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Background Five to ten percent of the global population have unruptured intracranial aneurysms, and ruptured brain aneurysms cause approximately 500,000 deaths a year. Flow-diverting stent treatment is a less invasive intracranial aneurysm treatment that induces aneurysm thrombosis. The imaging characteristics of a novel primarily bioresorbable flow-diverting stent (BFDS) are assessed in comparison to the leading metal stent using fluoroscopy, CT, and MRI. Methods X-ray/fluoroscopic images of stents were taken using a human cadaveric skull model. CT and MRI were acquired using silicone flow models of residual aneurysms. Images were analyzed with Likert scales in anonymous surveys by neurointerventionalists. Quantitative measurements of radiographic density (CT) and artifact boundary size (CT & MRI) were also obtained. Results Visibility of the BFDS on X-ray was less than the metal stent but deemed adequate for deployment and intraprocedural assessment. The metal stent was more radiopaque than the BFDS on CT, but qualitative assessment was not significantly different for the two stents. MRI imaging was significantly better using the BFDS in terms of overall artifact and intraluminal assessment. Conclusions The BFDS has adequate visualization on X-ray/fluoroscopy and should be clinically acceptable for fluoroscopic deployment. On MRI, there is less quantitative artifact as well as overall improved qualitative assessment that will allow for more detailed non-invasive imaging follow-up of treated aneurysms, potentially reducing the need for digital subtraction catheter angiography.

OBJECTIVE Routine antiplatelet responsiveness testing for patients undergoing carotid artery stenting procedures is not performed at most endovascular centers and remains a topic of controversy within the neurointerventional community. The objective of this study was to determine if nonresponsiveness to acetylsalicylic acid or clopidogrel was associated with the development of symptomatic thromboembolic events in patients undergoing carotid stenting procedures. METHODS A prospective study was conducted at the Foothills Medical Centre in Calgary, Alberta, Canada, from August 2019 to July 2021. Patients undergoing carotid artery stenting procedures and who were receiving dual antiplatelet therapy were enrolled in the study. Responsiveness to the antiplatelet medications was determined through whole blood impedance aggregometry. The primary outcome was development of a symptomatic thromboembolic event within 90 days after the procedure. The treating physicians were blinded to the aggregometry results for the duration of the study. RESULTS One hundred two procedures were performed in 100 patients. Eight thromboembolic events (8%) occurred during the study. Age (p = 0.03) and nonresponsiveness to clopidogrel (p = 0.003) were associated with the development of thromboembolic events. The multivariable model showed that clopidogrel nonresponsiveness was independently associated with the development of a thromboembolic event (adjusted OR 6.14, 95% CI 1.25–30.11, p = 0.03). CONCLUSIONS This study demonstrated that patients who were identified as clopidogrel nonresponders, using whole blood impedance aggregometry, were at an increased risk of developing thromboembolic events. Larger studies are needed to assess the utility of routine platelet function testing prior to carotid artery stenting procedures.

OBJECTIVE Flow-diverting stents with a resorbable component have significant theoretical benefits over full metal stents, although currently there are none in clinical use. In this study, the authors sought to determine the immediate flow-diversion characteristics of a novel primarily bioresorbable flow-diverting stent. METHODS Bioresorbable stents were deployed into glass tube models to determine porosity and pore density. In vitro flow diversion behavior was evaluated using high frame rate angiography under pulsatile flow conditions in a patient-specific silicone aneurysm model treated with the resorbable stent as well as the Surpass Evolve stent. In vivo flow diversion was characterized by deployment into 20 rabbit saccular aneurysm models, and grading was based on the O’Kelly-Marotta scale and the 4F-flow diversion predictive score. RESULTS Porosities and pore densities of the bioresorbable stent were in the flow-diverting range for all target vessel diameters. Quantified results of immediate angiography after placement of the bioresorbable stent into a silicone aneurysm model demonstrated greater flow diversion compared to the Evolve stent. Bioresorbable stent placement in saccular aneurysm models resulted in an immediate O’Kelly-Marotta grade of A3 or better and a 4F-flow diversion predictive score of 4 or better in all cases. CONCLUSIONS The bioresorbable stent has immediate flow-diversion characteristics that are comparable to commercially available metal stents. Longer-term studies are underway to determine the ability of the resorbable fibers to act as a neointimal scaffold and result in long-term aneurysm occlusion.

