Posterior Circulation Occlusions Research Articles

The use of a (non-) balloon guide catheter in endovascular stroke treatment, a registry of real-life use and nationwide questionnaire

IntroductionDespite literature suggesting benefits of a balloon guide catheter (BGC) in stroke thrombectomy, BGCs are not routinely used. This study aimed to get insights in the use of a BGC and the reasons (not) to inflate the balloon. MethodsData were used of the Maastricht Stroke Quality Registry (MaSQ-Registry), a prospective registry for quality purposes of stroke patients treated between September 2020-February 2023. Additionally, a Dutch nationwide questionnaire was sent among all stroke treating physicians of the Dutch Society of Interventional Radiology (NVIR). Information on the use and reasons for selecting a (non-)BGC and using the BGC was collected. ResultsOut of 511 patients registered in the MaSQ-Registry, 458 were included. In 69% (n=317) of the patients a BGC was used; in 68% (n=214) the balloon was not inflated. In 95% of the posterior circulation occlusions a non-BGC was used.In total 47 treating physicians from sixteen stroke centers responded to the questionnaire. 51% (n=24) preferred a non-BGC and 30% (n=14) never used a BGC. 52% and 18% of the BGC-users estimated they inflate the balloon in 80-100% and 0-20% of the times, respectively. The main reasons reported for not inflating the balloon were when the BGC was occlusive (47%) or not placeable (34%) in the carotid artery. ConclusionThis study shows variation in the use of (non-)BGC use with and without inflated balloon among treating physicians in the Netherlands, highlighting current limited consensus regarding the use of (non-)BGCs among stroke treating physicians.

Quantitative Analysis of Occipital Artery Bypass Donor Vessels by Ultrasonography and DSA.

Occipital artery (OA) acts as a vital donor vessel in intra-cranialand extra-cranial bypass. Ultrasonography and digital subtracted angiography (DSA) are becoming increasingly important in the assessment of vascular morphology and hemodynamically; however, quantitative analysis of occipital artery bypass donor vessels by Ultrasonography and DSA are seldom discussed. A retrospective study involving 62 cases accepted occipital artery bypass to treat posterior circulation aneurysms or artery occlusion/stenosis. The characteristics of OA are collected and analyzed. Occipital artery bypasses were performed to treat posterior circulation aneurysms in 34 patients and to treat posterior circulation artery occlusion or stenosis in 28 patients. Compared with the ultrasonography group, the DSA group had a greater diameter of OA, and Bland Altman analysis indicated that the discrepancy between the 2 groups was about 0.555 mm. Ultrasonography showed the characteristics of OA: the mean Peak Systolic Velocity (PSV) was 42.98 cm/s, the mean End Diastolic Velocity (EDV) was 8.811 cm/s, and the mean Resistance Index (RI) was 1.46. There were no statistical differences in the diameter of OA, PSV, EDV, and RI between the male group and female group, the elderly group and younger adult group or the left occipital artery group and right occipital artery group. However, compared with patients with posterior circulation aneurysms, patients with artery occlusion or stenosis were older and had higher PSV, RI, and greater diameter in occipital arteries. The mean diameter of occipital arteries was increased in the first postoperative years but reduced in 3 patients during 1 year follow-up. Both ultrasonography and DSA were effective assessment methods of occipital artery bypasses, and the DSA group had a greater diameter of OA. Age, gender, and left or right sides had little effect on the diameter of OA, PSV, EDV, and RI. Posterior circulation occlusion or stenosis had higher PSV, RI, and greater diameter of the occipital artery when compared with posterior circulation aneurysms. Occipital artery bypasses could increase the diameter of OA in most cases.

