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Background and purpose Previous studies suggest that mechanisms and outcomes in patients with COVID-19-associated stroke differ from those in patients with non-COVID-19-associated strokes, but there is limited comparative evidence focusing on these populations. The aim of this study, therefore, was to determine if a significant association exists between COVID-19 status with revascularization and functional outcomes following thrombectomy for large vessel occlusion (LVO), after adjustment for potential confounding factors. Methods A cross-sectional, international multicenter retrospective study was conducted in consecutively admitted COVID-19 patients with concomitant acute LVO, compared to a control group without COVID-19. Data collected included age, gender, comorbidities, clinical characteristics, details of the involved vessels, procedural technique, and various outcomes. A multivariable-adjusted analysis was conducted. Results In this cohort of 697 patients with acute LVO, 302 had COVID-19 while 395 patients did not. There was a significant difference (p < 0.001) in the mean age (in years) and gender of patients, with younger patients and more males in the COVID-19 group. In terms of favorable revascularization (modified Thrombolysis in Cerebral Infarction [mTICI] grade 3), COVID-19 was associated with lower odds of complete revascularization (odds ratio 0.33, 95% confidence interval [CI] 0.23-0.48; p < 0.001), which persisted on multivariable modeling with adjustment for other predictors (adjusted odds ratio 0.30, 95% CI 0.12-0.77; p = 0.012). Moreover, endovascular complications, in-hospital mortality, and length of hospital stay were significantly higher among COVID-19 patients (p < 0.001). Conclusion COVID-19 was an independent predictor of incomplete revascularization and poor functional outcome in patients with stroke due to LVO. Furthermore, COVID-19 patients with LVO were more often younger and had higher morbidity/mortality rates.

Histotripsy has been previously applied to target various cranial locations in vitro through an excised human skull. Recently, a transcranial magnetic resonance (MR)-guided histotripsy (tcMRgHt) system was developed, enabling pre-clinical investigations of tcMRgHt for brain surgery. To determine the feasibility of in vivo transcranial histotripsy, tcMRgHt treatment was delivered to eight pigs using a 700-kHz, 128-element, MR-compatible phased-array transducer inside a 3-T magnetic resonance imaging (MRI) scanner. After craniotomy to open an acoustic window to the brain, histotripsy was applied through an excised human calvarium to target the inside of the pig brain based on pre-treatment MRI and fiducial markers. MR images were acquired pre-treatment, immediately post-treatment and 2–4 h post-treatment to evaluate the acute treatment outcome. Successful histotripsy ablation was observed in all pigs. The MR-evident lesions were well confined within the targeted volume, without evidence of excessive brain edema or hemorrhage outside of the target zone. Histology revealed tissue homogenization in the ablation zones with a sharp demarcation between destroyed and unaffected tissue, which correlated well with the radiographic treatment zones on MRI. These results are the first to support the in vivo feasibility of tcMRgHt in the pig brain, enabling further investigation of the use of tcMRgHt for brain surgery.

OBJECTIVE Despite advancement of thrombectomy technologies for large-vessel occlusion (LVO) stroke and increased user experience, complete recanalization rates linger around 50%, and one-third of patients who have undergone successful recanalization still experience poor neurological outcomes. To enhance the understanding of the biomechanics and failure modes, the authors conducted an experimental analysis of the interaction of emboli/artery/devices in the first human brain test platform for LVO stroke described to date. METHODS In 12 fresh human brains, 105 LVOs were recreated by embolizing engineered emboli analogs and recanalization was attempted using aspiration catheters and/or stent retrievers. The complex mechanical interaction between diverse emboli (elastic, stiff, and fragment prone), arteries (anterior and posterior circulation), and thrombectomy devices were observed, analyzed, and categorized. The authors systematically evaluated the recanalization process through failure modes and effects analysis, and they identified where and how thrombectomy devices fail and the impact of device failure. RESULTS The first-pass effect (34%), successful (71%), and complete (60%) recanalization rates in this model were consistent with those in the literature. Failure mode analysis of 184 passes with thrombectomy devices revealed the following. 1) Devices loaded the emboli with tensile forces leading to elongation and intravascular fragmentation. 2) In the presence of anterograde flow, small fragments embolize to the microcirculation and large fragments result in recurrent vessel occlusion. 3) Multiple passes are required due to recurrent (15%) and residual (73%) occlusions, or both (12%). 4) Residual emboli remained in small branching and perforating arteries in cases of alleged complete recanalization (28%). 5) Vacuum caused arterial collapse at physiological pressures (27%). 6) Device withdrawal caused arterial traction (41%), and severe traction provoked avulsion of perforating and small branching arteries. CONCLUSIONS Biomechanically superior thrombectomy technologies should prevent unrestrained tensional load on emboli, minimize intraluminal embolus fragmentation and release, improve device/embolus integration, recanalize small branching and perforating arteries, prevent arterial collapse, and minimize traction.