OBJECTIVE Flow diverters have revolutionized the endovascular treatment of intracranial aneurysms. Here, the authors present the first large-scale North American multicenter experience using the Flow Redirection Endoluminal Device (FRED) in the treatment of cerebral aneurysms. METHODS Consecutive cerebral aneurysms treated with FRED at 7 North American centers between June 2020 and November 2021 were included. Data collected included patient demographic characteristics, aneurysm characteristics, periprocedural and long-term complications, modified Rankin Scale (mRS) scores, and radiological follow-up. RESULTS In total, 133 aneurysms in 116 patients were treated with 123 FRED deployment procedures and included in this study. One hundred twenty-six aneurysms (94.7%) were unruptured, 117 (88.0%) saccular, and 123 (92.5%) located in anterior circulation. The mean (range) aneurysm maximal width and neck width sizes were 7.2 (1.5–42.5) mm and 4.1 (1.0–15.1) mm, respectively. Successful FRED deployment was achieved in 122 procedures (99.2%). Adjunctive coiling was used in 4 procedures (3.3%). Radiological follow-up was available for 101 aneurysms at a median duration of 7.0 months. At last follow-up, complete occlusion was observed in 55.4% of patients, residual neck in 8.9%, and filling aneurysm in 35.6%; among cases with radiological follow-up duration > 10 months, these values were 21/43 (48.8%), 3/43 (7.0%), and 19/43 (44.2%), respectively. On multivariate regression analysis, age (OR 0.93, p = 0.001) and aneurysm neck size (OR 0.83, p = 0.048) were negatively correlated with odds of complete occlusion at latest follow-up. The retreatment rate was 6/124 (4.8%). The overall complication rate was 31/116 (26.7%). Parent vessel occlusion, covered branch occlusion, and in-stent stenosis were detected in 9/99 (9.1%), 6/63 (9.5%), and 15/99 (15.2%) cases, respectively. The FRED-related, symptomatic, thromboembolic, and hemorrhagic complication rates were 22.4%, 12.9%, 6.9%, and 0.9% respectively. The morbidity rate was 10/116 patients (8.6%). There was 1 death due to massive periprocedural internal carotid artery stroke, and 3.6% of the patients had an mRS score > 2 at the last follow-up (vs 0.9% at baseline). CONCLUSIONS As the first large-scale North American multicenter FRED experience, this study confirmed the ease of successful FRED deployment but suggested lower efficacy and a higher rate of complications than reported by previous European and South American studies on FRED and other flow-diverting devices. The authors recommend judicious use of this device until future studies can better elucidate the long-term outcomes of FRED treatment.

BackgroundFlow-diverting stents are not currently indicated for the treatment of bifurcation aneurysms, and some case series have demonstrated low occlusion rates, possibly due to a lack in neck coverage. The ReSolv stent is a unique hybrid metal/polymer stent that can be deployed with the shelf technique in order to improve neck coverage.MethodsA Pipeline, unshelfed ReSolv, and shelfed ReSolv stent were deployed in the left-sided branch of an idealized bifurcation aneurysm model. After determining stent porosity, high-speed digital subtraction angiography runs were acquired under pulsatile flow conditions. Time–density curves were created using two region of interest (ROI) paradigms (total aneurysm and left/right), and four parameters were extracted to characterize flow diversion performance.ResultsThe shelfed ReSolv stent demonstrated better aneurysm outflow alterations compared to the Pipeline and unshelfed ReSolv stent when using the total aneurysm as the ROI. On the left side of the aneurysm, there was no significant difference between the shelfed ReSolv stent and the Pipeline. On the right side of the aneurysm, however, the shelfed ReSolv stent had a significantly better contrast washout profile than the unshelfed ReSolv stent and the Pipeline stent.ConclusionsThe ReSolv stent with the shelf technique demonstrates the potential to improve flow diversion outcomes for bifurcation aneurysms. Further in vivo testing will help to determine whether the additional neck coverage leads to better neointimal scaffolding and long-term aneurysm occlusion.

Background: Most patients with World Federation of Neurological Surgeons (WFNS) grade 5 subarachnoid hemorrhage (SAH) have poor outcomes. Accurate assessment of prognosis is important for treatment decisions and conversations with families regarding goals of care. Unjustified pessimism may lead to “self-fulfilling prophecy,” where withdrawal of life-sustaining measures (WLSM) is invariably followed by death. Methods: We performed a cohort study involving consecutive patients with WFNS grade 5 SAH to identify variables with >= 90% and >= 95% positive predictive value (PPV) for poor outcome (1-year modified Rankin Score >= 4), as well as findings predictive of WLSM. Results: Of 140 patients, 38 (27%) had favorable outcomes. Predictors with >= 95% PPV for poor outcome included unconfounded 72-hour Glasgow Coma Scale motor score = 1 pupillary light reflex (PLR) at 24 hours, and intraventricular hemorrhage (IVH) score of >= 20 (volume >= 54.6 ml). Intracerebral hemorrhage (ICH) volume >= 53 ml had PPV of 92%. Variables associated with WLSM decisions included a poor motor score (p < 0.0001) and radiographic evidence of infarction (p = 0.02). Conclusions: We identified several early predictors with high PPV for poor outcome. Of these, lack of improvement in motor score during the initial 72 hours had the greatest potential for confounding from “self-fulfilling prophecy.” Absence of PLR at 24 hours, IVH score >= 20, and ICH volume >= 53 ml predicted poor outcome without a statistically significant effect on WLSM decisions. More research is needed to validate prognostic variables in grade 5 SAH, especially among patients who do not undergo WLSM.

Intracranial flow-diverting (FD) stents have revolutionized the treatment of intracranial aneurysms in recent years, but complications resulting from failed endothelialization can still occur. Approaches to promote endothelialization are understudied, but hold promise in mitigating both short- and long-term complications associated with FD stent insertion. The aim of this review is to highlight the various features of and modifications that have been made to FD stents in order to expedite endothelialization. More specifically, we focus on how endothelialization can be influenced by the stent design, wall apposition, surface modifications, and the inclusion of biological agents.

