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Copyright of Die Radiologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This review will summarize artificial intelligence developments in acute ischemic stroke in recent years and forecasts for the future. Stroke is a major healthcare concern due to its effects on the patient's quality of life and its dependence on the timing of the identification as well as the treatment. In recent years, attention increased on the use of artificial intelligence (AI) systems to help categorize, prognosis, and to channel these patients toward the right therapeutic procedure. Machine learning (ML) and in particular deep learning (DL) systems using convoluted neural networks (CNN) are becoming increasingly popular. Various studies over the years evaluated the use of these methods of analysis and prediction in the assessment of stroke patients, and at the same time, several applications and software have been developed to support the neuroradiologists and the stroke team to improve patient outcomes. [ABSTRACT FROM AUTHOR]

Purpose: The use of robotics is emerging for performing interventional radiology procedures. Robots in interventional radiology are typically controlled using button presses and joystick movements. This study identified how different human–robot interfaces affect endovascular surgical performance using interventional radiology simulations. Methods: Nine participants performed a navigation task on an interventional radiology simulator with three different human–computer interfaces. Using Simulation Open Framework Architecture we developed a simulation profile of vessels, catheters and guidewires. We designed and manufactured a bespoke haptic interventional radiology controller for robotic systems to control the simulation. Metrics including time taken for navigation, number of incorrect catheterisations, number of catheter and guidewire prolapses and forces applied to vessel walls were measured and used to characterise the interfaces. Finally, participants responded to a questionnaire to evaluate the perception of the controllers. Results: Time taken for navigation, number of incorrect catheterisations and the number of catheter and guidewire prolapses, showed that the device-mimicking controller is better suited for controlling interventional neuroradiology procedures over joystick control approaches. Qualitative metrics also showed that interventional radiologists prefer a device-mimicking controller approach over a joystick approach. Conclusion: Of the four metrics used to compare and contrast the human–robot interfaces, three conclusively showed that a device-mimicking controller was better suited for controlling interventional neuroradiology robotics. [ABSTRACT FROM AUTHOR]

Successful endovascular treatment by stenting of intracranial aneurysms requires proper placement of the device and appropriate choice of its diameter and length. To date, several methods have been employed to achieve these goals, although each has inherent critical issues. Recently developed stent planning software applications can be used to assist interventional neuroradiologists. Based on a 3D-DSA image acquired before stenting, these applications simulate and visualize the final placement of the deployed stent. In this single-centre retrospective study, 27 patients undergoing an intravascular procedure for the treatment of intracranial aneurysms from June 2019 to July 2020 were evaluated according to strict inclusion criteria. Stent virtualization was performed with Syngo 3D Aneurysm Guidance Neuro software. We compared the software-generated stent measurement and measurements taken by the interventional radiologist. Statistical analysis was performed using the STAC web platform. Mean and standard deviations of absolute and relative discrepancies between predicted and implanted stents were recorded. Friedman's nonparametric test was used to refute the null hypotheses, i.e. (I) discrepancies between the size of virtual and implanted stents would occur, and (II) operator influence does not affect the outcome of the virtual stenting process. Based on these observations, it is believed that the virtual stenting process can validly assist interventional neuroradiologists in selecting the appropriate device and reducing peri- and post-procedural complications. The results of our study suggest that virtual reality simulation of devices used for endovascular treatment of intracranial aneurysms is a useful, rapid, and accurate tool for interventional procedure planning. [ABSTRACT FROM AUTHOR]

Purpose: Endovascular treatment of unruptured intracranial aneurysms (UIAs) requires a risk–benefit analysis and adherence to diagnostic reference levels (DRLs). The national DRL (250 Gy·cm2) is only determined for intracranial aneurysm coiling in general, including ruptured intracranial aneurysms (RIAs). This study aims to investigate the dose in the treatment of UIAs and RIAs separately. Methods: In a retrospective study design, dose area product (DAP) and fluoroscopy time (FT) were assessed for all patients undergoing intracranial aneurysm coiling between 2010 and 2021. DRL was set as the 75th percentile of the dose distribution. A multivariable linear regression analysis was performed to investigate DAP and FT for the two groups, UIA and RIA adjusted for patient age, aneurysm size, and location. Results: 583 (414 females, mean age 56.5 years, 311 UIAs) are included. In the overall population, DAP (median (IQR)) is 157 Gy·cm2 (108–217) with a median FT of 32.7 min (IQR 24.0–47.0). Local DRL is 183 Gy·cm2 for UIAs and 246 Gy·cm2 for RIAs. After adjustment for the other variables, the UIA and RIA groups have a significant effect on both DAP (p < 0.001; 95% CI − 68.432 – − 38.040) and FT (p < 0.001; 95% CI − 628.279 – − 291.254). In general, both DAP and FT increase significantly with patient age and aneurysm size, whereas the location of the aneurysm did not significantly change neither DAP (p = 0.171; 95% CI − 5.537–31.065) nor FT (p = 0.136; 95% CI − 357.391–48.508). Conclusion: Both aneurysm size and patient age were associated with increased DAP, whereas aneurysm location did not significantly change DAP or FT. The increased dose in patients with RIAs is likely equivalent to additional diagnostic cerebral four-vessel angiography performed in this group. [ABSTRACT FROM AUTHOR]

Purpose: Clinical outcome of stroke patients is usually classified into favorable (modified Rankin scale (mRS) 0–2) and unfavorable (mRS 3–5) outcome according to the modified Rankin scale. We took a closer look at the clinical course of thrombectomy stroke patients with formal unfavorable outcome and assessed whether we could achieve our treatment goals and/or neurological improvement in these patients. Methods: We studied 107 patients with occlusions in the terminal carotid artery or the M1 segment of the middle cerebral artery, in whom complete recanalization (eTICI 3) could be achieved, and who had an mRS of 3–5 at 90 days. We analyzed whether an individual treatment goal (i.e., preventing aphasia) and neurological improvement (NIHSS) could be achieved. In addition, we examined whether there was clinical improvement on the mRS. Results: The treatment goal was achieved in 52% (53/103) and neurological improvement in 65% (67/103). mRS 90 days post-stroke was better than mRS upon admission in 36% (38/107) and better than or equal to mRS upon admission in 80% (86/107). Of the 93 patients with known pre-stroke mRS, 18% (17/93) already had an mRS ≥ 3, with 15 of these 17 patients having a worse mRS on admission than before. Of these 17 patients, 18% regained baseline, and 24% improved from admission. Conclusion: Dichotomizing the mRS into favorable and unfavorable outcome does not do justice to the full spectrum of stroke. Patients with formal unfavorable outcome after mRS can improve neurologically, achieve treatment goals, and even regain their admission or pre-stroke mRS. [ABSTRACT FROM AUTHOR]

