Brinjikji, Waleed

AbstractThe purpose of this systematic review and meta‐analysis was to examine clinical outcomes associated with convalescent plasma therapy in COVID‐19 patients. We performed a literature search on PubMed, medRxiv, Web of Science, and Scopus to identify studies published up to December 10th, 2020 that examined the efficacy of convalescent plasma treatment for COVID‐19. The primary endpoints were mortality, clinical improvement, and hospital length of stay. We screened 859 studies that met the search criteria, performed full‐text reviews of 56 articles, and identified 15 articles that fulfilled inclusion criteria for meta‐analysis. The odds of mortality were significantly lower in the convalescent plasma group compared to the control group (OR = 0.59 [95% CI = 0.44; 0.78], P < .001), although results from two key randomized controlled trials did not support the mortality benefit. The odds of clinical improvement were significantly higher in the convalescent plasma group compared to the control group (OR = 2.02 [95% CI = 1.54; 2.65], P < .001). There was no difference in hospital length of stay between the convalescent plasma group and the control group (MD = −0.49 days [95% CI = −3.11; 2.12], P = .713). In all, these data indicate that a mortality benefit with convalescent plasma is unclear, although there remain benefits with convalescent plasma therapy for COVID‐19.

Background Over the past several years there has been increased interest in the use of the Sofia aspiration system (MicroVention, Tustin, California) as a primary aspiration catheter. Objective To perform a multicenter retrospective study examining the efficacy of the Sofia aspiration catheter as a standalone aspiration treatment for large vessel occlusion. Methods Consecutive cases in which the Sofia catheter was used for aspiration thrombectomy for large vessel occlusion were included. Exclusion criteria were the following: (1) Sofia not used for first pass, and (2) a stent retriever used as an adjunct on the first pass. The primary outcome of the study was first pass recanalization (Thrombolysis in Cerebral Infarction (TICI) 2c/3). Secondary outcomes included first pass TICI 2b/3, crossover to other thrombectomy devices, number of passes, time from puncture to recanalization, and complications. Results 323 patients were included. First pass TICI 2c/3 was achieved in 49.8% of cases (161/323). First pass TICI 2b/3 was achieved in 69.7% (225/323) of cases. 74.8% had TICI 2b/3 with the Sofia alone. Crossover to other thrombectomy devices occurred in 29.1% of cases (94/323). The median number of passes was 1 (IQR=1–3). Median time from puncture to recanalization was 26 min (IQR=17–45). Procedure related complications occurred in 3.1% (10/323) of cases. Conclusion Our study highlights the potential advantage of the Sofia aspiration catheter for primary aspiration thrombectomy in acute ischemic stroke. High rates of first pass recanalization with low crossover rates to other thrombectomy devices were achieved. Median procedure time was low, as were procedural complications.

Abstract BACKGROUND Low-grade intracranial dural arteriovenous fistulas (dAVF) have a benign natural history in the majority of cases. The benefit from treatment of these lesions is controversial. OBJECTIVE To compare the outcomes of observation versus intervention for low-grade dAVFs. METHODS We retrospectively reviewed dAVF patients from institutions participating in the CONsortium for Dural arteriovenous fistula Outcomes Research (CONDOR). Patients with low-grade (Borden type I) dAVFs were included and categorized into intervention or observation cohorts. The intervention and observation cohorts were matched in a 1:1 ratio using propensity scores. Primary outcome was modified Rankin Scale (mRS) at final follow-up. Secondary outcomes were excellent (mRS 0-1) and good (mRS 0-2) outcomes, symptomatic improvement, mortality, and obliteration at final follow-up. RESULTS The intervention and observation cohorts comprised 230 and 125 patients, respectively. We found no differences in primary or secondary outcomes between the 2 unmatched cohorts at last follow-up (mean duration 36 mo), except obliteration rate was higher in the intervention cohort (78.5% vs 24.1%, P < .001). The matched intervention and observation cohorts each comprised 78 patients. We also found no differences in primary or secondary outcomes between the matched cohorts except obliteration was also more likely in the matched intervention cohort ( P < .001). Procedural complication rates in the unmatched and matched intervention cohorts were 15.4% and 19.2%, respectively. CONCLUSION Intervention for low-grade intracranial dAVFs achieves superior obliteration rates compared to conservative management, but it fails to improve neurological or functional outcomes. Our findings do not support the routine treatment of low-grade dAVFs.

