Intracranial Internal Carotid Artery Occlusion Research Articles

Effect of Endovascular Thrombectomy for Acute Ischemic Stroke on Cognitive Outcomes: A Secondary Analysis of the ESCAPE Trial.

The effect of endovascular therapy (EVT) for large vessel occlusion stroke on cognitive outcomes is not well understood. We evaluated the effect of EVT on cognitive function in the Endovascular Treatment for Small Core and Anterior Circulation Proximal Occlusion With Emphasis on Minimizing CT to Recanalization Times (ESCAPE) trial. Patient data from the ESCAPE randomized trial were analyzed. Cognitive assessments completed at 90 days after stroke were the Montreal Cognitive Assessment (MoCA), the Sunnybrook Neglect Assessment Procedure (SNAP), the Boston Naming Test (BNT), Trail-making test A (Trails A), and Trail-making test B (Trails B). We used logistic regression to evaluate the association between EVT and favorable cognitive outcome on the 5 separate tests, adjusting for demographic and clinical factors. We used generalized estimating equations and ordinal regression to determine the odds of favorable outcome with EVT on global cognition incorporating the 5 tests. We added final infarct volume (FIV) to the models to assess the relationship of FIV with cognitive outcome. The ESCAPE trial included 315 patients, 165 randomized to EVT and 150 randomized to control. There was higher odds of favorable outcome with EVT for MoCA (adjusted odds ratio [aOR] 2.32, 95% CI 1.30-4.16), SNAP (aOR 3.85, 95% CI 2.00-7.45), BNT (aOR 2.33, 95% CI 1.30-4.17), trails A (aOR 3.50, 95% CI 1.93-6.36), and trails B (aOR 2.56, 95% CI 1.46-4.48). There was higher odds of favorable outcome with EVT on global binary (aOR 2.57, 95% CI 1.67-3.94) and ordinal analyses (aOR 2.83, 95% CI 1.68-4.76) of cognitive function. After adding FIV to the models, both FIV and EVT were significantly associated with cognitive outcome. There was a significant correlation between global cognitive performance and mRS at day 90 (r = -0.78, p < 0.001), with the largest reductions in favorable cognitive outcome from mRS score 4 to 5 and from mRS 2 to 3. In this secondary analysis of the ESCAPE trial, EVT was associated with favorable outcome on 5 separate cognitive tests and in global analyses of cognitive benefit. These results provide novel evidence for the effect of EVT on cognition and support the global benefit of treatment with EVT. This study provides Class II evidence that in patients with acute ischemic stroke due to intracranial internal carotid artery (ICA) or M1 segment MCA occlusion, including tandem extracranial ICA occlusions, EVT compared with best medical therapy increased odds of favorable cognitive outcome.

Structural Analysis of Aspiration Catheters and Procedural Outcomes: An Analysis of the SVIN Registry

BACKGROUND Rapid expansion of mechanical thrombectomy and swift manufacturing development has translated into significant evolution of large‐bore catheter technology. The objective of this study was to evaluate the association among diverse structural components of large‐bore aspiration catheters on procedural performance. METHODS Retrospective analysis of a prospectively maintained mechanical thrombectomy consortium (SVIN [Society of Vascular Interventional Neurology] Registry) treated with stand‐alone contact aspiration for the first pass in the middle cerebral artery M1 or intracranial internal carotid artery occlusions from 2012 to 2021. Catheters were stratified on the basis of construction materials, tip technology, catheter sizing, and catheter lining. Factors associated with first‐pass effect (first‐pass eTICI 2c–3 reperfusion) as well as speed of clot engagement were analyzed. RESULTS We identified 983 patients with proximal occlusion and aspiration as the first‐pass technique. First‐pass effect was observed in 34% and associated with age (odds ratio [OR], 1.02 [95% CI, 1.01–1.03]), cardioembolic stroke pathogenesis (OR, 1.69 [95% CI, 1.77–2.41]), middle cerebral artery M1 (OR, 2.74 [95% CI, 1.09–1.87]), nongeneral anesthesia (OR, 0.55 [95% CI, 0.39–0.767]), as well as with 0.070‐inch (OR, 2.04 95% CI, 1.01–3.78]), and 0.088‐inch (OR, 3.90 [95% CI, 1.58–9.61]) distal catheter inner diameter in the adjusted analysis. Mean time from arterial access to clot contact was 17 minutes, with faster times observed in younger patients (OR, 0.99 [95% CI, 0.98–0.996]) as well as with the use of aspiration catheters with shorter length of distal outer hydrophilic coating (18–30 cm) on multivariable regression (OR, 0.30 [95% CI, 0.11–0.82]). CONCLUSION Larger aspiration catheter distal inner diameter was associated with higher rates of first‐pass effect. Aspiration catheter construction components were found to influence times from arterial access to clot contact.

Neurological Improvement by One-Thirds Is Associated With Early Recanalization in Stroke With Large Vessel Occlusion.

