Brush sign and collateral supply as potential markers of large infarct growth after successful thrombectomy.

OBJECTIVES: To investigate the relationships between brush sign and cerebral collateral status on infarct growth after successful thrombectomy. METHODS: HIBISCUS-STROKE cohort includes acute ischemic stroke patients treated with thrombectomy after MRI triage and undergoing a day-6 MRI including FLAIR images to quantify final infarct volume (FIV). Successful reperfusion was defined as a modified thrombolysis in cerebral infarction score ≥ 2B. Infarct growth was calculated by subtracting FIV from baseline ischemic core after co-registration and considered large (LIG) when > 11.6 mL. Brush sign was assessed on T2*-weighted-imaging and collaterals were assessed using the hypoperfusion intensity ratio, which is the volume of Time-To-Tmax (Tmax) ≥ 10 s divided by the volume of Tmax ≥ 6 s. Good collaterals were defined by a hypoperfusion intensity ratio < 0.4. RESULTS: One hundred and twenty-nine patients were included, of whom 45 (34.9%) had a brush sign and 63 (48.8%) good collaterals. Brush sign was associated with greater infarct growth (p = 0.01) and larger FIV (p = 0.02). Good collaterals were associated with a smaller baseline ischemic core (p < 0.001), larger penumbra (p = 0.04), and smaller FIV (p < 0.001). Collateral status was not significantly associated with brush sign (p = 0.20) or with infarct growth (p = 0.67). Twenty-eight (22.5%) patients experienced LIG. Univariate regressions indicated that brush sign (odds ratio (OR) = 4.8; 95% confidence interval (CI): [1.9;13.3]; p = 0.004) and hemorrhagic transformation (OR = 1.7; 95%CI: [1.2;2.6]; p = 0.04) were predictive of LIG. In multivariate regression, only the brush sign remained predictive of LIG (OR = 5.2; 95%CI: [1.8-16.6], p = 0.006). CONCLUSIONS: Brush sign is a predictor of LIG after successful thrombectomy and cerebral collateral status is not. KEY POINTS: • Few predictors of ischemic growth are known in ischemic stroke patients achieving successful mechanical thrombectomy. • Our results suggest that the brush sign-a surrogate marker of severe hypoperfusion-is independently associated with large ischemic growth (> 11.6 mL) after successful thrombectomy whereas cerebral collateral status does not.

Is the optimal Tmax threshold identifying perfusion deficit volumes variable across MR perfusion software packages? A pilot study.

PURPOSE: Accurate quantification of ischemic core and ischemic penumbra is mandatory for late-presenting acute ischemic stroke. Substantial differences between MR perfusion software packages have been reported, suggesting that the optimal Time-to-Maximum (Tmax) threshold may be variable. We performed a pilot study to assess the optimal Tmax threshold of two MR perfusion software packages (A: RAPID®; B: OleaSphere®) by comparing perfusion deficit volumes to final infarct volumes as ground truth. METHODS: The HIBISCUS-STROKE cohort includes acute ischemic stroke patients treated by mechanical thrombectomy after MRI triage. Mechanical thrombectomy failure was defined as a modified thrombolysis in cerebral infarction score of 0. Admission MR perfusion were post-processed using two packages with increasing Tmax thresholds (≥ 6 s, ≥ 8 s and ≥ 10 s) and compared to final infarct volume evaluated with day-6 MRI. RESULTS: Eighteen patients were included. Lengthening the threshold from ≥ 6 s to ≥ 10 s led to significantly smaller perfusion deficit volumes for both packages. For package A, Tmax ≥ 6 s and ≥ 8 s moderately overestimated final infarct volume (median absolute difference: - 9.5 mL, interquartile range (IQR) [- 17.5; 0.9] and 0.2 mL, IQR [- 8.1; 4.8], respectively). Bland-Altman analysis indicated that they were closer to final infarct volume and had narrower ranges of agreement compared with Tmax ≥ 10 s. For package B, Tmax ≥ 10 s was closer to final infarct volume (median absolute difference: - 10.1 mL, IQR: [- 17.7; - 2.9]) versus - 21.8 mL (IQR: [- 36.7; - 9.5]) for Tmax ≥ 6 s. Bland-Altman plots confirmed these findings (mean absolute difference: 2.2 mL versus 31.5 mL, respectively). CONCLUSIONS: The optimal Tmax threshold for defining the ischemic penumbra appeared to be most accurate at ≥ 6 s for package A and ≥ 10 s for package B. This implies that the widely recommended Tmax threshold ≥ 6 s may not be optimal for all available MRP software package. Future validation studies are required to define the optimal Tmax threshold to use for each package.

