Kyu Sun Lee

Primary Stent Retrieval for Acute Intracranial Large Artery Occlusion Due to Atherosclerotic Disease

Background and Purpose The goal of stent retriever–based thrombectomy is removal of embolic clots in patients with intracranial large artery occlusion. However, outcomes of stent retrieval may differ between acute arterial occlusions due to intracranial atherosclerotic disease (IAD) and those due to embolism. This case series describes the outcomes of stent retriever–based thrombectomy and rescue treatments in 9 patients with IAD-related occlusion. Methods Among patients who underwent endovascular treatment for acute intracranial large artery occlusion, those in whom stent retrieval was attempted as first-line treatment were included in this review. IAD was defined as significant fixed focal stenosis at the occlusion site, which was evident on final angiographic assessment or observed during endovascular treatment. Results Median number of stent retriever passes was 2 (range, 1-3), and temporary bypass was seen in all patients. Immediate partial recanalization (arterial occlusive lesion grade 2-3) was observed in 7 patients. Immediate modified thrombolysis in cerebral infarction grade 2b-3 was seen in 6 patients, but the lesions often required rescue treatment due to reocclusion or flow insufficiency. In terms of rescue treatments, angioplasty and intra-arterial tirofiban infusion seemed to be effective. Conclusions Our findings suggest that stent retrieval can effectively remove thrombi from stenotic lesions and achieve partial recanalization despite the tendency toward reocclusion in most patients with IAD-related occlusion. Further research into the use of rescue treatments, such as tirofiban infusion and angioplasty, is warranted.

Imaging Predictors for Atherosclerosis-Related Intracranial Large Artery Occlusions in Acute Anterior Circulation Stroke

Hong Il Suh, Ji Man Hong, Kyu Sun Lee, Miran Han, Jin Wook Choi, Jong S. Kim, Andrew M. Demchuk, Jin Soo Lee Department of Neurology, Ajou University School of Medicine, Ajou University Hospital, Suwon, Korea Department of Radiology, Ajou University School of Medicine, Ajou University Medical Center, Suwon, Korea Department of Neurology, Asan Medical Centre, University of Ulsan, Seoul, Korea d Calgary Stroke Program, Departments of Clinical Neurosciences and Radiology, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada Letter to the Editor

Cerebral infarct volume measurements to improve patient selection for endovascular treatment

AbstractPatients who have large cerebral infarctions may not be good candidates for endovascular treatment. Various methods for determining infarct volume have been used in clinical studies. We evaluated the effectiveness of several methods for measuring infarct volume, especially regarding futile outcomes despite endovascular treatment.Patients with acute ischemic stroke in unilateral anterior circulation territory who were treated with intra-arterial thrombectomy were included. For assessing infarct volume, the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) scoring system was applied to images obtained by noncontrast computed tomography (NCCT), postcontrast CT (PCCT), and diffusion-weighted imaging (DWI). DWI stroke volume was semiquantitatively measured with the manually outlined hyperintense lesion. Infarct core volume was calculated with a threshold apparent diffusion coefficient value of 600 × 10–6 mm2/s. Intraclass correlation coefficients (ICC) were estimated to assess inter-reader reliability for ASPECTS scoring and DWI stroke volume. Receiver operating characteristic (ROC) curve analyses, and univariable and multivariable comparative analyses, were performed with each evaluation method to predict futile outcome (modified Rankin Scale score 5–6).The mean age of the included 79 patients was 65.1 ± 15.7 years. Among them, 55 (69.6%) patients demonstrated successful reperfusion after intra-arterial thrombectomy, but 34 (43.0%) patients had futile outcomes. Inter-reader agreement was excellent for measurement of the DWI stroke volume (ICC, 0.973), DWI ASPECTS (0.940), and PCCT ASPECTS (0.859), but was moderate for NCCT ASPECTS (0.694). Regarding prediction of futile outcomes, area under ROC curve was 0.551 on NCCT ASPECTS and it was significantly smaller than that in PCCT ASPECTS (area under ROC 0.651, P = 0.030), DWI ASPECTS (0.733, P = 0.003), DWI stroke volume (0.702, P = 0.022), and infarct core volume (0.702, P = 0.021). Besides old age and high National Institutes of Health Stroke Scale score on admission, MRI parameters such as DWI ASPECTS and infarct core volume indicating large volumes were independently associated with futile outcomes in multivariable analyses.DWI ASPECTS can be a good parameter predicting futility, which is easily measured and has high prediction power.