Hydrocephalus is a common complication of aneurysmal subarachnoid hemorrhage (aSAH) that often requires acute placement of an external ventricular drain (EVD). The current systems available for determining which patients will require long-term cerebrospinal fluid diversion remain subjective. We investigated the ventricular volume change (ΔVV) after EVD clamping as an objective predictor of shunt dependence in patients with aSAH.We performed a retrospective medical record review and image analysis of patients treated for aSAH at a single academic institution who had required EVD placement for acute hydrocephalus and had undergone 1 EVD weaning trial. Head computed tomography (CT) scans obtained before and after EVD clamping were analyzed using a custom semiautomated MATLAB program (MathWorks, Natick, Massachusetts, USA), which segments each CT scan into 5 tissue types using k-means clustering. Differences in the pre- and postclamp ventricular volumes were calculated.A total of 34 patients with an indwelling shunt met the inclusion criteria and were sex- and age-matched to 34 controls without a shunt. The mean ΔVV was 19.8 mL in the shunt patients and 3.8 mL in the nonshunt patients (P 0.0001). The area under the receiver operating characteristic curve was 0.84. The optimal ΔVV threshold was 11.4 mL, with a sensitivity of 76.5% and specificity of 88.2% for predicting shunt dependence. The mean ΔVV was significantly greater for the patients readmitted for shunt placement compared with the patients not requiring cerebrospinal fluid diversion (18.69 mL vs. 3.84 mL; P = 0.005). Finally, 70% of the patients with delayed shunt dependence had ΔVV greater than the identified threshold.The ΔVV volume between head CT scans taken before and after EVD clamping was predictive of early and delayed shunt dependence.

Neurodiagnostic and neurointerventional radiology (NIR) play a central role in the diagnosis and treatment of skull base disorders. Noninvasive imaging modalities, including computed tomography and magnetic resonance imaging, are important in lesion localization, evaluation of lesion extent, and diagnosis, but cannot always be definitive. Image-guided skull base biopsy and percutaneous and endovascular treatment options are important tools in the diagnosis and treatment of head, neck, and skull base disorders. NIR plays an important role in the treatment of vascular disorders of the skull base. This article summarizes the imaging evaluation and interventional therapies pertinent to the skull base.

Background Appropriate thrombus-device interaction is critical for recanalization. Histology can serve as a proxy for mechanical properties, and thus inform technique selection. Objective To investigate the value of histologic characterization, we conducted a systematic review and meta-analysis on the relationship between thrombus histology and recanalization, technique, etiology, procedural efficiency, and imaging findings. Methods In this meta-analysis, we identified studies published between March 2010 and March 2020 reporting findings related to the histologic composition of thrombi in large vessel occlusion stroke. Studies with at least 10 patients who underwent mechanical thrombectomy using stent retriever or aspiration were considered. Only studies in which retrieved thrombi were histologically processed were included. Patient-level data were requested when data could not be directly extracted. The primary outcome assessed was the relationship between thrombus histology and angiographic outcome. Results A total of 22 studies encompassing 1623 patients met inclusion criteria. Clots associated with good angiographic outcome had higher red blood cell (RBC) content (mean difference [MD] 9.60%, 95% CI 3.85-15.34, P = .008). Thrombi retrieved by aspiration had less fibrin (MD -11.39, 95% CI -22.50 to -0.27, P = .046) than stent-retrieved thrombi. Fibrin/platelet-rich clots were associated with longer procedure times (MD 13.20, 95% CI 1.30-25.10, P = .037). Hyperdense artery sign was associated with higher RBC content (MD 14.17%, 95% CI 3.07-25.27, P = .027). No relationship was found between composition and etiology. Conclusion RBC-rich thrombi were associated with better recanalization outcomes and shorter procedure times, suggesting that preinterventional compositional characterization may yield important prognostic and therapeutic guidance.

Ehlers-Danlos type IV or vascular Ehlers-Danlos syndrome (vEDS) is a rare inherited disorder characterized by profound vascular fragility resulting from defective production of type III procollagen. Cerebrovascular pathologies including spontaneous dissections, cerebral aneurysms and cavernous-carotid fistulae are common. Endovascular therapies in this patient population are known to be higher risk, though many studies (pre-2000) involved older techniques and equipment. The purpose of this study is to investigate the safety and efficacy of modern neuro-endovascular techniques in the treatment of cerebrovascular pathologies in patients with vEDS.We combined a multi-institutional retrospective case series at three quaternary care centers with a systematic literature review of individual case reports and case series spanning 2000-2021 to evaluate the safety and efficacy of neuro-endovascular procedure in vEDS patients with cerebrovascular pathologies.Fifty-nine patients who underwent sixty-six neuro-endovascular procedures were evaluated. The majority of the patients had direct cavernous carotid fistulas (DCCF). Neuro-endovascular procedures had a 94% success rate with a complication rate of 30% and a mortality rate of 7.5%.Neuro-endovascular procedures can be done with a high rate of success in the treatment of cerebrovascular pathologies in patients with vEDS, though special care is required as complication and mortality rates are high. Access site and procedure-related vascular injuries remain a significant hurdle in treating vEDS with cerebrovascular pathologies, even with modern techniques.

