 60 validation patients (30 intervention and 30 non-intervention) and compared using RAPID CTP software. Among the 67 non-intervention and 40 intervention patients, the following optimal thresholds were determined: intervention Bayesian: TTP = +4.8 seconds, rCBV = –0.29; intervention SVD+: TTP = +5.8 seconds, rCBV = –0.29; non-intervention Bayesian: TTP = +5.3 seconds, rCBV = –0.32; non-intervention SVD+: TTP = +6.3 seconds, rCBV = –0.26. When comparing SVD+ and Bayesian post-processing algorithms, optimal thresholds for TTP were significantly different for intervention and non-intervention patients. rCBV optimal thresholds were equal for intervention patients and significantly different for non-intervention patients. Comparison with commercially utilized software indicated similar performance.

BackgroundCT perfusion (CTP) infarct and penumbra estimations determine the eligibility of patients with acute ischemic stroke (AIS) for endovascular intervention. This study aimed to determine volumetric and spatial agreement of predicted RAPID, Vitrea, and Sphere CTP infarct with follow-up fluid attenuation inversion recovery (FLAIR) MRI infarct.Methods108 consecutive patients with AIS and large vessel occlusion were included in the study between April 2019 and January 2020 . Patients were divided into two groups: endovascular intervention (n=58) and conservative treatment (n=50). Intervention patients were treated with mechanical thrombectomy and achieved successful reperfusion (Thrombolysis in Cerebral Infarction 2b/2 c/3) while patients in the conservative treatment group did not receive mechanical thrombectomy or intravenous thrombolysis. Intervention and conservative treatment patients were included to assess infarct and penumbra estimations, respectively. It was assumed that in all patients treated conservatively, penumbra converted to infarct. CTP infarct and penumbra volumes were segmented from RAPID, Vitrea, and Sphere to assess volumetric and spatial agreement with follow-up FLAIR MRI.ResultsMean infarct differences (95% CIs) between each CTP software and FLAIR MRI for each cohort were: intervention cohort: RAPID=9.0±7.7 mL, Sphere=−0.2±8.7 mL, Vitrea=−7.9±8.9 mL; conservative treatment cohort: RAPID=−31.9±21.6 mL, Sphere=−26.8±17.4 mL, Vitrea=−15.3±13.7 mL. Overlap and Dice coefficients for predicted infarct were (overlap, Dice): intervention cohort: RAPID=(0.57, 0.44), Sphere=(0.68, 0.60), Vitrea=(0.70, 0.60); conservative treatment cohort: RAPID=(0.71, 0.56), Sphere=(0.73, 0.60), Vitrea=(0.72, 0.64).ConclusionsSphere proved the most accurate in patients who had intervention infarct assessment as Vitrea and RAPID overestimated and underestimated infarct, respectively. Vitrea proved the most accurate in penumbra assessment for patients treated conservatively although all software overestimated penumbra.

There is wide variation in the reported size of ruptured intracranial aneurysms and methods of size estimation. There is widespread belief that small aneurysms

Background Modern science and healthcare generate vast amounts of data, and, coupled with the increasingly inexpensive and accessible computing, a tremendous opportunity exists to use these data to improve care. A better understanding of data science and its relationship to neurosurgical practice will be increasingly important as we transition into this modern “big data” era. Methods A review of the literature was performed for key articles referencing big data for neurosurgical care or related topics. Results In the present report, we first defined the nature and scope of data science from a technical perspective. We then discussed its relationship to the modern neurosurgical practice, highlighting key references, which might form a useful introductory reading list. Conclusions Numerous challenges exist going forward; however, organized neurosurgery has an important role in fostering and facilitating these efforts to merge data science with neurosurgical practice.

