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Adoption of middle meningeal artery embolization in the management of chronic subdural hematomas has led to a renewed interest in dural vascular anatomy. The readily identifiable major dural arteries and potential hazards associated with their embolization are well described. Less emphasized are several levels of intrinsic dural angioarchitecture, despite their more direct relationship to dural based diseases, such as subdural hematoma and dural fistula. Fortunately, microvascular aspects of dural anatomy, previously limited to ex vivo investigations, are becoming increasingly accessible to in vivo visualization, setting the stage for synthesis of the old and the new, and providing a rationale for the endovascular approach to subdural collections in particular. In contrast with traditional anatomical didactics, where descriptions advance from larger trunks to smaller pedicles, we present a strategic approach that proceeds from a fundamental understanding of the dural microvasculature and its relationship to larger vessels.

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

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.

Background and Purpose: Aneurysmal wall enhancement (AWE) on vessel wall magnetic resonance imaging (VW-MRI) has been described as a new imaging biomarker of unstable unruptured intracranial aneurysms (UIAs). Previous studies of symptomatic UIAs are limited due to small sample sizes and lack of AWE quantification. Our study aims to investigate whether qualitative and quantitative assessment of AWE can differentiate symptomatic and asymptomatic UIAs. Methods: Consecutive patients with UIAs were prospectively recruited for vessel wall magnetic resonance imaging at 3T from October 2014 to October 2019. UIAs were categorized as symptomatic if presenting with sentinel headache or oculomotor nerve palsy directly related to the aneurysm. Evaluation of wall enhancement included enhancement pattern (0=none, 1=focal, and 2=circumferential) and quantitative wall enhancement index (WEI). Univariate and multivariate analyses were used to identify the parameters associated with symptoms. Results: Two hundred sixty-seven patients with 341 UIAs (93 symptomatic and 248 asymptomatic) were included in this study. Symptomatic UIAs more frequently showed circumferential AWE than asymptomatic UIAs (66.7% versus 17.3%, P P P =0.01; odds ratio=3.32 for WEI [95% CI, 1.51–7.26], P =0.003). The combination of AWE pattern and WEI had an area under the curve of 0.91 to identify symptomatic UIAs, with a sensitivity of 95.7% and a specificity of 73.4%. Conclusions: In a large cohort of UIAs with vessel wall magnetic resonance imaging, both AWE pattern and WEI were independently associated with aneurysm-related symptoms. The qualitative and quantitative features of AWE can potentially be used to identify unstable intracranial aneurysms.

BackgroundThe safety and efficacy of bridging therapy with intravenous thrombolysis (IVT) and mechanical thrombectomy (MT) in patients with large core infarct has not been sufficiently studied. In this study, we compared the efficacy and safety outcomes between patients who received IVT+MT and those treated with MT alone.MethodsThis is a retrospective analysis of the Stroke Thrombectomy Aneurysm Registry (STAR). Patients with Alberta Stroke Program Early CT Score (ASPECTS) ≤5 treated with MT were included in this study. Patients were divided into two groups based on pre-treatment IVT (IVT, no IVT). Propensity score matched analysis were used to compare outcomes between groups.ResultsA total of 398 patients were included; 113 pairs were generated using propensity score matching analyses. Baseline characteristics were well balanced in the matched cohort. The rate of any intracerebral hemorrhage (ICH) was similar between groups in both the full cohort (41.4% vs 42.3%, P=0.85) and matched cohort (38.55% vs 42.1%, P=0.593). Similarly, the rate of significant ICH was similar between the groups (full cohort: 13.1% vs 16.9%, P=0.306; matched cohort: 15.6% vs 18.95, P=0.52). There was no difference in favorable outcome (90-day modified Rankin Scale 0–2) or successful reperfusion between groups. In an adjusted analysis, IVT was not associated with any of the outcomes.ConclusionPretreatment IVT was not associated with an increased risk of hemorrhage in patients with large core infarct treated with MT. Future studies are needed to assess the safety and efficacy of bridging therapy in patients with large core infarct.

BackgroundReducing intracranial hemorrhage (ICH) can improve patient outcome in acute ischemic stroke (AIS) intervention. We sought to identify ICH risk factors after AIS thrombectomy.MethodsThis is a retrospective review of the Stroke Thrombectomy and Aneurysm Registry (STAR) database. All patients who underwent AIS thrombectomy with available ICH data were included. Multivariable regression models were developed to identify predictors of ICH after thrombectomy. Subgroup analyses were performed stratified by symptom status and European Cooperative Acute Stroke Study (ECASS) grade.ResultsThe study cohort comprised 6860 patients. Any ICH and symptomatic ICH (sICH) occurred in 25% and 7% of patients, respectively. Hemorrhagic infarction 1 (HI1) occurred in 36%, HI2 in 24%, parenchymal hemorrhage 1 (PH1) in 22%, and PH2 in 17% of patients classified by ECASS grade. Intraprocedural complications independently predicted any ICH (OR 3.8083, PConclusionsThis study identified ICH risk factors after AIS thrombectomy using real-world data. There was a propensity towards a reduced sICH risk with direct aspiration. Procedural complications and ethnicity were predictors congruent between categories of any ICH, sICH, PH1, and PH2. Further investigation of technique and ethnicity effects on ICH and outcomes after AIS thrombectomy is warranted.

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

BackgroundAlthough studies continue to demonstrate lower complications in neurointerventions using transradial access (TRA) compared with transfemoral approaches, anatomic radial variants can be difficult to navigate and remain one of the frequent causes of access site conversion.ObjectiveTo evaluate predictors of TRA failure in neuroendovascular patients with radial loops and suggest a protocol for managing these anomalies.MethodsA prospective collection of patients undergoing TRA at participating institutions from July 2018 to September 2020 was reviewed. Patients with a radial loop were identified. Patient demographics and procedural characteristics were evaluated to determine predictors of both TRA failure and successful reduction of the radial loop.ResultsWe identified 32 transradial neurointerventions in which patients had radial loops. Twenty-two (68.8%) were identified by diagnostic angiography, and the majority were performed for evaluation or treatment of an aneurysm (56.3%). TRA failure occurred in 13 (40.6%) of the cohort and happened more frequently in patients over 60 years of age (p=0.01) and those with recurrent radial artery diameters ≤2 mm (p=0.02). Of the 19 patients who had successful TRA, 12 (63.2%) procedures were performed through the recurrent radial artery.ConclusionAlthough radial loops are associated with high transradial failure rates, our results suggest that the presence of a loop is not an absolute contraindication to TRA. Therefore, we recommend attempting loop navigation using our protocol. Patient age, vascular tortuosity, and recurrent radial artery size should help dictate when to convert to an alternative access site.

