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.

The Aortic Ductus Diverticulum-Innocent Bystander or Potential Source of Thromboembolic Stroke?

OBJECTIVE: Due to reversal blood flow in the diastolic phase, outpouchings at the aortic isthmus may carry the risk of thrombus formation and subsequent thromboembolism. The objective was to evaluate the association between aortic ductus diverticula (ADDs) and ischemic brain alterations in cerebral magnetic resonance imaging. METHODS: A retrospective analysis of 218 patients who received both a dedicated computed tomography angiography of the thoracic aorta and a brain magnetic resonance imaging was performed. Two radiologists independently reviewed all examinations for the presence of ADD as well as ischemic alterations of the brain. The association between this anatomical variant and ischemic brain alterations was evaluated by univariate and bivariate logistic regression analyses. RESULTS: ADDs were identified/present in 35 of 218 patients (16%). Ischemic brain alterations were found in 57% of patients (20/35) with an ADD and in 42% of the control group (77/183, P = 0.1). The presence of an ADD did not prove to be an independent risk factor for ischemic brain alterations after multivariate adjustment (odds ratio = 1.7, 95% confidence interval = 0.72-3.96, P = 0.225). CONCLUSIONS: In the present study, ADDs were not significantly associated with ischemic brain alterations. Therefore, ADDs seem to be an innocent bystander with respect to the pathogenesis of ischemic brain alterations.

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.

Primary Central Nervous System Lymphoma: Clinical Evaluation of Automated Segmentation on Multiparametric MRI Using Deep Learning.

BACKGROUND: Precise volumetric assessment of brain tumors is relevant for treatment planning and monitoring. However, manual segmentations are time-consuming and impeded by intra- and interrater variabilities. PURPOSE: To investigate the performance of a deep-learning model (DLM) to automatically detect and segment primary central nervous system lymphoma (PCNSL) on clinical MRI. STUDY TYPE: Retrospective. POPULATION: Sixty-nine scans (at initial and/or follow-up imaging) from 43 patients with PCNSL referred for clinical MRI tumor assessment. FIELD STRENGTH/SEQUENCE: T1 -/T2 -weighted, T1 -weighted contrast-enhanced (T1 CE), and FLAIR at 1.0, 1.5, and 3.0T from different vendors and study centers. ASSESSMENT: Fully automated voxelwise segmentation of tumor components was performed using a 3D convolutional neural network (DeepMedic) trained on gliomas (n = 220). DLM segmentations were compared to manual segmentations performed in a 3D voxelwise manner by two readers (radiologist and neurosurgeon; consensus reading) from T1 CE and FLAIR, which served as the reference standard. STATISTICAL TESTS: Dice similarity coefficient (DSC) for comparison of spatial overlap with the reference standard, Pearson's correlation coefficient (r) to assess the relationship between volumetric measurements of segmentations, and Wilcoxon rank-sum test for comparison of DSCs obtained in initial and follow-up imaging. RESULTS: The DLM detected 66 of 69 PCNSL, representing a sensitivity of 95.7%. Compared to the reference standard, DLM achieved good spatial overlap for total tumor volume (TTV, union of tumor volume in T1 CE and FLAIR; average size 77.16 ± 62.4 cm3 , median DSC: 0.76) and tumor core (contrast enhancing tumor in T1 CE; average size: 11.67 ± 13.88 cm3 , median DSC: 0.73). High volumetric correlation between automated and manual segmentations was observed (TTV: r = 0.88, P < 0.0001; core: r = 0.86, P < 0.0001). Performance of automated segmentations was comparable between pretreatment and follow-up scans without significant differences (TTV: P = 0.242, core: P = 0.177). DATA CONCLUSION: In clinical MRI scans, a DLM initially trained on gliomas provides segmentation of PCNSL comparable to manual segmentation, despite its complex and multifaceted appearance. Segmentation performance was high in both initial and follow-up scans, suggesting its potential for application in longitudinal tumor imaging. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2.

Fully Automated MR Detection and Segmentation of Brain Metastases in Non-small Cell Lung Cancer Using Deep Learning.