Abstract TP132: Optimal CT Perfusion Post-Processing Method in Posterior Circulation Stroke

Objective: CT-perfusion (CTP) has revolutionised stroke care by improving diagnostic accuracy and expanding eligibility to acute therapies. Software packages utilise various mathematical techniques to transform raw perfusion data into measures of infarct core and ischaemic penumbra. These techniques have been derived from studies of anterior-circulation stroke and not yet validated in posterior circulation stroke (PCS). We examined the optimal CTP thresholds for acute PCS. Methods: Data were analysed from 331-patients diagnosed with a PCS enrolled in the International-stroke-perfusion-registry (INSPIRE). Twenty-seven-patients with baseline multimodal-CT with occlusion of a large posterior-circulation (PC) artery and follow up diffusion-weighted-MRI at 24-48 hours were included. CTP parametric maps were generated using five different post-processing methods. Receiver-operating-curve analysis was used to determine the optimal perfusion parameter and thresholds. Results: Partial deconvolution was the optimal post-processing method for characterisation of ischaemic penumbra and infarct core. Mean transit time (MTT) at a threshold of >165% and >195% most accurately defined ischaemic core (AUC=0.73) and penumbra (AUC=0.78) respectively. Post-processing technique influenced accuracy of core (AUC range=0.54-0.73) and penumbra (AUC range=0.72-0.79) estimates. MTT was consistently the most accurate parameter at distinguishing core and penumbra across all post-processing methods. Conclusion: CTP has significant diagnostic utility in PCS. Accuracy of CTP varies considerably by post-processing method. The underlying post-processing technique employed by individual software packages should be considered when interpreting the accuracy of ischemic core and penumbra estimates.

Abstract WP302: Different Clot Characteristics According to the Clot Volume: A Microscopic Analysis of Clot Composition

Background and Objectives: Understanding the mechanisms of thrombosis is crucial for the future advancement in treating ischemic stroke. While many researches on thrombogenesis have been conducted, there was a limited data on thrombus growth. In this study, we investigated whether the clot composition or clot characteristics differed by the clot size using microscopic analysis of ischemic clot. Methods: We obtained the clots from 238 ischemic stroke patients who received endovascular treatment between July 2017 and July 2023 at Severance Stroke Center. We quantitatively analysed the clot components identified using immunohistochemistry. The fractions of each component such as fibrin, red blood cells (RBC), and platelets were calculated as the percentage pixel density of the total clot area. Clot volume was semiautomatically measured on thin-section computed tomography performed at stroke presentation using software. We determined the association between clot volume and histopathologic composition, arrangement patterns, and clinical or radiological features. Results: Among the 238 patients, the median (interquartile) of clot volume was 47.0 mm 3 (range 23.8-79.8). As the clot volume increased, the proportion of RBC became larger (r = 0.307. P <0.001) and the proportion of platelet became smaller (r = -0.150, p=0.029). In terms of RBC patterns, purely aggregated RBC patterns, rather than RBC-fibrin mixture patterns, was positively associated with the clot volume. After adjusting for potential confounders including posterior circulation occlusion, serum hemoglobin levels, serum albumin levels, and the presence of active cancer (all p<0.05 in univariable analysis), clot volume was independently related with the proportion of RBC (ß 0.726, SE 0.302, p =0.017) or the presence of purely aggregated RBC pattern (ß 59.182, SE 11.684, p <0.001). Conclusions: As the clot volume increased, the proportion of RBCs increases, and areas of purely packed with RBCs become larger. These findings suggest that as the clot grows, RBC mainly involved the clot volume growth.

Intravenous Thrombolysis Before Endovascular Treatment in Posterior Circulation Occlusions: A MR CLEAN Registry Study.

The effectiveness of intravenous thrombolysis (IVT) before endovascular treatment (EVT) has been investigated in randomized trials and meta-analyses. These studies mainly concerned anterior circulation occlusions. We aimed to investigate clinical, technical, and safety outcomes of IVT before EVT in posterior circulation occlusions in a nationwide registry. Patients were included from the MR CLEAN Registry (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands), a nationwide, prospective, multicenter registry of patients with acute ischemic stroke due to a large intracranial vessel occlusion receiving EVT between 2014 and 2019. All patients with a posterior circulation occlusion were included. Primary outcome was a shift toward better functional outcome on the modified Rankin Scale at 90 days. Secondary outcomes were favorable functional outcome (modified Rankin Scale scores, 0-3), occurrence of symptomatic intracranial hemorrhages, successful reperfusion (extended Thrombolysis in Cerebral Ischemia ≥2B), first-attempt successful reperfusion, and mortality at 90 days. Regression analyses with adjustments based on univariable analyses and literature were applied. A total of 248 patients were included, who received either IVT (n=125) or no IVT (n=123) before EVT. Results show no differences in a shift on the modified Rankin Scale (adjusted common odds ratio, 1.04 [95% CI, 0.61-1.76]). Although symptomatic intracranial hemorrhages occurred more often in the IVT group (4.8% versus 2.4%), regression analysis did not show a significant difference (adjusted odds ratio, 1.65 [95% CI, 0.33-8.35]). Successful reperfusion, favorable functional outcome, first-attempt successful reperfusion, and mortality did not differ between patients treated with and without IVT. We found no significant differences in clinical, technical, and safety outcomes between patients with a large vessel occlusion in the posterior circulation treated with or without IVT before EVT. Our results are in line with the literature on the anterior circulation.

