Diffusion basis spectrum imaging and diffusion tensor imaging predict persistent black hole formation in multiple sclerosis.

BACKGROUND AND OBJECTIVES: Diffusion basis spectrum imaging (DBSI) extracts multiple anisotropic and isotropic diffusion tensors, providing greater histopathologic specificity than diffusion tensor imaging (DTI). Persistent black holes (PBH) represent areas of severe tissue damage in multiple sclerosis (MS), and a high PBH burden is associated with worse MS disability. This study evaluated the ability of DBSI and DTI to predict which acute contrast-enhancing lesions (CELs) would persist as T1 hypointensities (i.e. PBHs) 12 months later. We expected that a higher radial diffusivity (RD), representing demyelination, and higher DBSI-derived isotropic non-restricted fraction, representing edema and increased extracellular space, of the acute CEL would increase the likelihood of future PBH development. METHODS: In this prospective cohort study, relapsing MS patients with ≥1 CEL(s) underwent monthly MRI scans for 4 to 6 months until gadolinium resolution. DBSI and DTI metrics were quantified when the CEL was most conspicuous during the monthly scans. To determine whether the CEL became a PBH, a follow-up MRI was performed at least 12 months after the final monthly scan. RESULTS: The cohort included 20 MS participants (median age 33 years; 13 women) with 164 CELs. Of these, 59 (36 %) CELs evolved into PBHs. At Gd-max, DTI RD and AD of all CELs increased, and both metrics were significantly elevated for CELs which became PBHs, as compared to non-black holes (NBHs). DTI RD above 0.74 conferred an odds ratio (OR) of 7.76 (CI 3.77-15.98) for a CEL becoming a PBH (AUC 0.80, CI 0.73-0.87); DTI axial diffusivity (AD) above 1.22 conferred an OR of 7.32 (CI 3.38-15.86) for becoming a PBH (AUC 0.75, CI 0.66-0.83). DBSI RD and AD did not predict PBH development in a multivariable model. At Gd-max, DBSI restricted fraction decreased and DBSI non-restricted fraction increased in all CELs, and both metrics were significantly different for CELs which became PBHs, as compared to NBHs. A CEL with a DBSI non-restricted fraction above 0.45 had an OR of 4.77 (CI 2.35-9.66) for becoming a PBH (AUC 0.74, CI 0.66-0.81); a CEL with a DBSI restricted fraction below 0.07 had an OR of 9.58 (CI 4.59-20.02) for becoming a PBH (AUC 0.80, 0.72-0.87). CONCLUSION: Our findings suggest that greater degree of edema/extracellular space in a CEL is a predictor of tissue destruction, as evidenced by PBH evolution.

Common Design and Data Elements Reported on Idiopathic Intracranial Hypertension Trials: A Systematic Review.

BACKGROUND: There are an increasing number of controlled clinical trials and prospective studies, ongoing and recently completed, regarding management options for idiopathic intracranial hypertension (IIH). We present a Common Design and Data Element (CDDE) analysis of controlled and prospective IIH studies with the aim of aligning essential design and recommending data elements in future trials and enhancing data synthesis potential in IIH trials. METHODS: We used PubMed and ClinicalTrials.gov to screen for ongoing and published trials assessing treatment modalities in people with IIH. After our search, we used the Nested Knowledge AutoLit platform to extract pertinent information regarding each study. We examined outputs from each study and synthesized the data elements to determine the degree of homogeneity between studies. RESULTS: The most CDDE for inclusion criteria was the modified Dandy criteria for diagnosis of IIH, used in 9/14 studies (64%). The most CDDE for outcomes was change in visual function, reported in 12/14 studies (86%). Evaluation of surgical procedures (venous sinus stenting, cerebrospinal fluid shunt placement, and others) was more common, seen in 9/14 studies (64%) as compared with interventions with medical therapy 6/14 (43%). CONCLUSIONS: Although all studies have similar focus to improve patient care, there was a high degree of inconsistency among studies regarding inclusion criteria, exclusion criteria, and outcomes measures. Furthermore, studies used different time frames to assess outcome data elements. This heterogeneity will make it difficult to achieve a consistent standard, and thus, making secondary analyses and meta-analyses less effective in the future. Consensus on design of trials is an unmet research need for IIH.

CT perfusion to measure venous outflow in acute ischemic stroke in patients with a large vessel occlusion.