BackgroundThe transcirculation approach (TCA) for stent-assisted coiling (SAC) of intracranial aneurysms may be useful for certain wide-neck bifurcation aneurysms as well as those with acute-angle efferent branches.ObjectiveTo describe a multicenter experience using the TCA for SAC.MethodsA multicenter, retrospective study (2016–2020) of aneurysm treatment using SAC via the TCA. Angiographic outcome was scored using the Raymond Scale (adequate occlusion 1 and 2), and clinical outcome was scored using a modified Rankin Scale (good outcome 0–2)ResultsTwenty-nine patients with 29 aneurysms were included (62.1% female; average age 61; 89.7% unruptured; 13.8% previously treated; average dome size 6.4 mm; average neck 4.4 mm). Aneurysm locations included internal carotid artery–fetal posterior cerebral artery (n=4), internal carotid artery terminus (n=4), anterior communicating artery (n=8), vertebral artery–posterior inferior cerebellar artery (n=2), and basilar tip (n=11). The TCA used communicating arteries (93.1%; average 1.6 mm), intermediate catheters (51.7%), jailing technique (62.1%), and staged procedures (10.3%). The most common stent was the Neuroform Atlas (Stryker; 69%). Immediate adequate occlusion was obtained in 75.9%, and five patients with inadequate occlusion progressed to adequate occlusion at follow-up. One (3.4%) procedural complication occurred: a watershed stroke in the setting of baseline four-vessel extracranial disease. Two patients had a poor outcome unrelated to the TCA. The majority of patients (86.4%) had a good clinical outcome. One case of in-stent stenosis due to non-compliance with medication was seen, which resolved with medication resumption.ConclusionsThe TCA for SAC can be performed for a variety of aneurysms with a low complication rate and good clinical outcomes.

The purpose of this study was to examine the association with in-hospital mortality of 8 illness severity scores in patients with aneurysmal subarachnoid hemorrhage (aSAH).In a retrospective cohort study, we investigated the association with in-hospital mortality of admission Hunt and Hess (HH) score, Fisher grade, severity of illness and risk of mortality scores, and serial Glasgow coma scale (GCS) score in patients with aSAH. We also explored the changes in GCS between admission and discharge using a multivariate model adjusting for age, clinical vasospasm, and external ventricular drain status.Data from 480 patients with aSAH, of which 383 (79.8%) aneurysms were in the anterior circulation, were included in analysis. Patients were female (n=340, 70.8%) with a median age of 56 (interquartile range: 48 to 66) years. The majority (n=332, 69.2%) had admission HH score 3 to 5, Fisher grade 3 to 4 (n=437, 91%), median severity of illness 3 (range: 1 to 4), median risk of mortality 3 (range: 1 to 4), and median admission GCS of 13 (interquartile range: 7 to 15). Overall, 406 (84.6%) patients received an external ventricular drain, 469 (97.7%) underwent aneurysm repair, and 60 died (12.5%). Compared with admission HH score, GCS 24 hours after admission (area under the curve: 0.84, 95% confidence interval [CI]: 0.79-0.88) and 24 hours after aneurysm repair (area under the curve: 0.87, 95% CI: 0.82-0.90) were more likely to be associated with in-hospital mortality. Among those who died, the greatest decline in GCS was noted between 24 hours after aneurysm repair and discharge (-3.38 points, 95% CI: -4.17, -2.58).Compared with admission HH score, GCS 24 hours after admission (or 24 h after aneurysm repair) is more likely to be associated with in-hospital mortality after aSAH.

Introduction: Non-traumatic subarachnoid hemorrhage (SAH) is strongly linked to hypertension, a condition highly influenced by common genetic variants. For complex diseases influenced by genetic and environmental factors, genetic predisposition plays a key role in earlier onset. We tested the hypothesis that persons with a higher polygenic burden of hypertension-related alleles have SAH at younger ages. Methods: We analyzed data from the UK Biobank, a large cohort study that enrolled over 500,000 Britons aged 40-69. We included participants of European descent. We constructed two polygenic risk scores (PRS) using 807 independent genetic variants known to associate with higher systolic and diastolic blood pressure (BP). We fitted linear regression to assess the relationship between these PRS and the age-of-onset of SAH, using product terms to test for interaction with sex. We subsequently implemented Mendelian Randomization analyses using the inverse variance weighted and weighted median methods to evaluate causality. Results: We evaluated a total of 1,178 SAH cases (mean age, 58; female sex, 722 [61.3%]). When evaluating all participants jointly, there was no association between the systolic BP PRS and age-of-onset for SAH (p=0.130). There was a significant interaction between the PRS and sex (p=0.002): each additional standard deviation of the systolic BP PRS was associated with an earlier onset of SAH in females (beta, -1.45; 95% CI, -2.31 to -0.58; p=0.001), but not in males (adjusted beta, 0.83; 95% CI, -0.37 to 2.02; p=0.176). In MR analyses, a 10mmHg increase in genetically determined systolic BP was associated with a 5-year earlier onset of SAH in female participants using both the inverse variance weighted (beta, -4.72; 95% CI, -7.34 to -2.10; p Conclusions: Genetically determined hypertension is associated with earlier onset of non-traumatic SAH in women. These results indicate that genetic predisposition may play a more important causal role in younger patients and point to genetic information as possible tools for early identification of high-risk individuals.

Introduction: Lung cancer has been linked to increased risk of thromboembolic events, including stroke. However, a causal relationship between lung cancer and ischemic stroke (IS) has yet to be established. Methods: We conducted a two-stage study using observational and genetic data from the UK Biobank, a large cohort study that enrolled over 500,000 Britons aged 40-69. We included participants of European descent. In Stage I, we used logistic regression to test the association between self-reported / ICD-defined lung cancer and risk of IS. In Stage II, we constructed a polygenic risk score (PRS) using 31 independent genetic variants known to associate with lung cancer, fitted logistic regression to assess the relationship between this PRS and risk of IS, and implemented the inverse variance weighted method of Mendelian randomization (MR). We tested for horizontal pleiotropy using the MR-Egger and MR Pleiotropy Residual Sum and Outlier (MR-PRESSO) approaches. Results: Out of 409,629 participants of European descent enrolled in the UK Biobank, there were 5,060 IS cases (mean age, 61.6 [standard deviation 6.5]; female sex, 1813 [35.8%]). The prevalence of lung cancer was 1.9% (n=94) and 0.5% (n=1,961) among persons with and without IS, respectively (unadjusted p Conclusions: Genetically determined lung cancer is associated with increased risk of ischemic stroke. These findings provide evidence for a causal link between lung cancer and ischemic stroke. Further studies are needed to identify the biological pathways that mediate this link.

