Romain Bourcier

Mechanical thrombectomy with the ERIC retrieval device: initial experience

Objective To report our experience with the Embolus Retriever with Interlinked Cage (ERIC) stentriever for use in mechanical endovascular thrombectomy (MET). Methods Thirty-four consecutive patients with acute stroke (21 men and 13 women; median age 66 years) determined appropriate for MET were treated with ERIC and prospectively included over a 6-month period at three different centers. The ERIC device differs from typical stentrievers in that it is designed with a series of interlinked adjustable nitinol cages that allow for fast thrombus capture, integration, and withdrawal. The evaluated endpoints were successful revascularization (Thrombolysis in Cerebral Infarction (TICI) 2b–3) and good clinical outcomes at 3 months (modified Rankin Scale (mRS) 0–2). Results Locations of the occlusions included the middle cerebral artery (13 patients), terminal carotid artery (11 patients), basilar artery (1 patient), and tandem occlusions (9 patients). IV thrombolysis was performed in 20/34 (58.8%) patients. Median times from symptom onset to recanalization and from puncture to recanalization were 325.5 min (180–557) and 78.5 min (14–183), respectively. Used as the first-line device, ERIC achieved a successful recanalization in 20/24 (83.3%) patients. Successful recanalization was associated with lower National Institutes of Health Stroke Scale scores at 24 h (8±6.5 vs 21.5±2.1; p=0.008) and lower mRS at 3 months (2.7±2.1 vs 5.3±1.1; p=0.04). Three procedural complications and four asymptomatic hemorrhages were recorded. Good clinical outcomes at 3 months were seen in 15/31 (48.4%) patients. Conclusions The ERIC device is an innovative stentriever allowing fast, effective, and safe MET.

Cytomegalovirus encephalitis: Undescribed diffusion-weighted imaging characteristics. Original aspects of cases extracted from a retrospective study, and from literature review

INTRODUCTION There is paucity of studies analyzing DWI in MRI sequences when imaging cytomegalovirus (CMV) meningoencephalitis. The main objective of this study is to demonstrate that DWI sequence is mandatory when imaging immunocompromised patients presenting with encephalitic symptoms, as this sequence can reveal very peculiar lesions in the setting of CMV encephalitis. PATIENTS AND METHOD Three CSF PCR CMV positive cases were identified in a 13-year retrospective study with MRI scans including T1, FLAIR, DWI with automated ADC calculation, and T1 with contrast injection, and were reviewed by a senior neuroradiologist. RESULTS Our three cases presented multiple high-signal intensity punctiform lesions in DWI, which uniformly were in restricted diffusion. Each patient had multiple lesions (mean 19.3, range 12-30): 96.5% were supratentorial and 3.5% were infratentorial. Among supratentorial lesions, 62.5% were subependymal, 28.6% were periventricular and 8.9% were subcortical. Some lesions remained in a long lasting restricted diffusion state. All cases had FLAIR curvilinear periventricular high signal intensities. No contrast uptake was found. DISCUSSION Punctiform DWI lesions had a clear ventricle wall tropism, consistent with classical autopsy findings. The classical histological knowledge-compatible explanation for long lasting diffusion restriction is non-lethal cytotoxic edema owing to CMV inclusions. CONCLUSION Subependymal and periventricular punctiform restricted diffusion lesions in the setting of meningoencephalitis in immunocompromised patients seem highly evocative of CMV encephalitis. The diffusion sequence probably reveals focal lesions constitutive of cellular viral inclusions.

Is bridging therapy still required in stroke due to carotid artery terminus occlusions

Introduction Studies comparing endovascular stroke treatment using mechanical thrombectomy (MT) with or without prior IV tissue plasminogen activator (tPa) have included only 30% of internal carotid artery terminus occlusions (ICA-O), a known predictor of recanalization failure with IV tPa. Objective To carry out a retrospective multicenter analysis of prospectively collected data of consecutive patients to investigate the impact of intravenous thrombolysis on ICA-O by comparing patients treated with MT alone or bridging therapy (BT). Material and methods Patients with ICA-O treated with MT alone or BT were retrospectively examined and compared. Demographic data, vascular risk factors, treatment modalities, complications, technical and clinical outcomes were recorded. A propensity score (PS) analysis was used to compare modified Rankin Scale (mRS) score at 3 months and intracerebral hemorrhage (ICH) between groups. Results 141 consecutive patients (60% BT/40% MT) were included between January 2014 and June 2016. Baseline characteristics did not differ between the groups. There was no significant difference in the rate of Thrombolysis in Cerebral Infarction 2b/3, distal emboli, and median number of passes between the groups. There was a significant difference between BT and MT groups in the median time between imaging and groin puncture (median 97 min vs 75, p=0.007), the rate of ICH (44% vs 27%, p=0.05), but not for symptomatic ICH (18% vs 13%, p=0.49). With PS, there was a trend towards a higher rate of ICH (OR=2.3, 95% CI 0.9 to 5.9, p=0.09) in the BT group compared with the MT alone group, with no difference in mRS score ≤2 at 3 months (OR=1.6, 95% CI 0.7 to 3.7, p=0.29). Conclusion There was no significant difference in clinical outcomes between patients receiving bridging therapy versus direct thrombectomy. Bridging therapy delayed time to groin puncture and increased ICH rate.

