Bernd Turowski’s research while affiliated with Universitätsklinikum Düsseldorf and other places

Background and Purpose Flow diversion has become a key treatment option for complex intracranial aneurysms. Recent advancements include coated flow diverters (FDs), designed to potentially reduce the need for dual antiplatelet therapy, thereby removing the associated secondary risks while maintaining patency and low complication rates. Comparing coated and uncoated FDs may offer insights into long‐term outcomes and treatment optimization. Method In this retrospective single‐center study, we investigated the data of 21 consecutive patients with cerebral aneurysms, treated between 2021 and 2023 with the coated Derivo 2heal Embolization Device and the uncoated Derivo Embolization Device (both Acandis). We described the procedure and analyzed clinical and radiological data, along with long‐term outcomes after 18 months of follow‐up. Results Nine patients (42.9%) had incidental, while 12 (57.1%) had symptomatic aneurysms, including 10 with World Federation of Neurosurgical Societies classification IV subarachnoid hemorrhages. Aneurysm locations included mostly the internal carotid ( n = 9) and the vertebral artery ( n = 7). All FDs were successfully deployed: 11 patients received the coated and 10 the uncoated device. After 18 months, 73.3% of patients had favorable outcomes (modified Rankin Score 0‐2). One coated FD occluded asymptomatically after 6 months, and one uncoated FD occluded immediately but could be recanalized. Conclusions We observed favorable occlusion rates for both coated and uncoated FDs. The role of dual antiplatelet therapy remains debated. Large multicenter studies are essential to evaluate the patency of coated compared to uncoated FDs and determine whether they can reduce thrombogenicity, potentially allowing for less or no antiplatelet therapy in emergencies.

Background The reduction of processing times in the treatment of acute ischemic stroke is of outstanding importance. Our objective is to analyze the acute stroke care chain from onset to treatment in a city in Germany comprising three stroke units. Additionally, we discuss solutions for detected treatment delays. Methods We conducted an in-depth analysis of acute stroke care processing times across three local stroke centers in Düsseldorf among all emergency services transportations for suspected stroke. Isochrone mapping was performed to identify areas with prolonged transportation times. Results Among the 1,714 transportations, 943 patients had confirmed strokes. Prehospital care constituted 58% of total emergency care time until imaging. Patients with confirmed stroke had reduced in-hospital times while patients receiving treatment experienced faster in-hospital times. Isochrone mapping revealed disparities in transportation times within the city. Conclusions In conclusion, we identified confirmation of stroke symptoms as pre- and in-hospital and treatment eligibility as in-hospital process accelerators in stroke care. We propose the introduction of an in-ambulance video consulting model to accelerate contact to stroke-experts and accelerate processing times for patients eligible for treatment. Furthermore, we discuss the combination of in-ambulance video consulting with imaging and starting treatment outside traditional stroke centers, followed by transportation to a stroke center during thrombolysis, which might further accelerate treatment in specific cases.

Background This multicenter study evaluated the safety and efficacy of coated flow diverters (cFDs) for the treatment of ruptured intracranial aneurysms. Methods Consecutive patients treated with different cFDs for ruptured aneurysms under tirofiban at eight neurovascular centers between 2016 and 2023 were retrospectively analyzed. The majority of patients were loaded with dual antiplatelet therapy after the treatment. Aneurysm occlusion was determined using the O'Kelly-Marotta (OKM) grading scale. Primary outcome measures were major procedural complications and aneurysmal rebleeding during hospitalization. Results The study included 60 aneurysms (posterior circulation: 28 (47%)) with a mean size of 5.8±4.7 mm. Aneurysm morphology was saccular in 28 (47%), blister-like in 12 (20%), dissecting in 13 (22%), and fusiform in 7 (12%). Technical success was 100% with a mean of 1.1 cFDs implanted per aneurysm. Adjunctive coiling was performed in 11 (18%) aneurysms. Immediate contrast retention was observed in 45 (75%) aneurysms. There was 1 (2%) major procedural complication (a major stroke, eventually leading to death) and no aneurysmal rebleeding. A good outcome (modified Rankin Scale 0–2) was achieved in 40 (67%) patients. At a mean follow-up of 6 months, 27/34 (79%) aneurysms were completely occluded (OKM D), 3/34 (9%) had an entry remnant (OKM C), and 4/34 (12%) had residual filling (OKM A or B). There was 1 (3%) severe in-stent stenosis during follow-up that was treated with balloon angioplasty. Conclusions Treatment of ruptured aneurysms with cFDs was reasonably safe and efficient and thus represents a valid treatment option, especially for complex cases.

