Machine learning predicts peak oxygen uptake and peak power output for customizing cardiopulmonary exercise testing using non-exercise features.

PURPOSE: Cardiopulmonary exercise testing (CPET) is considered the gold standard for assessing cardiorespiratory fitness. To ensure consistent performance of each test, it is necessary to adapt the power increase of the test protocol to the physical characteristics of each individual. This study aimed to use machine learning models to determine individualized ramp protocols based on non-exercise features. We hypothesized that machine learning models will predict peak oxygen uptake ( V ˙ O2peak) and peak power output (PPO) more accurately than conventional multiple linear regression (MLR). METHODS: The cross-sectional study was conducted with 274 (♀168, ♂106) participants who performed CPET on a cycle ergometer. Machine learning models and multiple linear regression were used to predict V ˙ O2peak and PPO using non-exercise features. The accuracy of the models was compared using criteria such as root mean square error (RMSE). Shapley additive explanation (SHAP) was applied to determine the feature importance. RESULTS: The most accurate machine learning model was the random forest (RMSE: 6.52 ml/kg/min [95% CI 5.21-8.17]) for V ˙ O2peak prediction and the gradient boosting regression (RMSE: 43watts [95% CI 35-52]) for PPO prediction. Compared to the MLR, the machine learning models reduced the RMSE by up to 28% and 22% for prediction of V ˙ O2peak and PPO, respectively. Furthermore, SHAP ranked body composition data such as skeletal muscle mass and extracellular water as the most impactful features. CONCLUSION: Machine learning models predict V ˙ O2peak and PPO more accurately than MLR and can be used to individualize CPET protocols. Features that provide information about the participant's body composition contribute most to the improvement of these predictions. TRIAL REGISTRATION NUMBER: DRKS00031401 (6 March 2023, retrospectively registered).

Improved rates of postoperative ischemia, completeness of aneurysm occlusion and neurological deficits in elective clipping of anterior circulation aneurysms over the past 20 years - association with technical improvements.

BACKGROUND/PURPOSE: Several periprocedural adjuncts for elective surgical aneurysm treatment have been introduced over the last 20 years to increase safety and efficacy. Besides the introduction of IONM in the late-1990s, ICG-videoangiography (ICG-VAG) since the mid-2000s and intraoperative CT-angiography/-perfusion (iCT-A/-P) since the mid-2010s are available. We aimed to clarify whether the introduction of ICG-VAG and iCT-A/-P resulted in our department in a stepwise improvement in the rate of radiologically detected postoperative ischemia, complete aneurysm occlusion and postoperative new deficits. METHODS: Patients undergoing microsurgical clip occlusion for unruptured anterior circulation aneurysms between 2000 and 2019 were included, with ICG-VAG since 2009 and iCT-A/-P (for selected cases) since 2016. Baseline characteristics and treatment-related morbidity/outcome focusing on differences between the three distinct cohorts (cohort-I: pre-ICG-VAG-era, cohort-II: ICG-VAG-era, cohort-III: ICG-VAG&iCT-A/-P-era) were analyzed. RESULTS: 1391 patients were enrolled (n = 74 were excluded), 779 patients were interventionally treated, 538 patients were surgically clipped by a specialized vascular team (cohort-I n = 167, cohort-II n = 284, cohort-III n = 87). Aneurysm size was larger in cohort-I (8.9 vs. 7.5/6.8 mm; p < 0.01) without differences concerning age (mean:55years), gender distribution (m: f = 1:2.6) and aneurysm location (MCA:61%, ICA:18%, ACA/AcomA:21%). There was a stepwise improvement in the rate of radiologically detected postoperative ischemia (16.2vs.12.0vs.8.0%; p = 0.161), complete aneurysm occlusion (68.3vs.83.6vs.91.0%; p < 0.01) and postoperative new deficits (10.8vs.7.7vs.5.7%; p = 0.335) from cohort-I to -III. After a mean follow-up of 12months, a median modified Rankin scale of 0 was achieved in all cohorts. DISCUSSION: Associated with periprocedural technical achievements, surgical outcome in elective anterior circulation aneurysm surgery has improved in our service during the past 20 years.

Circadian rhythm of ischaemic core progression in human stroke.