OBJECTIVE Delayed neointima formation over a neurovascular stent is associated with thrombotic complications that can lead to stroke. The purpose of this study was to evaluate whether an intra-arterial injection of mesenchymal stem cells (MSCs) after stent placement leads to improved neointima and reduced thrombus formation over the device. METHODS Solitaire stents were placed into the aortas of rabbits that were divided into MSC and control groups. The MSC group received an intra-arterial injection of MSCs through the same microcatheter used for stent deployment. Optical coherence tomography (OCT) was used to evaluate and compare neointima and thrombus formation in a blinded fashion. Explanted specimens were also imaged with scanning electron microscopy (SEM) and evaluated by observers blinded to group allocation using an endothelialization scoring system. RESULTS The 3-day MSC group was similar to the 7-day controls in terms of stent strut coverage ratio and maximum neointimal thickness, but these values were significantly higher than the 3-day control group based on a hierarchical mixed-effects linear regression analysis. SEM revealed a significantly higher endothelialization score for the MSC group compared with controls at the same time point. There was no difference in thrombus formation between any of the groups. CONCLUSIONS The intra-arterial injection of MSCs after endovascular stenting accelerated early neointima formation but had no effect on thrombus formation in this study. Larger studies are required to verify these findings and determine the durability and mechanism of this effect.

Physiologically relevant intracranial aneurysm (IA) models are crucially required to facilitate testing treatment options for IA. Herein, we report the development of a new in vitro tissue-engineered platform, which recapitulates the microenvironment, structure, and cellular complexity of native human IA. A new modified liquid-assisted injection molding technique was developed to fabricate a three-dimensional hollow IA model with clinically relevant IA dimensions within a mechanically tuned Gelatin Methacryloyl (GelMA) hydrogel. An endothelium lining was created inside the IA model by culturing human umbilical vein endothelial cells over pre-cultured human brain vascular smooth muscle cells. These cellularized IA models were subjected to medium perfusion at flow rates between 6.3 and 15.75 mL/min for inducing biomimetic vessel wall shear stress (10–25 dyn/cm2) to the cells for ten days. Both cell types maintained their secretome profiles and showed more than 96% viability, demonstrating the biocompatibility of the hydrogel during perfusion cell culture at such flow rates. Based on the characterized viscoelastic properties of the GelMA hydrogel and with the aid of a fluid-structure interaction model, the capability of the IA model in predicting the response of the IA to different fluid flow profiles was mathematically shown. With physiologically relevant behavior, our developed in vitro human IA model could allow researchers to better understand the pathophysiology and treatment of IA. Statement of significance A three-dimensional intracranial aneurysm (IA) tissue model recapitulating the microenvironment, structure, and cellular complexity of native human IA was developed. • An endothelium lining was created inside the IA model over pre-cultured human brain vascular smooth muscle cells over at least 10-day successful culture. • The cells maintained their secretome profiles, demonstrating the biocompatibility of hydrogel during a long-term perfusion cell culture. • The IA model showed its capability in predicting the response of IA to different fluid flow profiles. • The cells in the vessel region behaved differently from cells in the aneurysm region due to alteration in hemodynamic shear stress. • The IA model could allow researchers to better understand the pathophysiology and treatment options of IA.

Epidural fat is commonly discarded during spine surgery to increase the operational field. However, mesenchymal progenitor cells (MPCs) have now been identified in human epidural fat and within the murine dura mater. This led us to believe that epidural fat may regulate homeostasis and regeneration in the vertebral microenvironment. Using two MPC lineage tracing reporter mice (Prx1 and Hic1), not only have we found that epidural fat MPCs become incorporated in the dura mater over the course of normal skeletal maturation, but have also identified these cells as an endogenous source of repair and regeneration post-dural injury. Moreover, our results reveal a partial overlap between Prx1+ and Hic1+ populations, indicating a potential hierarchical relationship between the two MPC populations. This study effectively challenges the notion of epidural fat as an expendable tissue and mandates further research into its biological function and relevance.

Purpose: To describe a standardized orbital resection technique and outcomes for spheno-orbital meningiomas with soft-tissue invasion of the orbit. Methods: A retrospective case review of patients with spheno-orbital meningioma that underwent resection utilizing the Alberta Standardized Orbital Technique (ASOT) between 2008 and 2017 was performed. Results: Twenty patients met the inclusion criteria. Fifteen females and five males, with an average age of 53.4 years (SD ± 13.1 years). Mean follow-up was 57.3 months (SD ± 29.5 months). Eight cases (40%) had attempted resection prior to referral. Based on pre-operative plan, patients were divided into two groups based on goal of resection. Of those with planned complete resection (Group I), 11/13 patients (84.6%) underwent complete excision, with no cases of orbital recurrence. Incomplete resection in two cases occurred because of unexpected involvement of critical intra-cranial structures. Thus, in total 9/20 patients (Group II and 2 from Group I) underwent subtotal resection. Of these incomplete resections, five cases of orbital recurrence were observed; four patients required adjuvant external beam radiotherapy (EBRT) and one patient underwent further debulking surgery. Orbital control was achieved in three of these recurrent cases. Complications reported were persistent postoperative diplopia (three cases/15%) and wound infection (one case/5%). Overall, stable orbital disease was obtained in 18 patients (90%). Conclusion: The ASOT demonstrated to be effective, achieving the pre-operative plan of complete resection in 11/13 cases (84.6%) with no recurrence in those with clear orbital margins.