BackgroundThe mechanisms and outcomes in coronavirus disease (COVID-19)-associated stroke are unique from those of non-COVID-19 stroke.ObjectiveTo describe the efficacy and outcomes of acute revascularization of large vessel occlusion (LVO) in the setting of COVID-19 in an international cohort.MethodsWe conducted an international multicenter retrospective study of consecutively admitted patients with COVID-19 with concomitant acute LVO across 50 comprehensive stroke centers. Our control group constituted historical controls of patients presenting with LVO and receiving a mechanical thrombectomy between January 2018 and December 2020.ResultsThe total cohort was 575 patients with acute LVO; 194 patients had COVID-19 while 381 patients did not. Patients in the COVID-19 group were younger (62.5 vs 71.2; P < .001) and lacked vascular risk factors (49, 25.3% vs 54, 14.2%; P = .001). Modified thrombolysis in cerebral infarction 3 revascularization was less common in the COVID-19 group (74, 39.2% vs 252, 67.2%; P < .001). Poor functional outcome at discharge (defined as modified Ranklin Scale 3-6) was more common in the COVID-19 group (150, 79.8% vs 132, 66.7%; P = .004). COVID-19 was independently associated with a lower likelihood of achieving modified thrombolysis in cerebral infarction 3 (odds ratio [OR]: 0.4, 95% CI: 0.2-0.7; P < .001) and unfavorable outcomes (OR: 2.5, 95% CI: 1.4-4.5; P = .002).ConclusionCOVID-19 was an independent predictor of incomplete revascularization and poor outcomes in patients with stroke due to LVO. Patients with COVID-19 with LVO were younger, had fewer cerebrovascular risk factors, and suffered from higher morbidity/mortality rates.

The pediatric population spans a diverse age group,1 from neonates and infants to adult-sized teenagers, each with unique physiological characteristics that must be considered when performing diagnostic cerebral angiography (DCA). Herein we refer to pediatric patients as under the age of 18 years. Neonates will not be discussed further due to the very limited role of DCA in the absence of planned neurointervention, most commonly for vein of Galen malformations and other high-flow arteriovenous fistulas leading to life-threatening heart failure. The number of pediatric neuroangiography procedures performed continues to grow2 and it is evident that the technical aspects of performing pediatric DCA are highly variable among practitioners, including our own Task Force members. This reflects the diversity of angiographers from different specialties and the varying levels of prior pediatric neuroangiography training and experience. In 2019, the Society of Neurointerventional Surgery (SNIS) surveyed its membership regarding their individual fellowship training and current practice as it relates collectively to pediatric neuroangiography, including both diagnostic and interventional procedures. Unpublished results indicate that pediatric neuroangiography training and current experience is limited across the nation (figure 1). Most respondents (94%) performed pediatric DCA during fellowship, though this experience was mostly limited and low volume. In children under 4 years of age, that experience was further reduced (40%: 0–10 cases; 45%: 11–49 cases). Despite this limited exposure, 76% of respondents reported currently treating pediatric patients, though in more than half (53%), that volume remains low: 0–10 pediatric cases per year. Practice guidelines for cervicocerebral catheter angiography have been published for adults,3 however, no similar recommendations exist for children. Given this information, Pediatric Neurointerventional Task Force Committee members of the SNIS sought to provide a framework with which safe pediatric DCA can be performed, detailing specific procedural considerations as well as peri-procedural evaluation and …

OBJECTIVE The development of new endovascular technologies and techniques for mechanical thrombectomy in stroke has greatly relied on benchtop simulators. This paper presents an affordable, versatile, and realistic benchtop simulation model for stroke. METHODS A test bed for embolic occlusion of cerebrovascular arteries and mechanical thrombectomy was developed with 3D-printed and commercially available cerebrovascular phantoms, a customized hydraulic system to generate physiological flow rate and pressure, and 2 types of embolus analogs (elastic and fragment-prone) capable of causing embolic occlusions under physiological flow. RESULTS The test bed was highly versatile and allowed realistic, radiation-free mechanical thrombectomy for stroke due to large-vessel occlusion with rapid exchange of geometries and phantom types. Of the transparent cerebrovascular phantoms tested, the 3D-printed phantom was the easiest to manufacture, the glass model offered the best visibility of the interaction between embolus and thrombectomy device, and the flexible model most accurately mimicked the endovascular system during device navigation. None of the phantoms modeled branches smaller than 1 mm or perforating arteries, and none underwent realistic deformation or luminal collapse from device manipulation or vacuum. The hydraulic system created physiological flow rate and pressure leading to iatrogenic embolization during thrombectomy in all phantoms. Embolus analogs with known fabrication technique, structure, and tensile strength were introduced and consistently occluded the middle cerebral artery bifurcation under physiological flow, and their interaction with the device was accurately visualized. CONCLUSIONS The test bed presented in this study is a low-cost, comprehensive, realistic, and versatile platform that enabled high-quality analysis of embolus–device interaction in multiple cerebrovascular phantoms and embolus analogs.

OBJECTIVE Studies on surgical site infection (SSI) in adult neurosurgery have presented all subtypes of SSIs as the general 'SSI'. Given that SSIs constitute a broad range of infections, we hypothesized that clinical outcomes and management vary based on SSI subtype. METHODS A retrospective analysis of all neurosurgical SSI from 2012-2019 was conducted at a tertiary care institution. SSI subtypes were categorized as deep and superficial incisional SSI, brain, dural or spinal abscesses, meningitis or ventriculitis, and osteomyelitis. RESULTS 9620 craniotomy, shunt, and fusion procedures were studied. 147 procedures (1.5%) resulted in postoperative SSI. 87 (59.2%) of these were associated with craniotomy, 36 (24.5%) with spinal fusion, and 24 (16.3%) with ventricular shunting. Compared with superficial incisional primary SSI, rates of reoperation to treat SSI were highest for deep incisional primary SSI (91.2% vs 38.9% for superficial, p