Key Clinical Message T1‐weighted black blood FS sequences may provide a useful addition to imaging protocols in detection of subtle changes in venous vasculitides and, therefore, may have an impact on treatment options.

Gliomas with CDKN2A mutations are known to have worse prognosis but imaging features of these gliomas are unknown. Our goal is to identify CDKN2A specific qualitative imaging biomarkers in glioblastomas using a new informatics workflow that enables rapid analysis of qualitative imaging features with Visually AcceSAble Rembrandtr Images (VASARI) for large datasets in PACS. Sixty nine patients undergoing GBM resection with CDKN2A status determined by whole-exome sequencing were included. GBMs on magnetic resonance images were automatically 3D segmented using deep learning algorithms incorporated within PACS. VASARI features were assessed using FHIR forms integrated within PACS. GBMs without CDKN2A alterations were significantly larger (64 vs. 30%, p = 0.007) compared to tumors with homozygous deletion (HOMDEL) and heterozygous loss (HETLOSS). Lesions larger than 8 cm were four times more likely to have no CDKN2A alteration (OR: 4.3; 95% CI 1.5–12.1; p < 0.001). We developed a novel integrated PACS informatics platform for the assessment of GBM molecular subtypes and show that tumors with HOMDEL are more likely to have radiographic evidence of pial invasion and less likely to have deep white matter invasion or subependymal invasion. These imaging features may allow noninvasive identification of CDKN2A allele status.

Purpose Occlusions of the internal carotid artery (ICA) may be caused by dissection, embolic or macroangiopathic pathogenesis, which partially influences the treatment; however, inferring the underlying etiology in computed tomography angiography can be challenging. In this study, we investigated whether computed tomography perfusion (CT-P) parameters could be used to distinguish between etiologies. Methods Patients who received CT‑P in acute ischemic stroke due to ICA occlusion between 2012 and 2019 were retrospectively analyzed. Group comparisons between etiologies regarding the ratios of CT‑P parameters between both hemispheres for relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF), time to maximum (Tmax), and mean transit time (MTT) were calculated by one-factorial analysis of variance (ANOVA) and compared by pairwise Bonferroni post hoc tests. An receiver operating characteristics (ROC) analysis was performed if differences in group comparisons were found. Multinomial logistic regression (MLR) including pretherapeutic parameters was calculated for etiologies. Results In this study 69 patients (age = 70 ± 14 years, dissection = 10, 14.5%, embolic = 19, 27.5% and macroangiopathic = 40, 58.0%) were included. Group differences in ANOVA were only found for MTT ratio ( p = 0.003, η ² = 0.164). In the post hoc test, MTT ratio showed a differentiability between embolic and macroangiopathic occlusions ( p = 0.002). ROC analysis for differentiating embolic and macroangiopathic ICA occlusions based on MTT ratio showed an AUC of 0.77 ( p < 0.001, CI = 0.65–0.89) and a cut-off was yielded at a value of 1.15 for the MTT ratio (sensitivity 73%, specificity 68%). The MLR showed an overall good model performance. Conclusion It was possible to differentiate between patients with embolic and macroangiopathic ICA occlusions based on MTT ratios and to define a corresponding cut-off. Differentiation from patients with dissection versus the other etiologies was not possible by CT‑P parameters in our sample.

General microvascular perfusion and its heterogeneity are pathophysiological features of delayed cerebral ischemia (DCI) that are gaining increasing attention. Recently, CT perfusion (CTP) imaging has made it possible to evaluate them radiologically using mean transit time (MTT) and its heterogeneity (measured by cvMTT). This study evaluates the effect of multimodal rescue therapy (intra-arterial nimodipine administration and elevation of blood pressure) on MTT and cvMTT during DCI in aneurysmal subarachnoid haemorrhage (aSAH) patients. A total of seventy-nine aSAH patients who underwent multimodal rescue therapy between May 2012 and December 2019 were retrospectively included in this study. CTP-based perfusion impairment (MTT and cvMTT) on the day of DCI diagnosis was compared with follow-up CTP after initiation of combined multimodal therapy. The mean MTT was significantly reduced in the follow-up CTP compared to the first CTP (3.7 ± 0.7 s vs 3.3 ± 0.6 s; p < 0.0001). However, no significant reduction of cvMTT was observed (0.16 ± 0.06 vs 0.15 ± 0.06; p = 0.44). Mean arterial pressure was significantly increased between follow-up and first CTP (98 ± 17 mmHg vs 104 ± 15 mmHg; p < 0.0001). The combined multimodal rescue therapy was effective in addressing the general microvascular perfusion impairment but did not affect the mechanisms underlying microvascular perfusion heterogeneity. This highlights the need for research into new therapeutic approaches that also target these pathophysiological mechanisms of DCI.

