Stephan Meckel

Background: Tentorial dural arteriovenous fistulas (TDAVFs) are rare but high risk vascular lesions. Although endovascular embolization is often the preferred treatment, large scale data on efficacy and safety are limited. Objective: To investigate the efficacy and safety of endovascular treatment for TDAVFs in a large, retrospective, multicenter cohort, and to analyze lesion characteristics and outcomes according to TDAVF location. Methods: Clinical, radiological, and interventional data from 585 patients treated in 32 international centers in 758 endovascular treatment sessions between 2012 and 2022 were analyzed. Patient demographics, fistula characteristics, endovascular treatment techniques, complications, and outcomes were assessed. Efficacy was measured by occlusion rates, safety by symptomatic complications, and modified Rankin Scale (mRS) scores. Results: In 31.3% of cases TDAVFs initially presented with hemorrhage, including 12.8% in low grade TDAVFs (absence of cortical venous reflux). Transarterial embolization was the primary approach in 84.7% of sessions. Complete occlusion was achieved in 74.2% of cases after the last treatment and 85.7% at the last imaging follow-up (mean 20.9 months). Symptomatic complications occurred in 9.4% of patients, with 2.6% permanent deficits and 1.0% mortality. At the last clinical follow-up (mean 30.6 months), 89.2% of patients had good functional outcome (mRS score 0–2). Location was significantly associated with fistula grade (eg, galenic and tentorial sinus TDAVFs being more often high grade, and torcular TDAVFs being more often low-grade). Conclusions: This large multicenter series demonstrated high occlusion rates, favorable functional outcomes, and acceptable complication rates, supporting endovascular therapy as a treatment of choice for TDAVFs. Considerable hemorrhage rates in low grade TDAVFs support the treatment even in the absence of cortical venous reflux.

BACKGROUND: Clinical scores indicating large vessel occlusion (LVO) in acute stroke patients could streamline triage of patients with suspected LVO to endovascular centers. GFAP (glial fibrillary acidic protein) is a promising blood biomarker for indicating intracerebral hemorrhage in acute stroke. This study evaluates whether positive LVO score results combined with a prehospital negative GFAP test (thereby excluding intracerebral hemorrhage) could improve the accuracy of LVO detection. METHODS: This retrospective diagnostic accuracy study (DETECT LVO) is based on the prospective DETECT study (2022–2024, tertiary care hospital RKH Klinikum Ludwigsburg, Germany), which evaluated the rapid intracerebral hemorrhage detection in acute stroke by measuring prehospital plasma GFAP levels on a point-of-care platform (i-STAT Alinity Abbott). For DETECT LVO, 5 established LVO scores (Rapid Arterial Occlusion Evaluation, Field Assessment Stroke Triage for Emergency Destination, 3-Item Stroke Scale, Emergency Medical Stroke Assessment, Cincinnati Prehospital Stroke Scale) were retrospectively calculated from paramedic protocols. LVOs were diagnosed with CT angiography as follows: occlusion of the internal carotid artery, middle cerebral artery, and basilar artery. Diagnostic accuracy for LVO detection was determined using the area under the curve, sensitivity, specificity, positive predictive values, and negative predictive values. RESULTS: Three hundred fifty-three patients suspected of acute stroke (ischemic stroke, n=258; intracerebral hemorrhage, n=76; stroke mimics, n=19) with a mean age of 74.6 years were included. One hundred one patients with ischemic stroke suffered from LVO (internal carotid artery=23.8%; middle cerebral artery=64.4%; and basilar artery=11.9%). Integrating GFAP to LVO scores significantly increased area under the curve (95% CI) for LVO detection (Field Assessment Stroke Triage for Emergency Destination, 0.859 [0.818–0.893] to 0.899 [0.862–0.928]; Rapid Arterial Occlusion Evaluation, 0.845 [0.802–0.880] to 0.892 [0.855–0.923]; 3-Item Stroke Scale, 0.788 [0.741–0.829] to 0.865 [0.824–0.898]; Emergency Medical Stroke Assessment, 0.840 [0.796–0.875] to 0.870 [0.830–0.910]; Cincinnati Prehospital Stroke Scale, 0.827 [0.784–0.865] to 0.862 [0.821–0.896]; P <0.001). CONCLUSIONS: Integrating LVO scores combined with GFAP measurements into the prehospital work-up of patients with acute stroke improves diagnostic accuracy for LVO prediction. In the future, this could enable direct transfers of patients with suspected LVO to endovascular centers with reduced misdiagnosis rates. Independent replication in diverse prehospital cohorts is warranted to confirm these findings.

