Remote Training of Neurointerventions by Audiovisual Streaming : Experiences from the European ESMINT-EYMINT E-Fellowship Program

BACKGROUND

Remote access of trainees to training centers via video streaming (tele-observership, e‑fellowship) emerges as an alternative to acquire knowledge in endovascular interventions. Situational awareness is a summary term that is also used in surgical procedures for perceiving and understanding the situation and projecting what will happen next. A high situational awareness would serve as prerequisite for meaningful learning success during tele-observerships. We hypothesized that live perception of the angiographical procedures using streaming technology is feasible and sufficient to gain useful situational awareness of the procedure.

METHODS

During a European tele-observership organized by the European Society of Minimally Invasive Neurological Therapy (ESMINT) and its trainee association (EYMINT), a total of six neurointerventional fellows in five countries observed live cases performed by experienced neurointerventionalists (mentors) in six different high-volume neurovascular centers across Europe equipped with live-streaming technology (Tegus Medical, Hamburg, Germany). Cases were prospectively evaluated during a 12-month period, followed by a final questionnaire after completion of the course.

RESULTS

A total of 102/161 (63%) cases with a 1:1 allocation of fellow and mentor were evaluated during a 12-month period. Most frequent conditions were ischemic stroke (27.5%), followed by embolization of unruptured aneurysms (25.5%) and arteriovenous malformations (AVMs) (15.7%). A high level of situational awareness was reported by fellows in 75.5% of all cases. After finishing the program, the general improvement of neurointerventional knowledge was evaluated to be extensive (1/6 fellows), substantial (3/6), and moderate (2/6). The specific fields of improvement were procedural knowledge (6/6 fellows), technical knowledge (3/6) and complication management (2/6).

CONCLUSION

Online streaming technology facilitates location-independent training of complex neurointerventional procedures through high levels of situational awareness and can therefore supplement live hands-on-training. In addition, it leads to a training effect for fellows with a perceived improvement of their neurointerventional knowledge.

Thrombectomy versus Medical Management for Isolated Anterior Cerebral Artery Stroke: An International Multicenter Registry Study

Background Evidence supporting a potential benefit of thrombectomy for distal medium vessel occlusions (DMVOs) of the anterior cerebral artery (ACA) is, to the knowledge of the authors, unknown. Purpose To compare the clinical and safety outcomes between mechanical thrombectomy (MT) and best medical treatment (BMT) with or without intravenous thrombolysis for primary isolated ACA DMVOs. Materials and Methods Treatment for Primary Medium Vessel Occlusion Stroke, or TOPMOST, is an international, retrospective, multicenter, observational registry of patients treated for DMVO in daily practice. Patients treated with thrombectomy or BMT alone for primary ACA DMVO distal to the A1 segment between January 2013 and October 2021 were analyzed and compared by one-to-one propensity score matching (PSM). Early outcome was measured by the median improvement of National Institutes of Health Stroke Scale (NIHSS) scores at 24 hours. Favorable functional outcome was defined as modified Rankin scale scores of 0-2 at 90 days. Safety was assessed by the occurrence of symptomatic intracerebral hemorrhage and mortality. Results Of 154 patients (median age, 77 years; quartile 1 [Q1] to quartile 3 [Q3], 66-84 years; 80 men; 94 patients with MT; 60 patients with BMT) who met the inclusion criteria, 110 patients (median age, 76 years; Q1-Q3, 67-83 years; 50 men; 55 patients with MT; 55 patients with BMT) were matched. DMVOs were in A2 (82 patients; 53%), A3 (69 patients; 45%), and A3 (three patients; 2%). After PSM, the median 24-hour NIHSS point decrease was -2 (Q1-Q3, -4 to 0) in the thrombectomy and -1 (Q1-Q3, -4 to 1.25) in the BMT cohort (P = .52). Favorable functional outcome (MT vs BMT, 18 of 37 [49%] vs 19 of 39 [49%], respectively; P = .99) and mortality (MT vs BMT, eight of 37 [22%] vs 12 of 39 [31%], respectively; P = .36) were similar in both groups. Symptomatic intracranial hemorrhage occurred in three (2%) of 154 patients. Conclusion Thrombectomy appears to be a safe and technically feasible treatment option for primary isolated anterior cerebral artery occlusions in the A2 and A3 segment with clinical outcomes similar to best medical treatment with and without intravenous thrombolysis. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Zhu and Wang in this issue.

Abstract WP164: Acute Carotid Stenting Versus Conservative Management For Tandem Carotid Occlusions: Insights From STAR

Introduction: Management of anterior circulation emergent large vessel occlusion with tandem carotid occlusion (TCO) remains a challenge during mechanical thrombectomy (MT). To day, there is no consensus regarding emergent carotid stenting (ECS) in the setting of MT with TCO. We aimed to compare the outcomes of ECS versus conservative management (MT alone) among patients with TCO.

Methods: Data from the Stroke Thrombectomy and Aneurysm Registry between 2010 and 2022 was interrogated. Only patients with concomitant occlusions of cervical carotid and proximal ipsilateral intracranial segments of the ICA or MCA were included in the analyses. We compared baseline, procedural charecteristics, successful reperfusion (mTICI 2b-3), favorable 90-day good outcomes (mRS 0-2), intravenous tPA administration and symptomatic ICH between patients who did or did not undergo ECS. Multivariate regression was performed adjusting for variables of clinical importance. Propensity score matching for IV tPA use was performed to explore its safety with stenting.

Results: Among 9812 thrombectomy patients, 688 patients had TCO; 132 underwent emergent stenting and 444 had MT alone. Patients who did not undergo ECS had a higher prevalence of atrial fibrillation (33.9% Vs 9.2%, P<.001), higher admission NIHSS scores (18 Vs 14, P<.001), shorter time from symptom onset to puncture (275 minutes Vs 333 minutes, P=0.029), and were predominantly women (59.2% Vs 33.6%, P<0.001).Patients with stenting had lower mortality rates ( 17.5% Vs 29.6%, P=0.009), and higher rates of successful reperfusion (83% Vs 95%, P=0.001). No difference in mRS 0-2 (37.5% Vs 30.4%, P=0.178) or sICH were seen (11.1% Vs 15.4%, P=0.219). Propensity score matching analysis (n=129 in each group) demonstrated better rates of reperfusion (94.8 Vs 84.4%, P=0.011) in the stenting group. Advanced age, higher admission NIHSS and lower ASPECT scores were associated with worse clinical outcomes.

