Comparison of First-Pass Efficacy Among Four Mechanical Thrombectomy Techniques: A Single-Center Experience

Impact of double stent retriever configuration on first-pass effect in stroke: a multicenter study

BACKGROUND

Efficient recanalization of occluded cerebral arteries is crucial in the treatment of acute ischemic stroke. Double stent retrievers have shown the potential to enhance the rates of recanalization on the first pass. This study aims to evaluate the efficacy and safety of the double stent retriever technique and the predictors of achieving first-pass effect in patients with acute ischemic stroke.

METHODS

This prospective multicenter study involved 209 patients from 16 comprehensive stroke centers in Spain. Patients with occlusions in the anterior circulation were treated using the Aperio Hybrid double stent retriever. The study examined various deployment techniques, including simultaneous and sequential deployment and stent configurations, comparing the Y-shaped and parallel configurations.

RESULTS

The double stent retriever technique achieved a first-pass effect in 72.7% of cases and a final successful recanalization rate of 99.5%. The Y-shaped configuration was significantly associated with higher recanalization rates on the first pass (OR 2.59, 95% CI 1.18 to 5.68, P=0.02). Procedural complications were mild to moderate in 6.7% and severe in 1.5% of cases, with symptomatic intracranial hemorrhage occurring in 3.3% of patients. At 3 months follow-up, 57.2% of patients achieved a good clinical outcome, with a mortality rate of 15.1%.

CONCLUSION

The findings support the efficacy of the double stent retriever technique, particularly the Y-shaped configuration, in achieving high recanalization rates on the first pass with an acceptable safety profile. This technique may offer clinical benefits for future acute ischemic stroke treatment protocols.

Current Approaches and Methods to Understand Acute Ischemic Stroke Treatment Using Aspiration Thrombectomy

Acute ischemic stroke occurs when a blood clot occludes a cerebral artery. Mechanical interventions, primarily stent retrievers and aspiration thrombectomy, are used currently for removing the occluding clot and restoring blood flow. Aspiration involves using a long catheter to traverse the cerebral vasculature to reach the blood clot, followed by application of suction through the catheter bore. Aspiration is also used in conjunction with other techniques such as stent retrievers and balloon guide catheters. Despite the wide use of aspiration, our physical understanding of the process and the causes of the failure of aspiration to retrieve cerebral clots in certain scenarios is not well understood. Experimental and computational studies can help develop the capability to provide deeper insights into the procedure and enable development of new devices and more effective treatment methods. We recapitulate the aspiration-based thrombectomy techniques in clinical practice and provide a perspective of existing engineering methods for aspiration. We articulate the current knowledge gap in the understanding of aspiration and highlight possible directions for future engineering studies to bridge this gap, help clinical translation of engineering studies, and develop new patient-specific stroke therapy.

Comparison of Balloon Guide Catheters and Standard Guide Catheters for Acute Ischemic Stroke: An Updated Systematic Review and Meta-analysis

OBJECTIVE

The objective of this study was to update our 2021 systematic review and meta-analysis which reported that balloon guide catheters (BGC) are associated with superior clinical and angiographic outcomes compared to standard guide catheters for treatment of acute ischemic stroke.

METHODS

We conducted a systematic review of 7 electronic databases to identify literature published between January 2010 and September 2023 reporting BGC versus non-BGC approaches. Primary outcomes were final modified thrombolysis in cerebral infarction (mTICI) ≥2b, first-pass effect (mTICI ≥2c on first pass), and modified Rankin scale 0-2 at 90 days. The risk of bias was assessed using the Newcastle Ottawa Scale. A separate random effects model was fitted for each outcome. Subgroup analyses by first-line approach were conducted.