BACKGROUND Length of stay beyond medical readiness (LOS-BMR) leads to increased expenses and higher morbidity related to hospital-acquired conditions. OBJECTIVE To determine the proportion of admitted neurosurgical patients who have LOS-BMR and associated risk factors and costs. METHODS We performed a prospective, cohort analysis of all neurosurgical patients admitted to our institution over 5 mo. LOS-BMR was assessed daily by the attending neurosurgeon and neuro-intensivist with a standardized criterion. Univariate and multivariate logistic regressions were performed. RESULTS Of the 884 patients admitted, 229 (25.9%) had a LOS-BMR. The average LOS-BMR was 2.7 ± 3.1 d at an average daily cost of $9 148.28 ± $12 983.10, which resulted in a total cost of $2 076 659.32 over the 5-mo period. Patients with LOS-BMR were significantly more likely to be older and to have hemiplegia, dementia, liver disease, renal disease, and diabetes mellitus. Patients with a LOS-BMR were significantly more likely to be discharged to a subacute rehabilitation/skilled nursing facility (40.2% vs 4.1%) or an acute/inpatient rehabilitation facility (22.7% vs 1.7%, P

Thermal therapies have strong potential for improving outcomes for patients suffering from cardiac arrest, neonatal hypoxic-ischemic encephalopathy, or medically refractory intracranial hypertension. We propose a novel tool to manipulate blood temperature through extravascular thermoelectric heat exchange of blood vessel walls and flowing blood. This tool is a concentrated cooling probe with several thermoelectric units combined to focus cooling at the application site. Using this tool, we aim to achieve desired levels of temperature control and potentially reduce complications associated with traditional intravascular or systemic thermal therapies. Leveraging the feedback control, speed, and reversible operation of thermoelectric cooling modules, the device can adapt to cool or heat as desired. Preclinical testing on rodent models confirmed rapid, significant reduction of intravenous jugular blood temperature when a prototype device was brought in contact with the left carotid artery (change in blood temperature of −4.74 ± 2.9 °C/h and −4.29 ± 1.64 °C/h for 0 °C and −5 °C cooling trials, respectively). Declines in rectal temperature were also noted, but at lesser magnitudes than for jugular blood (0 °C: −3.09 ± 1.29 °C/h; −5 °C: −2.04 ± 1.08 °C/h), indicating proof-of-concept of thermoelectric extravascular blood cooling within a relatively localized region of the body. With further improvements in the technique, there is potential for selective organ cooling via a reduction in the temperature of flowing blood.

BackgroundAlthough intracranial aneurysms (IA) and abdominal aortic aneurysms (AAA) share similar risk factors, little is known about the relationship between them. Previous studies have shown an increased incidence of IA in patients with AAA, though the rate of subarachnoid hemorrhage (SAH) in patients with AAA has not been described.ObjectiveTo use claims data with longitudinal follow-up, to evaluate the incidence of aneurysmal SAH in patients diagnosed with AAA.MethodsWe examined longitudinally linked medical claims data from a large private insurer to determine rates of aneurysmal SAH (aSAH) and secured aSAH (saSAH) in 2004–2014 among patients with previously diagnosed AAA.ResultsWe identified 62 910 patients diagnosed with AAA and compared them 5:1 with age- and sex-matched controls. Both populations were predominantly male (70.9%), with an average age of 70.8 years. Rates of hypertension (69.7% vs 50.6%) and smoking (12.8% vs 4.1%) were higher in the AAA group (pConclusionSAH rate was elevated in patients with AAA, even after adjustment for comorbidities. Among risk factors evaluated, AAA was the strongest predictor for SAH. The relative contributions of common genetic and environmental risk factors to both diseases should be investigated.

Surgical intervention for unruptured intracranial aneurysms (IAs) carries inherent health risks. The analysis of “patient-specific” IA geometric and computational fluid dynamics (CFD) simulated wall shear stress (WSS) data has been investigated to differentiate IAs at high and low risk of rupture to help clinical decision making. Yet, outcomes vary among studies, suggesting that novel analysis could improve rupture characterization. The authors describe a CFD analytic method to assess spatiotemporal characteristics of swirling flow vortices within IAs to improve characterization. CFD simulations were performed for 47 subjects harboring one medium-sized (4–10 mm) middle cerebral artery (MCA) aneurysm with available 3D digital subtraction angiography data. Alongside conventional indices, quantified IA flow vortex spatiotemporal characteristics were applied during statistical characterization. Statistical supervised machine learning using a support vector machine (SVM) method was run with cross-validation (100 iterations) to assess flow vortex-based metrics’ strength toward rupture characterization. Relying solely on vortex indices for statistical characterization underperformed compared with established geometric characteristics (total accuracy of 0.77 vs 0.80) yet showed improvements over wall shear stress models (0.74). However, the application of vortex spatiotemporal characteristics into the combined geometric and wall shear stress parameters augmented model strength for assessing the rupture status of middle cerebral artery aneurysms (0.85). This preliminary study suggests that the spatiotemporal characteristics of flow vortices within MCA aneurysms are of value to improve the differentiation of ruptured aneurysms from unruptured ones.