Purpose: The relationship between posterior-circulation lesion volume (PCLV) and clinical outcomes is poorly investigated. We aimed to analyze, in patients with acute basilar artery occlusion (ABAO), if pre-endovascular treatment (EVT) PCLV was a predictor of outcomes. Methods: We analyzed consecutive MRI selected, endovascularly treated ABAO patients. Baseline PCLV was measured in milliliters on apparent diffusion-coefficient map reconstruction. Univariable and multivariable logistic models were used to test if PCLV was a predictor of 90-day outcomes. After the received operating characteristic (ROC) analysis, the optimal cut-off was determined to evaluate the prognostic value of PCLV. Results: A total of 110 ABAO patients were included. The median PCLV was 4.4 ml (interquartile range, 1.3–21.2 ml). Successful reperfusion was achieved in 81.8% of cases after EVT. At 90 days, 31.8% of patients had a modified Rankin scale ≤ 2, and the mortality rate was 40.9%. PCLV was an independent predictor of functional independence and mortality (odds ratio [OR]:0.57, 95% confidence interval [CI], 0.34–0.93 and 1.84, 95% CI, 1.23–2.76, respectively). The ROC analysis showed that a baseline PCLV ≤ 8.7 ml was the optimal cut-off to predict the 90-day functional independence (area under the curve [AUC] = 0.68, 95% CI, 0.57–0.79, sensitivity 88.6%, and specificity 49.3%). In addition, a PCLV ≥ 9.1 ml was the optimal cut-off for the prediction of 90-day mortality (AUC = 0.71, 95% CI, 0.61–0.82, sensitivity 80%, and specificity 60%). Conclusions: Pre-treatment PCLV was an independent predictor of 90-day outcomes in ABAO. A PCLV ≤ 8.7 and ≥ 9.1 ml may identify patients with a higher possibility to achieve independence and a higher risk of death at 90 days, respectively. [ABSTRACT FROM AUTHOR]

Background: Delivery of most flow diverters (FD) requires larger, and thus stiffer microcatheters (0.021–0.027in.) which can pose challenges to intracranial navigation. The concomitant use of two microwires within one microcatheter, also known as the buddy-wire technique, may be helpful for navigation and support in challenging situations. Methods: We analyzed all flow diverter procedures in our prospectively collected database. We recorded all patient-related, anatomical and procedural information. We performed univariate statistics and technical descriptions. Results: In total, 208 consecutive patients treated with a FD at our institution between July 2014 and August 2020 were retrospectively analyzed. In 17 patients the buddy-wire technique was used (mean age 63 years, range 31–87 years: 16 female). Aneurysms were located at the petrous, cavernous, supraophthalmic internal carotid artery, and a proximal M2 branch in 2, 7, 7 and 1 patient(s), respectively. In all cases a 0.027in. microcatheter was used for device deployment. In 14 patients with a wide-necked aneurysm the buddy-wire provided additional support to advance the microcatheter and mitigated the ledge between the aneurysm neck and the parent artery or a side branch. In two giant cavernous aneurysms treated with telescoping FDs, the buddy-wire was used to re-enter the proximal end of the foreshortened FD. Conclusion: The buddy-wire is a useful technique in FD procedures to prevent herniation of the microcatheter into the aneurysm sack, in wide-necked aneurysms to mitigate the ledge effect between the aneurysm neck and the parent artery where the microcatheter tip may get stuck, or to enable re-entry into a foreshortened FD. [ABSTRACT FROM AUTHOR]

Purpose: Different embolization techniques and materials are available for the pre-operative embolization of carotid body paragangliomas. In this study, we report the first experience of the direct percutaneous puncture technique under fluoroscopic guidance using the low-viscosity formula of SQUID-12. The additional use of a transitory balloon-blockage at the origin of the external carotid artery aims to confer higher protection by limiting the risk of non-target embolization and subsequent neurological sequelae. Materials and Methods: We retrospectively reviewed all cases of carotid body paragangliomas that have undergone pre-surgical embolization with a direct puncture technique and balloon-assistance at our institution between 2019 and 2020. The use of the liquid EVOH-based SQUID-12 as the sole embolic agent was the main inclusion criteria. Results: A total of 9 patients with 9 carotid body paragangliomas were enrolled in this case series. The mean volume of the lesion was 309 mm3. The mean embolization-session time amounted to 88 min. The average number of needles inserted was 2, and the mean volume of SQUID-12 used per case was 23 ml. Successful total devascularization was obtained in all cases. No long-term sequelae due to the embolization procedure occurred. Conclusions: Pre-operative paraganglioma embolization with SQUID-12 using a direct puncture and balloon-assisted technique is a safe and efficient method with few complications. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to determine local diagnostic reference levels (DRLs) in the endovascular therapy (EVT) of patients with cranial and spinal dural arteriovenous fistula (dAVF). Methods: In a retrospective study design, DRLs and achievable dose (AD) were assessed for all patients with cranial and spinal dAVF undergoing EVT (I) or diagnostic angiography (II). All procedures were performed at the flat-panel angiography-system Allura Xper (Philips Healthcare). Interventional procedures were differentiated according to the region of fistula and the type of procedure. Results: In total, 264 neurointerventional procedures of 131 patients with dAVF (94 cranial, 37 spinal) were executed between 02/2010 and 12/2020. The following DRLs, AD, and mean values could be determined: for cranial dAVF (I) DRL 507.33 Gy cm2, AD 369.79 Gy cm2, mean 396.51 Gy cm2; (II) DRL 256.65 Gy cm2, AD 214.19 Gy cm2, mean 211.80 Gy cm2; for spinal dAVF (I) DRL 482.72 Gy cm2, AD 275.98 Gy cm2, mean 347.12 Gy cm2; (II) DRL 396.39 Gy cm2, AD 210.57 Gy cm2, mean 299.55 Gy cm2. Dose levels of EVT were significantly higher compared to diagnostic angiographies (p < 0.001). No statistical difference in dose levels regarding the localization of dAVF was found. Conclusion: Our results could be used for establishing DRLs in the EVT of cranial and spinal dAVF. Because radiation exposure to comparably complex interventions such as AVM embolization is similar, it may be useful to determine general DRLs for both entities together. [ABSTRACT FROM AUTHOR]

Background and Purpose: The principle of flow diversion has revolutionized the treatment of brain aneurysms. In this study, we report our experience of the new Surpass Evolve (SE) flow diverter in the treatment of intracranial aneurysms. Material and Methods: Patients were treated with the SE as first-line therapy between May 2019 and June 2020 at 2 experienced institutions. Inclusion criteria were wide-necked, blister-like, or fusiform/dissecting aneurysms in the anterior and posterior circulation. Primary endpoint was technical success defined as favorable navigation to the target vessel and successful deployment of the SE. Secondary endpoints were favorable aneurysm occlusion defined as O'Kelly Marotta (OKM) scale C1-3 + D on follow-up, procedure-related complications and retreatment. Results: A total of 46 aneurysms in 42 patients were treated with 57 SE flow diverters. Median aneurysm size was 6.6 mm (IQR 4.0–12.2 mm) with a median neck width of 4 mm (IQR 2.2–5.4 mm). On admission, 6 (13%) aneurysms were ruptured and 41 (89%) were located in the anterior circulation. The primary endpoint was reached in 96%. Median follow-up was 116 days (IQR 92–134 days) and available for 36/46 (78%) aneurysms. Favorable aneurysm occlusion was seen in 31/36 (86%) aneurysms and 27/36 (75%) were occluded completely. Parent artery occlusion appeared in 3 (3%) patients on follow-up and 2 aneurysms (6%) required additional treatment due to insufficient closure. Conclusion: The new SE flow diverter is safe and seems to be effective with promising occlusion rates at short-term follow-up. [ABSTRACT FROM AUTHOR]

