Endovascular treatment of unruptured intracranial aneurysms with flow diverters: A retrospective long-term single center analysis.

PURPOSE: The introduction of flow diverters (FDs) in 2007 greatly enhanced the treatment of intracranial aneurysms. Here, we present our long-term clinical experience in treating unruptured intracranial aneurysms with FDs. METHODS: 107 patients with unruptured aneurysms and treated with an FD between 2010 and 2019 were retrospectively reviewed. Aneurysm occlusion, procedural complications, and clinical outcome were evaluated. RESULTS: Angiographic follow-up was available for 93 patients with a mean long-term follow-up time of 28.4 ± 21.6 months. Additional coiling was performed in 15.1% of patients (n = 14). Adequate aneurysm occlusion (Kamran grades 3 and 4) at long-term follow-up was achieved in 94.6% of patients (n = 88). 3.2% (n = 3) required endovascular retreatment since the last follow-up showed a lack of aneurysm occlusion (Kamran grade 0) due to a foreshortening of the FD. Incomplete opening of the FD and parent vessel occlusion was seen in 1.1% (n = 1) and 3.2% (n = 3) of patients, respectively. In-stent stenosis was observed in 57% (n = 53) of cases at short-term follow-up and 22.6% (n = 21) at long-term, which were moderate and asymptomatic overall. In-stent stenosis decreased significantly between short- and long-term follow-ups (31.4 ± 17.0% vs 9.7 ± 13.6%, respectively; p ≤ 0.001). Thromboembolic and hemorrhagic events occurred in 7.5% (n = 7) and 1.1% (n = 1) of patients, respectively. Good clinical outcome (modified Rankin scale: 0-2) was obtained in 97.8% (n = 91) leading to an overall treatment-related morbidity of 2.2% (n = 2). There was no procedural mortality. CONCLUSION: Our study shows that FD treatment of unruptured intracranial aneurysms is effective and safe with high occlusion rates and low rates of permanent morbidity at long-term follow-up.

Treatment of Wide-Necked Cerebral Aneurysms Using the WEB Device Including Flow Alteration Assessment With Color-Coded Imaging: A Single Center Experience.

Objective: The Woven EndoBridge (WEB) device (MicroVention, Tustin, CA) has extended the treatment of cerebral aneurysms. Despite the fact that the WEB device has shown promising clinical results, little is known about the caused intra-aneurysmal flow alterations. Here we present our clinical experience with the WEB, including examining various syngo iFlow (Siemens AG, Erlangen, Germany) parameters to predict aneurysm occlusion. Methods: We reviewed the data from patients with unruptured cerebral aneurysms treated with a WEB device between 2016 and 2020. Aneurysm occlusion and complications were assessed. Furthermore, different quantitative criteria were evaluated using syngo iFlow after digital subtraction angiography. Results: A total of 26 patients hosting 26 cerebral aneurysms met the inclusion criteria. Follow-up was available for 21 patients, with a mean of 7.3 ± 6.3 months. A total of 71.4% (n = 15) of the aneurysms included were located in the anterior and 28.6% (n = 6) in the posterior circulation. Adequate aneurysm occlusion was achieved in 85.7% (n = 18). The iFlow parameters for reduced aneurysm outflow (ID-R) differed significantly from the parameters for reduced inflow (PI-R and PI-D) (P < 0.001). The parameters did not differ significantly between adequately and insufficiently occluded aneurysms. Only a trend towards a lower ID-R of insufficiently occluded aneurysms was observed (P = 0.063), indicating a potential predictive value for insufficient aneurysmal outflow. There was no treatment-related morbidity or mortality. Conclusions: The applied syngo iFlow parameters confirmed that flow changes induced by the WEB device significantly affect outflow compared to inflow and have potential predictive value for adequate aneurysm occlusion.

Effects of a Feedback-Demanding Stroke Clock on Acute Stroke Management: A Randomized Study.