Given the serious nature of many neurosurgical pathologies, it is common for hospitalized patients to elect comfort care (CC) over aggressive treatment. Few studies have evaluated the incidence and risk factors of CC trends in patients admitted for neurosurgical emergencies. To analyze all neurosurgical patients admitted to a tertiary care academic referral center via the emergency department (ED) to determine incidence and characteristics of those who initiated CC measures during their initial hospital admission. We performed a prospective, cohort analysis of all consecutive adult patients admitted to the neurosurgical service via the ED between October 2018 and May 2019. The primary outcome was the initiation of CC measures during the patient’s hospital admission. CC was defined as cessation of life-sustaining measures and a shift in focus to maintaining the comfort and dignity of the patient. Of the 428 patients admitted during the 7-month period, 29 (6.8%) initiated CC measures within 4.0 ± 4.0 days of admission. Patients who entered CC were significantly more likely to have a medical history of cerebrovascular disease (58.6% vs. 33.3%, p = 0.006), dementia (17.2% vs. 1.5%, p = 0.0004), or cancer with metastatic disease (24.1% vs. 7.0%, p = 0.001). Patients with a presenting pathology associated with cerebrovascular disease were significantly more likely to initiate CC (62.1% vs. 35.3, p = 0.04). Patients who underwent emergent surgery were significantly more likely to enter CC compared with those who had elective surgery (80.0% vs. 42.7%, p = 0.02). Only 10 of the 29 (34.5%) patients who initiated CC underwent a neurosurgical operation (p = 0.002). Twenty of the 29 (69.0%) patients died within 0.8 ± 0.8 days after the initiation of CC measures. CC measures were initiated in 6.8% of patients admitted to the neurosurgical service via the ED, with the majority of patients entering CC before an operation and presenting with a cerebrovascular pathology.

The after-hours effect on postoperative complications has been poorly studied in the neurosurgical literature. A recent retrospective analysis showed that patients with a surgical start time (SST) between 09:01 pm and 07:00 am had a greater risk of complications. This study used a prospective registry to examine the relationship between SST and postoperative complications in a large neurosurgical population.We performed a prospective longitudinal cohort analysis of all consecutive adult patients admitted to our neurosurgery service between October 1, 2018 and May 1, 2019. Complications were prospectively recorded and classified as surgical or medical. Univariate and multivariate logistic regressions were used to analyze these data.Eighty-five surgical complications (6.6%) and 110 medical complications (8.6%) resulted from 1285 operations on 1145 patients. Later SST was predictive of complications in the emergent population (odds ratio [OR], 2.28; 95% confidence interval [CI], 1.01-5.15; P = 0.048) but not in the elective population. Extubation in the neurosurgical intensive care unit (NICU) versus the operating room strongly predicted medical complications (OR, 6.91; 95% CI, 3.33-14.34; P0.0001). Patients with a later SST were significantly more likely to be extubated in the NICU (P0.0001).Patients undergoing emergent operations with a later SST were significantly more likely to have a postoperative complication. Patients who were extubated in the NICU versus the operating room were significantly more likely to have a medical complication. Patients were more likely to be extubated in the NICU if they had a later SST; therefore, SST may indirectly be associated with an increase in medical complications.

OBJECTIVE: Our prior studies have found that intracerebroventricular injection of blood components can cause hydrocephalus and choroid plexus epiplexus cell activation in rats. To minimize the cross-species reaction, the current study examines whether intraventricular injection of acellular components of cerebrospinal fluid (CSF) from subarachnoid hemorrhage patients can cause hydrocephalus and epiplexus macrophage activation in nude mice which lack a T-cell inflammatory response. METHODS: Adult male nude mice received intraventricular injections of acellular CSF from subarachnoid hemorrhage patients or a control patient. All mice had preoperative magnetic resonance imaging as baseline and postoperative scans at 24 hours after CSF injection to determine ventricular volume. Brains were harvested at 24 hours for brain histology, immunohistochemistry and electron microscopy. RESULTS: Intraventricular injection of CSF from two of five subarachnoid hemorrhage patients obtained

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

Aims Over the past two decades, animal intracerebral hemorrhage (ICH) model studies have indicated that iron, released after hemoglobin degradation, is neurotoxic. Iron phantom and animal experiments have shown that magnetic resonance imaging (MRI) relaxivity maps correlate with iron concentration. This study expands this into patients. Methods Eighteen human subjects with ICH underwent MRI at 3, 14, and 30 days. R2* relaxivity maps were used to calculate perihematomal iron concentrations and T2 imaging to determine hematoma and edema volumes. Results Perihematomal iron concentrations were increased at all three time points and decreased with distance from the hematoma. While perihematomal iron concentrations did not vary with hematoma size, the total iron overload (increased iron concentration x volume of affected tissue) did. Total iron overload correlated with edema volume. Conclusions These results demonstrate the feasibility of measuring perihematomal iron in ICH patients which may be important for monitoring treatment strategies and assessing efficacy noninvasively.

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.

There is no consensus for the treatment of a tandem occlusion (TO) in a patient presenting with an acute ischemic stroke. In this review article, we will focus on the controversial treatment strategies for TOs. First, we will discuss treatment options including retrograde, antegrade, and delayed approaches. Second, the role of carotid stent placement versus balloon angioplasty for the extracranial occlusion will be presented. Third, anticoagulation and antiplatelet regimens for the treatment TOs published in the literature will be reviewed. Finally, we will discuss whether there is a role for coil occlusion of the cervical carotid artery or whether staged carotid revascularization days after mechanical thrombectomy of the intracranial occlusion maybe appropriate. The optimal treatment strategy of TO has not been established and further larger trials need to be performed to answer the question.