A proportion of large vessel occlusion strokes demonstrate early recanalization, obviating the initial intention to proceed to endovascular thrombectomy. Neurological improvement is a possible surrogate marker for reperfusion. We aimed to determine the optimal threshold of neurological improvement, as defined by the National Institutes of Health Stroke Scale (NIHSS), which best associates with early recanalization. We retrospectively analyzed consecutive patients with large vessel occlusion transferred from primary stroke centers to a tertiary comprehensive stroke center in Melbourne, Australia, for possible endovascular thrombectomy from January 2018 to December 2022. Absolute and percentage changes in NIHSS between transfer, as well as other definitions of neurological improvement, were compared using receiver operating characteristic curve analysis for association with recanalization as defined by the absence of occlusion in the internal carotid artery, middle cerebral artery (M1 or M2 segments), or basilar artery on repeat vascular imaging. Six hundred and fifty-four transferred patients with large vessel occlusion were included in the analysis: mean age was 68.8±14.0 years, 301 (46.0%) were women, and 338 (52%) received intravenous thrombolytics. The proportion of extracranial internal carotid artery, intracranial internal carotid artery, M1, proximal M2, and basilar artery occlusion was 18.8%, 13.6%, 48.3%, 15.0%, and 4.3%, respectively, on initial computed tomography angiogram. Median NIHSSprimary stroke center and NIHSScomprehensive stroke center scores were 15 (interquartile range, 9-18) and 13 (interquartile range, 8-19), respectively. Early recanalization occurred in 82 (13%) patients. NIHSS reduction of ≥33% was the best tradeoff between sensitivity (64%) and specificity (83%) for identifying recanalization. NIHSS reduction of ≥33% had the highest discriminative ability to predict recanalization (area under the curve, 0.735) in comparison with other definitions of neurological improvement. One-third neurological improvement between the primary hospital and tertiary center was the best predictor of early recanalization.

Endovascular thrombectomy for large ischemic strokes: meta-analysis of six multicenter randomized controlled trials

BackgroundSix randomized controlled trials have concluded their investigations on the efficacy and safety of endovascular thrombectomy (EVT) for patients with large infarcts.To synthesize the results from six trials which met...

Large vessel occlusion prediction scale thresholds that are sensitive for DAWN Trial patients

Background Large vessel occlusion (LVO) prediction scales are used to triage prehospital suspected stroke patients with a high probability of LVO stroke to endovascular therapy centers. The sensitivities of these scales in the 6-to-24-h time window are unknown. Higher scale score thresholds are typically less sensitive and more specific. Knowing the highest scale score thresholds that remain sensitive could inform threshold selection for clinical use. Sensitivities may also vary between left and right-sided LVOs. Methods LVO prediction scale scores were retrospectively calculated using the National Institutes of Health Stroke Scale (NIHSS) scores of patients enrolled in the DAWN Trial. All patients had last known well times between 6 and 24 h, NIHSS scores ≥ 10, intracranial internal carotid artery or proximal middle cerebral artery occlusions, and mismatches between their clinical severities and infarct core volumes. Scale thresholds with sensitivities ≥ 85% were identified, along with scores ≥ 5% more sensitive for left or right-sided LVOs. Specificities could not be calculated because all patients had LVOs. Results A total of 201 out of 206 patients had the required NIHSS subitem scores. CPSS = 3, C-STAT ≥ 2, FAST-ED ≥ 4, G-FAST ≥ 3, RACE ≥ 5, and SAVE ≥ 3 were the highest thresholds that were still 85% sensitive for DAWN Trial LVO stroke patients. RACE ≥ 5 was the only typically used score threshold more sensitive for right-sided LVOs, though similar small differences were seen for other scales at higher thresholds. Conclusions Our findings likely represent the maximum sensitivities of the LVO prediction scales tested for ideal thrombectomy candidates in the 6-to-24-h time window because NIHSS scores were documented in hospitals during a clinical trial rather than in the prehospital setting. Patients with NIHSS scores &lt; 10 or more distal LVOs would lower sensitivities further. Selecting even higher scale thresholds for LVO triage would lead to many missed LVO strokes.

No Sex Differences in Mechanical Thrombectomy Time Metrics and Outcomes in Saskatchewan.

Numerous studies have shown longer pre-hospital and in-hospital workflow times and poorer outcomes in women after acute ischemic stroke (AIS) in general and after endovascular treatment (EVT) in particular. We investigated sex differences in acute stroke care of EVT patients over 5 years in a comprehensive Canadian provincial registry. Clinical data of all AIS patients who underwent EVT between January 2017 and December 2022 in the province of Saskatchewan were captured in the Canadian OPTIMISE registry and supplemented with patient data from administrative data sources. Patient baseline characteristics, transport time metrics, and technical EVT outcomes between female and male EVT patients were compared. Three-hundred-three patients underwent EVT between 2017 and 2022: 144 (47.5%) women and 159 (52.5%) men. Women were significantly older (median age 77.5 [interquartile range: 66-85] vs.71 [59-78], p < 0.001), while men had more intracranial internal carotid artery occlusions (48/159 [30.2%] vs. 26/142 [18.3%], p = 0.03). Last-known-well to comprehensive stroke center (CSC)-arrival time (median 232 min [interquartile range 90-432] in women vs. 230 min [90-352] in men), CSC-arrival-to-reperfusion time (median 108 min [88-149] in women vs. 102 min [77-141] in men), reperfusion status (successful reperfusion 106/142 [74.7%] in women vs. 117/158 [74.1%] in men) as well as modified Rankin score at 90 days did not differ significantly. This held true after adjusting for baseline variables in multivariable analyses. While women undergoing EVT in the province of Saskatchewan were on average older than men, they were treated just as fast and achieved similar technical and clinical outcomes compared to men.

