Research Presentation Session: Neuro

RPS 711 - Stroke: treatment and outcome

February 29, 08:00 - 09:00 CET

7 min
Cost-effectiveness of mobile stroke units in Germany: a perspective on catchment areas, operating modes, and staffing
Fabian Tollens, Mannheim / Germany
Author Block: F. Tollens, C. Hoyer, K. Szabo, J. Rink; Mannheim/DE
Purpose: Estimating the cost-effectiveness of future mobile stroke unit (MSU) services with respect to local idiosyncrasies is essential for optimising major program determinants and enabling large-scale implementation of MSU services. Therefore, the aim of this study was to assess the cost-effectiveness of MSU services for varying urban German settings.
Methods or Background: Costs of different operating modes and hours including weekend and non-weekend coverage, including different personnel configurations, were simulated for the German healthcare system. Ischaemic stroke incidence, circadian distribution, rates of alternative diagnoses and stroke mimics, as well as missed cases, were incorporated to model case coverage and patient-level costs of acute stroke care. Based on internationally reported stroke outcomes, a five-year Markov Model was applied to analyse the cost-effectiveness outcomes for varying catchment zone populations.
Results or Findings: Compared to regular emergency medical services, stroke care by MSU achieved additional 0.06 QALYs on average over a five-year time horizon. Assuming a catchment zone of 400,000 inhabitants and 12 hour/ seven day coverage resulted in an incremental cost-effectiveness ratio (ICER) of €42,069 per QALY gained. Lower ICERs were possible when coverage was expanded to 16 hour-service on 7 days per week. Sensitivity analyses revealed that the population size within the catchment zones and the number of ischaemic strokes missed by MSU deteriorated economic performance of MSU significantly.
Conclusion: Major determinants of cost-effectiveness should be addressed when setting up novel MSU programs. For the German healthcare system, the catchment zone should cover at least 400,000 inhabitants and MSU service should cover 12-16 hours per day, including weekends.
Limitations: This study used a model-based economic evaluation of MSU program costs and stroke case estimates.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: There was no ethical approval necessary as no human data was analysed.
7 min
Set-up and planning of a MSU service in a medium-sized German urban area
Johann S Rink, Mannheim / Germany
Author Block: F. Tollens, J. Rink, C. Hoyer, K. Szabo; Mannheim/DE
Purpose: Mobile stroke units (MSU) equipped with mobile CT scanners have demonstrated major improvements in prehospital stroke care. Due to the geographical, social, and structural characteristics of the German city of Mannheim within the Rhine-Neckar Metropolitan Region, concepts of previously established MSU services cannot directly be transferred to Mannheim. The present analysis aimed to identify major determinants that need to be considered when setting up an MSU service in Mannheim.
Methods or Background: Program costs consisting of hardware investments, CT scanner and contrast media injector, personnel, and project management were estimated based on hospital accounting and vendors. Local stroke statistics from 2015 to 2021 were analysed to calculate the circadian distribution of strokes and local incidence rates. Future MSU patient numbers and program costs were analysed for varying operating modes, daytime coverage models, and staffing configurations. Case coverage and economic determinants were assessed in sensitivity analyses.
Results or Findings: 54.3% of all stroke patients were admitted during a ten-hour time window on weekdays. When assuming that about half of all incident stroke patients did not call the emergency centre or were missed at dispatch, an average of 0.8 stroke patients could be expected in a 10-hour shift each day in Mannheim, which could potentially be increased by expanding the catchment area. Overall estimated MSU costs amounted to €815,087 per annum for this operation mode. Teleneurological assessment reduced overall costs by 11.7%.
Conclusion: This analysis provides a framework of determinants and considerations to address during the design process of a novel MSU program to balance stroke care improvements with the sustainable use of scarce resources.
Limitations: The study is limited by using a model-based economic evaluation of MSU program costs and stroke case estimates.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: There was no ethical approval necessary as no human data was analysed.