Objective The HOSPITAL score (HS) and LACE index (LI) are 2 validated methods for quantifying the risk of 30-day unplanned readmission after discharge. However, neither score has been validated in the neurosurgical population. This study evaluated the HS and LI in the neurosurgical population as effective predictors for 30-day unplanned readmission. Methods We performed a prospective, cohort analysis of all consecutive adult patients admitted to the neurosurgical service between October 1, 2018 and May 1, 2019. Patient medical records were used to calculate HS and LI. HS defined groups as low risk (0–4), intermediate (5–6), and high (7–12); LI defined risk as low (1–4), moderate (5–9), and high (10–19). Data analysis used univariate and multivariate logistic regressions. Results The 1242 patients included 626 women (50.4%). The average age was 57.9 years, and most patients (86.5%) underwent surgery during their admission. In multivariate logistic regression, intermediate-risk HS was not predictive of 30-day readmission (odds ratio [OR], 1.04; 95% confidence interval [CI], 0.57–1.88; P = 0.53), whereas high-risk HS did predict readmission (OR, 2.87; 95% CI, 1.49–5.54; P = 0.002). Likewise, moderate-risk LI was not predictive of 30-day unplanned readmission or mortality (OR, 1.59; 95% CI, 0.88–2.85; P = 0.12); however, high-risk LI did predict unplanned readmission or mortality (OR, 2.58; 95% CI, 1.16–5.73; P = 0.02). Both HS and LI showed poor to moderate discrimination (C = 0.62 and 0.60, respectively). Conclusions A high-risk HS and high-risk LI were predictive of 30-day unplanned readmission. Although neither score is ideal for predicting moderate risk for 30-day unplanned readmission in neurosurgical patients, both have some predictiveness that may be clinically valuable.

BACKGROUND Aneurysm recurrence after coiling has been associated with aneurysm growth, (re)hemorrhage, and a greater need for follow-up. The second-generation HydroCoil Embolic System (HES; MicroVention, Inc) consists of a platinum core with integrated hydrogel and was developed to reduce recurrence through enhancing packing density and healing within the aneurysm. OBJECTIVE To compare recurrence between the second-generation HES and bare platinum coil (BPC) in the new-generation Hydrogel Endovascular Aneurysm Treatment Trial (HEAT). METHODS HEAT is a randomized, controlled trial that enrolled subjects with ruptured or unruptured 3- to 14-mm intracranial aneurysms amenable to coiling. The primary endpoint was aneurysm recurrence using the Raymond-Roy scale. Secondary endpoints included minor and major recurrence, packing density, adverse events related to the procedure and/or device, mortality, initial complete occlusion, aneurysm retreatment, hemorrhage from target aneurysm during follow-up, aneurysm occlusion stability, and clinical outcome at final follow-up. RESULTS A total of 600 patients were randomized (HES, n = 297 and BPC, n = 303), including 28% with ruptured aneurysms. Recurrence occurred in 11 (4.4%) subjects in the HES arm and 44 (15.4%) subjects in the BPC arm (P = .002). While the initial occlusion rate was higher with BPC, the packing density and both major and minor recurrence rates were in favor of HES. Secondary endpoints including adverse events, retreatment, hemorrhage, mortality, and clinical outcome did not differ between arms. CONCLUSION Coiling of small-to-medium aneurysms with second-generation HES resulted in less recurrence when compared to BPC, without increased harm. These data further support the use of the second-generation HES for the embolization of intracranial aneurysms. VIDEO ABSTRACT

Introduction: Hyperfibrinolysis is associated with intracerebral hemorrhage (ICH) after the use of tPA for acute ischemic stroke (AIS). Point-of-care Rotational ThromboElastoMetry (ROTEM) testing may rapidly detect hyperfibrinolysis and identify AIS patients at high risk for hemorrhage. Hypothesis: Evidence of fibrinogen depletion on ROTEM will accurately predict bleeding following revascularization therapy for AIS. Methods: We reviewed medical records of AIS patients who underwent revascularization therapy between 2019-2020. All patients underwent ROTEM testing post-procedure to facilitate targeted blood product transfusion should hemorrhage occur. However, transfusion was not performed prophylactically. Repeat imaging with dual-energy CT was performed within 24 hours. A quality control registry of all AIS patients who undergo revascularization is maintained for purposes of Joint Commission certification. All variables, including ROTEM values and occurrence of intra- and extracranial hemorrhage, were entered prospectively. We examined the predictive value of a FIBTEM-A10 Results: A total of 52 patients were included. Median age was 68 years (Interquartile Range, IQR 60-83), and median admission NIHSS was 16 (IQR 10-20). Thirty-four patients (65%) received tPA, 46 (88%) received mechanical thrombectomy, and 28 (54%) received both. Median post-procedure FIBTEM-A10 was 16mm (IQR 14-22); 5 patients had values Conclusions: The use of ROTEM to identify hyperfibrinolysis following AIS revascularization therapy achieved poor sensitivity and high specificity for prediction of any post-procedural hemorrhage, but was inaccurate for the prediction of symptomatic ICH.

