Cerebral Infarction Score Research Articles

Impact of workflow times on successful reperfusion after endovascular treatment in the late time window.

Successful and complete reperfusion should be the aim of every endovascular thrombectomy (EVT) procedure. However, the effect of time delays on successful reperfusion in late window stroke patients presenting 6-to-24h from onset has not been investigated. We pooled individual patient-level data from seven trials and registries for anterior circulation stroke patients treated with EVT between 6 and 24h from onset. We explored the impact of delays across multiple interval times, including onset to hospital arrival; hospital arrival to arterial puncture; imaging to arterial puncture; and onset to arterial puncture. Our primary outcome was successful reperfusion, defined as a modified thrombolysis in cerebral infarction (mTICI) score of 2b-3. Logistic regression analyses were performed to assess the association between each of the interval times and successful reperfusion. We included 608 patients. The median age was 70years (IQR 58-79), and 307 (50.5%) were females. Successful reperfusion was achieved in 494 (81.2%) patients. Patients with successful reperfusion had lower NIHSS scores (median 15 [IQR11-19] vs 17 [11-21], p = .02) and significantly shorter hospital arrival to arterial puncture time (90min [60-150] vs 110min [84.5-150], p = .01) than unsuccessful reperfusion. The odds of successful reperfusion decreased by 15% for every one-hour delay in arrival-to-puncture time (adjusted odds ratio 0.85, 95% CI: 0.75-0.95). Other workflow times did not impact the rate of successful reperfusion. Faster hospital arrival to arterial puncture time is associated with higher odds of successful reperfusion in late window stroke patients.

Evaluating the effect of noise reduction strategies in CT perfusion imaging for predicting infarct core with deep learning.

This study evaluates the efficacy of deep learning models in identifying infarct tissue on computed tomography perfusion (CTP) scans from patients with acute ischemic stroke due to large vessel occlusion, specifically addressing the potential influence of varying noise reduction techniques implemented by different vendors. We analyzed CTP scans from 60 patients who underwent mechanical thrombectomy achieving a modified thrombolysis in cerebral infarction (mTICI) score of 2c or 3, ensuring minimal changes in the infarct core between the initial CTP and follow-up MR imaging. Noise reduction techniques, including principal component analysis (PCA), wavelet, non-local means (NLM), and a no denoising approach, were employed to create hemodynamic parameter maps. Infarct regions identified on follow-up diffusion-weighted imaging (DWI) within 48hours were co-registered with initial CTP scans and refined with ADC maps to serve as ground truth for training a data-augmented U-Net model. The performance of this convolutional neural network (CNN) was assessed using Dice coefficients across different denoising methods and infarct sizes, visualized through box plots for each parameter map. Our findings show no significant differences in model accuracy between PCA and other denoising methods, with minimal variation in Dice scores across techniques. This study confirms that CNNs are adaptable and capable of handling diverse processing schemas, indicating their potential to streamline diagnostic processes and effectively manage CTP input data quality variations.

Effect of Proximal Blood Flow Arrest During Endovascular Thrombectomy (ProFATE): A Multicenter, Blinded-End Point, Randomized Clinical Trial.

The effect of temporary blood flow arrest during endovascular thrombectomy for acute ischemic stroke is uncertain due to the lack of evidence from randomized controlled trials. We aimed to investigate whether temporary blood flow arrest during endovascular thrombectomy using a balloon guide catheter improves intracranial vessel recanalization compared with nonflow arrest. The ProFATE trial (Proximal Blood Flow Arrest During Endovascular Thrombectomy) was a multicenter, randomized, participant- and outcome-blinded trial at 4 thrombectomy centers in the United Kingdom. Adults with acute ischemic stroke due to anterior circulation large vessel occlusion were randomly assigned (1:1) by a central, Web-based program with a minimization algorithm to undergo thrombectomy with temporary proximal blood flow arrest or nonflow arrest during each attempt. The primary outcome was the proportion of participants achieving near-complete/complete vessel recanalization (expanded Thrombolysis in Cerebral Infarction score of 2c or 3) at the end of the thrombectomy procedure, adjudicated by a blinded independent imaging core laboratory. Analyses were performed on the intention-to-treat population, adjusted for age, IV thrombolysis, onset-to-randomization time, Alberta Stroke Program Early CT Score, occlusion site, randomization site, and National Institutes of Health Stroke Scale. Between October 10, 2021, and June 27, 2023, we recruited 134 participants, of whom 131 participants (mean age, 75 years; 62 [47%] women and 69 [53%] men) were included in the final analysis. Sixty-six participants were allocated to the temporary blood flow arrest group and 65 to the nonflow arrest group. The proportion of participants with an expanded Thrombolysis in Cerebral Infarction 2c/3 score at the end of the endovascular procedure was 74.4% (49/66) in the flow arrest group and 70.8% (46/65) in the nonflow arrest group (adjusted odds ratio, 1.07 [95% CI, 0.45-2.55]; P=0.88). Among the prespecified secondary efficacy outcomes, a lower rate of emboli to a new vascular territory occurred in the blood flow arrest group compared with the nonflow arrest group (1.5% versus 12.3%; adjusted odds ratio, =0.04 [95% CI, 0.01-0.53]; P=0.014) and a higher rate of complete recanalization (expanded Thrombolysis in Cerebral Infarction score, 3) after the first attempt in the flow arrest group versus the nonflow arrest group (33.0% versus 15.3%; adjusted odds ratio, =3.80 [95% CI, 1.40-10.01]; P=0.007). No between-group differences were identified for the remaining procedural or clinical efficacy (modified Rankin Scale at 90 days) or safety outcomes (worsening of the stroke severity at 24 hours, adverse events, symptomatic intracranial hemorrhage, or mortality). Among patients presenting with anterior circulation large vessel occlusion acute ischemic stroke, temporary proximal blood flow arrest during endovascular thrombectomy, compared with nonflow arrest, did not significantly improve the near-complete/complete vessel recanalization (expanded Thrombolysis in Cerebral Infarction score, 2c-3) at the end of the procedure. Larger randomized controlled trials are warranted to confirm or refute a clinically significant treatment effect of temporary flow arrest on the functional outcome following endovascular thrombectomy. URL: https://www.clinicaltrials.gov; Unique identifier: NCT05020795.