Copyright of Der Radiologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background and Purpose: The aim of this study was to assess the safety and effectiveness of lateral sinus stenosis (LSS) stenting in patients with idiopathic intracranial hypertension (IIH) who are refractory to medical treatment, particularly focusing on visual outcomes including papilledema. Material and Methods: Retrospective study of consecutive patients with IIH refractory to medical treatment who underwent LSS stenting. Clinical features, visual fields and optical coherence tomography (OCT) retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) thicknesses were assessed before stenting, at 1 month poststenting and at last follow-up. Complications were also recorded. Results: A total of 16 women were included, with a mean age of 39 ± 11 years. All patients had papilledema while 15/16 (94%) had headaches. Mean visual acuity was 0.036 logMAR, range (+0.4 to +0.0 logMAR). The mean RNFL thickness prior to stenting was 121.7 µm (±34.7 µm) and mean GCL thickness was 80.2 µm (±8.9 µm). Mean follow-up was 19.7 months (±11.8 months). After stenting, acetazolamide was discontinued in 15/16 (94%) patients. Papilledema improved in 14/16 (88%) of patients. The mean RNFL thickness was significantly decreased 1 month after stenting (96.3 ± 15.6 µm; p < 0.001) and at last visit (93.4 ± 15.3 µm; p < 0.001). The GCL thickness after LSS stenting was moderately decreased at the last visit examination: 80.2 ± 8.9 µm vs. 78.0 ± 10.7 µm; (p < 0.01). No stent-related complication occurred, while there was one case of restenosis. Conclusion: Improvement of papilledema appears to occur relatively rapidly after the LSS stenting. The results further support the role of LSS stenting in the treatment of IIH, especially with respect to visual symptoms. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to determine local diagnostic reference levels (LDRLs) of intra-arterial chemotherapy (IAC) procedures of pediatric patients with retinoblastoma (RB) to provide data for establishing diagnostic reference levels (DRLs) in pediatric interventional radiology (IR). Methods: In a retrospective study design, LDRLs and achievable dose (AD) were assessed for children undergoing superselective IAC for RB treatment. All procedures were performed at the flat-panel angiography systems (I) ArtisQ biplane (Siemens Healthineers) and (II) Allura Xper (Philips Healthcare). Patients were differentiated according to age (A1: 1–3 months; A2: 4–12 months; A3: 13–72 months; A4: 73 months–10 years; A5: > 10 years), sex, conducted or not-conducted chemotherapy. Results: 248 neurointerventional procedures of 130 pediatric patients (median age 14.5 months, range 5–127 months) with RB (68 unilateral, 62 bilateral) could be included between January 2010 and March 2020. The following diagnostic reference values, AD, and mean values could be determined: (A2) DRL 3.9 Gy cm2, AD 2.9 Gy cm2, mean 3.5 Gy cm2; (A3) DRL 7.0 Gy cm2, AD 4.3 Gy cm2, mean 6.0 Gy cm2; (A4) DRL 14.5 Gy cm2, AD 10.7 Gy cm2, mean 10.8 Gy cm2; (A5) AD 8.8 Gy cm2, mean 8.8 Gy cm2. Kruskal-Wallis-test confirmed a significant dose difference between the examined age groups (A2–A5) (p < 0.001). There was no statistical difference considering sex (p = 0.076) and conducted or not-conducted chemotherapy (p = 0.627). A successful procedure was achieved in 207/248 cases. Conclusion: We report on radiation exposure during superselective IAC of a pediatric cohort at the German Retinoblastoma Referral Centre. Although an IAC formally represents a therapeutic procedure, our results confirm that radiation exposure lies within the exposure of a diagnostic interventional procedure. DRLs for superselective IAC are substantially lower compared with DRLs of more complex endovascular interventions. [ABSTRACT FROM AUTHOR]

Purpose: Brain arteriovenous malformations (bAVM) are the main cause of pediatric intracerebral hemorrhage (pICH). Embolization with Onyx (ev3, Irvine, CA, USA) in children with ruptured bAVM has been infrequently reported. The aim of this study was to assess the safety and efficacy profile of Onyx embolization as first line endovascular treatment of ruptured pediatric bAVMs. Methods: Children with non-traumatic pICH due to bAVM rupture at a pediatric quaternary care center were prospectively enrolled in a registry and retrospectively analyzed between 2013 and 2018. Clinical and demographic data, treatment modalities and clinical imaging follow-up were retrieved, and detailed procedural data were retrospectively assessed by two investigators. The safety (procedural morbidity and mortality) and efficacy (obliteration and interval rebleeding) were evaluated. Results: In this study 29 children treated for a bAVM by Onyx embolization were included (14 girls, 48%; median age 11.1 years, interquartile range, IQR 8.1–12.7 years) with a total of 72 endovascular sessions (median of 2 sessions per patient IQR 1–3). The AVMs were deeply located in 23 patients (79%). No systemic complications occurred, and no child experienced embolization-related persistent neurological deficits. Non-clinically relevant complications were observed during five procedures, unrelated to Onyx. After a mean follow-up of 31 months from rupture complete obliteration rates were 100%, 89%, 29%, 14% in bAVM Spetzler Martin grades I, II, III and IV–V, respectively. Conclusion: It was found that Onyx embolization is safe and represents a good option for an initial treatment approach, in a sequential treatment strategy for pediatric ruptured brain AVMs. Younger age may not be an argument to deny Onyx embolization. [ABSTRACT FROM AUTHOR]

Tremor is a common and very disabling symptom in patients with essential tremor and Parkinson's disease. In the recent years, transcranial ablation of thalamic nuclei using magnetic resonance guided high-intensity focused ultrasound has emerged as a minimally invasive treatment for tremor. The aim of this review is to discuss, in the light of our single-center experience, the technique, current applications, results, and future perspectives of this novel technology. [ABSTRACT FROM AUTHOR]

Purpose: Endovascular treatment of unruptured intracranial aneurysms with stent-assisted coiling or flow diverter stents requires a prophylactic antiplatelet premedication to avoid thrombo-embolic complications. Guidelines for optimal antiplatelet regimens are poorly defined. The aim of this study is to report our experience using a high dosage antiplatelet premedication regimen for patients with unruptured intracranial aneurysms undergoing endovascular treatment by stent-assisted coiling or flow diverter stents. Methods: From a retrospective analysis of a prospectively maintained database, we collected clinical and angiographic data of 400 procedures in 362 patients treated by stent-assisted coiling or flow diverter stents for 419 unruptured intracranial aneurysms. Descriptive and analytic statistics were performed to report morbidity, mortality, and complication rates and to demonstrate associations between variables and outcomes. Logistic multivariable regression was performed to rule out confounding factors between subgroups. Results: Thrombo-embolic complications occurred in 23/400 procedures (5.75%) and hemorrhagic complications in 19/400 procedures (4.75%). The majority of complications were minor and transient with overall procedure-related morbidity and mortality rates of 1.75% (n = 7/400) and 1.25% (n = 5/400) respectively. The co-existence of multiple cardiovascular risk factors among smoking, hypertension, dyslipidemia, and age > 65 years old was significantly associated with permanent procedure-related morbidity (p = 0.006) and thrombo-embolic complications occurrence (p = 0.034). Age alone was associated with higher permanent morbidity (p = 0.029) and was the only variable associated with higher hemorrhagic complication (p = 0.024). Conclusion: In this study, the use of a high dosage antiplatelet premedication was safe and effective for the treatment of unruptured intracranial aneurysms with stent-assisted coiling or flow diverter stents. Mortality and morbidity rates compare favorably with the current literature. The thrombo-embolic complications rate is low and most of them were clinically silent. However, the hemorrhagic complications rate was substantial and a significant proportion of them were associated with mortality. [ABSTRACT FROM AUTHOR]

