Thrombectomy in ischemic stroke patients with alberta stroke program early computed tomography score 4-5 and 0-3: Factors associated with favorable outcome.

OBJECTIVES: Recently published results of the ANGEL-ASPECT and SELECT2 trials suggest that stroke patients presenting with low Alberta Stroke Program Early Computed Tomography Score (ASPECTS) benefit from mechanical thrombectomy. Purpose of this retrospective study was to identify factors that are associated with a favorable outcome in patients with low ASPECTS of 4-5 and 0-3 undergoing mechanical thrombectomy. MATERIAL AND METHODS: All patients reported in the quality registry of the German Society for Neuroradiology that were treated between 2018 and 2020 were analyzed. Favorable outcome was defined as a National Institute of Health Stroke Scale (NIHSS) score of less than 9 at dismissal. Successful recanalization was defined as Thrombolysis in Cerebral Infarction (mTICI) ≥ 2b. Multivariable logistic regression analyses were performed to assess the association of baseline and treatment variables with favorable outcome. RESULTS: 621 patients were included in the analysis, thereof 495 with ASPECTS 4-5 and 126 with ASPECTS 0-3. In patients with ASPECTS 4-5patients with favorable outcome had less severe neurological symptoms at admission with median NIHSS of 15 vs. 18 (p<0.001), had less often wake-up strokes (44% vs. 81%, p<0.001), received more often iv-lysis (37% vs. 30%, p<0.001), had more often conscious sedation (29% vs. 16%, p<0.001), had a higher rate of successful recanalization (94% vs. 66% and lower times from groin puncture to recanalization. In multivariate regression analysis lower NIHSS at admission (aOR 0.87, CI 0.89-0.91) and successful recanalization (aOR 3.96, CI 2-8.56) were associated with favorable outcome. For ASPECTS 0-3, patients with favorable outcome had lower median NIHSS at admission (16 vs. 18 (p<0.001), lower number of passes (1 vs. 3, p=0.003) and a higher rate of successful recanalization (94% vs. 66%, p<0.001) and lower times from groin puncture to recanalization. In multivariate regression analysis lower NIHSS at admission (aOR 0.87, CI 0.81-0.94) and successful recanalization, (aOR 11.19, CI 3.19-55.53), were associated with favorable outcome. CONCLUSION: Full recanalization with low groin punction to recanalization times and low number of passes were associated with favorable outcome in patients with low ASPECTS.

[Ischemic stroke in coronavirus disease 2019]. / Ischämische Hirninfarkte bei Coronavirus-19-Erkrankung.

This article reports two cases of patients with coronavirus disease 2019 (COVID-19) in which occlusion of large cerebral arteries occurred. These occurred in a female patient in the early stage of COVID-19 and in the second case in the late stage. One female patient could be successfully treated with i.v. thrombolysis and mechanical thrombectomy. Coagulopathy in the course of COVID-19 can result in severe stroke with poor outcome even in younger patients. With respect to the etiology of arterial occlusions (COVID-19-induced hypercoagulopathy, cardiomyopathy, vasculitis) there is a necessity for further research.

ERASER.

Background and Purpose- Using a novel study design with virtual comparators based on predictive modeling, we investigated whether next-generation mechanical thrombectomy devices improve outcomes in patients with ischemic stroke. We hypothesized that this new study design shows that a next-generation mechanical thrombectomy system is superior to intravenous tPA (tissue-type plasminogen activator) therapy (IVT) alone. Methods- ERASER (Eric Acute Stroke Recanalization) was an investigator-initiated, prospective, multicenter, single-arm (virtual 2-arm) study that evaluated the effectiveness of a new recanalization device together with a specific intermediate catheter (Embolus Retriever with Interlinked Cages/SOFIA, Microvention) in stroke patients with internal carotid artery or middle cerebral artery occlusions. The primary end point was the volume of saved tissue. Volume of saved tissue was defined as the difference of actual infarct volume and brain volume predicted to develop infarction using a machine learning model based on data from intravenous tPA therapy patients. Results- Eighty-one patients were enrolled. The median patient age was 71 years (interquartile range, 61-77). National Institutes of Health Stroke Scale score was 14 (interquartile range, 12-18). The actual infarct volume was smaller than predicted by the intravenous tPA therapy model, with a median volume of saved tissue of 50 mL (interquartile range, 19-103; P<0.0001). Good clinical outcome (modified Rankin Scale, 0-2 at 90 days) was observed in 48 out of 69 (70%). The recanalization rate (Thrombolysis in Cerebral Infarction 2b/3) was 95%. Conclusions- ERASER is the first mechanical thrombectomy study with a primary end point based on predictive analytics enabling intraindividual virtual comparisons. The next-generation mechanical thrombectomy method resulted in smaller infarcts than predicted after intravenous tPA therapy alone and showed a high rate of good clinical outcome. The novel study design with virtual comparisons is promising for further application and testing in the neurovascular arena. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT02534701.