BACKGROUND: Non-small cell lung cancer (NSCLC) is the most common tumor entity spreading to the brain and up to 50% of patients develop brain metastases (BMs). Detection of BMs on MRI is challenging with an inherent risk of missed diagnosis. PURPOSE: To train and evaluate a deep learning model (DLM) for fully automated detection and 3D segmentation of BMs in NSCLC on clinical routine MRI. STUDY TYPE: Retrospective. POPULATION: Ninety-eight NSCLC patients with 315 BMs on pretreatment MRI, divided into training (66 patients, 248 BMs) and independent test (17 patients, 67 BMs) and control (15 patients, 0 BMs) cohorts. FIELD STRENGTH/SEQUENCE: T1 -/T2 -weighted, T1 -weighted contrast-enhanced (T1 CE; gradient-echo and spin-echo sequences), and FLAIR at 1.0, 1.5, and 3.0 T from various vendors and study centers. ASSESSMENT: A 3D convolutional neural network (DeepMedic) was trained on the training cohort using 5-fold cross-validation and evaluated on the independent test and control sets. Three-dimensional voxel-wise manual segmentations of BMs by a neurosurgeon and a radiologist on T1 CE served as the reference standard. STATISTICAL TESTS: Sensitivity (recall) and false positive (FP) findings per scan, dice similarity coefficient (DSC) to compare the spatial overlap between manual and automated segmentations, Pearson's correlation coefficient (r) to evaluate the relationship between quantitative volumetric measurements of segmentations, and Wilcoxon rank-sum test to compare the volumes of BMs. A P value <0.05 was considered statistically significant. RESULTS: In the test set, the DLM detected 57 of the 67 BMs (mean volume: 0.99 ± 4.24 cm3 ), resulting in a sensitivity of 85.1%, while FP findings of 1.5 per scan were observed. Missed BMs had a significantly smaller volume (0.05 ± 0.04 cm3 ) than detected BMs (0.96 ± 2.4 cm3 ). Compared with the reference standard, automated segmentations achieved a median DSC of 0.72 and a good volumetric correlation (r = 0.95). In the control set, 1.8 FPs/scan were observed. DATA CONCLUSION: Deep learning provided a high detection sensitivity and good segmentation performance for BMs in NSCLC on heterogeneous scanner data while yielding a low number of FP findings. Level of Evidence 3 Technical Efficacy Stage 2.

Improved diagnostic accuracy for ulnar-sided TFCC lesions with radial reformation of 3D sequences in wrist MR arthrography.

OBJECTIVES: Triangular fibrocartilage complex (TFCC) injuries frequently cause ulnar-sided wrist pain and can induce distal radioulnar joint instability. With its complex three-dimensional structure, diagnosis of TFCC lesions remains a challenging task even in MR arthrograms. The aim of this study was to assess the added diagnostic value of radial reformatting of isotropic 3D MRI datasets compared to standard planes after direct arthrography of the wrist. METHODS: Ninety-three patients underwent wrist MRI after fluoroscopy-guided multi-compartment arthrography. Two radiologists collectively analyzed two datasets of each MR arthrogram for TFCC injuries, with one set containing standard reconstructions of a 3D thin-slice sequence in axial, coronal and sagittal orientation, while the other set comprised an additional radial plane view with the rotating center positioned at the ulnar styloid. Surgical reports (whenever available) or radiological reports combined with clinical follow-up served as a standard of reference. In addition, diagnostic confidence and assessability of the central disc and ulnar-sided insertions were subjectively evaluated. RESULTS: Injuries of the articular disc, styloid and foveal ulnar attachment were present in 20 (23.7%), 10 (10.8%) and 9 (9.7%) patients. Additional radial planes increased diagnostic accuracy for lesions of the styloid (0.83 vs. 0.90; p = 0.016) and foveal (0.86 vs. 0.94; p = 0.039) insertion, whereas no improvement was identified for alterations of the central cartilage disc. Readers' confidence (p < 0.001) and assessability of the ulnar-sided insertions (p < 0.001) were superior with ancillary radial reformatting. CONCLUSIONS: Access to the radial plane view of isotropic 3D sequences in MR arthrography improves diagnostic accuracy and confidence for ulnar-sided TFCC lesions. KEY POINTS: • In multi-compartment arthrography of the wrist, ancillary radial plane view aids assessability of the foveal and styloid ulnar-sided insertions of the triangular fibrocartilage complex. • Assessment of peripheral TFCC injuries is more accurate with access to radial multiplanar reconstructions. • Additional radial planes provide greater diagnostic confidence.