Mechanical thrombectomy is the standard of care for acute ischemic stroke due to large vessel occlusion, but the optimal combination of devices remains under investigation. The SEMTiC-01 trial evaluates the safety and efficacy of a novel, fully integrated neurothrombectomy system composed of the iNedit balloon distal access catheter, the iNdeep microcatheter, and the iNtercept stent retriever. SEMTiC-01 is a prospective, multicenter, single-arm, open-label trial conducted across 18 centers in Spain, Germany, and Belgium. A total of 175 patients with LVO stroke were enrolled and treated within 24h of symptom onset. The primary efficacy endpoint was the rate of successful reperfusion (eTICI ≥2b) in ≤3 passes. The primary safety endpoints included serious adverse events within 24h and 90-day mortality. Secondary endpoints included good functional outcome (mRS 0-2 at 90 days), early neurological improvement, and device navigability. Successful reperfusion was achieved in 75.4% of the intention-to-treat (ITT) and 83.6% of the per-protocol (PP) population. Good functional outcomes were observed in 55.8% (ITT) and 56.9% (PP), and rapid neurological improvement in 64.6% of patients. First-pass reperfusion (eTICI ≥2b) was obtained in 46.9% (ITT) and 51.4% (PP). Symptomatic intracranial hemorrhage occurred in 1.7% (ITT), and mortality at 90 days was 13.7%. Device navigability was rated "Good" in over 75% of cases for both iNedit, iNtercept and iNdeep. Balloon inflation during thrombectomy improved outcomes in M1 occlusions. The triad system (iNedit, iNdeep and iNtercept) demonstrates non-inferiority compared published literature, with favorable safety and efficacy profiles. Its favourable navigability suggests it is a promising option for mechanical thrombectomy in acute ischemic stroke.

Purpose: Techniques for endovascular thrombectomy in acute ischemic stroke due to medium or distal vessel occlusions (MDVO) need to be improved, and first-line aspiration is emerging as a promising technique. The objective was to describe first-pass and final reperfusion rates with a triaxial direct aspiration first pass technique (ADAPT) and a novel, quadriaxial technique (QUATTRO-ADAPT) using RED43 Reperfusion Catheters to target MDVOs. Methods: This retrospective study collected data from 11 stroke centers in Europe and North America between 2023 and 2025. Patients with primary, isolated MDVOs who underwent thrombectomy using first-line aspiration with RED43 Reperfusion Catheters were included. Primary outcome was first-pass successful reperfusion rate (modified Treatment In Cerebral Infarction score ≥ 2b). Additionally, final reperfusion rates, complications and functional outcomes up to 90 days were evaluated. Results: We included 85 cases. Median age was 74 years (IQR 67–81) and median National Institutes of Health Stroke Scale score 9 (IQR 6–15). The majority (69.4%) had an occlusion of the co- or nondominant M2 segment of the middle cerebral artery. First-pass successful reperfusion was 63.5% overall, with 55.6% for the triaxial ADAPT and 69.4% for the quadriaxial QUATTRO-ADAPT. Final successful reperfusion was achieved in 96.5%. Complications included vessel perforations (2.4%), subarachnoid hemorrhage (3.5%), parenchymal hematoma type 2 (2.4%), and symptomatic intracerebral hemorrhage (1.2%). Functional independence (modified Rankin Scale 0–2) at 90 days was observed in 58.7%. Conclusion: This study shows that first-line aspiration, especially in a quadriaxial approach, can be effective and safe. These findings should be evaluated in prospective trials.

Background: Clinical and administrative studies suggest better functional outcomes after endovascular treatment (EVT) of intracranial aneurysms (IAs) compared to neurosurgical clipping (NSC). However, it remains unclear whether this applies to modern EVT techniques, such as balloon-assisted coiling (BAC), stent-assisted coiling (SAC), flow diversion (FD), or intrasaccular flow disruption (IFD). This study compares nationwide in-hospital outcomes of modern EVT methods and NSC with standard coiling (SC). Methods: Administrative data from all German hospitals (2013–2022) were analyzed using billing codes for SC, BAC, SAC, FD, IFD, and NSC in ruptured and unruptured IAs. Primary outcomes included functional independence (discharge type), poor outcomes (US Nationwide Inpatient Sample-Subarachnoid Hemorrhage Outcome Measure [NIS-SOM]), and in-hospital mortality. Propensity score weighting was used for comparisons. Results: A total of 77,684 procedures were analyzed (46.8% ruptured, 53.2% unruptured). In ruptured IAs, SAC, FD, and NSC were associated with lower functional independence (p=0.001, p=0.007, p<0.001) and higher mortality (p<0.001, p=0.001, p=0.032). Poor outcomes were more frequent after SAC (p=0.001) and NSC (p<0.001). In unruptured IAs, functional independence improved with BAC (p=0.036), SAC (p=0.045), and IFD (p<0.001), but decreased with NSC (p=0.017). Poor outcomes were less frequent with IFD (p<0.001), and mortality was lower with NSC (p=0.020) and IFD (p=0.003). Conclusions: Nationwide data from Germany reveal significant differences between EVT techniques and NSC for IA treatment. In ruptured IAs, SAC, FD, and NSC were associated with worse outcomes compared to SC. In unruptured IAs, BAC, SAC, and IFD improved functional outcomes, while NSC was linked to decreased functional outcomes. Notably, IFD consistently demonstrated superior functional outcomes despite limited utilization. Given the limitations of billing data, these findings suggest a potential shift favoring IFD as a safer treatment option in unruptured IAs.