INTRODUCTION: Experimental stroke studies suggest an influence of the time of day of stroke onset on infarct progression. Whether this holds true after human stroke is unknown, but would have implications for the design of randomised controlled trials, especially those on neuroprotection. METHODS: We pooled data from 583 patients with anterior large-vessel occlusion stroke from three prospectively recruited cohorts. Ischaemic core and penumbra volumes were determined with CT perfusion using automated thresholds. Core growth was calculated as the ratio of core volume and onset-to-imaging time. To determine circadian rhythmicity, we applied multivariable linear and sinusoidal regression analysis adjusting for potential baseline confounders. RESULTS: Patients with symptom onset at night showed larger ischaemic core volumes on admission compared with patients with onset during the day (median, 40.2 mL vs 33.8 mL), also in adjusted analyses (p=0.008). Sinusoidal analysis indicated a peak of core volumes with onset at 11pm. Core growth was faster at night compared with day onset (adjusted p=0.01), especially for shorter onset-to-imaging times. In contrast, penumbra volumes did not change across the 24-hour cycle. DISCUSSION: These results suggest that human infarct progression varies across the 24-hour cycle with potential implications for the design and interpretation of neuroprotection trials.

Diagnostic value of water-fat-separated images and CT-like susceptibility-weighted images extracted from a single ultrashort echo time sequence for the evaluation of vertebral fractures and degenerative changes of the spine.

OBJECTIVES: To evaluate the performance of single-echo Dixon water-fat imaging and computed tomography (CT)-like imaging based on a single ultrashort echo time (sUTE) MR sequence for imaging of vertebral fractures as well as degenerative bone changes of the spine in comparison to conventional CT and MR sequences. METHODS: Thirty patients with suspected acute vertebral fractures were examined using a 3-T MRI, including an sUTE sequence as well as short-tau inversion recovery (STIR) and T1-weighted sequences. During postprocessing, water-fat separation was performed by solving the smoothness-constrained inverse water-fat problem based on a single-complex UTE image. By removing the unwanted low-frequency phase terms, additional MR-based susceptibility-weighted-like (SW-like) images with CT-like contrast were created. Two radiologists evaluated semi-quantitative and quantitative features of fractures and degenerative changes independently and separately on CT and MR images. RESULTS: In total, all 58 fractures were accurately detected of whom 24 were correctly classified as acute fractures with an edema detected on the water-fat-separated UTE images, using STIR and T1w sequences as standard of reference. For the morphological assessment of fractures and degenerative changes, the overall agreement between SW-like images and CT was substantial to excellent (e.g., Genant: κ 0.90 (95% confidence interval 0.54-1.00); AO/Magerl: κ 0.75 (95% confidence interval 0.43-1.00)). Overall inter-reader agreement for water-fat-separated UTE images and SW-like images was substantial to almost perfect. CONCLUSION: Detection and assessment of vertebral fractures and degenerative bone changes of the spine were feasible and accurate using water-fat-separated images as well as SW-like images, both derived from the same sUTE-Dixon sequence. KEY POINTS: • The detection of acute vertebral fractures was feasible using water-fat-separated images and CT-like images reconstructed from one sUTE sequence. • Assessment of the vertebral fractures using SW-like images with CT-like contrast was found to be comparable to conventional CT. • sUTE imaging of the spine can help reduce examination times and radiation exposure.

Endovascular thrombectomy for basilar artery occlusion stroke: Analysis of the German Stroke Registry-Endovascular Treatment.

BACKGROUND AND PURPOSE: Acute ischemic stroke due to basilar artery occlusion (BAO) causes the most severe strokes and has a poor prognosis. Data regarding efficacy of endovascular thrombectomy in BAO are sparse. Therefore, in this study, we performed an analysis of the therapy of patients with BAO in routine clinical practice. METHODS: Patients enrolled between June 2015 and December 2019 in the German Stroke Registry-Endovascular Treatment (GSR-ET) were analyzed. Primary outcomes were successful reperfusion (modified Thrombolysis in Cerebral Infarction [mTICI] score of 2b-3), substantial neurological improvement (≥8-point National Institute of Health Stroke Scale [NIHSS] score reduction from admission to discharge or NIHSS score at discharge ≤1), and good functional outcome at 3 months (modified Rankin Scale [mRS] score of 0-2). RESULTS: Out of 6635 GSR-ET patients, 640 (9.6%) patients (age 72.2 ± 13.3, 43.3% female) experienced BAO (median [interquartile range] NIHSS score 17 [8, 27]). Successful reperfusion was achieved in 88.4%. Substantial neurological improvement at discharge was reached by 45.5%. At 3-month follow-up, good clinical outcome was observed in 31.1% of patients and the mortality rate was 39.2%. Analysis of mTICI3 versus mTICI2b groups showed considerable better outcome in those with mTICI3 (38.9% vs. 24.4%; p = 0.005). The strongest predictors of good functional outcome were intravenous thrombolysis (IVT) treatment (odds ratio [OR] 3.04, 95% confidence interval [CI] 1.76-5.23) and successful reperfusion (OR 4.92, 95% CI 1.15-21.11), while the effect of time between symptom onset and reperfusion seemed to be small. CONCLUSIONS: Acute reperfusion strategies in BAO are common in daily practice and can achieve good rates of successful reperfusion, neurological improvement and good functional outcome. Our data suggest that, in addition to IVT treatment, successful and, in particular, complete reperfusion (mTICI3) strongly predicts good outcome, while time from symptom onset seemed to have a lower impact.