Non-galenic pial arteriovenous fistulas (NGPAVFs) are rare cerebrovascular pathologies accounting for only 1.6%-4.8% of all brain vascular malformations. We performed a comprehensive review of NGPAVF cases reported in the literature to further characterize their clinical patterns of presentation, angiographic features, management, clinical outcomes, and complications.We searched PubMed, Google Scholar, and Embase from each database's earliest records to April 2022 for all relevant English language articles. A total of 3280 articles were screened to identify those that met prespecified inclusion criteria. Differences in clinical outcomes between children (≤18 years old) and adults (18 years old) and those articles in which NGPAVFs were associated with the presence of a varix or a hemorrhage were statistically examined.A total of 242 patients in 86 articles were included. The mean patient age was 18.51 ± 18.80 years. The male-to-female ratio was 1.44:1. Headache was the most common initial presentation (42.6%) in the study cohort. Hemorrhage occurred at a significantly higher frequency in adults (P = 0.004), whereas more children presented with congestive heart failure (P0.001). Surgical, endovascular, and combination therapy led to comparable rates of complete NGPAVF obliteration (86.8%, 85.2%, and 88.5%, respectively). Fifty-nine patients (24.4%) experienced a complication, ranging from minor neurological deficit to severe hemorrhage. The mortality rate for the overall cohort was 3.3%, and all deceased patients had a varix associated with their fistulas.To our knowledge, we report the largest literature review describing the clinical course and characteristics of NGPAVFs. All treatment approaches resulted in favorable obliteration rates and overall patient outcomes.

BackgroundThe transradial approach (TRA) for mechanical thrombectomy (MT) for acute ischemic stroke has been limited by the size of catheters usable in the radial artery, with the smaller access site precluding balloon-guide catheter (BGC) use. However, promising results have been reported for a TRA with a sheathless BGC (sTRA). We sought to perform a comparative study of MT with a BGC via the sTRA versus the transfemoral approach (TFA).MethodsA retrospective review of our MT database was conducted. Baseline, procedure-related, and outcome data were compared for patients aged ≥18 years with anterior circulation large vessel occlusion, Alberta Stroke Program Early CT Score ≥6, and prestroke modified Rankin Scale score ≤2 treated with either approach.ResultsNinety-three consecutive patients (34 sTRA and 59 TFA) were included. Both groups had similar demographics, comorbidities, stroke severity, intravenous alteplase use, and occlusion location. Mean time from puncture to final recanalization was faster in the sTRA group (29 vs 36 min, p=0.059) despite a higher access site crossover rate in the sTRA group (11.8% vs 0%, p=0.016). There were no differences between groups regarding last modified Thombolysis in Cerebral Infarction score; first-pass or modified first-pass effect; time from last known well to puncture; use of stent-retriever, aspiration, or combination first approach; number of passes; symptomatic intracranial hemorrhage; hospital stay; 90-day functional independence; and mortality. National Institutes of Health Scale score and modified first-pass effect were the only independent predictors of poor outcomes.ConclusionsComparable patients treated with MT via the sTRA or TFA had similar angiographic and clinical outcomes.

Background and Purpose: The modified Thrombolysis in Cerebral Infarct (mTICI) score is used to grade angiographic outcome after endovascular thrombectomy. We sought to identify factors that decrease the accuracy of intraprocedural mTICI. Methods: We performed a 2-center retrospective cohort study comparing operator (n=6) mTICI scores to consensus scores from blinded adjudicators. Groups were also assessed by dichotomizing mTICI scores to 0–2a versus 2b–3. Results: One hundred thirty endovascular thrombectomy procedures were included. Operators and adjudicators had a pairwise agreement in 96 cases (73.8%). Krippendorff α was 0.712. Multivariate analysis showed endovascular thrombectomy overnight (odds ratio [OR]=3.84 [95% CI, 1.22–12.1]), lacking frontal (OR, 5.66 [95 CI, 1.36–23.6]), or occipital (OR, 7.18 [95 CI, 2.12–24.3]) region reperfusion, and higher operator mTICI scores (OR, 2.16 [95 CI, 1.16–4.01]) were predictive of incorrectly scoring mTICI intraprocedurally. With dichotomized mTICI scores, increasing number of passes was associated with increased risk of operator error (OR, 1.93 [95 CI, 1.22–3.05]). Conclusions: In our study, mTICI disagreement between operator and adjudicators was observed in 26.2% of cases. Interventions that took place between 22:30 and 4:00, featured frontal or occipital region nonperfusion, higher operator mTICI scores, and increased number of passes had higher odds of intraprocedural mTICI inaccuracy.