Evaluation of CINA® LVO artificial intelligence software for detection of large vessel occlusion in brain CT angiography

ObjectiveTo systematically evaluate the ability of the CINA® LVO software to detect large vessel occlusions eligible for mechanical thrombectomy on CTA using conventional neuroradiological assessment as gold standard. MethodsRetrospectively, two hundred consecutive patients referred for a brain CTA and two hundred patients that had been subject for endovascular thrombectomy, with an accessible preceding CTA, were assessed for large vessel occlusions (LVO) using the CINA® LVO software. The patients were sub-grouped by occlusion site. The original radiology report was used as ground truth and cases with disagreement were reassessed. Two-by-two tables were created and measures for LVO detection were calculated. ResultsA total of four-hundred patients were included; 221 LVOs were present in 215 patients (54 %). The overall specificity was high for LVOs in the anterior circulation (93 %). The overall sensitivity for LVOs in the anterior circulation was 54 % with the highest sensitivity for the M1 segment of the middle cerebral artery (87 %) and T-type internal carotid occlusions (84 %). The sensitivity was low for occlusions in the M2 segment of the middle cerebral artery (13 % and 0 % for proximal and distal M2 occlusions respectively) and in posterior circulation occlusions (0 %, not included in the intended use of the software). ConclusionsLVO detection sensitivity for the CINA® LVO software differs largely depending on the location of the occlusion, with low sensitivity for detection of some LVOs potentially eligible for mechanical thrombectomy. Further development of the software to increase sensitivity to all LVO locations would increase the clinical usefulness.

Abstract 054: Transradial Thrombectomy Using "Sheathless PV" Guide Catheter in Armenia: Three‐Year Institutional Experience in 103 Cases

Introduction Transradial access (TRA) in neuroendovascular procedures has gained popularity in recent years (1). It offers numerous advantages and stimulated development of long flexible large lumen guiding catheters as well as adoption of existing cost‐efficient alternatives used in cardiac and peripheral interventions (2,3). We report our three‐year experience using the Sheathless PV guide catheter (Asahi Intecc, Japan) in a consecutive series of acute stroke patients undergoing endovascular thrombectomy (ET) at a Comprehensive Stroke Center in Yerevan, Armenia. The interest in its use specifically for TRA stemmed from competitive price (∼ $100 per catheter vs ), hydrophilic coating of the outer shaft, as well as lack of femoral closure devices in the country. Methods We retrospectively identified all consecutive acute stroke patients who had undergone ET via TRA from a prospectively maintained institutional stroke database between June 2020 and June 2023. Data were collected on determinants of decision to proceed with TRA‐first approach, baseline patient imaging and clinical characteristics, location of the occlusion, puncture‐to‐reperfusion time (PT‐RT), conversion to transfemoral access (TFA), periprocedural complications, and procedural/clinical outcomes. Results were compared to patients who underwent TFA‐first ET over the same time period. The Mann‐Whitney U‐test was used to analyze the continuous variables and chi‐square test was used for categorical variables. Standardized TRA technique involved exchanging the puncture needle to a short 6Fr introducer first, then over a J‐wire, to a 90cm (0.090" ID/0.110" OD) Sheathless PV guide catheter over a dilator. The dilator was then removed, and a long JR4 diagnostic catheter was used to select cervical vessels over a 0.035 wire and advance the guide over in a triaxial fashion. Results A total of 538 patients underwent ET during the analyzed 3‐year period, of which access was either not recorded, or was other than TRA/TFA in 23 patients (excluded from analysis). Of the remaining 515 patients, 103 had TRA‐first (all using Sheathless PV guide catheter) and 412 had TFA‐first (various guide catheters). The decision to proceed with TRA was at the discretion of the operator and was influenced by presence of bovine arch on CTA (for left anterior occlusions), favorable angle between the right subclavian and the right common carotid arteries (for right anterior occlusions), dominant right vertebral artery or favorable angle of V1 origin (for posterior circulation occlusions). Of 103 TRA cases, 71 (68.9%) were in the right carotid circulation, 18 (17.5%) ‐ in the left carotid circulation, and 14 (13.6%) in posterior circulation. TRA‐>TFA conversion occurred in 5 patients (4.8%), TFA‐>TRA ‐ in 1 patient (0.24%) all of which were due to prohibitive anatomy, rather than guide catheter limitations. There were no significant differences in baseline patient characteristics between the TRA and TFA groups. Angiographic outcomes (TICI 2B or greater) were similar for TRA vs TFA (96.1% vs 93.9%, p=0.39), as were good clinical outcome (discharge mRS 0‐2) rates (58% vs 55.4%, p=0.63). There was a trend towards shorter PT‐RT with TRA (29.5 min vs 38.3 min) although it did not reach statistical significance (p=0.11). No access‐related complications were noted with TRA. Conclusion Transradial thrombectomy using Sheathless PV Guide catheter is safe, effective, and offers substantial cost‐savings and shorter procedural times with low rate of access conversions, similar to other reported TRA thrombectomy series. Randomized trials are needed to validate its rates of technical success and complications against other frequently‐used TRA guide catheters.