BackgroundSimulation training has been used in the aviation industry and surgical specialties for many years, but integration into neurointerventional practice is lagging behind.ObjectiveTo investigate how neurointerventionalists perceive the usefulness and limitations of simulation tools for the treatment of unruptured intracranial aneurysms (UIAs), and to identify simulation applications that were perceived to be most valuable for endovascular UIA treatment.MethodsA web-based international multidisciplinary survey was conducted among neurointerventionalists. Participants were asked for their perceptions on the usefulness of current simulation tools and the potential impact of future simulation tools in endovascular UIA treatment. They identified simulation applications that could add most value to endovascular UIA treatment and help to specifically reduce endovascular UIA treatment complications.Results233 neurointerventionalists from 38 countries completed the survey, most of whom (157/233 (67.4%)) had access to a simulator as a trainee, but only 15.3% used it frequently. Most participants (117/233 (50.2%)) considered currently available simulation tools relatively useful for endovascular UIA treatment, with greater value for trainees than for staff. Simulation of new devices (147/233 (63.1%)) and virtual practice runs in individual patient anatomy (119/233 (51.1%)) were considered most valuable for reducing endovascular UIA treatment complications.ConclusionAlthough neurointerventionalists perceived currently available simulation tools relatively useful, they did not use them regularly during their training. A priori testing of new devices and practice runs in individual patient anatomy in a virtual environment were thought to have the greatest potential for reducing endovascular UIA treatment complications.

IntroductionDural venous sinus stenosis (DVSS) may lead to increased intracranial pressure, sometimes requiring a stent if a high pressure gradient exists. Many neuroendovascular physicians use microcatheters to measure gradients, yet there are no studies comparing the accuracies and precisions of modern day microcatheters. We examined pressure recordings from five commonly used microcatheters in an experimental DVSS model.MethodsUsing a programmable pump, dynamic flow was established in a closed circuit mimicking the venous sinus waveform. Microcatheters with 150 cm effective lengths were connected proximally to pressure transducers. Mean recording pressures were compared with a high fidelity microcatheter (HFM) in several configurations including no stenosis, proximal to a focal stenosis, and distal to a focal stenosis in opposing orientations.ResultsAll microcatheters recorded lower pressures than the HFM. Three of the five microcatheters successfully met intracranial pressure monitoring device standards in all conditions, while one did not meet standards in any configuration. The performance of the final microcatheter was variable, with inaccuracies occurring in unrestricted flow. All microcatheters demonstrated relatively high precision, but with variable accuracies. The larger diameter microcatheters displayed the least damping and therefore the greatest accuracies. Of the three smaller microcatheters, dimensions did not predict performance, suggesting that microcatheter construction may also play a role in pressure accuracy.ConclusionThe use of microcatheters to record dural venous sinus pressures must be done with an understanding of the inherent limitations and inaccuracies, especially if clinical decisions are made from the results.

IntroductionThe advent of metal flow-diverting stents has provided neurointerventionalists with an option for treating aneurysms without requiring manipulations within the aneurysm sac. The large amount of metal in these stents, however, can lead to early and late thrombotic complications, and thus requires long-term antiplatelet agents. Bioabsorbable stents have been postulated to mitigate the risk of these complications. Here we present early data on the first self-expandable primarily bioabsorbable stent for aneurysms.MethodsBraided stents were developed using poly-L-lactic acid fibers with material surface area similar to metal flow diverters. Crush resistance force, hemolysis, and thrombogenicity were determined and compared with existing commercial devices. Stents were deployed in infra-renal rabbit aortas to determine angiographic side branch patency and to study neointima formation for a 1-month follow-up period.ResultsCrush resistance force was determined to be on the order of existing commercial devices. Hemolytic behavior was similar to existing metal devices, and thrombogenicity was lower than metal flow-diverting stents. A smooth neointimal layer was found over the absorbable stent surface and all covered side branches were patent at follow-up.ConclusionThe design of self-expanding primarily bioabsorbable flow-diverting stents is possible, and preliminary safety data is consistent with a favorable profile in terms of mechanical behavior, hemocompatibility, side branch patency, and histological effects. Additional in vitro and long-term in vivo studies are in progress and will help determine aneurysm occlusion rates and absorption characteristics of the stent.

ObjectiveThe only pharmacologic prophylaxis for cerebral vasospasm after subarachnoid hemorrhage is oral nimodipine. A novel way to mitigate this risk may be to design a drug eluting stent that elutes verapamil over the time period typically associated with vasospasm. In this study, we explore different methods of coating nitinol stents with a bioabsorbable polymer and determine the release profile of various verapamil coated stents for the potential treatment of vasospasm.MethodsNitinol stents were coated with different concentrations of poly(lactic acid-co-glycolic acid) (PLGA) in chloroform solution and using three coating techniques: dip coating, spin coating, and electrospinning. Morphology of the coatings were studied with scanning electron microscopy. 12 verapamil eluting stents were then prepared using different verapamil concentrations and coatings with different numbers of layers. Drug release behaviors were studied using UV spectroscopy for 21 days.ResultsElectrospinning at 20% w/v resulted in a smooth uniform coating without significant surface irregularities, and may be the most effective technique to coat stents. Stents with a single layer of PLGA/verapamil coating showed a two phase release profile (initial burst release followed by a slow rate of release) whereas stents with a bilayer coating showed a lower level of initial release followed by a slower sustained release phase.ConclusionsDevelopment of verapamil eluting stents that elute drug over the time course typical of cerebral vasospasm, and for either immediate or prophylactic treatment, is technically feasible. Further in vitro and in vivo studies are required to determine whether this can improve the outcome of patients after subarachnoid hemorrhage.