Imaging features of cardioembolic stroke on 4-dimensional computed tomography angiography.

Identifying cardioembolic stroke is important for the decision-making of endovascular treatment and anticoagulation therapy. We aimed to explore the features of cardioembolic stroke on 4-dimensional (4D) computed tomography angiography (4D-CTA) and assess whether these features can assist in classifying stroke etiology. In this retrospective study, we analyzed the images of 294 patients with acute ischemic stroke (AIS) from July 2020 to February 2022 at the First Affiliated Hospital of Chongqing Medical University, which had been consecutively collected. The data of 110 patients with occlusion of the M1/M2 segment of the middle cerebral artery (MCA) with/without intracranial internal carotid artery (ICA) occlusion were analyzed to calculate the clot burden score (CBS) and collateral score (CS), and the data of 88 patients with a clear origin and distal part were analyzed to measure clot length. Maximum intensity projection (MIP) and time MIP (tMIP) post-processing were used to assess the clot features. The Mann-Whitney U test was used to compare the clot characteristics between the 2 groups. Binary logistic regression was performed to assess the association between the image characteristics and cardioembolic stroke. Moreover, the receiver operating characteristic (ROC) curve was used to test the diagnostic efficacy of MIP/tMIP clot features in classifying cardioembolic stroke. Age, high-risk factors for cerebrovascular disease, high/medium-risk sources of cardioembolic stroke, clot length, CBS, and CS were significantly different between the cardioembolic stroke group and non-cardioembolic stroke group (P<0.05). In the cardioembolic stroke group, the median MIP and tMIP clot length was 12 mm [interquartile range (IQR), 8.3-17.4 mm] and 9.3 mm (IQR, 6.8-14.3 mm), respectively. In the non-cardioembolic stroke group, the median MIP and tMIP clot length was 6.5 mm (IQR, 4.7-11.5 mm) and 5.8 mm (IQR, 3.9-10.6 mm), respectively. Binary logistic regression showed that cardioembolic stroke was significantly associated with MIP-clot length [odds ratio (OR), 1.15; 95% confidence interval (CI): 1.02-1.29; P<0.05], tMIP-clot length (OR, 1.18; 95% CI: 1.02-1.36; P<0.05), and tMIP-CBS (OR, 3.96; 95% CI: 1.08-14.58; P<0.05). The area under the ROC curve (AUC) values of MIP clot length for identifying cardioembolic stroke were 0.75 (95% CI: 0.65-0.84, P<0.05), with a cut-off value of >7.4 mm [sensitivity: 84.62% (95% CI: 69.50-94.10%); specificity: 59.18% (95% CI: 44.20-73.00%)]. The AUC value of tMIP clot length was 0.72 (95% CI: 0.61-0.81, P<0.05), with a cut-off value of >5.4 mm [sensitivity: 92.31% (95% CI: 79.10-98.40%); specificity: 48.98% (95% CI: 34.40-63.70%)]. Clot length and CBS were overestimated on MIP images. Among the clot characteristics, clot length could identify cardioembolic stroke.

Single vs. Multiphase Computed Tomography angiography in acute internal carotid artery occlusion: An accuracy and interobserver agreement study

ObjectiveAccurate differentiation between the intracranial and extracranial location of the acute internal carotid artery (ICA) occlusion is essential for guiding treatment decisions and mechanical thrombectomy planning. Multiphase Computed Tomography angiography (mCTA) appears to be superior to Single-phase Computed Tomography angiography (sCTA) in the evaluation of acute ICA occlusions. The main objective of our research is to study the accuracy of mCTA compared to sCTA in distinguishing isolated acute intracranial ICA occlusion from extracranial or tandem occlusion. MethodsTwo observers independently analyzed sCTA and mCTA of patients with acute ICA occlusion at two different time points. The location of the occlusion was categorized as intracranial or extracranial for both imaging techniques and then compared with digital subtraction angiography (gold standard). Sensitivity and specificity rates for isolated intracranial ICA occlusion on sCTA and mCTA were calculated. Kappa statistics were used to assess interobserver agreement. ResultsThe sensitivity of sCTA and mCTA was 48.28% (28.36%–68.19%) and 79.31% (62.84%–95.78%) respectively for the diagnosis of isolated intracranial ICA occlusion, with an almost perfect interobserver agreement between both observers (p < 0.001). ConclusionsOur research suggests that mCTA is more accurate than sCTA in distinguishing isolated intracranial occlusions from extracranial or tandem occlusions.