Reduction of CT artifacts from cardiac implantable electronic devices using a combination of virtual monoenergetic images and post-processing algorithms.

OBJECTIVES: To evaluate the reduction of artifacts from cardiac implantable electronic devices (CIEDs) by virtual monoenergetic images (VMI), metal artifact reduction (MAR) algorithms, and their combination (VMIMAR) derived from spectral detector CT (SDCT) of the chest compared to conventional CT images (CI). METHODS: In this retrospective study, we included 34 patients (mean age 74.6 ± 8.6 years), who underwent a SDCT of the chest and had a CIED in place. CI, MAR, VMI, and VMIMAR (10 keV increment, range: 100-200 keV) were reconstructed. Mean and standard deviation of attenuation (HU) among hypo- and hyperdense artifacts adjacent to CIED generator and leads were determined using ROIs. Two radiologists qualitatively evaluated artifact reduction and diagnostic assessment of adjacent tissue. RESULTS: Compared to CI, MAR and VMIMAR ≥ 100 keV significantly increased attenuation in hypodense and significantly decreased attenuation in hyperdense artifacts at CIED generator and leads (p < 0.05). VMI ≥ 100 keV alone only significantly decreased hyperdense artifacts at the generator (p < 0.05). Qualitatively, VMI ≥ 100 keV, MAR, and VMIMAR ≥ 100 keV provided significant reduction of hyper- and hypodense artifacts resulting from the generator and improved diagnostic assessment of surrounding structures (p < 0.05). Diagnostic assessment of structures adjoining to the leads was only improved by MAR and VMIMAR 100 keV (p < 0.05), whereas keV values ≥ 140 with and without MAR significantly worsened diagnostic assessment (p < 0.05). CONCLUSIONS: The combination of VMI and MAR as well as MAR as a standalone approach provides effective reduction of artifacts from CIEDs. Still, higher keV values should be applied with caution due to a loss of soft tissue and vessel contrast along the leads. KEY POINTS: • The combination of VMI and MAR as well as MAR as a standalone approach enables effective reduction of artifacts from CIEDs. • Higher keV values of both VMI and VMIMAR at CIED leads should be applied with caution since diagnostic assessment can be hampered by a loss of soft tissue and vessel contrast. • Recommended keV values for CIED generators are between 140 and 200 keV and for leads around 100 keV.

Deep learning assistance increases the detection sensitivity of radiologists for secondary intracranial aneurysms in subarachnoid hemorrhage.

PURPOSE: To evaluate whether a deep learning model (DLM) could increase the detection sensitivity of radiologists for intracranial aneurysms on CT angiography (CTA) in aneurysmal subarachnoid hemorrhage (aSAH). METHODS: Three different DLMs were trained on CTA datasets of 68 aSAH patients with 79 aneurysms with their outputs being combined applying ensemble learning (DLM-Ens). The DLM-Ens was evaluated on an independent test set of 104 aSAH patients with 126 aneuryms (mean volume 129.2 ± 185.4 mm3, 13.0% at the posterior circulation), which were determined by two radiologists and one neurosurgeon in consensus using CTA and digital subtraction angiography scans. CTA scans of the test set were then presented to three blinded radiologists (reader 1: 13, reader 2: 4, and reader 3: 3 years of experience in diagnostic neuroradiology), who assessed them individually for aneurysms. Detection sensitivities for aneurysms of the readers with and without the assistance of the DLM were compared. RESULTS: In the test set, the detection sensitivity of the DLM-Ens (85.7%) was comparable to the radiologists (reader 1: 91.2%, reader 2: 86.5%, and reader 3: 86.5%; Fleiss κ of 0.502). DLM-assistance significantly increased the detection sensitivity (reader 1: 97.6%, reader 2: 97.6%,and reader 3: 96.0%; overall P=.024; Fleiss κ of 0.878), especially for secondary aneurysms (88.2% of the additional aneurysms provided by the DLM). CONCLUSION: Deep learning significantly improved the detection sensitivity of radiologists for aneurysms in aSAH, especially for secondary aneurysms. It therefore represents a valuable adjunct for physicians to establish an accurate diagnosis in order to optimize patient treatment.

Impact of the weekend effect on outcome after microsurgical clipping of ruptured intracranial aneurysms.