OBJECTIVEIt is unknown what proportion of patients who undergo emergent neurosurgical procedures initiate comfort care (CC) measures shortly after the operation. The purpose of the present study was to analyze the proportion and predictive factors of patients who initiated CC measures within the same hospital admission after undergoing emergent neurosurgery.METHODSThis retrospective cohort study included all adult patients who underwent emergent neurosurgical and endovascular procedures at a single center between 2009 and 2014. Primary and secondary outcomes were initiation of CC measures during the initial hospitalization and determination of predictive factors, respectively.RESULTSOf the 1295 operations, comfort care was initiated in 111 (8.6%) during the initial admission. On average, CC was initiated 9.3 ± 10.0 days postoperatively. One-third of the patients switched to CC within 3 days. In multivariate analysis, patients > 70 years of age were significantly more likely to undergo CC than those < 50 years (70–79 years, p = 0.004; > 80 years, p = 0.0001). Two-thirds of CC patients had been admitted with a cerebrovascular pathology (p < 0.001). Admission diagnosis of cerebrovascular pathology was a significant predictor of initiating CC (p < 0.0001). A high Hunt and Hess grade of IV or V in patients with subarachnoid hemorrhage was significantly associated with initiation of CC compared to a low grade (27.1% vs 2.9%, p < 0.001). Surgery starting between 15:01 and 06:59 hours had a 1.70 times greater odds of initiating CC compared to surgery between 07:00 and 15:00.CONCLUSIONSInitiation of CC after emergent neurosurgical and endovascular procedures is relatively common, particularly when an elderly patient presents with a cerebrovascular pathology after typical operating hours.

ObjectivesTo integrate morphological, haemodynamic and mechanical analysis of carotid atheroma driving plaque disruption.Materials and methodsFirst, we analysed the phenotypes of carotid endarterectomy specimens in a photographic dataset A, and matched them with the likelihood of preoperative stroke. Second, laser angioscopy was used to further define the phenotypes in intact specimens (dataset B) and benchmark with histology. Third, representative vascular geometries for each structural phenotype were analysed with Computational Fluid Dynamics (CFD), and the mechanical strength of the complicated atheroma to resist penetrating forces was quantified (n=14).ResultsIn dataset A (n=345), ulceration (fibrous cap disruption) was observed in 82% of all plaques, intraplaque haemorrhage in 68% (93% subjacent to an ulcer) and false luminal formation in 48%. At least one of these ‘rupture’ phenotypes was found in 97% of symptomatic patients (n=69) compared with 61% in asymptomatic patients. In dataset B (n=30), laser angioscopy redemonstrated the structural phenotypes with near-perfect agreement with histology. In CFD, haemodynamic stress showed a large pulse magnitude, highest upstream to the point of maximal stenosis and on ulceration the inflow stream excavates the necrotic core cranially and then recirculates into the true lumen. Based on mechanical testing (n=14), the necrotic core is mechanically weak and penetrated by the blood on fibrous cap disruption.ConclusionsFibrous cap ulceration, plaque haemorrhage and excavation are sequential phenotypes of plaque disruption resulting from the chiselling effect of haemodynamic forces over unmatched mechanical tissue strength. This chain of events may result in thromboembolic events independently of the degree of stenosis.

Background and PurposeGiven the relatively short duration and multiple facets of education, both interventional and diagnostic neuroradiology fellowships must be used efficiently. As hospital systems utilize resources to provide clinical care of patients with COVID-19, the overall number of elective neurointerventional procedures has been limited and the overall volume of diagnostic imaging has decreased. This article will evaluate and discuss the impact of procedural volumes between two academic centers, the impact on overall diagnostic neuroradiology imaging volume, and the rapid migration to online web-based education and research collaboration on both interventional and diagnostic neuroradiology fellowship experiences in the COVID-19 era.Material and methodsA retrospective review was conducted at two academic tertiary care hospitals to evaluate the change in overall elective and emergent neurointerventional case volume during the COVID-19 pandemic spanning from January 2020 - April 2020 and those volumes were compared to pre-COVID-19 case volume during January 2019-April 2019. A single center comparison of annual neurointerventional case numbers during 2019 and 2020 was performed with sub-analyses of case types. Annual diagnostic neuroradiology imaging volume was also evaluated for 2019 and 2020.ResultsBoth tertiary care academic medical centers experienced a statistically significant decrease in the number of elective neurointerventional cases between March - April 2019 and March - April 2020. There was also a statistical different decrease in elective case volume during the fourth quarter of the 2020 academic year (April - June). A statistically significant decrease in case volume was not seen in the setting of thrombectomy for acute ischemic stroke. A statistically significant decrease in aneurysmal subarachnoid hemorrhage (aSAH) case volume was only seen at site #2. Between 2019 and 2020 there was a 32% drop in neuroradiology case volume during the fourth quarter of the 2020 academic year (April - June). Similar sizable decreases in diagnostic neuroradiology case volume were not appreciated in the remaining quarters of 2019 and 2020.ConclusionElective neurointerventional case numbers decreased as a result of the COVID-19 pandemic, particularly impacting the fourth quarter of the 2019-2020 academic year (April - June). Similarly, there was a sizable decrease in diagnostic neuroradiology case volume during this same time period. The decrease in procedural and diagnostic neuroradiology cases raised concerns regarding the educational experience for both diagnostic and neurointerventional radiology fellows. However, as a result of decreased case volume, fellowship education was rapidly augmented with a wide variety of online webinars, lectures, case conferences, and research collaborations.DisclosuresZ. Wilseck: None. S. Bamezai: None. N. Novakovic: None. A. Copelan: None. J. Wilseck: None. A. Srinivasan: None. A. Pandey: None. G. Thompson: None. J. Gemmete: None. N. Chaudhary: None.