Comparative assessment of woven endobridge embolization and standard coil occlusion for the treatment of ruptured basilar tip aneurysms.

PURPOSE: Endovascular coil occlusion represents the standard treatment for basilar tip aneurysms. Recently, this role has been rivalled by intrasaccular flow disruptors across numerous centres. We retrospectively compared WEB embolization and coiling for the treatment of ruptured basilar tip aneurysms. METHODS: Patients treated with WEB or coiling at four neurovascular centres were reviewed. Procedure-related complications, clinical outcome, and angiographic results were retrospectively compared. RESULTS: The study included 23 patients treated with the WEB (aneurysm size: 6.6 ± 1.9 mm) and 56 by coiling (aneurysm size: 6.7 ± 2.5 mm). Stent-assistance was more often necessary with coiling than with WEB embolization (32% vs. 4%, p = 0.009). A modified Rankin scale score ≤ 2 at discharge had 21 (37.5%) patients in the coiling group and 12 (52.2%) in the WEB group (p = 0.235). Immediate complete and adequate occlusion rates were 52% for the WEB and 87% for coiling. At short-term follow-up, these rates were 87% for the WEB and 72% for coiling, respectively. There was no delayed aneurysm re-bleeding during follow-up. CONCLUSION: Both coiling and WEB seem to prevent rebleeding in ruptured BTA aneurysms. WEB embolization required less frequently stent-support than coiling, potentially advantageous for SAH patients to avoid anti-platelet therapy in the light of concomitant procedures like ventricular drainage.

Differentiation of benign and malignant vertebral fractures using a convolutional neural network to extract CT-based texture features.

PURPOSE: To assess the diagnostic performance of three-dimensional (3D) CT-based texture features (TFs) using a convolutional neural network (CNN)-based framework to differentiate benign (osteoporotic) and malignant vertebral fractures (VFs). METHODS: A total of 409 patients who underwent routine thoracolumbar spine CT at two institutions were included. VFs were categorized as benign or malignant using either biopsy or imaging follow-up of at least three months as standard of reference. Automated detection, labelling, and segmentation of the vertebrae were performed using a CNN-based framework ( https://anduin.bonescreen.de ). Eight TFs were extracted: Varianceglobal, Skewnessglobal, energy, entropy, short-run emphasis (SRE), long-run emphasis (LRE), run-length non-uniformity (RLN), and run percentage (RP). Multivariate regression models adjusted for age and sex were used to compare TFs between benign and malignant VFs. RESULTS: Skewnessglobal showed a significant difference between the two groups when analyzing fractured vertebrae from T1 to L6 (benign fracture group: 0.70 [0.64-0.76]; malignant fracture group: 0.59 [0.56-0.63]; and p = 0.017), suggesting a higher skewness in benign VFs compared to malignant VFs. CONCLUSION: Three-dimensional CT-based global TF skewness assessed using a CNN-based framework showed significant difference between benign and malignant thoracolumbar VFs and may therefore contribute to the clinical diagnostic work-up of patients with VFs.

Outcome of posterior decompression for spinal epidural lipomatosis.