Predictors of Angiographic Outcome After Failed Thrombectomy for Large Vessel Occlusion: Insights from the Stroke Thrombectomy and Aneurysm Registry.

Mechanical thrombectomy failure (MTF) occurs in approximately 15% of cases. To investigate factors that predict MTF. This was a retrospective review of prospectively collected data from the Stroke Thrombectomy and Aneurysm Registry. Patients who underwent mechanical thrombectomy (MT) for large vessel occlusion (LVO) were included. Patients were categorized by mechanical thrombectomy success (MTS) (≥mTICI 2b) or MTF (<mTICI 2b). Demographics, pretreatment, and treatment information were included in a univariate (UVA) and multivariate (MVA) analysis for prediction of MTF. A total of 6780 patients were included, and 1001 experienced anterior circulation MTF. Patients in the MTF group were older (73 vs 72, P = .044) and had higher poor premorbid modified Rankin Scale (mRS) (10.8% vs 8.4%, P = .017). Onset to puncture time was greater in the MTF group (273 vs 260 min, P = .08). No significant differences were found between the access site, use of balloon guide catheter, frontline technique, or first-pass devices between the MTF and MTS groups. More complications occurred in the MTF group (14% vs 5.8%), including symptomatic intracerebral hemorrhage (9.4% vs 6.1%) and craniectomies (10% vs 2.8%) ( P < .001). On UVA, age, poor pretreatment mRS, increased number of passes, and increased procedure time were associated with MTF. Internal carotid artery, M1, and M2 occlusions had decreased odds of MTF. Poor preprocedure mRS, number of passes, and procedure time remained significant on MVA. A subgroup analysis of posterior circulation LVO revealed that number of passes and total procedure time correlated with increased odds of MTF ( P < .001) while rescue stenting was associated with less odds of MTF (odds ratio 0.20, 95% CI 0.06-0.63). Number of passes remained significant on MVA of posterior circulation occlusion subgroup analysis. Anterior circulation MTF is associated with more complications and worse outcomes. No differences were found between techniques or devises used for the first pass during MT. Rescue intracranial stenting may decrease the likelihood of MTF for posterior circulation MT.

Is cardioembolic stroke more frequent than expected in acute ischemic stroke due to large vessel occlusion?