Effect of General Anaesthesia versus Conscious Sedation on Clinical and Procedural Outcome in Patients Undergoing Endovascular Stroke Treatment: A Matched-Pair Analysis.

INTRODUCTION: General anaesthesia (GA) during mechanical thrombectomy (MT) might lead to an inferior clinical outcome compared to conscious sedation (CS). It was hypothesised that using CS might avoid a critical drop in cerebral perfusion, shorten the time of the intervention and therefore might result in better clinical outcome. In this study, we compared the procedural and clinical results of patients who underwent MT under GA or CS at two tertiary neuro-vascular centres on the basis of a matched-pair analysis. METHODS: Using a matched-pair approach, we compared the data of 56 patients that were treated under CS at centre A (n = 28) with selected patients who were treated under GA at the centre B (n = 28). Patients were matched for age, sex, site of vessel occlusion, NIHSS at admission (±3 points), time from symptom onset to initial stroke imaging, intravenous-lysis and co-morbidities. All patients had an ASPECT-score of ≥8. To exclude the effect of technical failures, only patients with successful recanalization of the occluded vessel (TICI 2b and 3) were included into the study. The primary endpoint was the proportion of patients with early good clinical outcome after MT, defined by a modified Ranking Scale (mRS)-score ≤2 at discharge. Secondary endpoints were the time from symptom onset to the start of the procedure, the duration of the procedure and the rate of procedural complications. RESULTS: There were no differences concerning gender, age, the site of vessel occlusion and the degree of stroke severity at baseline. The proportion of patients with an early good clinical outcome (mRS ≤2 at discharge) was 60.4% (17/28) in both groups. The time from symptom onset to the start of the procedure was shorter at centre B, while the duration of the procedure was significantly faster at A, resulting in an overall time from symptom onset to complete recanalization of 152.2 ± 68.0 min for patients treated at centre A and 171.1 ± 43.5 min for patients at centre B (ns). CONCLUSION: Our study revealed no differences in the investigated clinical outcome for patients undergoing endovascular stroke treatment under GA versus CS.

[Precision and safety of positioning pedicle screws in the thoracic and lumbar spine using a hand-guided aiming sleeve : A CT control study]. / Präzision und Sicherheit der Positionierung von Pedikelschrauben in der Brust- und Lendenwirbelsäule mittels handgeführter Zielhülse : Eine computertomographische Kontrollstudie.

BACKGROUND: For the implantation of pedicle screws, navigation-supported systems are nowadays used more and more to avoid screw misalignment by making the direction of the screw more predictable. OBJECTIVE: Examination of the precision after instrumentation of the pedicle screw with the hand-guided aiming sleeve. The aim was to verify that the implementation of the pedicle screws is plannable and precise by using 2D X­ray only. METHOD: This retrospective study analyzed 27 consecutive trauma patients (17-84 years, 13f/14m) with vertebral body fractures. The position and precision of 108 screws, implanted using the hand-guided aiming sleeve was investigated. To determine the position the actual course of the screws was examined using the postoperative 3D CT data set (GE Optima 540, General Electric Company Boston, MA, USA; slice thickness 1.25 mm). The screws were then compared to the previously defined ideal position of the tip of the screw. In addition to the absolute and relative deviation from the ideal target point, the convergence angle and the parallelism to the cover plate were determined. RESULTS: Of 108 implanted pedicle screws, 90 (83%) were within target. The remaining 18 (17%) represented a clinically irrelevant screw deviation: A lateral deviation was found in 17 pedicle screws (16%) and a medial deviation in 1 (1%). The average deviation from the ideal target point in the vertebral body was 2.3 mm ventrally with a standard deviation of ±â€¯2.3 mm. No screw misalignment or pedicle perforation was found. CONCLUSION: The transcutaneous implantation of pedicle screws with a hand-guided aiming sleeve in the thoracic and lumbar spine represents a safe and precise procedure. The risk of misalignment needing a revision is lower compared to other methods of navigated screw implantation reported in the literature [1-6]. A CT-based preliminary planning is not necessary. The method is economical, special technical equipment is not required.