Benefit of mechanical thrombectomy in acute ischemic stroke related to calcified cerebral embolus.

PURPOSE: Mechanical thrombectomies (MT) in patients with large vessel occlusion (LVO) related to calcified cerebral embolus (CCE) have been reported, through small case series, being associated with low reperfusion rate and worse outcome, compared to regular MT. The purpose of the MASC (Mechanical Thrombectomy in Acute Ischemic Stroke Related to Calcified Cerebral Embolus) study was to evaluate the incidence of CCEs treated by MT and the effectiveness of MT in this indication. METHODS: The MASC study is a retrospective multicentric (n = 37) national study gathering the cases of adult patients who underwent MT for acute ischemic stroke with LVO related to a CCE in France from January 2015 to November 2019. Reperfusion rate (mTICI ≥ 2B), complication rate and 90-day mRS were systematically collected. We then conducted a systematic review by searching for articles in PubMed, Cochrane Library, Embase and Google Scholar from January 2015 to March 2020. A meta-analysis was performed to estimate clinical outcome at 90 days, reperfusion rate and complications. RESULTS: We gathered data from 35 patients. Reperfusion was obtained in 57% of the cases. Good clinical outcome was observed in 28% of the patients. The meta-analysis retrieved 136 patients. Reperfusion and good clinical outcome were obtained in 50% and 29% of the cases, respectively. CONCLUSION: The MASC study found worse angiographic and clinical outcomes compared to regular thrombectomies. Individual patient-based meta-analysis including the MASC findings shows a 50% reperfusion rate and a 29% of good clinical outcome.

Surface-modified flow diverter p48-MW-HPC: Preliminary clinical experience in 28 patients treated in two centers.

BACKGROUND AND PURPOSE: Flow diversion is increasingly used for endovascular treatment of distal intracranial aneurysms and has led to the development of small diameter flow diverters such as p48-MW (phenox, Bochum, Germany). Use of flow diverters is limited, however, as patients require dual antiplatelet treatment to avoid thromboembolic complications. Hydrophilic Polymer Coating was developed to reduce platelet aggregation on the p48-MW (p48-MW-HPC). This study reports preliminary experience with p48-MW-HPC in aneurysm treatment in two centers. MATERIALS AND METHODS: Patients with ruptured, unruptured, and recanalized aneurysms treated with p48-MW-HPC were prospectively included and retrospectively analyzed for safety and efficacy. Safety was evaluated by analyzing intra- and postoperative complications as well as thromboembolic events depicted by DWI in the 72 h post-procedure. Efficacy was evaluated at 6 months based on aneurysm occlusion. RESULTS: From April 2019 to May 2020, 28 patients aged 25-82 years with 29 aneurysms were treated. Two thromboembolic events (7.1%) were reported with good clinical outcome. Final morbidity and mortality were both 0.0%. Post-operative DWI-MRI was depicting lesions in 70.0% of patients. Short-term (6 months) anatomical results were complete aneurysm occlusion in 87.0% of aneurysms, neck remnant in 8.7%, and aneurysm remnant in 4.3%. CONCLUSION: This preliminary clinical evaluation conducted in a relatively small sample size shows high feasibility (100.0%) of p48-MW-HPC aneurysm treatment, without morbidity or mortality, and high efficacy (complete occlusion in 90.0%). Additional larger comparative studies are needed to confirm these results and optimize perioperative antiplatelet treatment.