ObjectiveTo assess the feasibility and efficacy of clinically translatable adjuvant mesenchymal stem/stromal cells (MSCs) therapy in improving the healing of coiled aneurysms in a rabbit elastase aneurysm model.MethodsBone marrow-derived MSC populations were isolated from three rabbit donors in a serum-free environment and independently characterized to confirm their identity. Elastase-induced carotid aneurysms were created in nine New Zealand white rabbits. Each animal received one of the following treatments based on previous randomization: (1) coiling alone (control group); (2) coiling with an intra-aneurysmal injection of saline (vehicle group); and (3) coiling with an intra-aneurysmal injection of 5 million allogeneic MSCs (treatment group). The animals were followed for 4 weeks post-treatment, at the end of which blinded analyses of angiograms and histology were performed.ResultsHistological results in the treatment group showed improvements over the control and vehicle groups, although the improvement over the vehicle group was not significant. Intra-aneurysmal cell therapy with 5 million allogeneic MSCs did not result in any major adverse events. Angiographic results did not show any significant difference among groups.ConclusionsThis proof-of-concept study shows that adjuvant MSC therapy for intracranial aneurysms is feasible and may enhance histological improvement of coiled aneurysms at 4 weeks post-treatment.

OBJECTIVEReliable animal models are an important aspect of translational research, especially for relatively uncommon clinical entities such as fusiform aneurysms. While several animal models exist, very few are tailored to cerebral fusiform aneurysms, which have unique attributes compared to abdominal fusiform aneurysms. The authors aimed to build from previous models to create a cerebral fusiform aneurysm model that is simple to use and reliable.METHODSTwelve female New Zealand White rabbits were assigned to 3 groups: group E, elastase only; group C, CaCl2 only; group EC, elastase + CaCl2. All rabbits underwent surgical exposure of the right common carotid artery (CCA) and 20 minutes of peri-carotid incubation with their respective chemicals. Angiography was performed 6 weeks later for arterial dilation measurements, with 50% increase in diameter being defined as fusiform aneurysm formation. The arterial segments, along with the contralateral CCAs, were harvested and assessed histologically for wall component measurements and elastin semiquantification. A separate rabbit underwent aneurysm creation per the group EC protocol and was treated with an endovascular flow-diversion device.RESULTSAll of the group EC rabbits developed fusiform aneurysms (mean dilation of 88%), while none of the group E or group C rabbits developed aneurysms (p = 0.001). Histological analysis revealed increased internal elastic lamina fragmentation in the group EC aneurysms, which also had less tunica intima hyperplasia. All aneurysms exhibited thinning of the tunica media and reduction in elastin content. The use of an endovascular flow-diverting stent was successful, with complete parent vessel remodeling, as expected, 4 weeks after deployment.CONCLUSIONSThe peri-arterial application of combined elastase and CaCl2 to the CCA appears sufficient to reliably produce fusiform aneurysms after 6 weeks. Exposure to elastase or CaCl2 individually appears insufficient, despite the observed histological changes to the arterial wall. The proposed fusiform aneurysm model is able to accommodate endovascular devices, simulating the tortuous pathway experienced in using such devices in human cerebral aneurysms and thus is a satisfactory model to use in translational research.

Among patients with a proximal vessel occlusion in the anterior circulation, 60 to 80% of patients die within 90 days after stroke onset or do not regain functional independence despite alteplase treatment. We evaluated rapid endovascular treatment in addition to standard care in patients with acute ischemic stroke with a small infarct core, a proximal intracranial arterial occlusion, and moderate-to-good collateral circulation. Methods We randomly assigned participants to receive standard care (control group) or standard care plus endovascular treatment with the use of available thrombectomy devices (intervention group). Patients with a proximal intracranial occlusion in the anterior circulation were included up to 12 hours after symptom onset. Patients with a large infarct core or poor collateral circulation on computed tomography (CT) and CT angiography were excluded. Workflow times were measured against predetermined targets. The primary outcome was the score on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) at 90 days. A proportional odds model was used to calculate the common odds ratio as a measure of the likelihood that the intervention would lead to lower scores on the modified Rankin scale than would control care (shift analysis). Results The trial was stopped early because of efficacy. At 22 centers worldwide, 316 participants were enrolled, of whom 238 received intravenous alteplase (120 in the intervention group and 118 in the control group). In the intervention group, the median time from study CT of the head to first reperfusion was 84 minutes. The rate of functional independence (90-day modified Rankin score of 0 to 2) was increased with the intervention (53.0%, vs. 29.3% in the control group; P

Endovascular embolization is the standard approach for management of carotid cavernous fistulas (CCFs) due to the ease of access and reduced level of risk associated with the procedure compared with open surgery. We present here a case of a CCF that eventually led to the development of brainstem venous congestion from perimedullary venous drainage. This fistula was not amenable to endovascular embolization due to lack of either ophthalmic vein or petrosal sinus drainage. Therefore, a craniotomy with direct puncture of the cavernous sinus was performed, followed by coil embolization to completely treat this fistula. This case demonstrates an uncommon progression of venous drainage to Cognard grade V, rare development of symptomatic brainstem venous congestion and a unique method to combine an open surgical approach with endovascular embolization to treat CCFs.

A 62-year-old woman presented with a subarachnoid hemorrhage secondary to a ruptured right supraclinoid internal carotid artery blister aneurysm. She was treated in an emergent fashion with two flow diverting pipeline embolization devices (PED) deployed in a telescoping fashion. CT angiography performed for unrelated reasons at 7 months showed successful treatment of the aneurysm without evidence of residual aneurysm. However, a follow-up digital subtraction angiogram performed at 9 months showed a large aneurysm in a modified position compared with the original aneurysm. This is the first case of rapid regrowth of a supraclinoid blister aneurysm after successful treatment with a PED, and demonstrates the need for close follow-up for similar aneurysms treated with this novel device.