Safety and Efficacy of Tenecteplase Compared With Alteplase in Patients With Large Vessel Occlusion Stroke

It is unknown whether intravenous thrombolysis using tenecteplase is noninferior or preferable compared with alteplase for patients with acute ischemic stroke. To examine the safety and efficacy of tenecteplase compared to alteplase among patients with large vessel occlusion (LVO) stroke. This was a prespecified analysis of the Intravenous Tenecteplase Compared With Alteplase for Acute Ischaemic Stroke in Canada (ACT) randomized clinical trial that enrolled patients from 22 primary and comprehensive stroke centers across Canada between December 10, 2019, and January 25, 2022. Patients 18 years and older with a disabling ischemic stroke within 4.5 hours of symptom onset were randomly assigned (1:1) to either intravenous tenecteplase or alteplase and were monitored for up to 120 days. Patients with baseline intracranial internal carotid artery (ICA), M1-middle cerebral artery (MCA), M2-MCA, and basilar occlusions were included in this analysis. A total of 1600 patients were enrolled, and 23 withdrew consent. Intravenous tenecteplase (0.25 mg/kg) vs intravenous alteplase (0.9 mg/kg). The primary outcome was the proportion of modified Rankin scale (mRS) score 0-1 at 90 days. Secondary outcomes were an mRS score from 0 to 2, mortality, and symptomatic intracerebral hemorrhage. Angiographic outcomes were successful reperfusion (extended Thrombolysis in Cerebral Infarction scale score 2b-3) on first and final angiographic acquisitions. Multivariable analyses (adjusting for age, sex, National Institute of Health Stroke Scale score, onset-to-needle time, and occlusion location) were carried out. Among 1577 patients, 520 (33.0%) had LVO (median [IQR] age, 74 [64-83] years; 283 [54.4%] women): 135 (26.0%) with ICA occlusion, 237 (45.6%) with M1-MCA, 117 (22.5%) with M2-MCA, and 31 (6.0%) with basilar occlusions. The primary outcome (mRS score 0-1) was achieved in 86 participants (32.7%) in the tenecteplase group vs 76 (29.6%) in the alteplase group. Rates of mRS 0-2 (129 [49.0%] vs 131 [51.0%]), symptomatic intracerebral hemorrhage (16 [6.1%] vs 11 [4.3%]), and mortality (19.9% vs 18.1%) were similar in the tenecteplase and alteplase groups, respectively. No difference was noted in successful reperfusion rates in the first (19 [9.2%] vs 21 [10.5%]) and final angiogram (174 [84.5%] vs 177 [88.9%]) among 405 patients who underwent thrombectomy. The findings in this study indicate that intravenous tenecteplase conferred similar reperfusion, safety, and functional outcomes compared to alteplase among patients with LVO.

The Society of Vascular and Interventional Neurology (SVIN) Mechanical Thrombectomy Registry: Outcomes in Patients With Acute Ischemic Stroke and COVID‐19

Background Clinical and radiographic outcomes after mechanical thrombectomy in the setting of COVID‐19 infection remain poorly characterized. We sought to determine how COVID‐19 status affects mechanical thrombectomy outcomes in the real‐world setting in the United States. Methods The prospectively maintained multicenter mechanical thrombectomy registry from the Society of Vascular and Interventional Neurology was queried for baseline clinical characteristics among patients with and without COVID‐19 who underwent mechanical thrombectomy between March 1 and December 31, 2020 at 12 sites. Primary outcome was the likelihood of good neurological outcomes (90 day modified Rankin scale 0–2) among patients with COVID‐19 treated with endovascular thrombectomy, which was assessed using multivariable logistic regression adjusted for age, National Institutes of Health Stroke Scale, Alberta Stroke Program Early CT Score, and substantial reperfusion (modified Thrombolysis in Cerebral Infarction 2b, 2c, and 3). Secondary outcomes included National Institutes of Health Stroke Scale at 24 hours. Results Among 915 patients who underwent mechanical thrombectomy during the study period, 51 patients were positive for COVID‐19 (5.6%). Univariate analysis revealed that compared with patients who were COVID‐19 negative, patients who were positive for COVID‐19 were more likely to be male, nonsmokers, have lower Alberta Stroke Program Early CT Score, and present with intracranial internal carotid artery occlusions (Table 1). They were also less likely to achieve successful reperfusion. Multivariable analysis, however, failed to identify any independent associations with COVID‐19 positive status. Conclusion In our cohort, patients postive for COVID‐19 with acute ischemic stroke who undergo mechanical thrombectomy have similar baseline characteristics, imaging features, procedural, and clinical outcomes compared to patients who are negative for COVID‐19 in multivariate analysis. Further analyses are warranted.

Assessing the Relationship between LAMS and CT Perfusion Parameters in Acute Ischemic Stroke Secondary to Large Vessel Occlusion.