BACKGROUND AND PURPOSE: The Neuroform Atlas is a new microstent to assist coil embolization of intracranial aneurysms that recently gained FDA approval. We present a postmarket multicenter analysis of the Neuroform Atlas stent. MATERIALS AND METHODS: On the basis of retrospective chart review from 11 academic centers, we analyzed patients treated with the Neuroform Atlas after FDA exemption from January 2018 to June 2019. Clinical and radiologic parameters included patient demographics, aneurysm characteristics, stent parameters, complications, and outcomes at discharge and last follow-up. RESULTS: Overall, 128 aneurysms in 128 patients (median age, 62 years) were treated with 138 stents. Risk factors included smoking (59.4%), multiple aneurysms (27.3%), and family history of aneurysms (16.4%). Most patients were treated electively (93.7%), and 8 (6.3%) underwent treatment within 2 weeks of subarachnoid hemorrhage. Previous aneurysm treatment failure was present in 21% of cases. Wide-neck aneurysms (80.5%), small aneurysm size (

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

Background and purpose Blunt cerebrovascular injury (BCVI) is associated with a significant risk of ischemic stroke when left untreated. Cross-sectional imaging is vital to early BCVI diagnosis and treatment; however, conventional luminal vessel imaging is limited in its ability to evaluate for vessel wall pathology. The purpose of this study is to evaluate the ability of vessel wall magnetic resonance imaging (VWI) to detect and evaluate BCVI in acutely injured trauma patients relative to neck computed tomographic angiography (CTA). Materials and methods Trauma patients with suspected BCVI on initial neck CTA were prospectively recruited for VWI evaluation. Two neuroradiologists blinded to patient clinical history and CTA findings evaluated each artery independently on VWI and noted the presence and grade of BCVI. These results were subsequently compared to neck CTA findings relative to expert clinical consensus review. Interrater reliability of VWI for detecting BCVI was evaluated using a weighted Cohen κ-statistic. Results Ten trauma patients (40 cervical arteries) were prospectively evaluated using both CTA and VWI. Out of 18 vascular lesions identified as suspicious for BCVI on CTA, six lesions were determined to represent true BCVI by expert consensus review. There was almost perfect agreement between VWI and expert consensus regarding the presence and grade of BCVI (κ = 0.82). This agreement increased when considering only low grade BCVI. There was only fair agreement between CTA and expert clinical consensus (κ = 0.36). This agreement decreased when considering only low grade BCVI. Conclusions VWI can potentially accurately identify and evaluate BCVI in acutely injured trauma patients with excellent inter-rater reliability.

BackgroundThe transradial approach (TRA) has gained increasing popularity for neuroendovascular procedures. However, the experience with TRA in neuroangiography is still in early stages in most centers, and the safety and feasibility of this approach have not been well established. The purpose of this study is to report the safety and feasibility of TRA for neuroendovascular procedures.MethodsWe reviewed charts from six institutions in the USA to include consecutive patients who underwent diagnostic or interventional neuroendovascular procedures through TRA from July 2018 to July 2019. Collected data included baseline characteristics, procedural variables, complications, and whether there was a crossover to transfemoral access.ResultsA total of 2203 patients were included in the study (age 56.1±15.2, 60.8% women). Of these, 1697 (77%) patients underwent diagnostic procedures and 506 (23%) underwent interventional procedures. Successfully completed procedures included aneurysm coiling (n=97), flow diversion (n=89), stent-assisted coiling (n=57), balloon-assisted coiling (n=19), and stroke thrombectomy (n=76). Crossover to femoral access was required in 114 (5.2%). There were no major complications related to the radial access site. Minor complications related to access site were seen in 14 (0.6%) patients.ConclusionIn this early stage of transforming to the ‘radial-first’ approach for neuroendovascular procedures, TRA was safe with low complication rates for both diagnostic and interventional procedures. A wide range of procedures were completed successfully using TRA.

Paget-Schroetter syndrome (PSS) is a primary upper extremity deep vein thrombosis (DVT) that occurs with no significant risk factors, mostly in a young and healthy patient. Treatment of this disease is discussed heavily in the literature and the optimal treatment method is still being debated. Here, we present a patient with PSS treated with balloon angioplasty, thrombolysis and treatment with an oral thrombin inhibitor (apixaban) who developed recurrence of PSS. A 38-year-old white male with no past medical history, presented to an urgent care center with sudden onset axillary pain and an axillary lump that was treated with outpatient antibiotics. Extensive deep venous thrombosis was diagnosed with computed tomography (CT) and ultrasound. He underwent percutaneous pharmacomechanical thrombectomy. Postprocedural angiogram showed significant improvement in the caliber of the axillary and subclavian veins where they crossed the first rib. He was discharged on apixaban and underwent removal of his first rib 1 month later. He returned 3 weeks later with recurrence of right arm pain and swelling. Repeat ultrasound showed thrombus in the right arm and venogram confirmed 80% stenosis at the subclavian vein as it enters the innominate vein. He was again treated with placement of a thrombolytic catheter and overnight thrombolysis of the central venous circulation on the right-side upper extremity balloon angioplasty of the subclavian vein, axillary vein, and basilic vein. He is disease-free for 6 months. Recurrence of PSS after surgical removal of rib, thrombectomy, thrombolysis while using apixaban is very rare. This is the first case to our knowledge presented with recurrent PSS treated with apixaban, early rib resection, balloon angioplasty and thrombectomy.