BACKGROUND: The "weekend effect" describes the assumption that weekend and/or on-call duty admission of emergency patients is associated with increased morbidity and mortality rates. For aneurysmal subarachnoid hemorrhage, we investigated, whether presentation out of regular working hours and microsurgical clipping at nighttime correlates with worse patient outcome. METHODS: This is a retrospective review of consecutive patients that underwent microsurgical clipping of an acutely ruptured aneurysm at our institution between 2010 and 2019. Patients admitted during (1) regular working hours (Monday-Friday, 08:00-17:59) and (2) on-call duty and microsurgical clipping performed during (a) daytime (Monday-Sunday, 08:00-17:59) and (b) nighttime were compared regarding the following outcome parameters: operation time, treatment-related complications, vasospasm, functional outcome, and angiographic results. RESULTS: Among 157 enrolled patients, 104 patients (66.2%) were admitted during on-call duty and 48 operations (30.6%) were performed at nighttime. Admission out of regular hours did not affect cerebral infarction (p = 0.545), mortality (p = 0.343), functional outcome (p = 0.178), and aneurysm occlusion (p = 0.689). Microsurgical clipping at nighttime carried higher odds of unfavorable outcome at discharge (OR: 2.3, 95%CI: 1.0-5.1, p = 0.039); however, there were no significant differences regarding the remaining outcome parameters. After multivariable adjustment, clipping at nighttime did not remain as independent prognosticator of short-term outcome (OR: 2.1, 95%CI: 0.7-6.2, p = 0.169). CONCLUSIONS: Admission out of regular working hours and clipping at nighttime were not independently associated with poor outcome. The adherence to standardized treatment protocols might mitigate the "weekend effect."

MRI Follow-up of Astrocytoma: Automated Coregistration and Color-Coding of FLAIR Sequences Improves Diagnostic Accuracy With Comparable Reading Time.

BACKGROUND: MRI follow-up is widely used for longitudinal assessment of astrocytoma, yet reading can be tedious and error-prone, in particular when changes are subtle. PURPOSE/HYPOTHESIS: To determine the effect of automated, color-coded coregistration (AC) of fluid attenuated inversion recovery (FLAIR) sequences on diagnostic accuracy, certainty, and reading time compared to conventional follow-up MRI assessment of astrocytoma patients. STUDY TYPE: Retrospective. POPULATION: In all, 41 patients with neuropathologically confirmed astrocytoma. FIELD STRENGTH/SEQUENCE: 1.0-3.0T/FLAIR ASSESSMENT: The presence or absence of tumor progression was determined based on FLAIR sequences, contrast-enhanced T1 sequences, and clinical data. Three radiologists assessed 47 MRI study pairs in a conventional reading (CR) and in a second reading supported by AC after 6 weeks. Readers determined the presence/absence of tumor progression and indicated diagnostic certainty on a 5-point Likert scale. Reading time was recorded by an independent assessor. STATISTICAL TESTS: The Wilcoxon test was used to assess reading time and diagnostic certainty. Differences in diagnostic accuracy, sensitivity, and specificity were analyzed with the McNemar mid-p test. RESULTS: Readers attained significantly higher overall sensitivity (0.86 vs. 0.75; P < 0.05) and diagnostic accuracy (0.84 vs. 0.73; P < 0.05) for detection of progressive nonenhancing tumor burden when using AC compared to CR. There was a strong trend towards higher specificity within the AC-augmented reading, yet without statistical significance (0.83 vs. 0.71; P = 0.08). Sensitivity for unequivocal disease progression was similarly high in both approaches (AC: 0.94, CR: 0.92), while for marginal disease progressions, it was significantly higher in AC (AC: 0.78, CR: 0.58; P < 0.05). Reading time including application loading time was comparable (AC: 38.1 ± 16.8 sec, CR: 36.0 ± 18.9 s; P = 0.25). DATA CONCLUSION: Compared to CR, AC improves comparison of FLAIR signal hyperintensity at MRI follow-up of astrocytoma patients, allowing for a significantly higher diagnostic accuracy, particularly for subtle disease progression at a comparable reading time. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY STAGE: 6 J. Magn. Reson. Imaging 2020;52:1197-1206.

Adjustment of Stent Retriever Length to Clot Extent Affects First-Pass Reperfusion in Endovascular Treatment of Acute Ischemic Stroke.