Cardioembolic and atherosclerotic occlusions are two leading causes of acute ischemic stroke with large artery occlusion. Cardioembolic cause is more frequent in strokes due to large vessel occlusion among strokes of all types. In this study, we aimed to analyze and determine the rate of cardioembolic cause in patients with LVO treated with mechanical thrombectomy. This study is a retrospective analysis of 1,169 patients with LVO that were treated with mechanical thrombectomy in 2019. Both anterior and posterior circulation occlusions eligible for thrombectomy were included. Among the 1,169 patients who performed mechanical thrombectomy, there were 52.6 % males with a mean age of 63.2 ± 12.9 years and 47.4% females with a mean age of 67.4 ± 13.3 years. The average NIHSS score was 15.3 ± 4.8. The successful revascularization (mTICI 2b-3) rate was 85.2%, the 90-day good functional outcome rate (mRS 0-2) was 39.8% and mortality (mRS 6) rate was 22.9%. Most common causes of ischemic stroke were cardioembolism in 532/1,169 (45.5%), followed by 461/1,169 (39.5%) undetermined etiologies and others, 175/1,169 (15%) large vessel disease. Atrial fibrillation is found to be the most common cause of cardioembolic stroke with 76.3% incidence. We identified 11 (0.9%) acute stroke patients treated with MT who had recurrent LVO and received repeated MT. A cardioembolic cause was found to cause the recurrent LVO in 7 (63.6%) patients. In this retrospective study, cardioembolic source seems to constitute majority of causes in acute ischemic strokes due to large vessel occlusions. Further exploration is needed especially in cryptogenic strokes to reveal possible cardioembolic source of emboli.

476 Technical and Clinical Outcomes in Concurrent Multivessel Occlusions Treated With Mechanical Thrombectomy: Insights from the STAR Collaboration

INTRODUCTION: Endovascular thrombectomy(EVT) has become the mainstay treatment of large vessel occlusion, however its role in the treatment of patients with simultaneous multi-territory occlusions(MVOs) has not been established. METHODS: We reviewed the STAR registry and included patient data from 35 stroke centers for EVT performed to treat bilateral anterior or concurrent anterior and posterior circulation occlusions from 2017-2020. RESULTS: We included a total of 7723 patients who underwent EVT for acute ischemic stroke. 54 patients (0.7%) underwent EVT for MVOs (mean age 69 ± 12.5; Female 50%). 28% had bilateral and 72% had concurrent anterior and posterior circulations occlusions. We used propensity score matching to match patients with MVOs to another group with single vessels occlusions by age, gender, race, admission NIHSS, baseline mRS score, onset to groin, use of IV-tPA. The rate of recanalization (TICI2B/3), complications, modified Rankin score at 90 days, and mortality was not significantly different between the 2 groups. Multivariate analysis confirmed that MVOs was not a predictor of poor functional outcome, increased symptomatic hemorrhage, or longer procedure time. CONCLUSIONS: Compared to single vessel occlusions, EVT in appropriately selected MVOs has similar efficacy and safety profile.

Mechanical thrombectomy for acute large vessel occlusion stroke beyond 24h.

Multiple trials have shown that mechanical thrombectomy (MT) is superior to medical therapy. However, no robust evidence is available regarding MT beyond 24h. In this study, we aimed to determine the safety and efficacy of endovascular stroke therapy in this late window. We conducted a retrospective study of prospectively collected data of patients who met extended window trial criteria, but underwent MT beyond 24h. Safety and efficacy outcomes included symptomatic intracerebral hemorrhage (sICH), procedural complications, number of passes, successful recanalization (mTICI 2b-3), delta (Δ) NIHSS (baseline-discharge), and favorable outcomes (mRS 0-2 at 90days). A total of 39 patients were included with a median age of 69years (IQR 61.5, 73.5); 54% were females. Hypertension was present in 76% of patients; 23% were smokers. Half of the patients had M1 occlusion (48.7%). Median preprocedural NIHSS was 11 (IQR 7.0, 19.5). Successful revascularization was achieved in 87%; median number of passes was 2 (IQR 1.0, 3.0). Median ΔNIHSS was 3.0 (IQR -1.5, 8.0). Favorable outcome was achieved in 49% (95% CI: 34%-64%), and 95% were free of complications. A total of 3 patients (7.7%) had sICH. In an exploratory analysis, posterior circulation occlusion was associated with higher mRS at 90days (OR: 14.7, p=0.016). Favorable discharge facility was associated with lower mRS at 90days (OR: 0.11, p=0.004). Our study showed comparable clinical outcomes of MT beyond 24h compared to MT trials within 24h in patients with favorable imaging profile, especially in anterior circulation occlusions.

April 2023 Stroke Highlights.

April 2023 Stroke Highlights.

