Jens Fiehler

University of Hamburg | UHH · Department of Diagnostic and Interventional Neuroradiology

Background Isolated anterior cerebral artery occlusions (ACAo) in patients with acute ischemic stroke present significant challenges due to their rarity. The efficacy and safety of endovascular therapy (EVT) in comparison with best medical therapy (BMT) for ACAo remains unclear. This study aimed to assess the outcomes of these treatments. Methods...

Background Blood-brain barrier (BBB) leakage measured with dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) has been associated with hemorrhagic transformation in acute ischemic stroke (AIS). However, the influence of pre-thrombolysis BBB leakage on infarct growth has not been studied. Therefore, we aimed to characterize BBB int...

BACKGROUND The EXCELLENT registry aimed to evaluate the effectiveness of the EMBOTRAP Revascularization Device in an all-comer population in a real-world setting, with a focus on the composition of retrieved clots. METHODS EXCELLENT is a prospective, global registry of patients with acute ischemic stroke treated with EMBOTRAP as the first-line mec...

Overweight/obese patients experience a lower incidence of subarachnoid hemorrhage (SAH) compared to non-overweight patients, even though elevated body mass index (BMI) has been associated with various SAH risk factors. Given that intracranial aneurysms are a primary cause of SAH, a potential protective effect of a high BMI on intracranial aneurysms...

Background Despite the proven effectiveness of endovascular therapy (EVT) in acute ischemic strokes (AIS) involving anterior circulation large vessel occlusions, isolated posterior cerebral artery (PCA) occlusions (iPCAo) remain underexplored in clinical trials. This study investigates the comparative effectiveness and safety of EVT against medical...

Background and purpose Mechanical thrombectomy (MT) has revolutionized the prognosis of acute ischemic stroke. Indications for MT are constantly expanding across countries, presenting healthcare professionals, and institutions with the challenge of offering MT to the entire population despite geographic constraints, while also training enough inter...

Background: The study aimed to compare outcomes of mechanical thrombectomy (MT) in pediatric patients with acute ischemic stroke (AIS) caused by focal cerebral arteriopathy (FCA) versus cardioembolism (CE). Methods: Data from the Save ChildS and KidClot cohorts were merged. Children with AIS because of FCA or CE that underwent MT were included....

Background Recent advances have highlighted the efficacy of endovascular thrombectomy (EVT) in patients with large ischemic core stroke, yet a significant portion still experience very poor outcomes, defined as a 90-day modified Rankin Score (mRS) of 5–6. This study aims to investigate the hypoperfusion intensity ratio (HIR) as a prognostic imaging...

Purpose Since perfusion imaging may be unavailable in smaller hospitals, alternative imaging selection methods for acute ischemic stroke can improve outcomes and optimize resources. This study assessed the safety and effectiveness of using imaging criteria other than DEFUSE 3 and DAWN for thrombectomy beyond 6 h from symptom onset in patients strok...

Background The pipeline embolization device (PED) has been increasingly used to treat brain aneurysms; however, concerns have been raised about braid stability with newer drawn filled tubing technology devices. Objective To evaluate braid stability of PED early generations using data from the PREMIER trial. Methods All consecutive intracranial an...

Purpose To develop and evaluate an automated segmentation and classification tool for the discrimination of neoplastic and non-neoplastic intracerebral hemorrhage (ICH) on admission Computed Tomography (CT) utilizing images containing hemorrhage and perihematomal edema. Materials and Methods The models were developed and evaluated using a retrospe...

Background Successful recanalization defined as modified Thrombolysis in Cerebral Infarction Score (mTICI) ≥2b is not achieved in 15%–20% of patients with acute ischemic stroke. This study aims to identify patient-specific factors associated with early stopping without successful recanalization. We hypothesized that the probability of the decision...

Background Mechanical thrombectomy is a cornerstone treatment for acute ischemic stroke (AIS) with large vessel occlusion (LVO), yet the optimal technique remains debated. The SOFIA/SOFIA PLUS catheter has emerged as a promising tool for direct aspiration thrombectomy. Purpose This prospective multi-center study, adhering Good-Clinical-Practice gu...

Background The aim of this study is to assess the feasibility of identifying the hemodynamic status of intracranial atherosclerotic stenosis (ICAS) using angio-based fractional flow (FF) calculated from a single angiographic view, with wire-based FF as the reference standard. Method The study retrospectively recruited 100 ICAS patients who underwe...