BACKGROUND Gliomas with CDKN2A mutations are known to have worse prognosis but imaging features of these gliomas are unknown. Our goal is to identify CDKN2A specific qualitative imaging biomarkers in glioblastomas using a new informatics workflow that enables rapid analysis of qualitative imaging features with Visually AcceSAble Rembrandtr Images (VASARI) for large datasets in PACS. Gliomas with CDKN2A mutations are known to have worse prognosis but imaging features of these gliomas are unknown. Our goal is to identify CDKN2A specific qualitative imaging biomarkers in glioblastomas using a new informatics workflow that enables rapid analysis of qualitative imaging features withVisually AcceSAble Rembrandtr Images (VASARI) for large datasets in PACS. MATERIAL AND METHODS Sixty nine patients undergoing GBM resection with CDKN2A status determined by whole-exome sequencing were included. GBMs on magnetic resonance images were automatically 3D segmented using deep learning algorithmsincorporated within PACS. VASARI features were assessed using FHIR forms integrated within PACS. RESULTS GBMs without CDKN2A alterations were significantly larger (64% vs. 30%, p=0.007) compared to tumors with homozygous deletion (HOMDEL) and heterozygous loss (HETLOSS). Lesions larger than 8 cm were four times more likely to have no CDKN2A alteration (OR: 4.3; 95% CI:1.5-12.1; p<0.001). The pial invasion was predictive of HOMDEL (OR: 8.1, 95% CI: 1.8-53.2; p<0.012) as tumors with pial invasion were eight times more likely to be HOMDEL, even after adjusting for deep white matter and subependymal invasion. CONCLUSION We developed a novel integrated PACS informatics platform for the assessment of GBM molecular subtypes and show that tumors with HOMDEL are more likely to have radiographic evidence of pial invasion and less likely to have deep white matter invasion or subependymal invasion. These imaging features may allow noninvasive identification of CDKN2A allele status.

Introduction Early evidence suggests the safety of second- and third-generation intracranial stents in the treatment of intracranial aneurysms. Aim of Study This two-centre trial aims to directly compare the low-profile Acclino stent (Acandis) – a second-generation stent – with the first-generation Enterprise stent (Johnson & Johnson/Cerenovus). Methods Patients who received Enterprise or Acclino stents for unruptured aneurysms were followed for 8 years. Complications, clinical and angiographic outcomes were compared with the primary outcomes of ischaemic stroke incidence and mid-term occlusion rate. Propensity score adjustment adjusted for group differences. Results Both Enterprise and Acclino stents were used in the same number of cases (48 each). The analysis showed a higher incidence of thromboembolic complications in the Enterprise group (20.8% vs. 4.2%, HR: 6.6, 95%CI: 2.2–20.0, p=0.01, adjusted p<0.01) and a higher rate of major ischaemic stroke (6.3% vs. 0%, HR: 2.1, 95%CI: 1.8–2.4, p=0.08, adjusted p<0.01). However, there were no significant differences in mid-term or long-term angiographic outcomes, with procedural success rates of 83.3% and 75.0% for Enterprise and 89.2% and 75.9% for Acclino (both p>0.05). Retreatment rates were 10.4% in the Enterprise group and 4.2% in the Acclino group (p=0.42, adjusted p=0.10). Conclusion Advanced stents offer reduced thromboembolic risk and comparable aneurysm occlusion to first-generation stents due to their flexible design and surface modification. These results support the clinical use of advanced stent systems, but further comparative studies are needed to conclusively evaluate the efficacy of stent-assisted coiling with the Acclino stent and other systems. Disclosure of Interest CK serves as consultants for Acandis GmbH (Pforzheim, Germany) and proctor for MicroVention Inc./Sequent Medical (Aliso Viejo, CA, USA). David Zopfs is on the speaker’s bureau of Philips (Amsterdam, the Netherlands) and lecturer for Amboss GmbH (Cologne, Germany). The other authors declare that they have no competing interests.