IntroductionTransradial access is increasingly used among neurointerventionalists as an alternative to the transfemoral route. Currently available data, building on the interventional cardiology experience, primarily focus on right radial access. However, there are clinical scenarios when left-sided access may be indicated. The purpose of this study was to evaluate the technical feasibility of left transradial access to cerebral angiography across three institutions.MethodsA retrospective chart review was performed for patients who underwent cerebral angiography accessed via the left radial artery at three institutions between January 2018 and July 2019. The outcome variables studied were successful catheterization, vascular complications, and fluoroscopic time.ResultsNineteen patients underwent a total of 25 cerebral angiograms via left transradial access for cerebral aneurysms (n=15), basilar occlusion (n=1), carotid stenosis (n=1), arteriovenous malformation (n=1), and cervical neurofibroma (n=1). There were 12 diagnostic angiograms and 13 interventional angiograms. The left transradial approach was chosen due to left vertebrobasilar pathology (n=22), right subclavian stenosis (n=2), and previous right arm amputation (n=1). There was one instance of radial artery spasm, which resolved after catheter removal, and one conversion to transfemoral access in an interventional case due to lack of distal catheter support. There were no procedural complications.ConclusionsLeft transradial access in diagnostic and interventional cerebral angiography is a technically feasible, safe, and an effective alternative when indicated, and may be preferable for situations in which pathology locations or anatomic limitations preclude right-sided radial access.

Abnormal cerebrospinal fluid (CSF) flow is associated with a variety of poorly understood neurological disorders such as Alzheimer's Disease and hydrocephalus. The lack of comprehensive understanding of the fluid and solid mechanics of CSF flow remains a critical barrier in the development of diagnostic assessment and potential treatment options for these diseases. We have developed a whole brain, patient-specific computational fluid dynamics (CFD) simulation of CSF flow in the cranial cavity as a step towards comprehensive understanding of CSF dynamics and how they relate to neurodegenerative diseases.A patient-specific 3D geometry of the CSF filled spaces was segmented from structural MRI. Patient-specific boundary conditions were measured using phase contrast MRI. A rigid wall three-dimensional CFD simulation was conducted using only patient-specific waveforms as boundary conditions. Deformation of brain tissue is accounted for using volumetric flowrate boundary conditions calculated via the conservation of mass. Phase contrast MRI measurement of maximum velocity at the cerebral aqueduct was used to validate the simulation with excellent agreement.The CSF dynamics across the cardiac cycle are presented, illustrating the relationship between arterial flow and CSF flow. Flow in and out of the ventricles was shown to have a slight phase delay (∼20 % of the cardiac cycle) from flow in the subarachnoid space. Intracranial pressure dynamics are presented, with pressure in the Lateral Ventricles demonstrating less significant transient effects than pressure in the subarachnoid space.This work presents a quantitatively validated whole-brain simulation of CSF flow for a single healthy subject. The computational methodology improves over the state of the art by eliminating non-physiological boundary conditions and unnecessary assumptions about the mechanical properties of brain tissue, providing an essential step towards clinically useful tools for assessing the development of neurodegenerative disorders.

In this case report, we describe bilateral endoscopic intracerebral hemorrhage (ICH) evacuations in patients presenting on temporally distinct occasions with separate, contralateral lesions. Two patients presented with spontaneous right-sided ICH and underwent endoscopic evacuations. Both patients achieved some degree of functional improvement postoperatively. Each patient then experienced a second ICH in the left hemisphere months later, and again underwent endoscopic evacuation of the contralateral lesion. Postoperatively, both patients faced significantly longer hospitalizations and severe drops in functional independence compared to the first surgery. Functional outcomes after contralateral endoscopic ICH evacuation may vary significantly, and bilateral disease portends a worse prognosis.

Background A significant proportion of transfemoral cerebral angiography complications are related to the access site, with no clear consensus concerning the optimal closure technique. In this study, we examined the usefulness of a shortened closure protocol for transfemoral diagnostic cerebral angiography. Methods We performed a retrospective review of patients who underwent transfemoral (4Fr sheath) diagnostic cerebral angiography procedures at our institution. We included patients > 18 years old who underwent the shortened closure protocol to achieve hemostasis at the access site. The shortened protocol entailed the use of nonocclusive manual compression for 15 min followed by 2 h of bed rest, with additional 10–15 min of compression for new hematoma. We collected and analyzed the patients’ demographics, use of antiplatelet and anticoagulation medications, sheath size, and others. Results The study cohort comprised 119 patients with a mean age was 54 years with (88%) females. Forty-one patients (34%) were on antiplatelet medications, with 12 (10%) on dual antiplatelet therapy (DAPT). Four patients (3%) (two on DAPT, one on Aspirin alone, and one was not on any antiplatelet medication) had access site hematoma that required additional compression. Subgroup analysis showed that within the DAPT, Aspirin alone, and no antiplatelet medications groups, (17%), (3%), and (1%) of patients developed access site hematoma, respectively. Conclusion This pilot study demonstrates that our closure protocol for transfemoral angiograms is safe and effective. There was a trend toward higher access-site complications in patients on DAPT. Further studies are required to expand on and validate our results.

BackgroundMost intracranial stents contain nickel alloy, and nickel allergy or hypersensitivity is common. Neurological injury following endovascular treatment with a nickel containing intracranial stent has been reported in patients with purported nickel allergy, but it is unclear whether these reactions represent true nickel hypersensitivity. We quantified nickel release from commonly used intracranial stents to investigate whether such stents should be avoided in patients with nickel allergy.MethodsWe examined nickel release from seven commonly used intracranial stents: Enterprise, LVIS Jr, Neuroform, Wingspan, Zilver, Pipeline Flex Embolization Device, and Surpass Evolve. We incubated each stent in human plasma-like media for 30 days. Dimethylglyoxime (DMG) spot testing was performed on each stent to detect released nickel at 0 and 30 days. Inductively coupled plasma–optical emission spectroscopy (ICP-OES) was then used to quantify the nickel concentration of the media at 30 days. Nickel currency and nickel standard for atomic absorption spectrometry were used as positive controls.ResultsDMG spot tests indicated nickel release only from nickel currency at 0 and 30 days of incubation. No nickel release was detected from any stent at 30 days using ICP-OES.ConclusionsNickel release from commonly used intracranial stents is negligible. These results suggest that previously reported hypersensitivity to these stents may be misattributed to nickel allergy, and that patients with nickel allergy may be safely treated with select nickel-containing stents.