BACKGROUND: In contrast to osteoligamentous lumbar stenosis (LSS), outcome of surgical treatment for spinal epidural lipomatosis (SEL) is still not well defined. We present risk factors for SEL and clinical long-term outcome data after surgical treatment for patients with pure SEL and a mixed-type pathology with combined SEL and LSS (SEL+LSS) compared to patients with pure LSS. METHODS: From our prospective institutional database, we identified all consecutive patients who were surgically treated for newly diagnosed SEL (n = 31) and SEL+LSS (n = 26) between 2018 and 2022. In addition, a matched control group of patients with pure LSS (n = 30) was compared. Microsurgical treatment aimed for posterior decompression of the spinal canal. Study endpoints were outcome data including clinical symptoms at presentation, MR-morphological analysis, evaluation of pain-free walking distance, pain perception by VAS-N/-R scales, and patient's satisfaction by determination of the Odom score. RESULTS: Patients with osteoligamentous SEL were significantly more likely to suffer from obesity (body mass index (BMI) of 30.2 ± 5.5 kg/m2, p = 0.03), lumbar pain (p = 0.006), and to have received long-term steroid therapy (p = 0.01) compared to patients with SEL+LSS and LSS. In all three groups, posterior decompression of the spinal canal resulted in significant improvement of these symptoms. Patients with SEL had a significant increase in pain-free walking distance during the postoperative course, at discharge, and last follow-up (FU) (p < 0.0001), similar to patients with SEL+LSS and pure LSS. In addition, patients with pure SEL and SEL+LSS had a significant reduction in pain perception, represented by smaller values of VAS-N and -R postoperatively and at FU, similar to patients with pure LSS. In uni- and multivariate analysis, domination of lumbar pain and steroid long-term therapy were significant characteristic risk factors for SEL. CONCLUSIONS: Surgical treatment of pure SEL and SEL+LSS allows significant improvement in pain-free walking distance and pain perception immediately postoperatively and in long-term FU, similar to patients with pure LSS.

Minor stroke in large vessel occlusion: A matched analysis of patients from the German Stroke Registry-Endovascular Treatment (GSR-ET) and patients from the Safe Implementation of Treatments in Stroke-International Stroke Thrombolysis Register (SITS-ISTR).

BACKGROUND AND PURPOSE: Reperfusion treatment in patients presenting with large vessel occlusion (LVO) and minor neurological deficits is still a matter of debate. We aimed to compare minor stroke patients treated with endovascular thrombectomy (EVT) and intravenous thrombolysis (IVT) or IVT alone. METHODS: Patients enrolled in the German Stroke Registry-Endovascular Treatment (GSR-ET) and the Safe Implementation of Treatments in Stroke-International Stroke Thrombolysis Registry (SITS-ISTR) between June 2015 and December 2019 were analyzed. Minor stroke was defined as National Institutes of Health Stroke Scale (NIHSS) score ≤5, and LVO as occlusion of the internal carotid, carotid-T, middle cerebral, basilar, vertebral or posterior cerebral arteries. GSR-ET and SITS-ISTR IVT-treated patients were matched in a 1:1 ratio using propensity-score (PS) matching. The primary outcome was good functional outcome at 3 months (modified Rankin Scale score 0-2). RESULTS: A total of 272 GSR-ET patients treated with EVT and IVT (age 68.6 ± 14.0 years, 43.4% female, NIHSS score 4 [interquartile range 2-5]) were compared to 272 IVT-treated SITS-ISTR patients (age 69.4 ± 13.7, 43.4% female, NIHSS score 4 [2-5]). Good functional outcome was seen in 77.0% versus 82.9% (p = 0.119), mortality in 5.9% versus 7.9% (p = 0.413), and intracranial hemorrhage in 8.8% versus 12.5% (p = 0.308) of patients in the GSR-ET versus the SITS-ISTR IVT group, respectively. In a second PS-matched analysis, 624 GSR-ET patients (IVT rate 56.7%) and 624 SITS-ISTR patients (IVT rate 100%), good outcome was more often observed in the SITS-ISTR patients (68.2% vs. 80.9%; p < 0.001), and IVT independently predicted good outcome (odds ratio 2.16, 95% confidence interval 1.43-3.28). CONCLUSIONS: Our study suggests similar effectiveness of IVT alone compared to EVT with or without IVT in minor stroke patients. There is an urgent need for randomized controlled trials on this topic.

Stent-assisted WEB embolization: aneurysm characteristics, outcome and case report of a WEB delivered through a stent.