"Adaptative endovascular strategy to the CloT MRI in large intracranial vessel occlusion" (VECTOR): Study protocol of a randomized control trial.

A correlation between the susceptibility vessel sign (SVS) and red thrombi has been identified in MRI. We hypothesized that the Embotrap allow better retrieving of SVS+ thrombi. The AdaptatiVe Endovascular strategy to the CloT MRI in large intracranial vessel Occlusion (VECTOR) trial is a multicenter, prospective and randomized study designed to compare a first-line strategy combining Embotrap added to contact aspiration (CA) versus CA alone in patients with SVS+ occlusions.

Endovascular treatment of visceral artery aneurysms and pseudoaneurysms with stent-graft: Analysis of immediate and long-term results. / Tratamiento endovascular de aneurismas y pseudoaneurismas de arterias viscerales mediante stenstents recubiertos: análisis de resultados inmediatos y a largo plazo.

INTRODUCTION: The aim of this study is to analyze the safety and efficacy of stent-graft endovascular treatment for visceral artery aneurysms and pseudoaneurysms. METHODS: Multicentric retrospective series of patients with visceral aneurysms and pseudoaneurysms treated by means of stent graft. The following variables were analyzed: Age, sex, type of lesion (aneurysms/pseudoaneurysms), localization, rate of success, intraprocedural and long term complication rate (SIR classification). Follow-up was performed under clinical and radiological assessment. RESULTS: Twenty-five patients (16 men), with a mean age of 59 (range 27-79), were treated. The indication was aneurysm in 19 patients and pseudoaneurysms in 6. The localizations were: splenic artery (12), hepatic artery (5), renal artery (4), celiac trunk (3) and gastroduodenal artery (1). Successful treatment rate was 96% (24/25 patients). Intraprocedural complication rate was 12% (4% major; 8% minor). Complete occlusion was demonstrated during follow up (mean 33 months, range 6-72) in the 24 patients with technical success. Two stent migrations (2/24; 8%) and 4stent thrombosis (4/24; 16%) were detected. Mortality rate was 0%. CONCLUSION: In our study, stent-graft endovascular treatment of visceral aneurysmns and pseudoaneurysms has demonstrated to be safe and is effective in the long-term in both elective and emergent cases, with a high rate of successful treatment and a low complication rate.

Percutaneous Cryoablation under Conscious Sedation: A Safe, Effective and Painless Option for the Treatment of Pediatric Osteoid Osteoma.

BACKGROUND: Percutaneous CT-guided cryoablation is an emerging technique for treating bone tumors. However, experience with using this procedure for osteoid osteomas in pediatric patients remains limited. Our study aims to assess its technical feasibility, clinical efficacy, and safety in children treated under conscious anesthesia. METHODS: We conducted a retrospective study of consecutive pediatric patients who underwent CT-guided percutaneous cryoablation for osteoid osteomas at our institution between September 2017 and March 2021. All patients received conscious anesthesia. Data on peri-procedural VAS scores, post-procedural VAS scores, imaging findings, and nonsteroidal anti-inflammatory drug (NSAID) usage rates were collected for each patient. Technical success was defined as proper cryoprobe placement at the nidus center, while clinical success referred to pain relief without NSAID use. Intra- and post-operative complications were also evaluated. RESULTS: Nine patients underwent CT-guided percutaneous cryoablation for osteoid osteomas under conscious sedation, with a 100% overall success rate with low peri-procedural and median VAS scores (p < 0.01). No complications were observed during or after the procedure. CONCLUSIONS: CT-guided percutaneous cryoablation of pediatric osteoid osteomas is an effective and safe minimally invasive procedure feasible under conscious anesthesia, holding promise as a valuable treatment option.

Assessment of three MR perfusion software packages in predicting final infarct volume after mechanical thrombectomy.