BackgroundRecurrence of intracranial aneurysms after endovascular coiling is a serious clinical concern.ObjectiveWe hypothesized that recurrence is associated with aneurysm morphology and flow, as well as the coil intervention and the induced flow modifications.MethodsWe collected 52 primary-coiling aneurysm cases that were either occluded (n=34) or recurrent (n=18) at >1 year follow-up. We created aneurysm models from pre-coiling digital subtraction angiographic images, calculated aneurysm morphology, simulated pre-coiling hemodynamics, modeled coil deployment, and obtained post-coiling hemodynamics for each case. We performed univariable analysis on 26 morphologic, treatment-specific, and hemodynamic parameters to distinguish between recurrent and occluded groups, and multivariable analysis to identify independently significant parameters associated with recurrence. Univariable analysis was also performed on ruptured and unruptured aneurysm subcohorts separately to investigate if they shared specific significant parameters.ResultsRecurrence was associated with pre-coiling aneurysm morphologic and flow parameters including larger size (maximum dimension and volume), larger neck (diameter, area, and neck-to-parent-artery ratio), and higher flow momentum and kinetic energy. Recurrence was also associated with lower coil packing (packing density and uncoiled volume), higher post-treatment flow (velocity, momentum, and kinetic energy), lower post-treatment washout time, and higher post-treatment impingement force at the neck. Multivariable analysis identified two aneurysmal characteristics (neck diameter and pre-coiling flow kinetic energy), one coil packing parameter (uncoiled volume), and one post-treatment hemodynamic parameter (flow momentum) that were independently associated with recurrence. In ruptured aneurysms, recurrence was associated with larger neck (diameter and area), whereas in unruptured aneurysms, recurrence was associated with larger size (maximum dimension and volume). In both subcohorts, recurrence was associated with higher post-coiling flow momentum and kinetic energy.ConclusionRecurrence at >1 year after coil treatment is associated with intrinsic aneurysm characteristics, coiling itself, and flow changes induced by coiling. Larger aneurysm size and neck, less coil packing, and higher intra-aneurysmal flow before and after coiling predict recurrence.

Various studies have suggested that age ≥80 years is associated with a higher rate of complications after carotid artery stenting (CAS). The Buffalo Risk Assessment Scale (BRASS) predicts complications in symptomatic patients undergoing CAS. Application of the BRASS has shown the ability to improve patient selection. We used the BRASS system to evaluate whether the higher rate of complications associated with CAS in the elderly is related to vascular anatomy.A retrospective review of CAS was performed at our institution over 7 years. Demographic information, anatomic characteristics, BRASS categorization, and outcome measures were compared between elderly (≥80 years) and younger patients (80 years).The study included 447 patients: 335 patients (75%)80 years and 112 patients (25%) ≥80 years. There were significantly more elderly patients in the high-risk BRASS category (P0.01), and more young patients in the low-risk BRASS category (P = 0.04). The complication rates in the 2 groups were similar. Older patients were more likely to harbor complex vascular anatomy: they had significantly higher rates of types II and III aortic arches (P = 0.01 and P0.01, respectively), higher percentage of tortuous carotid vessels (P0.01), and higher rates of hostile anatomy for deployment of distal embolic protection devices (P = 0.02).Complex vascular anatomy, rather than age, is the key factor behind the higher CAS-associated complication rate in the elderly. Complications can be avoided through proper patient selection and stratifying patients based on anatomic characteristics, which can be achieved through the BRASS scoring system.

Introduction Embolization of the middle meningeal artery (MMA) has emerged as a minimally invasive means of managing subdural hematoma. The purpose of this study was to systematically review the literature on the safety and effectiveness of this treatment and to share our clinical experience. Methods This review was registered with PROSPERO. PubMed, CINAHL, EMBASE, and the Cochrane Library were searched using MeSH (Medical Subject Headings) terms for MMA embolization and chronic subdural hematoma (CSDH) from January 2000 to November 2018. All articles in the English language literature describing MMA embolization for CSDH were included, irrespective of study design. Consecutive patients who underwent MMA embolization at our hospital between January 2017 and June 2018 comprised our clinical experience. Results Fifteen studies with 193 procedures were included in the review. Ninety-five cases (49.2%) involved primary MMA embolization; 88 embolizations (45.6%) for recurrent CSDH and 10 (5.2%) for prophylaxis after surgical evacuation were performed. Recurrence after MMA embolization requiring further treatment occurred in 7 cases (3.6%). All other patients had symptomatic relief with no further recurrence. No procedure-related complications were reported. Polyvinyl alcohol was the most commonly used material. Our series included 8 patients treated with Onyx. All had symptom relief and significant reduction in hematoma size; no recurrences or procedure-related complications were observed. Conclusions MMA embolization of CSDH is safe and effective for CSDH treatment based on a documented recurrence rate of 3.6% and lack of reported complications.