Copyright of Der Radiologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose of review: Endovascular thrombectomy (ET), the standard of treatment for emergent large vessel occlusion (ELVO) strokes, has been subject to rigorous efforts to further improve its usage and delivery for optimised patient outcomes. This review aims to provide an outline and discussion about the recently established and emerging recommendations regarding endovascular treatment of stroke. Recent findings: The indications for ET have expanded continually, with perfusion imaging now enabling selection of patients presenting 6–24 h after last-known-well, and improved device and operator proficiency allowing treatment of M2-MCA occlusions and tandem occlusions. Further inclusion of paediatric patients and patients with larger infarct core or milder stroke symptoms for ET has been proposed; however, this remains unproven. This growing applicability is supported by more efficient systems of care, employing modern techniques such as telemedicine, mobile stroke units and helicopter medical services. Ongoing debate exists regarding thrombolytic agent, thrombectomy technique, anaesthesia method and the role of advanced neuroimaging, with upcoming RCTs expected to provide clarification. Summary: The journey to further improving the efficacy of ET has advanced and diversified rapidly over recent years, involving improved patient selection, increased utility of advanced neuroimaging and ongoing device redevelopment, within the setting of more efficient, streamlined systems of care. This dynamic and ongoing influx of evidence-based refinements is key to further optimising outcomes for ELVO patients. [ABSTRACT FROM AUTHOR]

Purpose: In the last 10 years, intra-arterial chemotherapy (IAC) has been increasingly used in the clinical management of retinoblastoma. It is reported to provide tumor control even in advanced stage disease that might have previously required enucleation. In our clinical experience, there are three conditions that may impair the use of IAC: (1) significant collaterals to meningeal arteries, (2) technical failure of ophthalmic artery catheterization, or (3) retina blood supply from collaterals different to the ophthalmic artery. In the current study, we assessed the rate of IACs that could not be carried out in our institution due to these three reasons.Methods: All patients admitted for IAC in our hospital were retrospectively assessed by chart review. Non-application rate of IAC was assessed and classified according to the three abovementioned criteria. Complication rate of both finalized and interrupted interventions was recorded.Results: Ninety-eight patients (median age 21.4 months, range 5.3 months-10.5 years) were identified. IAC was performed in 69 (70.4%) patients and interrupted in 12 (12.2%) cases because of meningeal collaterals, in 8 (8.2%) because of technical failure to cannulate the ophthalmic artery, and in 9 (9.2%) because of alternative blood supply of the retina.Conclusion: The rather defensive approach that is pursued in our center resulted in an overall non-application rate of IAC around 30%. The relatively high probability of conditions that impair the use of IAC needs to be addressed adequately in the patient conversation prior to the procedure. Our rate of 8% of abstention from IAC due to technical limitations might be reduced by the application of more rigorous therapeutic approaches such as balloon occlusion of the distal internal carotid artery. More research is finally needed to determine if IAC can be safely performed in the presence of meningeal collaterals and via branches of the external carotid artery. [ABSTRACT FROM AUTHOR]

Purpose: Knowledge about the localization and outcome of iatrogenic dissection (ID) during endovascular treatment of acute ischemic stroke (AIS) is limited. We aimed to determine the frequency, clinical aspects and morphology of ID in endovascular AIS treatment and to identify predictors of this complication.Methods: Digital subtraction angiography (DSA) of ID carried out during endovascular treatment between January 2000 and March 2012 have been re-evaluated. The ID localization and morphology were analyzed and related to the interventional techniques. Baseline clinical and radiological findings, treatment modality and outcome were compared with patients without ID.Results: Out of 866 patients 18 (2%) suffered an ID (44% female, median age 64 years). Localization was extracranial in 15 (83%, 14 internal carotid artery and 1 vertebral artery) and intracranial in 3 (17%; 1 vertebrobasilar dissection and 2 in the anterior circulation). Of the IDs 5 (28%) resulted in a high-degree, 3 (17%) in a moderate, 5 (28%) in a mild and 5 (28%) in no stenosis and 8 IDs were stented in the acute phase. At 3 months 7 (42%) patients had a favorable outcome (modified Rankin score mRS ≤ 2) and 6 (33%) patients had died. Patients with ID had a different stroke etiology (p = 0.041), were more likely to be smokers (44% versus 19%, p = 0.015) and were more likely to be treated with mechanical thrombectomy (100% versus 60%, p < 0.001). Although two ID patients had relevant complications, the outcome did not differ between the groups.Conclusion: The occurrence of ID is a rare complication of endovascular AIS treatment associated with smoking and mechanical thrombectomy. [ABSTRACT FROM AUTHOR]

Purpose: Pediatric neuroendovascular procedures require special considerations. Given small vessel sizes, risk for arterial injury must be weighed against use of larger devices, with the diameter of the sheath being a known association with arterial complications. We recently transitioned to using thin-walled radial sheaths for transfemoral angiography in children, given their lower profile. Here, we report on these sheaths' technical success and complications, comparing against a historical cohort where regular vascular sheaths were employed. Methods: We retrospectively recorded patient and procedural data from 168 consecutive procedures from September 2017 to January 2019 when radial-specific sheaths were exclusively used at our tertiary pediatric hospital. These results were compared to data from September 2015 to January 2017, when regular vascular sheaths were exclusively used in 152 consecutive procedures. Statistical analysis was performed using unpaired t test or chi-square test, with p < 0.05 considered statistically significant. Results: Patient characteristics (age, sex, weight) were not statistically different between the case and control group. No significant differences were found in the procedural data with the exception of heparin use which was higher in the radial-sheath cohort. There was a decrease in the rate of complications in the case group (1.2%) versus control group (2.6%), though not statistically different. Conclusion: Radial-specific sheaths have numerous beneficial characteristics that make them well-suited to the pediatric population. In our study, we show that radial sheaths are equally effective and safe perioperatively. Follow-up research may show if radial sheaths used transfemorally decrease long-term complications such as limb-length discrepancy and mortality. [ABSTRACT FROM AUTHOR]

Background: Recently published clinical trials have resulted in a significant change in the guidelines used to manage patients suffering an acute ischaemic stroke. New neuro-interventional techniques have revolutionised stroke outcomes. Currently, such services are only available in two specialist centres.Aims: We attempted to evaluate the need for the provision of routine computed tomography (CT) angiography and neuro-interventional services at a university teaching hospital in Limerick.Methods: A retrospective study was performed based on data collated by the stroke service, University Hospital Limerick (UHL). All patients with a suspected acute ischaemic stroke of anterior circulation and known evolution were included. Baseline clinical and imaging characteristics, thrombolysis data, stroke unit admission rates and discharge destinations were recorded.Results: All 141 patients were suitable for CT angiography and should be performed in accordance with guidelines. Additionally, 165 patients excluded from the study due to an unknown stroke evolution timeframe may have benefitted. Non-contrast CT scan confirmed just 12 anterior circulation strokes. The need for neuro-interventional services proved more difficult to assess, primarily due to the lack of provision of routine CT angiography, employed to confirm anterior circulation occlusion. Secondary results showed a thrombolysis rate of 10.8% and confirmed that time efficiencies result in higher thrombolysis eligibility rates. Stroke unit admissions and discharge destinations were also recorded.Conclusion: UHL should provide routine CT angiography to all patients presenting with acute ischaemic stroke in line with current guidelines. The need for provision of neuro-interventional services on-site proved more difficult to assess and requires further analysis. [ABSTRACT FROM AUTHOR]