RESULTS

Twenty-four studies comprising 8583 patients were included (4948 BGC; 3635 non-BGC; 1561 BGC + Stent-retriever; 1297 non-BGC + Stent-retriever). Nine studies had low risk of bias, 3 were moderate risk, and 12 were high risk. Patients treated with BGCs had higher odds of achieving mTICI 2b/3, first-pass effect mTICI 2c/3, and modified Rankin scale 0-2 at 90 days (P < 0.001). The number of patients needed to treat in order to achieve one additional successful recanalization is 17. BGC + Stent-retriever was associated with higher odds of mTICI≥2b, 90-day modified Rankin scale 0-2, and reduced odds of 90-day mortality compared to non-BGC + Stent-retrievers. The main limitation was the absence of randomized trials.

CONCLUSIONS

These findings corroborate our previous results suggesting that MT using BGCs is associated with better safety and effectiveness outcomes for acute ischemic stroke, especially BGC + Stent-retrievers.

Devices and Techniques

This extensive review explores the intricacies of the three principal mechanical thrombectomy techniques: the stent retriever technique, contact aspiration technique, and a combined approach, and their application in managing acute ischemic stroke. Each technique operates uniquely on the thrombus, leading to differences in their efficacy. Factors including clot size, clot stiffness, vessel tortuosity, and the angle of interaction between the aspiration catheter and the clot significantly influence these differences. Clinical trials and meta-analyses have shown the overall equivalency of these techniques for the treatments of large vessel occlusion and distal medium vessel occlusions. However, there are nuanced differences that emerge under specific clinical circumstances, highlighting the absence of a one-size-fits-all strategy in acute ischemic stroke management. We emphasize the need for future investigations to elucidate these nuances further, aiming to refine procedural strategies and individualize patient care for optimal outcomes.

Mechanical thrombectomy with combined stent retriever and contact aspiration versus stent retriever alone for acute large vessel occlusion: data from ANGEL-ACT registry

BACKGROUND AND PURPOSE

An analysis of the ASTER 2 trial revealed similar final recanalisation levels and clinical outcomes in acute large vessel occlusion (LVO) stroke between stent retrieval (SR) alone as a first-line mechanical thrombectomy (MT) technique (SR alone first-line) and concomitant use of contact aspiration (CA) plus SR as a first-line MT technique (SR+CA first-line). The purpose of the present study was to compare the safety and efficacy of SR+CA first-line with those of SR alone first-line for patients with LVO in China.

METHODS

We conducted the present study by using the data from the ANGEL-ACT registry. We divided the selected patients into SR+CA first-line and SR alone first-line groups. We performed logistic regression and generalised linear models with adjustments to compare the angiographic and clinical outcomes, including successful/complete recanalisation after the first technique alone and all procedures, first-pass successful/complete recanalisation, number of passes, 90-day modified Rankin Scale, procedure duration, rescue treatment and intracranial haemorrhage within 24 hours.

RESULTS

Of the 1233 enrolled patients, 1069 (86.7%) received SR alone first-line, and 164 (13.3%) received SR+CA first-line. SR+CA first-line was associated with more thrombectomy passes (3 (2-4) vs 2 (1-2); β=1.77, 95% CI=1.55 to 1.99, p<0.001), and longer procedure duration (86 (60-129) min vs 80 (50-122) min; β=10.76, 95% CI=1.08 to 20.43, p=0.029) than SR alone first-line group. Other outcomes were comparable (all p>0.05) between the two groups.

CONCLUSIONS

Patients undergoing SR+CA first-line had more thrombectomy passes and longer procedure duration than patients undergoing SR alone first-line. Additionally, we suggested that SR+CA first-line was not superior to SR alone first-line in final recanalisation level, first-pass recanalisation level and 90-day clinical outcomes in the Chinese population.