BACKGROUND AND PURPOSE: This randomized study aimed to evaluate whether the use of a stroke clock demanding active feedback from the stroke physician accelerates acute stroke management. METHODS: For this randomized controlled study, a large-display alarm clock was installed in the computed tomography room, where admission, diagnostic work-up, and intravenous thrombolysis occurred. Alarms were set at the following target times after admission: (1) 15 minutes (neurological examination completed); (2) 25 minutes (computed tomography scanning and international normalized ratio determination by point-of-care laboratory completed); and (3) 30 minutes (intravenous thrombolysis started). The responsible stroke physician had to actively provide feedback by pressing a buzzer button. The alarm could be avoided by pressing the button before time out. Times to therapy decision (primary end point, defined as the end of all diagnostic work-up required for decision for or against recanalizing treatment), neurological examination, imaging, point-of-care laboratory, needle, and groin puncture were assessed by a neutral observer. Functional outcome (modified Rankin Scale) was assessed at day 90. RESULTS: Of 107 participants, 51 stroke clock patients exhibited better stroke-management metrics than 56 control patients. Times from door to (1) end of all indicated diagnostic work-up (treatment decision time; 16.73 versus 26.00 minutes, P<0.001), (2) end of neurological examination (7.28 versus 10.00 minutes, P<0.001), (3) end of computed tomography (11.17 versus 14.00 minutes, P=0.002), (4) end of computed tomography angiography (14.00 versus 17.17 minutes, P=0.001), (5) end of point-of-care laboratory testing (12.14 versus 20.00 minutes, P<0.001), and (6) needle times (18.83 versus 47.00 minutes, P=0.016) were improved. In contrast, door-to-groin puncture times and functional outcomes at day 90 were not significantly different. CONCLUSIONS: This study showed that the use of a stroke clock demanding active feedback significantly improves acute stroke-management metrics and, thus, represents a potential low-cost strategy for streamlining time-sensitive stroke treatment.

[Woven-EndoBridge (WEB) as an intrasaccular method of aneurysm occlusion]. / Woven EndoBridge (WEB) als intrasakkuläre Methode des Aneurysmaverschlusses.

CLINICAL PROBLEM: The treatment of intracranial wide-necked bifurcation aneurysms-which account for approximately 26-36% of all brain aneurysms-can be challenging both endovascularly and surgically, as a complete cut-off of the blood flow into the aneurysm should be achieved without disruption of the flow into the bifurcation vessels. Intrasacular flow disruption with the Woven-EndoBridge (WEB) is an innovative technique for the treatment of such aneurysms. This review article discusses various aspects of the treatment of intracranial aneurysms with the WEB device, including indications, aneurysm/device selecting strategies, antiplatelet therapy requirements, procedural technique and potential complications. PRACTICAL RECOMMENDATIONS: Intrasacular flow disruption with the WEB device is a safe and effective treatment method for intracranial wide-necked bifurcation aneurysms, especially for patients with ruptured aneurysms, in patients with contraindications for antiplatelet therapy, and for patients in whom clipping is associated with high risks.

Why we fail: mechanisms and co-factors of unsuccessful thrombectomy in acute ischemic stroke.

PURPOSE: Mechanical thrombectomy (MT) is an effective treatment for patients suffering from acute ischemic stroke. However, recanalization fails in about 16.5% of interventions. We report our experience with unsuccessful MT and analyze technical reasons plus patient-related parameters for failure. METHODS: Five hundred ninety-six patients with acute ischemic stroke in the anterior circulation and intention to perform MT with an aspiration catheter and/or stent retriever were analyzed. Failure was defined as 0, 1, or 2a on the mTICI scale. Patients with failing MT were analyzed for interventional progress and compared to patients with successful intervention, whereby parameters included demographics, medical history, stroke presentation, and treatment. RESULTS: One hundred of the 596 (16.8%) interventions failed. In 20 cases, thrombus could not be accessed or passed with the device. Peripheral arterial occlusive disease is common in those patients. In 80 patients, true stent retriever failure occurred. In this group, coagulation disorders are associated with poor results, whereas atrial fibrillation is associated with success. The administration of intravenous thrombolysis and intake of nitric oxide donors are associated with recanalization success. Intervention duration was significantly longer in the failing group. CONCLUSION: In 20% of failing MT, thrombus cannot be reached/passed. Direct carotid puncture or surgical arterial access could be considered in these cases. In 80% of failing interventions, thrombus can be passed with the device, but the occluded vessel cannot be recanalized. Rescue techniques can be an option. Development of new devices and techniques is necessary to improve recanalization rates. Assessment of pre-existing illness could sensitize for occurring complications.

Prehospital Stroke Management Optimized by Use of Clinical Scoring vs Mobile Stroke Unit for Triage of Patients With Stroke: A Randomized Clinical Trial.