PURPOSE: Woven Endobridge (WEB) embolization has become a well-established endovascular treatment option for wide-necked bifurcation aneurysms. The objective was to analyse cases that required additional stent-implantation. METHODS: Images of 178 aneurysms ≤ 11 mm treated by WEB only or by WEB plus stent were retrospectively reviewed, evaluating aneurysm characteristics, procedural specifics, adverse events and angiographic results. Moreover, we report a case of a WEB delivered through a previously implanted stent. RESULTS: Additional stent implantation was performed in 15 patients (8.4%). Baseline patient and aneurysm characteristics were comparable between both groups. A single stent was used in 12 cases and 2 stents in Y-configuration in 3. Thromboembolic complications occurred more often with stent assistance (33.3% vs. 8.0%, p = 0.002), while ischemic stroke rates were comparable between both groups (0% vs. 1.8%, p = 1.0). Six-month angiographic follow-up showed complete occlusion, neck remnants and aneurysm remnants in 73.4%, 19.4% and 7.3% after WEB only, respectively, and in 66.7%, 20.0% and 16.7% after WEB plus stent, respectively (p = 0.538). A case report shows that WEB deployment through the struts of a previously implanted standard microstent is feasible, even if a VIA 33 microcatheter is needed. CONCLUSION: In the present study, stent-assisted WEB embolization had a comparable safety and efficacy profile compared to treatment by WEB only. However, stent-assisted WEB embolization requires long-term anti-platelet medication, which annihilates the advantages of the WEB as a purely intrasaccular device. CLINICAL TRIAL REGISTRATION NUMBER: N/A.

Computed Tomography Perfusion Deficit Volumes Predict Functional Outcome in Patients With Basilar Artery Occlusion.

Background and Purpose: Basilar artery occlusion is associated with high morbidity and mortality. Optimal imaging and treatment strategy are still controversial and prognosis estimation challenging. We, therefore, aimed to determine the predictive value of computed tomography perfusion (CTP) parameters for functional outcome in patients with basilar artery occlusion in the context of endovascular treatment. Methods: Patients with basilar artery occlusion who underwent endovascular treatment were selected from a prospectively acquired cohort. Ischemic changes were assessed with the posterior-circulation Acute Stroke Prognosis Early Computed Tomography Score on noncontrast computed tomography, computed tomography angiography (CTA) source images, and CTP maps. Basilar artery on CTA score, posterior-circulation CTA score, and posterior-circulation collateral score were evaluated on CTA. Perfusion deficit volumes were quantified on CTP maps. Good functional outcome was defined as modified Rankin Scale score ≤3 at 90 days. Statistical analysis included binary logistic regressions and receiver operating characteristics analyses. Results: Among 49 patients who matched the inclusion criteria, 24 (49.0%) achieved a good outcome. In univariate analysis, age, National Institutes of Health Stroke Scale score on admission, posterior cerebral artery involvement, absence of or hypoplastic posterior communicating arteries, basilar artery on CTA score, posterior-circulation Acute Stroke Prognosis Early Computed Tomography Score, and perfusion deficit volumes on all CTP parameter maps presented significant association with functional outcome (P<0.05). In multivariate analyses, Basilar artery on CTA score, posterior-circulation Acute Stroke Prognosis Early Computed Tomography Score (odds ratio range, 1.31­2.10 [95% CI, 1.00­7.24]), and perfusion deficit volumes on all CTP maps (odds ratio range, 0.77­0.98 [95% CI, 0.63­1.00]) remained as independent outcome predictors. Cerebral blood flow deficit volume yielded the best performance for the classification of good clinical outcome with an area under the curve of 0.92 (95% CI, 0.84­0.99). Age and admission National Institutes of Health Stroke Scale had lower discriminatory power (area under the curve, <0.7). Conclusions: CTP imaging parameters contain prognostic information for functional outcome in patients with stroke due to basilar artery occlusion and may identify patients with higher risk of disability at an early stage of hospitalization.

Tandem Lesions in Anterior Circulation Stroke: Analysis of the German Stroke Registry-Endovascular Treatment.

[Figure: see text].

Circulating Metabolites Differentiate Acute Ischemic Stroke from Stroke Mimics.

OBJECTIVE: Early discrimination of patients with ischemic stroke (IS) from stroke mimics (SMs) poses a diagnostic challenge. The circulating metabolome might reflect pathophysiological events related to acute IS. Here, we investigated the utility of early metabolic changes for differentiating IS from SM. METHODS: We performed untargeted metabolomics on serum samples obtained from patients with IS (N = 508) and SM (N = 349; defined by absence of a diffusion weighted imaging [DWI] positive lesion on magnetic resonance imaging [MRI]) who presented to the hospital within 24 hours after symptom onset (median time from symptom onset to blood sampling = 3.3 hours; interquartile range [IQR] = 1.6-6.7 hours) and from neurologically normal controls (NCs; N = 112). We compared diagnostic groups in a discovery-validation approach by applying multivariable linear regression models, machine learning techniques, and propensity score matching. We further performed a targeted look-up of published metabolite sets. RESULTS: Levels of 41 metabolites were significantly associated with IS compared to NCs. The top metabolites showing the highest value in separating IS from SMs were asymmetrical and symmetrical dimethylarginine, pregnenolone sulfate, and adenosine. Together, these 4 metabolites differentiated patients with IS from SMs with an area under the curve (AUC) of 0.90 in the replication sample, which was superior to multimodal cranial computed tomography (CT; AUC = 0.80) obtained for routine diagnostics. They were further superior to previously published metabolite sets detected in our samples. All 4 metabolites returned to control levels by day 90. INTERPRETATION: A set of 4 metabolites with known biological effects relevant to stroke pathophysiology shows unprecedented utility to identify patients with IS upon hospital arrival, thus encouraging further investigation, including multicenter studies. ANN NEUROL 2020;88:736-746.