A 62-year-old woman presented with a subarachnoid hemorrhage secondary to a ruptured right supraclinoid internal carotid artery blister aneurysm. She was treated in an emergent fashion with two flow diverting pipeline embolization devices (PED) deployed in a telescoping fashion. CT angiography performed for unrelated reasons at 7 months showed successful treatment of the aneurysm without evidence of residual aneurysm. However, a follow-up digital subtraction angiogram performed at 9 months showed a large aneurysm in a modified position compared with the original aneurysm. This is the first case of rapid regrowth of a supraclinoid blister aneurysm after successful treatment with a PED, and demonstrates the need for close follow-up for similar aneurysms treated with this novel device.

OBJECTIVE Blunt cerebrovascular injury (BCVI) occurs in approximately 1% of the blunt trauma population and may lead to stroke and death. Early vascular imaging in asymptomatic patients at high risk of having BCVI may lead to earlier diagnosis and possible stroke prevention. The objective of this study was to determine if the implementation of a formalized asymptomatic BCVI screening protocol with CT angiography (CTA) would lead to improved BCVI detection and stroke prevention. METHODS Patients with vascular imaging studies were identified from a prospective trauma registry at a single Level 1 trauma center between 2002 and 2008. Detection of BCVI and stroke rates were compared during the 3-year periods before and after implementation of a consensus-based asymptomatic BCVI screening protocol using CTA in 2005. RESULTS A total of 5480 patients with trauma were identified. The overall BCVI detection rate remained unchanged postprotocol compared with preprotocol (0.8% [24 of 3049 patients] vs 0.9% [23 of 2431 patients]; p = 0.53). However, postprotocol there was a trend toward a decreased risk of stroke secondary to BCVI on a trauma population basis (0.23% [7 of 3049 patients] vs 0.53% [13 of 2431 patients]; p = 0.06). Overall, 75% (35 of 47) of patients with BCVI were treated with antiplatelet agents, but no patient developed new or progressive intracranial hemorrhage despite 70% of these patients having concomitant traumatic brain injury. CONCLUSIONS The results of this study suggest that a CTA screening protocol for BCVI may be of clinical benefit with possible reduction in ischemic complications. The treatment of BCVI with antiplatelet agents appears to be safe.

Object Recurrence after endovascular coiling of intracranial aneurysms is reported in up to 42% of cases and is attributed to the lack of endothelialization across the neck. In this study the authors used a novel tissue engineering approach to promote endothelialization by seeding endothelial progenitor cells (EPCs) within a fibrin polymer injected endovascularly into the aneurysm. Methods Experimental aneurysms were created in New Zealand White rabbits and were left untreated, surgically clipped, or embolized with platinum coils, fibrin biopolymer alone, or fibrin combined with autologous cultured EPCs. Results In aneurysms treated with EPCs, a confluent monolayer of endothelial cells with underlying neointima was demonstrated across the neck at 16 weeks posttreatment, which was not observed with aneurysms treated using the other methods. Conclusions This novel technique may address reasons for the limited durability of standard coil embolization and provides further avenues for the development of improved devices for the care of patients with aneurysms.

Background Cerebral venous sinus thrombosis (CVT) is an uncommon cause of stroke that is usually treated medically with intravenous heparin therapy followed by long-term anticoagulation therapy. A series of patients with CVT who underwent rheolytic thrombectomy with the AngioJet as a first-line adjunctive treatment in addition to standard anticoagulation therapy is presented. Methods Prospectively maintained endovascular databases at two institutions were retrospectively reviewed. The available clinical and imaging data were compiled at each institution and combined for analysis. Results Over 18 months, 13 patients (seven women and six men; age range 17–73 years, median age 45 years) with CVT were treated with rheolytic thrombectomy. Immediate (partial or complete) recanalization of the thrombosed intracranial sinuses was achieved in all patients. At a median radiographic follow-up of 7 months there was continued patency of all recanalized sinuses. Clinical follow-up was available on nine patients: modified Rankin score of 0 in four patients, 1 in three patients and 6 in two patients. Conclusion This series demonstrates the feasibility of performing mechanical thrombectomy as a first-line treatment for acute CVT. This technique facilitates the prompt restoration of intracranial venous outflow, which may result in rapid neurological and symptomatic improvement.

Object The management of intramedullary spinal cord cavernous malformations (CMs) is controversial. At Barrow Neurological Institute, the authors selectively offer surgical treatment for symptomatic spinal cord CMs. The purpose of this paper is to review the clinical outcomes in patients after resection of these lesions based on a single-center experience over a 25-year period. Methods The records of 80 patients who underwent resection of pathologically confirmed spinal cord CMs from January 1985 to May 2010 were analyzed retrospectively. Preoperative clinical status and imaging findings were evaluated as well as immediate and long-term postoperative outcomes. Results Compared with their preoperative Frankel grade, 11% of patients were worse, 83% were the same, and 6% improved immediately after surgery. At a mean follow-up interval of 5 years, 10% of patients were worse, 68% were the same, and 23% were improved compared with their preoperative status. Five percent of patients underwent reoperation for resection of a symptomatic residual or recurrent lesion. Immediate complications were encountered in 6% of patients, including CSF leakage and deep venous thrombosis. Long-term complications were encountered in 14% of patients and included kyphotic deformity, stenosis, and spinal cord tethering. A significant correlation was found between long-term outcome and anteroposterior length of the lesion (p = 0.01). Conclusions The resection of intramedullary spinal cord CMs can be achieved with good long-term outcomes and an acceptable risk of immediate or delayed complications.