Influencing factors of futile recanalization after endovascular therapy for cerebral infarction with posterior circulation occlusion of large vessels: a retrospective study

BackgroundThe optimal treatment for cerebral infarction caused by posterior circulation occlusion of large vessels has not yet been determined. Intravascular interventional therapy is an important treatment for cerebral infarction with posterior circulation occlusion of large vessels. However, endovascular therapy (EVT) of some posterior circulation cerebrovascular is ineffective and eventually become futile recanalization. Therefore, we performed a retrospective study to explore the factors influencing futile recanalization after EVT in patients with posterior circulation large-vessel occlusion.MethodsEighty-six patients with acute cerebral infarction and posterior circulation large vessel occlusion after intravascular intervention were divided into two groups according to their modified Rankin scale (mRS) scores after 3 months: group 1, mRS scores less than or equal to 3 (the effective recanalization group); group 2, mRS scores greater than 3 (the ineffective recanalization group). The basic clinical data, imaging index scores, time from onset to recanalization, and operation time between the two groups were compared and analyzed. Logistic regression was used to analyze the factors influencing indicators of good prognosis, and the ROC curve and Youden index were used to determine the best cutoff value.ResultsBetween the two groups, there were significant differences in the posterior circulation CT angiography (pc-CTA) scores, GCS scores, pontine midbrain index scores, time from discovery to recanalization, operation time, NIHSS score and incidence of gastrointestinal bleeding. The logistic regression revealed that the NIHSS score and time from discovery to recanalization were associated with good prognoses.ConclusionNIHSS score and recanalization time were independent influencing factors of ineffective recanalization of cerebral infarctions caused by posterior circulation occlusion. EVT is relatively effective for cerebral infarction caused by posterior circulation occlusion when the NIHSS score is less than or equal to 16 and the time from onset to recanalization is less than or equal to 570 min.

Abstract TP145: Mechanical Thrombectomy Beyond 24 Hours

Background: Multiple randomized controlled trials have shown that mechanical thrombectomy (MT) is superior to medical therapy. However, no robust evidence is available to assess the effectiveness of MT beyond the 24-hour window. In this study, we aimed to determine the safety and efficacy of MT in patients undergoing MT for stroke beyond 24 hours from last known normal (LKN). Methods: Retrospective review of a prospectively collected database for subjects who met extended window trial criteria, but underwent MT beyond 24 hours. Recorded variables included age, sex, NIHSS at baseline and at discharge, risk factors, level of occlusion, access site, thrombectomy method. Safety and efficacy outcomes included symptomatic intracerebral hemorrhage (sICH), procedural complications, number of passes, successful recanalization (TICI 2b-3), Δ NIHSS (baseline-discharge), favorable outcomes (mRS 0-2) at 90 days. Results: A total of 39 patients were included with a median age of 69 (IQR 61.5, 73.5); 54% were females. Hypertension was the most frequent risk factor in 76% of patients; 23 % of patients were smokers. Half of the patients had M1 occlusion (48.7%). Median preprocedural NIHSS was 11 (IQR 7.0, 19.5). Successful revascularization was achieved in 87%; median number of passes was 2 (IQR 1.0,3.0). Median ΔNIHSS was 3.0 (IQR -1.5, 8.0). Favorable outcome was achieved in 49% (95% CI: 34%-64%), and 95% were free of complications. A total of 3 patients (7.7%) had sICH. In an exploratory analysis, posterior circulation occlusion was associated with higher risk of poor mRS at 90 days (OR: 14.7, p = 0.016). Additionally, favorable discharge facility (home, home health, or rehab) was associated with a much lower risk of poor mRS at 90 days (OR: 0.11, p = 0.004). Conclusions: Our single center study of MT beyond 24 hours showed comparable clinical outcomes and safety profile to large MT trials within 24 hours, especially in anterior circulation occlusions. Posterior circulation occlusions were associated with worse outcomes, which warrants further investigation.