The clinical value of ceMRA versus DSA for follow-up of intracranial aneurysms treated by coil embolization: an assessment of occlusion classifications and impact on treatment decisions.

OBJECTIVE: The aim of this study was a detailed analysis of the value of contrast-enhanced magnetic resonance angiography (ceMRA) compared to digital subtraction angiography (DSA) for follow-up imaging of intracranial aneurysms treated by coil embolization. METHODS: Patients with coiled aneurysms and follow-up exams including both DSA and 3 T ceMRA were retrospectively identified. In blinded readings, both modalities were graded according to the modified Raymond-Roy classification (MRRC) and the Meyers scale. Additionally, readers were asked to make a decision regarding retreatment/follow-up based on the respective imaging findings. RESULTS: The study comprised 92 patients harboring 102 coiled aneurysms. There was good intermethod agreement of DSA and ceMRA concerning both the MRRC (κ = 0.64) and the Meyers scale (κ = 0.74). Agreement regarding occlusion of < 90% of the aneurysm (Meyers grade ≥ 2) was very good (κ = 0.87). Regarding the detection of a remnant with contrast between the coil mass and the aneurysm wall (MRRC IIIb), there were 12 discrepant findings and agreement was good (κ = 0.70). Comparing treatment/follow-up decisions, the two methods agreed very well (κ = 0.92). In seven patients with discrepant treatment decisions, the authors concurred with DSA in four cases and with ceMRA in three cases when evaluating both modalities together. Interval aneurysm growth was found in more cases with ceMRA (n = 19) than with DSA (n = 16). CONCLUSIONS: CeMRA is very unlikely to miss a relevant aneurysm remnant and thus could be suitable as the primary follow-up method. In case of remnant growth or recurrence, however, additional DSA might be required to guide treatment decisions. KEY POINTS: • There is high accordance between ceMRA and DSA regarding the evaluation of intracranial aneurysms treated by endovascular coil embolization, but closer analysis also revealed relevant differences. • CeMRA could be suitable as the primary follow-up imaging modality, potentially eliminating the need for routine DSA. • DSA will still be required in case of aneurysm remnant growth or recurrence as detected by ceMRA.

Safety and efficacy of mechanical thrombectomy in infective endocarditis: A matched case-control analysis from the German Stroke Registry-Endovascular Treatment.

BACKGROUND AND PURPOSE: Up to 30% of infective endocarditis (IE) patients have ischemic stroke as a complication. Standard treatment with mechanical thrombectomy (MT) with or without intravenous thrombolysis for large vessel occlusion (LVO) has not been evaluated formally in these patients. METHODS: Patients enrolled in the German Stroke Registry-Endovascular Treatment (GSR-ET) between June 2015 and December 2019 were analyzed. Patients with stroke due to IE and patients with cardioembolic stroke and atrial fibrillation (AF) were compared using propensity score matching. Successful reperfusion was defined as modified Thrombolysis in Cerebral Infarction score = 2b-3. Modified Rankin Scale (mRS) = 0-2 at 3 months indicated good outcome. RESULTS: Of 6635 patients, 55 patients (age = 69.0 ± 13.3 years, 43.6% female, median premorbid mRS (pmRS) = 1, interquartile range [IQR] = 0-1, National Institutes of Health Stroke Scale [NIHSS] = 15, IQR = 10-21) presented with septic embolic stroke due to IE and were compared to 104 patients (age = 66.5 ± 13.4 years, 39.4% female, pmRS = 0, IQR = 0-2, NIHSS = 16, IQR = 10-20) with cardioembolic stroke due to AF. Successful recanalization was achieved in 74.5% of endocarditis patients compared to 87.5% of controls (p = 0.039). Intracranial hemorrhage rates were comparable (30.9% vs. 21.6%, p = 0.175). Good functional outcome was 20.0% in patients with IE compared to 43.3% in matched patients (p = 0.006), with a significantly higher mortality (60.0% vs. 28.8%, p < 0.001). IE was strongly associated with poor outcome (odds ratio [OR] = 0.32, 95% confidence interval [CI] = 0.11-0.87, p = 0.03 for good outcome) and mortality (OR = 4.49, 95% CI = 1.80-10.68, p = 0.001). CONCLUSIONS: Although MT results in high successful recanalization rates with acceptable safety profile, patients with LVO stroke due to IE have poor outcome.