The flow in a spherical cavity on a curved round pipe is a canonical flow that describes well the flow inside a sidewall aneurysm on an intracranial artery. Intracranial aneurysms are often treated with a flow-diverting stent (FDS), a low-porosity metal mesh that covers the entrance to the cavity, to reduce blood flow into the aneurysm sac and exclude it from mechanical stresses imposed by the blood flow. Successful treatment is highly dependent on the degree of reduction of flow inside the cavity, and the resulting altered fluid mechanics inside the aneurysm following treatment. Using stereoscopic particle image velocimetry, we characterize the fluid mechanics in a canonical configuration representative of an intracranial aneurysm treated with a FDS: a spherical cavity on the side of a curved round pipe covered with a metal mesh formed by an actual medical FDS. This porous mesh coverage is the focus of Part 2 of the paper, characterizing the effects of parent vessel Re, De and pulsatility, Wo, on the fluid dynamics, compared with the canonical configuration with no impediments to flow into the cavity that is described in Part 1 (Chassagne et al., J. Fluid Mech., vol. 915, 2021, A123). Coverage with a FDS markedly reduces the flow Re in the aneurysmal cavity, creating a viscous-dominated flow environment despite the parent vessel Re > 100. Under steady flow conditions, the topology that forms inside the cavity is shown to be a function of the parent vessel De. At low values of De, flow enters the cavity at the leading edge and remains attached to the wall before exiting at the trailing edge, a novel behaviour that was not found under any conditions of the high-Re, unimpeded cavity flow described in Part 1. Under these conditions, flow in the cavity co-rotates with the direction of the free-stream flow, similar to Stokes flow in a cavity. As De increases, the flow along the leading edge begins to separate, and the recirculation zone grows with increasing De, until, above De ≈ 180, the flow inside the cavity is fully recirculating, counter-rotating with respect to the free-stream flow. Under pulsatile flow conditions, the vortex inside the cavity progresses through the same cycle - switching from attached and co-rotating with the free-stream flow at the beginning of the cycle (low velocity and positive acceleration) to separated and counter-rotating as De reaches a critical value. The location of separation within the harmonic cycle is shown to be a function of both De and Wo. The values of aneurysmal cavity Re based on both the average velocity and the circulation inside the cavity are shown to increase with increasing values of De, while Wo is shown to have little influence on the time-averaged metrics. As De increases, the strength of the secondary flow in the parent vessel grows, due to the inertial instability in the curved pipe, and the flow rate entering the cavity increases. Thus, the effectiveness of FDS treatment to exclude the aneurysmal cavity from the haemodynamic stresses is compromised for aneurysms located on high-curvature arteries, i.e. vessels with high De, and this can be a fluid mechanics criterion to guide treatment selection.

ImportanceThere is substantial controversy with regards to the adequacy and use of noncontrast head computed tomography (NCCT) for late-window acute ischemic stroke in selecting candidates for mechanical thrombectomy.ObjectiveTo assess clinical outcomes of patients with acute ischemic stroke presenting in the late window who underwent mechanical thrombectomy stratified by NCCT admission in comparison with selection by CT perfusion (CTP) and diffusion-weighted imaging (DWI).Design, Setting, and ParticipantsIn this multicenter retrospective cohort study, prospectively maintained Stroke Thrombectomy and Aneurysm (STAR) database was used by selecting patients within the late window of acute ischemic stroke and emergent large vessel occlusion from 2013 to 2021. Patients were selected by NCCT, CTP, and DWI. Admission Alberta Stroke Program Early CT Score (ASPECTS) as well as confounding variables were adjusted. Follow-up duration was 90 days. Data were analyzed from November 2021 to March 2022.ExposuresSelection by NCCT, CTP, or DWI.Main Outcomes and MeasuresPrimary outcome was functional independence (modified Rankin scale 0-2) at 90 days.ResultsAmong 3356 patients, 733 underwent late-window mechanical thrombectomy. The median (IQR) age was 69 (58-80) years, 392 (53.5%) were female, and 449 (65.1%) were White. A total of 419 were selected with NCCT, 280 with CTP, and 34 with DWI. Mean (IQR) admission ASPECTS were comparable among groups (NCCT, 8 [7-9]; CTP, 8 [7-9]; DWI 8, [7-9]; P = .37). There was no difference in the 90-day rate of functional independence (aOR, 1.00; 95% CI, 0.59-1.71; P = .99) after adjusting for confounders. Symptomatic intracerebral hemorrhage (NCCT, 34 [8.6%]; CTP, 37 [13.5%]; DWI, 3 [9.1%]; P = .12) and mortality (NCCT, 78 [27.4%]; CTP, 38 [21.1%]; DWI, 7 [29.2%]; P = .29) were similar among groups.Conclusions and RelevanceIn this cohort study, comparable outcomes were observed in patients in the late window irrespective of neuroimaging selection criteria. Admission NCCT scan may triage emergent large vessel occlusion in the late window.

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

Computational fluid dynamics (CFD) has been used to evaluate the efficiency of endovascular treatment in coiled cerebral aneurysms. The explicit geometry of the coil mass cannot typically be incorporated into CFD simulations since the coil mass cannot be reconstructed from clinical images due to its small size and beam hardening artifacts. The existing methods use imprecise porous medium representations. We propose a new porous model taking into account the porosity heterogeneity of the coils deployed in the aneurysm.The porosity heterogeneity of the coil mass deployed inside two patients' cerebral aneurysm phantoms is first quantified based on 3D X-ray synchrotron images. These images are also used to compute the permeability and the inertial factor arising in porous models. A new homogeneous porous model (porous crowns model), considering the coil's heterogeneity, is proposed to recreate the flow within the coiled aneurysm. Finally, the validity of the model is assessed through comparisons with coil-resolved simulations.The strong porosity gradient of the coil measured close to the aneurysmal wall is well captured by the porous crowns model. The permeability and the inertial factor values involved in this model are closed to the ideal homogeneous porous model leading to a mean velocity in the aneurysmal sac similar as in the coil-resolved model.The porous crowns model allows for an accurate description of the mean flow within the coiled cerebral aneurysm.

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

ObjectiveThe goal of this article is to provide recommendations for the early career neurointerventionalist in writing a successful grant application to the National Institutes of Health (NIH) and similar funding agencies.MethodsThe authors reviewed NIH rules and regulations and also reflected on their own collective experience in writing NIH grant proposals in the area of cerebrovascular disease and neurointerventional surgery.ResultsA strong proposal should address an important scientific problem where there is a gap in knowledge. The solution offered needs to be innovative but at the same time based on a strong scientific premise. The proposed research must be feasible to implement and investigate in the researcher’s environment.ConclusionSuccessful grant writing is critical in funding and enhancing research. The information in the article may aid in the preparation stage of grant writing for early career neurointerventionalists.

