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Irrigation during intraventricular endoscopic surgery is critical for visualization, with normal intracranial pressure maintained by balancing fluid ingress and egress. Although irrigation is typically achieved through manual manipulation of inexact stopcocks, the authors have developed a rate-controlled, foot pedal–activated system for precise intraventricular irrigation by using a standard irrigating bipolar electrocautery machine.This study is a retrospective review of patients who underwent endoscopic intraventricular surgery between January 1, 2018, and September 25, 2019, in which this irrigation system was used. Important components of this system include a bipolar module irrigation regulator that is set to a desired rate, a secure connection of the bipolar irrigation tubing to the endoscope, and one or more open egress ports on the endoscope for passive fluid drainage. Nineteen consecutive patients were identified on review (average age ± SD, 4.3 ± 4.1 years). Procedures performed included third ventriculostomies (n = 10); arachnoid/choroid cyst fenestrations/resections (n = 3); biopsy/tumor resection (n = 1); and combined procedures (n = 5). Foot pedal–controlled irrigation provided visualization of all intraventricular structures. A single operator was able to control the endoscope, endoscopic instruments, and irrigation, with assistance as indicated for more complex maneuvers. There were no perioperative complications. Because this setup is easily constructed from a standard irrigating bipolar machine, delivers precise irrigation flow rates, and facilitates a single-surgeon bimanual technique, these data support the utility of foot-controlled irrigation for endoscopic intraventricular surgery.

Background Crossing a nascently deployed carotid artery stent (CAS) is required to perform angioplasty and filter recapture. If the traversing balloon or filter recapture catheters are eccentric or tangentially angled to the vertical axis of the CAS, they can ensnare on the ledge of the proximal CAS step-off, potentially causing life-threatening complications secondary to deformation, displacement, or mechanical occlusion of the stent. We report a novel “balloon bridge” technique that facilitates safe entry and passage across the CAS with both a balloon catheter and a large-bore guide catheter (LBGC). Methods We used the balloon bridge technique for 2 patients with >90% carotid artery stenosis and steep carotid artery angles of origin who underwent routine CAS, balloon angioplasty, and distal embolic protection. During filter recapture, the balloon was inflated across the junction of the distal LBGC tip and proximal CAS, centering the LBGC within the vessel lumen and CAS. During balloon deflation, the LBGC was sequentially advanced, successfully navigating the LBGC across the proximal stent construct without resistance or complication. Results The balloon bridge technique was completed without complications. We believe that the mechanism of action is secondary to balloon-facilitated LBGC alignment with the true axis of the stent. Conclusions Traversing a CAS with an LBGC or balloon catheter can be tedious and fraught with the potential of neurologic peril should mechanical deformation and occlusion occur. The balloon bridge technique is safe and highly effective for navigating a catheter that is eccentric or tangentially angled to the long axis of a CAS.

Cerebral venous sinus thrombosis (CVST) is a rare cause of stroke, but if left untreated, it can result in significant morbidity or mortality. Complications of CVST include cerebral infarction, cerebral hemorrhage, focal neurologic deficit, hydrocephalus, seizure, coma, and death. Therefore, prompt diagnosis and initiation of treatment is critical. Noninvasive imaging modalities can often readily identify CVST. Systemic anticoagulation is the mainstay of CVST treatment, even in cases associated with cerebral hemorrhage. For patients who are refractory to medical management, endovascular therapy may be used as an adjunctive treatment. After the acute phase, evaluation for underlying hypercoaguable disorders is necessary to risk stratify patients and determine their duration of anticoagulation. This chapter presents a case of a patient with symptomatic CVST. Relevant diagnostic and treatment strategies are discussed.