7 min
Clinical scores and imaging-based thrombus biomarkers for predicting recanalisation after stent-retriever mechanical thrombectomy
Karina Janeth Gordillo Zabaleta, Barcelona / Spain
Author Block: K. J. Gordillo Zabaleta1, V. Cuba1, O. Chirife1, E. Ripoll1, S. Aixut1, L. Aja1, A. Nuñez1, M. Comas2, J. Puig2; 1Barcelona/ES, 2Girona/ES
Purpose: Stent-retrievers (SR) are safe and effective devices for acute ischaemic stroke due to large vessel occlusion (LVO). However, the efficacy of this technique in treating certain patients remains dubious. No imaging biomarkers are available to predict the efficacy of these devices. The prediction of a fast and complete recanalisation after a single device pass (first-pass effect, FPE) could improve and optimise decision-making in treating acute stroke. The objective of this study was to identify predictors of recanalisation after SR mechanical thrombectomy.
Methods or Background: We performed a retrospective observational study with prospective inclusion to assess the efficacy and safety of the Catchview Maxi stent-retriever device (BALT, Montmorency, France). We included 94 stroke patients with LVO. Location, length, visual density, attenuation Hounsfield Unit (HU) coefficient, and permeability were the thrombus-related parameters analysed on non-contrast CT and CT angiography. Collaterals and intracranial vascular calcification were also evaluated. FPE was defined as the achievement of mTICI2c-3.
Results or Findings: FPE (26 patients, 28.3%) was associated with smoking (p=0.030), greater rates of baseline mRS 0-2 (p=0.008), lower NIHSS score at baseline (p=0.040), 24-NIHSS score (p<0.001), greater rates of 90-day mRS 0-2 (p=0.003), shorter thrombus length (p=0.05), and good collaterals (p=0.070). Patients with final mTICI 2c/3 (63 patients, 66%) were younger (median age, 74 vs 80 years; p<0.001), had lower 24-NIHSS score (16 vs 19; p=0.010), higher greater rates of good functional outcome at 90 days (mRS 0-2, 40.7% vs 7.1%; p=0.003), lower 24h-infarct volume (23.9 vs 98 mL; p=0.057), higher thrombus HU ratio (1.3 vs 1.2; p=0.034), and higher thrombus permeability (enhancement percentage difference, 38.7 vs 21.9; p=0.016).
Conclusion: Combining clinical scores and imaging-based thrombus biomarkers is useful for predicting recanalisation after SR mechanical thrombectomy.
Limitations: This was a monocentric retrospective study design.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: This study was approved by BITE-OUT (reference number of approval: PR237/23).
7 min
Haemodynamic consequences in endovascular treatment of symptomatic carotid stenosis: a comprehensive analysis
José Rodríguez Castro, Oviedo / Spain
Author Block: J. Rodríguez Castro1, E. Murias Quintana1, S. Budiño Torres1, J. M. Jiménez Pérez1, M. García Ramos1, E. Uceda Andrés1, P. García Martínez2, P. Vega Valdés1; 1Oviedo/ES, 2Salamanca/ES
Purpose: The purpose of this study was to assess the prevalence of bradycardia and hypotension during and immediately post-endovascular intervention in patients with symptomatic carotid stenosis. Additionally, the research explores personal variables, radiological stenosis characteristics, procedural techniques, and associated medical complications contributing to these symptoms.
Methods or Background: We conducted a retrospective observational cohort study, analysing a registry of 54 patients who underwent angioplasty and stent placement for symptomatic carotid stenosis at our centre. A thorough collection of clinical and analytical variables was performed for subsequent statistical analysis.
Results or Findings: Of the sampled patients, 34% (17) experienced haemodynamic depression post-procedure, with only four presenting symptoms. Notably, three symptomatic patients were smokers, and two consumed over 40 standard drink units (SDUs) of alcohol daily. The four patients with hypotension had significant contralateral internal carotid artery (ICA) stenosis. Among those with bradycardia, 10 of 16 had stenosis near the carotid bifurcation. Interestingly, patients developing complications had shorter hospitalisation times compared to those without.