BackgroundAnterior cranial fossa dural arteriovenous fistulas (ACF-dAVFs) are aggressive vascular lesions. The pattern of venous drainage is the most important determinant of symptoms. Due to the absence of a venous sinus in the anterior cranial fossa, most ACF-dAVFs have some degree of drainage through small cortical veins. We describe the natural history, angiographic presentation and outcomes of the largest cohort of ACF-dAVFs.MethodsThe CONDOR consortium includes data from 12 international centers. Patients included in the study were diagnosed with an arteriovenous fistula between 1990–2017. ACF-dAVFs were selected from a cohort of 1077 arteriovenous fistulas. The presentation, angioarchitecture and treatment outcomes of ACF-dAVF were extracted and analyzed.Results60 ACF-dAVFs were included in the analysis. Most ACF-dAVFs were symptomatic (38/60, 63%). The most common symptomatic presentation was intracranial hemorrhage (22/38, 57%). Most ACF-dAVFs drained through cortical veins (85%, 51/60), which in most instances drained into the superior sagittal sinus (63%, 32/51). The presence of cortical venous drainage predicted symptomatic presentation (OR 9.4, CI 1.98 to 69.1, p=0.01). Microsurgery was the most effective modality of treatment. 56% (19/34) of symptomatic patients who were treated had complete resolution of symptoms. Improvement of symptoms was not observed in untreated symptomatic ACF-dAVFs.ConclusionMost ACF-dAVFs have a symptomatic presentation. Drainage through cortical veins is a key angiographic feature of ACF-dAVFs that accounts for their malignant course. Microsurgery is the most effective treatment. Due to the high risk of bleeding, closure of ACF-dAVFs is indicated regardless of presentation.

OBJECTIVE Seizures are the second most common presenting symptom of brain arteriovenous malformations (bAVMs) after hemorrhage. Risk factors for preoperative seizures and subsequent seizure control outcomes have been well studied. There is a paucity of literature on postoperative, de novo seizures in initially seizure-naïve patients who undergo resection. Whereas this entity has been documented after craniotomy for a wide variety of neurosurgically treated pathologies including tumors, trauma, and aneurysms, de novo seizures after bAVM resection are poorly studied. Given the debilitating nature of epilepsy, the purpose of this study was to elucidate the incidence and risk factors associated with de novo epilepsy after bAVM resection. METHODS A retrospective review of patients who underwent resection of a bAVM over a 15-year period was performed. Patients who did not present with seizure were included, and the primary outcome was de novo epilepsy (i.e., a seizure disorder that only manifested after surgery). Demographic, clinical, and radiographic characteristics were compared between patients with and without postoperative epilepsy. Subgroup analysis was conducted on the ruptured bAVMs. RESULTS From a cohort of 198 patients who underwent resection of a bAVM during the study period, 111 supratentorial ruptured and unruptured bAVMs that did not present with seizure were included. Twenty-one patients (19%) developed de novo epilepsy. One-year cumulative rates of developing de novo epilepsy were 9% for the overall cohort and 8.5% for the cohort with ruptured bAVMs. There were no significant differences between the epilepsy and no-epilepsy groups overall; however, the de novo epilepsy group was younger in the cohort with ruptured bAVMs (28.7 ± 11.7 vs 35.1 ± 19.9 years; p = 0.04). The mean time between resection and first seizure was 26.0 ± 40.4 months, with the longest time being 14 years. Subgroup analysis of the ruptured and endovascular embolization cohorts did not reveal any significant differences. Of the patients who developed poorly controlled epilepsy (defined as Engel class III–IV), all had a history of hemorrhage and half had bAVMs located in the temporal lobe. CONCLUSIONS De novo epilepsy after bAVM resection occurs at an annual cumulative risk of 9%, with potentially long-term onset. Younger age may be a risk factor in patients who present with rupture. The development of poorly controlled epilepsy may be associated with temporal lobe location and a delay between hemorrhage and resection.

BACKGROUND: Low-grade intracranial dural arteriovenous fistulas (dAVF) have a benign natural history in the majority of cases. The benefit from treatment of these lesions is controversial.OBJECTIVE: To compare the outcomes of observation versus intervention for low-grade dAVFs.METHODS: We retrospectively reviewed dAVF patients from institutions participating in the CONsortium for Dural arteriovenous fistula Outcomes Research (CONDOR). Patients with low-grade (Borden type I) dAVFs were included and categorized into intervention or observation cohorts. The intervention and observation cohorts were matched in a 1:1 ratio using propensity scores. Primary outcome was modified Rankin Scale (mRS) at final follow-up. Secondary outcomes were excellent (mRS 0-1) and good (mRS 0-2) outcomes, symptomatic improvement, mortality, and obliteration at final follow-up.RESULTS: The intervention and observation cohorts comprised 230 and 125 patients, respectively. We found no differences in primary or secondary outcomes between the 2 unmatched cohorts at last follow-up (mean duration 36 mo), except obliteration rate was higher in the intervention cohort (78.5% vs 24.1%, P < .001). The matched intervention and observation cohorts each comprised 78 patients. We also found no differences in primary or secondary outcomes between the matched cohorts except obliteration was also more likely in the matched intervention cohort (P < .001). Procedural complication rates in the unmatched and matched intervention cohorts were 15.4% and 19.2%, respectively.CONCLUSION: Intervention for low-grade intracranial dAVFs achieves superior obliteration rates compared to conservative management, but it fails to improve neurological or functional outcomes. Our findings do not support the routine treatment of low-grade dAVFs.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes a systemic disease that affects nearly all organ systems through infection and subsequent dysregulation of the vascular endothelium. One of the most striking phenomena has been a coronavirus disease 2019 (COVID-19)-associated coagulopathy. Given these findings, questions naturally emerged about the prothrombotic impact of COVID-19 on cerebrovascular disease and whether ischemic stroke is a clinical feature specific to COVID-19 pathophysiology. Early reports from China and several sites in the northeastern United States seemed to confirm these suspicions. Since these initial reports, many cohort studies worldwide observed decreased rates of stroke since the start of the pandemic, raising concerns for a broader impact of the pandemic on stroke treatment. In this review, we provide a comprehensive assessment of how the pandemic has affected stroke presentation, epidemiology, treatment, and outcomes to better understand the impact of COVID-19 on cerebrovascular disease. Much evidence suggests that this decline in stroke admissions stems from the global response to the virus, which has made it more difficult for patients to get to the hospital once symptoms start. However, there does not appear to be a demonstrable impact on quality metrics once patients arrive at the hospital. Despite initial concerns, there is insufficient evidence to ascribe a causal relationship specific to the pathogenicity of SARS-CoV-2 on the cerebral vasculature. Nevertheless, when patients infected with SARS-CoV-2 present with stroke, their presentation is likely to be more severe, and they have a markedly higher rate of in-hospital mortality than patients with either acute ischemic stroke or COVID-19 alone.