A review of mechanical thrombectomy techniques for acute ischemic stroke

Mechanical thrombectomy is established as standard of care in the management of acute ischemic stroke due to large vessel occlusion and evidence-based guidelines for mechanical thrombectomy have been defined. As research continues to further expand the eligibility criteria for thrombectomy and the number of thrombectomy procedures increase worldwide, there is also growing focus on innovation of thrombectomy devices, procedural techniques, and related outcomes. Thrombectomy primarily involves use of stent retrievers and distal aspiration techniques, but variations and different combinations of techniques have been reported. As this is a rapidly evolving area in stroke management, there is debate as to which, if any, of these techniques leads to improved clinical outcomes over another and there is a lack of data comparing them. In this review, currently published and distinct techniques of mechanical thrombectomy are described methodically along with illustrations to aid in understanding the subtle differences between the techniques. The perceived benefits of each variation are discussed.

Predictors and outcomes of first pass efficacy in posterior circulation strokes: Insights from STAR collaboration

Background: First-pass efficacy (FPE) has been established as an important predictor of favorable functional outcomes after endovascular thrombectomy (ET) in anterior circulation strokes. In this retrospective cohort study, we investigate predictors and clinical outcomes of FPE in posterior circulation strokes (pcAIS). Methods: The Stroke Thrombectomy and Aneurysm Registry database was used to identify pcAIS patients who achieved FPE. Their baseline characteristics and outcomes were compared with the non-FPE group. The primary outcome was a 90-day modified Rankin Scale (mRS) of 0-3. Univariate (UVA) and multivariate (MVA) analyses were done to evaluate predictors of FPE. Safety outcomes included distal emboli, vessel rupture, symptomatic intracranial hemorrhage, and mortality. Results: Of 359 patients, 179 (50%) achieved FPE. Clot burden, occlusion site, and ET technique-related variables were similar between the two groups except for shorter procedure time with FPE. The primary outcome was significantly better with FPE (56.4% vs. 32.8%, p < 0.001). Complications were similar except for a higher rate of distal emboli in non-FPE group (11.1% vs. 3.2%, p = 0.032). Atrial fibrillation (Afib) had increased odds (aOR: 2.06, 95% CI; 1.24, 3.4, p = 0.005) and prior ischemic stroke had decreased odds (aOR: 0.524, 95% CI; 0.28, 0.97, p = 0.04) of FPE. Afib was the only independent predictor of FPE on MVA (1.94, 95% CI; 1.1, 3.43, p = 0.022). Conclusions: Higher rate of FPE in Afib-related pcAIS could possibly be explained by the differences in clot composition and degree of in-situ atherosclerotic disease burden. Future studies are warranted to explore the relationship of clot composition with ET outcomes.

Patient and procedure selection for mechanical thrombectomy: Toward personalized medicine and the role of artificial intelligence

Mechanical thrombectomy (MT) for ischemic stroke due to large vessel occlusion is standard of care. Evidence-based guidelines on eligibility for MT have been outlined and evidence to extend the treatment benefit to more patients, particularly those at the extreme ends of a stroke clinical severity spectrum, is currently awaited. As patient selection continues to be explored, there is growing focus on procedure selection including the tools and techniques of thrombectomy and associated outcomes. Artificial intelligence (AI) has been instrumental in the area of patient selection for MT with a role in diagnosis and delivery of acute stroke care. Machine learning algorithms have been developed to detect cerebral ischemia and early infarct core, presence of large vessel occlusion, and perfusion deficit in acute ischemic stroke. Several available deep learning AI applications provide ready visualization and interpretation of cervical and cerebral arteries. Further enhancement of AI techniques to potentially include automated vessel probe tools in suspected large vessel occlusions is proposed. Value of AI may be extended to assist in procedure selection including both the tools and technique of thrombectomy. Delivering personalized medicine is the wave of the future and tailoring the MT treatment to a stroke patient is in line with this trend.

Poor clinical outcome despite successful basilar occlusion recanalization in the early time window: incidence and predictors

Background

Endovascular treatment (EVT) for basilar artery occlusions (BAO) is associated with a higher rate of futile recanalization compared with anterior circulation procedures. We aimed to identify the incidence and predictors of poor clinical outcome despite successful reperfusion in current clinical practice.