The Los Angeles Motor Scale (LAMS) is a rapid pre-hospital scale used to predict stroke severity which has also been shown to accurately predict large vessel occlusions (LVOs). However, to date there is no study exploring whether LAMS correlates with the computed tomography perfusion (CTP) parameters in LVOs. Patients with LVO between September 2019 and October 2021 were retrospectively reviewed and included if the CTP data and admission neurologic exams were available. The LAMS was documented based on emergency personnel exams or scored retrospectively using an admission neurologic exam. The CTP data was processed by RAPID (IschemaView, Menlo Park, CA, USA) with an ischemic core volume (relative cerebral blood flow [rCBF] < 30%), time-to-maximum (Tmax) volume (Tmax > 6 s delay), hypoperfusion index (HI), and cerebral blood volume (CBV) index. Spearman's correlations were performed between the LAMS and CTP parameters. A total of 85 patients were included, of which there were 9 intracranial internal carotid artery (ICA), 53 proximal M1 branch middle cerebral artery M1, and 23 proximal M2 branch occlusions. Overall, 26 patients had LAMS 0-3, and 59 had LAMS 4-5. In total, LAMS positively correlated with CBF < 30% (Correlation Coefficient (CC): 0.32, p < 0.01), Tmax > 6 s (CC:0.23, p < 0.04), HI (CC:0.27, p < 0.01), and negatively correlated with the CBV index (CC:-0.24, p < 0.05). The relationships between LAMS and CBF were < 30% and the HI was more pronounced in M1 occlusions (CC:0.42, p < 0.01; 0.34, p < 0.01 respectively) and proximal M2 occlusions (CC:0.53, p < 0.01; 0.48, p < 0.03 respectively). The LAMS also correlated with a Tmax > 6 s in M1 occlusions (CC:0.42, p < 0.01), and negatively correlated with the CBV index in M2 occlusions (CC:-0.69, p < 0.01). There were no significant correlations between the LAMS and intracranial ICA occlusions. The results of our preliminary study indicate that the LAMS is positively correlated with the estimated ischemic core, perfusion deficit, and HI, and negatively correlated with the CBV index in patients with anterior circulation LVO, with stronger relationships in the M1 and M2 occlusions. This is the first study showing that the LAMS may be correlated with the collateral status and estimated ischemic core in patients with LVO.

Effects of endovascular recanalization on symptomatic non-acute occlusion of intracranial arteries

To investigate the effect and safety of recanalization surgery for non-acute occlusion of large intracranial arteries and factors affecting clincial outcomes. Patients with non-acute occlusion of internal carotid artery (ICA), middle cerebral artery (MCA), and vertebrobasilar artery (VBA) treated with recanalization were retrospectively enrolled. The clinical and angiographic data were analyzed. 177 patients were enrolled, including 67 patients with intracranial ICA occlusion, 52 with MCA occlusion, and 58 with VBA occlusion. Successful recanalization was achieved in 152 (85.9%) patients. Complications occurred in 15 patients (8.5%). Followed up for 3–7 months, the 90 day mRS was significantly improved compared with that before the procedure. Among 152 patients with successful recanalization, eight patients experienced reocclusion (5.3%), and 11 patients experienced restenosis (7.2%). Successful recanalization was significantly (P < 0.05) associated with occlusion duration, calcification or angulation of the occluded segment. Complications were significantly (P < 0.05) associated with location of occlusion, hyperlipidemia, and patients’ height. Restentosis or reocclusion at follow-up was significantly (P < 0.05) associated with complications and mRS at 90 days. The significant (P < 0.05) independent risk factors were angulation and calcification for successful recanalization, hyperlipidemia for complications, and mRS at 90 days for restenosis or reocclusion at follow-up. Recanalization surgery may be a safe and effective approach for patients with non-acute symptomatic occlusion of large intracranial arteries, and factors significantly independently associated with successful recanalization, periprocedural complications and restenosis or reocclusion after surgery have been identified for future reference to improve clinical outcomes.

Reperfusion Treatments in Disabling Versus Nondisabling Mild Stroke due to Anterior Circulation Vessel Occlusion.