Background Minimally invasive surgery procedures, including stereotactic catheter aspiration and clearance of intracerebral hemorrhage (ICH) with recombinant tissue plasminogen activator hold a promise to improve outcome of supratentorial brain hemorrhage, a morbid and disabling type of stroke. A recently completed Phase III randomized trial showed improved mortality but was neutral on the primary outcome (modified Rankin scale score 0 to 3 at 1 yr). Objective To assess surgical performance and its impact on the extent of ICH evacuation and functional outcomes. Methods Univariate and multivariate models were used to assess the extent of hematoma evacuation efficacy in relation to mRS 0 to 3 outcome and postulated factors related to patient, disease, and protocol adherence in the surgical arm (n = 242) of the MISTIE trial. Results Greater ICH reduction has a higher likelihood of achieving mRS of 0 to 3 with a minimum evacuation threshold of ≤15 mL end of treatment ICH volume or ≥70% volume reduction when controlling for disease severity factors. Mortality benefit was achieved at ≤30 mL end of treatment ICH volume, or >53% volume reduction. Initial hematoma volume, history of hypertension, irregular-shaped hematoma, number of alteplase doses given, surgical protocol deviations, and catheter manipulation problems were significant factors in failing to achieve ≤15 mL goal evacuation. Greater surgeon/site experiences were associated with avoiding poor hematoma evacuation. Conclusion This is the first surgical trial reporting thresholds for reduction of ICH volume correlating with improved mortality and functional outcomes. To realize the benefit of surgery, protocol objectives, surgeon education, technical enhancements, and case selection should be focused on this goal.

BackgroundLiterature on volumetric resolution and recurrence over time between surgical evacuation alone (SEA) and standalone middle meningeal artery embolization (MMAE) in comparable chronic subdural hematoma (cSDH) patients is limited.MethodsA retrospective database analysis of cSDH patients managed with either SEA or MMAE was conducted. Propensity-score matching was performed for axial and coronal lengths, maximum diameter, and midline shift. Volumetric measurements at multiple time intervals and recurrence were compared between the groups.Results48 matched hematoma pairs in patients with similar demographics, comorbidities, medications, and symptoms were obtained. Median volume was significantly lower at 24 hours in the SEA group (12.6 mL vs 52.7 mL, pConclusionsIn comparable cSDH patients, SEA resulted in better volumetric outcomes in immediate postoperative and early follow-up periods, as expected. However, this difference was not significant at more distant follow-up intervals. Furthermore, surgical patients experienced a significantly higher rate of recurrence.

BackgroundThe effectiveness of transradial stroke thrombectomy has been limited by guide catheter size and lack of good balloon options. In this study we describe our technique for the use of a sheathless 8-French balloon guide catheter (Walrus) through radial access and present our initial clinical experience.MethodsThis was a retrospective case series of consecutive patients who underwent mechanical thrombectomy for large vessel occlusion using the sheathless catheter over a period of 3 months. Clinical characteristics, procedural details, reperfusion success (modified Thrombolysis in Cerebral Infarction (mTICI) 2b–3 grade), first-pass effect (FPE; mTICI reperfusion grade 2c or 3 with a single pass), access site complications and clinical improvement at discharge were recorded. A descriptive analysis was performed.ResultsAmong the 10 patients in the series, median age was 77 years (IQR 75–79) and three were women. All patients had a baseline modified Rankin Scale score ≤2. Median admission National Institutes of Health Stroke Scale (NIHSS) score was 12.5 (IQR 9–16). Four patients received intravenous alteplase before mechanical thrombectomy. Eight patients had M1 occlusion and two had proximal M2 occlusion. The median radial artery diameter was 2.5 mm (IQR 2.5–2.7). Successful reperfusion was achieved in all patients. FPE was achieved in six patients. No access site-related complications or post-procedural intracranial hemorrhages occurred. All patients had improvement in NIHSS score at discharge.ConclusionsThe use of this sheathless catheter for transradial access was safe and feasible. The technique can potentially improve the outcomes of transradial access for stroke intervention.