Is there an inherited anatomical conformation favoring aneurysmal formation of the anterior communicating artery

OBJECTIVE The pathophysiological mechanisms responsible for the formation of intracranial aneurysms (IAs) remain only partially elucidated. However, current evidence suggests a genetic component. The purpose of this study was to investigate the specific anatomical variations in the arterial complex that are associated with the presence of anterior communicating artery (ACoA) aneurysms in the familial forms of IAs. METHODS This multicenter study investigated bifurcation IAs in patients who had a sporadic ACoA IA without a family history of IA (SACAA group), in patients who had an ACoA IA with a family history of IA (FACAA group), and in their healthy first-degree relatives (HFDRs). Through the use of MR angiography (MRA) reconstructions, the symmetry of the A1 segments and the angle between the A1 and A2 segments were analyzed on 3D models for each group. These measurements were then compared among the 3 groups. RESULTS Twenty-four patients with SACAA, 24 patients with FACAA, and 20 HFDRs were included in the study. Asymmetrical configuration of the A1 segments was more frequent in the FACAA group than in the HFDR group (p = 0.002). The aneurysm-side A1-A2 angle was lower in the FACAA group (p = 0.003) and SACAA group (p = 0.007) than in the HFDR group. On the contralateral side, there was no difference in A1-A2 angles between groups. CONCLUSIONS The anatomical shape of the ACoA complex seems to be similarly associated with the presence of ACoA IAs in both the FACAA and SACAA groups. This highlights the role played by hemodynamic constraints in aneurysm formation and questions the hypothesis of the hereditary character of these anatomical shapes.

MRI Interscanner Agreement of the Association between the Susceptibility Vessel Sign and Histologic Composition of Thrombi: Inter-MRI Agreement of the Susceptibility Vessel Sign

The susceptibility vessel sign (SVS) on magnetic resonance imaging (MRI) is related to thrombus location, composition, and size in acute stroke. No previous study has determined its inter‐MRI scanner variability. We aimed to compare the diagnostic accuracy in‐vitro of four different MRI scanners for the characterization of histologic thrombus composition.

Outcome After Reperfusion Therapies in Patients With Large Baseline Diffusion-Weighted Imaging Stroke Lesions: A THRACE Trial (Mechanical Thrombectomy After Intravenous Alteplase Versus Alteplase Alone After Stroke) Subgroup Analysis

Background and Purpose— Stroke patients with large diffusion-weighted imaging (DWI) volumes are often excluded from reperfusion because of reckoned futility. In those with DWIvolume >70 mL, included in the THRACE trial (Mechanical Thrombectomy After Intravenous Alteplase Versus Alteplase Alone After Stroke), we report the associations between baseline parameters and outcome. Methods— We examined 304 patients with anterior circulation stroke and pretreatment magnetic resonance imaging. Variables were extracted from the THRACE database, and DWI volumes were measured semiautomatically. Results— Among 53 patients with DWIvolume >70 mL, 12 had favorable outcome (modified Rankin Scale score, ⩽2) at 3 months; they had less coronary disease (0/12 versus 12/38; P=0.046) and less history of smoking (1/10 versus 12/31; P=0.013) than patients with modified Rankin Scale score >2. None of the 8 patients >75 years of age reached modified Rankin Scale score ⩽2. Favorable outcome occurred in 12 of 37 M1-occluded patients but in 0 of 16 internal carotid-T/L–occluded patients (P=0.010). Favorable outcome was more frequent (6/13) when DWI lesion was limited to the superficial middle cerebral artery territory than when it extended to the deep middle cerebral artery territory (6/40; P=0.050). Conclusions— Stroke patients with DWI lesion >70 mL may benefit from reperfusion therapy, especially those with isolated M1 occlusion or ischemia restricted to the superficial middle cerebral artery territory. The benefit of treatment seems questionable for patients with carotid occlusion or lesion extending to the deep middle cerebral artery territory.