Quality Improvement Intervention for Reducing Acute Treatment Times in Ischemic Stroke

Efficient care processes are crucial to minimize treatment delays and improve outcome after endovascular thrombectomy (EVT) in patients with ischemic stroke. A potential means to improve care processes is performance feedback. To evaluate the effect of performance feedback to hospitals on treatment times for EVT. This cluster randomized clinical trial was conducted from January 1, 2020, to June 30, 2022. Participants were consecutive adult patients with ischemic stroke who underwent EVT in 13 Dutch hospitals. No patients were excluded. Data analysis took place from March to May 2023. The intervention consisted of feedback on hospital performance using structure, process, and outcome indicators. Indicator scores were based on data from a national quality registry and compared with a benchmark. Performance feedback was provided through a dashboard for local quality improvement teams who developed and implemented improvement plans based on the feedback. Every 6 months, 3 to 4 randomly selected hospitals switched to the intervention condition. The primary outcome was time from door to groin puncture for all patients treated with EVT. Secondary outcomes included door-to-needle time, National Institutes of Health Stroke Scale (NIHSS) score at day 2, expanded Treatment in Cerebral Infarction (eTICI) score, and modified Rankin Scale (mRS) score at 3 months. The effect of the intervention was estimated with multivariable linear mixed models. A total of 4747 patients were included (intervention: 2431; control: 2316). Their mean (SD) age was 72 (13) years; 2337 (49.2%) were female and 2410 (50.8%) were male. The median (IQR) baseline NIHSS score was 14 (8-19). Median (IQR) door-to-groin puncture time under the intervention condition was 47 (25-71) minutes, compared with 52 (29-75) minutes under the control condition. The adjusted absolute reduction was 5 minutes (β = -4.8; 95% CI, -9.5 to -0.1; P = .04), corresponding to a relative reduction of 9.2% (95% CI, -18.3% to -0.2%). This study found that performance feedback provided through a dashboard used by local quality improvement teams reduced door-to-groin puncture time for EVT. Implementation of performance feedback in hospitals providing EVT can improve the quality of care for ischemic stroke. The Netherlands Trial Register: NL9090.

Effect of intravenous alteplase before endovascular thrombectomy on outcome after unsuccessful recanalization in the DIRECT-MT trial.

There are still some patients with acute anterior circulation large vessel occlusion stroke (LVOS) experienced unsuccessful recanalization after endovascular thrombectomy. The efficacy of intravenous alteplase before thrombectomy for such patients is unknown. We performed this study to investigate whether prior intravenous alteplase could affect the outcome of patients with unsuccessful recanalization. This is a post-hoc analysis of the DIRECT-MT trial. Patients with final extended thrombolysis in cerebral infarction (mTICI) score of 0-2a were included. Patients with successful recanalization (mTICI 2b-3) or could not be assessed for mTICI were excluded. The primary outcome was the 90-day modified Rankin scale (mRS) score, while secondary outcomes included 90-day functional independence (mRS 0-2), recanalization (modified arterial occlusive lesion) rates at 24-72h by CTA, infarction volume on CT, rates of symptomatic intracranial hemorrhage (SICH) and asymptomatic intracranial hemorrhage (aSICH). Among 656 randomized patients, 92 patients with unsuccessful recanalization were included, of which 55 patients underwent endovascular thrombectomy alone (EVT-group) and 37 patients underwent endovascular thrombectomy preceded by intravenous alteplase (combination group). No statistically significant difference in the 90-day mRS score was observed between the two groups (Adjusted cOR=1.65; 95%CI, 0.76 to 3.59). The volume of infarction, the proportion of 90-day functional independence, recanalization rates at 24-72 h, rates of SICH and rates of aSICH were similar in both groups. We found no evidence that prior intravenous alteplase could affect the clinical or imaging outcome in patients with acute anterior circulation LVOS and unsuccessful recanalization after endovascular thrombectomy.

Prolonged venous transit is associated with lower odds of excellent recovery after reperfusion in anterior large-vessel occlusion stroke.