Importance: Transferring patients with large-vessel occlusion (LVO) or intracranial hemorrhage (ICH) to hospitals not providing interventional treatment options is an unresolved medical problem. Objective: To determine how optimized prehospital management (OPM) based on use of the Los Angeles Motor Scale (LAMS) compares with management in a Mobile Stroke Unit (MSU) in accurately triaging patients to the appropriate hospital with (comprehensive stroke center [CSC]) or without (primary stroke center [PSC]) interventional treatment. Design, Setting, and Participants: In this randomized multicenter trial with 3-month follow-up, patients were assigned week-wise to one of the pathways between June 15, 2015, and November 15, 2017, in 2 regions of Saarland, Germany; 708 of 824 suspected stroke patients did not meet inclusion criteria, resulting in a study population of 116 adult patients. Interventions: Patients received either OPM based on a standard operating procedure that included the use of the LAMS (cut point ≥4) or management in an MSU (an ambulance with vascular imaging, point-of-care laboratory, and telecommunication capabilities). Main Outcomes and Measures: The primary end point was the proportion of patients accurately triaged to either CSCs (LVO, ICH) or PSCs (others). Results: A predefined interim analysis was performed after 116 patients of the planned 232 patients had been enrolled. Of these, 53 were included in the OPM group (67.9% women; mean [SD] age, 74 [11] years) and 63 in the MSU group (57.1% women; mean [SD] age, 75 [11] years). The primary end point, an accurate triage decision, was reached for 37 of 53 patients (69.8%) in the OPM group and for 63 of 63 patients (100%) in the MSU group (difference, 30.2%; 95% CI, 17.8%-42.5%; P < .001). Whereas 7 of 17 OPM patients (41.2%) with LVO or ICH required secondary transfers from a PSC to a CSC, none of the 11 MSU patients (0%) required such transfers (difference, 41.2%; 95% CI, 17.8%-64.6%; P = .02). The LAMS at a cut point of 4 or higher led to an accurate diagnosis of LVO or ICH for 13 of 17 patients (76.5%; 6 triaged to a CSC) and of LVO selectively for 7 of 9 patients (77.8%; 2 triaged to a CSC). Stroke management metrics were better in the MSU group, although patient outcomes were not significantly different. Conclusions and Relevance: Whereas prehospital management optimized by LAMS allows accurate triage decisions for approximately 70% of patients, MSU-based management enables accurate triage decisions for 100%. Depending on the specific health care environment considered, both approaches are potentially valuable in triaging stroke patients. Trial Registration: ClinicalTrials.gov identifier: NCT02465346.

Prehospital Computed Tomography Angiography in Acute Stroke Management.

BACKGROUND: An ambulance equipped with a computed tomography (CT) scanner, a point-of-care laboratory, and telemedicine capabilities (mobile stroke unit [MSU]) has been shown to enable the delivery of thrombolysis to stroke patients directly at the emergency site, thereby significantly decreasing time to treatment. However, work-up in an MSU that includes CT angiography (CTA) may also potentially facilitate triage of patients directly to the appropriate target hospital and specialized treatment, according to their individual vascular pathology. METHODS: Our institution manages a program investigating the prehospital management of patients with suspicion of acute stroke. Here, we report a range of scenarios in which prehospital CTA could be relevant in triaging patients to the appropriate target hospital and to the individually required treatment. RESULTS: Prehospital CTA by use of an MSU allowed to detect large vessel occlusion of the middle cerebral artery in one patient with ischemic stroke and occlusion of the basilar artery in another, thereby allowing rational triage to comprehensive stroke centers for immediate intra-arterial treatment. In complementary cases, prehospital imaging not only allowed diagnosis of parenchymal hemorrhage with a spot sign indicating ongoing bleeding in one patient and of subarachnoid hemorrhage in another but also clarified the underlying vascular pathology, which was relevant for subsequent triage decisions. CONCLUSION: Defining the vascular pathology by CTA directly at the emergency site may be beneficial in triaging patients with various cerebrovascular diseases to the most appropriate target hospital and specialized treatment.

First Automated Stroke Imaging Evaluation via Electronic Alberta Stroke Program Early CT Score in a Mobile Stroke Unit.