Conclusion: ECS during MT for TCO appears to be safe and is associated with better clinical and angiographic outcomes compared to conservative management.

Abstract 54: Incidence And Predictors Of Dural Arteriovenous Fistulae After Cerebral Venous Sinus Thrombosis: Analysis Of ACTION-CVT

Background: Intracranial dural arteriovenous fistulae (DAVF) are uncommon vascular anomalies with a reported incidence of 0.2 per 100,000 person years. An association between cerebral venous thrombosis (CVT) and DAVF has been reported; however, the direction of causality between the two remains uncertain. We aimed to identify the incidence and predictors of development of DAVF among patients with CVT.

Methods: This is a post-hoc analysis of Anticoagulation in the Treatment of Cerebral Venous Thrombosis (ACTION-CVT), a multicenter retrospective study comparing outcomes of CVT patients treated with warfarin versus direct oral anticoagulants (DOACs) from 2015 to 2020. Patients were included in this analysis if they did not have DAVF on initial imaging and had follow-up vascular imaging during the study. Clinical, imaging, and anticoagulation characteristics of patients who developed DAVF were compared to those who did not. Stepwise binary logistic regression including important variables (achieving p<0.1 on univariate analyses) was used to determine predictors of DAVF development.

Results: A total of 751 patients (median age 43, 66% female) met inclusion criteria of whom 13 (1.7%) developed DAVF with an estimated rate of 2.40 per 100 patient years. Patients with DAVF were less likely to have headache at presentation (53.8% vs 79.3%, p=0.037), but more likely to have no venous recanalization on follow-up imaging (46.2% vs 14.8%, p=0.008), baseline cortical vein thrombosis (15.4% vs 2.7%, p=0.053), and received warfarin (vs. DOACs) as initial oral anticoagulant (84.6% vs 58.7%, p=0.085) but the latter two missed the statistical significance threshold. In stepwise binary logistic regression analysis, cortical vein thrombosis (OR 7.98, 95% CI 1.40-45.35, p=0.02) and lack of venous recanalization (OR 4.93, 95% CI 1.48-16.39, p=0.01) were associated with development of DAVF.

Conclusion: In this large multicenter study of CVT, the incidence of DAVF development was higher than the previously reported rate in the general population. The presence of cortical vein thrombosis and lack of venous recanalization were associated with increased risk of development of DAVF.

Abstract 48: Outcomes And Risk Of Hemorrhagic Transformation Following Mechanical Thrombectomy In Primary Distal Posterior Cerebral Artery Occlusions-subgroup Analysis From STAR

Background: While mechanical thrombectomy (MT) has become the standard of care for acute stroke patients presenting with large vessel occlusion (LVO) and salvageable brain tissue, limited data is currently available regarding the benefits of MT in patents with medium vessel occlusions (MeVO) especially in the posterior circulation (P2 occlusions).

Methods: We used the Stroke Thrombectomy and Aneurysm registry (STAR) which included data from 35 stroke centers in North America, Europe, Asia, and South America. We included patients who presented with MeVO in the M2, M3 or P2 segments and underwent MT. We used a Generalized Linear Model to assess the relationship between location of occlusion and outcomes.

Results: 9812 patients were included in STAR at the time of this analysis; 43 underwent MT for P2 occlusion, 130 underwent MT for M3 occlusion; and 1273 underwent MT for M2 occlusion. There was no difference in age, sex, race, rate of IV-tPA and stroke severity between patients in all 3 groups (Table 1). There was a trend toward lower rate of atrial fibrillation in patients with P2 and M3 occlusions. Patients with P2 occlusions were less likely to achieve successful recanalization (modified treatment in cerebral infarction score≥2b); intraarterial thrombolysis was used less in P2 occlusions (4.7% compared to 16.2% in M3 occlusions and 10.1% in M2 occlusions). However, there was no difference in the rate of successful first pass. On multivariable analysis, P2 occlusions were not associated with hemorrhagic transformation (OR 2.0, 95% CI 0.7-5.7, P 0.186), 90-day mortality (OR 0.5, 95% CI 0.2-1.4, P 0.183), or 90-day favorable outcome (OR 2.0, 95% CI 0.9-4.4, P 0.084).

Conclusions: In this multicenter study, there was no significant difference in safety and efficacy of MT in patients with MeVOs in posterior circulation (P2 occlusions) compared to M2 and M3 occlusions. Improved techniques for successful recanalization are needed for posterior circulation MeVOs.

Abstract TP150: Outcome Of Patients With Lacunar Strokes In The Era Of Thrombectomy

Introduction: Endovascular treatment (EVT), in particular mechanical thrombectomy, has dramatically improved the clinical outcome of patients with large vessels occlusion (LVO) of the anterior circulation. In contrast, the benefits of EVT cannot be applied to lacunar strokes (LS). The absence of a LVO in LS has been historically associated with a more favorable outcome, but in the new era of EVT, this assumption may not be correct anymore. We aimed to test the general assumption that LS have a better prognosis than other stroke subtypes, and analyze the outcome of LS treated with IVT as compared to strokes with LVO treated with IVT and/or mechanical thrombectomy in the multicentric Swiss Stroke Registry.

Methods: retrospective propensity score matching analysis of patients from the Swiss stroke registry (SSR) with lacunar stroke treated with thrombolysis versus LVO of the medial cerebral artery treated with EVT (with or without thrombolysis). Primary endpoint was a shift analysis of mRs at 90 days after stroke. Secondary outcomes were favorable functional outcome (mRS 0-1), independence (mRS 0-2), survival with high disability (mRS 3-5) and mortality (mRS 6) at 90 days.

