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BackgroundRepeated number of passes, clot fragmentation, and distal embolization during mechanical thrombectomy (MT) lead to worse clinical outcomes in acute ischemic stroke. This study aimed to assess the recanalization and embolic outcomes of different stent-retrievers (SRs): open-tip SR (Solitaire X 6×40 mm), closed-tip SR (EmboTrap II 5×33 mm), and filter-tip SR (NeVa NET 5.5×37 mm).MethodsStiff-friable clot analogs were used to create middle cerebral artery (M1-MCA) occlusions in a benchtop model. After occlusion, experiments were randomized into one of the three treatment arms. The thrombectomy technique consisted of retrieving the SR into a balloon guide catheter under proximal flow arrest and continuous aspiration. A total of 150 single-attempt cases were performed (50 cases/treatment arm). Distal emboli (>100 µm) were collected and analyzed after each experiment.ResultsFilter-tip SR achieved a non-significantly higher first-pass recanalization rate than open-tip SR and closed-tip SR (66% vs 48% vs 44%; P=0.064). Filter-tip SR prevented clot fragments>1 mm from embolizing distal territories in 44% of cases, compared with 16% in open-tip SR and 20% in closed-tip (P=0.003). There were no significant differences between treatment arms in terms of total emboli count (open-tip=19.2±13.1, closed-tip=19.1±10.7, filter-tip=17.2±13.0; P=0.660). Nonetheless, the number of large emboli (>1 mm) and total area of emboli were significantly lower in the filter-tip arm (n=0.88±1.2, A=2.06±1.85 mm2) than in the closed-tip arm (n=2.34±3.38, A=4.06±4.80 mm2; PConclusionsWhen facing fragment-prone clots, the filter-tip SR significantly reduces the number of large clots (>1 mm) that embolize distally during an MT procedure, which in turn may increase the chances of first-pass complete recanalization.

Imbalance between positive and negative outcomes, a so-called class imbalance, is a problem generally found in medical data. Imbalanced data hinder the performance of conventional classification methods which aim to improve the overall accuracy of the model without accounting for uneven distribution of the classes. To rectify this, the data can be resampled by oversampling the positive (minority) class until the classes are approximately equally represented. After that, a prediction model such as gradient boosting algorithm can be fitted with greater confidence. This classification method allows for non-linear relationships and deep interactive effects while focusing on difficult areas by iterative shifting towards problematic observations. In this study, we demonstrate application of these methods to medical data and develop a practical framework for evaluation of features contributing into the probability of stroke.

Background Despite the proven benefit of transradial access over transfemoral access in cardiac procedures, the transition for cerebrovascular procedures has only been slowly enforced. We present our experience with transradial access in cerebral diagnostic angiographies and neurointerventional procedures. Methods We performed a retrospective analysis of patients who underwent transradial access for cerebrovascular procedures in 3 German centers between February 2017 and May 2019. Demographics, technical features, and complications were evaluated. Results Transradial access was successful in 40/45 endovascular procedures (89%). Selected catheterization of the intended vessels was obtained in 95% of cases (40/42). The rate of procedure-related vascular complications was 2% (1/45). Conclusions In this small retrospective series, transradial access proved to be safe and efficient. In the future, it is planned to further promote it as a standard access alternative for more patients.

BackgroundThe CLinical Assessment of WEB device in Ruptured aneurYSms (CLARYS) study has shown that the endovascular treatment of ruptured bifurcation aneurysms with the Woven EndoBridge (WEB) is safe and effective and provides protection against rebleeding at 1 month and 1 year. The 12-month angiographic follow-up is an important endpoint of the study.MethodsThe CLARYS study is a prospective multicenter study conducted in 13 European centers. The study enrolled 60 patients with 60 ruptured aneurysms of the anterior and posterior circulation. The study was conducted with an independent assessment of safety outcomes and imaging.ResultsSixty patients with 60 ruptured bifurcation aneurysms to be treated with the WEB were included. Fifty-three aneurysms (88.3%) had a broad base with a dome to neck ratio ConclusionsThe CLARYS study has previously shown that the use of the WEB in the endovascular treatment of ruptured bifurcation aneurysms provides effective protection against rebleeding with a good safety profile. The angiographic occlusion rates at 1 year reported here are comparable to those already seen in previous multicenter studies which primarily included unruptured aneurysms.

BackgroundThe primary goal of the CLARYS study is to assess the protection against rebleeding when treating ruptured bifurcation aneurysms with the Woven EndoBridge (WEB) device.MethodsThe CLARYS study is a prospective, multicenter study conducted in 13 European centers. Patients with ruptured bifurcation aneurysms were consecutively included between February 2016 and September 2017. The primary endpoint was defined as the rebleeding rate of the target aneurysm treated with the WEB within 30 days postprocedure. Secondary endpoints included periprocedural and postprocedural adverse events, total procedure and fluoroscopy times, and modified Rankin Scale score at 1 month and 1 year.ResultsSixty patients with 60 ruptured bifurcation aneurysms to be treated with the WEB were included. A WEB device was successfully implanted in 93.3%. The rebleeding rate at 1 month and 1 year was 0%. The mean fluoroscopy time was 27.0 min. Twenty-three periprocedural complications were observed in 18 patients and resolved without sequelae in 16 patients. Two of these complications were attributed to the procedure and/or the use of the WEB, leading to a procedure/device-related intraoperative complication rate of 3.3%. Overall mortality at 1 month and 1 year was 1.7% and 3.8%, respectively and overall morbidity at 1 month and 1 year was 15% and 9.6%, respectively. WEB-related 1-month and 1-year morbidity and mortality was 0%.ConclusionsThe interim results of CLARYS show that the endovascular treatment of ruptured bifurcation aneurysms with the WEB is safe and effective and, in particular, provides effective protection against rebleeding. It may induce profound change in the endovascular management of ruptured bifurcation aneurysms.