Acute ischemic stroke due to anterior circulation large-vessel occlusion (AIS-LVO) remains a leading cause of disability despite successful reperfusion therapies. Prolonged venous transit (PVT) has emerged as a potential prognostic imaging biomarker in AIS-LVO. We aimed to investigate whether PVT is associated with a decreased likelihood of excellent functional outcome (modified Rankin Scale [mRS] score of 0-1 at 90 days) after successful reperfusion. In our prospectively collected, retrospectively reviewed database, we analyzed data from 104 patients with AIS-LVO who achieved successful reperfusion (modified Thrombolysis in Cerebral Infarction score of 2b/2c/3) between September 2017 and September 2022. PVT was defined as a time to maximum (Tmax) of ≥10 s in the superior sagittal sinus and/or torcula on computed tomography perfusion (CTP) imaging. Patients were categorized into PVT-positive (PVT+) and PVT-negative (PVT-) groups. The primary outcome was excellent functional recovery at 90 days. Of the 104 patients, 30 (29%) were PVT+. Excellent functional outcome was achieved in 38 patients (37%). PVT+ patients had a significantly lower rate of excellent recovery compared to PVT- patients (11% vs. 39%; p < 0.001). After adjusting for possible confounders, PVT positivity was independently associated with lower odds of excellent recovery (adjusted odds ratio 0.11, 95% confidence interval 0.02 to 0.48; p = 0.006). Among patients with AIS-LVO who achieved successful reperfusion, PVT positivity was independently associated with a decreased likelihood of excellent functional outcome at 90 days. Assessment of PVT on CTP may provide valuable prognostic information and aid in clinical decision making for patients with AIS-LVO.

Direct endovascular treatment may be more appropriate for patients with good collateral circulation: a retrospective case-control study.

Recent studies have shown that endovascular treatment (EVT) alone is noninferior to the combination of intravenous thrombolysis and EVT (IVT + EVT) in patients with acute ischemic stroke due to large-vessel occlusion (AIS-LVO) in the anterior cerebral circulation. However, some studies report conflicting results suggesting that the benefits of IVT may be limited to specific subgroups. Previous research has established a strong correlation between collateral status and prognosis in patients treated with IVT or EVT. The primary aim of this study was to investigate the impact of collateral status on clinical outcomes in patients receiving EVT alone or IVT + EVT. We retrospectively collected data from 238 consecutive patients who were diagnosed with AIS-LVO and underwent EVT or IVT + EVT from January 2019 to January 2023. Patients were divided into two groups, based on whether they received IVT prior to EVT. Multivariable ordinal logistic regression with an interaction term was used to assess the impact of collateral circulation on treatment outcomes, including 90-day modified Rankin Scale (mRS) scores, success rate of recanalization, incidence of intracerebral hemorrhage, mortality, embolus migration, and the rate of achieving a modified thrombolysis in cerebral infarction (mTICI) score of 3. To adjust the common odds ratio (OR), we included variables such as gender, age, baseline National Institutes of Health Stroke Scale (NIHSS) score, Alberta Stroke Program Early Computed Tomography Score (ASPECTS), and onset-to-puncture time. Overall, patients with adequate collateral circulation, defined as a regional leptomeningeal collateral score of 17-20 points, demonstrated more favorable 90-day outcomes, including lower mRS score, higher recanalization success rate, and lower rates of intracerebral hemorrhage, mortality, embolus migration, along with higher likelihood of achieving mTICI 3 score. However, the impact of collateral circulation differed between the two groups. In the EVT group, improved collateral circulation was significantly associated with better outcomes [OR: 8.381, 95% confidence interval (CI): 2.120-46.695, P=0.006]. In the IVT + EVT group, improved collateral circulation was linked to better outcomes (OR: 3.157, 95% CI: 1.618-6.541, P=0.001), it was additionally associated with a higher mortality rate (OR: 0.334, 95% CI: 0.145-0.725, P=0.007), increased incidence of embolus escape (OR: 0.359, 95% CI: 0.130-0.894, P=0.033), and a reduced likelihood of mTICI 3 recanalization (OR: 0.460, 95% CI: 0.244-0.844, P=0.014). Better collateral circulation is associated with favorable 90-day outcomes in both EVT group and IVT + EVT group. However, in the IVT + EVT group better collateral circulation was also linked to a higher rate of mortality, increased incidence of embolus escape, and lower rate of mTICI 3 recanalization. This may suggest that AIS-LVO patients with better collateral circulation could benefit more from EVT alone. Future studies are warranted to confirm these findings.

Endovascular thrombectomy for acute ischemic stroke with primary occlusion of the anterior cerebral artery: A meta-analysis.

Anterior cerebral artery (ACA) occlusions account for up to 4 % of all acute ischemic strokes and may lead to debilitating outcomes. While endovascular thrombectomy (EVT) is a well-established treatment for large vessel occlusions, its efficacy and safety for primary ACA occlusions remains unclear. This systematic review and meta-analysis aims to address this gap by evaluating the clinical outcomes, safety, and efficacy of EVT in the treatment for primary ACA occlusions. Following PRISMA guidelines, five databases were queried from database inception until April 2024 for studies describing the use of EVT for acute ischemic primary ACA occlusions. Following abstract, title, and full text-screening, data on patient demographics, clinical presentation, procedural details, and surgical outcomes were extracted from included articles. Primary outcomes were successful reperfusion (modified-Treatment in Cerebral Infarction (mTICI) score 2b-3), and favorable functional outcomes (3-month modified Rankin Scale (mRS) scores 0-2). Secondary outcomes included 3-month mortality rates and procedural complication rates. Meta-analysis was performed using a random-effects model, with heterogeneity assessed by the Higgins index (I²>50 %). Ten studies met eligibility criteria, encompassing a total of 265 patients with complete clinical and outcome data. Across the pooled meta-analysis, the rate of successful reperfusion (mTICI ≥ 2b) was 0.78 (95 % CI: 0.67-0.86) and the rate of 3-month mRS score 0-2 was 0.41 (95 % CI: 0.33-0.51). Pooled meta-analysis of secondary outcomes analysis revealed a 3-month mortality rate of 0.20 (95 % CI: 0.15-0.26), while the rate of symptomatic intracerebral hemorrhage was 0.04 (95 % CI: 0.02-0.08). Our findings demonstrate that while successful reperfusion can be achieved with low complication rates, primary ACA occlusions treated with EVT are associated with high morbidity and mortality.