AIMS: To evaluate the performance of three MR perfusion software packages (A: RAPID; B: OleaSphere; and C: Philips) in predicting final infarct volume (FIV). METHODS: This cohort study included patients treated with mechanical thrombectomy following an admission MRI and undergoing a follow-up MRI. Admission MRIs were post-processed by three packages to quantify ischemic core and perfusion deficit volume (PDV). Automatic package outputs (uncorrected volumes) were collected and corrected by an expert. Successful revascularization was defined as a modified Thrombolysis in Cerebral Infarction (mTICI) score ≥2B. Uncorrected and corrected volumes were compared between each package and with FIV according to mTICI score. RESULTS: Ninety-four patients were included, of whom 67 (71.28%) had a mTICI score ≥2B. In patients with successful revascularization, ischemic core volumes did not differ significantly from FIV regardless of the package used for uncorrected and corrected volumes (p>0.15). Conversely, assessment of PDV showed significant differences for uncorrected volumes. In patients with unsuccessful revascularization, the uncorrected PDV of packages A (median absolute difference -40.9 mL) and B (median absolute difference -67.0 mL) overestimated FIV to a lesser degree than package C (median absolute difference -118.7 mL; p=0.03 and p=0.12, respectively). After correction, PDV did not differ significantly from FIV for all three packages (p≥0.99). CONCLUSIONS: Automated MRI perfusion software packages estimate FIV with high variability in measurement despite using the same dataset. This highlights the need for routine expert evaluation and correction of automated package output data for appropriate patient management.

Blood-Brain Barrier Permeability and Kinetics of Inflammatory Markers in Acute Stroke Patients Treated With Thrombectomy.

BACKGROUND AND OBJECTIVES: The aim of this study was to investigate the relationship between baseline blood-brain barrier (BBB) permeability and the kinetics of circulating inflammatory markers in a cohort of acute ischemic stroke (AIS) patients treated with mechanical thrombectomy. METHODS: The CoHort of Patients to Identify Biological and Imaging markerS of CardiovascUlar Outcomes in Stroke includes AIS patients treated with mechanical thrombectomy after admission MRI and undergoing a sequential assessment of circulating inflammatory markers. Baseline dynamic susceptibility perfusion MRI was postprocessed with arrival time correction to provide K2 maps reflecting BBB permeability. After coregistration of apparent diffusion coefficient and K2 maps, the 90th percentile of K2 value was extracted within baseline ischemic core and expressed as a percentage change compared with contralateral normal-appearing white matter. Population was dichotomized according to the median K2 value. Univariable and multiple variable logistic regression analyses were performed to investigate factors associated with increased pretreatment BBB permeability in the whole population and in patients with symptom onset <6 hours. RESULTS: In the whole population (n = 105 patients, median K2 = 1.59), patients with an increased BBB permeability had higher serum levels of matrix metalloproteinase (MMP)-9 at H48 (p = 0.02), a higher C-reactive protein (CRP) serum level at H48 (p = 0.01), poorer collateral status (p = 0.01), and a larger baseline ischemic core (p < 0.001). They were more likely to have hemorrhagic transformation (p = 0.008), larger final lesion volume (p = 0.02), and worst neurologic outcome at 3 months (p = 0.04). The multiple variable logistic regression indicated that an increased BBB permeability was associated only with ischemic core volume (odds ratio [OR] 1.04, 95% CI 1.01-1.06, p < 0.0001). Restricting analysis to patients with symptom onset <6 hours (n = 72, median K2 = 1.27), participants with an increased BBB permeability had higher serum levels of MMP-9 at H0 (p = 0.005), H6 (p = 0.004), H24 (p = 0.02), and H48 (p = 0.01), higher CRP levels at H48 (p = 0.02), and a larger baseline ischemic core (p < 0.0001). The multiple variable logistic analysis showed that increased BBB permeability was independently associated with higher H0 MMP-9 levels (OR 1.33, 95% CI 1.12-1.65, p = 0.01) and a larger ischemic core (OR 1.27, 95% CI 1.08-1.59, p = 0.04). DISCUSSION: In AIS patients, increased BBB permeability is associated with a larger ischemic core. In the subgroup of patients with symptom onset <6 hours, increased BBB permeability is independently associated with higher H0 MMP-9 levels and a larger ischemic core.