Abstract WP162: Primary Results Of Mechanical Thrombectomy For Acute Ischemic Stroke In Clinical Practice: K-net Registry

Background: Endovascular treatment (EVT) for acute large vessel occlusion has been found to be effective in several randomized controlled trials. We conducted a prospective cohort study to evaluate the real-world efficacy of EVT in patients with acute ischemic stroke in a metropolitan area with a high population density and a large number of comprehensive stroke centers. Methods: We analyzed the Kanagawa Intravenous and Endovascular Treatment of Acute Ischemic Stroke registry, a prospective, multicenter observational study of patients treated by EVT and/or intravenous tissue-type plasminogen activator (tPA), in Kanagawa, Japan. Of the 2488 patients enrolled from January 2018 to June 2020, 1764 patients treated with EVT were included. The primary outcome was a good outcome, which was defined as a modified Rankin Scale (mRS) of 0 to 2 at 90 days. Secondary analysis included predicting a good outcome using multivariate logistic regression analysis. Results: The median age was 77 years and the median National Institute of Health Stroke Scale (NIHSS) score was 18. Pretreatment mRS score 0-2 was 87%, and direct transport was 92%. The rate of occlusion in anterior circulation was 90.3%. Successful recanalization was observed in 88.7%. The median time from onset to recanalization was 193 minutes. Good outcomes at 90 days were 43.3% in anterior circulation and 41.9% in posterior circulation. Furthermore, 49.3% of patients with anterior circulation obstruction who had pre-stroke mRS 0-2 had good outcome, which was higher than the HERMES trial. Overall mortality was 12.6%. Significant predictors for a good outcome were: age, male, direct transfer, NIHSS score, Alberta Stroke Program Early Computed Tomography Score, intravenous tPA, and successful recanalization. Conclusions: EVT in routine clinical use in a metropolitan area showed comparable good outcomes and lower mortality compared to previous registries and RCTs, despite the high proportion of patients with older age, pretreatment mRS score of &gt; 2, posterior circulation occlusion, and higher NIHSS. Those results may have been associated with more direct transport and faster onset-to-recanalization times.

Abstract TP151: Predictors Of Mechanical Thrombectomy Failure

Background: Mechanical thrombectomy is standard of care for acute ischemic stroke secondary to LVO however MT failure (MTF) occurs in approximately 15% of cases. Objective: Investigate patient and procedural characteristics that predict MTF. Methods: Retrospective review of prospectively collected, Stroke Thrombectomy and Aneurysm Registry. Patients who underwent MT for LVO were included and categorized by MT Success (MTS) or MTF, defined as mTICI≥2b or &lt;mTICI2b, respectively. Demographics, pretreatment, and treatment information were included in UVA and MVA for prediction of MTF. Results: A total of 8452 patients were analyzed, and 1301(15.4%) experienced MTF.MTF patients were older(73 vs.71, p=0.008)had higher poor premorbid mRS(10.8% vs 8.4%, p=0.17).Onset to puncture was greater in MTF group(442 vs.411 min, p=0.006).There were more ICA occlusions(15.6% vs. 13.5%)and basilar occlusions(7.8% vs.6.2%)in the MTF group and more M1 occlusions(42.2%vs.37.5%)in the MTS group (p&lt;0.001).More patients underwent aspiration as the final technique in the MTS group(35.3% vs 32.9%).Number of passes(3 vs 2)and procedure time (77.3 vs 46.1 min) were higher in the MTF group (p&lt;0.001). More patients in the MTF group required IA thrombolytic(14.7% vs. 8.3%, p&lt;0.001).More patients in the MTS group had rescue stenting(7.9% vs 4.8%).There were more complications (14.7% vs 6.2%) and more symptomatic ICH(9.9% vs 5.7%, p&lt;0.001)in the MTF group. Favorable outcome at 90 days was greater in the MTS group(42.6% vs 18.3%, P&lt;0.001).On UVA, age, poor pretreatment mRS, posterior circulation occlusion, final technique SR, increased number of passes, increased procedure time were associated with increased odds of MTF, while M1-M2 occlusions and rescue intracranial stenting with decreased odds of MTF. These correlations remained significant on MVA for final technique SR, rescue intracranial stenting, number of passes, and procedure time. Conclusion: MTF is associated with more complications and worse outcome. Final use of aspiration and rescue intracranial stenting may increase chances of recanalization.

Technical and clinical outcomes in concurrent multivessel occlusions treated with mechanical thrombectomy: insights from the STAR collaboration

BackgroundEndovascular thrombectomy (EVT) has become the mainstay treatment for large vessel occlusion, with favorable safety and efficacy profile. However, the safety and efficacy of EVT in concurrent multi-territory occlusions (MTVOs)...