Results: From 13'227 patients, the propensity score method matched (sex, age, NIHSS, time to treatment, prior anticoagulation, pre-stroke modified Rankin Score, mRs) 538 patients (269 in each group. There was no difference between groups in mRs shift analysis at 90 days after stroke (OR=0.99, 95%CI=0.73-1.35, p=0.952). There was also no significant difference in mRS 0-1 (59.9% vs 55.8% respectively; OR=0.79, 95%CI=0.55-1.16, p=0.75). LS+IVT patients showed a non-significant trend towards mRS 3-5 (OR=1.23, 95%CI=0.78-1.94, p=0.38), while patients treated with EVT had a slightly, non-significant, higher mortality (6.3% vs 1.9%, p=0.38).

Conclusions: Lacunar strokes - which cannot directly benefit from thrombectomy therapy - when treated with IVT and matched on key prognostic variables, seem to have similar outcomes as LVO strokes treated with EVT. This observation confirms that lacunar stroke is not a benign entity and therefore suggests that reperfusion therapy should be addressed with the same intensity as LVO stroke.

Abstract 98: The Impact Of Aspiration Catheter Size On Thrombectomy Outcomes Using Adapt Technique-analysis From The STAR Registry

Introductions: Clinical trials have shown that aspiration thrombectomy is as safe and effective as stent-retriever thrombectomy. Multiple improvements have been made to the aspiration technique over the last few years. In this study, we aim to assess the effect of aspiration catheter bore size on the outcomes of A direct aspiration first pass technique (ADAPT) thrombectomy.

Methods: We included patients who underwent ADAPT thrombectomy for M1 or internal carotid artery terminus (ICA-T) occlusions in the Stroke Thrombectomy and Aneurysm (STAR) database. Patients included between July 2016 and July 2022. We compared baseline characteristics, procedural metrics and outcomes between patients who underwent thrombectomy using small bore (0.035”-0.060”), medium bore (0.062”-0.068”) and large bore (0.070”-0.074”) catheters.

Results: A total of 1158 patients were included; 576 (49.7%) females, 645 (70%) White, and 464 (40.6%) received IV-tPA. No difference was noticed in age, sex, and vascular risk factors between the 3 different groups. There was higher rate of IV-tPA in the small-bore catheter group (48.8%) compared to the medium and large bore catheter groups (38.4% and 36.7%, respectively) (P=0.03). Procedure duration was shorter when using medium (20 min) and large (18 min) compared to small bore catheters (30 min) (P=0.01). Both medium and large bore catheters were associated with higher rate of successful recanalization (88.9% and 87.9%, respectively) compared to small bore catheters (81.6%) (P=0.010). However, the difference in successful recanalization or procedure duration between medium and large bore catheters was not significant. No difference was noted in the rate of symptomatic hemorrhagic transformation (sICH) (4.7%, 5.3%, and 7.1%; P=0.345), 90-day favorable outcome (modified Rankin Scale 0-2) (41.8%, 39.3%, 40.8%; P=0.766) or 90-day mortality (18.1%, 23.5%, 24.4%; P=0.111) between the groups.

Conclusions: Higher rate of successful recanalization and shorter procedure duration were observed when using medium and large bore aspiration catheters compared with small bore catheters in ADAPT technique. However, these procedural benefits were not observed when comparing large bore to medium bore catheters.

Abstract TP154: Outcomes Of Acute Carotid Stenting With Or Without Intravenous Thrombolysis Among Patients With Acute Tandem Occlusion: Insights From STAR

Introduction: Emergency carotid artery stenting during mechanical thrombectomy has emerged as an effective emergent treatment for tandem carotid occlusions. Nevertheless, scarce evidence is available about the safety of this procedure in patients who received intravenous tPA before thrombectomy. Herein, we investigate the safety of acute carotid stenting among patients who received intravenous tPA in a large international multicenter registry.

Methods: Patients from the Stroke Thrombectomy and Aneurysm Registry between 2010 and 2022 were analyzed. Only patients with concomitant occlusions of cervical carotid and proximal ipsilateral intracranial segments of the internal carotid or middle cerebral artery were included in the final analyses. Patients were divided into two groups, depending on tPA administration. The primary outcome was 90-day good clinical outcome (mRS 0-2), and the primary safety outcome was symptomatic intracranial hemorrhage. Univariate and multivariate regressions were performed adjusting for variables of clinical importance.

Results: Among 9812 with acute ischemic stroke in the registry, 132 patients had acute tandem occlusion and underwent carotid stenting; of those, 60 patients received IV tPA. Compared to non-intravenous thrombolytics, patients with IV tPA had a higher male prevalence (78.3% Vs 54.4%, P=0.005) and better ASPECT scores (9 Vs 8, P=0.022) with a shorter time from onset to puncture (241 Vs 672 minutes, P<0.001). There was no difference in rates of successful revascularization (94% Vs 95.5%, P=NS), good clinical outcome (50.8% Vs 61.4%, P=NS), symptomatic intracranial hemorrhage (15.3% Vs 14.5%, P=NS) or procedural complications (15% Vs 11.6%, P=NS) between the tPA and non-tPA groups.

Conclusion: The use of IV tPA did not affect the safety or efficacy of emergent carotid stenting in the setting of acute tandem occlusion.

Impact of Very Small Aneurysm Size and Anterior Communicating Segment Location on Outcome after Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Very small anterior communicating artery aneurysms (vsACoA) of <5 mm in size are detected in a considerable number of patients with aneurysmal subarachnoid hemorrhage (aSAH). Single-center studies report that vsACoA harbor particular risks when treated.

OBJECTIVE

To assess the clinical and radiological outcome(s) of patients with aSAH diagnosed with vsACoA after aneurysm treatment and at discharge.

METHODS

Information on n = 1868 patients was collected in the Swiss Subarachnoid Hemorrhage Outcome Study registry between 2009 and 2014. The presence of a new focal neurological deficit at discharge, functional status (modified Rankin scale), mortality rates, and procedural complications (in-hospital rebleeding and presence of a new stroke on computed tomography) was assessed for vsACoA and compared with the results observed for aneurysms in other locations and with diameters of 5 to 25 mm.