BACKGROUND: Stent retriever technology has evolved, and significantly longer devices have become available for mechanical thrombectomy (MT) of large cerebral vessel occlusions in ischemic stroke. We hypothesized that increased stent retriever length may improve the rate of complete angiographic reperfusion and decrease the respective number of attempts, resulting in a better clinical outcome. METHODS: Retrospective analysis of patients with large vessel occlusion in the anterior and posterior circulation treated with stent retriever MT. The study group was dichotomized into short (20 mm) and long (>20 mm) retrievers using propensity matching. In the anterior circulation, the clot burden score was evaluated. Primary end points were first-pass modified thrombolysis in cerebral infarction (mTICI) 3 reperfusion and first-pass mTICI ≥ 2b reperfusion, and the secondary end point was functional independence (defined as modified Rankin Scale score 0-2) at discharge and 90 days. RESULTS: Overall, 394 patients were included in the analysis. In the anterior circulation, short stent retrievers had a significantly higher rate of first-pass reperfusion in cases with low clot burden (mTICI 3: 27% vs. 17%; p = 0.009; mTICI ≥ 2b: 42 vs. 30%; p = 0.005) and in middle cerebral artery occlusions (mTICI ≥ 2b: 51 vs. 41%; p = 0.024). Higher rates of favorable outcome at discharge and 90 days were observed for the short stent retriever group (p < 0.001). CONCLUSION: Stent retriever length should be adjusted to clot burden score and vessel occlusion site.

Retreatment strategies for recurrent and residual aneurysms after treatment with flow-diverter devices.

PURPOSE: The management of residual or persistent intracranial aneurysms after flow-diversion therapy is not well defined in the literature. In this multicentric study, we report clinical and angiographic outcomes of 11 patients that underwent retreatment for 12 aneurysms initially treated with flow-diverter stents. METHODS: The median patient age was 53 years. Aneurysms (median size, 7.3 mm) were located at the internal carotid artery in 9 cases, and at the posterior circulation in 3. Treatment strategies, complications, and angiographic outcome were retrospectively assessed. RESULTS: Retreatment was feasible in all cases and performed by overlapping flow-diverter implantation. Overall, 12 side vessels were covered during retreatment, whereof 10 (83.3%) remained patent until mid-term follow-up. There were no further technical or symptomatic complications and no treatment-related morbidity. Angiographic follow-up (median, 17 months) showed improved aneurysm occlusion in all patients. Complete or near-complete aneurysm occlusion was achieved in 11 aneurysms (91.7%). CONCLUSION: Required retreatment after failed flow-diversion therapy can be performed with adequate safety and efficacy by placement of additional flow-diverter stents.

Flow-regulated versus differential pressure valves for idiopathic normal pressure hydrocephalus: comparison of overdrainage rates and neurological outcome.

BACKGROUND: To compare flow-regulated (FR) and differential pressure (DP) valves for treatment of patients with idiopathic normal hydrocephalus (iNPH) focusing on overdrainage and neurological outcome. METHODS: This is a retrospective study of patients with iNPH treated with FR and DP valves at a single institution between 2008 and 2018. The neurological status was evaluated retrospectively with the Kiefer scale at baseline, after shunt placement and at the 6-month follow-up. Groups were compared using inverse probability of treatment weighting based on propensity scores. RESULTS: The study cohort consisted of 38 patients treated with FR valves and 49 with DP valves. The mean patient age was 72.0 ± 7.6 years. Based on the Kiefer scale score, neurological improvement at the 6-month follow-up was recorded in 79.6% in the DP group and 89.5% in the FR group (p = 0.252). The overdrainage rates were higher among DP valves (10.2%) than among FR valves (2.6%, adjusted p = 0.002). Valve malfunction occurred in 2.0% in the DP group and 5.3% in the FR group (adjusted p = 0.667). CONCLUSIONS: The current study demonstrates a comparable neurological improvement between DP and FR valves, with potentially lower overdrainage rates among FR valves. Long-term studies will be necessary to draw a definite conclusion on FR valves for treatment of iNPH patients.

Impact of aneurysm shape on morbidity after clipping of unruptured intracranial aneurysms.

