Distal Embolization in Relation to Radiological Thrombus Characteristics, Treatment Details, and Functional Outcome

Endovascular thrombectomy first-pass reperfusion and ancillary device placement

BACKGROUND

Recent randomized trials have demonstrated the efficacy of mechanical thrombectomy in treating acute ischemic stroke, however, further research is required to optimize this technique. We aimed to evaluate the impact of guide catheter position and clot crossing on revascularization rates using A Direct Aspiration First Pass Technique (ADAPT).

METHODS

Data were collected between January 2018 and August 2019 as part of the Spanish ADAPT Registry on ACE catheters (SARA), a multicenter observational study assessing real-world thrombectomy outcomes. Demographic, clinical, and angiographic data were collected. Subgroup analyses assessed the relationship between guide catheter/microguidewire position and modified Trombolysis in Cerebral Infarction (mTICI) scores. First pass effect (FPE) was defined as mTICI 3 after single pass of the device.

RESULTS

From a total of 589 patients, 80.8% underwent frontline aspiration thrombectomy. The median score on the National Institutes of Health Stroke Scale (NIHSS) was 16.0. After adjusting for confounders, the likelihood of achieving FPE (adjusted Odds Ratio (aOR), 0.587; 95% confidence interval (CI), 0.38 to 0.92; p=0.0194) were higher among patients with more distal petrocavernous placement of guide catheter. The likelihood of achieving FPE (aOR, 0.592; 95% CI, 0.39 to 0.90; p=0.0138) and final angiogram complete reperfusion (aOR, 0.465; 95% CI, 0.30 to 0.73; p=0.0008) were higher among patients without microguidewire crossing the clot. No difference was noted for time from arterial puncture to reperfusion in any study group. At the 90-day follow-up, the mortality rate was 9.2% and 65.8% of patients across the entire study cohort were functionally independent (modified Rankin Scale (mRS) 0-2).

CONCLUSIONS

Petrocavernous guide catheter placement improved first-pass revascularization. Crossing the occlusion with a microguidewire lowered the likelihood of achieving FPE and complete reperfusion after final angiogram.

True first-pass effect in patients undergoing thrombectomy for acute large core strokes

OBJECTIVE

The impact of true first-pass effect (T-FPE, achieving substantial recanalization with extended thrombolysis in cerebral infarction; eTICI 3 after 1 thrombectomy) and outcomes on acute ischemic stroke (AIS) with large ischemic core remains uncertain. We aimed to study the association between T-FPE and outcomes in AIS patients with large core infarct through a real-world multicenter study.

METHODS

From a prospective multicentric registry, we collected the data of all consecutive acute stroke patients with a large ischemic core who underwent thrombectomy and compared the outcomes of patients who achieved T-FPE and those who did not. In addition, we compared the outcomes of patients with different numbers of thrombectomy pass to identify the effectiveness of T-FPE. Multivariate analysis was performed to determine the predictors of T-FPE. The primary outcome was good functional outcome (modified Rankin Scale score; mRS 0-3) at 90 days. Safety outcomes included a 90-day mortality and symptomatic intracerebral hemorrhage within 48 hours after thrombectomy.

RESULTS

Between November 2021 and February 2023, 447 eligible patients at 38 stroke centers were enrolled. Out of 447 thrombectomy patients, T-FPE was achieved in 102 individuals (22.8%). T-FPE was significantly associated with a higher proportion of good functional outcome (mRS 0-3 at 3 months, OR 2.221, 95% CI 1.418-3.479, p < 0.001) and lower mortality than non-T-FPE patients (31.4% vs. 45.5%, p = 0.012). The occlusion sites and lower DBP were strong predictors of T-FPE.

INTERPRETATION

T-FPE was associated with favorable outcomes at 90 days in AIS patients with a large ischemic core who underwent EVT.

Effect of incomplete reperfusion patterns on clinical outcome: insights from the ESCAPE-NA1 trial

BACKGROUND

Incomplete reperfusion (IR) after mechanical thrombectomy (MT) can be a consequence of residual occlusion, no-reflow phenomenon, or collateral counterpressure. Data on the impact of these phenomena on clinical outcome are limited.