RESULTS

This study analyzed n = 1258 patients with aSAH, n = 439 of which had a documented ruptured ACoA. ACoA location was found in 38% (n = 144/384) of all very small ruptured aneurysms. A higher in-hospital bleeding rate was found in vsACoA compared with non-ACoA locations (2.8 vs 2.1%), especially when endovascularly treated (2.1% vs 0.5%). In multivariate analysis, aneurysm size of 5 to 25 mm, and not ACoA location, was an independent risk factor for a new focal neurological deficit and a higher modified Rankin scale at discharge. Neither very small aneurysm size nor ACoA location was associated with higher mortality rates at discharge or the occurrence of a peri-interventional stroke.

CONCLUSION

Very small ruptured ACoA have a higher in-hospital rebleeding rate but are not associated with worse morbidity or mortality.

Endovascular thrombectomy for basilar artery occlusion stroke: Analysis of the German Stroke Registry-Endovascular Treatment

BACKGROUND AND PURPOSE

Acute ischemic stroke due to basilar artery occlusion (BAO) causes the most severe strokes and has a poor prognosis. Data regarding efficacy of endovascular thrombectomy in BAO are sparse. Therefore, in this study, we performed an analysis of the therapy of patients with BAO in routine clinical practice.

METHODS

Patients enrolled between June 2015 and December 2019 in the German Stroke Registry-Endovascular Treatment (GSR-ET) were analyzed. Primary outcomes were successful reperfusion (modified Thrombolysis in Cerebral Infarction [mTICI] score of 2b-3), substantial neurological improvement (≥8-point National Institute of Health Stroke Scale [NIHSS] score reduction from admission to discharge or NIHSS score at discharge ≤1), and good functional outcome at 3 months (modified Rankin Scale [mRS] score of 0-2).

RESULTS

Out of 6635 GSR-ET patients, 640 (9.6%) patients (age 72.2 ± 13.3, 43.3% female) experienced BAO (median [interquartile range] NIHSS score 17 [8, 27]). Successful reperfusion was achieved in 88.4%. Substantial neurological improvement at discharge was reached by 45.5%. At 3-month follow-up, good clinical outcome was observed in 31.1% of patients and the mortality rate was 39.2%. Analysis of mTICI3 versus mTICI2b groups showed considerable better outcome in those with mTICI3 (38.9% vs. 24.4%; p = 0.005). The strongest predictors of good functional outcome were intravenous thrombolysis (IVT) treatment (odds ratio [OR] 3.04, 95% confidence interval [CI] 1.76-5.23) and successful reperfusion (OR 4.92, 95% CI 1.15-21.11), while the effect of time between symptom onset and reperfusion seemed to be small.

CONCLUSIONS

Acute reperfusion strategies in BAO are common in daily practice and can achieve good rates of successful reperfusion, neurological improvement and good functional outcome. Our data suggest that, in addition to IVT treatment, successful and, in particular, complete reperfusion (mTICI3) strongly predicts good outcome, while time from symptom onset seemed to have a lower impact.

Impact of edema formation on functional outcome in pediatric stroke patients

BACKGROUND

Quantitative lesion net water uptake (NWU) has been described as an imaging biomarker reflecting vasogenic edema as an early indicator of infarct progression. We hypothesized that edema formation measured by NWU is higher in children compared to adults but despite this functional outcome may be better in children.

METHODS

This study analyzed children enrolled in the Save ChildS Study who had baseline and follow-up computed tomography available and the data were compared to adult patients.

RESULTS

Some 207 patients, of whom 13 were children and 194 were adults, were analyzed. Median NWU at baseline was 7.8% (IQR: 4.3-11.3), and there were no significant differences between children and adults (7.5% vs. 7.8%; p = 0.87). The early edema progression rate was 3.0%/h in children and 2.3%/h in adults. Median ΔNWU was 15.1% in children and 10.5% in adults. Children had significantly more often excellent (mRS 0-1; children 10/13 = 77% vs. adults 28/196 = 14%; p < 0.0001) and favorable clinical outcomes (mRS 0-2, 12/13 = 92% vs. 39/196 = 20%; p < 0.0001).

CONCLUSIONS

In this study, clinical outcomes in children with large vessel occlusion strokes were better than in adults despite similar clinical and imaging characteristics and similar edema formation. This may be impacted by the generally better outcomes of children after strokes but may demonstrate that the degree of early ischemic changes using Alberta Stroke Program Early Computed Tomography Score (ASPECTS) and edema progression rate may not be a reason for exclusion from endovascular thrombectomy.

Predictors of Recurrent Venous Thrombosis After Cerebral Venous Thrombosis: Analysis of the ACTION-CVT Study

BACKGROUND AND OBJECTIVE

Cerebral venous thrombosis (CVT) is a rare cause of stroke carrying a nearly 4% risk of recurrence after 1 year. There are limited data on predictors of recurrent venous thrombosis in patients with CVT. In this study, we aim to identify those predictors.

METHODS

This is a secondary analysis of the ACTION-CVT study which is a multicenter international study of consecutive patients hospitalized with a diagnosis of CVT over a 6-year period. Patients with cancer-associated CVT, CVT during pregnancy, or CVT in the setting of known antiphospholipid antibody syndrome were excluded per the ACTION-CVT protocol. The study outcome was recurrent venous thrombosis defined as recurrent venous thromboembolism (VTE) or de novo CVT. We compared characteristics between patients with vs without recurrent venous thrombosis during follow-up and performed adjusted Cox regression analyses to determine important predictors of recurrent venous thrombosis.

RESULTS

Nine hundred forty-seven patients were included with a mean age of 45.2 years, 63.9% were women, and 83.6% had at least 3 months of follow-up. During a median follow-up of 308 (interquartile range 120-700) days, there were 5.05 recurrent venous thromboses (37 VTE and 24 de novo CVT) per 100 patient-years. Predictors of recurrent venous thrombosis were Black race (adjusted hazard ratio [aHR] 2.13, 95% CI 1.14-3.98, p = 0.018), history of VTE (aHR 3.40, 95% CI 1.80-6.42, p < 0.001), and the presence of one or more positive antiphospholipid antibodies (aHR 3.85, 95% CI 1.97-7.50, p < 0.001). Sensitivity analyses including events only occurring on oral anticoagulation yielded similar findings.