Background First pass effect (FPE) in mechanical thrombectomy is thought to be associated with good clinical outcomes. Objective To determine FPE rates as a function of thrombectomy technique and to compare clinical outcomes between patients with and without FPE. Methods In July 2020, a literature search on FPE (defined as modified Thrombolysis in Cerebral Infarction (TICI) 2c–3 after a single pass) and modified FPE (mFPE, defined as TICI 2b–3 after a single pass) and mechanical thrombectomy for stroke was performed. Using a random-effects meta-analysis, we evaluated the following outcomes for both FPE and mFPE: overall rates, rates by thrombectomy technique, rates of good neurologic outcome (modified Rankin Scale score ≤2 at day 90), mortality, and symptomatic intracerebral hemorrhage (sICH) rate. Results Sixty-seven studies comprising 16 870 patients were included. Overall rates of FPE and mFPE were 28% and 45%, respectively. Thrombectomy techniques shared similar FPE (p=0.17) and mFPE (p=0.20) rates. Higher odds of good neurologic outcome were found when we compared FPE with non-FPE (56% vs 41%, OR=1.78) and mFPE with non-mFPE (57% vs 44%, OR=1.73). FPE had a lower mortality rate (17% vs 25%, OR=0.62) than non-FPE. FPE and mFPE were not associated with lower sICH rate compared with non-FPE and non-mFPE (4% vs 18%, OR=0.41 for FPE; 5% vs 7%, OR=0.98 for mFPE). Conclusions Our findings suggest that approximately one-third of patients achieve FPE and around half of patients achieve mFPE, with equivalent results throughout thrombectomy techniques. FPE and mFPE are associated with better clinical outcomes.

Background Characterization of acute ischemic stroke (AIS) clots has typically focused on two-dimensional histological analysis of the thrombus. The three-dimensional (3D) architecture and distribution of components within emboli have not been fully investigated. The aim of this study was to examine the composition and microstructure of AIS clots using histology and serial block-face scanning electron microscopy (SBFSEM). Methods As part of the multi-institutional STRIP registry, 10 consecutive AIS emboli were collected from 10 patients treated by mechanical thrombectomy. Histological and immunohistochemical analysis was performed to determine clot composition. SBFSEM was used to assess the ultrastructural organization of the clots and specific features of individual components. Results Quantification of Martius Scarlett Blue stain identified fibrin (44.4%) and red blood cells (RBCs, 32.6%) as the main components. Immunohistochemistry showed a mean platelet and von Willebrand factor content of 23.9% and 11.8%, respectively. The 3D organization of emboli varied greatly depending on the region analyzed. RBC-rich areas were composed mainly of tightly packed RBCs deformed into polyhedrocytes with scant fibrin fibers interwoven between cells. The regions with mixed composition showed thick fibrin fibers along with platelets, white blood cells and RBC clusters. Fibrin-rich areas contained dense fibrin masses with sparse RBC. In three cases, the fibrin formed a grid-like or a sponge-like pattern, likely due to thrombolytic treatment. Segmentation showed that fibrin fibers were thinner and less densely packed in these cases. Conclusions 3D-SEM provides novel and potentially clinically relevant information on clot components and ultrastructure which may help to inform thrombolytic treatment and medical device design.

AbstractEmbolectomy is one of the emergency procedures performed to remove emboli. Assessing the composition of human blood clots is an important diagnostic factor and could provide guidance for an appropriate treatment strategy for interventional physicians. Immunostaining has been used to identity compositions of clots as a gold‐standard procedure, but it is time‐consuming and cannot be performed in situ. Here, we proposed that the optical attenuation coefficient of optical coherence tomography (OCT) can be a reliable indicator as a new imaging modality to differentiate clot compositions. Fifteen human blood clots with multiple red blood cell (RBC) compositions from 21% to 95% were prepared using healthy human whole blood. A homogeneous gelatin phantom experiment and numerical simulation based on the Lambert–Beer's law were examined to verify the validity of the attenuation coefficient estimation. The results displayed that optical attenuation coefficients were strongly correlated with RBC compositions. We reported that attenuation coefficients could be a promising biomarker to guide the choice of an appropriate interventional device in a clinical setting and assist in characterizing blood clots.