BACKGROUND: Recently, a mobile stroke unit (MSU) was shown to facilitate acute stroke treatment directly at the emergency site. The neuroradiological expertise of the MSU is improved by its ability to detect early ischemic damage via automatic electronic (e) evaluation of CT scans using a novel software program that calculates the electronic Alberta Stroke Program Early CT Score (e-ASPECTS). METHODS: The feasibility of integrating e-ASPECTS into an ambulance was examined, and the clinical integration and utility of the software in 15 consecutive cases evaluated. RESULTS: Implementation of e-ASPECTS onto the MSU and into the prehospital stroke management was feasible. The values of e-ASPECTS matched with the results of conventional neuroradiologic analysis by the MSU team. The potential benefits of e-ASPECTS were illustrated by three cases. In case 1, excluding early infarct signs supported the decision to directly perform prehospital thrombolysis. In case 2, in which stroke was caused by large-vessel occlusion, the high e-ASPECTS value supported the decision to initiate intra-arterial treatment and triage the patient to a comprehensive stroke center. In case 3, the e-ASPECTS value was 10, indicating the absence of early infarct signs despite pre-existing cerebral microangiopathy and macroangiopathy, a finding indicating the program's robustness against artefacts. CONCLUSIONS: This study on the integration of e-ASPECTS into the prehospital stroke management via a MSU showed for the first time that such integration is feasible, and aids both decision regarding the treatment option and the triage regarding the most appropriate target hospital.

'Stroke Room': Diagnosis and Treatment at a Single Location for Rapid Intraarterial Stroke Treatment.

BACKGROUND: For patients with acute ischemic stroke, intra-arterial treatment (IAT) is considered to be an effective strategy for removing the obstructing clot. Because outcome crucially depends on time to treatment ('time-is-brain' concept), we assessed the effects of an intervention based on performing all the time-sensitive diagnostic and therapeutic procedures at a single location on the delay before intra-arterial stroke treatment. METHODS: Consecutive acute stroke patients with large vessel occlusion who obtained IAT were evaluated before and after implementation (April 26, 2010) of an intervention focused on performing all the diagnostic and therapeutic measures at a single site ('stroke room'). RESULT: After implementation of the intervention, the median intervals between admission and first angiography series were significantly shorter for 174 intervention patients (102 min, interquartile range (IQR) 85-120 min) than for 81 control patients (117 min, IQR 89-150 min; p < 0.05), as were the intervals between admission and clot removal or end of angiography (152 min, IQR 123-185 min vs. 190 min, IQR 163-227 min; p < 0.001). However, no significant differences in clinical outcome were observed. CONCLUSION: This study shows for the, to our knowledge, first time that for patients with acute ischemic stroke, stroke diagnosis and treatment at a single location ('stroke room') saves crucial time until IAT.

Dynamic (18)F-fluorodeoxyglucose positron emission tomography/CT in hibernoma: Enhanced tracer uptake mimicking liposarcoma.

We report on two cases of patients with fat-equivalent masses in computed tomography (CT), referred to our department for dynamic positron emission tomography/CT (dPET/CT) with (18)F-fluorodeoxyglucose ((18)F-FDG) in order to investigate their dignity. Both qualitative and quantitative information, as derived from dPET/CTs, couldn't exclude a high-grade liposarcoma: Visual evaluation, revealed a large hypermetabolic focus of intense (18)F-FDG uptake in each patient (average SUVs 8.3 and 11.3). Regression-based parametric imaging demonstrated an enhanced distribution volume, which correlates to perfusion, and a high phosphorylation rate that correlates to cell viability. Kinetic analysis, based on a two-tissue compartment model demonstrated an enhanced FDG transport k1 and an enhanced phosphorylation rate k3. A non-compartmental approach based on fractal dimension revealed also enhanced values. However, final diagnosis was based on biopsy, which revealed hibernoma, a benign brown fat tumor. Brown adipose contains increased numbers of mitochondria and a high-rate of glucose metabolism. Therefore, they have increased FDG uptake. The evaluation of lipomatous lesions on CT, with high FDG uptake, should include the possibility of hibernoma as a differential diagnosis.

Dynamic PET with FDG in patients with unresectable aggressive fibromatosis: regression-based parametric images and correlation to the FDG kinetics based on a 2-tissue compartment model.