Orbital lymphaticovenous malformations (LVM) are congenital vascular lesions that are typically infiltrative in nature. There have been reports of orbital LVMs extending intracranially through orbital fissures, but there have been no reports of intradural extension that we are aware of. We present the case of an otherwise healthy 25-year-old female with an orbital LVM extending intradurally. Imaging revealed an intraorbital lesion extending through a bony defect in the medial orbital roof to the orbitofrontal cortex. A modified orbitozygomatic approach was used to obliterate this lesion. A durotomy was created to examine the intradural extension of the lesion, which appeared as a lobulated red vascular structure emanating from the dura along the roof of the orbit. This was gradually and comprehensively bipolar coagulated and subsequently obliterated. Neurosurgical and ophthalmological collaboration was used in the surgical management of this case. In summary, we report the first case of an orbital LVM extending intradurally, and provide pre and post-operative imaging as well as images captured through the intraoperative microscope. Through this case we highlight the importance of an interdisciplinary approach when managing orbital LVMs, as both ophthalmological and neurosurgical expertise were critical in the success of the surgery.

Macrocephaly-cutis marmorata telangiectatica congenita is a rare overgrowth syndrome commonly associated with hydrocephalus. Although the pathophysiological characteristics of the hydrocephalus in this syndrome is not fully known, previous reports have described its treatment with ventriculoperitoneal shunt placement. The authors describe 2 cases of macrocephaly-cutis marmorata telangiectatica congenita successfully treated for progressive hydrocephalus with endoscopic third ventriculostomy. Both patients experienced clinical and radiographic stabilization following treatment, and these findings offer insight into the pathophysiology of the hydrocephalus and its ideal management.

The PS Medical Strata valve is a programmable shunt valve used in the treatment of hydrocephalus that allows for noninvasive changes in the pressure setting using a magnet. The Strata valve is sensitive to magnetic fields, and reprogramming is frequently necessary after MR imaging. A known but rare complication of the Strata valve is that the rotor can become locked, causing shunt malfunction. This complication can only occur in a first generation Strata valve.

In acute ischemic stroke, good outcome following successful recanalization is time dependent. In patients undergoing endovascular therapy at our institution, recanalization times with the Solitaire stent were retrospectively evaluated to assess for the presence of a learning curve in achieving rapid recanalization.We reviewed patients who presented to our stroke center and achieved successful recanalization with the Solitaire stent exclusively. Time intervals were calculated (CT to angiography arrival, angiography arrival to groin puncture, groin puncture to first deployment, and deployment to recanalization) from time stamped images and angiography records. Patients were divided into three sequential groups, with overall CT to recanalization time and subdivided time intervals compared.83 patients were treated with the Solitaire stent from May 2009 to February 2012. Recanalization (Thrombolyis in Cerebral Infarction score 2A) occurred in 75 (90.4%) patients. CT to recanalization demonstrated significant improvement over time, which was greatest between the first 25 and the most recent 25 cases (161-94 min; p0.01). The maximal contribution to this was from improvements in first stent deployment to recanalization time (p=0.001 between the first and third groups), with modest contributions from moving patients from CT to the angiography suite faster (p=0.02 between the first and third groups) and from groin puncture to first stent deployment (p=0.02 between the first and third groups).There is a learning curve involved in the efficient use of the Solitaire stent in endovascular acute stroke therapy. Along with improvements in patient transfer to angiography and improved efficiency with intracranial access, mastering this device contributed significantly towards reducing recanalization times.

A 42-year-old farmer was lifting a hay bale and experienced a sudden onset of sharp pain radiating down his left leg. Over the ensuing week, the pain became less pronounced, but was replaced with a progressive left greater than right leg numbness, foot weakness, and urinary hesitancy. He presented to his local hospital, where he was initially managed conservatively, and then transferred to our institution for consultation after an MR lumbar spine was completed. On physical exam, he had grade 1/5 weakness of left and right dorsi- and plantar flexion. Sensory testing showed a moderate decrease in pinprick sensation in his left leg from L1 to S1 dermatomes. He was symmetrically hyporeflexic with grade 1 knee reflexes and absent ankle jerks. Peri-anal sensation was intact, but there was moderately reduced rectal tone. The remainder of his neurological exam was normal.

Brainstem cavernous malformations (CMs) are low-flow vascular lesions in eloquent locations. Their presentation is often marked with symptomatic hemorrhages that appear to occur more frequently than hemorrhage from supratentorial cavernomas. Brainstem CMs can be removed using 1 of the 5 standard skull-base approaches: retrosigmoid, suboccipital (with or without telovelar approach), supracerebellar infratentorial, orbitozygomatic, and far lateral. Patients being referred to a tertiary institution often have lesions that are aggressive with respect to bleeding rates. Nonetheless, the indications for surgery, in the authors' opinion, are the same for all lesions: those that are symptomatic, those that cause mass effect, or those that abut a pial surface. Patients often have relapsing and remitting courses of symptoms, with each hemorrhage causing a progressive and stepwise decline. Many patients experience new postoperative deficits, most of which are transient and resolve fully. Despite the risks associated with operating in this highly eloquent tissue, most patients have had favorable outcomes in the authors' experience. Surgical treatment of brainstem CMs protects patients from the potentially devastating effects of rehemorrhage, and the authors believe that the benefits of intervention outweigh the risks in patients with the appropriate indications.