Background Intraoperative MRI has been shown to improve gross-total resection of high-grade glioma. However, to the knowledge of the authors, the cost-effectiveness of intraoperative MRI has not been established. Purpose To construct a clinical decision analysis model for assessing intraoperative MRI in the treatment of high-grade glioma. Materials and Methods An integrated five-state microsimulation model was constructed to follow patients with high-grade glioma. One-hundred-thousand patients treated with intraoperative MRI were compared with 100 000 patients who were treated without intraoperative MRI from initial resection and debulking until death (median age at initial resection, 55 years). After the operation and treatment of complications, patients existed in one of three health states: progression-free survival (PFS), progressive disease, or dead. Patients with recurrence were offered up to two repeated resections. PFS, valuation of health states (utility values), probabilities, and costs were obtained from randomized controlled trials whenever possible. Otherwise, national databases, registries, and nonrandomized trials were used. Uncertainty in model inputs was assessed by using deterministic and probabilistic sensitivity analyses. A health care perspective was used for this analysis. A willingness-to-pay threshold of $100 000 per quality-adjusted life year (QALY) gained was used to determine cost efficacy. Results Intraoperative MRI yielded an incremental benefit of 0.18 QALYs (1.34 QALYs with intraoperative MRI vs 1.16 QALYs without) at an incremental cost of $13 447 ($176 460 with intraoperative MRI vs $163 013 without) in microsimulation modeling, resulting in an incremental cost-effectiveness ratio of $76 442 per QALY. Because of parameter distributions, probabilistic sensitivity analysis demonstrated that intraoperative MRI had a 99.5% chance of cost-effectiveness at a willingness-to-pay threshold of $100 000 per QALY. Conclusion Intraoperative MRI is likely to be a cost-effective modality in the treatment of high-grade glioma. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Bettmann in this issue.

OBJECT: High-grade gliomas (HGGs) have poor survival and high treatment costs. Intraoperative MRI (ioMRI) improves gross-total resection (GTR) rates and prolongs progression-free survival (PFS) in HGGs, but questions regarding its cost-effectiveness persist. To date, no clinical decision analysis models assessing ioMRI in the treatment of HGG exist. METHODS: An integrated 5-state microsimulation model was constructed to follow patients with HGG. Patients treated with ioMRI were compared to those without ioMRI from initial resection/debulking until death. Following surgery and treatment of complications, patients existed in one of 3 health states: PFS, progressive disease, or dead. Patients with recurrence were offered up to two repeat resections. PFS, health utility values, probabilities, and costs were obtained from randomized-controlled trials whenever possible. Otherwise, national databases, registries, and non-randomized trials were used. Uncertainty in model inputs was assessed using deterministic and probabilistic sensitivity analyses. A healthcare perspective was taken for this analysis. A willingness to pay (WTP) threshold of $100,000/QALY gained was used to determine cost-efficacy. RESULTS: IoMRI yielded an incremental benefit of 0.18 QALYs (1.16 QALYs without ioMRI vs. 1.34 with) at an incremental cost of $13,447 ($157,000 without vs. $170,447 with) in microsimulation modeling, resulting in an incremental cost-effectiveness ratio (ICER) of $76,442 per QALY. Given our parameter distributions, probabilistic sensitivity analysis demonstrated that ioMRI had a 99.5% chance of cost-effectiveness at a WTP threshold of $100,000/QALY. CONCLUSION: Intra-operative MRI is likely a cost-effective modality in the treatment of HGGs.

Normal and pathologic cells secrete extracellular vesicles (EV), which are defined as 30-2,000 nm spherical organelles. It has been found that EV mediate various biological functions including cellular remodeling and export of biomolecules, extracellular communication, immune stimulation and suppression, and modulation of the cellular microenvironment. EV secreted by human glioma cells contain a wealth of tumor-specific proteins and nucleic acids that can be isolated from patients with these neoplasms. Thus, EV contribute to the development of biomarkers, and additionally have certain therapeutic potential for possible use in neuro-oncology and neurosurgery.

Introduction: Delays in door to groin puncture time (DGPT) for patients with ischemic stroke caused by acute large vessel occlusions (LVO) are associated with worse clinical outcomes. We present the results of a quality improvement protocol for endovascular stroke treatment at the University of California, San Diego (UCSD) that aimed to minimize DGPT. Materials and Methods: Our stroke team implemented a series of quality improvement measures to decrease DGPT, with a target of 90 minutes or less. Sixty-three patients treated at our center were retrospectively divided into three groups based on the date of their intervention as a proxy for the implementation of process improvement protocols: 23 patients treated from July to December 2015, 24 patients treated from January to July 2016, and 16 patients treated from July 2016 to December 2016. Multivariate log-linear and logistic regression analyses were used to assess the predictors of prolonged DGPT and compliance with target DGPT (

