Significance of angiographic clot meniscus sign in mechanical thrombectomy of basilar artery stroke

"The microcatheter contrast injection technique": A novel technique to detect the proximal end of a thrombus in mechanical thrombectomy

Background: An aspiration catheter needs to attach to a thrombus in order to achieve first-pass recanalization by mechanical thrombectomy (MT) for acute ischemic stroke (AIS), particularly that using a direct aspiration first pass technique. The meniscus sign, which is defined as meniscoid contrast opacification indicating the proximal edge of a thrombus, has been suggested to contribute to successful recanalization. In some cases, the meniscus sign is not detected following an injection of contrast medium through a guiding catheter. To precisely identify the location of a thrombus, we use "the microcatheter contrast injection (MCI) technique," which accurately shows the proximal edge of a thrombus. We herein introduce this novel technique and discuss its efficacy in MT. Methods: In cases without the meniscus sign, a microcatheter was advanced to the distal end of contrast opacification, and contrast medium was injected through the microcatheter to detect the meniscus sign. An aspiration catheter was then advanced to the thrombus indicated by the meniscus sign and slowly withdrawn under aspiration. Results: 29 patients underwent MT for AIS using the MCI technique. Even in cases without the meniscus sign on initial angiography, the MCI technique accurately revealed the proximal edge of the thrombus. Moreover, middle cerebral artery occlusion due to atherosclerotic stenosis and displacement of the aspiration catheter and thrombus axis were detected using this technique. Conclusions: The MCI technique may effectively reveal the exact site of a thrombus and increase the success rate of first-pass recanalization.

Meniscus Sign in Patients with Anterior Circulation Large Vessel Occlusion Stroke does not Predict Outcome

PURPOSE

The angiographic appearance of the occlusion site was suggested to influence outcomes of stroke patients with large vessel occlusion (LVO) who undergo endovascular treatment (EVT). We aimed to study the impact of the meniscus sign (MS) on outcomes of stroke patients with anterior circulation LVO.

METHODS

Based on two prospective registries of acute ischemic stroke, we selected patients with carotid‑T, M1 or M2 occlusion who underwent EVT. Clinical characteristics and outcomes were collected from the registries or from individual records. Two independent observers blinded to outcomes assessed the presence of MS in digital subtraction angiography before thrombectomy. Angiographic and clinical outcomes of patients with and without MS were compared.

RESULTS

We included 903 patients, with median age of 78 years, 59.8% were male, median baseline NIHSS was 14 and 39.5% received intravenous thrombolysis. Patients with MS (n = 170, 18.8%) were more frequently female, presented with higher NIHSS scores and more frequently underwent intravenous thrombolysis. Presence of MS was significantly associated with cardioembolic etiology. Successful reperfusion, number of passes, first pass effect, procedural time, symptomatic intracerebral hemorrhage, in-hospital mortality and favorable 3‑month functional outcome were similar in the groups of patients with and without MS. In the multivariable analyses, MS was not associated with successful reperfusion (odds ratio, OR = 1.08, 95% confidence interval, CI = 0.76-1.55), first pass effect (OR = 0.96, 95%CI = 0.48-1.92) or favorable 3‑month outcome (OR = 1.40, 95%CI = 0.88-2.24).

CONCLUSION

The presence of MS in acute ischemic stroke patients with anterior circulation large vessel occlusion who undergo EVT does not appear to influence angiographic or clinical outcomes.

Predictors of first pass effect and effect on outcomes in mechanical thrombectomy for basilar artery occlusion

INTRODUCTION

For patients undergoing endovascular thrombectomy (EVT), those who are recanalized with a successful single pass (first pass effect, FPE) have better functional outcomes than those who do not. There is a scarcity of data regarding predictors of FPE in basilar artery occlusion (BAO). We aim to determine what characteristics may predict FPE for posterior circulation thrombectomies in a cohort of patients undergoing EVT for BAO.

METHODS

We reviewed prospectively-collected data for patients presenting to a comprehensive stroke center with BAO between December 2015 and April 2019. Patients were included in this study if they underwent manual aspiration thrombectomy for BAO. Patients were excluded if they had occlusions of the posterior cerebral or vertebral arteries or if they had tandem lesions. Patients were stratified by whether FPE or modified FPE (mFPE) was achieved, and multivariate logistic regression analyses were performed to identify predictors of FPE and the effect of FPE on clinical outcome.