Predictive value of thrombus enhancement sign for stroke subtype and recanalization in acute basilar-artery occlusion.

Thrombus enhancement sign (TES) is associated with cardioembolic stroke and first-pass angiographic failure in anterior ischemic stroke. However, the relationship between TES and stroke subtype and recanalization status after endovascular treatment (EVT) in basilar artery occlusion (BAO) remains unknown. This retrospective study included consecutive patients with acute BAO who underwent EVT between January 2020 and September 2023. Each patient underwent baseline non-contrast computed tomography (CT) and CT angiography. Two independent readers assessed the presence of TES. Stroke types were classified according to the Trial of ORG 10172 for Acute Stroke Treatment. Successful recanalization was defined as a modified Thrombolysis in Cerebral Infarction score of 2b-3 after EVT. Clinical and interventional parameters, along with histopathological thrombi examination results, were compared between the TES-positive and TES-negative groups. The associations between TES and stroke subtype and recanalization status were analyzed using univariate and multivariate analyses. A total of 151 patients were included in the analysis, among whom 116 (77%) exhibited TES. TES showed a significant correlation with cardioembolic and cryptogenic strokes (odds ratio [OR]: 8.56; 95% confidence interval: 3.49-22.4; p < 0.001), whereas the TES-positive thrombi were characterized by a higher fibrin/platelet proportion (p = 0.002) and lower erythrocyte proportion (p = 0.044). The TES-positive group demonstrated favorable outcomes compared to the TES-negative group, including a shorter procedure time (p < 0.001), lower number of thrombectomy attempts (p = 0.010), higher incidence of first pass success (p = 0.022), and lower rate of requiring rescue angioplasty and/or stenting (p < 0.001). In multivariate analysis, TES remained independently associated with successful recanalization (OR: 9.63; 95% CI: 2.33, 47.7; p = 0.003) after adjusting for baseline confounders. Visualization of TES serves as a reliable and easily accessible marker for identifying cardioembolic and cryptogenic strokes and predicting recanalization success in thrombectomy for basilar artery occlusion.

One in six patients exhibit changes in reperfusion on 10-minute repeat cerebral angiography during mechanical thrombectomy for stroke

BackgroundPost-recanalization target vessel re-occlusion (TVR) following endovascular thrombectomy (EVT) is a known complication of the procedure, and it is associated with worse long-term functional outcomes. The incidence and factors that...

Vessel deviation during stent retrieval predicts successful recanalization in stent-based mechanical thrombectomy for M2 occlusion.

This study aimed to clarify whether there is a relationship between vessel deviation during stent retrieval and successful recanalization in stent-based mechanical thrombectomy (MT) for M2 occlusion. The video of the MT was reviewed for each of the 25 included patients with M2 occlusion. The vertical distance of vessel deviation at the time of stent retrieval was defined as D, and the diameter of the balloon guide catheter shown on the same screen was defined as B. The D/B ratio was calculated as an index of the vessel deviation. The presence or absence of successful recanalization (thrombolysis in cerebral infarction (TICI) score of 2b/3) was compared based on the D/B ratio and clinical factors. Of the 25 patients, successful recanalization was achieved in 18 (72%). The median D/B ratio with successful recanalization was 0.9, which was significantly lower than that without successful recanalization (2.5, p < 0.001, Mann-Whitney U test). Combined aspiration catheters were used in 24 cases. In nine (36%) cases, the tip of the aspiration catheter was in M2 during stent retrieval. The median D/B ratio with the position of the aspiration catheter tip in M1 or the internal carotid artery was 1.5, which was significantly higher than that with the position in M2 (0, p = 0.003, Mann-Whitney U test). In stent-based MT for M2 occlusion, cases in which successful recanalization was achieved showed less vessel deviation during stent retrieval. To reduce vessel deviation, advancing the combined aspiration catheter up to M2 is useful.

Mechanical thrombectomy failure in anterior and posterior circulation stroke: current results from a high-volume comprehensive center.

Mechanical thrombectomy (MT) is an established therapy for acute ischemic stroke (AIS), but recanalization is not always achieved. Common reasons are inadequate removal at the thrombus site and difficulties with the access route. In order to identify risk factors for MT failure we conducted a retrospective study on a high-volume comprehensive stroke center. Evaluation of 552 thrombectomies (2019-23; anterior and posterior circulation, direct aspiration +/- stent retriever [SR]). MT failures (= modified Thrombolysis in Cerebral Infarction score 0 or 1) were analyzed for age, sex, pre- and post-MT modified Rankin Scale, bridging intravenous thrombolysis (IVT), occlusion site (anterior / posterior circulation, proximal / distal), the Kaesmacher classification and time trend results. MT failure occurred in 56 patients (10.1%; median age 76; 53.6% female). Nineteen (33.9%) patients received IVT (p = 0.326). Logistic regression analysis did not show a significant association of age, sex or occlusion site with MT failure (p = 0.165, p = 0.738, p = 0.838). Distal MT generally demonstrated lower success rates (p < 0.01). According to the Kaesmacher classification SR failure was the most frequent cause of MT failure (category 2B: 48%, p < 0.001). Time trend analysis suggests improving recanalization rates in the further course (4 times in year-on-year comparison; p < 0.01). MT failure occurs in AIS treatment, even in high-volume centers and occurs more frequently in distal occlusions. Improvements in device technology, particularly SR, and ongoing refinements in access route selection offer the prospect of better outcomes in the future.