Background: Quality improvement protocols (QI) aim to reduce in-hospital delays that result in prolonged door-to-groin-puncture time (DGPT) for the endovascular treatment of ischemic stroke. At our institution, we implemented a comprehensive QI protocol to reduce DGPT from June 2015 to December 2016. Here we discuss the QI protocol on DGPT across diverse modes of arrival to our interventional suite. Methods: 61 patients underwent mechanical thrombectomy for ischemic stroke during our QI period. Independent samples t-tests were used to investigate differences in DGPT early in the QI protocol (July 2015 to February 2016, n=30) versus late in the QI protocol (March 2016 to December 2016, n=31) for patients that presented via emergency medical services (EMS), inpatient, and hospital transfers. Results: Each mode of arrival demonstrated reductions in DGPT (Figure 1). The greatest reduction in DGPT was for the 23 patients within the emergency medical services (EMS) group with a mean reduction of 39 minutes which approached, but didn’t achieve, statistical significance (138 vs. 99; p=0.06). Discussion: QI interventions impact DGPT across different patient arrival methods. QI protocols accounting for patient presentation allow tailored approaches to institutional measures to reduce DGPT.

Normal and pathologic cells secrete extracellular vesicles (EV), which are defined as 30-2,000 nm spherical organelles. It has been found that EV mediate various biological functions including cellular remodeling and export of biomolecules, extracellular communication, immune stimulation and suppression, and modulation of the cellular microenvironment. EV secreted by human glioma cells contain a wealth of tumor-specific proteins and nucleic acids that can be isolated from patients with these neoplasms. Thus, EV contribute to the development of biomarkers, and additionally have certain therapeutic potential for possible use in neuro-oncology and neurosurgery.

Trigeminal neuralgia is a rare syndrome classically described as brief paroxysms of severe, lancinating facial pain along a unilateral trigeminal nerve distribution. Numerous clinical presentations of trigeminal neuralgia exist, with various distinct etiologies. Several classification schemes have been designed for clinical and research purposes. However, varying terminology and inconsistent utilization of these systems can lead to diagnostic confusion and ungeneralizable research findings. Similarly, multiple pain scales have been used for trigeminal neuralgia with differing degrees of granularity, validity, and reliability. This chapter provides an overview of the commonly used classification systems and pain scales in the context of their evolution and utilization. Furthermore, the authors provide recommendations for application of these systems to clinical and research practice.

Arteriovenious malformations (AVMs) are associated with significant morbidity and mortality, and have a rupture risk of ~3% per year. Treatment of AVMs must be tailored specifically to the lesion, with surgical resection being the gold standard for small, accessible lesions. Pre-operative embolization of AVMs can reduce nidal blood flow and remove high-risk AVM features such as intranidal or venous aneurysms, thereby simplifying a challenging neurosurgical procedure. Herein, we describe our approach for the staged endovascular embolization and open resection of AVMs, and highlight the advantages of having a comprehensively trained neurovascular surgeon leading a multi-disciplinary clinical team. This includes planning the craniotomy and resection to immediately follow the final embolization stage, thereby using a single session of anesthesia for aggressive embolization, and rapid resection. Finally, we provide a representative case of a 22-year-old female with an unruptured right frontal AVM diagnosed during a seizure workup, who was successfully treated via staged embolizations followed by open surgical resection.

Objective Early case series suggest that the recently introduced Low-profile Visualized Intraluminal Support Junior (LVIS Jr.) device (MicroVention-Terumo, Inc., Tustin, CA) may be used to treat wide-necked aneurysms that would otherwise require treatment with intrasaccular devices or open surgery. We report our single-center experience utilizing LVIS Jr. to treat intracranial aneurysms involving 1.8-2.5 mm parent arteries. Methods We retrospectively reviewed records of patients treated with the LVIS Jr. device for intracranial aneurysms at a single center. A total of 21 aneurysms were treated in 18 patients. Aneurysms were 2-25 mm in diameter; one was ruptured, while three had recurred after previous rupture and treatment. Lesions were distributed across the anterior (n=12) and posterior (n=9) circulations. Three were fusiform morphology. Results Stent deployment was successful in 100% of cases with no immediate complications. Seventeen aneurysms were treated with stent-assisted coil embolization resulting in immediate complete occlusion in 94% of cases. Two fusiform aneurysms arising from the posterior circulation were further treated with elective clip ligation after delayed expansion and recurrence; no lesions required further endovascular treatment. Four aneurysms were treated by flow diversion with stand-alone LVIS Jr. stent, and complete occlusion was achieved in three cases. Small foci of delayed ischemic injury were noted in two patients in the setting of antiplatelet medication noncompliance. No in-stent stenosis, migration, hemorrhage, or permanent deficits were observed. Good functional outcome based on the modified Rankin Scale score (mRS ≤ 2) was achieved in 100% of cases. Conclusion Our midterm results suggest that the LVIS Jr. stent may be used for a variety of intracranial aneurysms involving small parent arteries (1.8-2.5 mm) with complete angiographic occlusion, parent vessel preservation, and functional clinical outcomes. This off-label expansion would increase the number of aneurysms amenable to endovascular treatment. Future studies may build upon our experiences with flow diversion and treatment of complex or multiple lesions.