BACKGROUND: Robust venous outflow (VO) profiles, measured by degree of venous opacification on pre-thrombectomy CT angiography (CTA) studies, are strongly correlated with favorable outcomes in patients with large vessel occlusion acute ischemic stroke treated by thrombectomy. However, VO measurements are laborious and require neuroimaging expertise. OBJECTIVE: To develop a semi-automated method to measure VO using CTA and CT perfusion imaging studies. METHODS: We developed a graphical interface using The Visualization Toolkit, allowing for voxel selection at the confluence and bilateral internal cerebral veins on CTA along with arterial input functions (AIFs) from both internal carotid arteries. We extracted concentration-time curves from the CT perfusion study at the corresponding locations associated with AIF and venous output function (VOF). Outcome analyses were primarily conducted by the Mann-Whitney U and Jonckheere-Terpstra tests. RESULTS: Segmentation at the pre-selected AIF and VOF locations was performed on a sample of 97 patients. 65 patients had favorable VO (VO+) and 32 patients had unfavorable VO (VO-). VO+ patients were found to have a significantly shorter VOF time to peak (8.26; 95% CI 7.07 to 10.34) than VO- patients (9.44; 95% CI 8.61 to 10.91), P=0.007. No significant difference was found in VOF curve width and the difference in time between AIF and VOF peaks. CONCLUSIONS: Time to peak of VOF at the confluence of sinuses was significantly associated with manually scored venous outflow. Further studies should aim to understand better the association between arterial inflow and venous outflow, and capture quantitative metrics of venous outflow at other locations.

First-pass effect in posterior acute ischemic stroke undergoing endovascular thrombectomy: A systematic review and meta-analysis.

OBJECTIVES: First-pass effect (FPE) has been shown to be a predictor of favorable clinical outcomes following endovascular thrombectomy (EVT) for acute ischemic stroke (AIS) in the anterior circulation. Literature regarding FPE for posterior circulation AIS is sparse; we conducted a systematic review and meta-analysis to explore FPE in posterior circulation stroke undergoing EVT. MATERIALS AND METHODS: We conducted a systematic review of the English literature in PubMed, Embase, Scopus, and Web of Science. FPE was defined as thrombolysis in cerebral infarction (TICI) 2c-3 and modified FPE (mFPE) was defined as TICI 2b-3 in one pass. Definitions of non-FPE and non-mFPE varied among studies. The primary outcome of interest was modified Rankin Scale (mRS) 0-2. Secondary outcomes of interest were mRS 0-3, symptomatic intracranial hemorrhage (sICH), and mortality. We calculated odds ratios (OR) and corresponding 95% confidence intervals (CI). Heterogeneity was assessed with Q statistic and I2 test. RESULTS: Seven studies with 417 patients in the mFPE group, 942 in the non-mFPE group, 545 in the FPE group, and 1023 in the non-FPE group were included. Overall, FPE was associated with greater rates of 90-day mRS 0-2 (OR= 2.78, 95% CI= 2.11-3.65; P-value< 0.001) and mRS 0-3 (OR= 2.67, 95% CI= 1.98-3.60; P-value< 0.001); however, there was significant heterogeneity among studies for both mRS 0-2 (I2= 69%; P-value< 0.001) and mRS 0-3 (I2= 69%; P-value< 0.001). FPE and non-FPE were associated with similar rates of sICH (OR= 0.65, 95% CI= 0.40-1.07; P-value= 0.09), and no heterogeneity was observed (I2= 0%; P-value= 0.95). FPE was associated with lower rates of mortality (OR= 0.44, 95% CI= 0.33-0.58; P-value< 0.001), although heterogeneity was observed (I2= 58%; P-value= 0.01). CONCLUSIONS: FPE is associated with favorable clinical outcomes in patients undergoing EVT for posterior circulation AIS. Future studies should work to further quantify the impact of FPE on outcomes in the posterior circulation.

Hypoperfusion intensity ratio as a predictor of outcomes after thrombectomy triage: A call for data homogeneity.

