This review looks back on our experience with acute middle cerebral artery embolectomies in the 1990s, frowned upon by stroke experts at the time, and no match for the newly introduced and proven treatment of acute ischemic stroke with intravenous recombinant tissue plasminogen activator (alteplase). The past several decades have seen dramatic developments in acute cerebral revascularization, the major paradigm shift being in the form of endovascular thrombectomy. Mechanical thrombectomy has moved from the operating room, where we performed it, to the interventional angiography suite armed with ever-improving clot aspiration and retrieval technologies.

The variable rate of infarct progression in acute ischemic stroke as assessed by various thresholds excludes a substantial proportion of patients due to time or core constraints. We evaluated 106 patients with any-type occlusion to compare these thresholds and assessed performance of hypoperfusion index (HI) for fast and slow rate of infarct progression. Seven (12.5%) were classified fast progressors and 23 (46%), 25 (50%), 12 (24%), and 33 (66%) slow progressors using different core and time criteria. In comparison, HI categorized 100% (n = 106) of cohort with optimal cutoff 0.5 for any-type occlusion (slow progressors: HI ≤ 0.5), sensitivity/specificity 100%/91%, AUC 0.94, and indicative of eligibility for reperfusion and clinical outcomes (median 90-day modified Rankin Scale; 2 for HI ≤ 0.5 versus 5). Estimation of progressors by HI seems comprehensive but needs external validation.

Endovascular thrombectomy (EVT) has revolutionized the care of patients with acute ischemic stroke. The efficacy of EVT is dependent on the optimal setup of a stroke system. Extrapolating the results of clinical trials to any individual stroke center should be done with caution. This is more important for centers with suboptimal stroke systems of care. The Canadian registry has helped highlight the suboptimal outcome post EVT in Manitoba. This could potentially be optimized with the addition of an acute stroke unit in the near future. Our study will serve as a baseline for future improvement in acute stroke care.

Silent pulmonary embolism (PE) may be associated with acute ischemic stroke (AIS). We identified 10 patients from 3,132 unique patients (3,431 CT scans). We retrospectively examined CT angiogram of patients with AIS to determine the frequency of concurrent PE in AIS. The period prevalence of PE was 0.32. Seven patients had concurrent PE, whereas three had PE diagnosed 2 days after their AIS presentation. We suspected paradoxical embolism via patent foramen ovale as the cause of stroke in three patients and thrombophilia in four patients. Seven patients had poor outcome including four deaths. CT angiogram stroke protocol images from aortic arch to vertex allows visualization of upper pulmonary arteries and PE detection in AIS.

Although intravenous thrombolysis increases the probability of a good functional outcome in carefully selected patients with acute ischemic stroke, a substantial proportion of patients who receive thrombolysis do not have a good outcome. Several recent trials of mechanical thrombectomy appear to indicate that this treatment may be superior to thrombolysis. We therefore conducted a systematic review and meta-analysis to evaluate the clinical effectiveness and safety of new-generation mechanical thrombectomy devices with intravenous thrombolysis (if eligible) compared with intravenous thrombolysis (if eligible) in patients with acute ischemic stroke caused by a proximal intracranial occlusion. We systematically searched seven databases for randomized controlled trials published between January 2005 and March 2015 comparing stent retrievers or thromboaspiration devices with best medical therapy (with or without intravenous thrombolysis) in adults with acute ischemic stroke. We assessed risk of bias and overall quality of the included trials. We combined the data using a fixed or random effects meta-analysis, where appropriate. We identified 1579 studies; of these, we evaluated 122 full-text papers and included five randomized control trials (n=1287). Compared with patients treated medically, patients who received mechanical thrombectomy were more likely to be functionally independent as measured by a modified Rankin score of 0-2 (odds ratio, 2.39; 95% confidence interval, 1.88-3.04; I2=0%). This finding was robust to subgroup analysis. Mortality and symptomatic intracerebral hemorrhage were not significantly different between the two groups. Mechanical thrombectomy significantly improves functional independence in appropriately selected patients with acute ischemic stroke.

Background: Computed tomography perfusion (CTP) is increasingly being used in the setting of acute ischemic stroke (AIS). The aim of the current study was to compare the prognostic utility of, and inter-observer variation between, baseline appearances on non-contrast CT (using Alberta Stroke Program Early CT score(ASPECTS)) and on CTP for predicting final infarct volume. We also assessed impact of training on interpretation of these images. Methods: Retrospectively, plain head computed tomography (CT) and CTP images at presentation and CT or diffusion imaging on follow up of patients with AIS were analyzed. The lesion volume on different CTP parameters was then correlated with the final infarct volume. This analysis was done by a Neuroradiologist, a stroke Neurologist and a medical student. Kappa statistics and Intra-class correlation coefficients were used for agreement between readers. Pearson correlation coefficients were used.Results: Thirty eight patients with AIS met all inclusion criteria. There was very good agreement among all readers for the CTP parameters. There was only fair agreement for ASPECT score. Correlation coefficient (r-square) between CTP parameters and final infarct volume showed that cerebral blood volume was the best parameter to predict the final infarct volume followed by cerebral blood flow and time to peak. The best reader to predict the final infarct volume on the initial CT perfusion study was the neuroradiologist followed by medical student and stroke neurologist. Conclusions: Cerebral blood volume defect correlated the best with the final infarct volume. There was a very good inter-observer agreement for all the CTP maps in predicting the final infarct volume despite the wide variation in the experience of the readers.

Intravenous tissue plasminogen activator (tPA) is standard treatment for eligible patients with acute ischemic stroke, but may be less effective for very severe strokes caused by proximal intracranial artery occlusions. We report the case of a woman with a devastating stroke who recovered completely following emergency revascularization of an occluded proximal middle cerebral artery using a novel treatment approach that combines both intravenous (IV) and intra-arterial (IA) tPA. This case illustrates the potential value of the combined IV–IA thrombolytic approach, which is an emerging investigational treatment strategy for selected patients with severe acute ischemic stroke.