Introduction: Delays in door to groin puncture time (DGPT) for patients with ischemic stroke caused by acute large vessel occlusion (LVO) correlate with worse clinical outcomes. Stroke centers aim to minimize DGPT to facilitate prompt intervention and limit ischemic brain injury. In this study, we present the results of a comprehensive quality assessment at the University of California, San Diego (UCSD). From 2015 to 2016, institutional implementation of a quality improvement protocol significantly reduced DGPT. Materials and Methods: Beginning July 2015, the UCSD interdisciplinary stroke team implemented a series of quality improvement measures to decrease DGPT, with a target of 90 minutes or less. After each case, areas of inefficiency were identified and changes were implemented based on direct feedback from neurointerventional physicians and ancillary staff. Changes included: 1) creation of a pager group notification system to activate the entire neurointerventional team simultaneously, 2) consistently involving anesthesia with each neurointervention, 3) streamlining communication between the vascular neurology and neurointervention teams, and 4) structuring parallel workflows to enhance mobilization speed. R statistical software was utilized to compare DGPT before and after implementation of these process improvements. Patients were divided into three groups based on the date of their intervention as follows: 23 patients treated from July-December 2015, 24 patients treated from January-July 2016, and 14 patients treated from July 2016-December 2016. A multivariable univariate binary logistic regression model was constructed to capture predictors of compliance with our target DGPT ( Results: 61 patients underwent mechanical thrombectomy for treatment of acute LVO from July 2015 to December 2016. In our analysis, date of intervention—as a proxy for implementation of process improvement protocols—and mode of admission were predictive of compliance with target DGPT. Patients who were treated from July 2016 to December 2016—after full implementation of process improvements— were 9.5 times more likely to meet or exceed the target DGPT compared to patients treated July 2015 to December 2015 (p=0.01). Additionally, arrival via transfer from an outside hospital was determined to be an independent predictor of meeting DGPT goals. (p=0.02). Conclusion: UCSD’s quality improvement process effected dramatic, statistically significant improvement in DGPT. This analysis demonstrates the utility of a formal quality improvement system at a large, academic comprehensive stroke center.

Extracellular vesicles (EVs) are cell-secreted vesicles that range from 30–2000 nm in size. These vesicles are secreted by both normal and neoplastic cells. Physiologically, EVs serve multiple critical biologic functions, including cellular remodeling, intracellular communication, modulation of the tumor microenvironment and regulation of immune function. Because EVs contain genetic and proteomic contents that reflect the cell of origin, it is possible to detect tumor-specific material in EVs secreted by cancer cells. Importantly, EVs secreted by cancer cells transgress anatomic compartments and can be detected in the blood, cerebrospinal fluid, and other biofluids of cancer patients. In this context, there is a growing interest in analyzing EVs from the biofluid of cancer patients as a means of disease diagnosis and therapeutic monitoring. In this article, we review the development of EVs as a diagnostic platform for the most common form of brain cancer, glioblastoma, discuss potential clinical translational opportunities and identify the central challenges associated with future clinical applications.

BACKGROUND: Small, blister-like aneurysms (BLAs), by virtue of their unique morphology, are difficult to treat with conventional modalities. The use of oversized self-expanding stents as monotherapy for BLAs is a relatively new and promising concept that warrants further investigation. OBJECTIVE: To clarify the role of oversized self-expanding stents as monotherapy for BLAs. METHODS: Five consecutive patients were treated for BLAs with oversized self-expanding stents alone by the senior author (K.R.B.). We report on their clinical and radiographic outcomes. RESULTS: All 5 patients in our series were discharged in good clinical condition. Complete aneurysm occlusion was observed in all patients at the time of most recent radiographic follow-up. Mean follow-up time was 13.6 months (range, 1 month to 4.5 years). CONCLUSION: The use of oversized self-expanding stents to redirect flow away from aneurysms is an effective option for patients with BLAs. This approach represents an alternative to the use of flow diverters.