Background and purpose: The management of acute ischemic stroke (AIS) due to distal medium vessel occlusion (DMVO) remains uncertain, particularly in comparing the effectiveness of intravenous thrombolysis (IVT) plus mechanical thrombectomy (MT) versus IVT alone. This study aimed to evaluate the safety and efficacy in DMVO patients treated with ei...

Background Medium vessel occlusion (MeVO) strokes, particularly affecting the M2 segment of the middle cerebral artery, represent a critical proportion of acute ischemic strokes, posing significant challenges in management and outcome prediction. The efficacy of mechanical thrombectomy (MT) in MeVO stroke may warrant reliable predictors of function...

Introduction While several risk factors for unruptured intracranial aneurysm (UIA) are known, the impact of the socioeconomic status (SES) on UIA incidence remains uncertain. Aim of Study This study aimed to investigate the association between SES and UIA while correcting for known confounding risk factors. Methods Retrospective analysis of subje...

Introduction Cerebral vasospasms (CV) remain a significant predictor of poor outcome after aneurysmal subarachnoid hemorrhage (aSAH). Aim of Study This study aims to analyze patients’ individual risk factors, intensity and extend of CV associated with poor functional outcome after aSAH. Methods We conducted a retrospective study of consecutive pa...

Introduction Boundaries of mechanical thrombectomy are continuously expanding, the TENSION trial[1] showed efficiency and safety in low ASPECTS patients, ongoing trials (ENDOLOW, MOSTE) investigate patients with low NIHSS[2]. Aim of Study To analyze treatment effects for stroke collectives stratified by NIHSS at admission and ASPECTS based on larg...

Introduction The interplay between thrombectomy-related infarct volume reduction, post-acute neurological improvement and functional outcome has been described[1-4]. However, pathophysiological mechanisms might be different in patients with large established infarcts. Aim of Study To evaluate how much of the thrombectomy-related treatment effect i...

Introduction The beneficial effect of endovascular treatment (EVT) on functional outcome in patients with ischemic stroke and low ASPECTS has recently been demonstrated. ASPECTS rating is based on the presence of ischemic lesion hypodensity, however the degree of hypoattenuation, directly indicating net water uptake (NWU), has not been considered f...

Introduction The EYMINT e-fellowship was launched in 2020 to foster neurointerventional training and has since enrolled 98 fellows to remotely observe cases by telestreaming. Evaluation identified the fixed allocation of a fellow and mentor as limiting factor to reach a sufficient case load. The program has therefore been modified to expose fellows...

Introduction Randomized trials have established endovascular thrombectomy (EVT) as an effective treatment for reducing disability in large ischemic strokes, yet the impact of arterial collateral status remains uncertain. Aim of Study The study aimed to explore whether the status of arterial collaterals alters the efficacy of EVT in patients experi...

Introduction Randomized trials provided evidence that thrombectomy is beneficial in stroke patients treated in the late time window (LTW), however, further insights of this subgroup remain limited. Aim of Study To investigate effects of etiology on outcomes in stroke patients treated with thrombectomy in the extended time window. Methods Availabl...

Introduction Endovascular coiling is commonly utilized for treating intracranial aneurysms, though it can sometimes result in complications such as displacement or thrombosis. This report discusses a unique case of spontaneous and beneficial thrombosis of a saccular unruptured aneurysm of the superior cerebellar artery (SUCA) during attempted endov...

Introduction Thrombectomy is of benefit for patients with large ischemic core, but inclusion in recent trials was based on different imaging criteria utilizing MRI, perfusion imaging, and/or non-enhanced CT (NECT) Aim of Study The purpose of this study was to directly compare the agreement of different ASPECTS rating methods according to the basel...

Introduction Artisse has several advantages: An atraumatic distal tip that protects the intracranial aneurysm (IA) dome during deployment, proximal and distal marker bands offer enhanced device visibility for ease of use, a dual-layer mesh basket provides a balance of radial force and conformability for a secure fit and a flared shape helps the dev...

Introduction Recent RCTs provided evidence that patients with established large infarcts benefit from thrombectomy.[1, 2] However, the effect of the achieved reperfusion level on functional outcome and whether unsuccessful thrombectomy is associated with worse prognosis compared to best medical treatment (BMT) has not been investigated in detail....

