Evaluation of time-resolved whole brain flat panel detector perfusion imaging using RAPID ANGIO in patients with acute stroke: comparison with CT perfusion imaging.

BACKGROUND In contrast to conventional CT perfusion (CTP) imaging, flat panel detector CT perfusion (FD-CTP) imaging can be acquired directly in the angiosuite. OBJECTIVE To evaluate time-resolved whole brain FD-CTP imaging and assess clinically important qualitative and quantitative perfusion parameters in correlation with previously acquired conventional CTP using the new RAPID for ANGIO software. METHODS We included patients with internal carotid artery occlusions and M1 or M2 occlusions from six centers. All patients underwent mechanical thrombectomy (MT) with preinterventional conventional CTP and FD-CTP imaging. Quantitative performance was determined by comparing volumes of infarct core, penumbral tissue, and mismatch. Eligibility for MT according to the perfusion imaging criteria of DEFUSE 3 was determined for each case from both conventional CTP and FD-CTP imaging. RESULTS A total of 20 patients were included in the final analysis. Conventional relative cerebral blood flow (rCBF) 6 s versus FD-CTP Tmax >6 s and CTP mismatch versus FD-CTP mismatch showed more variability (R2=0.57, and R2=0.33, respectively). Based on FD-CTP, 16/20 (80%) patients met the inclusion criteria for MT according to the DEFUSE 3 perfusion criteria, in contrast to 18/20 (90%) patients based on conventional CTP. The vessel occlusion could be correctly extrapolated from the hypoperfusion in 18/20 cases (90%). CONCLUSIONS In our multicenter study, time-resolved whole brain FD-CTP was technically feasible, and qualitative and quantitative perfusion results correlated with those obtained with conventional CTP

A neurovascular high-frequency optical coherence tomography system enables in situ cerebrovascular volumetric microscopy

Intravascular imaging has emerged as a valuable tool for the treatment of coronary and peripheral artery disease; however, no solution is available for safe and reliable use in the tortuous vascular anatomy of the brain. Endovascular treatment of stroke is delivered under image guidance with insufficient resolution to adequately assess underlying arterial pathology and therapeutic devices. High-resolution imaging, enabling surgeons to visualize cerebral arteries\u27 microstructure and micron-level features of neurovascular devices, would have a profound impact in the research, diagnosis, and treatment of cerebrovascular diseases. Here, we present a neurovascular high-frequency optical coherence tomography (HF-OCT) system, including an imaging console and an endoscopic probe designed to rapidly acquire volumetric microscopy data at a resolution approaching 10 microns in tortuous cerebrovascular anatomies. Using a combination of in vitro, ex vivo, and in vivo models, the feasibility of HF-OCT for cerebrovascular imaging was demonstrated

Glucose modifies the effect of endovascular thrombectomy in patients with acute stroke: a pooled-data meta-analysis

Background and Purpose: Hyperglycemia is a negative prognostic factor following acute ischemic stroke but is not known whether glucose is associated with the effects of endovascular thrombectomy in patients with large vessel stroke. In a pooled-data meta-analysis, we analyzed whether serum glucose is a treatment modifier of the efficacy of endovascular thrombectomy in acute stroke. Methods: Seven randomized trials compared endovascular thrombectomy with standard care between 2010 and 2017 (HERMES Collaboration). 1764 patients with large vessel stroke were allocated to endovascular thrombectomy (n=871) or standard care (n=893). Measurements included blood glucose on admission and functional outcome [modified Rankin Scale (mRS) range: 0-6; lower scores indicating less disability] at 3 months. The primary analysis evaluated whether glucose modified the effect of EVT over standard care on functional outcome, using ordinal logistic regression to test the interaction between treatment and glucose level. Results: Median (IQR) serum glucose on admission was 120 (104-140) mg/dl [6.6mmol/l (5.7-7.7) mmol/l]. Endovascular thrombectomy (EVT) was better than standard care in the overall pooled-data analysis [common odds ratio (acOR), 2.00 (95% CI 1.69–2.38); however, lower glucose levels were associated with greater effects of EVT over standard care. The interaction was nonlinear such that significant interactions were found in subgroups of patients split at glucose < or > 90mg/dl (5.0mmol/l) [(p=0.019 for interaction, acOR 3.81 (95% CI 1.73–8.41) for patients < 90 mg/dl vs 1.83 (95% CI 1.53–2.19) for patients > 90 mg/dl], and glucose < or > 100mg/dl (5.5mmol/l) [(p=0.004 for interaction, acOR 3.17 (95% CI 2.04–4.93) vs acOR 1.72 (95% CI 1.42–2.08)], but not between subgroups above these levels of glucose. Conclusions: Endovascular thrombectomy improved stroke outcomes compared to standard treatment regardless of glucose levels but the treatment effects were larger at lower glucose levels, with significant interaction effects persisting up to 90 to 100mg/dl (5.0-5.5mmol/l). Whether tight control of glucose improves the efficacy of endovascular thrombectomy following large vessel stroke warrants appropriate testing