Purpose: A pseudo-normalization of infarcted brain parenchyma, similar to the 'fogging effect' which usually occurs after 2-3 weeks, can be observed on CT performed immediately after endovascular stroke treatment (EST). Goal of this study was to analyze the incidence of this phenomenon and its evolution on follow-up imaging. Methods: One hundred fifty-two patients in our database of 949 patients, who were treated for acute stroke between January 2010 and January 2015, fulfilled the inclusion criteria of (a) EST for an acute stroke in the anterior circulation, (b) an ASPECT-score < 10 on pre-interventional CT, and (c) postinterventional CT imaging within 4.5 h after the procedure. Two independent reviewers analyzed imaging data of these patients. Results: Transformation of brain areas from hypoattenuated on pre-interventional CT to isodense on postinterventional CT was seen in 37 patients in a total of 49 ASPECTS areas (Cohen's kappa 0.819; p < 0.001). In 17 patients, the previously hypoattenuated brain areas became isodense, but appeared swollen. In 20 patients (13%), the previously hypodense brain area could not be distinguished from normal brain parenchyma. On follow-up imaging, all isodense brain areas showed signs of infarction. Conclusion: Pseudo-normalization of infarct hypoattenuation on postinterventional CT is not infrequent. It is most likely caused by contrast leakage in infarcted parenchyma and does not represent salvage of ischemic brain parenchyma. [ABSTRACT FROM AUTHOR]

Objectives: To describe, in a multicentric paediatric population, reference levels (RLs) for three interventional radiological procedures.Methods: From January 2012 to March 2015, children scheduled for an interventional radiological procedure in two French tertiary centres were retrospectively included and divided into four groups according to age: children younger than 2 years (A1), aged 2-7 years (A5), 8-12 years (A10) and 13-18 years (A15). Three procedures were identified: cerebral digital subtraction angiography (DSA), brain arteriovenous malformation (bAVM) embolization, and head and neck superficial vascular malformation (SVM) percutaneous sclerotherapy. Demographic and dosimetric data, including dose area product (DAP), were collected.Results: 550 procedures were included. For DSA (162 procedures), the proposed RL values in DAP were 4, 18, 12 and 32 Gy∙cm2 in groups A1, A5, A10 and A15, respectively. For bAVM embolization (258 procedures), values were 33, 70, 105 and 88 Gy∙cm2 in groups A1, A5, A10 and A15, respectively. For SVM sclerotherapy (130 procedures), values were 350, 790, 490 and 248 mGy∙cm2 in groups A1, A5, A10 and A15, respectively.Conclusion: Consecutive data were available to permit a proposal of reference levels for three major paediatric interventional radiology procedures.Key Points: • We determined reference levels (RLs) for bAVM embolization, DSA and SVM sclerotherapy. • The proposed RLs will permit benchmarking practice with an external standard. • The proposed RLs by age may help to develop paediatric dose guidelines. [ABSTRACT FROM AUTHOR]

Purpose: Interaction with radiological image data and volume renderings within a sterile environment is a challenging task. Clinically established methods such as joystick control and task delegation can be time-consuming and error-prone and interrupt the workflow. New touchless input modalities may have the potential to overcome these limitations, but their value compared to established methods is unclear. Methods: We present a comparative evaluation to analyze the value of two gesture input modalities (Myo Gesture Control Armband and Leap Motion Controller) versus two clinically established methods (task delegation and joystick control). A user study was conducted with ten experienced radiologists by simulating a diagnostic neuroradiological vascular treatment with two frequently used interaction tasks in an experimental operating room. The input modalities were assessed using task completion time, perceived task difficulty, and subjective workload. Results: Overall, the clinically established method of task delegation performed best under the study conditions. In general, gesture control failed to exceed the clinical input approach. However, the Myo Gesture Control Armband showed a potential for simple image selection task. Conclusion: Novel input modalities have the potential to take over single tasks more efficiently than clinically established methods. The results of our user study show the relevance of task characteristics such as task complexity on performance with specific input modalities. Accordingly, future work should consider task characteristics to provide a useful gesture interface for a specific use case instead of an all-in-one solution. [ABSTRACT FROM AUTHOR]

Introduction: Ventral sulcus spinal cord arteriovenous shunts (SCAVS) are rare vascular lesions that are located outside the spinal cord, are exclusively vascularized by the anterior spinal axis, and drain exclusively through the anterior spinal vein. We report the anatomical, clinical, and neuro-radiological features of SCAVS managed by our team. Methods: We conducted a retrospective study of patients with SCAVSs evaluated by the senior author of this report (GR) between 1981 and 2014. Data were collected by reviewing clinical notes and by a systematic analysis of spinal angiograms and MRI. Results: Among 358 patients, we identified 8 patients (3 women) with ventral sulcus spinal cord arteriovenous shunts. Mean age was 30.5 years. Six patients presented with progressive neurological symptoms, and two with acute neurological symptoms related to hematomyelia. Three shunts were located in the cervical cord, four in the thoracic cord, and one at the conus medullaris; there were two nidus type A-V shunts (AVMs) and six fistula type A-V shunts (AVFs). Seven patients were treated by endovascular therapy with glue embolization. Embolization led to anatomical cure in 5 cases, and a significant reduction of shunt volume and flow of more than 75% in 2 cases. In none of the cases we observed permanent morbidity. Conclusions: AVS of the ventral sulcus of the spinal cord are rare. Recognition of these lesions and precise localization of the anatomical space in which they are located, may allow a better understanding of their pathophysiology and clinical manifestations and guide proper therapeutic decisions. [ABSTRACT FROM AUTHOR]

Background: The objective of this study was to analyse the Neurothrombectomy Network registry of the Neuromed Campus (NMC) of the Kepler University Hospital in Linz (Austria). The data were compared to the results of recently published thrombectomy trials (MR CLEAN, ESCAPE, EXTEND-IA, SWIFT-PRIME, REVASCAT and THRACE). Methods: We retrospectively studied 246 patients with acute ischemic stroke who underwent thrombectomy between January 2012 and December 2015 at the NMC in Upper Austria. The main outcome measures were modified Rankin scale (mRS) score 0-2 at 90 days, all-cause mortality and stroke or thrombectomy-related mortality at discharge, as well as 90 days postdischarge. Results: The median age was 70.4 years (IQR 59.9-76.9) and the median NIHSS at admission 16 (IQR 13-20). The thrombolysis in cerebral infarction (TICI) scale 2b-3 recanalization was achieved in 87.4%, 11.0% of the patients died in hospital and an additional 6.1% within 90 days after discharge. After 90 days, 56.5% had a mRS score 0-2. Conclusions: These data suggest that the positive results of thrombectomy reported in several randomized controlled studies can be achieved in routine clinical practice; therefore, the setting of an organized, regional stroke network proved an effective and appropriate method for delivering regional thrombectomy stroke treatment. [ABSTRACT FROM AUTHOR]