RESULTS

100 patients with BAO underwent thrombectomy. Mean age was 64.7 ± 16.7, 42% were female, and median NIHSS was 20 (IQR 11-27). 33% met criteria for FPE and 60% for mFPE. Univariate analysis identified female gender, lack of IV-tPA use, pcASPECTS, atrial fibrillation, and hyperlipidemia as possible predictors of FPE. On multivariate analysis, age, pcASPECTs, atrial fibrillation, hyperlipidemia and IV-tPA use were not independent predictors of FPE or mFPE. Female gender was an independent predictor of mFPE (p = 0.02), but not FPE (p = 0.18). FPE was a predictor of mRS 0-2 at 90 days (p = 0.04). Predictors of mortality were age (p < 0.01), baseline NIHSS (p < 0.01) and mFPE (p = 0.01).

CONCLUSION

In this cohort analysis of 100 patients with basilar artery occlusion undergoing manual aspiration thrombectomy, female gender was associated with mFPE but not FPE. Previously-reported anterior circulation FPE predictors including age, ASPECTS and atrial fibrillation were not predictors of FPE in this cohort of patients with BAO.

Contrast agent retention sign in angiography predicts acute internal carotid artery embolic occlusion

BACKGROUND

Identification of acute internal carotid artery embolism (ICAE) and internal carotid artery atherosclerotic stenosis (ICAAS) in acute ischemic stroke patients is important for selection of treatment. The presence of contrast agent retention on pre-procedural angiographic images is more common in patients with ICA occlusion caused by embolism compared to patients with ICA atherosclerotic stenosis. This study aimed to evaluate effectiveness of contrast agent retention sign for predicting ICAE.

METHODS

Sixty-five patients with ICA occlusion who underwent emergency endovascular treatment from September 2014 to September 2020 were included in this retrospective analysis. Patients were divided into ICAE (n = 46) and ICAAS (n = 19) groups. Clinical characteristics, imaging data and ICA contrast agent retention signs of patients were collected. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnosis accuracy of contrast agent retention sign were conducted.

RESULTS

The positive ICA contrast agent retention sign was significantly more common in patients with ICAE (60.87% vs 0.00%, P < 0.001) than that of patients with ICAAS, but significantly lower in male patients (53.57% vs 81.08%, P = 0.017). There were significantly more patients with positive sign had occlusion in C6 segment (64.29% vs 13.51%, P < 0.001) and no outflow tract (85.71% vs 5.41%, P < 0.001) compared with negative sign group. There were significantly fewer patients with postive sign had occlusion in C1 segment (0.00% vs 40.54%, P < 0.001) compared with negative sign group. The sensitivity, specificity, PPV, NPV and diagnosis accuracy of contrast agent retention sign for predicting ICAE occlusion were 60.87%, 100%, 100%, 51.35% and 72.31%, respectively.

CONCLUSION

The ICA contrast agent retention sign has very high specificity and moderate sensitivity for detection of acute ICAE.

The claw sign predicts first-pass effect in mechanical thrombectomy for cerebral large vessel occlusion in the anterior circulation

Background:

Mechanical thrombectomy (MT) is an effective treatment for acute cerebral large vessel occlusion (LVO). Complete recanalization of vessels in a single procedure is defined as the first-pass effect (FPE) and is associated with good prognosis. In this study, angiographic clot protruding sign termed the “claw sign,” was examined as candidate preoperative imaging factor for predicting the FPE.

Methods:

We retrospectively analyzed data from 91 consecutive patients treated for acute LVO in the anterior circulation by MT between January 2014 and December 2019. The claw sign was defined as a thrombus that protruded proximally by more than half of the diameter of the parent artery. Radiological findings such as claw sign, clinical and etiological features, and outcomes were compared between groups with and without successful FPE. Multivariate analysis was conducted to evaluate perioperative factors associated with FPE.

Results:

FPE was achieved in 26 of 91 (28.6%) patients and the claw sign was observed in 34 of 91 (37.4%) patients. The claw sign was significantly more frequent in the successful FPE group than in the failed FPE group (53.8% vs. 30.8%; P = 0.040). After the multivariate analysis, the claw sign was the only pretreatment parameter that could predict FPE (odds ratio, 2.67; 95% confidence interval, 1.01–7.06; P = 0.047).

Conclusion:

The claw sign is an angiographic imaging factor that might predict FPE after MT for anterior circulation acute ischemic stroke.

Clot Meniscus Sign Is Associated With Thrombus Permeability and Choice of Mechanical Thrombectomy Technique in Acute Middle Cerebral Artery Occlusion

Background and Purpose

The method of mechanical thrombectomy (MT) is related to vascular anatomy and stroke etiology. Meniscus sign and thrombus permeability as imaging markers may be instructive for the selection of MT. This study aims to clarify the relationship among meniscus sign, thrombus permeability, and choice of MT in patients with acute middle cerebral artery occlusion.