Endovascular treatment of basilar tip aneurysms in the era of endosaccular flow disruption: a comparative study.

PURPOSE: This study aims to compare endosaccular flow disruptor (EFD) for treatment of basilar tip aneurysm (BTA) with coiling in terms of safety and efficacy. METHODS: We retrospectively reviewed patients treated with an EFD for BTAs at our institution between 2013 and 2019 to standard coiling from the same period (control group). Patient demographics, aneurysm characteristics, procedural data, complications and clinical and angiographic outcome were compared between groups. RESULTS: Twenty-three (56%) patients were treated with an EFD and eighteen (44%) patients were treated with coiling. Average aneurysm size was 8 mm in the EFD group and 6.9 mm in the coiling group, respectively (P = 0.2). Average fluoroscopy time, treatment DAP and air kerma were 33 min, 76 Gycm2 and 1.7 Gy in the EFD group and 81 min, 152 Gycm2 and 3.8 Gy in the coiling group, respectively (P < 0.001). In the EFD group, clinically relevant thromboembolic complications occurred in one patient (4%) vs. in 5 patients (28%) in the coiling group (P = 0.07). In each group, 4 patients had an unfavourable outcome at discharge (P = 0.7). Adequate occlusion rates were 96% in the EFD group and 100% and coiling group. Six (26%) patients were prescribed long-term antiplatelet therapy in the EFD group vs. eleven (61%) patients in the coiling group (P = 0.02). CONCLUSION: Both treatment concepts provided similar technical success and safety. However, procedure time, radiation exposure and a need for long-term antiaggregation were lower with EFD.

Direct puncture of the carotid artery as a bailout vascular access technique for mechanical thrombectomy in acute ischemic stroke-the revival of an old technique in a modern setting.

PURPOSE: To describe our single-center experience of mechanical thrombectomy (MTE) via a direct carotid puncture (DCP) with regard to indication, time metrics, procedural details, as well as safety and efficacy aspects. METHODS: DCP thrombectomy cases performed at our center were retrospectively identified from a prospectively maintained institutional MTE database. Various patient (age, sex, stroke cause, comorbidities), clinical (NIHSS, mRS), imaging (occlusion site, ASPECT score), procedural (indication for DCP, time from DCP to reperfusion, materials used, technical nuances), and outcome data (NIHSS, mRS) were tabulated. RESULTS: Among 715 anterior circulation MTEs, 12 DCP-MTEs were identified and analyzed. Nine were left-sided M1 occlusions, one right-sided M1 occlusion, and two right-sided M2 occlusions. DCP was successfully carried out in 91.7%; TICI 2b/3-recanalization was achieved in 83.3% via direct lesional aspiration and/or stent-retrieval techniques. Median time from DCP to reperfusion was 23 min. Indications included futile transfemoral catheterization attempts of the cervical target vessels as well as iliac occlusive disease. Neck hematoma occurred in 2 patients, none of which required further therapy. CONCLUSION: MTE via DCP in these highly selected patients was reasonably safe, fast, and efficient. It thus represents a valuable technical extension of MTE, especially in patients with difficult access.

Detection of impending perfusion deficits by intraoperative computed tomography (iCT) in aneurysm surgery of the anterior circulation.