Methods

We used data from the ETIS (Endovascular Treatment in Ischemic Stroke) registry, a prospective multicenter observational registry of stroke treated with EVT in France. Patients undergoing EVT for acute BAO from January 2014 to May 2019 successfully treated within 8 hours from onset were included. Predictors of 90-day poor outcome (modified Rankin Scale (mRS) 4–6) were researched within patients with successful (modified Thrombolysis In Cerebral Infarction (mTICI 2b-3)) and excellent (mTICI 2c-3) reperfusion.

Results

Among 242 patients treated within 8 hours, successful reperfusion was achieved in 195 (80.5%) and excellent reperfusion in 120 (49.5%). Poor outcome was observed in 107 (54.8%) and 60 (50%) patients, respectively. In patients with successful early reperfusion, age, higher initial National Institutes of Health Stroke Scale (NIHSS) score, lower posterior circulation Alberta Stroke Programme Early CT Score (pc-ASPECTS), and absence of prior intravenous thrombolysis were independent predictors of poor outcome. The only treatment factor with an independent predictive value was first-pass mTICI 2b-3 reperfusion (adjusted OR 0.13, 95% CI 0.05 to 0.37, p<0.001). In patients with excellent early reperfusion, independent predictors were age, initial NIHSS score, first-pass mTICI 2c-3 reperfusion, and hemorrhagic transformation on post-interventional imaging.

Conclusions

Early successful reperfusion with EVT occurred in 80.5% of patients, and the only treatment-related factor predictive of clinical outcome was first pass mTICI 2b-3 reperfusion. Further research is warranted to identify the optimal techniques and devices associated with first pass reperfusion in the posterior circulation.

A Meta-analysis of Combined Aspiration Catheter and Stent Retriever versus Stent Retriever Alone for Large-Vessel Occlusion Ischemic Stroke

BACKGROUND

The efficacy of combined aspiration catheter and stent retriever compared with stent retriever alone for the treatment of large-vessel occlusion acute ischemic stroke is unclear.

PURPOSE

Our aim was to conduct a systematic literature review and meta-analysis on several metrics of efficacy comparing aspiration catheter and stent retriever with stent retriever alone.

DATA SOURCES

MEDLINE and the Cochrane Library Databases were searched. Randomized controlled trials and case-control and cohort studies were included.

STUDY SELECTION

Ten comparative studies were included detailing a combined 1495 patients with aspiration catheter and stent retriever and 1864 with stent retrievers alone.

DATA ANALYSIS

Data on first pass effect (TICI 2b/2c/3 after first pass), final successful reperfusion (modified TICI ≥2b), and 90-day functional independence (mRS ≤ 2) were collected. Meta-analysis was performed using a random-effects model.

DATA SYNTHESIS

There was a pooled composite first pass effect of 40.8% (611/1495) versus 32.6% (608/1864) for aspiration catheter and stent retriever and stent retriever alone, respectively (P < .0001). Similarly, on a meta-analysis, aspiration catheter and stent retriever were associated with a higher first pass effect compared with stent retriever alone (OR = 1.63; 95% CI, 1.20-2.21; P = .002; I² = 72%). There was no significant difference in composite rates of successful reperfusion between aspiration catheter and stent retriever (72.8%, 867/1190) and stent retriever alone (70.8%, 931/1314) (P = .27) or on meta-analysis (OR = 1.31; CI, 0.81-2.12; P = .27; I² = 82%). No difference was found between aspiration catheter and stent retriever and stent retriever alone on 90-day functional independence (OR = 1.02; 95% CI, 0.77-1.36; P = .88; I² = 40%).

LIMITATIONS

This study is limited by high interstudy heterogeneity.

CONCLUSIONS

On meta-analysis, aspiration catheter and stent retriever are associated with a superior first pass effect compared with stent retriever alone, but they are not associated with statistically different final reperfusion or functional independence.