A neurointerventional training model called HANNES (Hamburg ANatomical NEurointerventional Simulator) has been developed to replace animal models in catheter-based aneurysm treatment training. A methodical approach to design for mass adaptation is applied so that patient-specific aneurysm models can be designed recurrently based on real patient data to be integrated into the training system.HANNES’ modular product structure designed for mass adaptation consists of predefined and individualized modules that can be combined for various training scenarios. Additively manufactured, individualized aneurysm models enable high reproducibility of real patient anatomies. Due to the implementation of a standardized individualization process, order-related adaptation can be realized for each new patient anatomy with modest effort. The paper proves how the application of design for mass adaptation leads to a well-designed modular product structure of the neurointerventional training model HANNES, which supports quality treatment and provides an animal-free and patient-specific training environment.

This is a report of the first three cases of endovascular aneurysm treatment that were proctored by a remote interventionalist using a novel high-resolution low-latency streaming technology. The proctor was located in a neurovascular centre and supported the treating interventional teams in two distant cities (up to 800 km/500 miles apart). All aneurysms were treated using the Woven EndoBridge (WEB) embolisation system, either electively or following subarachnoid haemorrhage. On-site proctoring was not possible due to travel restrictions during the COVID-19 pandemic. WEB placement was feasible in all cases. Good rapport between proctors and treating physicians was reported, enabled by the high-resolution image transmission and uninterrupted feedback/discussion via audiostream. No clinical complications were encountered. Short-term follow-up revealed adequate occlusion of all treated aneurysms. The employed streaming technology provided effective remote proctoring during complex aneurysm cases, including the management of technical complications.

For testing new designs of braided stents, an animal free anatomical model is needed, in which different Flow Diverter (FD) designs can be implanted and evaluated. The geometric replication of vessels by additively manufactured (AM) models has already been proven for aneurysm coiling within the neurointerventional training model HANNES. Nevertheless, since FDs closely interact with the vessel wall, AM vessel model materials need to be qualificated for the use case. Therefore, this paper presents an appropriate test bench for AM material tests and characterizes AM impact factors. As an outlook, different AM materials are tested and compared. Additionally, the impact of the postprocessing is investigated for one material.

Congenital bilateral perisylvian syndrome (CBPS) is a rare neurological disorder associated with typical clinical and imaging features such as bilateral symmetrical polymicrogyria, either exclusively or mainly affecting the perisylvian region of the brain. We present a girl with the typical clinical picture of a CBPS and a complex migration disorder, predominantly presenting as bilateral symmetrical polymicrogyria associated with corpus callosum hyperplasia, ventricular dilation, and pontine hypoplasia. At the age of 6 months, the girl showed a profound global developmental delay, seizures refractory to treatment, and severe oromotor dysfunction. Exome analysis revealed a de novo mutation in microtubule-associated serine/threonine kinase 1 (MAST1). Recently, mutations in this gene were described in six patients with a cortical migration disorder named mega-corpus-callosum syndrome with cerebellar hypoplasia. Although all patients present the clinical and imaging features of CBPS, a clear assignment between CBPS and MAST1 mutations has not been reported yet.

ObjectiveTo meet increasing demands to train neuroendovascular techniques, we developed a dedicated simulator applying individualized three-dimensional intracranial aneurysm models ('HANNES'; Hamburg Anatomic Neurointerventional Endovascular Simulator). We hypothesized that HANNES provides a realistic and reproducible training environment to practice coil embolization and to exemplify disparities between neurointerventionalists, thus objectively benchmarking operators at different levels of experience.MethodsSix physicians with different degrees of neurointerventional procedural experience were recruited into a standardized training protocol comprising catheterization of two internal carotid artery (ICA) aneurysms and one basilar tip aneurysm, followed by introduction of one framing coil into each aneurysm and finally complete coil embolization of one determined ICA aneurysm. The level of difficulty increased with every aneurysm. Fluoroscopy was recorded and assessed for procedural characteristics and adverse events.ResultsPhysicians were divided into inexperienced and experienced operators, depending on their experience with microcatheter handling. Mean overall catheterization times increased with difficulty of the aneurysm model. Inexperienced operators showed longer catheterization times (median; IQR: 47; 30-84s) than experienced operators (21; 13-58s, p = 0.011) and became significantly faster during the course of the attempts (rho = -0.493, p = 0.009) than the experienced physicians (rho = -0.318, p = 0.106). Number of dangerous maneuvers throughout all attempts was significantly higher for inexperienced operators (median; IQR: 1.0; 0.0-1.5) as compared to experienced operators (0.0; 0.0-1.0, p = 0.014).ConclusionHANNES represents a modular neurointerventional training environment for practicing aneurysm coil embolization in vitro. Objective procedural metrics correlate with operator experience, suggesting that the system could be useful for assessing operator proficiency.

Background: In large vessel occlusion stroke, intracranial navigation of large-bore aspiration catheters can be impeded by vessel curvature and ophthalmic artery origin. Novel conically-shaped delivery assist devices are designed to facilitate delivery. We assessed aspiration catheter deliverability in several patient-specific in vitro models. Methods: In a flow model replicating vascular access from the femoral to the middle cerebral artery, two different commercially available aspiration catheters were repeatedly advanced through a commercial 0.088” sheath from the carotid bifurcation to the middle cerebral artery by five neurointerventionalists under fluoroscopy. Three craniocervical access scenarios were manufactured based on challenging patient anatomy. Catheter deliverability was assessed with standard microwire/microcatheter combinations (MC) and the Tenzing™ 7 catheter (T7). Procedural characteristics were recorded, and operators rated carotid artery deflection, guide catheter pushback and difficulty passing the ophthalmic artery origin on a 5-point scale (1=none, 5=most severe). Results: Among 117 delivery attempts, the target vessel was reached significantly more often with T7 (96%) than with MC (66%, p Conclusion: Compared to microcatheter & microwire combinations, the T7 delivery assist catheter significantly facilitates aspiration catheter delivery to the target vessel in vitro.