Imaging features and safety and efficacy of endovascular stroke treatment: a meta-analysis of individual patient-level data

Background: Evidence regarding whether imaging can be used effectively to select patients for endovascular thrombectomy (EVT) is scarce. We aimed to investigate the association between baseline imaging features and safety and efficacy of EVT in acute ischaemic stroke caused by anterior large-vessel occlusion. Methods: In this meta-analysis of individual patient-level data, the HERMES collaboration identified in PubMed seven randomised trials in endovascular stroke that compared EVT with standard medical therapy, published between Jan 1, 2010, and Oct 31, 2017. Only trials that required vessel imaging to identify patients with proximal anterior circulation ischaemic stroke and that used predominantly stent retrievers or second-generation neurothrombectomy devices in the EVT group were included. Risk of bias was assessed with the Cochrane handbook methodology. Central investigators, masked to clinical information other than stroke side, categorised baseline imaging features of ischaemic change with the Alberta Stroke Program Early CT Score (ASPECTS) or according to involvement of more than 33% of middle cerebral artery territory, and by thrombus volume, hyperdensity, and collateral status. The primary endpoint was neurological functional disability scored on the modified Rankin Scale (mRS) score at 90 days after randomisation. Safety outcomes included symptomatic intracranial haemorrhage, parenchymal haematoma type 2 within 5 days of randomisation, and mortality within 90 days. For the primary analysis, we used mixed-methods ordinal logistic regression adjusted for age, sex, National Institutes of Health Stroke Scale score at admission, intravenous alteplase, and time from onset to randomisation, and we used interaction terms to test whether imaging categorisation at baseline modifies the association between treatment and outcome. This meta-analysis was prospectively designed by the HERMES executive committee but has not been registered. Findings: Among 1764 pooled patients, 871 were allocated to the EVT group and 893 to the control group. Risk of bias was low except in the THRACE study, which used unblinded assessment of outcomes 90 days after randomisation and MRI predominantly as the primary baseline imaging tool. The overall treatment effect favoured EVT (adjusted common odds ratio [cOR] for a shift towards better outcome on the mRS 2·00, 95% CI 1·69–2·38; p<0·0001). EVT achieved better outcomes at 90 days than standard medical therapy alone across a broad range of baseline imaging categories. Mortality at 90 days (14·7% vs 17·3%, p=0·15), symptomatic intracranial haemorrhage (3·8% vs 3·5%, p=0·90), and parenchymal haematoma type 2 (5·6% vs 4·8%, p=0·52) did not differ between the EVT and control groups. No treatment effect modification by baseline imaging features was noted for mortality at 90 days and parenchymal haematoma type 2. Among patients with ASPECTS 0–4, symptomatic intracranial haemorrhage was seen in ten (19%) of 52 patients in the EVT group versus three (5%) of 66 patients in the control group (adjusted cOR 3·94, 95% CI 0·94–16·49; pinteraction=0·025), and among patients with more than 33% involvement of middle cerebral artery territory, symptomatic intracranial haemorrhage was observed in 15 (14%) of 108 patients in the EVT group versus four (4%) of 113 patients in the control group (4·17, 1·30–13·44, pinteraction=0·012). Interpretation: EVT achieves better outcomes at 90 days than standard medical therapy across a broad range of baseline imaging categories, including infarcts affecting more than 33% of middle cerebral artery territory or ASPECTS less than 6, although in these patients the risk of symptomatic intracranial haemorrhage was higher in the EVT group than the control group. This analysis provides preliminary evidence for potential use of EVT in patients with large infarcts at baseline. Funding: Medtronic

The eJournal of the European Society of Minimally Invasive Neurological Therapy Overlapping stents in "Y" configuration for anterior circulation aneurysms Overlapping stents in "Y" configuration for anterior circulation aneurysms

Abstract Introduction: Stenting with a Y-configuration is an endovascular option for repairing wide-neck aneurysm

Neuro-endovascular Embolic Agent for Treatment of a Renal Arteriovenous Fistula

Renal arteriovenous fistula is a known complication following a renal biopsy, and may require catheter based embolization. Distal location of these fistulas in the renal parenchyma in many a case may necessitate non-traditional embolic materials. Liquid embolic agents that allow a controlled delivery may be suitable in this situation, as demonstrated in this case report