OBJECTIVE: Dynamic PET (dPET) studies with 18F-FDG were performed in patients with unresectable aggressive fibromatosis before imatinib therapy. The goal of the study was to evaluate the impact of regression-based parametric imaging on tumor diagnostics. A comparison between the regression-based quantitative data (slope and intercept values) with the compartmental data of FDG was performed. METHODS: The evaluation includes 24 patients with recurrent disease (n = 14), residual tissue (n = 2), or primary disease (n = 8), who were scheduled for palliative treatment with imatinib. Parametric images were calculated based on the dPET data by fitting a linear regression function to the time-activity data and for each voxel. Images of the slope and the intercept of the time-activity data were calculated using a dedicated software. A volume-of-interest-based analysis was also performed by applying a 2-tissue compartment model to the dPET data. The resulting parameters of the FDG kinetics [blood volume (VB), k1-k4] were compared with the volume-of-interest-based slope and intercept data. The evaluation of the parametric images was performed visually and quantitatively. RESULTS: Twenty of 24 tumors could be visualized in the SUV images with a moderate uptake, in locations that were already known from the MR images. Most (16/24) of the tumors demonstrated a clear enhancement in the intercept images, whereas 4 of them showed an intermediate enhancement and only 4 did not show any enhancement in the intercept images. In contrast, only 10 of 24 tumors demonstrated a clearly enhanced slope, 3 of them revealed a slightly enhanced slope, and 11 of the 24 patients did not demonstrate any slope enhancement within the area of the known desmoid tumors. The comparison of slope revealed the highest correlation to the SUV (r = 0.56, P < 0.05), whereas the intercept values demonstrated the highest correlation to k1 (r = 0.794, P < 0.05), followed by the fractional VB (r = 0.709, P < 0.05), followed by SUV (r = 0.630, P < 0.05). The results indicate that slope images are related to the transport/phosphorylation-dependent part of FDG, whereas intercept images are related to the transport/perfusion part of FDG. CONCLUSIONS: These data demonstrate that the use of regression-based parametric imaging helps to differentiate between transport/perfusion- and transport/phosphorylation-dependent FDG uptake and demonstrate that the transport/phosphorylation rate is low in most of these tumors.

Incidental detection and monitoring of spontaneous recovery of sarcoidosis via fluorine-18-fluoroethyl-choline positron emission tomography/computed tomography.

We report a case of sarcoidosis detected incidentally by using fluorine-18-fluoroethylcholine- positron emission tomography/computed tomography (¹8F-FECH-PET/CT) in a 72 years old patient with prostate cancer, who had been referred for restaging after relapse indicated prostate specific antigen (PSA). The ¹8F-FECH-PET/CT examination showed a focal increased uptake in the prostate bed suggestive for local recurrence, in addition to multifocal uptake in the mediastinum matching with enlarged hilar and paratracheal lymph nodes. Histopathology revealed sarcoidosis. No treatment was recommended. Two years later the patient was referred again to us because of another recurrent PSA elevation. The second ¹8F-FECH-PET/CT showed again the previously described local recurrence, but did not show the previously described mediastinal findings nor the enlarged hilar and paratracheal lymph nodes, thus, illustrating spontaneous healing of sarcoidosis. In conclusion, this case suggests that ¹8F-FECH PET/CT study can show positive findings in sarcoidosis that were no longer detectable after two years, suggestive of spontaneous recovery.

Parametric images via dynamic 18F-fluorodeoxyglucose positron emission tomographic data acquisition in predicting midterm outcome of liver metastases secondary to gastrointestinal stromal tumours.

PURPOSE: (18)F-Fluorodeoxyglucose positron emission tomography (FDG PET) may underestimate viable tumour tissue in patients with gastrointestinal stromal tumours (GIST) treated with molecular targeted agents. The aim of the present study was to investigate the value of parametric images generated after dynamic data acquisition for the detection of active liver metastases. METHODS: The analysis included 65 dynamic FDG PET studies in 34 patients with liver metastases from GIST who were treated with imatinib or sunitinib. Parametric images of intercept and slope were calculated by dedicated software using a voxel-based linear regression of time-activity data. Intercept images represent the tracer's distribution volume and the slope its overall metabolic turnover. All images were assessed visually and semi-quantitatively. Liver disease status was established 12 months after each PET study. Dichotomous variables of visual interpretation and various quantitative parameters were entered in a statistical model of linear discriminant analysis. RESULTS: Visual analysis of slope images was more sensitive than the standard 1-h FDG uptake evaluation (70.6 vs 51.0%, p = 0.016) in detecting cases with liver disease progression (n = 51). Specificity did not differ. Combination of all variables in the discriminant analysis model correctly classified 87.7% of cases as progressive or non-progressive disease. Sensitivity was raised to 88.2%. CONCLUSION: Parametric images of intercept and slope add a new dimension to the interpretation of FDG PET studies, by isolating visually and quantifying the perfusion and phosphorylation-dependent part of tracer uptake. In treated GIST patients, integration of this information with the 1-h uptake data achieves better characterization of hepatic lesions with respect to disease activity.