To compare the learning benefit of three different teaching strategies on the interpretation of emergency cerebral computed tomography (CT) pathologies by medical students. Three groups of students with different types of teaching (e-learning, interactive teaching, and standard curricular education in neuroradiology) were tested with respect to the detection of seven CT pathologies. The test results of each group were compared for each CT pathology using the chi-square test. A p-value ≤ 0.05 was considered to be significant. Opposed to the results of the comparison group (curricular education), the e-learning group and interactive teaching tutorial group both showed a significantly better performance in detecting hyperdense middle cerebral artery sign (p = 0.001 and p 0.0001) as well as subarachnoid hemorrhage (p = 0.03 and p = 0.001) on CT. Moreover, an increase in performance for the detection of subdural hematoma and skull fracture could be observed for both the interactive teaching group and the e-learning group, with statistical significance in the latter (p = 0.03 and p 0.0001, respectively). No statistically significant differences were found for the detection of intracranial and epidural hemorrhage, as well as midline shift, among the groups studied. Our study demonstrates potential learning benefits for both the interactive teaching tutorial and e-learning module group with respect to reading CT scans with slightly different advantages. Thus, the introduction of new learning methods in radiological education might be reasonable at an undergraduate stage but requires learning content-based considerations. · E-learning can offer benefits regarding the reading of cerebral CT scans by students. · Interactive tutorial can offer benefits regarding the reading of cerebral CT scans by students. · E-learning and interactive tutorial feature different strengths for student learning in radiology. · Application of interactive teaching methods in radiology requires learning content-based considerations.· Groth M, Barthe KG, Riemer M et al. Critical Analysis of an e-Learning and Interactive Teaching Module with Respect to the Interpretation of Emergency Computed Tomography of the Brain. Fortschr Röntgenstr 2017; 190: 334 - 340.ZIEL: Vergleich von drei verschiedenen Lehrmethoden zur Interpretation von Notfall-Pathologien mit der zerebralen Computertomografie (CT) durch Medizinstudenten. Drei Studentengruppen wurden bzgl. der Detektion von sieben CT-Pathologien getestet, nachdem sie verschiedene Lehrmethoden absolviert hatten (e-Learning, interaktives Seminar, curriculäre Lehre). Die Testergebnisse der drei Gruppen wurde für jede Pathologie mit einem Chi-Quadrat-Test verglichen. Das Signifikanzniveau wurde ≤ 0,05 gewählt. Im Gegensatz zur Vergleichsgruppe (curriculäre Lehre) zeigten die e-Learning- und Interaktivseminar-Gruppe signifikant bessere Ergebnisse bei der Detektion des „hyperdensen Mediazeichens“ (p = 0,001 und p 0,0001) sowie der Subarachnoidalblutung (p = 0,03 und p = 0,001). Darüber hinaus zeigten sowohl die Interaktivseminar- als auch die e-Learning-Gruppe bessere Ergebnisse für die Detektion eines subduralen Hämatoms und einer Kalottenfraktur, wobei nur die letzte Gruppe hier eine statistische Signifikanz aufwies (p = 0,03 und p 0,0001). Keine signifikanten Unterschiede zeigten sich für Pathologien wie intrakranielle Blutung, epidurales Hämatom und Mittellinienverlagerung. Unsere Studie zeigt jeweils unterschiedliche potentielle Vorteile der Interaktivseminar- sowie der e-Learning-Gruppe bei der Interpretation von CTs. Daher können interaktive Lehrmethoden das Potenzial besitzen, die studentisch-radiologische Ausbildung zu verbessern, die passende Lehrform muss jedoch dem jeweiligen Lerninhalt angepasst werden. · E-Learning kann die studentische Beurteilungfähigkeit zerebraler CTs verbessern. · Ein interaktives Seminar kann die studentische Beurteilungfähigkeit zerebraler CTs verbessern. · E-Learning und Interaktivseminare besitzen unterschiedliche Stärken in der studentischen Radiologieausbildung. · Die Anwendung neuer Lehrmethoden in der Radiologie erfordert eine Lerninhalt spezifisch Anpassung.

Stroke patients are excluded from expeditious thrombectomy in regions lacking neurointerventional specialists. An audiovisual online streaming system was tested, allowing a neurointerventional specialist located at a neurovascular center to supervise and instruct a thrombectomy performed at a distant hospital without being physically present (remote streaming support [RESS]). In total, 36 thrombectomy procedures were performed on a Mentice endovascular simulator by six radiologists not specialized in neurointerventions. Each radiologist was challenged with six different endovascular simulation scenarios under alternating conventional local support (specialist inside the room [LOS]) and RESS, which was performed using an advanced live streaming platform. Both support modes led to a median of 2 attempts (interquartile range [IQR] 2.0–2.0 each) until successful recanalization. There was no statistically significant difference in time from first catheter insertion to recanalization between LOS (median 24.9 min, IQR 21.0–31.5 min) and RESS (23.9 min, IQR 21.7–28.7 min, p = 0.89). The percentage of thrombi covered by the stent-retriever and average speed when retrieving the stent-retriever (3.7 mm/s, IQR 3.25–5.35 mm/s vs. 3.6 mm/sec, IQR 2.5–4.7) were similar in both groups. Fluoroscopy time did not differ (19.0 min, IQR 16.9–23.5 min vs. 19.9 min, IQR 15.9–23.5 min) with a trend towards increased median amounts of contrast medium used under RESS (62.9 ml vs. 43.1 ml; p = 0.055). This study confirmed the feasibility of RESS for thrombectomy procedures in a simulated environment. This serves as basis for future studies planned to analyze the effectiveness of RESS in a real-world environment and to test if it improves the learning curve of interventionalists with limited thrombectomy experience in remote areas.