Materials and Methods

A total of 111 patients with acute middle cerebral artery occlusion (MCAO) who underwent MT were retrospectively analyzed. Clot meniscus sign was defined as the appearance of meniscoid/edge-like or single- or double-wall contrast channels besides or around insular blood clots. The radiographic, clinical, and surgical data of patients with MCAO with or without meniscus sign were compared.

Results

The meniscus sign positive group (n = 26) has higher thrombus permeability (HUs) (26.92 ± 9.69 vs. 22.84 ± 7.88, p = 0.031) than those without it. Shorter puncture-to-recanalization (P2R) time (65.5 vs. 88, p = 0.012), higher complete recanalization rate (85.71 vs. 33.33%, p &lt; 0.01), and better clinical outcome (p &lt; 0.01) were obtained by selecting contact aspiration (CA) over stent retriever (SR) in patients with positive meniscus sign. In patients with negative meniscus sign, there was no significant difference in clinical outcome after receiving CA or SR.

Conclusion

Patients with MCAO with positive meniscus sign have higher thrombus permeability and are more suitable for CA to acquire better clinical outcomes.

Association of Stent-Retriever Characteristics in Establishing Successful Reperfusion During Mechanical Thrombectomy : Results from the ESCAPE-NA1 Trial

BACKGROUND

Successful reperfusion determines the treatment effect of endovascular thrombectomy. We evaluated stent-retriever characteristics and their relation to reperfusion in the ESCAPE-NA1 trial.

METHODS

Independent re-scoring of reperfusion grade for each attempt was conducted. The following characteristics were evaluated: stent-retriever length and diameter, thrombus position within stent-retriever, bypass effect, deployment in the superior or inferior MCA trunk, use of balloon guide catheter and distal access catheter. Primary outcome was successful reperfusion defined as expanded thrombolysis in cerebral infarction (eTICI) 2b-3 per attempt. The secondary outcome was successful reperfusion eTICI 2b-3 after the first attempt. Separate regression models for each stent-retriever characteristic and an exploratory multivariable modeling to test the impact of all characteristics on successful reperfusion were built.

RESULTS

Of 1105 patients in the trial, 809 with the stent-retriever use (1241 attempts) were included in the primary analysis. The stent-retriever was used as the first-line approach in 751 attempts. A successful attempt was associated with thrombus position within the proximal or middle third of the stent (OR 2.06; 95% CI: 1.24-3.40 and OR 1.92; 95% CI: 1.16-3.15 compared to the distal third respectively) and with bypass effect (OR 1.7; 95% CI: 1.07-2.72). Thrombus position within the proximal or middle third (OR 2.80; 95% CI: 1.47-5.35 and OR 2.05; 95% CI: 1.09-3.84, respectively) was associated with first-pass eTICI 2b-3 reperfusion. In the exploratory analysis accounting for all characteristics, bypass effect was the only independent predictor of eTICI 2b-3 reperfusion (OR 1.95; 95% CI: 1.10-3.46).

CONCLUSION

The presence of bypass effect and thrombus positioning within the proximal and middle third of the stent-retriever were strongly associated with successful reperfusion.

First Pass Effect With Neurothrombectomy for Acute Ischemic Stroke: Analysis of the Systematic Evaluation of Patients Treated With Stroke Devices for Acute Ischemic Stroke Registry

BACKGROUND AND PURPOSE

Achieving complete revascularization after a single pass of a mechanical thrombectomy device (first pass effect [FPE]) is associated with good clinical outcomes in patients with acute ischemic stroke due to large vessel occlusion. We assessed patient characteristics, outcomes, and predictors of FPE among a large real-world cohort of patients (Systematic Evaluation of Patients Treated with Stroke Devices for Acute Ischemic Stroke registry).

METHODS

Demographics, clinical outcomes, and procedural characteristics were analyzed among patients in whom FPE (modified Thrombolysis in Cerebral Infarction 2c/3 after first pass) was achieved versus those requiring multiple passes (MP). Modified FPE and modified MP included patients achieving modified Thrombolysis in Cerebral Infarction 2B-3. Primary outcomes included 90-day modified Rankin Scale (mRS) score and mortality.