Introduction Successful recanalization by mechanical thrombectomy improves functional outcome of patients with ischemic stroke. However, infarct volume at 24h only partly explains long-term functional outcome [1-4]. Aim of Study A better understanding of the interplay between thrombectomy-related infarct volume reduction and post-acute rehabilitat...

Introduction Managing blood pressure in patients with large vessel occlusion affects infarct size and clinical outcomes. We examined how restoring blood flow impacts systemic blood pressure during mechanical thrombectomy. Patients and Methods Patients with large vessel occlusion in the anterior circulation undergoing mechanical thrombectomy betwee...

Background Deep venous outflow (VO) may be an important surrogate marker of collateral blood flow in acute ischemic stroke patients with a large vessel occlusion (AIS-LVO). Researchers have yet to determine the relationship between deep VO status in late-window patients and imaging measures of collaterals, which are key in preserving tissue. Mater...

Purpose To evaluate a nnU-Net-based deep learning for automated segmentation of intracerebral hemorrhage (ICH), intraventricular hemorrhage (IVH), and perihematomal edema (PHE) on noncontrast CT scans. Materials and Methods Retrospective data from acute ICH patients admitted at four European stroke centers (2017-2019), along healthy controls (2022...

Introduction Endovascular thrombectomy stands as a pivotal component in the standard care for patients experiencing acute ischemic stroke with large vessel occlusion. Subsequent care for patients often extends to a neurological intensive care unit. While fluid management is integral to intensive care, the association between early fluid balance and...

Background The combination of intravenous thrombolysis (IVT) with mechanical thrombectomy (MT) may have clinical benefits for patients with medium vessel occlusion. Purpose To examine whether MT combined with IVT is associated with different outcomes than MT alone in patients with acute ischemic stroke (AIS) and medium vessel occlusion. Materials a...

Importance Randomized clinical trials have demonstrated the efficacy and safety of endovascular thrombectomy for acute ischemic stroke with large infarct. Patients older than 80 years with large infarct are commonly encountered in clinical practice but underrepresented in randomized clinical trials. Objective To provide an age-based analysis of fu...

Objectives Medical devices based on X-ray imaging, such as computed tomography, are considered notable sources of artificial radiation. The aim of this study was to compare the computed tomography dose volume index, the dose length product, and the effective dose of the brain non-contrast enhanced examination on two CT scanners to determine the cur...

Background Acute ischemic stroke (AIS) from primary medium vessel occlusions (MeVO) is a prevalent condition associated with substantial morbidity and mortality. Despite the common use of mechanical thrombectomy (MT) in AIS, predictors of poor outcomes in MeVO remain poorly characterized. Methods In this prospectively collected, retrospectively re...

The increasing global life expectancy brings forth challenges associated with age-related cognitive and motor declines. To better understand underlying mechanisms, we investigated the connection between markers of biological brain aging based on magnetic resonance imaging (MRI), cognitive and motor performance, as well as modifiable vascular risk f...

Background The efficacy of endovascular treatment (EVT) in acute ischaemic stroke due to distal medium vessel occlusion (DMVO) remains uncertain. Our study aimed to evaluate the safety and efficacy of EVT compared with the best medical management (BMM) in DMVO. Methods In this prospectively collected, retrospectively reviewed, multicentre cohort s...

The aim of the present European Stroke Organisation (ESO) guideline is to provide evidence-based recommendations on the acute management of patients with basilar artery occlusion (BAO). These guidelines were prepared following the Standard Operational Procedure of the ESO and according to the GRADE methodology. Although BAO accounts for only 1–2% o...

Background A sizeable proportion of stroke patients with large vessel occlusion present with minor neurological deficits. Whether mechanical thrombectomy (MT) is beneficial in these patients is controversial. We aimed to investigate factors of early neurological deterioration (END) in thrombectomy patients with minor stroke and hypothesized that EN...

Background and purpose: Neuronal ceroid lipofuscinoses (NCL) are a group of neurodegenerative disorders. Recently, enzyme replacement therapy (ERT) was approved for CLN2, a subtype of NCL. The aim of this study was to quantify brain volume loss in CLN2 disease of patients on ERT in comparison to a natural history cohort using magnetic resonance im...

Background Acute ischemic stroke (AIS) caused by distal medium vessel occlusions (DMVOs) represents a significant proportion of overall stroke cases. While intravenous thrombolysis (IVT) has been a primary treatment, advancements in endovascular procedures have led to increased use of mechanical thrombectomy (MT) in DMVO stroke patients. However, s...