Outcomes of Adjunct Emergent Stenting Versus Mechanical Thrombectomy Alone: The RESCUE-ICAS Registry.

Underlying intracranial stenosis is the most common cause of failed mechanical thrombectomy in acute ischemic stroke patients with large vessel occlusion. Adjunct emergent stenting is sometimes performed to improve or maintain reperfusion, despite limited data regarding its safety or efficacy. We conducted a prospective multicenter observational international cohort study. Patients were enrolled between January 2022 and December 2023 at 25 thrombectomy capable centers in North America, Europe, and Asia. Consecutive patients treated with mechanical thrombectomy were included if they were identified as having underlying intracranial stenosis, defined as 50-99% residual stenosis of the target vessel or intra-procedural re-occlusion. The primary outcome was functional independence, defined as modified Rankin Scale of 0-2 at 90 days. After applying inverse probability of treatment weighting (IPTW) based on propensity scores, we compared outcomes among patients who underwent adjunct emergent intracranial stenting (stenting) versus those who received mechanical thrombectomy alone. A total of 417 patients were included; 218 patients treated with mechanical thrombectomy alone (168 anterior circulation) and 199 with mechanical thrombectomy plus stenting (144 anterior circulation). Patients in the stenting group were less likely to be non-Hispanic White (51.8% vs 62.4%, p=0.03), and less likely to have diabetes (33.2% vs 43.1%, p=0.037) or hyperlipidemia (43.2% vs 56%, p= 0.009). In addition, there was a lower rate of IV thrombolysis use in the stenting group (18.6% vs 27.5%, p=0.03). There was a higher rate of successful reperfusion (modified Treatment In Cerebral Infarction score ≥ 2B) in the stenting versus mechanical thrombectomy alone group (90.9% vs 77.9%, p<0.001) and a higher rate of a 24-hour infarct volume of <30 mL (n=260, 67.9% vs 50.3%, p=0.005). The overall complication rate was higher in the stenting group (12.6% vs 5%, p=0.006), but there was not a significant difference in the rate of symptomatic hemorrhage (9% vs 5.5%, p=0.162). Functional independence at 90 days was significantly higher in the stenting group (42.2% vs. 28.4%, adjusted odds ratio 2.67; 95% CI, 1.66-4.32). In patients with underlying stenosis who achieved reperfusion with mechanical thrombectomy, adjunct emergent stenting was associated with better functional outcome without a significantly increased risk of symptomatic hemorrhage. https://clinicaltrials.gov/study/NCT05403593.

Predictors of futile recanalization in ischemic stroke patients with low baseline NIHSS.

There is yet no randomized controlled evidence that mechanical thrombectomy (MT) is superior to best medical treatment in patients with large vessel occlusion but minor stroke symptoms (National Institutes of Health Stroke Scale (NIHSS) <6). Prior studies of patients with admission NIHSS scores ≥6 observed unfavorable functional outcomes despite successful recanalization, commonly termed as futile recanalization (FR), in up to 50% of cases. The aim of this study is to determine the prevalence of FR in patients with minor stroke and identify associated patient-specific risk factors. Our multicenter cohort study screened all patients prospectively enrolled in the German Stroke Registry Endovascular Treatment from 2015 to 2021 (n = 13,082). Included were patients who underwent MT for anterior circulation vessel occlusion with a baseline NIHSS score of <6 and successful recanalization (modified Thrombolysis in Cerebral Infarction (mTICI) scores of 2b-3). FR was defined by modified Rankin Scale (mRS) scores of 2-6 at 90 days. Multivariable logistic regression analysis was conducted to explore factors associated with FR. A total of 674 patients met the inclusion criteria. FR occurred in 268 (40%) patients. Multivariable logistic regression analysis indicates that higher age (adjusted odds ratio (aOR) = 1.04 (95% confidence interval (CI) = 1.02-1.06)), pre-stroke mRS 1 (aOR = 2.70 (95% CI = 1.51-4.84)), transfer from admission hospital to comprehensive stroke center (aOR = 1.67 (95% CI = 1.08-2.56)), longer time from symptom onset/last seen well to admission (aOR = 1.02 (95% CI = 1.00-1.04)), MT under general anesthesia (aOR = 1.78 (95% CI = 1.13-2.82)), higher NIHSS after 24 h (aOR = 1.09 (95% CI = 1.05-1.14)), and symptomatic intracranial hemorrhage (aOR = 16.88 (95% CI = 2.03-140.14)) increased the odds of FR. There was no significant difference in primary outcome between achieving mTICI score of 2b or 3. Unfavorable functional outcomes despite successful vessel recanalization were frequent in acute ischemic stroke patients with low NIHSS scores on admission. We provide patient-specific risk factors that indicate an increased risk of FR and should be considered when treating patients with minor stroke. The data that support the findings of our study are available on reasonable request after approval of the German Stroke Registry (GSR) steering committee.