BACKGROUND: The aim of our study was to evaluate the additional benefit of intraoperative computed tomography (iCT), intraoperative computed tomography angiography (iCTA), and intraoperative computed tomography perfusion (iCTP) in the intraoperative detection of impending ischemia to established methods (indocyanine green videoangiography (ICGVA), microDoppler, intraoperative neuromonitoring (IONM)) for initiating timely therapeutic measures. METHODS: Patients with primary aneurysms of the anterior circulation between October 2016 and December 2019 were included. Data of iCT modalities compared to other techniques (ICGVA, microDoppler, IONM) was recorded with emphasis on resulting operative conclusions leading to inspection of clip position, repositioning, or immediate initiation of conservative treatment strategies. Additional variables analyzed included patient demographics, aneurysm-specific characteristics, and clinical outcome. RESULTS: Of 194 consecutive patients, 93 patients with 100 aneurysms received iCT imaging. While IONM and ICGVA were normal, an altered vessel patency in iCTA was detected in 5 (5.4%) and a mismatch in iCTP in 7 patients (7.5%). Repositioning was considered appropriate in 2 patients (2.2%), where immediate improvement in iCTP could be documented. In a further 5 cases (5.4%), intensified conservative therapy was immediately initiated treating the reduced CBP as clip repositioning was not considered causal. In terms of clinical outcome at last FU, mRS0 was achieved in 85 (91.4%) and mRS1-2 in 7 (7.5%) and remained mRS4 in one patient with SAH (1.1%). CONCLUSIONS: Especially iCTP can reveal signs of impending ischemia in selected cases and enable the surgeon to promptly initiate therapeutic measures such as clip repositioning or intraoperative onset of maximum conservative treatment, while established tools might fail to detect those intraoperative pathologic changes.

Stroke Etiology Modifies the Effect of Endovascular Treatment in Acute Stroke.

Background and Purpose- Stroke etiology drives thrombus composition. We thus hypothesized that endovascular treatment shows different efficacy in cardioembolic versus noncardioembolic large-vessel occlusions (LVOs). Methods- Procedural characteristics, grade of reperfusion, and functional outcome at discharge and 90 days were compared between patients with cardioembolic versus noncardioembolic LVO from the GSR-ET (German Stroke Registry-Endovascular Treatment; n=2589). To determine associations with functional outcome, adjusted odds ratios and 95% CIs were calculated using ordinal multivariable logistic regression models adjusting for potential baseline confounder variables. Results- Endovascular treatment of cardioembolic LVO had a higher rate of successful reperfusion (85.6% versus 81.0%; P=0.002) and a higher rate of complete reperfusion after a single thrombectomy pass (45.7% versus 38.1%; P<0.001) compared with noncardioembolic LVO. Cardioembolic LVO was associated with better functional outcome at discharge (adjusted odds ratio, 1.61 [95% CI, 1.37-1.88]) and 90 days (adjusted odds ratio, 1.29 [95% CI, 1.09-1.53]). In mediation analysis, reperfusion explained 47% of the effect of etiology on functional outcome at discharge. Conclusions- These results provide evidence for higher efficacy of endovascular treatment in cardioembolic LVO compared with noncardioembolic LVO.

Radiation dose and fluoroscopy time of modern endovascular treatment techniques in patients with saccular unruptured intracranial aneurysms.

OBJECTIVES: Modern endovascular treatment of unruptured intracranial aneurysms (UIAs) demands for observance of diagnostic reference levels (DRLs). The national DRL (250 Gy cm2) is only defined for coiling. We provide dosimetric data for the following procedures: coiling, flow diverter (FD), Woven EndoBridge (WEB), combined techniques. METHODS: A retrospective single-centre study of saccular UIAs treated between 2015 and 2019. Regarding dosimetric analysis, the parameters dose area product (DAP) and fluoroscopy time were investigated for the following variables: endovascular technique, aneurysm location, DSA protocol, aneurysm size, and patient age. RESULTS: Eighty-seven patients (59 females, mean age 54 years) were included. Total mean and median DAP (Gy cm2) were 119 ± 73 (89-149) and 94 (73; 130) for coiling, 128 ± 53 (106-151) and 134 (80; 176) for FD, 128 ± 56 (102-153) and 118 (90; 176) for WEB, and 165 ± 102 (110-219) and 131 (98; 209) for combined techniques (p > .05). Regarding the aneurysm location, neither DAP nor fluoroscopy time was significantly different (p > .05). The lowest and highest fluoroscopy times were recorded for WEB and combined techniques, respectively (median 26 and 94 min; p < .001). A low-dose protocol yielded a 43% reduction of DAP (p < .001). Significantly positive correlations were found between DAP and both aneurysm size (r = .320, p = .003) and patient age (r = .214, p = .046). CONCLUSIONS: This UIA study establishes novel local DRLs for modern endovascular techniques such as FD and WEB. A low-dose protocol yielded a significant reduction of radiation dose. KEY POINTS: • This paper establishes local diagnostic reference levels for modern endovascular treatment techniques of unruptured intracranial aneurysms, including flow diverter stenting and Woven EndoBridge device. • Dose area product was not significantly different between endovascular techniques and aneurysm locations, but associated with aneurysm size and patient age. • A low-dose protocol yielded a significant reduction of dose area product and is particularly useful when applying materials with a high radiopacity (e.g. platinum coils).