The benefit of distinguishing between disabling versus nondisabling deficit in mild acute ischemic stroke due to endovascular thrombectomy-targetable vessel occlusion (EVT-tVO; including anterior circulation large and medium-vessel occlusion) is unknown. We compared safety and efficacy of acute reperfusion treatments in disabling versus nondisabling mild EVT-tVO. From the Safe Implementation of Treatments in Stroke-International Stroke Thrombolysis Register, we included consecutive acute ischemic stroke patients (2015-2021) treated within 4.5 hours, with full NIHSS items availability and score ≤5, evidence of intracranial internal carotid artery, M1, A1-2, or M2-3 occlusion. After propensity score matching, we compared efficacy (3-month modified Rankin Scale score of 0-1, modified Rankin Scale score of 0-2, and early neurological improvement) and safety (nonhemorrhagic early neurological deterioration, any intracerebral or subarachnoid hemorrhage, symptomatic intracranial hemorrhage, and death at 3-month) outcomes in disabling versus nondisabling patients-adopting an available definition. We included 1459 patients. Propensity score matched analysis of disabling versus nondisabling EVT-tVO (n=336 per group) found no significant differences in efficacy (modified Rankin Scale score 0-1: 67.4% versus 71.5%, P=0.336; modified Rankin Scale score 0-2: 77.1% versus 77.6%, P=0.895; early neurological improvement: 38.3% versus 44.4%, P=0.132) and safety (nonhemorrhagic early neurological deterioration: 8.5% versus 8.0%, P=0.830; any intracerebral hemorrhage or subarachnoid hemorrhage: 12.5% versus 13.3%, P=0.792; symptomatic intracranial hemorrhage: 2.6% versus 3.4%, P=0.598; and 3-month death: 9.8% versus 9.2%, P=0.844) outcomes. We found similar safety and efficacy outcomes after acute reperfusion treatment in disabling versus nondisabling mild EVT-tVO; our findings suggest to adopt similar acute treatment approaches in the 2 groups. Randomized data are needed to clarify the best reperfusion treatment in mild EVT-tVO.

Parallel stent retriever mechanical thrombectomy of an acute internal carotid artery occlusion refractory to standard techniques: A case report

Although mechanical thrombectomy for acute large vessel occlusion is generally effective, some occlusions are refractory. We report a patient in whom the parallel stent retriever technique using two Trevo stent retrievers (Stryker Neurovascular, Fremont, California, USA) was required to treat an intracranial and epidural internal carotid artery occlusion after other techniques had failed. A 68-year-old woman presented with an acute left internal carotid artery occlusion 4 days after mechanical thrombectomy of a left middle cerebral artery occlusion. She was not a candidate for intravenous thrombolysis because of a recent cerebral infarction. Attempts at mechanical thrombectomy using a stent retriever, contact aspiration, or combined contact aspiration and stent retriever were unsuccessful. The parallel stent retriever technique using two 6 × 25-mm Trevo stent retrievers enabled coverage of the entire thrombus, and successful reperfusion was achieved (extended Thrombolysis in Cerebral Infarction grade 2b). After the procedure, the patient was able to walk without assistance. Her modified Rankin Scale score was 2 at 90 days follow-up. Microscopic examination of the retrieved thrombi demonstrated red blood cells, fibrin, and partial endothelialization. The parallel Trevo stent retriever technique has the potential as rescue therapy for refractory large-vessel occlusion. However, complications arising from this technique remain uncertain. Further studies are needed to determine the effect of this technique in terms of recanalization and clinical safety.

Abstract TP41: Assessing The Relationship Between The Los Angeles Motor Scale And Computed Tomography Perfusion Parameters In Acute Ischemic Stroke Secondary To Large Vessel Occlusion

The Los Angeles Motor Scale (LAMS) is a rapid pre-hospital scale used to predict stroke severity. LAMS has also been shown to accurately predict large vessel occlusions (LVOs), however, to date there is no study exploring whether LAMS correlates with CT perfusion (CTP) parameters used to decide mechanical thrombectomy (MT) candidacy. The aim of this study is to elucidate the potential relationship between LAMS and these CTP parameters. We retrospectively reviewed patients with LVO between September 2019 and October 2021. Patients were included if they had available CTP data and neurologic exam on admission. LAMS was documented based on EMS exam or scored retrospectively based on admission neurologic exam. CTP data was processed by RAPID (IschemaView, Menlo Park, CA) with ischemic core volume (rCBF &lt; 30%), Tmax volume (Tmax &gt; 6 second delay), hypoperfusion index (HI), and CBV index. Spearman’s correlations were performed between LAMS and the aforementioned CTP parameters. Eighty-five patients were included, of which 11 had intracranial internal carotid artery (ICA) occlusions, 52 had M1 occlusions, and 22 had proximal M2 occlusions. Of all patients, 26 had LAMS of 0-3, and 59 had LAMS of 4-5. In all cases, LAMS was positively correlated with CBF &lt;30% (Correlation Coefficient (CC): 0.32, p &lt; 0.01), Tmax &gt; 6 s (CC:0.23, p&lt; 0.04), HI (CC:0.27, p &lt; 0.01), and negatively correlated with CBV index (CC:-0.24, p &lt; 0.05). These relationships between LAMS and CBF &lt; 30% and HI were more pronounced in M1 occlusions (CC:0.42, p&lt; 0.01; 0.34, p&lt; 0.01 respectively) and proximal M2 occlusions (CC:0.53, p&lt;0.01; 0.48, p&lt; 0.03 respectively). LAMS also correlated with Tmax &gt; 6 s in M1 occlusions (CC:0.42, p&lt; 0.01), and negatively correlated with CBV index in M2 occlusions (CC:-0.69, p&lt; 0.01). There was no significant correlation between LAMS and CTP parameters in intracranial ICA occlusions. Our results indicate that LAMS is positively correlated with estimated ischemic core, perfusion deficit, and HI, and negatively correlated with CBV index in patients with LVO. Vessel based analyses reveal stronger correlations with M1 and M2 occlusions. This is the first study showing that the LAMS may be correlated with estimated ischemic core and collateral status parameters in patients with LVO.