DISCUSSION

Black race, history of VTE, and the presence of one or more antiphospholipid antibodies are associated with recurrent venous thrombosis among patients with CVT. Future studies are needed to validate our findings to better understand mechanisms and treatment strategies in patients with CVT.

Multicenter investigation of technical and clinical outcomes after thrombectomy for Proximal Medium Vessel Occlusion (pMeVO) by frontline technique

BACKGROUND

Endovascular thrombectomy(EVT) is the standard of care for large vessel occlusion(LVO) stroke. Data on technical and clinical outcome in proximal medium vessel occlusions(pMeVOs) comparing frontline techniques remain limited.

METHODS

We report an international multicenter retrospective study of patients undergoing EVT for stroke at 32 centers between 2015-2021. Patients were divided into LVOs(ICA/M1/Vertebrobasilar) or pMeVOs(M2/A1/P1) and categorized by thrombectomy technique. Primary outcome was 90-day good functional outcome(mRS ≤ 2). Multivariate logistic regressions were used to evaluate the impact of technical variables on clinical outcomes. Propensity score matching was used to compare outcome in patients with pMeVO treated with aspiration versus stent-retriever.

RESULTS

In the cohort of 5977 LVO and 1287 pMeVO patients, pMeVO did not independently predict good-outcome(p  =  0.55). In pMeVO patients, successful recanalization irrespective of frontline technique(aOR = 3.2,p < 0.05), procedure time ≤ 1-h(aOR = 2.2,p < 0.05), and thrombectomy attempts ≤ 4(aOR =  2.8,p < 0.05) were independent predictors of good-outcomes.In a propensity-matched cohort of aspiration versus stent-retriever pMeVO patients, there was no difference in good-outcomes. The rates of hemorrhage were higher(9%vs.4%,p < 0.01) and procedure time longer(51-min vs. 33-min,p < 0.01) with stent-retriever, while the number of attempts was higher with aspiration(2.5vs.2,p < 0.01). Rates of hemorrhage and good-outcome showed an exponential relationship to procedural metrics, and were more dependent on time in the aspiration group compared to attempts in the stent-retriever group.

CONCLUSIONS

Clinical outcomes following EVT for pMeVO are comparable to those in LVOs. The golden hour or 3-pass rules in LVO thrombectomy still apply to pMeVO thrombectomy. Different techniques may exhibit different futility metrics; SR thrombectomy was more influenced by attempts whereas aspiration was more dependent on procedure time.

Mechanical Thrombectomy For Large Vessel Occlusion Between 6 And 24 Hours: Outcome Comparison Of Defuse-3/Dawn Eligible Versus Non-Eligible Patients

Background: The DEFUSE-3 and DAWN trials showed that mechanical thrombectomy (MT) improves the outcome of selected patients with large vessel occlusions in the anterior circulation (LVO) up to 24 hours of stroke onset. However, it is unknown whether only those patients fulfilling the trial inclusion criteria benefit, or whether benefit is seen in a broader range of patients presenting between 6 and 24 hours.

Aims: We determined whether fulfilling the DEFUSE-3 and DAWN selection criteria affects outcomes in MT patients in clinical practice.

Methods: We reviewed adult patients with LVO treated with MT between 6 and 24 hours after stroke onset at five Swiss stroke centers between 2014 and 2021. We compared two groups: (1) patients who satisfied neither DEFUSE-3 nor DAWN criteria (NDND); and (2) those who satisfied DEFUSE-3 or DAWN criteria (DOD). We used logistic regression to examine the impact of trial eligibility on two safety outcomes (symptomatic intracranial hemorrhage [sICH] and all-cause mortality at three months) and two efficacy outcomes (modified Rankin Score [mRS] shift toward lower categories and mRS of 0-2 at three months).

Results: Of 174 patients who received MT, 102 (59%) belonged to the NDND group. Rates of sICH were similar between the NDND group and the DOD group (3% vs. 4%, p=1.00). Multivariable regression revealed no differences in 3-month all-cause mortality (aOR 2.07, 95%CI 0.64-6.84, p=0.23) or functional outcomes (mRS shift: acOR 0.81, 95%CI 0.37-1.79, p=0.60; mRS 0-2: aOR 0.91, 95%CI 0.31-2.57, p=0.85).

Conclusion: Among adult patients with LVO treated with MT between 6 and 24 hours, safety and efficacy outcomes were similar between DEFUSE-3/DAWN eligible vs. ineligible patients. Our data provide a compelling rationale for randomized trials with broader inclusion criteria for MT.

Transradial versus transfemoral access for embolization of intracranial aneurysms with the Woven EndoBridge device: a propensity score-matched study

OBJECTIVE

Transradial access (TRA) is commonly utilized in neurointerventional procedures. This study compared the technical and clinical outcomes of the use of TRA versus those of transfemoral access (TFA) for intracranial aneurysm embolization with the Woven EndoBridge (WEB) device.

METHODS

This is a secondary analysis of the Worldwide WEB Consortium, which comprises multicenter data related to adult patients with intracranial aneurysms who were managed with the WEB device. These aneurysms were categorized into two groups: those who were treated with TRA or TFA. Patient and aneurysm characteristics and technical and clinical outcomes were compared between groups. Propensity score matching (PSM) was used to match groups according to the following baseline characteristics: age, sex, subarachnoid hemorrhage, aneurysm location, bifurcation aneurysm, aneurysm with incorporated branch, neck width, aspect ratio, dome width, and elapsed time since the last follow-up imaging evaluation.

RESULTS

This study included 682 intracranial aneurysms (median [interquartile range] age 61.3 [53.0-68.0] years), of which 561 were treated with TFA and 121 with TRA. PSM resulted in 65 matched pairs. After PSM, both groups had similar characteristics, angiographic and functional outcomes, and rates of retreatment, thromboembolic and hemorrhagic complications, and death. TFA was associated with longer procedure length (median 96.5 minutes vs 72.0 minutes, p = 0.006) and fluoroscopy time (28.2 minutes vs 24.8 minutes, p = 0.037) as compared with TRA. On the other hand, deployment issues were more common in those treated with TRA, but none resulted in permanent complications.