Computational competitions are the standard for benchmarking medical image analysis algorithms, but they typically use small curated test datasets acquired at a few centers, leaving a gap to the reality of diverse multicentric patient data. To this end, the Federated Tumor Segmentation (FeTS) Challenge represents the paradigm for real-world algorithmic performance evaluation. The FeTS challenge is a competition to benchmark (i) federated learning aggregation algorithms and (ii) state-of-the-art segmentation algorithms, across multiple international sites. Weight aggregation and client selection techniques were compared using a multicentric brain tumor dataset in realistic federated learning simulations, yielding benefits for adaptive weight aggregation, and efficiency gains through client sampling. Quantitative performance evaluation of state-of-the-art segmentation algorithms on data distributed internationally across 32 institutions yielded good generalization on average, albeit the worst-case performance revealed data-specific modes of failure. Similar multi-site setups can help validate the real-world utility of healthcare AI algorithms in the future.

Background Subarachnoid hemorrhage (SAH) is a life-threatening condition with a high risk of disability requiring specialized care. This study investigated the relationship between hospital annual case volume and outcomes for patients undergoing clipping and endovascular treatment (EVT) of ruptured intracranial aneurysms (IAs) in Germany. Methods German Federal Statistical Office data (2013–2022) derived from all German hospitals were analyzed for ruptured IA cases treated with EVT or clipping. Primary outcomes were in-hospital mortality and poor neurological outcome according to the National Inpatient Sample-SAH Outcome Measure. Poisson regression was used to assess the annual case volume-outcome relationship. Results In 35 187 treatment cases for ruptured IA, a significant inverse relationship was found between annual case volume and both mortality and poor neurological outcomes for both treatment modalities. Each additional case performed annually decreased adverse outcome risk by 1%. EVT showed lower rates of poor neurological outcome (39.8% vs 49.8%, PConclusions This study is the first to quantify the volume-outcome relationship for treatment of ruptured IAs in Germany. Consistent results across treatment modalities suggest benefits of increased experience of neurovascular treatment centers. These findings enhance our understanding of factors influencing neurovascular care outcomes in Germany.

Purpose: Intracranial hypertension (IH) frequently complicates cerebral venous thrombosis (CVT). Distinct neuroimaging findings are associated with IH, yet their discriminative power, reversibility and factors favoring normalization in prospective CVT patients are unknown. We determined test performance measures of neuroimaging signs in acute CVT patients, their longitudinal change under anticoagulation, association with IH at baseline and with recanalization at follow-up. Methods: We included 26 consecutive acute CVT patients and 26 healthy controls. Patients were classified as having IH based on CSF pressure > 25 cmH₂O and/or papilledema on ophthalmological examination or ocular MRI. We assessed optic nerve sheath diameter (ONSD), optic nerve tortuousity, bulbar flattening, lateral and IV^th ventricle size, pituitary configuration at baseline and follow-up, and their association with IH and venous recanalization. Results: 46% of CVT patients had IH. ONSD enlargement > 5.8 mm, optic nerve tortuousity and pituitary grade ≥ III had highest sensitivity, ocular bulb flattening and pituitary grade ≥ III highest specificity for IH. Only ONSD reliably discriminated IH at baseline. Recanalization was significantly associated with regressive ONSD and pituitary grade. Other neuroimaging signs tended to regress with recanalization. After treatment, 184.9 ± 44.7 days after diagnosis, bulbar flattening resolved, whereas compared with controls ONSD enlargement (p < 0.001) and partially empty sella (p = 0.017), among other indicators, persisted. Conclusion: ONSD and pituitary grading have a high diagnostic value in diagnosing and monitoring CVT-associated IH. Given their limited sensitivity during early CVT and potentially persistent alterations following IH, neuroimaging indicators can neither replace CSF pressure measurement in diagnosing IH, nor determine the duration of anticoagulation.