Outcomes of endovascular thrombectomy for acute ischaemic stroke in patients aged ≥80 years: A Hong Kong stroke center experience

BackgroundElderly patients contribute to the large proportion of ischaemic stroke worldwide. Currently, treatment for elderly stroke remains aggressive, as the exact age cutoff for endovascular thrombectomy (EVT) has not been well established due to a lack of large-scale randomized control trials. In this study we investigate the difference in outcome after EVT in the octogenarian and above, compared to their younger counterparts. MethodsEVT patients were divided into two groups, the octogenarian group and younger group (below age of 80). Primary outcome were the 90-days post-thrombectomy functional independence (modified Rankin scale), and Barthel index. Secondary and safety outcomes of post-thrombectomy were also analyzed, including reperfusion status (modified Thrombolysis in Cerebral Infarction (TICI) score), National Institutes of Health Stroke Scale (NIHSS), major complications and mortality rate. ResultsA total 340 patients were included from 2020 to 29 Feb 2024, and patients’ demographics were obtained. Poorer neurological outcome and functional independence were noted in octogenarian group compared with younger counterpart (OR 0.33; 95 % CI 0.14-0.51; p < 0.001). A slightly higher trend of overall post-procedural death was also identified in elder group compared with the younger group (OR 1.48; 95 % CI 0.85-2.60, p = 0.08). Subgroup analysis with more advanced age cutoff at 90 took a step further and proposed that advanced age resulting in more devastating neurological outcome. ConclusionOutcomes after endovascular thrombectomy in the elder group were significantly worse than their younger counterparts. More than 80 % of elder group who were treated with EVT required moderate functional dependence, and one in four were dead within 90-days post-EVT.

Economic and Efficient: Introducing the Bifurcation-Invisible Sign in Endovascular Thrombectomy for Middle Cerebral Artery Occlusions

Introduction: Selecting thrombectomy techniques for acute ischemic stroke due to large vessel occlusion significantly affects outcomes and costs. This study introduces the Bifurcation-Invisible (BI) sign identified on initial microcatheter angiogram in acute middle cerebral artery occlusions before endovascular thrombectomy. We aimed to evaluate whether this sign is associated with better angiographic outcomes using contact aspiration (CA) versus stent retriever (SR). Methods: In this study, we reviewed 285 cases of acute M1-segment middle cerebral artery (M1-MCA) occlusions treated with SR or CA. Angiographic success was evaluated using modified Thrombolysis In Cerebral Infarction (mTICI) scores after the first attempt, clinical outcomes by 90-day modified Rankin Scale (mRS) scores, and procedural costs were analyzed. Categorical variables were analyzed using χ2 or Fisher’s exact test, and continuous variables using Student’s t test or Mann-Whitney U test. Subgroup multivariate logistic analysis and interaction tests were conducted, with post hoc analysis applying Bonferroni correction. Results: BI-positive patients treated with CA had higher first-pass reperfusion rates (mTICI 2b-3: 64.0% vs. 41.3%, p = 0.005; Bonferroni-corrected p = 0.030) and 19.8% lower device costs (p < 0.05) than those treated with SR. BI-positive CA patients had higher first-pass reperfusion rates (mTICI 2b-3: 64.0% vs. 32.1%; p < 0.001; Bonferroni-corrected p = 0.002) and a 39.9% reduction in device costs (p < 0.05) than BI-negative patients. The interaction tests showed significant interactions between the presence of BI and CA for first-pass reperfusion rates (p = 0.007) and device costs (p < 0.001). Conclusion: The BI sign, a refined version of the branching-site occlusion sign identified via microcatheter angiography, could guide the selection of CA, improving recanalization rates and reducing costs in MCA occlusions.

Abstract 028: Intraoperative Time‐Resolved Spectroscopy During Mechanical Thrombectomy Can Predict the Extent of Infarct

Introduction The Thrombolysis in Cerebral Infarction (TICI) score is a predictor ofclinical outcomes following thrombectomy. However, leptomeningeal collateral circulation inlarge vessel occlusion (LVO) also influences the infarct size on postoperative magnetic resonanceimaging (MRI). Near‐infrared spectroscopy (NIRS) offers potential for evaluating collateralmicrocirculation in LVO patients. Time‐resolved spectroscopy (TRS), an advanced NIRStechnology, provides absolute optical properties with greater spatial resolution and deeperpenetration compared to conventional NIRS. This study compares intraoperative TRSmeasurements with infarct size observed on post‐thrombectomy MRI. Methods Nine patients with acute ischemic stroke underwent endovascular therapy (EVT) for LVO involving the superior division of the middle cerebral artery (MCA). Intraoperative TRSmeasurements, including oxy‐/deoxy‐/total‐hemoglobin (HbO2, HHb, HbTot) and oxygensaturation (StO2), were taken in the MCA superior division territory on affected and unaffectedsides. Post‐thrombectomy reperfusion was assessed using TICI score. MRI was performed toevaluate stroke extent following thrombectomy. Recanalization was marked when the guidingcatheter was withdrawn from the internal carotid artery and full reperfusion was restored.Hemodynamic parameters, medications, and relevant interventions were recorded and time‐lockedwith corresponding TRS data.Patients were assigned to 2 groups based on postoperative MRI findings. Group 1 had a corticalinfarct in the TRS detection region. Group 2 had no infarct in the TRS detection region. To evaluate immediate changes in cerebral perfusion on the affected side, we conducted the Wilcoxon signed‐rank test to compare average 5‐minute TRS values before and afterrecanalization. Using said averages, we performed Welch's t test to assess the difference in the HbO2/HHb ratio pre‐ vs post‐recanalization between patients with and without cortical infarct inthe TRS detection region. Results Successful reperfusion (TICI 2b/3) was achieved in all patients. On the affected side, differences between average pre‐ and post‐recanalization HbO2, HbTot, and StO2 werestatistically significant (p‐value: 0.0078, 0.0078, 0.0156, respectively). In contrast, differenceswere not statistically significant on the unaffected side. These findings align with reperfusionoutcomes graded by TICI scores. Additionally, there was a statistically significant difference inthe HbO2/HHb ratio pre‐ vs post‐recanalization between patients with and without infarct (p‐value: 0.0208, 95% CI: ‐0.5514 ‐ 0.06268). Moreover, larger difference in the HbO2/HHb ratiocorrelates with a higher likelihood of developing post‐thrombectomy cortical infarct, regardless of TICI scores. This difference may be due to a perfusion‐metabolism mismatch during reperfusion, which may be strongly associated with the extent of brain tissue infarction, particularly in patients with limited or absent collateral circulation. Patients without substantial cortical stroke onpostoperative MRI had relatively stable TRS readings on both sides throughout the procedure, likely reflecting robust collateral circulation. Conclusions These results suggest that TRS can be used as a non‐invasive tool to monitorchanges in cerebral microvascular perfusion during EVT, including quantifying reperfusionoutcomes and evaluating the extent of collateral circulation. Additionally, TRS may play a crucialrole in assessing brain tissue viability and guiding post‐EVT clinical decision‐making. Validationof these findings requires a larger cohort and further consideration of patient‐specific factors.(Funding: HP‐5568330; Akbari/Milner).