Useful Computed Tomography Score for Estimation of Early Neurologic Outcome in Post-Cardiac Arrest Patients With Therapeutic Hypothermia

BACKGROUND The Alberta Stroke Program Early CT Score (ASPECTS) is used to assess early ischemic stroke damage. This study compared bilateral ASPECTS (ASPECTS-b) with the gray:white matter ratio (GWR) and quantitative regional abnormality (QRA) to evaluate the prognostic utility of early computed tomography (CT) findings in post-cardiac arrest patients.Methods and Results:Out-of-hospital cardiac arrest patients with return of spontaneous circulation (ROSC) who underwent brain CT (<6 h after onset) and therapeutic hypothermia were recruited from a university hospital over a 2-year period. General demographics, ROSC characteristics, ASPECTS-b (total score=20 points), GWR, and QRA were assessed. Multivariate logistic regression analysis was used to predict neurologic outcome using cerebral performance category (CPC) at 1 month. The study population was divided into good (n=20; CPC 1-2) and poor (n=47; CPC 3-5) outcome groups. The good (vs. poor) outcome group was younger (mean [±SD] age 46.7±11.8 vs. 60.3±17.2 years; P=0.002) and had more initial shockable rhythms (40.0% vs. 8.5%; P=0.002). In addition, the good outcome group had a higher mean ASPECTS-b score (15.3±2.7 vs. 9.0±4.9; P<0.001), despite no differences in QRA and mean GWR. Age and ASPECTS-b were independent predictors of outcome after adjusting for potential confounders. CONCLUSIONS These findings suggest that an initial CT score (ASPECTS-b) could help estimate early neurologic outcomes in post-cardiac arrest patients treated with therapeutic hypothermia.

Intensive medical therapy with therapeutic hypothermia for malignant middle cerebral artery infarction

Intensive medical therapy with therapeutic hypothermia for malignant middle cerebral artery infarction Kyu sun Lee, Jin soo Lee, Ji man Hong Ajou University Medical Center, Republic of Korea Background/Purpose: Malignant middle cerebral artery (MCA) infarction is a large hemispheric infarct caused by proximal MCA or internal carotid artery occlusion with deteriorating progress. Decompressive hemicraniectomy has been regarded effective for increased intracranial pressure. However, it might not be available in elderly or medically unstable patients. Therefore, we compared clinical findings and prognosis between intensive medical therapy with hypothermia (best medical therapy group) and decompressive hemicraniectomy (surgery group) for malignant MCA infarction. Methods: We collected acute MCA infarction patients who underwent brain MRI within 6 hours since onset in a stroke center over 4 years. Malignant MCA infarction was defined as greater than 82 mL on DWI within 6 hours or greater than 145 mL on follow-up DWI or CT. Results: Among total 46 cases, best medical therapy group were 18, and surgery group were 16. Initial National Institutes of Health Stroke Scale (NIHSS) did not differ between the groups. Initial infarct volume on DWI within 6 hours significantly differs between the groups: mean 254.0 ± 107.0 mL in surgery vs 127.2 ± 44.0 mL in best medical therapy (P b .001). NIHSS at discharge, prevalence of good outcome (mRS 0-2), and mortality at 3 months did not differ between the groups. The prevalence of poor outcome (mRS 5-6) at 3 months significantly differ between the groups: 14 (87.5%) in surgery and 16 (53.3%) in best medical therapy (P = .020). Conclusions: This study suggests that intensive medical therapy with hypothermia has lower prevalence of poor outcome than decompressive hemicraniectomy despite relatively similar clinical severity on baseline. Therefore, systematized medical therapy with therapeutic hypothermia might be a feasible strategy to avoid invasive hemicraniectomy in malignant MCA infarction.