Background While mechanical thrombectomy is considered standard of care for large vessel occlusions, scientific evidence to support treatment for distal and medium vessel occlusions remains scarce. Purpose To evaluate feasibility, safety, and outcomes in patients with low National Institute of Health Stroke Scale scores undergoing mechanical throm...

Background CT perfusion (CTP)-derived baseline ischemic core volume (ICV) can overestimate the true extent of infarction, which may result in exclusion of patients with ischemic stroke from endovascular treatment (EVT). Purpose To determine whether ischemic core overestimation is associated with larger ICV and degree of recanalization. Materials an...

Background There is yet no randomized controlled evidence that mechanical thrombectomy (MT) is superior to best medical treatment in patients with large vessel occlusion but minor stroke symptoms (National Institutes of Health Stroke Scale [NIHSS] <6). Prior studies of patients with admission NIHSS scores >6 observed unfavorable functional outcomes...

Background Multiple studies and meta-analyses have described the technical and clinical outcomes in large cohorts of aneurysm patients treated with flow diverters (FDs). Variations in evaluation methodology complicate making comparisons among studies, hinder understanding of the device behavior, and pose an obstacle in the assessment of further adv...

Background Hematoma volume is a major pathophysiological hallmark of acute intracerebral hemorrhage (ICH). We investigated how the variance in functional outcome induced by the ICH volume is explained by neurological deficits at admission using a mediation model. Methods Patients with acute ICH treated in three tertiary stroke centers between Janu...

Background Intrasaccular devices have become increasingly popular in the treatment of cerebral aneurysms, particularly at the bifurcation. Here we evaluate the Contour Neurovascular System, an intrasaccular device for the endovascular treatment of cerebral aneurysms, in a multicenter cohort study, the largest to the best of our knowledge. Methods...

The aim of the present European Stroke Organisation (ESO) guideline is to provide evidence-based recommendations on the acute management of patients with basilar artery occlusion (BAO). These guidelines were prepared following the Standard Operational Procedure of the ESO and according to the GRADE methodology. Although BAO accounts for only 1-2% o...

Background: Stroke remains a major health concern globally, with oral anticoagulants widely prescribed for stroke prevention. The efficacy and safety of mechanical thrombectomy (MT) in anticoagulated patients with distal medium vessel occlusions (DMVO) are not well understood. Methods: This retrospective analysis involved 1282 acute ischemic stroke...

Background Optimal anesthetic strategy for the endovascular treatment of stroke is still under debate. Despite scarce data concerning anesthetic management for medium and distal vessel occlusions (MeVOs) some centers empirically support a general anesthesia (GA) strategy in these patients. Methods We conducted an international retrospective study...

Purpose Randomized controlled trials (RCTs) demonstrated a treatment effect of endovascular thrombectomy in acute ischemic stroke with large infarct, commonly defined as an Alberta Stroke Program Early CT Score (ASPECTS) of 3–5. However, data on endovascular thrombectomy in patients with very low ASPECTS of 0–2 remain scarce. Methods We conducted...

Purpose The Alberta Stroke Program Early CT Score (ASPECTS) is regularly used to guide patient selection for mechanical thrombectomy (MT). Similarly, penumbral imaging based on computed tomography perfusion (CTP) may serve as neuroimaging tool to guide treatment. Yet, patients with a large ischemic core on CTP may show only minor ischemic changes r...

The expanded Thrombolysis in Cerebral Infarction (eTICI) scale is the default method to measure reperfusion success of endovascular treatment for acute ischemic stroke. It is an estimate of the percentage of the vascular territory affected by the initial occlusion, or target downstream territory (TDT), that is reperfused after the intervention. Tra...

Objectives Ischemic edema is associated with worse clinical outcomes, especially in large infarcts. Computed tomography (CT)–based densitometry allows direct quantification of absolute edema volume (EV), which challenges indirect biomarkers like midline shift (MLS). We compared EV and MLS as imaging biomarkers of ischemic edema and predictors of ma...

Background A direct aspiration first pass technique (ADAPT) is an effective alternative to stent retriever thrombectomy for patients with large vessel occlusion (LVO). The PERFECT study evaluated direct aspiration with the EMBOVAC large bore aspiration catheter in patients with LVO strokes. Methods PERFECT was a prospective, post-market, single-ar...