Acute intracranial internal carotid artery occlusion: Extension and location of the thrombus as an influencing factor in Computed Tomography angiography findings

PurposeAcute intracranial internal carotid artery (ICA) occlusion can mimic an extracranial affectation on Computed Tomography angiography (CTA). This fact could be explained by the extension of the thrombus in the ICA concerning its arterial branches. This study aims to determine how this factor may influence imaging findings. MethodsA retrospective study was conducted from a single-center database of patients undergoing mechanical thrombectomy due to ICA occlusion between October 2017 and March 2022 (n = 77). Patients with acute intracranial ICA occlusion were included (n = 29) and divided into two groups, according to ICA opacification on CTA: the discernible extracranial ICA or group D, and the pseudo-occlusion or group P. Patency of posterior communicating, anterior choroidal, and ophthalmic arteries on digital subtraction angiography were collected to determine thrombus extension. Sensitivity and specificity were calculated for CTA. ResultsSignificant differences were found in DSA between group P (n = 17) and group D (n = 12) in the frequency of patency of major artery branches: the presence of posterior communicating (PCOM) and anterior choroidal arteries (AChA) was observed in 2 patients in group P vs. 10 in group D (p < 0.001); whereas the patency of the ophthalmic artery (OA) was visualized in 10 patients in group P vs. 12 in group D, p = 0.023). For the diagnosis of isolated intracranial ICA occlusion, CTA had a sensitivity of 43.5% and a specificity of 97.2%. ConclusionsThe location and extent of the thrombus in the intracranial ICA concerning major artery branches may influence CTA findings.

Etiologic and prognostic value of external carotid artery thrombus detection during endovascular therapy for anterior circulation proximal occlusions.

An early understanding of stroke mechanism may improve treatment and outcome in patients presenting with large vessel occlusion stroke (LVOS) treated with mechanical thrombectomy (MT). We aimed to investigate whether spontaneous external carotid artery (ECA) embolism detection during MT is associated with stroke etiology and clinical outcome. We retrospectively reviewed our prospectively maintained institutional database including consecutive patients with anterior circulation LVOS treated with MT between January 2015 and August 2020. An ECA embolus was detected in 68 of 1298 patients (5.2%). The kappa coefficient for interobserver agreement was 0.89 (95% confidence interval [CI] 0.82-0.95). ECA embolism was significantly associated with intracranial internal carotid artery (ICA) occlusion (p< 0.001), cardioembolic etiology (p< 0.001) and a lower clot burden score (p< 0.001). Day-1 variation of National Institutes of Health Stroke Scale score (adjusted odds ratio [OR] -2.7, 95% CI -4.9 to 0.3; p= 0.021) and delta Alberta Stroke Program Early Computed Tomography Score (adjusted OR 0.9, 95% CI 0.2 to 1.5; p= 0.004) were worse among patients with ECA emboli. There was no significant difference in 90-day functional outcome between groups (adjusted OR 0.8, 95% CI 0.42 to 1.52; p= 0.50). In patients with anterior circulation LVOS treated with MT, ECA embolism was significantly associated with cardioembolic etiology, high thrombus burden and proximal intracranial ICA occlusions. This underexplored angiographic pattern might provide a valuable etiologic clue to the underlying cause of anterior circulation LVOS and may also help determine the appropriate revascularization strategy.

Importance of First Pass Reperfusion in Endovascular Stroke Care ‐ Insights From Thrombectomy and Aneurysm Registry (STAR)

Background Mechanical thrombectomy has become the first‐line treatment strategy for patients with large‐vessel occlusion strokes. Often &gt;1 thrombectomy maneuver is necessary to achieve reperfusion. A first‐pass (FP) effect with improved functional outcomes after mechanical thrombectomy has been described. Aim of the present study is to investigate the FP effect in a large, international, multicenter stroke database. Methods Patients who underwent mechanical thrombectomy for large‐vessel occlusion stroke in the anterior cerebral circulation between January 2014 and January 2021 and achieved complete reperfusion were identified from the STAR (Stroke Thrombectomy and Aneurysm Registry). We compared functional outcomes of patients with FP (defined as modified treatment in cerebral ischemia score 3 after a single thrombectomy maneuver) versus multiple‐pass complete reperfusion (defined as modified treatment in cerebral ischemia 3 after ≥1 thrombectomy maneuver). Results A total of 1481 patients with anterior circulation large‐vessel occlusion stroke and successful recanalization were included in the analysis. FP complete recanalization was achieved in 778 patients versus 703 patients with multiple‐pass complete reperfusion. Patients with FP complete recanalization had higher Alberta Stroke Programme Early CT [Computed Tomography] Score at baseline (9 [7–10] versus 8 [7–10]; P =0.002), were less likely to be men (47% versus 51%; P =0.078) and to have intracranial internal carotid artery occlusions (14% versus 27%), as well as more likely to have M1/M2 occlusions (86% versus 73%; P &lt;0.001), diabetes (28% versus 24%; P =0.076), and atrial fibrillation (37% versus 32%; P =0.064). FP complete recanalization (odds ratio [OR], 1.49; P =0.026), lower age (OR, 0.966; P &lt;0.010), lower prestroke modified Rankin scale score (OR, 0.601; P &lt;0.001), diabetes (OR, 0.612; P =0.014), and higher Alberta Stroke Programme Early CT Score (OR, 1.183; P &lt;0.001) were independent predictors of favorable functional outcome (defined as modified Rankin scale score ≤2). In a subgroup analysis, the effect of FP complete reperfusion on favorable outcome was only detectable in patients with M1 occlusions (OR, 1.667; P =0.045). Predictors for FP reperfusion success were lower National Institutes of Health Stroke Scale score at baseline (OR, 0.980; P =0.020) and M1 occlusions (OR, 1.990; P &lt;0.001). Conclusions This analysis of a large, multicenter stroke database confirms the importance of FP reperfusion in endovascular stroke care.