BACKGROUND: Collateral blood flow markers have been associated with outcomes after thrombectomy in patients presenting with acute ischemic stroke due to large vessel occlusion (AIS-LVO). Hypoperfusion intensity ratio (HIR), a metric reflecting tissue level collaterals, is one such marker with the potential to delineate patients who do and do not do well after thrombectomy. We determined if HIR correlated with successful reperfusion after thrombectomy. METHODS: Using Nested Knowledge, we screened literature for studies comparing patients with favorable versus unfavorable HIR, distinguished by a cutoff of 0.4, who underwent thrombectomy triage. The primary outcome was reperfusion success, as measured by thrombolysis in cerebral infarction ≥2b and secondary outcomes included rate of symptomatic intracranial hemorrhage, mortality at 90 days, and modified Rankin scale scores 0-2 at 90 days. A random effects model was used to compute pooled prevalence rates and their corresponding 95% confidence intervals (CI). RESULTS: Three studies with 973 patients, 496 with favorable HIR, and 477 with unfavorable HIR were included in this meta-analysis. The odds of reperfusion success were not significantly different between patients who had favorable versus unfavorable HIR (OR 0.96, 95% CI: 0.31-3.04) across two of the studies. Analysis of the remaining outcome variables was precluded by significant heterogeneity in data element reporting. CONCLUSIONS: This meta-analysis was considerably limited by heterogeneity. Future meta-analyses on this topic, and other topics in the field of neurointervention would benefit from improved harmonization of study design and data element reporting.

Endovascular thrombectomy for ischemic stroke with large core volume: An updated, post-TESLA systematic review and meta-analysis of the randomized trials.

BACKGROUND: Limited randomized controlled trials (RCTs) have been performed comparing endovascular thrombectomy (EVT) to medical therapy (MEDT) for acute ischemic stroke with extensive baseline ischemic injury (AIS-EBI). We conducted a systematic review and meta-analysis of RCTs reporting EVT for AIS-EBI. METHODS: Using the Nested Knowledge AutoLit software, we conducted a systematic literature review from inception to 12 February 2023 within Web of Science, Embase, Scopus, and PubMed databases. Results of the TESLA trial were included on 10 June 2023. We included RCTs that compared EVT to MEDT for AIS with large ischemic core volume. The primary outcome of interest was a modified Rankin Score (mRS) 0-2. Secondary outcomes of interest included early neurological improvement (ENI), mRS 0-3, thrombolysis in cerebral infarction (TICI) 2b-3, symptomatic intracranial hemorrhage (sICH), and mortality. A random-effects model was used to calculate risk ratios (RRs) and their corresponding 95% confidence intervals (CIs). RESULTS: We included four RCTs with 1310 patients, 661 of whom underwent EVT and 649 of whom were treated with MEDT. EVT was associated with greater rates of mRS 0-2 (RR = 2.33, 95% CI = 1.75-3.09; P-value < 0.001), mRS 0-3 (RR = 1.68, 95% CI = 1.33-2.12; P-value < 0.001), and ENI (RR = 2.24, 95% CI = 1.55-3.24; P-value < 0.001). Rates of sICH (RR = 1.99, 95% CI = 1.07-3.69; P-value = 0.03) were greater in the EVT group. Mortality (RR = 0.98, 95% CI = 0.83-1.15; P-value = 0.79) was comparable between the EVT and MEDT groups. The rate of successful reperfusion in the EVT group was 79.9% (95% CI = 75.6-83.6). CONCLUSIONS: Although the rate of sICH was greater in the EVT group, EVT conferred a greater clinical benefit to MEDT for AIS-EBI based on available RCTs.

Endovascular Therapy for Stroke Presenting Beyond 24 Hours: A Systematic Review and Meta-analysis.