Atrial fibrillation (AF) is the most common irregular heartbeat among the world's population and is a major contributor to cardiogenic embolisms and acute ischemic stroke (AIS). However, the role AF flow plays in the trajectory paths of cardiogenic emboli has not been experimentally investigated. A physiological simulation system was designed to analyze the trajectory patterns of bovine embolus analogs (EAs) (n = 720) through four patient-specific models, under three flow conditions: steady flow, normal pulsatile flow, and AF pulsatile flow. It was seen that EA trajectory paths were proportional to the percentage flowrate split of 25–31% along the branching vessels. Overall, AF flow conditions increased trajectories through the left- (LCCA) and right (RCCA)-common carotid artery by 25% with respect to normal pulsatile flow. There was no statistical difference in the distribution of clot trajectories when the clot was released from the right, left, or anterior positions. Significantly, more EAs traveled through the brachiocephalic trunk (BCT) than through the LCCA or the left subclavian. Yet of the EAs that traveled through the common carotid arteries, there was a greater affiliation toward the LCCA compared to the RCCA (p

BACKGROUND AND PURPOSE: Flow disruption with the Woven EndoBridge (WEB) device is an innovative technique for the endovascular treatment of wide-neck bifurcation aneurysms. The initial version of the device (WEB Double-Layer) was evaluated in the WEB Clinical Assessment of IntraSaccular Aneurysm Therapy (WEBCAST) study, whereas the French Observatory study evaluated both WEB Double-Layer and Single-Layer versions of the device. WEBCAST 2 was designed to evaluate the WEB Single-Layer with Enhanced Visualization. MATERIALS AND METHODS: Patients with wide-neck bifurcation aneurysms for which WEB treatment was possible were included. Clinical data including adverse events and clinical status at 1 month and 1 year were collected and analyzed. A core laboratory evaluated anatomic results at 1 year following the procedure. RESULTS: Ten European neurointerventional centers included 55 patients (38 women; 27–77 years of age; mean, 54.4 ± 10.0 years) with 55 aneurysms. Aneurysm locations were the middle cerebral artery in 25 aneurysms (45.5%), the anterior communicating artery in 16 (29.1%), the basilar artery in 9 (16.4%), and the internal carotid artery terminus in 5 (9.1%). Procedural morbidity and mortality at 1 month were, respectively, 1.8% (1/55 patients) and 0.0% (0/55 patients). Morbidity and mortality at 1 year were, respectively, 3.9% (2/51 patients) and 2.0% (1/51 patients). At 1 year, complete occlusion was observed in 27/50 aneurysms (54.0%); neck remnant, in 13/50 (26.0%); and aneurysm remnant, in 10/50 (20.0%) (adequate occlusion in 40/50, 80.0%). CONCLUSIONS: WEBCAST 2 confirms the high safety and efficacy of WEB aneurysm treatment demonstrated in the WEBCAST and French Observatory studies.

The purpose of this paper is the investigation of automatic evaluation of the quality of patient positioning and Field of View (FoV) in head CT scans. Studies have shown elevated risk of radiation-induced cataract in patients undergoing head CT examinations. The American Association of Physicists in Medicine (AAPM) published a protocol for head CT scans including requirements linking the optimal scan angle to anatomic landmarks in the skull. To help sensitizing staff for the need of correct patient positioning, a software-based tool detecting nonoptimal patient positioning was developed. Our experiments were conducted on 209 head CT exams acquired at the University Medical Center Hamburg Eppendorf (UKE). All of these examinations were done on the same Philips iCT scanner. Each exam contains a 3D volume with an in-plane voxel spacing of 0.44mm x 0.44mm and a slice distance of 1mm. As ground truth anatomic landmarks on the skull were annotated independently by three different readers. We applied an atlas registration technique to map CT scans to a probabilistic anatomical atlas. For a new CT scan, previously defined model landmarks were mapped back to the CT volume when registering it to the atlas thus labelling new head CT scans. From the location of the detected landmarks we derive the deviation of the actual head angulation and scan length from the optimal values. Furthermore, the presence of the eye-lenses in the FoV is predicted. The median error of the estimated landmark positions measured as distance to the plane generated from the ground truth landmark positions is below 1mm and comparable to the interobserver variability. A classifier for the prediction of the presence of the eye-lenses in the FoV from the estimated landmark locations achieves a κ value of 0.74. Furthermore there is moderate agreement of the estimated deviations of optimal head tilt and scan length with an expert’s rating.

The presence of intraparenchymal hyperattenuations (IPH) on flat-panel computed tomography (FP-CT) after endovascular recanalization in stroke patients is a common phenomenon. They are thought to occur in ischemic areas with breakdown of the blood-brain barrier but previous studies that investigated a mutual interaction are scarce. We aimed to assess the relationship of IPH localization with prethrombectomy diffusion-weighted imaging (DWI) lesions. This retrospective multicenter study included 27 acute stroke patients who underwent DWI prior to FP-CT following mechanical thrombectomy. After software-based coregistration of DWI and FP-CT, lesion volumetry was conducted and overlapping was analyzed. Two different patterns were observed: IPH corresponding to the DWI lesion and IPH exceeding the DWI lesion. The latter showed demarcated infarction of DWI exceeding IPH at 24 h. No major hemorrhage following IPH was observed. Most IPH were manifested within the basal ganglia and insular cortex. The IPH primarily appeared within the initial ischemic core and secondarily within the penumbral tissue that progressed to infarction. The IPH represent the minimum final infarct volume, which may help in periinterventional decision making.

Background and purposeEvidence on how to select microcatheters to facilitate aneurysm catheterization during coil embolization is sparse. We developed a new method to define microcatheter tip location inside a patient-specific aneurysm model as a 3-dimensional probability map. We hypothesized that precision and accuracy of microcatheter tip positioning depend on catheter tip shape and aneurysmal geometry.Materials and methodsUnder fluoroscopic guidance two to three operators introduced differently shaped microcatheters (straight, 45°, 90°) into eight aneurysm models targeting the anatomic center of the aneurysm. Each microcatheter position was recorded with flat-panel CT, and 3-dimensional probability maps of the microcatheter tip positions were generated. Maps were assessed with histogram analyses and compared between tip shapes, aneurysm locations and operators.ResultsAmong a total of 530 microcatheter insertions, the precision (mean distance between catheter positions) and accuracy (mean distance to target position) were significantly higher for the 45° tip (1.10±0.64 mm, 3.81±1.41 mm, respectively) than for the 90° tip (1.27±0.57 mm, p=0.010; 4.21±1.60 mm p=0.014, respectively). Accuracy was significantly higher in posterior communicating artery aneurysms (3.38±1.20 mm) than in aneurysms of the internal carotid artery (4.56±1.54 mm, pConclusionOur method can be used tostatistically describe statistically microcatheter behavior in patient-specific anatomy, which may improve the available evidence guiding microcatheter shape selection. Experience increases the ability to reach the intended position with a microcatheter (accuracy) that is also dependent on the aneurysm location, whereas catheter tip choice determines the variability of catheter tip placements versus each other (precision). Clinical validation is required.