Introduction: Spontaneous dissections of intracranial arteries are rare, but important causes of stroke, especially in younger patients. Dissections of the anterior cerebral artery (ACA) have been reported only very rarely in the European and North American populations but might be more prevalent than previously thought. Methods: This paper describes the presenting pattern of the disease, the clinical and imaging findings, as well as endovascular therapeutical options with respect to a meta-analysis of cases reported in the literature. Additionally, own observations in three recent representative cases are discussed. Results: Overall, 80 cases from recent literature were included to the meta-analysis. The median age was 51 (35-82) years. Ischemia alone was described in 58 cases (73 %), subarachnoid hemorrhage (SAH) in 8 cases (10 %), and a combination of both in 14 cases (17 %). Radiological diagnosis including use of thin-layered 3T-MRI vessel wall imaging with black blood technique was verified by double lumen, by a string sign or string and pearl sign, or by a vessel wall hematoma in 23 (32 %), 62 (89 %), and 14 (20 %) cases, respectively. Interventional or surgical treatment was performed in 7 cases. A good clinical recovery was achieved in 77 % of cases. Conclusion: Dissections of the ACA mostly cause ischemia, but can cause SAH or a combination of both in a relatively young population. Detailed neuroradiological diagnosis including 3T-MRI vessel wall imaging is required as a double lumen, isolated stenosis due to vessel wall hematoma, or the secondary development of a pseudoaneurysm might occur. Interventional therapy is the primary therapy for these vascular complications. [ABSTRACT FROM AUTHOR]

Introduction: Treatment of complex anterior circulation aneurysms with flow diverters (FDs) has become common practice in neurovascular centers. However, this treatment method for posterior circulation aneurysms (PCAs) still remains controversial. Methods: Through searches for reports on the treatment of PCAs with FDs, we conducted a systematic review of the literature on its clinical efficacy and safety using random-effect binomial meta-analysis. Results: We included 14 studies, which reported on a total of 225 PCAs in 220 patients. Procedure-related good outcome rate was 79 % (95 % confidence interval (CI), 72-84), with significantly lower odds among patients with ruptured aneurysms and basilar artery aneurysms. Procedure-related mortality rate was 15 % (95 % CI 10-21), with significantly higher rates among patients with giant aneurysms and basilar artery aneurysms. The rate of complete aneurysm occlusion at 6-month digital subtraction angiography (DSA) was 84 %. Ischemic stroke rate was 11 %. Perforator infarction rate was 7 %. Postoperative subarachnoid hemorrhage (SAH) rate was 3 %. Intraparenchymal hemorrhage (IPH) rate was 4 %. Conclusions: Flow diverter treatment of PCAs is an effective method, which provides a high rate of complete occlusion at 6-month DSA. However, compared with anterior circulation aneurysms, patients with PCAs are at significantly higher risk of mortality, ischemic stroke and perforator infarction. Our findings indicate that, in most clinical centers, flow diverter treatment of PCAs should be conducted in carefully selected patients with poor natural history and no optimal treatment strategy. For ruptured and giant basilar artery aneurysms, there is still no good treatment option. [ABSTRACT FROM AUTHOR]

Introduction: We have conducted a prospective study to clinically evaluate a new radiation dose observing tool that displays patient's peak skin dose (PSD) map in real time. Methods: The skin dose map (SDM) prototype quantifies the air kerma based on exposure parameters from the X-ray system. The accuracy of this prototype was evaluated with radiochromic films, which were used as a mean for PSD measurement. Results: The SDM is a reliable tool that provides an accurate PSD estimation and location. Conclusion: SDM also has many advantages over the radiochromic films, such as real-time dose evaluation and easy access to critical operational parameters for physicians and technicians. [ABSTRACT FROM AUTHOR]

Introduction: There is currently no standardised approach to arteriovenous malformation (AVM) reporting. Existing AVM classification systems focuses on angioarchitectural features and omit haemodynamic, anatomical and topological parameters intuitively used by therapists. Methods: We introduce a symbolic vocabulary to represent the state of an AVM of the brain at different stages of treatment. The vocabulary encompasses the main anatomic and haemodynamic features of interest in treatment planning and provides shorthand symbols to represent the interventions themselves in a schematic representation. Results: The method was presented to 50 neuroradiologists from14 countries during a workshop and graded 7.34 ± 1.92 out of ten for its usefulness as means of standardising and facilitating communication between clinicians and allowing comparisons between AVM cases. Feedback from the survey was used to revise the method and improve its completeness. For an AVM test case, participants were asked to produce a conventional written report and subsequently a diagrammatic report. The two required, on average, 6.19 ± 2.05 and 5.09 ± 3.01 min, respectively. Eighteen participants said that producing the diagram changed the way they thought about the AVM test case. Conclusion: Introduced into routine practice, the diagrams would represent a step towards a standardised approach to AVM reporting with consequent benefits for comparative analysis and communication as well as for identifying best treatment strategies. [ABSTRACT FROM AUTHOR]

Introduction: The purpose of this study was to quantify the reduction in patient radiation dose by X-ray imaging technology using image noise reduction and system settings for neuroangiography and to assess its impact on the working habits of the physician. Methods: Radiation dose data from 190 neuroangiographies and 112 interventional neuroprocedures performed with state-of-the-art image processing and reference system settings were collected for the period January-June 2010. The system was then configured with extra image noise reduction algorithms and system settings, which enabled radiation dose reduction without loss of image quality. Radiation dose data from 174 neuroangiographies and 138 interventional neuroprocedures were collected for the period January-June 2012. Procedures were classified as diagnostic or interventional. Patient radiation exposure was quantified using cumulative dose area product and cumulative air kerma. Impact on working habits of the physician was quantified using fluoroscopy time and number of digital subtraction angiography (DSA) images. Results: The optimized system settings provided significant reduction in dose indicators versus reference system settings ( p<0.001): from 124 to 47 Gy cm and from 0.78 to 0.27 Gy for neuroangiography, and from 328 to 109 Gy cm and from 2.71 to 0.89 Gy for interventional neuroradiology. Differences were not significant between the two systems with regard to fluoroscopy time or number of DSA images. Conclusion: X-ray imaging technology using an image noise reduction algorithm and system settings provided approximately 60% radiation dose reduction in neuroangiography and interventional neuroradiology, without affecting the working habits of the physician. [ABSTRACT FROM AUTHOR]

Introduction: Cerebral arteriovenous shunts (CAVS) in the pediatric population cannot be compared to those in adults as they present different anatomical, physiological, and pathological characteristics concerning the arterial and venous vasculature and the cerebrospinal fluid physiology. These lesions develop in a maturing brain, of which expression is difficult to assess, with a potential for recovery different from that in adults. Discussion: Their impact on the brain will be different in the antenatal period, in neonates, in infants, and in children, with variable symptoms according to each age group. We review different classifications of pediatric CAVS (according to the anatomical space in which they develop, their type and architecture, and the age at which they reveal), describe their evolution, and discuss the current role of endovascular treatment in the management of these vascular lesions. [ABSTRACT FROM AUTHOR]