Rule-based natural language processing for automation of stroke data extraction: a validation study.

Data extraction from radiology free-text reports is time consuming when performed manually. Recently, more automated extraction methods using natural language processing (NLP) are proposed. A previously developed rule-based NLP algorithm showed promise in its ability to extract stroke-related data from radiology reports. We aimed to externally validate the accuracy of CHARTextract, a rule-based NLP algorithm, to extract stroke-related data from free-text radiology reports. Free-text reports of CT angiography (CTA) and perfusion (CTP) studies of consecutive patients with acute ischemic stroke admitted to a regional stroke center for endovascular thrombectomy were analyzed from January 2015 to 2021. Stroke-related variables were manually extracted as reference standard from clinical reports, including proximal and distal anterior circulation occlusion, posterior circulation occlusion, presence of ischemia or hemorrhage, Alberta stroke program early CT score (ASPECTS), and collateral status. These variables were simultaneously extracted using a rule-based NLP algorithm. The NLP algorithm's accuracy, specificity, sensitivity, positive predictive value (PPV), and negative predictive value (NPV) were assessed. The NLP algorithm's accuracy was > 90% for identifying distal anterior occlusion, posterior circulation occlusion, hemorrhage, and ASPECTS. Accuracy was 85%, 74%, and 79% for proximal anterior circulation occlusion, presence of ischemia, and collateral status respectively. The algorithm confirmed the absence of variables from radiology reports with an 87-100% accuracy. Rule-based NLP has a moderate to good performance for stroke-related data extraction from free-text imaging reports. The algorithm's accuracy was affected by inconsistent report styles and lexicon among reporting radiologists.

Successful Outcome in an Adolescent with Artery of Percheron Occlusion who was Treated with Tissue Plasminogen Activator

BackgroundIschemic stroke is relatively rare in children, leading to a low level of suspicion and delayed diagnosis, particularly in cases of posterior circulation occlusion when symptoms are less indicative. Occlusion of the artery of Percheron (AOP) results in nonspecific neurologic symptoms, including drowsiness, aphasia or dysarthria, ophthalmoplegia, ataxia, and dysmetria. Previous reports, mainly in adults, described late diagnosis and severe residual disability. Case ReportWe report a case of a 16-year-old male who presented to the pediatric emergency department with altered mental status. There was no history of trauma or intoxication. The main symptoms included confusion, slurred speech, and multiple falls starting 1 h before arrival to the emergency department. No motor deficits or other focal signs were noticed. The patient's consciousness gradually decreased followed by apneic events. Routine laboratory tests, urinary toxic screen, and a computed tomography scan of the head were normal. A magnetic resonance imaging scan of the brain revealed bilateral restrictive changes in the thalamus. A diagnosis of AOP occlusion was made, and the patient was treated with tissue plasminogen activator (6 h after symptom onset). He was extubated on day 4 and discharged on the day 10 of admission without any neuropsychological deficit. Why Should an Emergency Physician Be Aware of This?Posterior circulation stroke in the pediatric population is a diagnostic challenge that often results in suboptimal treatment and unfavorable outcomes. Prompt imaging studies in children with nonspecific altered mental status enable timely diagnosis and thrombolytic treatment that may substantially improve the outcome.

Practice enhancements with FastStroke ColorViz analysis in acute ischemic stroke.

In acute ischemic stroke (AIS), large vessel occlusion (LVO) and the status of pial collaterals are important factors in decision-making for further treatment such as endovascular therapy. Multiphasic CT Angiogram (mCTA) is the mainstay of AIS imaging, allowing detection of LVO, evaluation of intracranial arterial dynamics, and quantification of pial collaterals. However, thorough mCTA evaluation entails scrutiny of multiple image datasets, individually and then simultaneously, which can be time-consuming, causing a potential delay in treatment. ColorViz (FastStroke, GE Healthcare, Milwaukee, Wisconsin) is a novel CT application which combines mCTA information into a single color-coded dataset for quick, unequivocal evaluation of pial collaterals. In our practice, ColorViz is both time-saving and increases the diagnostic accuracy of LVO and pial collaterals as well as medium vessel, multivessel and posterior circulation occlusions. In this article, we discuss the practical aspects of ColorViz in patients presenting with AIS.