Susceptibility Vessel Sign in the ASTER Trial: Higher Recanalization Rate and More Favourable Clinical Outcome after First Line Stent Retriever Compared to Contact Aspiration

Romain Bourcier, Mickael Mazighi, Julien Labreuche, Robert Fahed, Raphael Blanc, Benjamin Gory, Alain Duhamel, Gaultier Marnat, Suzana Saleme, Vincent Costalat, Serge Bracard, Hubert Desal, Arturo Consoli, Michel Piotin, Bertrand Lapergue, on behalf of the ASTER Trial Investigators Department of Diagnostic and Interventional Neuroradiology, Guillaume et René Laennec University Hospital, Nantes, France Department of Diagnostic and Interventional Neuroradiology, Rothschild Foundation, Paris, France Department of Biostatistics, University Lille, CHRU Lille, Lille, France Department of Diagnostic and Interventional Neuroradiology, University Hospital of Nancy, Nancy, France Department of Diagnostic and Interventional Neuroradiology, University Hospital of Bordeaux, Bordeaux, France Department of Diagnostic and Interventional Neuroradiology, University Hospital of Limoges, Limoges, France Department of Diagnostic and Interventional Neuroradiology, University Hospital of Montpellier, Montpellier, France Department of Stroke Center and Diagnostic and Interventional Neuroradiology, University of Versailles and Saint Quentin en Yvelines, Foch Hospital, Suresnes, France

Understanding the Pathophysiology of Intracranial Aneurysm: The ICAN Project

BACKGROUND Understanding the pathophysiologic mechanism of intracranial aneurysm (IA) formation is a prerequisite to assess the potential risk of rupture. Nowadays, there are neither reliable biomarkers nor diagnostic tools to predict the formation or the evolution of IA. Increasing evidence suggests a genetic component of IA but genetics studies have failed to identify genetic variation causally related to IA. OBJECTIVE To develop diagnostic and predictive tools for the risk of IA formation and rupture. METHODS The French ICAN project is a noninterventional nationwide and multicentric research program. Each typical IA of bifurcation will be included. For familial forms, further IA screening will be applied among first-degree relatives. By accurate phenotype description with high-throughput genetic screening, we aim to identify new genes involved in IA. These potential genetic markers will be tested in large groups of patients. Any relevant pathway identified will be further explored in a large cohort of sporadic carriers of IA, which will be well documented with clinical, biological, and imaging data. EXPECTED OUTCOMES Discovering genetic risk factors, better understanding the pathophysiology, and identifying molecular mechanisms responsible for IA formation will be essential bases for the development of biomarkers and identification of therapeutic targets. DISCUSSION Our protocol has many assets. A nationwide recruitment allows for the inclusion of large pedigrees with familial forms of IA. It will combine accurate phenotyping and comprehensive imaging with high-throughput genetic screening. Last, it will enable exploiting metadata to explore new pathophysiological pathways of interest by crossing clinical, genetic, biological, and imaging information.

Voxel based analysis of recurrence dynamics in intracranial aneurysms after coiling

Background Understanding aneurysm growth is critical for the appropriate follow-up of patients after coil embolization and the need for retreatment. The purpose of the study was to stratify the growth dynamics of aneurysm recurrences after coiling by volumetric analysis and to determine predictive factors for aneurysm recurrences. Methods Source images of follow-up three-dimensional time of flight MR angiography (ToF-MRA) scans were compared with the first post-interventional ToF-MRA scan and analyzed for residual flow after co-registration using ANALYZE-software. In the event of incomplete occlusion, the residual volume was segmented and calculated. Growth dynamic was determined for each aneurysm after embolization. Results We analyzed 326 patients with 345 aneurysms from two centers. Each case had at least two ToF-MRA examinations after endovascular therapy. The mean observation interval was 59 months. Volumetric analysis of 1139 follow-up MRAs revealed that 218/345 aneurysms (63.2%) showed complete occlusion on initial follow-up imaging, and of these 95.0% remained stable. A steady increase in intra-aneurysmal flow was observed in 83/345 (24.1%). Less frequent observations were a steep increase (21/345; 6.1%) and a decrease (27/345; 7.8%). Independent predictors of increasing residual flow were greatest aneurysm diameter, total coil length, and incomplete occlusion. Conclusions Volumetric analysis of registered three-dimensional ToF-MRA follow-up datasets allows the detection of different growth patterns with high precision, avoids the low inter-rater reliability, and represents a promising approach for future studies that include analysis of more complex predictors of residual flow. In cases of aneurysm recurrence after coiling, the major pattern seems to be a steady increase in intra-aneurysmal flow over several months.

Sindrome di vasocostrizione cerebrale reversibile

La sindrome di vasocostrizione cerebrale reversibile associa delle cefalee improvvise inusuali, in genere a colpo di tuono, e una vasocostrizione segmentaria diffusa delle arterie intracraniche, che regredisce in tre mesi. Essa e attribuita a un malfunzionamento acuto e transitorio della regolazione del tono vascolare intracranico, di evoluzione, il piu delle volte, favorevole. Tuttavia, possono presentarsi delle complicanze, come degli infarti cerebrali, delle emorragie intracraniche o un edema cerebrale, o immediatamente o dopo una fase di cefalee isolate, rendendo necessarie una diagnosi e una gestione precoci. La sindrome di vasocostrizione cerebrale reversibile puo essere idiopatica o secondaria, il piu delle volte in un contesto di post-partum o di consumo di agenti tossici o di farmaci vasoattivi. Il suo trattamento consiste nell’eliminazione di un eventuale fattore scatenante, associata a misure sintomatiche ed empiricamente a un trattamento con calcioantagonista vasodilatatore.