The status of academic interventional radiologists in Germany with focus on gender disparity: how can we do better?

PURPOSE: The aim was to characterize the framework conditions in academic interventional radiology (IR) in Germany with focus on differences between genders. MATERIALS AND METHODS: After IRB approval, all members of The German Society for Interventional Radiology and Minimally Invasive Therapy (n = 1,632) were invited to an online survey on work and research. Statistical comparisons were undertaken with the Fisher's exact test, Wilcoxon rank sum test or Pearson's Chi-squared test. RESULTS: From 267 available questionnaires (general response rate 16.4%), 200 were fully completed. 40% of these (78/200) were involved in research (71% men vs. 29% women, p < 0.01) and eligible for further analysis. Of these, 6% worked part-time (2% vs. 17%, p < 0.05). 90% of the respondents spent less than 25% of their research during their paid working hours, and 41% performed more than 75% of their research during. leisure time. 28% received exemption for research. 88% were (rather) satisfied with their career. One in two participants successfully applied for funding, with higher success rates among male applicants (90% vs. 75%) and respondents with protected research time (93% vs. 80%). Compared to men, women rated their entrance in research as harder (p < 0.05), their research career as more important (p < 0.05), felt less noticed at congresses (93% vs. 53%, p < 0.01), less confident (98% vs. 71%, p < 0.01), and not well connected (77% vs. 36%, p < 0.01).  CONCLUSION: Women and men did research under the same circumstances; however, women were underrepresented. Future programs should generally focus on protected research time and gather female mentors to advance academic IR in Germany.

Endovascular stroke therapy: tirofiban is associated with risk of fatal intracerebral hemorrhage and poor outcome.

BACKGROUND AND PURPOSE: To investigate the relationship between severe bleeding complications and outcome after mechanical thrombectomy with or without glycoprotein-IIb/IIIa inhibitor tirofiban treatment. METHODS: The study included prospectively collected data of consecutive patients with acute ischemic stroke in whom mechanical thrombectomy was perfomed in the years 2006 to 2011. RESULTS: Of 162 patients, 128 patients had anterior circulation stroke, and 34 patients had posterior circulation stroke. Additional treatment with tirofiban was given to 30 of 128 patients with anterior circulation stroke and to 20 of 34 patients with posterior circulation stroke. Treatment with tirofiban did not influence recanalization rates. Fatal intracerebral hemorrhage occurred more frequently in tirofiban-treated patients in the entire cohort (12.0% vs 2.7%; P=0.03) and in tirofiban-treated patients with anterior circulation stroke (13.3% vs 3.1%; P=0.05). Logistic regression found age (odds ratio, 1.17; 95% confidence interval, 1.00-1.37; P=0.05) and tirofiban treatment (odds ratio, 3.03; 95% confidence interval, 1.50-4.05; P=0.04) to be independent predictors for fatal intracerebral hemorrhage. Tirofiban treatment was also an independent predictor for poor outcome (odds ratio, 6.60; 95% confidence interval, 1.06-41.52; P=0.04) in addition to National Institute of Health Stroke Scale (odds ratio, 1.08; 95% confidence interval, 1.00-1.17; P=0.05). CONCLUSIONS: In endovascular stroke therapy, additional treatment with the glycoprotein-IIb/IIIa inhibitor tirofiban is associated with increased risk of fatal intracerebral hemorrhage and poor outcome.

Spot signs in intracerebral hemorrhage: useful for identifying patients at risk for hematoma enlargement?