Rationale Meta-analyses of case series of non-arteritic central retinal artery occlusion (CRAO) indicate beneficial effects of intravenous thrombolysis when initiated early after symptom onset. Randomized data is lacking to address this question. Aims REVISION investigates intravenous alteplase within 4.5 hours of monocular vision loss due to acut...

BACKGROUND Computed tomography perfusion (CTP) imaging is regularly used to guide patient selection for mechanical thrombectomy (MT). However, the effect of MT in patients without salvageable tissue on CTP has not been investigated. The purpose of this study was to assess the effect of MT in patients with stroke without perfusion mismatch profiles....

The link between metabolic syndrome (MetS) and neurodegenerative as well as cerebrovascular conditions holds substantial implications for brain health in at-risk populations. This study elucidates the complex relationship between MetS and brain health by conducting a comprehensive examination of cardiometabolic risk factors, brain morphology, and c...

Introduction In acute ischemic stroke, prediction of the tissue outcome after reperfusion can be used to identify patients that might benefit from mechanical thrombectomy (MT). The aim of this work was to develop a deep learning model that can predict the follow-up infarct location and extent exclusively based on acute single-phase computed tomogra...

We aimed to replicate recent findings on the association between the extent of cerebral small vessel disease (cSVD), functional brain network dedifferentiation, and cognitive impairment. We analyzed demographic, imaging, and behavioral data from the prospective population-based Hamburg City Health Study. Using a fully prespecified analysis pipeline...

Background: Mechanical thrombectomy (MT) has revolutionized the treatment of acute ischemic stroke (AIS) due to large vessel occlusion (LVO), but its efficacy and safety in medium vessel occlusion (MeVO) remain less explored. This multicenter, retrospective study aims to investigate the incidence and clinical outcomes of vessel perforations (confir...

The link between metabolic syndrome (MetS) and neurodegenerative as well cerebrovascular conditions holds substantial implications for brain health in at-risk populations. This study elucidates the complex relationship between MetS and brain health by conducting a comprehensive examination of cardiometabolic risk factors, cortical morphology, and c...

Purpose Our purpose was to assess the efficacy and safety of the pRESET LITE stent retriever (Phenox, Bochum, Germany), designed for medium vessel occlusion (MeVO) in acute ischemic stroke (AIS) patients with a primary MeVO. Methods We performed a retrospective analysis of the MAD MT Consortium, an integration of prospectively maintained databases...

Net water uptake (NWU) is a quantitative imaging biomarker used to assess cerebral edema resulting from ischemia via Computed Tomography (CT)-densitometry. It serves as a strong predictor of clinical outcome. Nevertheless, NWU measurements on follow-up CT scans after mechanical thrombectomy (MT) can be affected by contrast staining. To improve the...

Case: Paroxysmal nocturnal hemoglobinuria (PNH) is an extremely rare bone marrow disorder caused by acquired mutations in the phosphatidylinositol glycan class A gene, which lead to a partial or total loss of the cellular complement regulators CD55 and CD59.[1] In addition to complement-mediated hemolysis and cytopenia, venous and arterial thrombos...

Ischemic lesion net water uptake (NWU) represents a quantitative imaging biomarker for cerebral edema in acute ischemic stroke. Data on NWU for distinct occlusion locations remain scarce, but might help to improve the prognostic value of NWU. In this retrospective multicenter cohort study, we compared NWU between patients with proximal large vessel...

Purpose Artificial intelligence (AI) has emerged as a transformative force in medical research and is garnering increased attention in the public consciousness. This represents a critical time period in which medical researchers, healthcare providers, insurers, regulatory agencies, and patients are all developing and shaping their beliefs and polic...

Determining the optimal transportation for each stroke patient is critically important to achieve the best possible outcomes. In border regions the next comprehensive stroke center may be just across an international border, but bureaucratic and financial hurdles may prevent a simple transfer to the next stroke center. We hypothesized that in regio...

Background and purpose: Cerebral vasospasm is a common complication of aneurysmal SAH and remains a risk factor for delayed cerebral ischemia and poor outcome. The interrater reliability of CTA in combination with CTP has not been sufficiently studied. We aimed to investigate the reliability of CTA alone and in combination with CTP in the detectio...

Introduction Kidney dysfunction (KD) is a risk factor for cerebrovascular events and has been shown to have a detrimental effect on outcome after stroke. We evaluated the influence of KD at admission and pre-existing diagnosis of chronic kidney disease (CKD) before thrombectomy for anterior circulation stroke on functional independence and mortalit...