BACKGROUND: Complex aneurysm shape is a predominant risk factor for aneurysm rupture but its impact on clinical outcome after clipping remains unclear. The objective of the present study was to compare complications and morbidity after clipping of unruptured single-sac aneurysms (SSAs) and aneurysms with multiple sacs (MSAs). METHODS: A retrospective, single-center study was conducted for patients that were treated between 2010 and 2018. We analyzed surgical parameters, treatment-related complications, and morbidity, defined as any increase in the modified Rankin scale at 3-month follow-up. RESULTS: We identified 101 patients (mean age: 52.9 ± 10.5 years) that underwent clipping for 57 SSAs and 44 MSAs. The two groups were comparable regarding aneurysm size and neck width. Clipping of MSAs was associated with a longer operation time (p = 0.008) and increased use of intraoperative indocyanine green (p = 0.016) than SSAs. Complications occurred more often in the MSA group (29.5%) than in the SSA group (14.0%; p = 0.057). Morbidity was significantly higher in the MSA group (20.5%) than in the SSA group (3.5%, p = 0.009). In the univariate analysis, the odds of morbidity were 7.1 times greater for MSAs than for SSAs (95% CI 1.4-34.7). CONCLUSIONS: Morbidity after microsurgical clipping is significantly increased in MSAs as compared to SSAs. This may be attributed to a more difficult clip placement with stronger manipulation of the aneurysm dome and the surrounding brain tissue.

von Willebrand factor fibers promote cancer-associated platelet aggregation in malignant melanoma of mice and humans.

Tumor-mediated procoagulatory activity leads to venous thromboembolism and supports metastasis in cancer patients. A prerequisite for metastasis formation is the interaction of cancer cells with endothelial cells (ECs) followed by their extravasation. Although it is known that activation of ECs and the release of the procoagulatory protein von Willebrand factor (VWF) is essential for malignancy, the underlying mechanisms remain poorly understood. We hypothesized that VWF fibers in tumor vessels promote tumor-associated thromboembolism and metastasis. Using in vitro settings, mouse models, and human tumor samples, we showed that melanoma cells activate ECs followed by the luminal release of VWF fibers and platelet aggregation in tumor microvessels. Analysis of human blood samples and tumor tissue revealed that a promoted VWF release combined with a local inhibition of proteolytic activity and protein expression of ADAMTS13 (a disintegrin-like and metalloproteinase with thrombospondin type I repeats 13) accounts for this procoagulatory milieu. Blocking endothelial cell activation by the low-molecular-weight heparin tinzaparin was accompanied by a lack of VWF networks and inhibited tumor progression in a transgenic mouse model. Our findings implicate a mechanism wherein tumor-derived vascular endothelial growth factor-A (VEGF-A) promotes tumor progression and angiogenesis. Thus, targeting EC activation envisions new therapeutic strategies attenuating tumor-related angiogenesis and coagulation.

Sellar Melanoma With Lung Metastasis: A Case Report.

We report the case of an 81-year-old patient with no pre-existing medical conditions who presented with a one-week history of progressive horizontal diplopia. Contrast-enhanced brain magnetic resonance imaging showed a heterogeneous sellar mass with the infiltration of the cavernous sinus and sella. Hormone levels were within normal limits. Considering an endocrine inactive pituitary adenoma, the patient underwent transsphenoidal resection. After surgery, the preoperative symptoms completely resolved. Histopathologic examination of the tumor specimen revealed melanoma. Since the patient had no history of cancer, an extensive staging workup was performed, which revealed multiple lung metastases. However, no primary tumor was found. We recommended adjuvant brain irradiation and chemo- and immunotherapy, but the patient refused further oncological treatment and died five months after surgery. Reported cases of sellar melanoma are rare, and the combination of sellar melanoma and lung metastasis without a cutaneous primary is unique. Although rare, malignant lesions of the sella must be considered in the differential diagnosis, especially in cases with rapid onset of symptoms.

Incidence and Clinical Presentation of Pre- and Postoperative Seizures in Patients With Posterior Fossa Meningiomas.