BACKGROUND: Prognostic signs for the identification of patients with acute spontaneous intracerebral hemorrhage (SICH) prone to hematoma expansion are limited. Contrast extravasation (spot signs, SpS) on computed tomographic angiography (CTA) may be a promising method to predict hematoma expansion in acute SICH. However, prospective data on the predictive value of the SpS on hematoma expansion and clinical outcome are still limited. We aimed to investigate associations between the presence of SpS, hematoma expansion, and clinical outcome in acute SICH. METHODS: A prospective observational study was performed between 08/2008 and 08/2011. Patients with SICH presenting within 6 h of symptom onset were included. Patients with secondary hematomas, purely intraventricular hematomas, incomplete CT evaluation, hematoma evacuation prior to follow-up brain imaging, and incomplete follow-up data and those who refused to give consent for data analysis were excluded. CT and CTA brain imaging were carried out in all patients at baseline. After 24 h, follow-up brain imaging was performed. Hematoma location, hematoma volume, and substantial hematoma expansion were documented. CTA images were evaluated by two investigators for the presence of SpS. In all positive SpS cases, images were additionally reviewed by a third rater to achieve consensus for interpretating contrast extravasation. Clinical outcome was measured by the modified Rankin Scale (mRS) at discharge and at 3 months. RESULTS: In total, 101 patients [median age 73 years (interquartile range 60-79); male 61.4%] were included in the analysis. Median time from onset to CTA was 128 min (interquartile range 90-209 min); median initial National Institute of Health Stroke Scale score was 16 (8-21). SpS were detected in 27 patients (26.7%). Cohen's kappa for the presence of SpS was 0.606, indicating moderate agreement. SpS patients had significantly higher initial hematoma volumes than patients without SpS (36.0 vs. 14.39 ml, p = 0.005). Hematoma expansion was significantly more frequent in SpS patients (59.3 vs. 21.6%, p < 0.001) and associated with the presence of SpS in the univariate analysis (OR 5.273; 95% CI 2.047-13.584, p = 0.001) and in multivariable analysis adjusted for the initial hematoma volume (OR 4.678, 95% CI 1.781-12.288, p = 0.002). Sensitivity of SpS to predict hematoma expansion was 0.5, specificity was 0.84. The positive likelihood ratio for SpS to predict hematoma expansion was 3.136 (95% CI 1.649-5.967), the negative likelihood ratio was 0.595 (95% CI 0.414-0.854). No difference in 3-month clinical outcome was observed between patients with and without SpS (median mRS score 4 and 4, p = 0.457). CONCLUSIONS: The clinical value of SpS needs to be further explored. Future studies should particularly focus on structured training procedures to identify SpS and measure the time needed to precisely assess the presence of SpS and on the prevalence of SpS in consecutive intracerebral hemorrhage populations.

Radiation Exposure in Interventional Stroke Treatment : Analysis of the German Neurointerventional Database (DeGIR/DGNR) from 2019 to 2021.

PURPOSE: To evaluate patient-related radiation exposure in interventional stroke treatment by analyzing data from the German Society for Interventional Radiology and Minimally Invasive Therapy (DeGIR) and the German Society of Neuroradiology (DGNR) quality registry from 2019-2021. METHODS: The DeGIR/DGNR registry is the largest database of radiological interventions in Germany. Since the introduction of the registry in 2012, the participating hospitals have entered clinical and dose-related data on the procedures performed. To evaluate the current diagnostic reference level (DRL) for mechanical thrombectomy (MT) in stroke patients, we analyzed interventional data from 2019 to 2021 with respect to the reported dose area product (DAP) and factors that might contribute to the radiation dose, such as the localization of the occlusion, technical success using the modified treatment in cerebral ischemia (mTICI) score, number of passages, technical approach, additional intracranial/extracranial stenting, and case volume per center. RESULTS: A total of 41,538 performed MTs from 180 participating hospitals were analyzed. The median DAP for MT was 7337.5 cGy∙cm2 and the corresponding interquartile range (IQR) Q25 = 4064 cGy∙cm2 to Q75 = 12,263 cGy∙cm2. In addition, we discovered that the dose was significantly influenced by occlusion location, number of passages, case volume per center, recanalization score, and additional stenting. CONCLUSION: We conducted a retrospective study on radiation exposure during MT in Germany. Based on the results of more than 41,000 procedures, we observed that the DRL of 14,000 cGy·cm2 is currently appropriate but may be lowered over the next years. Furthermore, we identified several factors that contribute to high radiation exposure. This can aid in detecting the cause of an exceeded DRL and optimize the treatment workflow.