Assessment of Primary Collateral Grades Based on the Integrity of Willis' Circle: Predicting the Prognosis of Acute Intracranial Internal Carotid Artery Occlusion Before Thrombectomy

Endovascular mechanical thrombectomy (EVMT) has shown significant efficacy in improving neurological functions in patients with intracranial internal carotid artery occlusion (IICAO), but its clinical outcomes are variable. We examined the relationship between favorable clinical outcomes after EVMT in IICAO and a set of predictors. In this retrospective study, 189 patients with IICAO treated by EVMT at 3 centers from November 2015 to December 2020 were included and analyzed. Non-contrast computed tomography and computed tomography angiography were evaluated on admission. The morphology of IICAO was categorized into Ia, Ib, L, or T types, depending on the involvement of the posterior communicating artery origin, proximal anterior cerebral artery, and middle cerebral artery. The Willis' circle was categorized as integrated or compromised Willis' circle. In combination with the involvement of the IICAO and the integrity of Willis' circle, we used the primary collateral grade (PCG) to describe the presence of functional Willisian collaterals. Baseline data including demographics, characteristics, vascular risk factors, and initial National Institutes of Health Stroke Scale scores were collected. Hemorrhagic transformation was evaluated using the 24-hour non-contrast computed tomography after EVMT. Favorable outcomes based on modified Rankin scale, were defined as 0-2 at 90days. A total of 189 patients were included (median age, 69years; 126 male [66.7%]). 104 patients [55.0%] showed reperfusion after EVMT, but 72 patients [38.1%] achieved favorable outcomes at 90days. The mortality rate of type Ib was significantly higher than that with type Ia (χ2=14.21, P= 0.001). The outcome with different structure of Willis' circle was not statistically different between the 2 groups. A multivariate logistic regression analysis showed that IICAO T-type (odds ratio, 0.028 [95% confidence interval: 0.323-3.829], P= 0.042) and PCG 2 (odds ratio 9.427[95% confidence interval:1.863-47.698], P= 0.007) were predictors of favorable outcomes. Evaluation of PCG by determining the type of IICAO and the integrity of Willis' circle may serve as a valuable indicator for the prognosis and as an essential reference for screening patients before EVMT.

Higher number of stent-retriever thrombectomy passes significantly increases risk of mass effect, poor functional outcome, and mortality.

Endovascular treatment (EVT) is a widely proven method to treat patients diagnosed with intracranial large vessel occlusion (LVO). Through this method of treatment, it has been hypothesized that a lower number of thrombectomy passes is an indicator of higher rates of modified Thrombolysis in Cerebral Infarction 2B-3 (mTICI) reperfusion and favorable outcomes at 90-days defined as modified Rankin Scale 0-2 (mRS). Through the utilization of a prospectively collected endovascular database between 2012-2020, variables such as demographics, co-morbid conditions, intracerebral hemorrhage, mass effect, mortality rate, and good/poor outcomes regarding mTICI score and mRS assessment at 90-days were examined. The outcomes between patients receiving EVT who were treated with < 3 thrombectomy passes or ≥3 passes were compared. Out of 454 patients treated with mechanical thrombectomy of qualifying intracranial internal carotid artery (ICA) or middle cerebral artery occlusion, site of occlusion (ICA, ICA-T M1, and M2/M3), a total of 372 (81.9%) were treated with < 3 passes (average age 70.34 ± 13.75 years, 46.0% women), and 82 (18.1%) were treated with ≥3 passes (average age 70.30 ± 13.72 years, 48.8% women). Significantly higher rates of mass effect (p = 0.043), mRS score 3-6 (p = 0.029), mortality (p = 0.025), and poor reperfusion (p < 0.0001) were noted in patients treated with ≥3 passes. A higher number of thrombectomy passes, characterized as ≥3 in this study, was associated with significantly worsened patient outcome regarding mRS and mortality. Further research is required to determine whether the number of thrombectomy passes is an accurate predictor of treatment outcome.