INTRODUCTION: Seizures are a common symptom of supratentorial meningiomas with pre- and postoperative seizure rates of approximately 30% and 12%, respectively, especially in parasagittal and convexity meningiomas. Less is known about the association between seizures and posterior fossa meningiomas. This study evaluates the prevalence, potential causes, and outcomes of seizures in patients who have undergone surgery for posterior fossa meningioma. METHODS: This is a retrospective, observational, single-center study of consecutive patients who underwent surgical resection of posterior fossa meningiomas between 2009 and 2017. We retrospectively identified patients with seizures and analyzed patient demographics, tumor characteristics, and procedural characteristics. RESULTS: A total of 44 patients (mean age: 59.8 ± 13.5 years) were included. Twenty-six tumors were located at the cerebellar convexity and tentorium (59.1%), 12 at the cerebellopontine angle (27.3%), four at the clivus (9.1%), and two at the foramen magnum (4.5%). Seizures were the presenting symptom of cerebellar meningioma in two patients. Patients were seizure-free after surgery. Three patients had their first seizure after surgery (interval between surgery and first seizure: two days to 17 months). Analysis of these three patients revealed possible causes of postoperative seizures: radiation necrosis and edema, hyponatremia, and preoperative hydrocephalus. In all patients with postoperative seizures, long-term seizure control was achieved with the administration of antiepileptic drugs. CONCLUSIONS: The incidence of seizures in patients with posterior fossa meningiomas is relatively low. Antiepileptic drugs can help to achieve seizure control.

Oversizing of the Woven EndoBridge for Treatment of Intracranial Aneurysms Improves Angiographic Results (WEBINAR).

OBJECTIVE: Several studies have demonstrated a high safety and efficacy profile of the Woven EndoBridge (WEB) for endovascular aneurysm treatment. However, contemporary large-scale studies of the WEB are rare. This multicenter study attempts to set a benchmark for state-of-the-art WEB treatment with consistent application of the WEB oversizing technique. METHODS: This is a retrospective, multicenter study of aneurysms (dome width 2-10 mm) treated with the WEB between 2015 and 2023. Patient and aneurysm characteristics, complications, and clinical and angiographic outcomes were analyzed. RESULTS: The study consisted of 247 patients treated for 251 aneurysms (25.5% ruptured, 5.6% recurrent). WEB implantation was feasible in 98.8%, achieving a mean WEB/dome ratio of 1.2 ± 0.1. The thromboembolic complication rate was 7.2%, which was higher in ruptured versus unruptured aneurysms (hazard ratio: 2.8, 95%CI: 1.0-7.6, P = 0.04), but lower in cases where WEB 17 was used (hazard ratio: 4.0, 95%CI: 1.4-11.2, P = 0.01). Neurological complications occurred in 8 procedures (3.2%), including 3 (1.2%) major, and 5 (2.0%) minor events. Procedural morbidity and mortality were 0.8% and 0%, respectively. Mid-term complete and adequate occlusion rates were 66.3% and 88.4%, respectively. The retreatment rate was 5.2%. Feasibility, complication, and occlusion rates were comparable between typical and atypical aneurysm locations. CONCLUSIONS: Oversizing the WEB and using currently available WEB types in this series resulted in slightly better treatment outcomes compared to early WEB studies, confirming the high safety, feasibility, and efficacy of this technique.

State-of-the-art mobile head CT scanner delivers nearly the same image quality as a conventional stationary CT scanner.

The use of mobile head CT scanners in the neurointensive care unit (NICU) saves time for patients and NICU staff and can reduce transport-related mishaps, but the reduced image quality of previous mobile scanners has prevented their widespread clinical use. This study compares the image quality of SOMATOM On.Site (Siemens Healthineers, Erlangen, Germany), a state-of-the-art mobile head CT scanner, and a conventional 64-slice stationary CT scanner. The study included 40 patients who underwent head scans with both mobile and stationary scanners. Gray and white matter signal and noise were measured at predefined locations on axial slices, and signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) were calculated. Artifacts below the cranial calvaria and in the posterior fossa were also measured. In addition, image quality was subjectively assessed by two radiologists in terms of corticomedullary differentiation, subcalvarial space, skull artifacts, and image noise. Quantitative measurements showed significantly higher image quality of the stationary CT scanner in terms of noise, SNR and CNR of gray and white matter. Artifacts measured in the posterior fossa were higher with the mobile CT scanner, but subcalvarial artifacts were comparable. Subjective image quality was rated similarly by two radiologists for both scanners in all domains except image noise, which was better for stationary CT scans. The image quality of the SOMATOM On.Site for brain scans is inferior to that of the conventional stationary scanner, but appears to be adequate for daily use in a clinical setting based on subjective ratings.