Results of interventional treatment of peripheral slow-flow malformations.

BACKGROUND: In recent years sclerotherapy has increasingly become the treatment of choice for peripheral slow-flow malformations. However, the long-term effectiveness of sclerotherapy is still a matter of debate, especially when it comes to new sclerosing agents like polidocanol. This study aims at gathering further information concerning its long-term effectiveness and safety. RESULTS: Most patients reported a reduction of symptoms which include pain (57,7%), swelling (65,4%) and functional impairment (60%). Cosmetic complaints were less likely to be reduced by sclerotherapy (44,4%). In most cases a relief of symptoms was stable for many years, especially after several consecutive treatment sessions. Complication rates were comparably low, with only 2 patients requiring additional treatment at hospital and no lasting damages. (…) (7) Most patients (70,9%) were at least partially satisfied with the treatment. Satisfaction was closely linked to a partial or complete relief of symptoms (p = 0.001). CONCLUSION: Sclerotherapy is a promising way of treating slow-flow-malformations. Polidocanol has proved to be a save sclerosing agent. The reduction of major symptoms was substantial in most cases and lasted for many years.

Subarachnoid hemorrhages and aneurysms during the SARS-CoV2-pandemia at a tertiary medical center - Analysis of incidence and outcome.

Introduction: During the COVID-19-pandemic a significant decrease of up to 13% of all kinds of medical emergencies was reported. Similar trends were expected for aneurysmal subarachnoid hemorrhages (aSAH) and/or symptomatic aneurysms. Research question: To analyze a correlation of the SARS-CoV2-infection and the incidence of aSAH, and to assess the impact of the pandemic-lockdown on the incidence, the outcome and the course of patients suffering from aSAH and/or aneurysms. Material and methods: From March 16th, 2020 (first lockdown in Germany) to January 31st, 2021, all patients admitted to our hospital were screened by polymerase-chain-reaction (PCR) test for genetic material of SARS-CoV2. During this period, aSAH and symptomatic cerebral aneurysms were assessed and retrospectively compared to a historic longitudinal case-cohort. Results: Of 109.927 PCR-tests, 7.856 (7.15%) revealed a SARS-CoV2-infection. None of the patients mentioned above were tested positively. The number of aSAH and symptomatic aneurysms rose by 20.5% (39 vs. 47 cases) (p â€‹= â€‹0.93). Poor grade aSAH, as well as extensive bleeding-patterns were more often observed (p â€‹= â€‹0.63 and p â€‹= â€‹0.40, respectively), with more symptomatic vasospasms diagnosed (5 vs. 9 patients). Mortality rate increased by 8,4%. Discussion and conclusion: A correlation between SARS-CoV2-infection and the incidence of aSAH could not be established. Still, the overall number and the number of poor-grade aSAHs increased as well as symptomatic aneurysms during the pandemic. Therefore, we might conclude that dedicated neurovascular competence should be retained in designated centers to care for these patients even or especially in special situations affecting the global healthcare system.

Outcome prediction prior to thrombectomy of the posterior circulation with machine learning.

PURPOSE: Various studies have identified prognostic factors for a favorable outcome of endovascular treatment in posterior circulation. We evaluated various machine learning algorithms in their ability to classify between patients with favorable (defined as 0-2 points on the modified Rankin scale [mRS]), unfavorable (mRS 3-6), poor (mRS 5-6), and nonpoor (mRS 0-4) outcomes at dismissal. METHODS: We retrospectively analyzed data from 415 patients that were treated between 2018 and 2021 from the multicentric DGNR registry. Five models (random forest, support vector machine, k-nearest neighbor, neural network [NN], and generalized linear model [GLM]) were trained with clinical input variables and evaluated with a test dataset of 82 patients. The model with the highest accuracy on the training dataset was defined as the best model. RESULTS: A total of 132 patients showed poor and 162 patients showed favorable outcome. All baseline variables except sex were highly significantly different between patients with favorable and unfavorable outcomes. The variables NIHSS, the presence of wake-up stroke, the administration of IV-thrombolysis and mRS pretreatment were significantly different between patients with poor and nonpoor outcomes. The best-performing NN achieved a sensitivity of 0.56, a specificity of 0.86 and an area under the curve (AUC) of 0.77 on the test dataset in the classification analysis between favorable and unfavorable outcomes. The best-performing GLM achieved a sensitivity of 0.65, a specificity of 0.91 and an AUC of 0.81 in the classification analysis between poor and nonpoor outcomes. CONCLUSION: Short-term favorable and poor outcomes in patients with acute ischemic stroke of the posterior circulation can be predicted prior to thrombectomy with moderate sensitivity and high specificity with machine learning models.