CONCLUSIONS

TRA has comparable outcomes, with shorter procedure and fluoroscopy time, to TFA for aneurysm embolization with the WEB device.

Outcome Prediction in Cerebral Venous Thrombosis: The IN-REvASC Score

BACKGROUND

We identified risk factors, derived and validated a prognostic score for poor neurological outcome and death for use in cerebral venous thrombosis (CVT).

METHODS

We performed an international multicenter retrospective study including consecutive patients with CVT from January 2015 to December 2020. Demographic, clinical, and radiographic characteristics were collected. Univariable and multivariable logistic regressions were conducted to determine risk factors for poor outcome, mRS 3-6. A prognostic score was derived and validated.

RESULTS

A total of 1,025 patients were analyzed with median 375 days (interquartile range [IQR], 180 to 747) of follow-up. The median age was 44 (IQR, 32 to 58) and 62.7% were female. Multivariable analysis revealed the following factors were associated with poor outcome at 90- day follow-up: active cancer (odds ratio [OR], 11.20; 95% confidence interval [CI], 4.62 to 27.14; P<0.001), age (OR, 1.02 per year; 95% CI, 1.00 to 1.04; P=0.039), Black race (OR, 2.17; 95% CI, 1.10 to 4.27; P=0.025), encephalopathy or coma on presentation (OR, 2.71; 95% CI, 1.39 to 5.30; P=0.004), decreased hemoglobin (OR, 1.16 per g/dL; 95% CI, 1.03 to 1.31; P=0.014), higher NIHSS on presentation (OR, 1.07 per point; 95% CI, 1.02 to 1.11; P=0.002), and substance use (OR, 2.34; 95% CI, 1.16 to 4.71; P=0.017). The derived IN-REvASC score outperformed ISCVT-RS for the prediction of poor outcome at 90-day follow-up (area under the curve [AUC], 0.84 [95% CI, 0.79 to 0.87] vs. AUC, 0.71 [95% CI, 0.66 to 0.76], χ2 P<0.001) and mortality (AUC, 0.84 [95% CI, 0.78 to 0.90] vs. AUC, 0.72 [95% CI, 0.66 to 0.79], χ2 P=0.03).

CONCLUSIONS

Seven factors were associated with poor neurological outcome following CVT. The INREvASC score increased prognostic accuracy compared to ISCVT-RS. Determining patients at highest risk of poor outcome in CVT could help in clinical decision making and identify patients for targeted therapy in future clinical trials.

European Stroke Organisation guidelines on treatment of patients with intracranial atherosclerotic disease

The aim of the present European Stroke Organisation guideline is to provide clinically useful evidence-based recommendations on the management of patients with intracranial atherosclerotic disease (ICAD). The guidelines were prepared following the Standard Operational Procedure of the European Stroke Organisation guidelines and according to GRADE methodology. ICAD represents a major cause of ischemic stroke worldwide, and patients affected by this condition are exposed to a high risk for future strokes and other major cardiovascular events, despite best medical therapy available. We identified 11 relevant clinical problems affecting ICAD patients and formulated the corresponding Population Intervention Comparator Outcomes (PICO) questions. The first two questions refer to the asymptomatic stage of the disease, which is being increasingly detected thanks to the routine use of noninvasive vascular imaging. We were not able to provide evidence-based recommendations regarding the optimal detection strategy and management of asymptomatic ICAD, and further research in the field is encouraged as subclinical ICAD may represent a big opportunity to improve primary stroke prevention. The second block of PICOs (3-5) is dedicated to the management of acute large vessel occlusion (LVO) ischemic stroke caused by ICAD, a clinical presentation of this disease that is becoming increasingly relevant and problematic, since it is associated with more refractory endovascular reperfusion procedures. An operational definition of probable ICAD-related LVO is proposed in the guideline. Despite the challenging context, no dedicated randomized clinical trials (RCTs) were identified, and therefore the guideline can only provide with suggestions derived from observational studies and our expert consensus, such as the escalated use of glycoprotein IIb-IIIa inhibitors and angioplasty/stenting in cases of refractory thrombectomies due to underlying ICAD. The last block of PICOs is devoted to the secondary prevention of patients with symptomatic ICAD. Moderate-level evidence was found to recommend against the use of oral anticoagulation as preferred antithrombotic drug, in favor of antiplatelets. Low-level evidence based our recommendation in favor of double antiplatelet as the antithrombotic treatment of choice in symptomatic ICAD patients, which we suggest to maintain during 90 days as per our expert consensus. Endovascular therapy with intracranial angioplasty and or stenting is not recommended as a treatment of first choice in high-grade symptomatic ICAD (moderate-level evidence). Regarding neurosurgical interventions, the available evidence does not support their use as front line therapies in patients with high-grade ICAD. There is not enough evidence as to provide any specific recommendation regarding the use of remote ischemic conditioning in ICAD patients, and further RCTs are needed to shed light on the utility of this promising therapy. Finally, we dedicate the last PICO to the importance of aggressive vascular risk factor management in ICAD, although the evidence derived from RCTs specifically addressing this question is still scarce.

Endovascular Therapy for Cerebral Vein Thrombosis: A Propensity-Matched Analysis of Anticoagulation in the Treatment of Cerebral Venous Thrombosis

BACKGROUND

Endovascular treatment (EVT) for cerebral vein thrombosis (CVT) has not been proven to be more effective than anticoagulation based on recent results of the Thrombolysis or Anticoagulation for Cerebral Venous Thrombosis (TO-ACT) randomized clinical trial.

OBJECTIVE

To compare outcomes of EVT vs medical management in CVT.

METHODS

We compared EVT vs medical management in a retrospective multinational cohort of consecutive patients with CVT across 4 countries (USA, Italy, Switzerland, and New Zealand) and 27 sites (2015-2020), using propensity score matching (PSM) and inverse probability treatment weighting (IPTW), and meta-analyzed these results with the TO-ACT trial. The primary outcome was excellent functional outcome (modified Rankin Scale [mRS] 0-1) at 90 days.