Abstract 046: Intracranial Stenting After Successful Recanalization in Patients with Intracranial Atherosclerosis Improves Outcomes ‐ RESCUE‐ICAS Secondary Analysis

Introduction Intracranial atherosclerosis (ICAS) is estimated to cause 10‐15% of large‐vessel occlusions (LVOs) in stroke. The prospective Registry of Emergent Large Vessel Occlusion Due to Intracranial Stenosis (RESCUE‐ICAS) demonstrated better outcomes in patients undergoing adjuvant acute stenting of the underlying ICAS plaque than in those who underwent endovascular thrombectomy (EVT) alone. We present a secondary analysis of RESCUE‐ICAS in which we evaluated the safety and radiographic and clinical outcomes of acute stenting in patients with ICAS‐LVO who had successful recanalization ( modified treatment in cerebral infarction ( mTICI) score≥2B). Methods RESCUE‐ICAS was an international, multicenter, observational, prospective cohort study of 417 consecutive adult patients who underwent EVT secondary to ICAS‐LVO, as defined by 50‐99% stenosis or reocclusion after EVT. Patients who experienced successful recanalization (mTICI≥2B) at the end of thrombectomy and prior to stenting (in the stenting group) were included in this secondary analysis. Our primary endpoints were modified Rankin Scale (mRS) score at 90 days and 24‐hour infarct volume on MRI. Safety endpoints included symptomatic intracranial hemorrhage and death at 90 days. Subanalysis of all patients who experienced mTICI≥2B after initial EVT alone prior to stenting was used to determine the impact of acute stenting on this cohort. Results A total of 351 (84.2%) patients in the total cohort had mTICI≥2B at the end of the procedure. Stenting was performed in 181 (51.6%) of these patients. The odds of functional independence at 90 days with mRS 0‐2 was higher for those who acutely underwent stenting (adjusted odds ratio 1.88 [95% CI 1.09‐3.26]; p=0.024). Patients who underwent stenting were more likely to have 24‐hour MRI infarct volume &lt;30 mL than those who underwent EVT alone (n=131, 70.1% vs 54.8%, p=0.022; adjusted odds ratio (aOR) 3.21 [95% confidence interval (CI) 1.46‐7.07]; p=0.004). In our subanalysis, patients with mTICI≥2B who underwent acute intracranial stenting experienced a higher odds of mRS 0‐2 at 90 days (aOR 2.19 [95% CI 1.01‐4.74]; p=0.046) and 24‐hour MRI infarct volume &lt;30 mL (aOR 3.27 [95% CI 1.047‐10.19]; p=0.042). There was no significant difference between the stenting and EVT alone groups in symptomatic intracranial hemorrhage (n=22, 7.2% vs 5.3%, p=0.466) or death at 90 days (n=85, 22.7% vs 25.9%, p=0.480). Conclusions Patients with ICAS‐LVO who had successful recanalization (mTICI≥2B) at the end of the procedure and underwent stenting had lower mean infarct volumes on 24‐hour MRI and better mean mRS at 90 days than those who had successful recanalization without stent placement. Further analysis also demonstrated that those who had mTICI≥2B after EVT alone who then underwent acute stent placement still had lower infarct volumes on 24‐hour MRI and improved mRS at 90 days when than those who did not undergo stenting after successful recanalization. Our analysis suggests that acute stent placement in patients experiencing successful recanalization leads to better clinical and radiographic outcomes, without increased risk of morbidity and mortality.

Abstract 053: The Red 43 Intermediate Catheter For Aspiration Thrombectomy Of Distal Medium Vessel Occlusions (DMVOs): A Multicenter Experience.