Introduced into the human population in December 2019, the zoonotic novel β-coronavirus spread rapidly. Labeled Coronavirus Disease 2019 (COVID-19) by the World Health Organization (WHO), the infection reached pandemic proportions by March 11, 2020. At the time of writing this commentary, globally our way of life is transforming. Hospitals are no exception, with mobilization into an emergency mode including halting all non-urgent elective procedures and clinic visits. The Centers for Disease Control and Prevention (CDC) and the WHO are currently recommending aggressive measures to prevent viral transmission. For healthcare workers, aside from standard precautions like using personal protective equipment (PPE) and handwashing, these bodies are strongly encouraging the practice of ‘social distancing’ (SD) and ‘self-quarantine’ (SQ) for those with suspected or proven infections. In essence, SD means avoiding crowds, closing schools, canceling all social events and meetings, and maintaining a 6-foot distance between individuals. SQ refers to isolating oneself for 2 weeks without any social contact to avoid transmission. These efforts will be critical to mitigating covid-19 spread, as they may ‘flatten the curve’ of new and serious cases and prevent the healthcare system from being overwhelmed. Healthcare workers are on the front line, and doctors, nurses, and hospital staff are at highest risk of contracting the virus. As cases become ubiquitous throughout the healthcare system, many staff will become secondarily infected and will require medical treatment and SQ. As the volume of infected personnel increases, many services will need to operate on a skeleton crew. If infection breaches a critical threshold, some emergency services may cease to be possible. The greatest potential impact will be on mechanical thrombectomy (MT) in acute ischemic stroke. MT for emergent large vessel occlusion (ELVO) represents one of the most impactful and effective emergent interventions in medicine,1 markedly reducing morbidity and mortality. MT is …

Flow-diverting stents (FDS) are used to treat cerebral aneurysms. They promote the formation of a stable thrombus within the aneurysmal sac and, if successful, isolate the aneurysmal dome from mechanical stresses to prevent rupture. Platelet activation, a mechanism necessary for thrombus formation, is known to respond to biomechanical stimuli, particularly to the platelets’ residence time and shear stress exposure. Currently, there is no reliable method for predicting FDS treatment outcomes, either a priori or after the procedure. Eulerian computational fluid dynamic (CFD) studies of aneurysmal flow have searched for predictors of endovascular treatment outcome; however, the hemodynamics of thrombus formation cannot be fully understood without considering the platelets’ trajectories and their mechanics-triggered activation. Lagrangian analysis of the fluid mechanics in the aneurysmal vasculature provides novel metrics by tracking the platelets’ residence time (RT) and shear history (SH). Eulerian and Lagrangian parameters are compared for 19 patient-specific cases, both pre- and post-treatment, to assess the degree of change caused by the FDS and subsequent treatment efficacy.

BackgroundUse of the radial artery as an access site for neurointerventional procedures is gaining popularity after several studies in interventional cardiology have demonstrated superior patient safety, decreased length of stay, and patient preference compared with femoral artery access. The transradial approach has yet to be characterized for intraoperative cerebral angiography.ObjectiveTo report a multicenter experience on the use of radial artery access in intraoperative cerebral angiography, including case series and discussion of technical nuances.Methods27 patients underwent attempted transradial cerebral angiography betweenMay 2017 and May 2019. Data were collected regarding technique, patient positioning, vessels selected, technical success rate, and access site complications.Results24 of the 27 patients (88.8%) underwent successful transradial intraoperative cerebral angiography. 18 patients (66.7%) were positioned supine, 6 patients (22.2%) were positioned prone, 1 patient (3.7%) was positioned lateral, and 2 patients (7.4%) were positioned three-quarters prone. A total of 31 vessels were selected including 13 right carotid arteries (8 common, 1 external, 4 internal), 11 left carotid arteries (9 common and 2 internal), and 6 vertebral arteries (5 right and 1 left). Two patients (7.4%) required conversion to femoral access in order to complete the intraoperative angiogram (1 due to arterial vasospasm and 1 due to inadvertent venous catheterization). One procedure (3.7%) was aborted because of inability to obtain the appropriate fluoroscopic views due to patient positioning. No patient experienced stroke, arterial dissection, or access site complication.ConclusionsTransradial intraoperative cerebral angiography is safe and feasible with potential for improved operating room workflow ergonomics, faster patient mobility in the postoperative period, and reduced costs.

BackgroundPediatric acute ischemic stroke with underlying large vessel occlusion is a rare disease with significant morbidity and mortality. There is a paucity of data about the safety and outcomes of endovascular thrombectomy in these cases, especially with modern devices.MethodsWe conducted a retrospective review of all pediatric stroke patients who underwent endovascular thrombectomy in nine US tertiary centers between 2008 and 2017.ResultsNineteen patients (63.2% male) with a mean (SD) age of 10.9(6) years and weight 44.6 (30.8) kg were included. Mean (SD) NIH Stroke Scale (NIHSS) score at presentation was 13.9 (5.7). CT-based assessment was obtained in 88.2% of the patients and 58.8% of the patients had perfusion-based assessment. All procedures were performed via the transfemoral approach. The first-pass device was stentriever in 52.6% of cases and aspiration in 36.8%. Successful revascularization was achieved in 89.5% of the patients after a mean (SD) of 2.2 (1.5) passes, with a mean (SD) groin puncture to recanalization time of 48.7 (37.3) min (median 41.5). The mean (SD) reduction in NIHSS from admission to discharge was 10.2 (6.2). A good neurological outcome was achieved in 89.5% of the patients. One patient had post-revascularization seizure, but no other procedural complications or mortality occurred.ConclusionsEndovascular thrombectomy is safe and feasible in selected pediatric patients. Technical and neurological outcomes were comparable to adult literature with no safety concerns with the use of standard adult devices in patients as young as 18 months. This large series adds to the growing literature but further studies are warranted.