RESULTS

Of the 987 patients, the mean age was 45.7 ± 16.9 years and 79 (8%) underwent EVT. With PSM (n = 124), there were no major differences in clinical or imaging features between groups other than a higher proportion of female patients receiving EVT (81% vs 65%, P = .04). There was no difference in the primary outcome with PSM (odds ratio [OR] 1.48, 95% CI, 0.55-3.96) or IPTW (OR 1.02, 95% CI, 0.34-3.06). EVT was associated with a higher 90-day shift in modified Rankin Scale (OR 2.00, 95% CI, 1.01-3.98) and mortality with IPTW (OR 4.60, 95% CI, 1.10-19.23) but no other differences in secondary outcomes with PSM or IPTW. A meta-analysis of primary and secondary outcomes from TO-ACT and PSM patients from anticoagulation in the treatment of cerebral venous thrombosis also showed no significant association with EVT in primary or secondary outcomes.

CONCLUSION

In this large observational cohort, there was no evidence of benefit with EVT for CVT. These findings corroborate the results from the TO-ACT trial.

Bridging intravenous thrombolysis in patients with atrial fibrillation

Background and purpose

40% of acute ischemic stroke patients treated by mechanical thrombectomy (MT) have a clinical history of atrial fibrillation (AF). The safety of bridging intravenous thrombolysis (IVT) (MT + IVT) is currently being discussed. We aimed to analyze the interaction between oral anticoagulation (OAC) status or AF with bridging IVT, regarding the occurrence of symptomatic intracranial hemorrhage (sICH) and functional outcome.

Materials and Methods

Multicentric observational cohort study (BEYOND-SWIFT registry) of consecutive patients undergoing MT between 2010 and 2018 (n = 2,941). Multinomial regression models were adjusted for prespecified baseline and plausible pathophysiological covariates identified on a univariate analysis to assess the association of AF and OAC status with sICH and good outcomes (90-day modified Rankin Scale score 0–2).

Results

In the total cohort (median age 74, 50.6% women), 1,347 (45.8%) patients had AF. Higher admission National Institutes of Health Stroke Scale (NIHSS) score (aOR 1.04 [95% 1.02–1.06], per point of increase) and prior medication with Vitamin K antagonists (VKA) (aOR 2.19 [95% 1.27–3.66]) were associated with sICH. Neither AF itself (aOR 0.71 [95% 0.41–1.24]) nor bridging IVT (aOR 1.08 [0.67–1.75]) were significantly associated with increased sICH. Receiving bridging IVT (aOR 1.61 [95% 1.24–2.11]) was associated with good 90-day outcome, with no interaction between AF and IVT (p = 0.92).

Conclusion

Bridging IVT appears to be a reasonable clinical option in selected patients with AF. Given the increased sICH risk in patients with VKA, subgroup analysis of the randomized controlled trials should analyze whether patients with VKA might benefit from withholding bridging IVT.

Registration

clinicaltrials.gov; Unique identifier: NCT03496064.

Benefit of mechanical thrombectomy in acute ischemic stroke related to calcified cerebral embolus

PURPOSE

Mechanical thrombectomies (MT) in patients with large vessel occlusion (LVO) related to calcified cerebral embolus (CCE) have been reported, through small case series, being associated with low reperfusion rate and worse outcome, compared to regular MT. The purpose of the MASC (Mechanical Thrombectomy in Acute Ischemic Stroke Related to Calcified Cerebral Embolus) study was to evaluate the incidence of CCEs treated by MT and the effectiveness of MT in this indication.

METHODS

The MASC study is a retrospective multicentric (n = 37) national study gathering the cases of adult patients who underwent MT for acute ischemic stroke with LVO related to a CCE in France from January 2015 to November 2019. Reperfusion rate (mTICI ≥ 2B), complication rate and 90-day mRS were systematically collected. We then conducted a systematic review by searching for articles in PubMed, Cochrane Library, Embase and Google Scholar from January 2015 to March 2020. A meta-analysis was performed to estimate clinical outcome at 90 days, reperfusion rate and complications.

RESULTS

We gathered data from 35 patients. Reperfusion was obtained in 57% of the cases. Good clinical outcome was observed in 28% of the patients. The meta-analysis retrieved 136 patients. Reperfusion and good clinical outcome were obtained in 50% and 29% of the cases, respectively.

CONCLUSION

The MASC study found worse angiographic and clinical outcomes compared to regular thrombectomies. Individual patient-based meta-analysis including the MASC findings shows a 50% reperfusion rate and a 29% of good clinical outcome.

MRI or CT for Suspected Acute Stroke: Association of Admission Image Modality with Acute Recanalization Therapies, Workflow Metrics and Outcomes

Objective

To examine rates of intravenous thrombolysis (IVT), mechanical thrombectomy (MT), door‐to‐needle (DTN) time, door‐to‐puncture (DTP) time, and functional outcome between patients with admission magnetic resonance imaging (MRI) versus computed tomography (CT).

Methods

An observational cohort study of consecutive patients using a target trial design within the nationwide Swiss‐Stroke‐Registry from January 2014 to August 2020 was carried out. Exclusion criteria included MRI contraindications, transferred patients, and unstable or frail patients. Multilevel mixed‐effects logistic regression with multiple imputation was used to calculate adjusted odds ratios with 95% confidence intervals for IVT, MT, DTN, DTP, and good functional outcome (mRS 0–2) at 90 days.

Results

Of the 11,049 patients included (mean [SD] age, 71 [15] years; 4,811 [44%] women; 69% ischemic stroke, 16% transient ischemic attack, 8% stroke mimics, 6% intracranial hemorrhage), 3,741 (34%) received MRI and 7,308 (66%) CT. Patients undergoing MRI had lower National Institutes of Health Stroke Scale (median [interquartile range] 2 [0–6] vs 4 [1–11]), and presented later after symptom onset (150 vs 123 min, p < 0.001). Admission MRI was associated with: lower adjusted odds of IVT (aOR 0.83, 0.73–0.96), but not with MT (aOR 1.11, 0.93–1.34); longer adjusted DTN (+22 min [13–30]), but not with longer DTP times; and higher adjusted odds of favorable outcome (aOR 1.54, 1.30–1.81).