METHODS

Patients from the ESCAPE-NA1 trial with IR (expanded Thrombolysis In Cerebral Infarction (eTICI) 2b) were compared with those with complete or near-complete reperfusion (eTICI 2c-3) on the final angiography run. Final runs were assessed for (a) an MT-accessible occlusion, or (b) a non-MT-accessible occlusion pattern. The primary clinical outcome was modified Rankin Scale (mRS) 0-2 at 90 days. Our imaging outcome was infarction in IR territory on follow-up imaging. Unadjusted and adjusted incidence rate ratios (aIRR) with 95% confidence intervals (95% CI) were obtained.

RESULTS

Of 1105 patients, 443 (40.1%) with IR and 506 (46.1%) with complete or near-complete reperfusion were included. An MT-accessible occlusion was identified in 147/443 patients (33.2%) and a non-MT-accessible occlusion in 296/443 (66.8%). As compared with patients with near-complete/complete reperfusion, patients with IR had significantly lower chances of achieving mRS 0-2 at 90 days (aIRR 0.82, 95% CI 0.74 to 0.91). Rates of mRS 0-2 were lower in the MT-accessible occlusion group as compared with the non-MT-accessible occlusion pattern group (aIRR 0.71, 95% CI 0.60 to 0.83, and aIRR 0.89, 95% CI 0.81 to 0.98, respectively). More patients with MT-accessible occlusion patterns developed infarcts in the non-reperfused territory as compared with patients with non-MT occlusion patterns (68.7% vs 46.3%).

CONCLUSION

IR was associated with worse clinical outcomes than near-complete/complete reperfusion. Two-thirds of our patients with IR had non-MT-accessible occlusion patterns which were associated with better clinical and imaging outcomes compared with those with MT-accessible occlusion patterns.

Comparison of Clinical and Radiological Outcomes Between Different (Balloon) Guide Catheter With and Without Inflated Balloon in Acute Ischemic Stroke Patients: A MaSQ-Registry Study

PURPOSE

Balloon guide catheters (BGCs) are used in endovascular treatment (EVT) for ischemic stroke. Previous literature did not distinguish between BGC use with and without inflated balloon. This study aims to compare outcomes between non-BCG and BGC use with and without inflated balloon during EVT.

METHODS

Patients who underwent EVT for anterior circulation ischemic stroke between September 2020 and February 2023 were analyzed. Patients were divided into three groups: non-BGC, BGC with inflated balloon, or BGC without inflated balloon. The primary outcome was the ordinal modified Rankin Scale (mRS) at 90-day follow-up. Secondary outcomes included expanded Thrombolysis In Cerebral Ischemia score (eTICI) and periprocedural complications. Regression analyses with BGC with inflated balloon as comparator were performed with adjustments. Subgroup analyses were conducted based on first-line thrombectomy technique.

RESULTS

Out of 511 patients, 428 patients were included. Compared to BCG with inflated balloon, the mRS at 90 days did not differ in the group without inflated balloon (adjusted common [ac]OR: 1.07, 95%CI 0.67-1.73) or non-BGC (acOR: 1.42, 95%CI 0.83-2.42). Compared to patients treated with a BGC with inflated balloon, those treated with BGC without inflated balloon had lower eTICI scores (acOR: 0.59, 95%CI 0.37-0.94), and patients treated with non-BGC had lower chances of periprocedural complications (aOR: 0.41, 95%CI 0.20-0.86).

CONCLUSIONS

This study shows no clinical differences in ischemic stroke patients treated with BGC with inflated balloon compared to non-BGC and BGC without inflated balloon, despite lower periprocedural complication rates in the non-BGC group and lower eTICI scores in the BGC without inflated balloon group.

LEVEL OF EVIDENCE

Level 3, non-controlled retrospective cohort study.

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.