Background We describe the histopathology of an unruptured giant calcified left middle cerebral artery (MCA) fusiform aneurysm initially treated with endovascular flow diversion. The flow diversion construct underwent postoperative in-stent thrombosis, necessitating surgical resection of the aneurysm to eliminate mass effect. Methods A 75-year-old woman with a known left MCA aneurysm presented to the emergency department with moderate right hemibody weakness. Owing to the clinical and radiographic progression of the aneurysm, the patient was offered treatment. She was initially offered open surgical management of the lesion but declined it, indicating that she would consider only endovascular treatment. The patient underwent endovascular reconstruction of the aneurysmal segment with an overlapping pipeline construct. Postoperatively, the patient experienced in-stent thrombosis of the pipeline construct. The thrombosed aneurysm exerted a progressive local mass effect, necessitating en bloc surgical resection of the aneurysm and stent construct. The aneurysm was submitted for pathological analysis, which demonstrated chronologically older thrombus outside the flow diversion construct. Results Postsurgical imaging demonstrated a left MCA territory stroke. The patient gradually gained strength in her right hemibody. The histopathological analysis indicated that the degrees of platelet activation and clot formation in this case were dependent on the aggregate surface area of the thrombus and surface area of the pipeline device used in the reconstruction. Conclusions This technical report with histopathological analysis provides useful insight into the mechanism of aneurysmal thrombosis after flow diversion. It also raises new questions regarding the roles of thrombus formation, platelet aggregation, and stent construct surface area in the maintenance of vessel patency.

This study establishes performance metrics for angiography and neuroendovascular surgery procedures based on longitudinal improvement in individual trainees with differing levels of training and experience. Over the course of 30 days, five trainees performed 10 diagnostic angiograms, coiled 10 carotid terminus aneurysms in the setting of subarachnoid hemorrhage, and performed 10 left middle cerebral artery embolectomies on a Simbionix Angio Mentor™ simulator. All procedures were nonconsecutive. Total procedure time, fluoroscopy time, contrast dose, heart rate, blood pressures, medications administered, packing densities, the number of coils used, and the number of stent-retriever passes were recorded. Image quality was rated, and the absolute value of technically unsafe events was recorded. The trainees’ device selection, macrovascular access, microvascular access, clinical management, and the overall performance of the trainee was rated during each procedure based on a traditional Likert scale score of 1=fail, 2=poor, 3=satisfactory, 4=good, and 5=excellent. These ordinal values correspond with published assessment scales on surgical technique. After performing five diagnostic angiograms and five embolectomies, all participants demonstrated marked decreases in procedure time, fluoroscopy doses, contrast doses, and adverse technical events; marked improvements in image quality, device selection, access scores, and overall technical performance were additionally observed (p < 0.05). Similarly, trainees demonstrated marked improvement in technical performance and clinical management after five coiling procedures (p < 0.05). However, trainees with less prior experience deploying coils continued to experience intra-procedural ruptures up to the eighth embolization procedure; this observation likely corresponded with less tactile procedural experience to an exertion of greater force than appropriate for coil placement. Trainees across all levels of training and prior experience demonstrated a significant performance improvement after completion of our simulator curriculum consisting of five diagnostic angiograms, five embolectomy cases, and 10 aneurysm coil embolizations.

Although there have been reports of carotid artery pseudoaneurysm formation after adenoidectomy and/or tonsillectomy secondary to iatrogenic injury, there are no case reports of successful endovascular reconstruction of the injured artery in the pediatric population. In most pediatric cases, the internal carotid artery (ICA) is sacrificed. The authors report on a 6-year-old girl who presented with odynophagia, left-sided Horner's syndrome, hematemesis, and severe anemia 6 months after a tonsillectomy. On examination she was found to have a pulsatile mass along the left posterior lateral oropharynx, and imaging demonstrated a dissection of the extracranial left ICA and an associated pseudoaneurysm. The lesion was managed endovascularly with stent-assisted coil embolization and ICA reconstruction. The child had a somewhat complicated postoperative course, requiring additional coil embolization for treatment of a minor recurrence of the pseudoaneurysm at 5 months after the initial treatment and then presenting with extrusion of a portion of the coil mass into the oropharyngeal cavity a year later. She underwent surgical removal of the extruded coils and repair of the defect and has since been free of symptoms or signs of recurrence. The authors conclude that this strategy definitively protected the patient against an oral exsanguination or aspiration event secondary to aneurysm rupture and reduced her risk of stroke by preserving vessel patency and caliber. Moreover, they note that covered stent reconstruction surrenders endovascular access and cannot immediately provide these benefits.