Interpretation

We found an association of MRI with lower rates of IVT and a significant delay in DTN, but not in DTP and rates of MT. Given the delays in workflow metrics, prospective trials are required to show that tissue‐based benefits of baseline MRI compensate for the temporal benefits of CT. ANN NEUROL 2022;92:184–194

Comparing treatment outcomes of various intracranial bifurcation aneurysms locations using the Woven EndoBridge (WEB) device

BACKGROUND

The Woven EndoBridge (WEB) device has Food and Drug Administration approval for treatment of wide-necked intracranial bifurcation aneurysms. The WEB device has been shown to result in adequate occlusion in bifurcation aneurysms overall, but its usefulness in the individual bifurcation locations has been evaluated separately only in few case series, which were limited by small sample sizes.

OBJECTIVE

To compare angiographic and clinical outcomes after treatment of bifurcation aneurysms at various locations, including anterior communicating artery (AComA), anterior cerebral artery (ACA) bifurcation distal to AComA, basilar tip, internal carotid artery (ICA) bifurcation, and middle cerebral artery (MCA) bifurcation aneurysms using the WEB device.

METHODS

A retrospective cohort analysis was conducted at 22 academic institutions worldwide to compare treatment outcomes of patients with intracranial bifurcation aneurysms using the WEB device. Data include patient and aneurysm characteristics, procedural details, angiographic and functional outcomes, and complications.

RESULTS

A total of 572 aneurysms were included. MCA (36%), AComA (35.7%), and basilar tip (18.9%) aneurysms were most common. The rate of adequate aneurysm occlusion was significantly higher for basilar tip (91.6%) and ICA bifurcation (96.7%) aneurysms and lower for ACA bifurcation (71.4%) and AComA (80.6%) aneurysms (p=0.04).

CONCLUSION

To our knowledge, this is the most extensive study to date that compares the treatment of different intracranial bifurcation aneurysms using the WEB device. Basilar tip and ICA bifurcation aneurysms showed significantly higher rates of aneurysm occlusion than other locations.

Effect of admission time on provision of acute stroke treatment at stroke units and stroke centers—An analysis of the Swiss Stroke Registry

Introduction:

Rapid treatment of acute ischemic stroke (AIS) depends on sufficient staffing which differs between Stroke Centers and Stroke Units in Switzerland. We studied the effect of admission time on performance measures of AIS treatment and related temporal trends over time.

Patients and methods:

We compared treatment rates, door-to-image-time, door-to-needle-time, and door-to-groin-puncture-time in stroke patients admitted during office hours (Monday–Friday 8:00–17:59) and non-office hours at all certified Stroke Centers and Stroke Units in Switzerland, as well as secular trends thereof between 2014 and 2019, using data from the Swiss Stroke Registry. Secondary outcomes were modified Rankin Scale and mortality at 3 months.

Results:

Data were eligible for analysis in 31,788 (90.2%) of 35,261 patients. Treatment rates for IVT/EVT were higher during non-office hours compared with office hours in Stroke Centers (40.8 vs 36.5%) and Stroke Units (21.8 vs 18.5%). Door-to-image-time and door-to-needle-time increased significantly during non-office hours. Median (IQR) door-to-groin-puncture-time at Stroke Centers was longer during non-office hours compared to office hours (84 (59–116) vs 95 (66–130) minutes). Admission during non-office hours was independently associated with worse functional outcome (1.11 [95%CI: 1.04–1.18]) and increased mortality (1.13 [95%CI: 1.01–1.27]). From 2014 to 2019, median door-to-groin-puncture-time improved and the treatment rate for wake-up strokes increased.

Discussion and Conclusion:

Despite differences in staffing, patient admission during non-office hours delayed IVT to a similar, modest degree at Stroke Centers and Stroke Units. A larger delay of EVT was observed during non-office hours, but Stroke Centers sped up delivery of EVT over time. Patients admitted during non-office hours had worse functional outcomes, which was not explained by treatment delays.

Aspiration Versus Stent Retriever Thrombectomy for Distal, Medium Vessel Occlusion Stroke in the Posterior Circulation: A Subanalysis of the TOPMOST Study

BACKGROUND

The optimal endovascular strategy for reperfusing distal medium-vessel occlusions (DMVO) remains unknown. This study evaluates angiographic and clinical outcomes of thrombectomy strategies in DMVO stroke of the posterior circulation.

METHODS

TOPMOST (Treatment for Primary Medium Vessel Occlusion Stroke) is an international, retrospective, multicenter, observational registry of patients treated for DMVO between January 2014 and June 2020. This study analyzed endovascularly treated isolated primary DMVO of the posterior cerebral artery in the P2 and P3 segment. Technical feasibility was evaluated with the first-pass effect defined as a modified Thrombolysis in Cerebral Infarction Scale score of 3. Rates of early neurological improvement and functional modified Rankin Scale scores at 90 days were compared. Safety was assessed by the occurrence of symptomatic intracranial hemorrhage and intervention-related serious adverse events.

RESULTS

A total of 141 patients met the inclusion criteria and were treated endovascularly for primary isolated DMVO in the P2 (84.4%, 119) or P3 segment (15.6%, 22) of the posterior cerebral artery. The median age was 75 (IQR, 62-81), and 45.4% (64) were female. The initial reperfusion strategy was aspiration only in 29% (41) and stent retriever in 71% (100), both achieving similar first-pass effect rates of 53.7% (22) and 44% (44; P=0.297), respectively. There were no significant differences in early neurological improvement (aspiration: 64.7% versus stent retriever: 52.2%; P=0.933) and modified Rankin Scale rates (modified Rankin Scale score 0-1, aspiration: 60.5% versus stent retriever 68.6%; P=0.4). In multivariable logistic regression analysis, the time from groin puncture to recanalization was associated with the first-pass effect (adjusted odds ratio, 0.97 [95% CI, 0.95-0.99]; P<0.001) that in turn was associated with early neurological improvement (aOR, 3.27 [95% CI, 1.16-9.21]; P<0.025). Symptomatic intracranial hemorrhage occurred in 2.8% (4) of all cases.

CONCLUSIONS

Both first-pass aspiration and stent retriever thrombectomy for primary isolated posterior circulation DMVO seem to be safe and technically feasible leading to similar favorable rates of angiographic and clinical outcome.