Effect of the COVID-19 pandemic on acute stroke reperfusion therapy: data from the Lyon Stroke Center Network.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic would have particularly affected acute stroke care. However, its impact is clearly inherent to the local stroke network conditions. We aimed to assess the impact of COVID-19 pandemic on acute stroke care in the Lyon comprehensive stroke center during this period. METHODS: We conducted a prospective data collection of patients with acute ischemic stroke (AIS) treated with intravenous thrombolysis (IVT) and/or mechanical thrombectomy (MT) during the COVID-19 period (from 29/02/2020 to 10/05/2020) and a control period (from 29/02/2019 to 10/05/2019). The volume of reperfusion therapies and pre and intra-hospital delays were compared during both periods. RESULTS: A total of 208 patients were included. The volume of IVT significantly decreased during the COVID-period [55 (54.5%) vs 74 (69.2%); p = 0.03]. The volume of MT remains stable over the two periods [72 (71.3%) vs 65 (60.8%); p = 0.14], but the door-to-groin puncture time increased in patients transferred for MT (237 [187-339] vs 210 [163-260]; p < 0.01). The daily number of Emergency Medical Dispatch calls considerably increased (1502 [1133-2238] vs 1023 [960-1410]; p < 0.01). CONCLUSIONS: Our study showed a decrease in the volume of IVT, whereas the volume of MT remained stable although intra-hospital delays increased for transferred patients during the COVID-19 pandemic. These results contrast in part with the national surveys and suggest that the impact of the pandemic may depend on local stroke care networks.

Angiographic Patterns and Outcomes Achieved by Proximal Balloon Occlusion in Symptomatic Carotid Artery Stenosis Stenting.

BACKGROUND AND PURPOSE: The best embolic protection strategy has not yet been established for carotid artery stenting (CAS). This article reports a new simplified approach using a balloon guide catheter inspired by stroke therapy, in patients harboring a symptomatic ICA atherosclerotic stenosis or web. In addition, the three angiographic patterns and clinical outcomes associated with this technique, called the simple flow blockage (SFB) technique are described. MATERIAL AND METHODS: This was a retrospective study with data extraction from a monocentric prospective clinical registry of consecutive patients admitted for symptomatic ICA stenosis or web. The primary study outcome (composite endpoint) was the rate of occurrence of death, symptomatic stroke or acute coronary syndrome within 30 days of the intervention. RESULTS: In this study 75 symptomatic patients with >50% carotid artery atherosclerotic stenosis or web were included. All procedures were successfully performed. The composite endpoint occurred in 3 patients (4.0%, 95% confidence interval, CI, 0.0-11.3): 1 had symptomatic ischemic stroke, 1 had reperfusion syndrome with symptomatic intracranial hemorrhage and 1 had acute coronary syndrome. After proximal balloon inflation three angiographic patterns were observed: complete contrast column stagnation in the ICA (38.7%), retrograde washout of the ICA from the intracranial circulation towards the external carotid artery (35.5%) and antegrade washout of contrast medium towards the intracranial circulation (25.8%). The median procedure length was 40 min. New asymptomatic ischemic lesions were observed in 22.5% on DWI-MRI. CONCLUSION: The SFB technique enables fast and safe procedures in CAS. A favorable angiographic pattern after proximal balloon inflation was observed in 74.2% of cases.

Current status of Interventional Radiology in the management of Gastro-Entero-Pancreatic Neuroendocrine Tumours (GEP-NETs).

Within the group of Gastro-Entero-Pancreatic Neuroendocrine tumours (GEP-NETs), several heterogeneous malignancies are included with a variety of clinical manifestations and imaging characteristics. Often these cases are inoperable and minimal invasive treatment offered by image-guided procedures appears to be the only option. Interventional radiology offers a valid solution in the management of primary and metastatic GEP-NETs. The purpose of this review article is to describe the current status of the role of Interventional Radiology in the management of GEP-NETs.