Thrombectomy of Mild Stroke : An Analysis of the Nationwide Registry of the German Society for Neuroradiology.

PURPOSE: Whether patients presenting with mild stroke (NIHSS at admission < 6) should be treated with mechanical thrombectomy (MT) is the subject of an ongoing debate. This retrospective study based on large-scale clinical data aims to identify factors associated with favorable outcome (FO) in patients with mild stroke. METHODS: A total of 761 patients with mild stroke enrolled between 1 January 2020 and 31 December 2020 in the Quality Registry of the German Society for Neuroradiology were analyzed. The FO was defined as stable or improved NIHSS at discharge vs. admission. Descriptive statistics and multivariable logistic regression analyses were performed to identify factors associated with FO. Furthermore, a subgroup analysis of mild stroke based on distal vessel occlusion was conducted. RESULTS: In this study 610 patients had FO with a median NIHSS at discharge of 1 (interquartile range, IQR, 0-2) and 151 had an unfavorable outcome (UO) with median NIHSS at discharge of 10 (IQR 13). Patients with FO had a slightly higher NIHSS at admission (4 vs. 3, p < 0.001), lower mTICI 0 (2.7% vs. 14.2%, p < 0.001), higher mTICI 3 (61.3% vs. 34.5%, p < 0.001) and a lower number of passes (1 vs. 2, p < 0.001). No statistically significant difference was observed for MT-related adverse events. Multivariable logistic regression suggested that NIHSS at admission (adjusted odds ratio (aOR) = 1.28, 95% confidence interval (CI) = 1.10-1.48), mTICI 2b (aOR = 5.44, CI = 2.06-15.03), mTICI 2c (aOR = 10.81, CI = 3.65-34.07) and mTICI 3 (aOR = 11.56, CI = 4.49-31.10) as well as number of passes (aOR 0.76, CI = 0.66-0.88) were significantly associated with FO. No MT-related adverse events were observed for distal vessel occlusions. CONCLUSION: The FO in patients with mild stroke undergoing MT was associated with successful recanalization. No significant differences between patients with FO and UO were found for MT-related adverse events, suggesting that MT complications have no significant effects on the outcome of these patients. MT might improve the prognosis also in patients with mild stroke based on distal vessel occlusions without significantly increasing the risk of adverse events.

Herpes simplex virus encephalitis despite normal cell count in the cerebrospinal fluid.

OBJECTIVES: To describe herpes simplex virus encephalitis despite normal cell count in the cerebrospinal fluid in patients with malignoma after whole brain irradiation. INTERVENTIONS: Blood and cerebrospinal fluid analysis and magnetic resonance imaging. MEASUREMENTS AND MAIN RESULTS: Three male and two female patients with malignoma and a recent history of whole-brain irradiation presented with impaired consciousness with or without epileptic seizure. Although cerebrospinal fluid analysis revealed a normal cell count, herpes simplex virus DNA was detected in all samples by polymerase chain reaction. CONCLUSIONS: In patients with impaired consciousness, epileptic seizure, or temporal lobe symptoms of new onset and a recent history of brain irradiation with normal cerebrospinal fluid, an atypical anergic course of herpes simplex virus encephalitis should be considered. Herpes simplex virus polymerase chain reaction should be used as method of choice to detect herpes simplex virus genomes as early as possible rather than relying on routine cerebrospinal fluid parameters. Importantly, antiviral therapy should be started without delay in any case of faint suspicion and should be continued until herpes simplex virus encephalitis is clearly ruled out.

Fast-track intubation for accelerated interventional stroke treatment.