RESULTS

Among 984 Systematic Evaluation of Patients Treated with Stroke Devices for Acute Ischemic Stroke patients, 930 had complete 90-day follow-up. FPE was achieved in 40.5% (377/930) of patients and MP in 20.0% (186/930). Baseline characteristics were similar across all groups. The FPE group had fewer internal carotid artery occlusions compared with MP (P=0.029). The FPE group had faster puncture to recanalization time (P≤0.001), higher rates of 90-day mRS score of 0 to 1 (52.6% versus 38.6%, P=0.003), mRS score of 0 to 2 (65.4% versus 52.0%, P=0.003), and lower 90-day mortality compared with the MP group (12.0% versus 18.7%, P=0.038). Similarly, compared with modified MP patients, the modified FPE group had fewer internal carotid artery occlusions (P=0.004), faster puncture to recanalization time (P≤0.001), and higher rates of 90-day mRS score of 0 to 1 (P=0.002) and mRS score of 0 to 2 (P=0.003).

CONCLUSIONS

Our findings demonstrate that FPE and modified FPE are associated with superior clinical outcomes.

Stent Opening Visualization During Mechanical Thrombectomy; Relationship with the Retrieved Clot and Procedural Success

PURPOSE

The angiographic visualization of the stent during mechanical thrombectomy (MT) may provide information regarding the characteristics of the underlying occluding clot, device-clot interaction, and recanalization. The purpose of this study was to evaluate the open stent sign in relation to the retrieved clot and recanalization.

METHODOLOGY

78 patients treated with the stent retriever for acute stroke were retrospectively reviewed. The open stent sign was defined as full opening (>80% of normal vessel diameter) of the stent on DSA after deployment across the occlusion. The retrieved clot was visually classified as red or non-red clots. The relationship between the open stent sign and the patient characteristics, recanalization, retrieved clot, and clinical outcome were analyzed.

RESULTS

Overall successful recanalization and good outcome was achieved in 68 (87.2%) and 35 (44.9%) patients, respectively. Open stent sign was seen in 52 patients (66.7%). Occlusions showing positive open stent sign was associated with significantly higher first pass effect (44.2% vs 19.2%, p=0.044) and successful recanalization rate (94.2% vs 73.1%, p=0.013) compared to negative open stent sign. The open stent sign was associated with higher incidence of red clot (75.0% vs 38.9%, p=0.008). On multivariate analysis, the open stent sign (OR 22.721, 95% CI 1.953-264.372, p=0.013) was a predictor of successful recanalization.

CONCLUSIONS

The visualization of the open stent during MT of acute ischemic stroke may provide added information in terms of clot characteristics and procedural success. The open stent sign is associated with red clots, higher first pass effect and successful recanalization.

Association of Regular Thrombus Surface Phenotype With Complete Recanalization in First-Line Contact Aspiration Thrombectomy for Basilar Artery Occlusion

Objective: To assess whether angiographic thrombus surface phenotype has an impact on efficacy of contact aspiration (CA) thrombectomy in patients with basilar artery occlusion (BAO). Methods: From January 2016 to December 2019, consecutive stroke patients with a BAO and first-line CA were analyzed in this retrospective study. We assessed baseline and imaging characteristics and treatment and clinical outcomes. We rated thrombus surface phenotype on pre-treatment digital subtraction angiography in a three-reader-consensus setting. Primary outcome was complete recanalization (modified treatment in cerebral ischemia [mTICI] 3 and arterial occlusive lesion [AOL] 3) after first-line CA without additionally stent retriever passes. Data analysis was stratified according to thrombus surface phenotype and complete first-line recanalization. Results: Seventy-eight patients met the inclusion criteria. Median age was 74 years (IQR 64-80), 64% were male, and median baseline NIHSS score was 24 (IQR 7-32). Thirty patients had a regular and 16 patients had an irregular thrombus phenotype. Thrombus surface was not assessable in 32 patients. In patients with a regular phenotype, complete recanalization was more often achieved compared to irregular and non-ratable phenotypes (50 vs. 18.8% and 21.9%; p = 0.027). Patients with a regular phenotype [odds ratio [OR] 8.3; 95% confidence interval [CI]: 1.9-35.8; p = 0.005], cardioembolic stroke (OR 12.1, 95% CI: 2.0-72.8; p = 0.007), and proximal end of the thrombus in the middle basilar artery segment (OR 5.2, 95% CI: 1.0-26.6; p = 0.046) were more likely to achieve complete recanalization after first-line CA without rescue therapy. Conclusion: The efficacy of CA may differ according to the angiographic thrombus surface phenotype in patients with BAO. A regular phenotype is associated with higher rates of complete recanalization in first-line CA. However, assessment of thrombus phenotype is frequently not feasible in BAO.

First-line contact aspiration versus first-line stent retriever for acute posterior circulation strokes: an updated meta-analysis

BACKGROUND

Both stent retriever (SR) and contact aspiration (CA) are widely used as first-line strategies for acute posterior circulation strokes (PCS). However, it is still unclear how CA and SR compare as the first-line treatment of acute PCS. Several new studies have been published recently, so we aimed to perform an updated meta-analysis.