Conclusion: The incidence of haemodynamic depression in patients with symptomatic carotid stenosis undergoing angioplasty and stent placement is 34%. Elevated alcohol consumption (>40 SDUs/day) and significant contralateral ICA stenosis increase the risk of post-treatment hypotension in our series. Characteristics of the stent, angioplasty balloon, use of corticosteroids, and procedural duration showed no correlation with haemodynamic depression. Development of haemodynamic depression post-angioplasty does not necessitate prolonged hospitalisation or increase in serious complications.
Limitations: While our study sheds light on significant associations, the retrospective nature and limited sample size may warrant further investigation for a more comprehensive understanding.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: Written consent has been obtained from all patients to receive the described treatment. Patient data has been anonymised. Due to the nature of this study involving a routine interventional procedure, specific consent from the Hospital Ethics Committee was not required.
7 min
Post-stroke cerebral blood flow derived from arterial spin labelling as a biomarker of clinical outcome following endovascular therapy
Nico Sollmann, Ulm / Germany
Author Block: M. R. Hernandez Petzsche1, G. Hoffmann1, C. Zimmer1, C. Maegerlein1, T. Boeckh-Behrens1, S. Wunderlich1, S. Kaczmarz1, M. T. Berndt1, N. Sollmann2; 1Munich/DE, 2Ulm/DE
Purpose: Arterial spin labelling (ASL) enables measuring cerebral blood flow (CBF), and it has been proposed to be sensitive to detect perfusion changes following ischaemic stroke. Post-stroke infarct perfusion has been associated with higher risk of haemorrhagic transformation (HT) and better clinical outcome. This study aimed to evaluate ASL-based CBF in the infarct core as a prognostic biomarker for clinical outcome, and to investigate the relationship between CBF increase and HT risk.
Methods or Background: 111 patients (median age: 74 years, 50 men) underwent cerebral MRI (median 4 days after mechanical thrombectomy for ischaemic stroke due to large vessel occlusion of the anterior circulation) including pseudo-continuous ASL, diffusion-weighted imaging (DWI), and susceptibility-weighted imaging (SWI). %CBF increase was calculated within the segmented DWI-positive infarct territory (in relationship to the unaffected contralateral side). Functional independence was defined as a modified Rankin Scale (mRS) 0-2 at 90 days post-stroke. National Institutes of Health Stroke Scale (NIHSS) scores were determined at admission.
Results or Findings: In univariate analysis, age (odds ratio (OR)=0.97, p=0.03), pre-stroke mRS (OR=0.36, p<0.001), NIHSS at admission (OR=0.93, p=0.04), Alberta Stroke Program Early Computed Tomography Score (ASPECTS) at admission (OR=1.26, p=0.03), complete recanalisation (OR=2.95, p=0.03), DWI-positive infarct volume on post-treatment MRI (OR=0.994, p=0.002), and %CBF increase (OR=1.009, p=0.04) were associated with functional independence. In multivariate regression, %CBF increase (OR=1.01, p=0.02), pre-stroke mRS (OR=0.30, p<0.001), and infarct volume (OR=0.99, p=0.001) were significantly associated with functional independence. Post-stroke infarct %CBF increase was comparable between patients with and without HT (median %CBF increase 20.6 in patients without HT and 9.8 in patients with HT, p=0.45).
Conclusion: ASL-derived %CBF increase from DWI-positive infarct territories may independently predict functional independence. Yet, infarct %CBF increase was not significantly associated with increased risk of HT.
Limitations: No limitations were identified.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the Technical University of Munich Ethics Committee.
7 min
Automated MRI-based basal ganglia and thalamus assessment at the acute-subacute phase after middle cerebral cortical stroke can help predict the 3-month mRS shift
Salim Zenkhri, Lausanne / Switzerland
Author Block: S. Zenkhri, M. Bénédicte, R. Corredor-Jerez, D. Strambo, P. Michel, V. Dunet; Lausanne/CH
Purpose: The purpose of this study was to evaluate the prognostic value of individual volumetric and ADC variations of the basal ganglia (BG) and thalamus during the acute-subacute phases following a cortical middle cerebral artery (MCA) stroke to predict the modified Rankin scale (mRS) at 3 months.