BACKGROUND: As intravenous thrombolysis frequently fails to recanalize occluded proximal intracerebral arteries, interventional recanalization therapy is increasingly being considered as treatment option in acute ischemic stroke patients. The optimal periprocedural patient management for these interventions is currently unknown. The aim of this study was to identify factors delaying door-to-treatment times, and to evaluate the effect of a fast-track intubation standard operating procedure (I-SOP) on door-to-angiography time. METHODS: First, we retrospectively reviewed records of 48 acute stroke patients who were treated by interventional recanalization of intracranial occlusions between 2006 and 2009 at our institution. Time to angiography was defined as time from hospital admission to the beginning of the angiographic procedure. Second, an I-SOP for fast-track intubation was implemented and effects on door-to-angiography time were prospectively analyzed in 23 consecutive patients. RESULTS: In the retrospective dataset (n = 48), the mean door-to-angiography time was 2.2 ± 0.1 h (mean ± SEM). A clinically relevant time loss attributable to the intubation procedure was suggested by a 51 ± 21 min shorter door-to-angiography time for patients already intubated prior to admission (P = 0.0189). Additional factors associated with a prolonged door-to-angiography time were: door-to-diagnosis time (P < 0.001), onset-to-door time (P = 0.0117), and male gender (mean difference +27 ± 15 min, P = 0.0822). In the prospective dataset (n = 23), I-SOP implementation reduced mean door-to-angiography time by 25 ± 10 min (P = 0.0164). CONCLUSIONS: In acute stroke patients, intubation prior to interventional recanalization therapy can delay treatment initiation. The implementation of an I-SOP accelerates interventional treatment initiation.

Treatment of acute ischemic stroke with clot retrieval devices.

OPINION STATEMENT: Mechanical clot retrieval is increasingly used for flow-restoration and thrombectomy in acute embolic stroke. Emerging as a treatment option in addition to intravenous or intra-arterial thrombolysis, it is currently being further developed and investigated as a potential first-line and stand-alone treatment. The ability to rapidly restore flow and effectively retrieve clots from large intracranial arteries is reflected by angiographic data and preliminary clinical results. This article reviews the principles and technical aspects of this new technique, its emergence from the spectrum of intravenous and endovascular stroke treatment, and summarizes the first clinical results for acute ischemic anterior and posterior circulation stroke. Clot retrieval devices are a very promising option for treatment of acute ischemic stroke in the setting of large vessel occlusion. However, there currently exists a reported discrepancy between excellent recanalization rates and less satisfactory clinical outcomes. This problem urgently needs to be addressed in a prospective randomized fashion and improvements of treatment be recognized and implemented before clot retrieval can be considered an established form of acute stroke treatment.

[Artificial intelligence in orthopaedic and trauma surgery imaging]. / Künstliche Intelligenz in der orthopädisch-unfallchirurgischen Radiologie.

Artificial intelligence (AI) is playing an increasing role in radiological imaging in orthopaedics and trauma surgery. The algorithms available to date are predominantly used in the detection of (occult) fractures and in length and angle measurements in conventional X­ray images. However, current AI solutions also enable the analysis and pattern recognition of CT datasets, e.g. in the detection of rib or vertebral body fractures. A special application is EOS™ (ATEC Spine Group, Paris, France), which enables a 3­D simulation of the axial skeleton and semi-automatic length and angle calculations based on a digital 2­D X­ray image. In this paper, the current spectrum of AI applications for orthopaedics and trauma surgery is presented and discussed.

Non-ischemic neurovascular emergencies at a supra-regional medical center during the SARS-CoV2-pandemia.