Importance: Previous randomized clinical trials (RCTs) have supported the use of endovascular therapy (EVT) in late-window acute ischemic stroke (AIS; 6-24 hours). However, little is known about the use of EVT in very late-window AIS (>24 hours). Objective: To examine outcomes following EVT for very late-window AIS. Data Sources: A systematic review of the English language literature was conducted using Web of Science, Embase, Scopus, and PubMed to search for articles published from database inception until December 13, 2022. Study Selection: This systematic review and meta-analysis included published studies regarding very late-window AIS treated with EVT. Multiple reviewers screened studies, and an extensive manual search of the references of included articles was performed to identify any missed articles. Of the 1754 initially retrieved studies, 7 published between 2018 and 2023 were ultimately included. Data Extraction and Synthesis: Data were extracted independently by multiple authors and evaluated for consensus. Data were pooled using a random-effects model. This study is reported per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guideline, and the protocol was prospectively registered with PROSPERO. Main Outcomes and Measures: The primary outcome of interest was functional independence, as assessed with 90-day modified Rankin Scale (mRS) scores (0-2). Secondary outcomes included thrombolysis in cerebral infarction (TICI) scores (2b-3 or 3), symptomatic intracranial hemorrhage (sICH), 90-day mortality, early neurological improvement (ENI), and early neurological deterioration (END). Frequencies and means were pooled with the corresponding 95% CIs. Results: This review included 7 studies involving a total of 569 patients. The mean baseline National Institutes of Health Stroke Scale score was 13.6 (95% CI, 11.9-15.5), and the mean Alberta Stroke Program Early CT Score was 7.9 (95% CI, 7.2-8.7). The mean time from last known well and/or onset to puncture was 46.2 hours (95% CI, 32.4-65.9 hours). Frequencies for the primary and secondary outcomes were 32.0% (95% CI, 24.7%-40.2%) for functional independence (90-day mRS scores of 0-2) and 81.9% (95% CI, 78.5%-84.9%) for TICI scores of 2b to 3, 45.3% (95% CI, 36.6%-54.4%) for TICI scores of 3, 6.8% (95% CI, 4.3%-10.7%) for sICH, and 27.2% (95% CI, 22.9%-31.9%) for 90-day mortality. In addition, frequencies were 36.9% (95% CI, 26.4%-48.9%) for ENI and 14.3% (95% CI, 7.1%-26.7%) for END. Conclusions and Relevance: In this review, EVT for very late-window AIS was associated with favorable frequencies of 90-day mRS scores of 0 to 2 and TICI scores of 2b to 3 and with low frequencies of 90-day mortality and sICH. These results suggest that EVT may be safe and associated with improved outcomes for very late-window AIS, although RCTs and prospective, comparative studies are needed to determine which patients may benefit from very late intervention.

CT Perfusion vs Noncontrast CT for Late Window Stroke Thrombectomy: A Systematic Review and Meta-analysis.

BACKGROUND AND OBJECTIVES: Patients with acute ischemic stroke (AIS) treated with endovascular thrombectomy (EVT) in the late window (6-24 hours) can be evaluated with CT perfusion (CTP) or with noncontrast CT (NCCT) only. Whether outcomes differ depending on the type of imaging selection is unknown. We conducted a systematic review and meta-analysis comparing outcomes between CTP and NCCT for EVT selection in the late therapeutic window. METHODS: This study is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses 2020 guidelines. A systematic literature review of the English language literature was conducted using Web of Science, Embase, Scopus, and PubMed databases. Studies focusing on late-window AIS undergoing EVT imaged through CTP and NCCT were included. Data were pooled using a random-effects model. The primary outcome of interest was rate of functional independence, defined as modified Rankin scale 0-2. The secondary outcomes of interest included rates of successful reperfusion, defined as thrombolysis in cerebral infarction 2b-3, mortality, and symptomatic intracranial hemorrhage (sICH). RESULTS: Five studies with 3,384 patients were included in our analysis. There were comparable rates of functional independence (odds ratio [OR] 1.03, 95% CI 0.87-1.22; p = 0.71) and sICH (OR 1.09, 95% CI 0.58-2.04; p = 0.80) between the 2 groups. Patients imaged with CTP had higher rates of successful reperfusion (OR 1.31, 95% CI 1.05-1.64; p = 0.015) and lower rates of mortality (OR 0.79, 95% CI 0.65-0.96; p = 0.017). DISCUSSION: Although recovery of functional independence after late-window EVT was not more common in patients selected by CTP when compared with patients selected by NCCT only, patients selected by CTP had lower mortality.

Mechanical thrombectomy alone versus with thrombolysis for ischemic stroke: A meta-analysis of randomized trials.

INTRODUCTION: Mechanical thrombectomy (MT) is the standard of care in eligible patients presenting with acute ischemic stroke (AIS). The question of whether intravenous thrombolysis (IVT) improves outcomes in conjunction with MT remains unanswered. We performed a systematic review and meta-analysis of published randomized controlled trials (RCT) to explore outcomes of MT with and without IVT. METHODS: Following the PRISMA guidelines, a systematic literature review of the English language literature was conducted using PubMed, Embase, Web of science, and Scopus. Outcomes of interest included 90-day modified Rankin Scale (mRS) 0-2, thrombolysis in cerebral infarction (TICI) score 2b-3, symptomatic intracranial hemorrhage (sICH), distal embolization, and mortality. We calculated pooled risk ratios (RRs) and their corresponding 95% confidence intervals (CI). RESULTS: Six RCTs with 2334 patients compared outcomes of patients treated with MT alone and MT with IVT. Both treatments resulted in comparable rates of mRS 0-2 (RR = 0.96, 95% CI = 0.88-1.04; p-value = 0.282), sICH (RR = 0.80, 95% CI = 0.55-1.17; p-value = 0.253), mortality at 90-days (RR = 1.06, 95% CI = 0.88-1.28; p-value = 0.529), and distal embolization (RR = 1.10, 95% CI = 0.79-1.52; p-value = 0.572). MT alone was associated with a lower rate of TICI 2b-3 compared to MT with IVT (RR = 0.96, 95% CI = 0.93-0.99; p-value = 0.006). CONCLUSIONS: In this meta-analysis of six RCTs, MT alone was comparable to MT plus IVT for mRS 0-2, sICH, mortality, and distal embolization; however, MT alone resulted in lower rates of TICI 2b-3. Further trials are needed to determine which patient populations benefit from MT plus IVT and to increase the power of future meta-analyses.