Neuroprotective strategies for the medical management of traumatic brain injury (TBI) have been elusive. While laboratory studies provide a conceptual framework for the potential efficacy of corticosteroids in this context, clinical trials testing this hypothesis have yielded no convincing evidence of clinical benefit. Here, we review the five key randomized control trials (RCTs) that have examined this issue. Based on the proposed primary endpoints of these RCTs, the five RCTs consistently showed that corticosteroids do not confer significant benefit in the TBI population.

Neurofibromatosis type 1 (NF1) is associated with systemic vascular disease, and it can also affect intracranial vasculature in a small percentage of patients. Very rarely, NF1 may co-present with hypoplasia of the internal carotid artery (ICA). Prior reports have documented NF1 with bilateral optic gliomas and a unilateral hypoplastic internal carotid artery; however, we report a case with the aforementioned findings in addition to a right-sided lentiform mass. This case report further suggests a common congenital pathway related to neurofibromin loss of function resulting in both nerve sheath tumors and cerebrovascular anomalies.

Metastatic tumors are the most common brain tumors in adults, and their incidence is increasing. An accurate understanding of the epidemiology of metastatic brain tumors is useful for health care professionals to allocate appropriate clinical, diagnostic, therapeutic, and research resources. Reported incidences in the literature are derived from epidemiologic population-based studies; clinical studies from surgical, radiological, and autopsy series; and reviews of hospital and clinical medical records. Despite these various sources of information, an accurate incidence of metastatic brain tumors is difficult, and current figures are estimates at best. Here, we review the available data regarding the epidemiology of metastatic brain tumors.

OBJECTIVE In vivo and in vitro studies have demonstrated histological evidence of iatrogenic endothelial injury after stent retriever thrombectomy. However, noncontrast vessel wall (VW)–MRI is insufficient to demonstrate vessel injury. Authors of this study prospectively evaluated iatrogenic endothelial damage after stent retriever thrombectomy in humans by utilizing high-resolution contrast-enhanced VW-MRI. Characterization of VW-MRI changes in vessels subject to mechanical injury from thrombectomy may allow better understanding of the biological effects of this intervention. METHODS The authors prospectively recruited 11 patients for this study. The treatment group included 6 postthrombectomy patients and the control group included 5 subjects undergoing MRI for nonvascular indications. All subjects were evaluated on a Signa HD× 3.0-T MRI scanner with an 8-channel head coil. Both pre- and postcontrast T1-weighted Cube VW images as well as MR angiograms were acquired. Sequences obtained for evaluation of the brain parenchyma included diffusion-weighted, gradient echo, and T2-FLAIR imaging. Two independent neuroradiologists, who were blinded to the treatment status of each patient, determined the presence of VW enhancement. Patient age, National Institutes of Health Stroke Scale score on presentation, location of occlusion, stroke etiology, type of device used, number of device deployments, Thrombolysis in Cerebral Infarction (TICI) reperfusion score, stroke volume, and 90-day modified Rankin Scale score were also noted. RESULTS Postcontrast T1-weighted VW enhancement was detected in the M2 segment in 100% of the thrombectomy patients, in the M1 segment in 83%, and in the internal carotid artery in 50%. One patient also demonstrated A1 segment enhancement, which was attributable to thrombectomy treatment of that vessel segment during the same procedure. None of the control patients demonstrated VW enhancement of their intracranial vasculature on T1-weighted images. CONCLUSIONS The study findings suggest that VW injury incurred during stent retriever thrombectomy can be reliably detected utilizing contrast-enhanced 3-T VW-MRI. The results further demonstrate that endothelial injury is associated with oversizing of stent retrievers relative to the treated vessel. Further studies are needed to evaluate the clinical significance of endothelial injury and to characterize the differential effects of various devices.