Introduction The intrasaccular flow diversion device WEB is a system used in the treatment of wide necked bifurcation aneurysm. The large number of clinical studies conducted have included mainly unruptured aneurysms. The CLARYS study has been set up to evaluate the efficacy and the safety of the WEB system used to treat bifurcation ruptured aneurysms. Materials and methods The CLARYS study is a prospective, multicenter evaluation conducted in 13 interventional neuroradiological departments in France and Germany. The study design meets the Good Clinical Practice (GCP) standards with data collected in an eDC 100% monitored and endpoints independently evaluated. The primary endpoint is defined as the re-bleeding rate at 1 month post procedure. The secondary endpoints are the rate of adverse events related to the device, the procedure or the disease, the neurological evaluation at 1 month and 1 year based on mRS, the occlusion at 1 year based on the WEB Occlusion Scale (WOS) and the procedure and fluoroscopy time. Results From February 2016 to September 2017, 60 patients (women: 31, 51.7%; mean age: 54.5±1.49 years) with 60 aneurysms were included in the study. The aneurysms locations were at the anterior communicating artery (26/60, 43.3%), the middle cerebral artery bifurcation (23/60, 38.3%), the basilar apex (7/60, 11.7%), the anterior cerebral artery (2/60, 3.3%), the internal carotid artery terminus (1/60, 1.7%) and the posterior communicating artery (1/60, 1.7%). The WEB device was successfully implanted in 56/60 cases (95.0%) The adverse events reported by the sites and adjudicated by the Clinical Event Adjudicator (CEA) were described based on timeline occurrence (per procedure or post procedure), category of events, clinical impact and relationship to device, procedure or disease. The primary endpoint will be presented as well as the morbidity and mortality at 1 month. The 12 months data are under collection so will not be available. Conclusion The study results at 1 month will be presented to address the rate of re bleeding and the safety of the device used in the treatment of ruptured bifurcation aneurysm, following clinical evaluation conducted according to study GCP. Disclosures D. Herbreteau: 2; C; MicroVention. A. Narata: None. R. Bibi: None. L. Ikka: None. C. Mihalea: None. J. Caroff: None. J. Moret: 2; C; MicroVention, Medtronic, Balt. 4; C; Sensome. X. Barreau: None. J. Ferre: None. J. Gauvrit: None. H. Raoult: None. J. Fiehler: 1; C; German Ministry of Science and Education (BMBF), German Ministry of Economy and Innovation (BMWi), German Research Foundation (DFG), European Union (EU), Hamburgische Investitions-und Forderbank (IFB), Medtronic, MicroVention, Philips, Stryker. 2; C; Acandis, Boehringer Ingelheim, Cerenovus, Covidien, Medtronic, Medina, MicroVention, Penumbra, Route 92, Stryker. J. Buhk: 2; C; Sequent, MicroVention. V. Costalat: 2; C; Medtronic, Stryker, Balt, Cerenovus, MicroVention. A. Januel: None. C. Cognard: 2; C; Stryker, MicroVention, Medtronic, Cerenovus. T. Liebig:None. M. Bester: None. H. Desal: None. B. Daumas-Duport: None. R. Bourcier: None. M. Mohlenbruch: None. J. Berkefeld: 2; C; Sequent/MicroVention. R. Du Mesnil de Rochemont: 2; C; Sequent. W. Weber: 2; C; Phenox, MicroVention, Medtronic, Penumbra, Stryker. S. Velasco:None. A. Biondi: None. J. Byrne: 2; C; Oxford Endovascular Ltd. L. Pierot: 2; C; Balt, Cerus Endovascular, MicroVention/Sequent, Phenox, Vesalio, Penumbra.

Background Flow diversion has become an accepted endovascular treatment modality for intracranial aneurysms. Studies comparing different types of flow diverters are currently lacking. Objective To perform a propensity score-matched cohort study comparing the Pipeline Embolization Device (PED; Medtronic, Dublin, Ireland) and Flow Redirection Endoluminal Device (FRED; MicroVention, Aliso Viejo, California). Methods Aneurysms of the internal carotid artery proximal to the communicating segment treated with PED at 2 neurovascular centers in the United States were matched with aneurysms treated in the European FRED study using propensity scoring. Aneurysms treated in the setting of subarachnoid hemorrhage were excluded from matching. Occlusion rates and complications were evaluated. Results Two hundred twenty-one internal carotid artery aneurysms were treated with PED and 282 with FRED. Propensity score matching controlling for age, sex, aneurysm size, location, number of flow diverters, and adjunctive coiling resulted in 55 matched pairs. Median angiographic follow-up was nonsignificantly longer for FRED compared to PED (12.2 vs 7.5 mo, P = .28). The rate of complete occlusion did not differ between flow diverters (80% vs 80%, P > .99). Functional outcome and complications were comparable for PED and FRED. Conclusion Propensity score-matched analysis of PED and FRED for internal carotid artery aneurysms revealed comparable angiographic complete occlusion and complication rates. Whether FRED has an advantage in terms of near complete aneurysm occlusion warrants further investigation. Limitations include the retrospective design and lack of an independent assessment of radiographic outcome in a core-laboratory and functional outcomes, among others, and the results should be interpreted as such.