The diagnostic performance of artificial intelligence algorithms for identifying M2 segment middle cerebral artery occlusions: A systematic review and meta-analysis.

BACKGROUND: Artificial intelligence (AI)-based algorithms have been developed to facilitate rapid and accurate computed tomography angiography (CTA) assessment in proximal large vessel occlusion (LVO) acute ischemic stroke, including internal carotid artery and M1 occlusions. In clinical practice, however, the detection of medium vessel occlusion (MeVO) represents an ongoing diagnostic challenge in which the added value of AI remains unclear. PURPOSE: To assess the diagnostic performance of AI platforms for detecting M2 occlusions. METHODS: Studies that report the diagnostic performance of AI-based detection of M2 occlusions were screened, and sensitivity and specificity data were extracted using the semi-automated AutoLit software (Nested Knowledge, MN) platform. STATA (version 16 IC; Stata Corporation, College Station, Texas, USA) was used to conduct all analyses. RESULTS: Eight studies with a low risk of bias and significant heterogeneity were included in the quantitative and qualitative synthesis. The pooled estimates of sensitivity and specificity of AI platforms for M2 occlusion detection were 64% (95% CI, 53 to 74%) and 97% (95% CI, 84 to 100%), respectively. The area under the curve (AUC) in the SROC curve was 0.79 (95% CI, 0.74 to 0.83). CONCLUSION: The current performance of the AI-based algorithm makes it more suitable as an adjunctive confirmatory tool rather than as an independent one for M2 occlusions. With the rapid development of such algorithms, it is anticipated that newer generations will likely perform much better.

Comparing Tigertriever 13 to other thrombectomy devices for distal medium vessel occlusion: A systematic review and meta-analysis.

BACKGROUND: There is limited evidence on the optimal endovascular strategy for treatment of distal medium-vessel occlusions (DMVO). The low-profile Tigertriever 13 stent-triever shows early promise as an adaptable device that can navigate the distal vasculature without increasing complication risk in DMVO. METHODS: Using Nested Knowledge, we screened literature for RCTs and cohort studies on the endovascular treatment of DMVO. The primary outcome was reperfusion success, as measured by thrombolysis in cerebral infarction (TICI) ≥ 2b and secondary outcomes included rate of symptomatic intracranial hemorrhage (sICH), mortality at 90 days, and modified Rankin scale (mRS) scores 0-2 at 90 days. A random-effects model was used to compute pooled prevalence rates and their corresponding 95% confidence intervals (CI). RESULTS: Eleven studies with 1402 patients, 167 patients treated by Tigertriever 13 and 1235 patients treated by other devices, were included in the meta-analysis. The rate of reperfusion success was similar in patients treated by Tigertriever 13 (83.2% [95% CI: 71.5-96.7%]) versus other devices (81.6% [95% CI: 75.3-88.4%], p > 0.05). The rate of sICH was also similar in patients treated by Tigertriever 13 (7.2% [95% CI: 4.1-12.5%]) versus other devices (6.9% [95% CI: 5.5-8.8%]). There was significant heterogeneity in the reporting of mortality and mRS. CONCLUSIONS: Tigertriever 13 had similar rates of reperfusion success and sICH as other devices used for the treatment of DMVO. Heterogeneity in data element reporting prevented further analyses. Further studies evaluating Tigertriever 13 and other potential devices in DMVO should attempt to harmonize data element reporting.

Aspiration thrombectomy versus stent retriever thrombectomy alone for acute ischemic stroke: evaluating the overlapping meta-analyses.