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

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

Extracranial-to-intracranial (EC-IC) bypass was first described by Yasargil in the 1960s for treatment of symptomatic distal internal carotid artery (ICA) and/or proximal middle cerebral artery (MCA) steno-occlusive disease through direct anastomosis. Subsequent bypass trials failed to demonstrate benefit for overall outcomes and stroke rates compared with best medical therapy. However, the procedure remained in the neurosurgeon's armament, with studies showing benefits in select patient populations. With advancements in technology, patient selection has become more comprehensive.To provide a contemporary evaluation of EC-IC bypass from our high-volume cerebrovascular center, focusing on associated clinical outcomes.Consecutive patients who underwent direct EC-IC bypass surgeries for symptomatic distal ICA and/or proximal MCA steno-occlusive disease between April 2015 and September 2019 were identified retrospectively. Medical records were reviewed to collect demographics, clinical presentation, computed tomography perfusion imaging findings, transcranial Doppler results, procedure indication, donor vessel types, anastomosis site, bypass patency, periprocedural complications, postprocedural complications, symptom recrudescence, repeat or new interventions, subjective improvements, and modified Rankin Scale scores.We identified 27 patients who underwent 32 EC-IC bypass procedures. The rate of ipsilateral stroke was 9.4%, with a median follow-up of 8 months (IQR, 4-13 months). Patients experienced a 22.3% improvement in modified Rankin Scale scores, and 70.3% of patients reported subjective improvement and satisfaction at follow-up.Direct EC-IC bypass remains a viable option for revascularization in symptomatic patients with distal ICA and/or proximal MCA steno-occlusive disease.

Introduction: Artificial intelligence (AI) can automate the detection and triage of ICH. ENRICH is a RCT evaluating the efficacy of MIS for ICH. AI ENRICH is a prospective trial operating within and in parallel to the ENRICH trial that utilizes an AI application, Viz RECRUIT and ICH VOLUME to identify and segment ICH to quickly identify potentially eligible subjects. Methods: Non-contrast CT scans performed at 5 participating US hospitals were evaluated specifically for a parenchymal hemorrhage by Viz ICH VOLUME. Participating health care professionals downloaded a phone application that allowed one to be notified for any hemorrhage ≥ 5 mL. Time metrics included the onset of CT scan, phone alert, and user recognition of that alert. Results: Over a combined period of 220 days, 8714 CT scans were evaluated by the Viz ICH VOLUME application. Of these, 257 CT scans were determined to contain an ICH yielding a total of 45 patients that met ENRICH criteria for trial inclusion (30-80 mL). The median time from CT scan to cell phone notification was 2:52 minutes (IQR=0.002) . The median time from cell phone notification to the user viewing the CT scan was 3:00 minutes (IQR=55.5 minutes), which was altered by a few significant delays in recognizing the alert (e.g. coordination of alerts and call schedules). After segregating the 4 weeks after ENRICH restarted on 7/14/20 into 2 week blocks, recognition of an alert within 5 minutes increased from 9% to 61.5% at the first site and 36% to 61.5% at second site - demonstrating the ability of alerts to improve site engagement and active screening for new subjects. Conclusions: In conclusion, Viz ICH VOLUME can screen large numbers of CT scans and send alerts within minutes to medical professionals. Studies relying on radiographic selection criteria may benefit from automated screening, although participating health care providers need to make use of the technology in order to maximize benefit.