METHODS

The meta-analysis was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) statement. Random-effects models were performed to pool the outcomes and the value of I² was calculated to assess the heterogeneity.

RESULTS

Ten observational studies with 1189 patients were included, among whom 492 received first-line CA and 697 received first-line SR. The pooled results revealed that first-line CA could achieve a significantly higher proportion of modified Thrombolysis In Cerebral Infarction (mTICI) 2b/3 (OR 1.90, 95% CI 1.33 to 2.71, I²=0%), mTICI 3 (OR 1.95, 95% CI 1.15 to 3.31, I²=59.6%), first-pass effect (OR 2.91, 95% CI 1.51 to 5.58, I²=0%), lower incidence of new-territory embolic events (OR 0.20, 95% CI 0.05 to 0.83, I²=0%), and shorter procedure time (mean difference -29.4 min, 95% CI -46.8 to -12.0 min, I²=62.8%) compared with first-line SR. At 90-day follow-up, patients subjected to first-line CA showed a higher functional independence (modified Rankin Scale score 0-2; OR 1.38, 95% CI 1.01 to 1.87, I²=23.5%) and a lower mortality (OR 0.71, 95% CI 0.50 to 1.00, p=0.050, I²=0%) than those subjected to first-line SR.

CONCLUSIONS

This meta-analysis suggests that the first-line CA strategy could achieve better recanalization and clinical outcomes for acute PCS than first-line SR. Limited by the quality of included studies, this conclusion should be drawn with caution.

Intraprocedural Angiographic Signs Observed During Endovascular Thrombectomy in Patients With Acute Ischemic Stroke: A Systematic Review

OBJECTIVE

In the real-world practice of endovascular thrombectomy (EVT) for acute ischemic stroke (AIS), the analysis of intraprocedural angiographic signs (IPASs) still challenges neurointerventionists. This review provides insights into the significance of these subtle changes for predicting underlying etiology, technical feasibility, and patient prognosis, thus promoting the potential real-time application of these signs.

METHODS

A systematic literature search was conducted using PubMed, Ovid Medline/Embase, and Cochrane. The search focused on studies published between January 1995 and August 2020 that reported findings related to intraprocedural angiographic manifestations in endovascular recanalization therapy for AIS.

RESULTS

We identified 12 IPASs in 22 studies involving 1,683 patients. The IPASs were assigned into 3 subsets according to their clinical meanings.

CONCLUSION

The systematic analysis of IPAS in clinical trials and practice will lead to a better understanding of treatment effects, responses, and mechanisms during EVT. Studies of larger cohorts using more robust statistical methods are needed.

Clot Meniscus Sign: An Angiographic Clue for Choosing between Stent Retriever and Contact Aspiration in Acute Basilar Artery Occlusion

BACKGROUND AND PURPOSE

The efficacy of mechanical thrombectomy methods may differ depending on the characteristics of the occlusion. The purpose of this study was to compare the recanalization efficacy and treatment outcome of a stent retriever versus contact aspiration in patients with acute basilar artery occlusion according to the angiographic characteristics of the occlusion.

MATERIALS AND METHODS

One hundred sixty-one patients with acute basilar artery occlusion who underwent mechanical thrombectomy were retrospectively analyzed. A stent retriever was compared with contact aspiration thrombectomy according to the clot meniscus sign, defined as a meniscoid/tram-track-like sidewall contrast opacification of the thrombus. A propensity score matching analysis was performed. Clinical/angiographic characteristics and treatment and clinical outcomes were compared.

RESULTS

Overall, a stent retriever (n = 118) and contact aspiration (n = 43) did not show significant differences in the successful recanalization (82.2% versus 86.0%) and good clinical outcome rates (32.2% versus 39.5%). In patients with the positive meniscus sign, contact aspiration was associated with shorter procedural time (44 versus 26 minutes, P = .018), a lower number of passes (2 versus 1, P = .041), a higher complete recanalization rate (58.8% versus 85.7%, P = .021), and a higher rate of first-pass effect (27.9% versus 53.6%, P = .031) compared with a stent retriever. After propensity score matching, contact aspiration was associated with higher complete recanalization rates (59.3% versus 85.7%, P = .033). No significant differences in the outcomes were noted between a stent retriever and contact aspiration in patients negative for the meniscus sign.

CONCLUSIONS

The efficacy of the mechanical thrombectomy techniques may differ according to the angiographic characteristics of occlusion in patients with basilar artery occlusion. Contact aspiration may be more effective in terms of recanalization compared with a stent retriever in patients with the clot meniscus sign.