BACKGROUND: Previous studies comparing a direct aspiration first pass technique (ADAPT) and stent retrievers have inconsistent methodologies and data reporting, limiting the ability to accurately assimilate data from different studies that would inform treatment of acute ischemic stroke (AIS) treatment. OBJECTIVE: To conduct a systematic review to discuss and compare the findings of all relevant meta-analysis studies comparing the efficacy of the ADAPT and stent retriever techniques. METHODS: The study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), where meta-analyses comparing the efficacy of the ADAPT technique and stent retrievers in the treatment of AIS were included. We extracted all relevant data from the included studies and assessed the quality of the included meta-analyses using the Assessment of Multiple Systematic Review (AMSTAR-2). RESULTS: Seven relevant studies met our inclusion criteria and were suitable for the qualitative synthesis. All included studies obtained data from randomized controlled trials (RCTs) and observational investigations (including levels II, III, and IV). At the same time, none of them used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) for quality assessment. In accordance with AMSTAR-2, two studies were rated 'high', while the other five were rated 'moderate'. CONCLUSIONS: Present evidence is insufficient to clarify the superiority of one modality over the other. Further RCTs on this comparison must be conducted prior to designing further meta-analyses or making conclusive interpretations. Procedure duration and cost should be taken into consideration for any future studies.

Hypoperfusion Intensity Ratio Is Correlated With the Risk of Parenchymal Hematoma After Endovascular Stroke Treatment.

BACKGROUND: Parenchymal hematoma (PH) is a major complication after endovascular treatment (EVT) for ischemic stroke. The hypoperfusion intensity ratio (HIR) represents a perfusion parameter reflecting arterial collateralization and cerebral microperfusion in ischemic brain tissue. We hypothesized that HIR correlates with the risk of PH after EVT. METHODS: Retrospective multicenter cohort study of patients with large vessel occlusion who underwent EVT between 2013 and 2021 at one of the 2 comprehensive stroke centers (University Medical Center Hamburg-Eppendorf, Germany and Stanford University School of Medicine, CA). HIR was automatically calculated on computed tomography perfusion studies as the ratio of brain volume with time-to-max (Tmax) delay >10 s over volume with Tmax >6 s. Reperfusion hemorrhages were assessed according to the Heidelberg Bleeding Classification. Primary outcome was PH occurrence (PH+) or absence (PH-) on follow-up imaging. Secondary outcome was good clinical outcome defined as a 90-day modified Rankin Scale score of 0 to 2. RESULTS: A total of 624 patients met the inclusion criteria. We observed PH in 91 (14.6%) patients after EVT. PH+ patients had higher HIR on admission compared with PH- patients (median, 0.6 versus 0.4; P<0.001). In multivariable regression, higher admission blood glucose (adjusted odds ratio [aOR], 1.08 [95% CI, 1.04-1.13]; P<0.001), extensive baseline infarct defined as Alberta Stroke Program Early CT Score ≤5 (aOR, 2.48 [1.37-4.42]; P=0.002), and higher HIR (aOR, 1.22 [1.09-1.38]; P<0.001) were independent determinants of PH after EVT. Both higher HIR (aOR, 0.83 [0.75-0.92]; P<0.001) and PH on follow-up imaging (aOR, 0.39 [0.18-0.80]; P=0.013) were independently associated with lower odds of achieving good clinical outcome. CONCLUSIONS: Poorer (higher) HIR on admission perfusion imaging was strongly associated with PH occurrence after EVT. HIR as a surrogate for cerebral microperfusion might reflect tissue vulnerability for reperfusion hemorrhages. This automated and quickly available perfusion parameter might help to assess the need for intensive medical care after EVT.

Poor venous outflow profiles increase the risk of reperfusion hemorrhage after endovascular treatment.