OBJECTIVE Carotid artery stenting (CAS) has antihypertensive effects, but the durability and degree of this response remain variable. The authors propose that this clinical variability is a function of the presence or absence of a complete circle of Willis (COW). Incomplete COWs perfuse through a higher-resistance pial collateral pathway, and therefore patients may require a higher mean arterial pressure (MAP). Carotid artery revascularization in these patients would reduce the end-organ collateral demand that has been hypothesized to drive the MAP response. METHODS Using a retrospective, nonrandomized within-subject case-control design, the authors compared the postoperative effects of CAS in patients with and without a complete COW by using changes in MAP and antihypertensive medication as end points. They recorded MAP and antihypertensive medications 3 months prior to surgery, preoperatively, immediately postoperatively, and at the 3-month follow-up. RESULTS Data were collected from 64 consecutive patients undergoing CAS. Patients without a complete COW (25%) were more likely to demonstrate a decrease in BP response to stenting (i.e., a drop in MAP of 10 mm Hg and/or a reduction or cessation of BP medications at 3 months postoperatively). Of the patients in the incomplete COW cohort, 75% had this outcome, whereas of those in the complete COW cohort, only 41% had it (p < 0.041). These findings remained statistically significant in a logistic regression analysis for possible confounders (p < 0.024). A receiver operating curve analysis of preoperative data indicated that a MAP > 96.3 mm Hg was 55.5% sensitive and 57.4% specific for predicting a complete COW and that patients with a MAP > 96.3 mm Hg were more likely to demonstrate a good MAP decrease following CAS (p < 0.0092). CONCLUSIONS CAS is associated with a significant decrease in MAP and/or a reduction/cessation in BP medications in patients in whom a complete COW is absent.

Differentiating between low-grade gliomas (LGGs) of astrocytic and oligodendroglial origin remains a major challenge in neurooncology. Here the authors analyzed The Cancer Genome Atlas (TCGA) profiles of LGGs with the goal of identifying distinct molecular characteristics that would afford accurate and reliable discrimination of astrocytic and oligodendroglial tumors. They found that 1) oligodendrogliomas are more likely to exhibit the glioma-CpG island methylator phenotype (G-CIMP), relative to low-grade astrocytomas; 2) relative to oligodendrogliomas, low-grade astrocytomas exhibit a higher expression of genes related to mitosis, replication, and inflammation; and 3) low-grade astrocytic tumors harbor microRNA profiles similar to those previously described for glioblastoma tumors. Orthogonal intersection of these molecular characteristics with existing molecular markers, such as IDH1 mutation, TP53 mutation, and 1p19q status, should facilitate accurate and reliable pathological diagnosis of LGGs.

IDH1 gene mutations identify gliomas with a distinct molecular evolutionary origin. We sought to determine the impact of surgical resection on survival after controlling for IDH1 status in malignant astrocytomas-World Health Organization grade III anaplastic astrocytomas and grade IV glioblastoma.Clinical parameters including volumetric assessment of preoperative and postoperative MRI were recorded prospectively on 335 malignant astrocytoma patients: n = 128 anaplastic astrocytomas and n = 207 glioblastoma. IDH1 status was assessed by sequencing and immunohistochemistry.IDH1 mutation was independently associated with complete resection of enhancing disease (93% complete resections among mutants vs 67% among wild-type, P.001), indicating IDH1 mutant gliomas were more amenable to resection. The impact of residual tumor on survival differed between IDH1 wild-type and mutant tumors. Complete resection of enhancing disease among IDH1 wild-type tumors was associated with a median survival of 19.6 months versus 10.7 months for incomplete resection; however, no survival benefit was observed in association with further resection of nonenhancing disease (minimization of total tumor volume). In contrast, IDH1 mutants displayed an additional survival benefit associated with maximal resection of total tumor volume (median survival 9.75 y for5 cc residual vs not reached for5 cc, P = .025).The survival benefit associated with surgical resection differs based on IDH1 genotype in malignant astrocytic gliomas. Therapeutic benefit from maximal surgical resection, including both enhancing and nonenhancing tumor, may contribute to the better prognosis observed in the IDH1 mutant subgroup. Thus, individualized surgical strategies for malignant astrocytoma may be considered based on IDH1 status.

The efficacy of glucocorticoid for treatment of acute spinal cord injuries remains a controversial topic. Differing medical societies have issued conflicting recommendations in this regard. Here we review the available randomized, controlled trial (RCT) data on this subject and offer a synthesis of these data sets.