Acute Anterior Circulation Large Vessel Research Articles

Automated CT Perfusion Imaging Versus Non-contrast CT for Ischemic Core Assessment in Large Vessel Occlusion

There is increasing use of automated computed tomography perfusion (CTP) to aid thrombectomy decision in emergent large vessel occlusion. It is important to understand the performance of these software packages in predicting ischemic core and tissue-at-risk in the real-world setting. The aim of this study was to evaluate whether ischemic core on non-contrast CT (NCCT) and automated CTP correspond and predict infarct extent after thrombectomy for ischemic stroke. Consecutive patients with acute anterior circulation large vessel occlusion undergoing successful thrombectomy (TICI2b/3) were studied. All patients had baseline CT, CTP with RAPID post-processing software (RAPID-CTP), and post-thrombectomy 24 h CT. Ischemic cores were assessed by two blinded raters independently using the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) on each modality. The interrater agreement for ASPECTS, and correlation between baseline CT-ASPECTS, RAPID-CTP-ASPECTS, and 24h CT-ASPECTS were calculated. A total of 86patients with amean age of 70.3 years (SD 16.5) were studied. The median baseline CT-ASPECTS was 9.5 (interquartile range, IQR8-10), median RAPID-CTP-ASPECTS was 9 (IQR8-10), and mean RAPID-CTP-ischemic core volume was 14.4ml (SD 27.9ml). The mean mismatch volume (difference of Tmax > 6s and cerebral blood flow (CBF) < 30%) was 128.6ml (SD 126.0ml). There was substantial correlation between baseline and 24h CT-ASPECTS (rs: 0.62; p < 0.001), but poor correlation between RAPID-CTP-ASPECTS and RAPID-CTP ischemic core volume with 24h NCCT-ASPECTS (rs: 0.21; p = 0.06 and -0.16; p = 0.15 respectively). The positive predictive value of any established infarct for baseline CT-ASPECTS was 81%, while that of RAPID-CTP-ASPECTS was 64%. In this series of successfully revascularized patients, ischemic core as estimated by RAPID-CTP-ASPECTS did not correlate with the baseline CT and tended to depict alarger infarct core than the infarct extent as assessed by 24h CT-ASPECTS.

Validation of iScore and PLAN Score for Death in Thrombectomy in Acute Stroke Due to Anterior Circulation Large Artery Occlusion

BackgroundTo validate iScore and PLAN score in acute anterior circulation large vessel occlusion stroke patients undergoing thrombectomy. MethodsiScore and PLAN score were calculated for consecutive acute ischemic stroke undergoing thrombectomy were included and death at 1 month and death at 3 months were recorded. The area under the receiver operating characteristic curve was used to assess the discrimination ability of the scales for death. ResultsTwo hundred and twenty-nine patients were included, 25.3% (58 of 229) of patient died at 1 month after thrombectomy and 25.8% (59 of 229) of them died at 3 months after thrombectomy. The receiver operator curve analysis found that iScore (area under the curve [AUC] = .76, 95% confidence interval [CI] .69-.83) was numerically better than PLAN score (AUC = .73, 95% CI .66-.81) for predicting death at day 90. The cut-off for iScore is 193, with sensitivity 64%, specificity 79%, positive predictive value 75% and negative predictive value 69%. ConclusionsThe iScore scale is a valid predictive tool for death in anterior circulation large vessel occlusions undergoing thrombectomy.

Deconstruction of Interhospital Transfer Workflow in Large Vessel Occlusion: Real-World Data in the Thrombectomy Era.

Interhospital transfer is a critical component in the treatment of acute anterior circulation large vessel occlusive stroke transferred for mechanical thrombectomy. Real-world data for benchmarking and theoretical modeling are limited. We sought to characterize transfer workflow from primary stroke center (PSC) to comprehensive stroke center after the publication of positive thrombectomy trials. Consecutive patients transferred from 3 high-volume PSCs to a single comprehensive stroke center between January 2015 and August 2016 were included in a retrospective study. Factors associated with key time metrics were analyzed with emphasis on PSC intrahospital workflow. Sixty-seven patients were identified. Median age was 74 years (interquartile range [IQR], 63.5-78) and National Institutes of Health Stroke Scale 17 (IQR, 12-21). Median transfer time measured by PSC-door-to-comprehensive stroke center-door was 128 minutes (IQR, 107-164), of which 82.8% was spent at PSCs (door-in-door-out [DIDO]; 106 minutes; IQR, 86-143). The lengthiest component of DIDO was computed-tomography-to-retrieval-request (median 59.5 minutes; IQR, 44-83). The 37.3% had DIDO exceeding 120 minutes. DIDO times differed significantly between PSCs (P=0.01). In multivariate analyses, rerecruiting the initial ambulance crew for transfer (P<0.01) and presentation during working hours (P=0.04) were associated with shorter DIDO times. In a metropolitan hub-and-spoke network, PSC-door-to-comprehensive stroke center-door and DIDO times are long even in high-volume PSCs. Improving PSC workflow represents a major opportunity to expedite mechanical thrombectomy and improve patient outcomes.

Value of CT angiography in anterior circulation large vessel occlusive stroke: Imaging findings, pearls, and pitfalls

Hyperacute stroke imaging is playing an increasingly important role in determining management decisions in acute stroke patients, particularly patients with large vessel occlusive stroke who may benefit from endovascular intervention. CT angiography (CTA) is an important tool in the work-up of the acute stroke patient. It reliably detects large occlusive thrombi in proximal cerebral arteries and is a quick and highly accurate method in identifying candidates for endovascular stroke treatment. In this article we review the imaging findings on CTA in acute large vessel occlusive stroke using a pictorial case based approach. We retrospectively reviewed CTA studies in 48 patients presenting with acute anterior circulation large vessel occlusive stroke who were brought for intra-arterial acute stroke intervention. We discuss and illustrate patterns of proximal intracranial arterial occlusion, collateralization to the occluded territory, as well as reviewing some important pearls, pitfalls and teaching points in CTA assessment of the acute stroke patient. Performed from the level of the aortic arch CTA also gives valuable information regarding the state of other vessels in the acute stroke patient, identifying additional significant vascular stenoses or occlusions, and as we illustrate, can demonstrate other clinically significant findings which may impact on patient management and outcome.