Object Imaging of intracranial aneurysms using conventional multidetector CT (MDCT) is limited because of nonvisualization of features such as perforating vessels, pulsatile blebs, and neck remnants after clip placement or coil embolization. In this study, a model of intracranial saccular aneurysms in rabbits was used to assess the ultra-high resolution and dynamic scanning capabilities of a prototype flat-panel volumetric CT (fpVCT) scanner in demonstrating these features. Methods Ten New Zealand white rabbits underwent imaging before and after clipping or coil embolization of surgically created aneurysms in the proximal right carotid artery. Imaging was performed using a prototype fpVCT scanner, a 64-slice MDCT scanner, and traditional catheter angiography. In addition to the slice data and 3D views, 4D dynamic views, a capability unique to fpVCT, were also created and reviewed. The images were subjectively compared on 1) 4 image quality metrics (spatial resolution, noise, motion artifacts, and aneurysm surface features); 2) 4 posttreatment features reflecting the metal artifact profile of the various imaging modalities (visualization of clip or coil placement, perianeurysmal clip/coil anatomy, neck remnant, and white-collar sign); and 3) 2 dynamic features (blood flow pattern and aneurysm pulsation). Results Flat-panel volumetric CT provided better image resolution than MDCT and was comparable to traditional catheter angiography. The surface features of aneurysms were demonstrated with much higher resolution, detail, and clarity by fpVCT compared with MDCT and angiography. Flat-panel volumetric CT was inferior to both MDCT and angiography in terms of image noise and motion artifacts. In fpVCT images, the metallic artifacts from clips and coils were significantly fewer than those in MDCT images. As a result, clinically important information about posttreatment aneurysm neck remnants could be derived from fpVCT images but not from MDCT images. Time-resolved dynamic sequences were judged slightly inferior to conventional angiography but superior to static MDCT images. Conclusions The spatial resolution, surface anatomy visualization, metal artifact profile, and 4D dynamic images from fpVCT are superior to those from MDCT. Flat-panel volumetric CT demonstrates aneurysm surface features to better advantage than angiography and is comparable to angiography in metal artifact profile. Even though the temporal resolution of fpVCT is not quite as good as that of angiography, fpVCT images yield clinically important anatomical information about aneurysm surface features and posttreatment neck remnants not attainable with either angiography or MDCT images.

Intracranial dural arteriovenous fistulas (dAVFs) are commonly encountered in centers specializing in cerebrovascular diseases. Knowing the precise site of fistulous communication with the venous structures is essential in targeting the appropriate surgical or endovascular therapy once a decision to treat has been made. Such sites can usually be located with digital subtraction angiography alone. The authors describe a case in which localization was best performed using cone-beam volume CT in the angiography suite after selective microcatheterization of the feeding vessel and injection of a contrast agent in a dAVF related to the petrous temporal bone. Imaging studies showed the lesion was related to the inferior aspect of the tentorium, warranting a suboccipital surgical approach to treat the fistula.

✓ To the authors' knowledge, only 1 case of communicating hydrocephalus after endovascular coiling of unruptured brain aneurysms has been reported previously. Here, they report on 2 such cases of delayed communicating hydrocephalus after treatment with hydrogel-coated coils and offer the first histopathological evidence of foreign material, presumably related to the coils, as the cause of hydrocephalus.

✓ In this report, the authors present the case of a patient with a unique type of spinal arteriovenous fistula. Both the location and venous angioarchitecture of this variant are uncommon, making diagnosis of the lesion challenging and raising particular management issues. The authors discuss this unusual lesion and describe its imaging features and surgical findings, as well as highlight its pathological abnormalities.

A 51-year-old gentleman of Chinese descent presented for neurological evaluation following a two-year history of cervical neck pain associated with left arm numbness. His symptoms were initially stable, but had progressed over the past six months to include weakness of his entire left arm and leg and symptoms of bladder urgency. Two weeks prior to presentation, he suffered repeated falls due to worsening gait difficulties. The past medical history was significant for type II diabetes mellitus.

Purpose Timely recanalization during endovascular procedures for acute ischemic stroke can be challenging in cases with large clot burden as those encountered in the terminal internal carotid, T- or L-type occlusion. Methods A novel but simple technique to achieve fast reduction in clot burden in stroke patients with occlusion of the internal carotid artery termination is described where manual suction using a 60 ml syringe applied through an 8-French Balloon guide catheter positioned in the cervical carotid vasculature with proximal flow arrest allows subsequent revascularization of the residual middle cerebral artery clot. Results The use of manual suction through balloon-tipped guide catheter in ICA L- or T-type occlusion is illustrated. This resulted in significant reduction of the clot burden and facilitated further interventions leading to full recanalization. Conclusion Manual suction using 60 ml syringe through balloon guide catheter is a useful and feasible technique that facilitates thrombectomy of large burden cerebral clots. Competing interests None.

Some substantial number of unfortunate patients suffer from the symptoms and signs of elevated cerebrospinal fluid (CSF) pressure, even though pressure measured in the cerebral venous system is normal. We hypothesize that, with elevated CSF pressure, cerebral microvascular congestion may occur, even though (subdural) large-vein pressure has been shown to be normal.