International audience; Perianeurysmal hemodynamics play a vital role in the initiation, growth and rupture of intracranial aneurysms. In vitro investigations of aneurysmal hemodynamics are helpful to visualize and measure blood flow, and aiding surgical planning approaches. Improving in vitro model creation can improve the feasibility and accuracy of hemodynamic investigations and surgical planning, improving clinical value. In this study, in vitro models were created from three-dimensional rotational angiography (3DRA) of six patients harboring intracranial aneurysms using a multi-step process involving 3D printing, index of refraction matching and silicone casting that renders the models transparent for flow visualization. Each model was treated with the same commercially-available, patient-specific, endovascular devices (coils and/or stents). All models were scanned by synchrotron X-ray microtomography to obtain high-resolution imaging of the vessel lumen, aneurysmal sac and endovascular devices. Dimensional accuracy was compared by quantifying the differences between the microtomographic reconstructions of the fabricated phantoms and the original 3DRA obtained during patient treatment. True-scale in vitro flow phantoms were successfully created for all six patients. Optical transparency was verified by using an index of refraction matched working fluid that replicated the mechanical behavior of blood. Synchrotron imaging of vessel lumen, aneurysmal sac and endovascular devices was successfully obtained, and dimensional errors were found to be O(100 μm). The creation of dimensionally-accurate, optically-transparent flow phantoms of patient-specific intracranial aneurysms is feasible using 3D printing technology. Such models may enable in vitro investigations of aneurysmal hemodynamics to aid in treatment planning and outcome prediction to devise optimal patient-specific neurointerventional strategies.

In recent years the use of immunomodulating therapy to treat various cancers has been on the rise. Three checkpoint inhibitors have been approved by the Food and Drug Administration (ipilimumab, pembrolizumab and nivolumab). The use of these drugs comes with serious adverse events related to excessive immune activation, collectively known as immune-related adverse events (irAEs). We conducted a system-based review of 139 case reports/case series that have described these adverse events between January 2016 and April 2018, found in the PubMed database. There was a broad spectrum of presentations, doses and checkpoint inhibitors used. The most common check point inhibitor observed in our literature review was nivolumab. The most common adverse effects encountered were colitis (14/139), hepatitis (11/139), adrenocorticotropic hormone insufficiency (12/139), hypothyroidism (7/139), type 1 diabetes (22/139), acute kidney injury (16/139) and myocarditis (10/139). The treatment most commonly consisted of cessation of the immune checkpoint inhibitor, initiation of steroids and supportive therapy. This approach provided a complete resolution in a majority of cases; however, there were many that developed long-term adverse events with deaths reported in a few cases. The endocrine system was the mostly commonly affected with the development of type 1 diabetes mellitus or diabetic ketoacidosis being the most frequently reported adverse events. While immunomodulating therapy is a significant advance in the management of various malignancies, it is capable of serious adverse effects. Because the majority of the cases developed pancreatic dysfunction within five cycles of therapy, in addition to the evaluation of other systems, pancreatic function should be closely monitored to minimize adverse impact on patients.

Background Middle meningeal artery (MMA) embolization is an apparently efficacious minimally invasive treatment for nonacute subdural hematomas (NASHs), but how different embolisates affect outcomes remains unclear. Our objective was to compare radiographic and clinical outcomes after particle or liquid MMA embolization. Methods Patients who had MMA embolization for NASH were retrospectively identified from a multi-institution database. The primary radiographic and clinical outcomes—50% NASH thickness reduction and need for surgical retreatment within 90 days, respectively—were compared for liquid and particle embolizations in patients treated 1) without surgical intervention (upfront), 2) after recurrence, or 3) with concomitant surgery (prophylactic). Results The upfront, recurrent, and prophylactic subgroups included 133, 59, and 16 patients, respectively. The primary radiographic outcome was observed in 61.8%, 61%, and 72.7% of particle-embolized patients and 61.3%, 55.6%, and 20% of liquid-embolized patients, respectively (p = 0.457, 0.819, 0.755). Hazard ratios comparing time to reach radiographic outcome in the particle and liquid groups or upfront, recurrent, andprophylactic timing were 1.31 (95% CI 0.78–2.18; p = 0.310), 1.09 (95% CI 0.52–2.27; p = 0.822), and 1.5 (95% CI 0.14–16.54; p = 0.74), respectively. The primary clinical outcome occurred in 8.0%, 2.4%, and 0% of patients who underwent particle embolization in the upfront, recurrent, and prophylactic groups, respectively, compared with 0%, 5.6%, and 0% who underwent liquid embolization (p = 0.197, 0.521, 1.00). Conclusions MMA embolization with particle and liquid embolisates appears to be equally effective in treatment of NASHs as determined by the percentage who reach, and the time to reach, 50% NASH thickness reduction and the incidence of surgical reintervention within 90 days.

Objective: To evaluate the association of CT/CT angiography (CTA) findings and clinical characteristics with subsequent vasospasm in patients with aneurysmal subarachnoid hemorrhage (aSAH). Methods-: Consecutive presentation CTA head exams in patients with aSAH between January 2005 and June 2015 were retrospectively evaluated for intracranial arterial calcification, undulation and non-calcified stenosis. Additional variables including modified Fisher Scale (mFS), Glasgow Coma Scale (GCS) and neurological exam status were reviewed. Associations of CTA findings with the incidence of angiographic vasospasm were assessed with multivariate logistic regression models using the least absolute shrinkage and selection operator machine-learning algorithm. Model performance was summarized using c-index with bootstrap optimism-adjustment. Results Intracranial arterial calcification, seen in 51.7% of 195 total patients, was protective against vasospasm (OR-0.6; 95% CI-0.52–0.67; p = 0.009), while arterial undulation (24%) was associated with subsequent vasospasm (OR-2.6; 95% CI-1.3–5.1; p = 0.007). Non-calcified intracranial arterial stenosis (5%) was associated with subsequent vasospasm, (OR-4.7; 95% CI-1.0–22.8; p = 0.054). Least absolute shrinkage and selection operator selected all three CTA findings as predictors in a multivariate model for vasospasm in addition to clinical factors, which demonstrated superior predictive performance (c-index-0.74; 95% CI-0.69–0.82) compared to a model based on mFS and clinical factors only (c-index-0.66; 95% CI-0.57–0.75; p = 0.010 for the difference). Conclusion: Presentation CTA findings combined with clinical factors may better predict the development of vasospasm in patients with aSAH compared to current prognostic models alone. Advances in knowledge: The combination of initial CT/CTA and clinical findings better predict development of vasospasm after aSAH. This can lead to better markers for use in future clinical trials to develop vasospasm preventative treatments and potentially provide better targets for early aggressive treatment.