OBJECTIVE: To assess the impact of the lockdown in Germany due to the SARS-CoV2-pandemic on the incidence and the outcome of neurovascular emergencies at a tertiary medical center. METHODS: From March 16th, 2020 (first lockdown in Germany) to January 31st, 2021, all neurosurgical emergencies were included and compared to a longitudinal case-cohort. Cases were descriptively recorded and retrospectively analyzed with respect to incidence and outcome. RESULTS: All emergencies referred to our tertiary medical center decreased by 10% during the pandemic, whereas, neurosurgical emergencies increased by 18.4% (764 vs. 905 cases). Number of specific non-ischemic neurovascular emergencies increased by 29% (95 vs. 123 cases). The difference was not statistically significant (p = 0.53). Mortality rate increased dramatically by 40% during the pandemic throughout all neurovascular cases. As all included patients were negative PCR-tested for SARS-CoV2 the observed increase is unrelated to the virus infection. CONCLUSION: Unexpectedly, according to our data neurovascular emergencies raised in number and severity during the pandemic in Germany at our tertiary referral center. Furthermore, the case fatality increased. Even though our data lack proof of evidence for these findings, we might suggest two possible explanations for the absolute increase in numbers: firstly, patients might have refused to seek medical help while suffering only mild symptoms. Furthermore, as numerous lower-level medical centers restricted admissions, the referral times of patients in need of neurosurgical attention increased. We, therefore, suggest that even in a pandemic situation like the SARS-CoV2/COVID-19, it seems of utmost importance to retain dedicated neurovascular competence in designated centers to care for these emergencies.

Clinical evaluation of a novel head protection system for interventional radiologists.

PURPOSE: A novel two-part protective system consisting of a modified thyroid collar and a head protection is intended to reduce the radiation dose to the examiners head during fluoroscopy-guided interventions. In this pilot study, we tested this protection system under real-life conditions in general radiological and neuroradiological interventions. METHODS: Two sets of the protection system (set A and B) were equipped with 12 thermoluminiscence detectors (TLD). For simultaneous measurement of radiation exposure and dose-reduction, each six TLDs were fixed to the inner side and on the corresponding outer side of the protection system. Set A was used exclusively for general radiological interventions and set B exclusively for neuroradiological interventions. To compare the staff exposure in general radiology and neuroradiology, dose values were normalized to a DAP of 10 000 µGy∙m2. RESULTS: The sets were tested during 20 general radiological interventions and 32 neuroradiological interventions. In neuroradiology, the mean normalized radiation exposure was 13.44 ± 1.36 µSv/10000 µGy∙m2 at the head protection and 22.27 ± 2.09 µSv/10 000 µGy∙m2 at the thyroid collar. In general radiology, the corresponding results were 29.91 ± 4.19 µSv/10 000 µGy∙m2 (head protection) and 68.07 ± 17.25 µSv/10 000 µGy∙m2 (thyroid collar). Thus, mean dose exposure was 2.5 times higher in general radiological interventions (p = 0.016). The use of the protection system resulted in a mean dose reduction of 81.2 ± 11.1 % (general radiology) and 92.1 ± 4.2 % (neuroradiology; p = 0.016). CONCLUSION: Fluoroscopy-guided interventions lead to significant radiation exposure of the head area for the examiner. The novel protection system tested led to a significant dose reduction of 80-90%, depending on the type of intervention.

Machine learning based outcome prediction of large vessel occlusion of the anterior circulation prior to thrombectomy in patients with wake-up stroke.

PURPOSE: Outcome prediction of large vessel occlusion of the anterior circulation in patients with wake-up stroke is important to identify patients that will benefit from thrombectomy. Currently, mismatch concepts that require MRI or CT-Perfusion (CTP) are recommended to identify these patients. We evaluated machine learning algorithms in their ability to discriminate between patients with favorable (defined as a modified Rankin Scale (mRS) score of 0-2) and unfavorable (mRS 3-6) outcome and between patients with poor (mRS5-6) and non-poor (mRS 0-4) outcome. METHODS: Data of 8395 patients that were treated between 2018 and 2020 from the nationwide registry of the German Society for Neuroradiology was retrospectively analyzed. Five models were trained with clinical variables and Alberta Stroke Program Early CT Score (ASPECTS). The model with the highest accuracy was validated with a test dataset with known stroke onset and with a test dataset that consisted only of wake-up strokes. RESULTS: 2419 patients showed poor and 3310 patients showed favorable outcome. The best performing Random Forest model achieved a sensitivity of 0.65, a specificity of 0.81 and an AUC of 0.79 on the test dataset of patients with wake-up stroke in the classification analysis between favorable and unfavorable outcome and a sensitivity of 0.42, a specificity of 0.83 and an AUC of 0.72 in the classification analysis between poor and non-poor outcome. CONCLUSION: Machine learning algorithms have the potential to aid in the decision making for thrombectomy in patients with wake-up stroke especially in hospitals, where emergency CTP or MRI imaging is not available.