Background The coronavirus disease 2019 (COVID-19) pandemic is an ongoing public health emergency. While most cases end in asymptomatic or minor illness, there is growing evidence that some COVID-19 infections result in nonconventional dire consequences. We sought to describe the characteristics of patients with intracranial hemorrhage who were infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Also, with the existing literature, we raise the idea of a possible association between SARS-CoV-2 infection and intracranial hemorrhage and propose possible pathophysiological mechanisms connecting the two. Methods We retrospectively collected and analyzed intracranial hemorrhage cases who were also positive for SARS-CoV-2 from 4 tertiary-care cerebrovascular centers. Results We identified a total of 19 patients consisting of 11 males (58%) and 8 females (42%). Mean age was 52.2, with 95% younger than 75 years of age. With respect to COVID-19 illness, 50% had mild-to-moderate disease, 21% had severe disease, and 20% had critical disease requiring intubation. Of the 19 cases, 12 patients had intraparenchymal hemorrhage (63%), 6 had subarachnoid hemorrhage (32%), and 1 patient had a subdural hematoma (5%). A total of 43% had an intracerebral hemorrhage score of 0–2 and 57% a score of 3–6. Modified Rankin Scale cores at discharge were 0–2 in 23% and 3–6 in 77%. The mortality rate was 59%. Conclusions Our series sheds light on a distinct pattern of intracerebral hemorrhage in COVID-19–positive cases compared with typical non–COVID-19 cases, namely the severity of hemorrhage, high mortality rate, and the young age of patients. Further research is warranted to delineate a potential association between SARS-CoV-2 infection and intracranial hemorrhage.

White matter (WM) injury and survival after intracerebral hemorrhage (ICH) has received insufficient attention. WM disruption surrounding the hematoma has been documented in animal models with histology, but rarely in human ICH with noninvasive means, like magnetic resonance imaging (MRI). A few human MRI studies have investigated changes in long WM tracts after ICH remote from the hematoma, like the corticospinal tract, but have not attempted to obtain an unbiased quantification of WM changes within and around the hematoma over time. This study attempts such quantification from 3 to 30 days post ictus. Thirteen patients with mild to moderate ICH underwent diffusion tensor imaging (DTI) MRI at 3, 14, and 30 days. Fractional anisotropy (FA) maps were used to calculate the volume of tissue with FA &gt, 0.5, both within the hematoma (lesion) and in the perilesional tissue. At day 3, the percentages of both lesional and perilesional tissue with an FA &gt, 0.5 were significantly less than contralateral, unaffected, anatomically identical tissue. This perilesional contralateral difference persisted at day 14, but there was no significant difference at day 30. The loss of perilesional tissue with FA &gt, 0.5 increased with increasing hematoma size at day 3 and day 14. All patients had some tissue within the lesion with FA &gt, 0.5 at all time points. This did not decrease with duration after ictus, suggesting the persistence of white matter within the hematoma/lesion. These results outline an approach to quantify WM injury, both within and surrounding the hematoma, after mild to moderate ICH using DTI MRI. This may be important for monitoring treatment strategies, such as hematoma evacuation, and assessing efficacy noninvasively.

OBJECTIVEGastrostomy tube placement can temporarily seed the peritoneal cavity with bacteria and thus theoretically increases the risk of shunt infection when the two procedures are performed contemporaneously. The authors hypothesized that gastrostomy tube placement would not increase the risk of ventriculoperitoneal shunt infection. The object of this study was to test this hypothesis by utilizing a large patient cohort combined from multiple institutions.METHODSA retrospective study of all adult patients admitted to five institutions with a diagnosis of aneurysmal subarachnoid hemorrhage between January 2005 and January 2015 was performed. The primary outcome of interest was ventriculoperitoneal shunt infection. Variables, including gastrostomy tube placement, were tested for their association with this outcome. Standard statistical methods were utilized.RESULTSThe overall cohort consisted of 432 patients, 47% of whom had undergone placement of a gastrostomy tube. The overall shunt infection rate was 9%. The only variable that predicted shunt infection was gastrostomy tube placement (p = 0.03, OR 2.09, 95% CI 1.07–4.08), which remained significant in the multivariate analysis (p = 0.04, OR 2.03, 95% CI 1.04–3.97). The greatest proportion of shunts that became infected had been placed more than 2 weeks (25%) and 1–2 weeks (18%) prior to gastrostomy tube placement, but the temporal relationship between shunt and gastrostomy was not a significant predictor of shunt infection.CONCLUSIONSGastrostomy tube placement significantly increases the risk of ventriculoperitoneal shunt infection.

Aneurysmal subarachnoid hemorrhage (aSAH) continues to be associated with significant morbidity and mortality despite advances in care and aneurysm treatment strategies. Cerebral vasospasm continues to be a major source of clinical worsening in patients. We intended to review the clinical and experimental aspects of aSAH and identify strategies that are being evaluated for the treatment of vasospasm. A literature review on aSAH and cerebral vasospasm was performed. Available treatments for aSAH continue to expand as research continues to identify new therapeutic targets. Oral nimodipine is the primary medication used in practice given its neuroprotective properties. Transluminal balloon angioplasty is widely utilized in patients with symptomatic vasospasm and ischemia. Prophylactic “triple‐H” therapy, clazosentan, and intraarterial papaverine have fallen out of practice. Trials have not shown strong evidence supporting magnesium or statins. Other calcium channel blockers, milrinone, tirilazad, fasudil, cilostazol, albumin, eicosapentaenoic acid, erythropoietin, corticosteroids, minocycline, deferoxamine, intrathecal thrombolytics, need to be further investigated. Many of the current experimental drugs may have significant roles in the treatment algorithm, and further clinical trials are needed. There is growing evidence supporting that early brain injury in aSAH may lead to significant morbidity and mortality, and this needs to be explored further.