PurposeMechanical thrombectomy (MT) is a highly effective therapy in patients with acute ischemic stroke due to large vessel occlusion (LVO). However, complete recanalization of the occluded vessel cannot be achieved in all patients, leading to poor clinical outcome. We analyzed the reasons for failed recanalization to help direct future improvements in therapy.Methods648 consecutive stroke patients with LVO and an MT attempt were retrospectively analyzed for none or minimal recanalization, assessed according to the Thrombolysis in Cerebral Infarction (TICI) score (0/1). Procedural parameters were evaluated in a standardized approach. Among other variables, number of retrieval attempts, devices, duration of the intervention, and rescue methods were analyzed.ResultsTICI 0/1 was observed in 72/648 patients (11%). In these patients, the thrombus could not be reached in 21% (n=15/72), was reached but not passed in 21% (n=15/72), and was reached and passed in 58% (n=42/72). Only a minor degree of initial recanalization was achieved in 19% (n=8/42) of patients with a reached occlusion during the course of the intervention. Furthermore, a higher number of passes with a single retriever device led to significant prolongation of the intervention. Therefore, major reasons for failed endovascular recanalization were difficult anatomical access and hard or resistant occlusions that might reflect hard thrombi or pre-existing atherosclerotic stenosis. Procedural complications such as dissection or perforation played a minor role.ConclusionIn stroke patients with failed MT attempts, approximately 60% of occlusions can be passed. In such cases, rescue therapy might be considered to improve recanalization and clinical outcome. Further development of access devices might help in the remaining cases where the microcatheter could not be manipulated to or through the occlusion.

BACKGROUND AND PURPOSE: Angiographic occlusion and retreatment of coiled aneurysms are commonly used as surrogate end points in clinical trials. We aimed to evaluate the influence of aneurysm, patient, and rater characteristics on the confidence of visual evaluation of aneurysm coiling and retreatment decisions. MATERIALS AND METHODS: Twenty-six participants of the Advanced Course in Endovascular Interventional Neuroradiology of the European Society of Neuroradiology were asked to evaluate digital subtraction angiography examinations of patients who had undergone endovascular coiling, by determining the grade of aneurysm occlusion, the change between immediate postprocedural and follow-up angiograms, their level of confidence, the technical difficulty of retreatment, and the best therapeutic approach. The experience, knowledge, and skills of each participant were assessed. The influence of rater and case characteristics on indicated confidence in diagnostic ratings and retreatment recommendations was analyzed. RESULTS: Interrater reliability was moderate regarding the assessment of aneurysm occlusion grade (intraclass correlation coefficient = 0.581) and substantial regarding change (intraclass correlation coefficient = 0.776). Overall confidence in the diagnostic rating was high (median, “very certain”). Confidence was statistically significantly higher in cases that were generally rated as “worse.” The odds of recommending retreatment were significantly higher in cases that were generally rated with higher mean confidence. CONCLUSIONS: Although overall confidence in the diagnostic rating was high, our study confirms the suboptimal interrater reliability of visual assessment of aneurysm occlusion as well as retreatment recommendations, rendering both questionable as primary outcome measures. Besides recurrence status, recommendation of retreatment is significantly influenced by patient age, aneurysm neck width, and characteristics of the therapist.

PurposeSeveral different training environments for practicing neurointerventional procedures have been realized in silico, in vitro, and in vivo. We seek to replace animal-based training with suitable alternatives. In an effort to determine present training model distribution and preferences, we interviewed interventional neuroradiologists from 25 different countries about their experience in distinct training environments.MethodsA voluntary online survey comprising 24 questions concerning the different training facilities was designed and electronically conducted with the members of the European Society for Minimally Invasive Neurological Therapy.ResultsSeventy-one physicians with an average experience of 11.8 (±8.7) years completed the survey. The majority of participants had experience with animal-based training (eg, stroke intervention: 36; 50.7%). Overall, animal-based training was rated as the most suitable environment to practice coil embolization (20 (±6)), flow diverter placement (13 (±7)), and stroke intervention (13.5 (±9)). In-vitro training before using a new device in patients was supported by most participants (35; 49.3%). Additionally, preference for certain training models was related to the years of experience.ConclusionThis survey discloses the preferred training modalities in European neurointerventional centers with the majority of physicians supporting the general concept of in-vitro training, concomitantly lacking a standardized curriculum for educating neurointerventional physicians. Most suitable training modalities appeared to be dependent on procedure and experience. As animal-based training is still common, alternate artificial environments meeting these demands must be further developed.

BACKGROUND AND PURPOSE: Endoluminal reconstruction with flow-diverting stents represents a widely accepted technique for the treatment of complex intracranial aneurysms. This European registry study analyzed the initial experience of 15 neurovascular centers with the Flow-Redirection Intraluminal Device (FRED) system. MATERIALS AND METHODS: Consecutive patients with intracranial aneurysms treated with the FRED between February 2012 and March 2015 were retrospectively reviewed. Complications and adverse events, transient and permanent morbidity, mortality, and occlusion rates were evaluated. RESULTS: During the defined study period, 579 aneurysms in 531 patients (median age, 54 years; range, 13–86 years) were treated with the FRED. Seven percent of patients were treated in the acute phase (≤3 days) of aneurysm rupture. The median aneurysm size was 7.6 mm (range, 1–36.6 mm), and the median neck size 4.5 mm (range, 1–30 mm). Angiographic follow-up of >3 months was available for 516 (89.1%) aneurysms. There was progressive occlusion witnessed with time, with complete occlusion in 18 (20%) aneurysms followed for up to 90 ± 14 days, 141 (82.5%) for 180 ± 20 days, 116 (91.3%) for 1 year ± 24 days, and 122 (95.3%) aneurysms followed for >1 year. Transient and permanent morbidity occurred in 3.2% and 0.8% of procedures, respectively. The overall mortality rate was 1.5%. CONCLUSIONS: This retrospective study in real-world patients demonstrated the safety and efficacy of the FRED for the treatment of intracranial aneurysms. In most cases, treatment with a single FRED resulted in complete angiographic occlusion at 1 year.