Introduction Recent clinical research has increasingly supported the effectiveness and safety of mechanical thrombectomy (MT) for treating occlusions in distal medium‐sized vessels. This underscores the necessity for specialized MT devices capable of navigating the tortuous anatomy of distal cerebrovascular vessels. The recently introduced RED 43 aspiration catheter can be used as a primary catheter for distal aspiration in acute ischemic stroke. In this multicenter study, we share our collective experience using the RED 43 catheter as the primary aspiration device for thrombectomy of DMVOs. Methods We identified consecutive patients with DMVOs who underwent primary aspiration thrombectomy using the RED 43 catheter from four high‐volume comprehensive stroke centers. We collected baseline clinical data, angiographic and clinical outcomes, as well as procedural complications. Cases with large vessel occlusion that were treated according to the standard of care and subsequently developed a DMVO were labeled as secondary DMVOs. The primary outcomes were the rate of first pass effect (FPE), defined as a modified Thrombolysis in Cerebral Infarction (mTICI) score of 2c or 3 on the first pass, and the rates of successful recanalization, defined as mTICI ≥2b at the end of the procedure. We also obtained rates of good functional outcomes, symptomatic intracerebral hemorrhage (ICH), asymptomatic ICH, subarachnoid hemorrhage (SAH), and in‐hospital mortality. Results We identified 102 consecutive cases of DMVOs undergoing primary aspiration thrombectomy using the RED 43 catheter. The mean age was 70 (SD: 14) years. The medianNIHSS score was 9 (IQR 6‐14), and the median ASPECTS was 9 (IQR 8‐10). Among these, 79 cases were primary DMVOs, and 23 were secondary DMVOs. The primary occlusion locations where the RED 43 catheter was used were as follows: distal M2 MCA segment in 41 cases (40.2%), M3 MCA segment in 29 cases (28.4%), M4 MCA segment in 5 cases (4.9%), A1 ACA in 4 cases (3.9%), A2/A3 ACA in 12 cases (11.8%), and P1 PCA in 8 cases (7.8%). The rate of first pass effect (FPE) (mTICI 2c or 3 on the first pass) using the RED 43 aspiration catheter was 57% (45/79) for primary DMVOs and 61% (14/23) for secondary DMVOs. The rate of successful recanalization (mTICI ≥2b at the end of the procedure) was 83% (66/79) for primary DMVOs and 87% (20/23) for secondary DMVOs. A good functional outcome (mRS 0‐2 at 3 months) was observed in 57% of patients. One patient experienced symptomatic ICH, and two patients died during hospitalization. Asymptomatic ICH and asymptomatic SAH were observed in 5 patients (4.9%) and 7 patients (6.9%), respectively. Conclusion Our study demonstrates the safety and efficacy of the RED 43 catheter for aspiration thrombectomy of both primary and secondary DMVOs, with good rates of FPE and successful recanalization, and an excellent safety profile.

Data-Driven Prognostication in Distal Medium Vessel Occlusions Using Explainable Machine Learning.

Distal medium vessel occlusions (DMVOs) are estimated to cause acute ischemic stroke (AIS) in 25-40% of cases. Prognostic models can inform patient counseling and research by enabling outcome predictions. However, models designed specifically for DMVOs are lacking. This retrospective study developed a machine learning model to predict 90-day unfavorable outcome [defined as a modified Rankin Scale (mRS) score of 3-6] in 164 primary DMVO patients. A model developed with the TabPFN algorithm utilized selected clinical, laboratory, imaging, and treatment data with the Least Absolute Shrinkage and Selection Operator feature selection. Performance was evaluated via 5-repeat 5-fold cross-validation. Model discrimination and calibration were evaluated. SHapley Additive Explanations (SHAP) identified influential features. A web application deployed the model for individualized predictions. The model achieved an area under the receiver operating characteristic curve of 0.815 (95% CI: 0.79-0.841) for predicting unfavorable outcome, demonstrating good discrimination, and a Brier score of 0.19 (95% CI: 0.177-0.202), demonstrating good calibration. SHAP analysis ranked admission National Institutes of Health Stroke Scale (NIHSS) score, premorbid mRS, type of thrombectomy, modified thrombolysis in cerebral infarction score, and history of malignancy as top predictors. The web application enables individualized prognostication. Our machine learning model demonstrated good discrimination and calibration for predicting 90-day unfavorable outcomes in primary DMVO strokes. This study demonstrates the potential for personalized prognostic counseling and research to support precision medicine in stroke care and recovery. DMVO = Distal medium vessel occlusion; AIS = acute ischemic stroke; mRS = modified Rankin Scale; SHAP = SHapley Additive Explanations; NIHSS = National Institutes of Health Stroke Scale; ST = stroke thrombectomy; TRIPOD = Transparent Reporting of Multivariable Prediction Models for Individual Prognosis or Diagnosis; CT = computed tomography; CTP = CT perfusion; MRI = magnetic resonance imaging; CTA = CT angiography; DVT = deep vein thrombosis; PE = pulmonary emboli; TIA = transient ischemic attack; BMI = body mass index; ALP = alkaline phosphatase; ALT = alanine transaminase; AST = aspartate aminotransferase; NCCT-ASPECTS = Alberta Stroke Program Early CT Score; IVT = intravenous thrombolysis; mTICI = modified thrombolysis in cerebral infarction; ER = emergency room; kNN = k-nearest neighbor; LASSO = Least Absolute Shrinkage and Selection Operator; PDPs = partial dependence plots; ROC = receiver operating characteristic; PRC = precision-recall curve; AUROC = area under the ROC curve; AUPRC = area under the PRC; CI = confidence interval.