Prognostic value of recanalization attempts in endovascular therapy for M2 segment middle cerebral artery occlusions

BACKGROUND

There is growing evidence suggesting efficacy of endovascular therapy for M2 occlusions of the middle cerebral artery. More than one recanalization attempt is often required to achieve successful reperfusion in M2 occlusions, associated with general concerns about the safety of multiple maneuvers in these medium vessel occlusions.

AIM

The aim of this study was to investigate the association between the number of recanalization attempts and functional outcomes in M2 occlusions in comparison with large vessel occlusions (LVO).

METHODS

Retrospective multicenter cohort study of patients who underwent endovascular therapy for primary M2 occlusions. Patients were enrolled in the German Stroke Registry at 1 of 25 comprehensive stroke centers between 2015 and 2021. The study cohort was subdivided into patients with unsuccessful reperfusion (mTICI 0-2a) and successful reperfusion (mTICI 2b-3) at first, second, third, fourth, or ⩾fifth recanalization attempt. Primary outcome was 90-day functional independence defined as modified Rankin Scale score of 0-2. Safety outcome was the occurrence of symptomatic intracranial hemorrhage. Internal carotid artery or M1 occlusions were defined as LVO and served as comparison group.

RESULTS

A total of 1078 patients with M2 occlusion were included. Successful reperfusion was observed in 87.1% and 90-day functional independence in 51.9%. The rate of functional independence decreased gradually with increasing number of recanalization attempts (p < 0.001). In both M2 occlusions and LVO, successful reperfusion within three attempts was associated with greater odds of functional independence, while success at ⩾fourth attempt was not. Patients with ⩾4 attempts exhibited higher rates of symptomatic intracranial hemorrhage in M2 occlusions (6.5% vs 2.7%, p = 0.02) and LVO (7.2% vs 3.5%, p < 0.001).

CONCLUSION

This study suggests a clinical benefit of successful reperfusion within three recanalization attempts in endovascular therapy for M2 occlusions, which was similar in LVO. Our findings reduce concerns about the risk-benefit ratio of multiple attempts in M2 medium vessel occlusions.

DATA ACCESS STATEMENT

The data that support the findings of this study are available on reasonable request after approval of the German Stroke Registry (GSR) steering committee.

CLINICAL TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov Identifier: NCT03356392.

Safety and efficacy of adjunctive intra-arterial antithrombotic therapy during endovascular thrombectomy for acute ischemic stroke: a systematic review and meta-analysis

BACKGROUND

Half of patients who achieve successful recanalization following endovascular thrombectomy (EVT) for acute ischemic stroke experience poor functional outcome. We aim to investigate whether the use of adjunctive intra-arterial antithrombotic therapy (AAT) during EVT is safe and efficacious compared with standard therapy (ST) of EVT with or without prior intravenous thrombolysis.

METHODS

Electronic databases were searched (PubMed/MEDLINE, Embase, Cochrane Library) from 2010 until October 2023. Data were pooled using a random-effects model and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Risk of bias was assessed using ROBINS-I and ROB-2. The primary outcome was functional independence (modified Rankin Scale (mRS) 0-2) at 3 months. Secondary outcomes were successful recanalization (modified Thrombolysis In Cerebral Infarction (TICI) 2b-3), symptomatic intracranial hemorrhage (sICH), and 90-day mortality.

RESULTS

41 randomized and non-randomized studies met the eligibility criteria. Overall, 15 316 patients were included; 3296 patients were treated with AAT during EVT and 12 020 were treated with ST alone. Compared with ST, patients treated with AAT demonstrated higher odds of functional independence (46.5% AAT vs 42.6% ST; OR 1.22, 95% CI 1.07 to 1.40, P=0.004, I2=48%) and a lower likelihood of 90-day mortality (OR 0.71, 95% CI 0.61 to 0.83, P<0.0001, I2=20%). The rates of sICH (OR 1.00, 95% CI 0.82 to 1.22,P=0.97, I2=13%) and successful recanalization (OR 1.09, 95% CI 0.84 to 1.42, P=0.52, I2=76%) were not significantly different.