Transvenous arteriovenous malformation embolization

Transvenous embolization of arteriovenous malformations has emerged as a safe and effective intervention. In carefully selected patients the transvenous approach has shown efficacy similar to that of conventional transarterial routes. The optimal lesions amenable to the transvenous approach have not been robustly delineated; however, the approach is reserved for small, deep seeded, single venous drainage lesions with poorly amenable arterial vascular supply. In this video we demonstrate a case of transvernous Onyx embolization of a Spetzler-Martin grade 3 (SM3) left hemispheric, ruptured arteriovenous malformation. The patient underwent successful, single session, complete embolization of the arteriovenous malformation through a venous route without further complications or repeat treatment

Optical coherence tomography for elucidation of flow-diversion phenomena: The concept of endothelized mural thrombus behind reversible in-stent stenosis in flow-diverters

PURPOSE: Flow-diverters have revolutionized the endovascular treatment of intracranial aneurysms, offering a durable solution to aneurysms with high recurrence rates after conventional stent-assisted coiling. Events that occur after treatment with flow-diversion, such as in-stent stenosis (ISS) are not well understood and require further assessment. After assessing an animal model with Optical Coherence Tomography (OCT), we propose a concept that could explain the mechanism causing reversible ISS after treatment of intracranial aneurysms with flow-diverters. METHODS: Six Pipeline Flex embolization devices (PED-Flex), six PED with Shield technology (PED-Shield), and four Solitaire AB devices were implanted in the carotid arteries (two stents per vessel) of four pigs. Intravascular optical coherence tomography (OCT) and digital subtraction angiography (DSA) images obtained on day 21 were compared to histological specimens. RESULTS: A case of ISS in a PED-Flex device was assessed with OCT imaging. Neointima with asymmetrical topography completely covering the PED struts was observed. Histological preparations of the stenotic area demonstrated thrombus on the surface of device struts, covered by neointima. CONCLUSION: This study provides a plausible concept for reversible ISS in flow-diverters. Based on an observation of a previous experiment, we propose that similar cases of ISS are related to thrombus presence underneath endothelization, but further experiments focused on this phenomenon are needed. Optical Coherence Tomography will be useful tool when available for clinical use

Moyamoya Syndrome in an Adult with Essential Thrombocythemia

Moyamoya syndrome is a rare cerebrovascular disorder characterized by progressive occlusion of the supraclinoid internal carotid artery and proximal portions of the anterior and middle cerebral arteries resulting in an extensive network of collateralized blood vessels and producing a characteristic angiographic appearance. Although the pathophysiology is unclear, hematologic disorders have been associated with development of the moyamoya syndrome. A case report is presented. A 29 year-old female with a history of essential thrombocythemia developed progressive ischemic strokes. Angiography revealed characteristic moyamoya changes and pathologic examination showed intimal hyperplasia with scant collagen fibers and myxoid change. This is the first reported case of moyamoya syndrome in an adult patient with essential thrombocythemia demonstrating histological findings that suggest a shared pathophysiology with moyamoya syndrome in sickle cell anemia

Transvenous onyx embolization of carotid-cavernous fistulas: mid- and long-term outcomes

Objective Endovascular treatment of carotid-cavernous fistulas (CCFs) has been consistently shown to give excellent results and is currently the mainstay of treatment of these complex vascular pathologies. Onyx is currently the most widely used agent, but there has been concern over high rates of cranial nerve (CN) deficits seen in patients with CCF treated with Onyx and paucity of data on long-term outcomes. Methods This is a retrospective analysis of patients who underwent transvenous Onyx embolization between 2011 and 2018. The data collected included demographics, comorbidities, presenting symptoms, CCF morphology, degree of obliteration, procedure-related complications, clinical outcomes, and follow-up. Results A total of seven patients (five females) were included. The median age was 66 years (range: 15-79 years). Median duration of symptoms before treatment was 4 weeks (range: 1-24 weeks). There were three direct and four indirect CCFs. Barrow classification is as follows: A-3; B-3; C-0; and D-1. Immediate complete occlusion was achieved in all cases. There was also one case of immediate postoperative change in CN function (new partial CN VI deficit) that resolved completely at 1-month follow-up. The mean length of stay was 3 days (±2). The preoperative extraocular movement CN deficits had the following outcomes: three resolved; two improved; and one persisted. Proptosis, chemosis, conjunctival injection, and tinnitus were resolved in all patients. The median follow-up was 34 months (range: 10-91 months). Conclusion Transvenous Onyx embolization is a safe and effective treatment of CCFs when technical aspects to reduce complications are performed diligently. Our technique demonstrates safety of the Onyx as a stand-alone embolization for the treatment of CC