BACKGROUND: Intra-procedural assessment of reperfusion during mechanical thrombectomy (MT) for emergent large vessel occlusion (LVO) stroke, is traditionally based on subjective evaluation of digital subtraction angiographs (DSA). However, semi-quantitative diagnostic tools which encode hemodynamic properties in DSAs, such as angiographic parametric imaging (API), exist and may be used for evaluation of reperfusion during MT. The objective of this study was to use data-driven approaches, such as convolutional neural networks (CNN) with API maps to automatically assess reperfusion in neuro-vasculature during MT procedures based on the modified thrombolysis in cerebral infarction (mTICI) scale. METHODS: DSAs from patients undergoing MTs of anterior circulation LVOs, were collected, temporally cropped to isolate late arterial and capillary phases and quantified using API peak height (PH) maps. PH maps were normalized to reduce injection variability. A CNN was developed, trained, and tested to classify PH maps into 2 outcomes (mTICI0,1,2a / mTICI2b,2c,3) or 3 outcomes (mTICI0,1,2a / mTICI2b / mTICI2c,3) respectively. Ensembled networks were used to combine information from multiple views (anteroposterior and lateral). RESULTS: The study included 383 DSAs. For the 2-outcome classification, average accuracy was 81.0% (95% CI: 79.0%−82.9%) and, area under the receiver operating characteristic curve (AUROC) was 0.86 (0.84–0.88). For the 3-outcome classification, average accuracy was 64.0% (62.0–66.0), AUROCs were 0.85 (0.83–0.87), 0.74 (0.71–0.77) and, 0.78 (0.76–0.81) for the mTICI0,1,2a, mTICI2b, and mTICI2c,3 classes respectively. CONCLUSIONS: This study demonstrated the feasibility of using hemodynamic information in API maps with data-driven models to autonomously assess intra-procedural reperfusion during MT.

BackgroundFew studies have compared technical success and effectiveness of transradial access (TRA) versus transfemoral access (TFA) for mechanical thrombectomy (MT) for acute ischemic stroke (AIS). We compared the two approaches for technical success, effectiveness, and outcomes.MethodsWe retrospectively compared TRA with TFA for AIS MT at our institute. We additionally performed a systematic review and meta-analysis of studies describing the use of TRA alone or in comparison with TFA for MT. Primary outcomes included rate of successful reperfusion (thrombolysis in cerebral infarction (TICI)>2b), number of passes, access-site complications, and 3- month mortality and favorable functional outcomes (modified Rankin Scale (mRS) score 0–2).ResultsA total of 222 consecutive patients (TRA=93, TFA=129) were included in our case series. The rate of successful reperfusion was significantly higher for the TFA cohort (91.4% vs 79.6%, P=0.01) with lower mean number of passes (1.8±1.2 vs 2.4±1.6, P=0.014). Three-month mortality in the TFA group was lower (22.1% vs 40.9% for the TRA cohort (P=0.004), with a higher rate of favorable functional outcomes (51.3% vs 34.1%, P=0.015). A meta-analysis of 10 studies showed significant heterogeneity in rates of successful reperfusion (57.1% to 95.6%, heterogeneity=67.55%, P=0.001). None of the previous comparative studies reported 3-month mortality and functional outcomes.ConclusionsThis case series demonstrate a higher successful reperfusion rate, fewer passes, lower 3-month mortality, and improved 3-month functional outcomes with TFA. The systematic review highlights the inadequacy of existing evidence. Prospective comparative studies are needed before a ‘radial-first’ approach can be adopted for stroke intervention.

Objectives Cost-effectiveness of endovascular therapy (EVT) is a key consideration for broad use of this approach for emergent large vessel occlusion stroke. We evaluated the evidence on cost-effectiveness of EVT in comparison with best medical management from a global perspective. Materials and Methods This systematic review of studies published between January 2010 and May 2020 evaluated the cost effectiveness of EVT for patients with large vessel occlusion acute ischemic stroke. The gain in quality adjusted life year (QALY) and incremental cost-effectiveness ratio (ICER), expressed as cost per QALY resulting from EVT, were recorded. The study setting (country, economic perspective), decision model, and data sources used in economic models of EVT cost-effectiveness were recorded. Results Twenty-five original studies from 12 different countries were included in our review. Five of these studies were reported from a societal perspective; 18 were reported from a healthcare system perspective. Two studies used real-world data. The time horizon varied from 1 year to a lifetime; however, 18 studies reported a time horizon of >10 years. Twenty studies reported using outcome data from randomized, controlled clinical trials for their models. Nineteen studies reported using a Markov model. Incremental QALYs ranged from 0.09–3.5. All studies but 1 reported that EVT was cost-effective. Conclusions Evidence from different countries and economic perspectives suggests that EVT for stroke treatment is cost-effective. Most cost-effectiveness studies are based on outcome data from randomized clinical trials. However, there is a need to study the cost-effectiveness of EVT based solely on real-world outcome data.