Based on current data and experience, the joint working group of the European Society of Minimally Invasive Neurological Therapy (ESMINT) and the European Society of Neuroradiology (ESNR) make suggestions on trial design and conduct aimed to investigate therapeutic effects of mechanical thrombectomy (MT). We anticipate that this roadmap will facilitate the setting up and conduct of successful trials in close collaboration with our neighbouring disciplines. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the study was to examine the effects of mechanical thrombectomy using the Solitaire stent in patients with thromboembolic occlusions of the intracranial carotid artery bifurcation (carotid T) or middle cerebral artery (MCA) and to compare the results with a historical cohort treated with local intraarterial thrombolysis using urokinase. Methods: The time intervals from stroke onset to treatment, recanalization rates, occlusion sites, recanalization times and functional outcomes on the modified Rankin scale at 3 months in 25 patients treated with the Solitaire stent between 2010 and 2011 were evaluated. The data were compared with those of a historical cohort of 62 patients treated with local intraarterial thrombolysis between 1992 and 2001. Results: A total of 15 out of 25 (60%) patients treated with mechanical thrombectomy and 25 out of 62 (40%) treated with local intraarterial thrombolysis achieved a modified Rankin score of £ 2 (p = 0.07). Occlusion sites, intervals from stroke onset to treatment and rates of parenchymal hematomas, 3 out of 25 (12%) versus 8 out of 62 (13%), were similar in both cohorts while the recanalization rate was significantly higher, 22 out of 25 (88%) versus 33 of 62 (53%), in the mechanical thrombectomy group (p £ 0.01). Conclusion: The data show that mechanical thrombectomy is superior to local intraarterial thrombolysis with respect to the recanalization rate in patients with thrombeoembolic carotid T or MCA occlusions. [ABSTRACT FROM AUTHOR]

Three randomised controlled trials (RCTs) comparing outcomes after carotid artery stenting (CAS) with carotid endarterectomy (CEA) have recently been published. Recent systematic reviews have recommended that CAS is no longer justified for patients suitable for CEA. Indeed, in many centres, pooled data of RCTs show higher peri-operative risk of performing CAS vs. CEA with comparable long-term efficacy. Due to limitations in SPACE, EVA3S and ICSS study design and conduct, the inferiority of CAS to CEA as a method remains inconclusive. The goal of this review is not to discredit these trials but to develop a more differentiated and critical interpretation of the data and to create more discussion. It will discuss the necessity of RCTs for Interventional Neuroradiology in general and particular problems in study design (non-inferiority design and interpretation of results, clinical equipoise, study endpoints), practical study conduct difficulties (operator and centre experience, antiaggregation, timing of treatment) and the interpretation of the results (relation of internal and external validity, procedural complexity, the 68-year surprise, longer-term outcome). A premature rejection of CAS based on the data from these studies could harm future patients who would have had benefited from this procedure. For the time being, there is no reason why centres with good and independently controlled track records should stop performing CAS. Designing a single cooperative European trial that incorporates the lessons learned would be major step forward. [ABSTRACT FROM AUTHOR]

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Detailed descriptions of the mastoid emissary veins (MEVs) and the foramina through which they travel are lacking in the literature. Therefore, the aim of our study was to explore and delineate the morphology, topography and morphometry of the MEV, mastoid foramen (MF) and occipital foramen (OF). One hundred cadaver heads and 100 dried human skulls were grossly examined The MF and OF varied from being absent to having as many as four small openings, each transmitting an emissary vein. The overall prevalence of MEV was 98% on the right and 72% on the left. The overall prevalence of OF was 7% on the right and 4% on the left. The mean length of the MEV from its point of origin to its point of termination was found to be 7.2 cm with a range of 3.8–11.8 cm. The mean diameter of the MEV at the mastoid emissary foramen was 3.5 mm with a range of 1.1–5.6 mm. In the majority of the cadavers (85%) it was observed that mastoid and occipital emissary veins formed a confluent venous system, while in the remaining 15%, they remained as single vessels. The MEV may be a significant source of bleeding during surgery of the skull base or middle ear, particularly during retrosigmoid and far-lateral approaches and detailed anatomical knowledge may help to prevent these complications. Endovascular treatment of dural arteriovenous fistulas is often extremely difficult due to limited access, however, the use of the MEV represents a unique and potentially valuable technique for accessing an isolated or inaccessible transverse or sigmoid sinus system. [ABSTRACT FROM AUTHOR]

We present the first clinical results from brain tissue imaging with a novel functionality in the angiography room, the XperCT. XperCT is a flat detector C-arm volume acquisition functionality integrated with the angiography equipment. We assessed brain images from 42 patients examined with computed tomography (CT) and XperCT. In all patients, XperCT had significantly more beam hardening and reconstruction artifacts than CT, in particular in the posterior fossa. Contrast resolution was better on CT images. Hemorrhage, edema, and ventricular size could be assessed with XperCT in all patients, but CT was superior also in this aspect. In four of the last 12 cases, after the latest software upgrade, it was possible to differentiate between supra-tentorial grey and white substance on XperCT images. CT was superior to XperCT regarding brain soft tissue imaging. However, XperCT could in some cases discriminate between grey and white substance. XperCT is a useful new functionality in interventional neuroradiology. In the clinical setting, it improves patient safety by allowing almost instant access to CT-like brain imaging in the angiography room. It can be life saving in situations where complications during an interventional procedure prompt for immediate action. [ABSTRACT FROM AUTHOR]

Carotid endarterectomy (CEA) is the goldstandard procedure for the majority of patients with high-grade symptomatic internal carotid artery stenosis and also for specified high-grade asymptomatic stenoses; however, a proportion of patients are treated with carotid endovascular therapy. We aimed to document medium-term clinical and neurosonographical outcome after carotid artery stenting (CAS). 53 patients (mean age: 65 ± 8 years) with high-grade (≥ 70 % by means of duplex sonography) carotid artery stenosis were enrolled into the study. Nineteen patients had asymptomatic, 34 patients had symptomatic stenoses. All patients had a pre-interventional CT, Doppler and duplex sonography, and digital subtraction angiography (DSA) or magnetic resonance angiography (MRA) prior to the procedural DSA. All patients were offered CEA as the gold-standard procedure and as an alternative to CAS. Both clinical and Duplex sonographical follow-up was obtained at day 1 and 7, month 1, month 3, month 6, month 12, and every subsequent 6 months after the procedure. Mean follow-up time was 22 ± 1.6 months (± SEM). 2/53 patients suffered from stroke. A further 2 patients suffered from carotid artery occlusion shortly after CAS. The cumulative rate of restenosis during follow-up was 24.5 % (13/53). Four of these (7.5 %) were of high-grade and led to further interventional or surgical therapy. A high rate of restenosis was found during follow-up after CAS. Our analysis of non-selected patients emphasizes that CEA remains the gold-standard procedure for the treatment of symptomatic internal carotid artery stenosis. The frequently performed endovascular treatment of carotid stenosis outside the setting of a randomized controlled trial is not supported by our data. [ABSTRACT FROM AUTHOR]

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Endovascular treatment of intracerebral wide-necked aneurysms carries the risk of incomplete embolisation and recanalisation of the aneurysm as well as coil protrusion into the parent artery and embolic complications. We present preliminary results with the placement of a novel tightly braided stent across the aneurysm neck which might lead to thrombosis of these aneurysms. A bifurcation artery aneurysm was created in a male New Zealand White Rabbit. After 4 weeks, a novel highly flexible stent with a central tightly braided mesh was placed across the aneurysm neck. Diagnostic angiography was performed during the procedure and immediately after stent deployment as well as 2 and 4 weeks following stent placement. Histological analyses, including microscopic investigations for evaluating intra-aneurysmal thrombosis and proliferation of the intima, were performed after 1 month. Intra-aneurysmal flow reduction due to stent placement was achieved as early as 45 min after deployment. Unchanged complete occlusion of the aneurysm could be observed by angiography 2 and 4 weeks post-stent deployment. Histological analysis confirmed angiographical findings of complete aneurysm occlusion and excluded significant neointimal coverage. This newly designed flexible stent may offer the potential to expand endovascular treatment of wide-necked intracranial aneurysms. [ABSTRACT FROM AUTHOR]