To investigate whether unfavorable cerebral venous outflow (VO) predicts reperfusion hemorrhage after endovascular treatment (EVT), we conducted a retrospective multicenter cohort study of patients with acute ischemic stroke and large vessel occlusion (AIS-LVO). 629 AIS-LVO patients met inclusion criteria. VO profiles were assessed on admission CT angiography using the Cortical Vein Opacification Score (COVES). Unfavorable VO was defined as COVES ≤ 2. Reperfusion hemorrhages on follow-up imaging were subdivided into no hemorrhage (noRH), hemorrhagic infarction (HI) and parenchymal hematoma (PH). Patients with PH and HI less frequently achieved good clinical outcomes defined as 90-day modified Rankin Scale scores of ≤ 2 (PH: 13.6% vs. HI: 24.6% vs. noRH: 44.1%; p < 0.001). The occurrence of HI and PH on follow-up imaging was more likely in patients with unfavorable compared to patients with favorable VO (HI: 25.1% vs. 17.4%, p = 0.023; PH: 18.3% vs. 8.5%; p = <0.001). In multivariable regression analyses, unfavorable VO increased the likelihood of PH (aOR: 1.84; 95% CI: 1.03-3.37, p = 0.044) and HI (aOR: 2.05; 95% CI: 1.25-3.43, p = 0.005), independent of age, sex, admission National Institutes Health Stroke Scale scores and arterial collateral status. We conclude that unfavorable VO was associated with the occurrence of HI and PH, both related to worse clinical outcomes.

Mechanical Thrombectomy via Transradial Approach for Posterior Circulation Stroke: A Systematic Review and Meta-Analysis.

Mechanical thrombectomy for acute ischemic stroke (AIS) is traditionally performed via transfemoral access. While the majority of AISs are due to anterior circulation large vessel occlusions (AC-LVO), we performed a systematic review and meta-analysis to examine the feasibility of and outcomes following a transradial artery access for posterior circulation large vessel occlusion (PC-LVO) strokes. A systematic literature review of the English language literature was conducted using PubMed, MEDLINE, and Embase as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Outcomes of interest included 90-day modified Rankin scale (mRS) 0-2, puncture to recanalization time, and thrombolysis in cerebral infarction (TICI) scores 2b/3 and 3. We calculated pooled event rates and their corresponding 95% confidence intervals (CI) for all outcomes. We included seven studies with 68 patients in our analysis. All patients underwent mechanical thrombectomy via transradial artery access for AIS due to PC-LVO. The pooled meantime of puncture to recanalization was 29.19 (95% CI=24.05 to 35.42) minutes. Successful recanalization (TICI2b/3) was achieved in 98.69% (95% CI=93.50 to 100) of patients and complete recanalization (TICI 3) in 52.16% (95% CI=34.18 to 79.60) of the patients. Overall, 56.84% (95% CI=41.26 to 78.30) of patients achieved mRS 0-2. Transradial artery access for mechanical thrombectomy for PC-LVO stroke displays early promise and feasibility, particularly regarding very high rates of successful recanalization and low puncture to recanalization time.

Mechanical thrombectomy in anterior vs. posterior circulation stroke: A systematic review and meta-analysis.

BACKGROUND: High-quality evidence exists for mechanical thrombectomy (MT) treatment of acute ischemic stroke (AIS) due to large vessel occlusion of the anterior circulation (AC-LVO). The evidence for MT treatment of posterior circulation large vessel occlusion (PC-LVO) is weaker, largely drawn from lower quality studies specific to PC-LVO and extrapolated from findings in AC-LVO, and ambiguous with regards to technical success. We performed a systematic review and meta-analysis to compare the technical success and functional outcomes of MT in PC-LVO versus AC-LVO patients. METHODS: We identified comparative studies reporting on patients treated with MT in AC-LVO versus PC-LVO. The primary outcome of interest was thrombolysis in cerebral infarction (TICI) ≥ 2b. Secondary outcomes included rates of TICI 3, 90-day functional independence, first-pass-effect, average number of passes, and 90-day mortality. A separate random effects model was fit for each outcome measure. RESULTS: Twenty studies with 12,911 patients, 11,299 (87.5%) in the AC-LVO arm and 1612 (12.5%) in the PC-LVO arm, were included. AC-LVO and PC-LVO patients had comparable rates of successful recanalization [OR = 1.02 [95% CI: 0.79-1.33], p = 0.848). However, the AC-LVO group had greater odds of 90-day functional independence (OR = 1.26 [95% CI: 1.00; 1.59], p = 0.050) and lower odds of 90-day mortality (OR = 0.58 [95% CI: 0.43; 0.79], p = 0.002). CONCLUSIONS: MT achieves similar rates of recanalization with a similar safety profile in PC-LVO and AC-LVO patients. Patients with PC-LVO are less likely to achieve functional independence after MT. Future studies should identify PC-LVO patients who are likely to achieve favourable functional outcomes.

Common data elements reported on middle meningeal artery embolization in chronic subdural hematoma: an interactive systematic review of recent trials.