Background Initial studies investigating correlations between stroke etiology and clot composition are conflicting and do not account for clot size as determined by area. Radiological studies have shown that cardioembolic strokes are associated with shorter clot lengths and lower clot burden than non-cardioembolic clots. Objective To report the relationship between stroke etiology, extracted clot area, and histological composition at each procedural pass. Methods As part of the multi-institutional RESTORE Registry, the Martius Scarlett Blue stained histological composition and extracted clot area of 612 per-pass clots retrieved from 441 patients during mechanical thrombectomy procedures were quantified. Correlations with clinical and procedural details were investigated. Results Clot composition varied significantly with procedural passes; clots retrieved in earlier passes had higher red blood cell content (H4=11.644, p=0.020) and larger extracted clot area (H4=10.730, p=0.030). Later passes were associated with significantly higher fibrin (H4=12.935, p=0.012) and platelets/other (H4=15.977, p=0.003) content and smaller extracted clot area. Large artery atherosclerotic (LAA) clots were significantly larger in the extracted clot area and more red blood cell-rich than other etiologies in passes 1–3. Cardioembolic and cryptogenic clots had similar histological composition and extracted clot area across all procedural passes. Conclusion LAA clots are larger and associated with a large red blood cell-rich extracted clot area, suggesting soft thrombus material. Cardioembolic clots are smaller in the extracted clot area, consistent in composition and area across passes, and have higher fibrin and platelets/other content than LAA clots, making them stiffer clots. The per-pass histological composition and extracted clot area of cryptogenic clots are similar to those of cardioembolic clots, suggesting similar formation mechanisms.

Purpose To assess whether an asymmetry exists in the prevalence of carotid artery intraplaque hemorrhage (IPH) between right- and left-sided arteries. Materials and methods The records of all patients with atherosclerotic carotid artery disease that underwent neck magnetic resonance angiography imaging with high-resolution plaque sequences between 2017 and 2020 at our institution were retrospectively reviewed. The prevalence of stenosis and IPH was determined for all patients and compared between the left and right carotid arteries of those with unilateral anterior circulation ischemic strokes. Multiple regression analysis was performed to determine potential independent associations of IPH laterality with ischemic strokes. Results A total of 368 patients were included overall and 241 were male (65.4%). There were a total of 125 asymptomatic patients and 211 patients with unilateral anterior circulation ischemic strokes. Of patients with ischemic strokes, 55.5% had left-sided strokes compared with 44.5% who had right-sided strokes ( p = 0.03). Patients with left-sided strokes had a higher prevalence of ipsilateral IPH than those with right-sided strokes (64.1% versus 36.2%, p < 0.0001), despite similar degrees of stenosis. Both age (odds ratio (OR): 1.0; 95% confidence interval (CI): 1.0–1.1; p = 0.007) and the presence of left-sided IPH (OR: 3.2; 95% CI: 1.5–6.8; p = 0.003) were independently associated with unilateral ischemic strokes. Conclusions Left-sided plaques more frequently have IPH and may be more likely to result in ipsilateral ischemic strokes compared with right-sided plaques. The underlying mechanism of asymmetric distribution of IPH between right and left carotids remains unclear.

Background and Purpose: Few community-based studies investigating young adult strokes exist. The aim of this study was to determine the diagnostic yield of head and neck CTA in evaluation of anterior circulation ischemic stroke in young adults. Materials and Methods: This retrospective review is limited to patients between the ages of 18-50 presenting to the Mayo Clinic Rochester emergency department or referred from smaller institutions in adjacent counties. Patients with posterior circulation infarcts, amaurosis fugax, central retinal artery occlusion or transient ischemic attacks were excluded. The presence of carotid dissection, webs, plaque, or other high-risk lesions were recorded. Results: A total of 136 patients met inclusion criteria. Mean degree of carotid stenosis ipsilateral to infarct was 14.1%, compared to 6.5% on the contralateral side (p = .006). Ipsilateral mean carotid wall thickness measured .79 mm, compared to contralateral thickness of .80 mm (p = .51). Ipsilateral low-density plaque was observed in 22 patients (16.2%), and 21 patients (15.4%) on the contralateral side (p = .87). Ipsilateral calcified plaque was observed in 37 patients (27.2%), and 29 patients (21.3%) on the contralateral side (p = .31). 20 (14.7%) ipsilateral dissections were noted, compared to 4 (2.9%) contralateral dissections (p = .001). 3 (2.2%) ipsilateral carotid webs were identified, compared to 0 contralateral webs (p = .25). Conclusion: Carotid dissection was the most common cause of anterior circulation infarct identified on cervical CTA in this population. Carotid webs and atherosclerosis were not common findings.