ObjectiveTo evaluate multiparametric MRI including non-contrast and contrast-enhanced morphological and angiographic techniques for intracranial aneurysms treated with the single-layer Woven EndoBridge (WEB) embolization system applying simultaneous digital subtraction angiography (DSA) as the reference of standard.Materials and methodsWe retrospectively identified all patients with incidental and acute ruptured intracranial aneurysms treated with a WEB device (WEB SL and WEB SLS) between March 2014 and June 2016 in our neurovascular center with early (within 7 days) postinterventional multiparametric MRI as well as mid-term (5–8 months) follow-up MRI and DSA available. Occlusion rates were recorded both in DSA and MR angiography (MRA). In MRI, signal intensities within the WEB as well as in the occluded dome distal to the WEB, if present, were measured by region-of-interest (ROI) analysis.ResultsTwenty-five patients fulfilled the inclusion criteria. Rates of complete/adequate occlusion at mid-term follow-up were 84% with both MRA and DSA. A strong signal loss within the WEB was observed in all MR sequences at initial and follow-up examinations. ROI analysis did not reveal significant differences in non-contrast (P=0.946) and contrast-enhanced imaging (P=0.377). A T1-hyperintense thrombus in the non-WEB-carrying dome was a frequent observation.ConclusionsSignal intensity measurements in multiparametric MRI suggest that neither contrast-enhanced MRA nor morphological sequences are capable of revealing reliable information on the WEB lumen, presumably due to radio frequency shielding. MRI is therefore not suitable for confirming complete thrombus formation within the WEB.

Early, prehospital cooling seeks to reduce and control the body temperature as early as possible to protect the brain and improve patient outcome in cardiac arrest, stroke, and traumatic brain injury. In this study, we investigate the feasibility of localized cooling of the porcine brain by using a novel high-flow cold air protocol, which utilizes the close proximity between the nasal cavity and the brain. Five adult pigs were anesthetized and temperature change was mapped before, during, and after cooling by using the proton resonance frequency method on a 3 T Siemens Magnetom Skyra system. Cooling was performed by inserting a tube blowing high-flow (250 L/min) cold air (-10°C) through the nasal cavity for 5-20 minutes. The brain temperature change was measured by using an MRI phase mapping technique utilizing the temperature-dependent proton resonance frequency change. MRI maps showed significant temperature reduction of the porcine brain. On average, a mean whole-brain cooling effect of -0.33°C ± 0.30°C was found after 5 minutes of cooling. The anterior part of the brain was directly exposed to the cold and showed a significantly larger temperature drop (-0.83°C ± 0.51°C) than the posterior part (-0.03°C ± 0.21°C). However, a large variability of the temperature drop was observed between the animals. This variability may be caused by not well-controlled factors confounding the MRI temperature mapping, for example, subject movement, or cooling effectiveness, for example, core temperature or nasal patency. The results indicate that the proposed high-flow cold air protocol allows for localized cooling of the frontal porcine brain, which may be clinically relevant for traumatic injuries of the frontal brain where systemic cooling is unfavorable.

Maternal aneurysmal subarachnoid hemorrhage (aSAH) during pregnancy presents a challenge regarding treatment and management. Due to the limited number of cases there are no treatment guidelines available. Thus, treatment is usually done on a case-by-case basis. Here we report on four cases of aSAH during pregnancy, describing the different management strategies and suggesting a possible treatment algorithm. Patients treated between 2003 and 2013 in our center were included in this retrospective study. Clinical data focused on time management concerning gestation week (GW), microsurgical or endovascular treatment, and outcome of the patients and the fetuses. Results were compared to the present literature on this issue. Mean age was 30.8 years, initial HuntHess (HH) grade ranged from III to V. All patients suffered from aSAH during the 3rd trimester of pregnancy. In the four cases, two emergency Caesarean sections (CS) were performed. Two aneurysms were occluded by microsurgical clipping and one was treated endovascularly. One patient died before definitive treatment of the aneurysm could be achieved, whereas fetal mortality was 0%. The mean follow-up was 83 months. aSAH during pregnancy needs individualized interdisciplinary management. Efforts must focus on the mother so that a delay in the best available treatment for the pregnant patient is avoided. Therefore treatment modality should be primarily determined by the aneurysm itself. However, timing in terms of delivery of the fetus and aneurysm treatment is a crucial point.Die maternale aneurysmatische Subarachnoidalblutung (aSAB) während der Schwangerschaft bedeutet eine besondere Herausforderung hinsichtlich Behandlung und zeitlichen Managements. Aufgrund geringer Fallzahlen in der Literatur existieren keine standardisierten Behandlungsrichtlinien. Anhand von 4 Patientenfällen und der Darlegung der verschiedenen Behandlungsstrategien möchten wir einen neuen Algorithmus zur Behandlung schwangerer Patienten mit aSAB vorstellen. Es wurden Daten zwischen den Jahren 2003 und 2013 erhoben und hinsichtlich des zeitlichen Managements bezüglich Diagnostik und Therapie in Abhängigkeit von der Schwangerschaftswoche restropektiv analysiert. Die Art der Aneurysma-Behandlung, das Outcome der Patientinnen und der Neugeborenen wurde ausgewertet und mit der aktuellen Literatur verglichen. Das mittlere Alter lag bei 30,8 Jahren, der initiale HuntHess Grad reichte von III bis V. Alle Schwangerschaften befanden sich im 3. Trimenon. Es erfolgten 2 notfallmäßige Kaiserschnitte. In 2 Fällen erfolgte ein mikrochirurgisches Clipping, eine Patientin wurde endovaskulär versorgt und eine verstarb vor der endgültigen Aneurysmaversorgung. Die fetale Mortalität lag bei 0%. Die Subarachnoidalblutung während der Schwangerschaft bedarf eines interdisziplinären und individualisierten Therapiemanagements. Die therapeutischen Anstrengungen müssen die Mutter als Patientin im Fokus haben und jede Verzögerung in Diagnostik und Therapie unbedingt vermeiden. Das zeitliche Management einer eventuell notwendigen verfrühten Geburt im Hinblick auf die Aneurysmaversorgung spielt hierbei eine wesentliche Rolle.