Cross study heterogeneity has limited the evidence based evaluation of middle meningeal artery embolization (MMAE) as a treatment for chronic subdural hematoma (CSDH). Ongoing trials and prospective studies suggest that heterogeneity in upcoming publications may detract from subsequent meta-analyses and systemic reviews. This study aims to describe this data heterogeneity to promote harmonization with common data elements (CDEs) in publications. ClinicalTrials.gov and PubMed were searched for published or ongoing prospective trials of MMAE. The Nested Knowledge AutoLit living review platform was utilized to classify endpoints from randomized control trials (RCTs) and prospective cohort studies comparing MMAE with other treatments. The qualitative synthesis feature was used to determine cross study overlap of outcome related data elements. Eighteen studies were included: 12 RCTs, two non-randomized controlled studies, two prospective single arm trials, one combined prospective and retrospective controlled study, and one prospective cohort study. The most commonly reported data element was recurrence (15/18), but seven heterogenous (non-comparable) definitions were used for 'recurrence'. Mortality was reported in 10/18 studies, but no common timepoint was reported in more than four studies. Re-intervention and CSDH volume were reported in eight studies, CSDH width in seven, and no other outcome was common across more than five studies. There was significant heterogeneity in data element collection even among prospective registered trials of MMAE. Even among CDEs, variation in definition and timepoints prevented harmonization. A standardized approach based on CDEs may be necessary to facilitate future meta-analyses and evidence driven evaluation of MMAE treatment of CSDH.

Successful mechanical thrombectomy in acute ischemic stroke: revascularization grade and functional independence.

Most studies define the technical success of endovascular thrombectomy (EVT) as a Thrombolysis in Cerebral Infarction (TICI) revascularization grade of 2b or higher. However, growing evidence suggests that TICI 3 is the best angiographic predictor of improved functional outcomes. To assess the association between successful TICI revascularization grades and functional independence at 90 days, we performed a systematic review and network meta-analysis of thrombectomy studies that reported TICI scores and functional outcomes, measured by the modified Rankin Scale, using the semi-automated AutoLit software platform. Forty studies with 8691 patients were included in the quantitative synthesis. Across TICI, modified TICI (mTICI), and expanded TICI (eTICI), the highest rate of good functional outcomes was observed in patients with TICI 3 recanalization, followed by those with TICI 2c and TICI 2b recanalization, respectively. Rates of good functional outcomes were similar among patients with either TICI 2c or TICI 3 grades. On further sensitivity analysis of the eTICI scale, the rates of good functional outcomes were equivalent between eTICI 2b50 and eTICI 2b67 (OR 0.81, 95% CI 0.52 to 1.25). We conclude that near complete or complete revascularization (TICI 2c/3) is associated with higher rates of functional outcomes after EVT.

Endovascular thrombectomy after acute ischemic stroke of the basilar artery: a meta-analysis of four randomized controlled trials.

BACKGROUND: Previous randomized controlled trials (RCTs) and meta-analyses were underpowered to demonstrate the superiority of endovascular thrombectomy (EVT) over medical therapy (MEDT) in the treatment of acute ischemic stroke due to large vessel occlusion of the posterior circulation (PC-LVO). We performed an updated systematic review and meta-analysis after the publication of the BAOCHE and ATTENTION trials to determine whether EVT can benefit patients presenting with PC-LVO. METHODS: Using Nested Knowledge, we screened literature for RCTs on EVT in PC-LVO. The primary outcome was 90-day modified Rankin Scale (mRS) score 0-3, and secondary outcomes included 90-day mRS score 0-2, 90-day mortality, and rate of symptomatic intracranial hemorrhage (sICH). A random-effects model was used to compute rate ratios (RRs) and their corresponding 95% confidence intervals (CIs). RESULTS: Four RCTs with 988 patients, 556 patients in the EVT arm and 432 patients in the MEDT arm, were included in the meta-analysis. EVT resulted in significantly higher rates of mRS score 0-3 (RR=1.54; 95% CI 1.16 to 2.04; P=0.002) and functional independence (RR=1.83; 95% CI 1.08 to 3.08; P=0.024), and lower rates of mortality (RR=0.76; 95% CI 0.65 to 0.90; P=0.002) at 90-day follow-up compared with MEDT alone. However, EVT patients had higher rates of sICH (RR=7.48; 95% CI 2.27 to 24.61; P<0.001). CONCLUSIONS: EVT conferred significant patient benefit over MEDT alone in the treatment of PC-LVO. Future studies should better define patients for whom EVT is futile and determine factors that contribute to higher rates of sICH.