Efficacy of combined use of a stent retriever and aspiration catheter in mechanical thrombectomy for acute ischemic stroke

BACKGROUND

The efficacy of combined stent retriever (SR) and aspiration catheter (AC; combined technique: CBT) use for acute ischemic stroke (AIS) is unclear. We investigated the safety and efficacy of single-unit CBT (SCBT)-retrieving the thrombus as a single unit with SR and AC into the guide catheter-compared with single use of either SR or contact aspiration (CA).

METHODS

We analysed 763 consecutive patients who underwent mechanical thrombectomy for AIS between January 2013 and January 2020, at six comprehensive stroke centers. Patients were divided into SCBT and single device (SR/CA) groups. The successful recanalization with first pass (SRFP) and other procedural outcomes were compared between groups.

RESULTS

Overall, 240 SCBT and 301 SR/CA (SR 128, CA 173) patients were analyzed. SRFP (modified Thrombolysis In Cerebral Infarction (mTICI) ≥2c, 43.3% vs 27.9%, p<0.001; mTICI 3, 35.8% vs 25.5%, p=0.009) and final mTICI ≥2b recanalization (89.1% vs 82.0%, p=0.020) rates were significantly higher, puncture-to-reperfusion time was shorter (median (IQR) 43 (31.5-69) vs 55 (38-82.2) min, p<0.001), and the number of passes were fewer (mean±SD 1.72±0.92 vs 1.99±1.01, p<0.001) in the SCBT group. Procedural complications were similar between the groups. In subgroup analysis, SCBT was more effective in women, cardioembolic stroke patients, and internal carotid artery and M2 occlusions.

CONCLUSIONS

SCBT increases the SRFP rate and shortens the puncture-to-reperfusion time without increasing procedural complications.

Clinical and Procedural Outcomes with or without Balloon Guide Catheters during Endovascular Thrombectomy in Acute Ischemic Stroke: A Systematic Review and Meta-analysis with First-line Technique Subgroup Analysis

BACKGROUND

Balloon guide catheters are increasingly used to improve clot retrieval by temporarily stopping proximal blood flow during endovascular thrombectomy.

PURPOSE

Our aim was to provide a summary of the literature comparing the procedural and clinical outcomes of endovascular thrombectomy with or without balloon guide catheters, depending on the first-line technique used.

DATA SOURCES

We used PubMed/MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews.

STUDY SELECTION

We chose studies that compared using balloon guide catheters with not using them.

DATA ANALYSIS

Random effects meta-analysis was performed to compare the procedural outcomes measured as the first-pass effect, successful reperfusion, number of passes, procedural duration, arterial puncture to reperfusion time, distal emboli, and clinical outcomes.

DATA SYNTHESIS

Overall, a meta-analysis of 16 studies (5507 patients, 50.8% treated with balloon guide catheters and 49.2% without them) shows that the use of balloon guide catheters increases the odds of achieving a first-pass effect (OR = 1.92; 95% CI, 1.34-2.76; P < .001), successful reperfusion (OR = 1.85; 95% CI, 1.42-2.40; P < .001), and good functional outcome (OR =1.48; 95% CI, 1.27-1.73; P < .001). Balloon guide catheters reduce the number of passes (mean difference = -0.35; 95% CI, -0.65 to -0.04; P = .02), procedural time (mean difference = -19.73; 95% CI, -34.63 to -4.83; P = .009), incidence of distal or new territory emboli (OR = 0.5; 95% CI, 0.26-0.98; P = .04), and mortality (OR = 0.72; 95% CI, 0.62-0.85; P < .001). Similar benefits of balloon guide catheters are observed when the first-line technique was a stent retriever or contact aspiration, but not for a combined approach.

LIMITATIONS

The analysis was based on nonrandomized trials with a moderate risk of bias.

CONCLUSIONS

Current literature suggests improved clinical and procedural outcomes associated with the use of balloon guide catheters during endovascular thrombectomy, especially when using the first-line stent retriever.