The occurrence of headaches during cerebral angiography or endovascular procedures is an ill-defined issue, as limited information is available to define its frequency, risk factors, pathogenesis and implications for future pain management. To determine the frequency of headaches during endovascular procedures (HdEVP) and to define their characteristics and risk factors for their occurrence. Prospective cross-sectional observational study of adult patients undertaking cerebral angiography or endovascular procedures, recording HdEVP clinical features, previous headache history and procedural variables. One hundred and twenty two procedures were evaluated. HdEVP occurred in 13 patients, both in diagnostic and therapeutic procedures. Pain was described as brief, stabbing or localized pressure of mild to moderate intensity, felt ipsilaterally to the manipulated vessel. Its occurrence was associated with therapeutic interventions (p = 0.007), female gender (p = 0.015) and previous history of more than 4 headache episodes per month (p = 0.018). HdEVP is an uncommon brief headache that should be further evaluated in the future. Its pathogenesis is probably related to mechanical vessel distension, which activates the trigeminovascular nociceptive system in susceptible individuals. [ABSTRACT FROM AUTHOR]

The magnetic navigation system consists of an externally generated magnetic field that is used to control and steer a magnetically tipped microguidewire. The goal of this study was to demonstrate that the use of the magnetic navigation system and its magnetic microguidewire is feasible and safe in all types of neuroendovascular procedures. A magnetic navigation system is an interventional workstation that combines a biplanar fluoroscopy system with a computer-controlled magnetic field generator to provide both visualization and control of a magnetically activated endovascular microguidewire. Ten consecutive patients underwent a variety of neuroendovascular procedures using the magnetic guidance system and magnetic microguidewire. All patients presented with a neurovascular disease that was suitable for endovascular treatment. Multiple different devices and embolic agents were used. Of the ten patients, three were male and seven female. Their mean age was 53.9 years. The predominant neurovascular condition was the presence of intracranial aneurysm (nine patients). One patient had a left mandibular arteriovenous malformation. All treatments were successfully performed on the magnetic navigation system suite. The magnetic navigation system and the magnetic microguidewire allowed safe and accurate endovascular navigation allowing placement of the microcatheters in the desired location. There were no neurological complications or death in our series. The use of the magnetic navigation system and the magnetic microguidewire in the endovascular treatment of patients with neurovascular diseases is feasible and safe. [ABSTRACT FROM AUTHOR]

The aim of the present study was to determine whether intracranial aneurysms are distended after coil embolization and to evaluate the distensibility of ruptured aneurysms treated with endovascular coiling. This was a prospective study of 20 consecutive patients with 22 aneurysms, who presented with a ruptured cerebral aneurysm and were treated with endovascular coiling of the aneurysm in a single institution. A diagnostic digital subtraction angiography (DSA) and a three-dimensional radiographic angiography (3DRA) were performed with bi-plane angiography equipment (Philips V5000) immediately before and after the embolization procedure to detect volume enlargement of the aneurysm after embolization, and the extent of the enlargement. A simulation study with steel spheres was carried out to study the possible error of over-estimation of the postembolization volume due to the beam-hardening artifact. There was no procedure-related rupture of the aneurysms. The percentage by volume of solid coil within the coil mass ranged from 15.78% to 82.01% in the present series. All aneurysms showed distension which ranged from 0.09% to 34.23%. The distensibility of the aneurysms was 34.23%. Error due to the beam-hardening artifact was negligible. Endoluminal packing of intracranial saccular aneurysms with embolization coils could cause a certain degree of distension in aneurysms treated with coil embolization, with the degree of distension up to 34.2%. Intracranial aneurysms were able to tolerate a certain degree of endoluminal distension without a risk of immediate rupture, even those that had ruptured recently. [ABSTRACT FROM AUTHOR]

Introduction: The use of n-butyl cyanoacrylate (NBCA) as an adhesive agent for embolization of high-flow intracranial and extracranial vascular lesions is well established. To be successful, the embolization of arteriovenous malformations and fistulas must achieve obliteration of the arteriovenous shunts themselves rather than simply occlude the feeders proximal to the lesion. However, the feeders cannot always be negotiated over their entire length. This is often the case with dural arteriovenous fistulas (DAVF), which are usually vascularized by long and intricate meningeal networks. In such situations, NBCA may not be able to reach the lesion itself, rendering the embolization ineffective. We present a new technique that improves distal distribution of NBCA glue. Methods: The technique described in this report consists of injecting dextrose 5% through the guiding catheter simultaneously with the superselective injection of NBCA glue into the targeted feeding branch. The technique is illustrated with three cases of posterior fossa DAVF. Results: In the reported cases, flooding the territory of the targeted vessel with non-ionic dextrose 5% allowed deep progression of the glue by delaying contact with ionic substances. Excellent distribution of the NBCA glue reaching the site of the arteriovenous shunts was thus obtained despite suboptimal proximal microcatheter tip positions. Conclusion: Simultaneous perfusion of dextrose 5% through the guiding catheter during NBCA injection dramatically improves the distal progression of glue through small, tortuous arterial feeders. This technique has the potential to increase the therapeutic value of transarterial embolization for DAVFs. [ABSTRACT FROM AUTHOR]

We present the first clinical results obtained with a novel technique: the three-dimensional [3D] roadmap. The major difference from the standard 2D digital roadmap technique is that the newly developed 3D roadmap is based on a rotational angiography acquisition technique with the two-dimensional [2D] fluoroscopic image as an overlay. Data required for an accurate superimposition of the previously acquired 3D reconstructed image on the interactively made 2D fluoroscopy image, in real time, are stored in the 3D workstation and constitute the calibration dataset. Both datasets are spatially aligned in real time; thus, the 3D image is accurately superimposed on the 2D fluoroscopic image regardless of any change in C-arm position or magnification. The principal advantage of the described roadmap method is that one contrast injection allows the C-arm to be positioned anywhere in the space and allows alterations in the distance between the x-ray tube and the image intensifier as well as changes in image magnification. In the clinical setting, the 3D roadmap facilitated intravascular neuronavigation with concurrent reduction of procedure time and use of contrast medium. [ABSTRACT FROM AUTHOR]

Recent advancements in endovascular aneurysm repair, including bioactive and expansile coils and intracranial stents, hold promise for improved aneurysm occlusion rates. We report the immediate and midterm clinical and angiographic outcomes of a consecutive series of patients treated since the advent of these technologies. Clinical and radiological records of 134 patients with 142 aneurysms treated between 2001 and 2004 were retrospectively evaluated by an independent neurologist. Endovascular procedures were analyzed by an independent neuroradiologist blinded to all clinical information. Seventy-two ruptured and 60 un-ruptured saccular aneurysms, nine fusiform and one post-traumatic aneurysm were treated. Matrix coils were used in 53% of saccular aneurysms and HydroCoils in 13% of all aneurysms. Neuroform stents were deployed in 19% of aneurysms. Angiographic total or subtotal occlusion was achieved in 76% of cases and in 96% at last follow-up. Aneurysm recanalization was observed in 14% over a mean follow-up of 12 months, and 18% of aneurysms were retreated. Clinically relevant complications occurred in 6.0%, resulting in procedure-related morbidity of 0.6% and 0.6% mortality at 6 months. No aneurysm bled over a cumulative 1,347 months of observation. Newer embolization technologies can be exploited successfully even in more complex aneurysms with very low morbidity and mortality. [ABSTRACT FROM AUTHOR]

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