Background and purposeThrombectomy has become the standard of care for acute ischaemic stroke due to large vessel occlusion. Aim of this study was to compare the radiological outcomes and time metrics of the various thrombectomy techniques.MethodsIn this retrospective, multicenter study we analysed the data of 450 patients with occlusion of the anterior circulation, treated in five high-volume center from 2013 to 2016. The treatment techniques were divided in three categories: first-pass use of a large-bore aspiration-catheter; first-pass use of a stent-retriever; and primary combined approach (PCA) of an aspiration-catheter and stent-retriever. Primary endpoints were successful reperfusion and groin to reperfusion time. Secondary endpoints were the number of attempts and occurrence of emboli in new territory (ENT). The primary analysis was based on the intention to treat groups (ITT).ResultsThe ITT-analysis showed significantly higher reperfusion rates, with 86% of successful reperfusion in the PCA-group compared with 73% in the aspiration group and 65% in the stent-retriever group. There was no significant difference in groin to reperfusion time regarding the used technique. The secondary analysis showed an impact of the technique on the number of attempts and the occurrence of ENTs. Lowest ENT rates and attempts were reported with the combined approach.ConclusionsThe combined first-pass deployment of a stent-retriever and an aspiration-catheter was the most effective technique for reperfusion of anterior circulation large vessel occlusion. Our results correlate with the latest single-centrere studies, reporting very high reperfusion rates with PCA variations.

Purpose Multidetector CT (MDCT) is the established imaging modality in diagnostics of urolithiasis. The aim of iterative reconstruction (IR) is to allow for a radiation dose reduction while maintaining high image quality. This study evaluates its performance in MDCT for assessment of urolithiasis. Materials and Methods Fifty-two patients underwent non-contrast abdominal MDCT. Twenty-six patients were referred to MDCT under suspicion of urolithiasis, and examined using a dose-reduced scan protocol (RDCT). Twenty-six patients, who had undergone standard-dose MDCT, served as reference for radiation dose comparison. RDCT images were reconstructed using an IR system (iDose4™, Philips Healthcare, Cleveland, OH, USA). Objective image noise (OIN) was recorded and five radiologists rated the subjective image quality independently. Radiation parameters were derived from the scan protocols. Results The CTDIvol could be reduced by 50% to 5.8 mGy (P

Purpose: To determine the image quality of an iterative reconstruction (IR) technique in low-dose MDCT (LDCT) of the chest of immunocompromised patients in an intraindividual comparison to filtered back projection (FBP) and to evaluate the dose reduction capability. Materials and Methods: 30 chest LDCT scans were performed in immunocompromised patients (Brilliance iCT; 20 – 40 mAs; mean CTDIvol: 1.7 mGy). The raw data were reconstructed using FBP and the IR technique (iDose4™, Philips, Best, The Netherlands) set to seven iteration levels. 30 routine-dose MDCT (RDCT) reconstructed with FBP served as controls (mean exposure: 116 mAs; mean CDTIvol: 7.6 mGy). Three blinded radiologists scored subjective image quality and lesion conspicuity. Quantitative parameters including CT attenuation and objective image noise (OIN) were determined. Results: In LDCT high iDose4™ levels lead to a significant decrease in OIN (FBP vs. iDose7: subscapular muscle 139.4 vs. 40.6 HU). The high iDose4™ levels provided significant improvements in image quality and artifact and noise reduction compared to LDCT FBP images. The conspicuity of subtle lesions was limited in LDCT FBP images. It significantly improved with high iDose4™ levels (> iDose4). LDCT with iDose4™ level 6 was determined to be of equivalent image quality as RDCT with FBP. Conclusion: iDose4™ substantially improves image quality and lesion conspicuity and reduces noise in low-dose chest CT. Compared to RDCT, high iDose4™ levels provide equivalent image quality in LDCT, hence suggesting a potential dose reduction of almost 80 %.

Two recent randomized controlled trials (RCT) consistently showed superiority of aggressive medical treatment versus percutaneous transluminal angioplasty and stenting (PTAS) in patients with intracranial artery stenosis. Patients with symptomatic basilar stenosis have a higher long-term risk of recurrent stroke compared to patients with anterior circulation stenosis but no study has specifically focused on the role of PTAS in this subgroup. The aim of our study was to investigate the subgroup of patients with symptomatic basilar artery stenosis to find evidence for the feasibility of a future clinical trial. Patients with ischemic stroke caused by a symptomatic basilar stenosis and admitted to five German tertiary care hospitals were included in this multicenter effectiveness study. Primary outcome was a composite endpoint of stroke recurrence, clinically relevant restenosis, progression and death. Shared frailty Cox regression models were used to compare outcome rates between groups. Of the 139 patients included in the study 79 (57 %) underwent PTAS and 60 (43 %) conservative treatment alone. The median follow-up period was 300 (IQR 18–738) days. Risks of the primary composite outcome (hazard ratio HR 0.49, 95 % confidence interval CI 0.25–0.97, p = 0.039) and of the key secondary outcomes recurrent stroke (HR 0.42, 95 % CI 0.19–0.95, p = 0.037) and clinically relevant restenosis/progression (HR 0.12, 95 % CI 0.03–0.59, p = 0.009) were lower in patients with PTAS compared to conservative treatment. There was no difference in all-cause mortality between groups (HR 0.98, 95 % CI 0.19–5.09, p = 0.979). In this retrospective study we could not reproduce the findings from large RCTs on intracranial stenting. Our data could be considered as a basis for a prospective study on patient selection for PTAS in the basilar artery.

Objectives Flat-panel CT (FPCT) allows cross-sectional parenchymal, vascular and perfusion imaging within the angiography suite, which could greatly facilitate acute stroke management. We hypothesized that FPCT offers equal diagnostic accuracy compared to multi-detector CT (MDCT) as a primary tool to exclude intracranial hemorrhage. Methods 22 patients with intracranial hematomas who had both MDCT and FPCT performed within 24 hours were retrospectively identified. Patients with visible change in hematoma size or configuration were excluded. Two raters independently segmented hemorrhagic lesions. Data sets and corresponding binary lesion maps were co-registered to compare hematoma volume. Diagnostic accuracy of FPCT to detect hemorrhage was calculated from voxel-wise analysis of lesion overlap compared to reference MDCT. Results Mean hematoma size was similar between MDCT (16.2±8.9 ml) and FPCT (16.1±8.6 ml), with near perfect correlation of hematoma sizes between modalities (ρ = 0.95, p