Methods or Background: In this retrospective single-centre study, 153 patients (69.3±15.3 years, 85 males) admitted for MCA cortical stroke at the acute-subacute phase (<21 days) from January 2018 to October 2020 were included. MR performed on a 3T (MAGNETOM Vida, Siemens) with DWI and T1-MP-RAGE sequences were used for analysis. T1-MP-RAGE images were processed with the MorphoBox© research application to automatically segment BG and thalamus and compute Z-scores considering the confounding effects of age and sex. ADC values were extracted from the co-registration between ADC map and segmented T1-MP-RAGE. The differences between ipsilateral and contralateral values to stroke, and asymmetric index were computed. Stroke volume was manually segmented on DWI. Multivariate regression analysis was performed to search for predictors of 3-months mRS.
Results or Findings: The mean stroke volume was 8.3±20.5ml. The mean delay between stroke onset and MRI evaluation was 56.5±78.5 hours. The Z-score difference between thalami correlated with the core volume (β=0.29, p<0.001) and delay from stroke onset (β=0.18, p=0.038). The ADC mean value difference between thalami correlated with the delay from stroke onset (F=6.55, p=0.0003). Asymmetric Z-score putamen index (F=5.50, p=0.021) and ADC thalamus index (F=5.49, p=0.021) independently predicted mRS shift at 3 months.
Conclusion: At the acute-subacute phase of MCA cortical stroke, a reduced thalamic and BG volume and low ADC on the stroke side correlate with core volume and delay from onset. They could additionally help to predict mRS shift at 3 months.
Limitations: This is a retrospective monocentric analysis.
Funding for this study: The authors of this research declare no conflict of interest, and no funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/ or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. All collected data were anonymised to comply with national ethical guidelines and laws. Therefore, patients’ consent was waived.
7 min
Dual-energy computed tomography can detect subclinical abnormalities of high density in the gyrus in patients after neuro-endovascular treatment
Sangil Suh, Seoul / Korea, Republic of
Author Block: S. Suh, P. Byeongsu, J. H. Han; Seoul/KR
Purpose: Abnormal high density in the gyrus (AHDG) frequently appears in non-contrast brain CT scans post-neuro-endovascular procedures utilising iodinated contrast. The exact nature of AHDG remains elusive. This study employs Dual-Energy CT (DECT) to explore whether AHDG could represent a 'minor' subarachnoid haemorrhage, confirming that it is iodine, not blood. We aimed to elucidate the nature, incidence, and risk factors of AHDG observed in DECT scans post-embolisation of unruptured intracranial aneurysms.
Methods or Background: A retrospective review of clinical data from 230 patients who underwent endovascular embolisation for unruptured intracranial aneurysms at our hospital from October 2018 to March 2023 was conducted. Low- and high-energy images were analysed using a 3-material decomposition algorithm focused on brain parenchyma, haemorrhage, and iodine. The osmolality of the contrast agents used in the procedures was 290mOsm/kg, 515mOsm/kg, and 616mOsm/kg. Chi-squared tests and logistic regression analyses were utilised to identify risk factors associated with AHDG.
Results or Findings: DECT images of 230 patients were visually inspected, and three physicians independently analysed them, ensuring strong interobserver agreement. Consensus was reached through discussion in cases of discrepancy. Among the patients, 96 (41.7%) exhibited AHDG. Chi-squared tests revealed significant relationships between AHDG and variables like sex, aneurysm location, and usage of higher osmolarity contrast agents. Logistic regression analyses demonstrated significant correlations between AHDG and age (OR 1.03), procedure time (OR 1.02 per minute), aneurysm location (OR 10.15), and the usage of higher osmolarity contrast agents (OR 2.70).
Conclusion: DECT effectively detects AHDG in patients with unruptured intracranial aneurysms post-embolisation. The findings underscore the need for further research to unravel the complex relationships between the osmolarity of contrast agents and the incidence of AHDG.
Limitations: No limitations were identified.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Ethics committee approval is in progress.

This session will not be streamed, nor will it be available on-demand!