CONCLUSION

The use of AAT during EVT may improve functional outcomes and reduce mortality rates compared with ST alone, without an increased risk of sICH. These findings should be interpreted with caution pending the results from ongoing phase III trials to establish the efficacy and safety of AAT during EVT.

Association Between Recanalization Attempts and Functional Outcome After Thrombectomy for Large Ischemic Stroke

BACKGROUND

Recently, 3 randomized controlled trials provided high-level evidence that patients with large ischemic stroke achieved better functional outcomes after endovascular therapy than with medical care alone. We aimed to investigate whether the clinical benefit of endovascular therapy is associated with the number of recanalization attempts in extensive baseline infarction.

METHODS

This retrospective multicenter study enrolled patients from the German Stroke Registry who underwent endovascular therapy for anterior circulation large vessel occlusion between 2015 and 2021. Large ischemic stroke was defined as an Alberta Stroke Program Early Computed Tomography Score of 3 to 5. The study cohort was divided into patients with unsuccessful reperfusion (Thrombolysis in Cerebral Infarction score, 0-2a) and successful reperfusion (Thrombolysis in Cerebral Infarction score, 2b/3) at attempts 1, 2, 3, or ≥4. The primary outcome was favorable functional outcome defined as modified Rankin Scale score of 0 to 3 at 90 days. Safety outcomes were symptomatic intracranial hemorrhage after 24 hours and death within 90 days. Multivariable logistic regression was used to identify independent determinants of primary and secondary outcomes.

RESULTS

A total of 348 patients met the inclusion criteria. Successful reperfusion was observed in 83.3% and favorable functional outcomes in 36.2%. Successful reperfusion at attempts 1 (adjusted odds ratio, 5.97 [95% CI, 1.71-24.43]; P=0.008) and 2 (adjusted odds ratio, 6.32 [95% CI, 1.73-26.92]; P=0.008) increased the odds of favorable functional outcome, whereas success at attempts 3 or ≥4 did not. Patients with >2 attempts showed higher rates of symptomatic intracranial hemorrhage (12.8% versus 6.5%; P=0.046). Successful reperfusion at any attempt lowered the odds of death compared with unsuccessful reperfusion.

CONCLUSIONS

In patients with large vessel occlusion and Alberta Stroke Program Early Computed Tomography Score of 3 to 5, the clinical benefit of endovascular therapy was linked to the number of recanalization attempts required for successful reperfusion. Our findings encourage to perform at least 2 recanalization attempts to seek for successful reperfusion in large ischemic strokes, while >2 attempts should follow a careful risk-benefit assessment in these highly affected patients.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT03356392.

Impact of vessel tortuosity and radiological thrombus characteristics on the choice of first-line thrombectomy strategy: Results from the ESCAPE-NA1 trial

INTRODUCTION

Despite improvements in device technology, only one-third of stroke patients undergoing endovascular thrombectomy (EVT) achieve first-pass effect (FPE). We investigated the effect of arterial tortuosity and thrombus characteristics on the relationship between first-line EVT strategy and angiographic outcomes.

PATIENTS AND METHODS

Patients with thin-slice baseline CT-angiography from the ESCAPE-NA1 trial (Efficacy and safety of nerinetide for the treatment of acute ischemic stroke) were included. Tortuosity was estimated using the tortuosity index extracted from catheter pathway, and radiological thrombus characteristics were length, non-contrast density, perviousness and hyperdense artery sign. We assessed the association of first-line EVT strategy (stent-retriever [SR] versus contact aspiration [CA] versus combined SR+CA) with FPE (eTICI score 2c/3 after one pass), final eTICI 2b/3, number of passes and procedure duration using multivariable regression. Interaction of tortuosity and thrombus characteristics with first-line technique were assessed using interaction terms.

RESULTS

Among 520 included patients, SR as a first-line modality was used in 165 (31.7%) patients, CA in 132 (25.4%), and combined SR+CA in 223 (42.9%). FPE was observed in 166 patients (31.9%). First-line strategy was not associated with FPE. Tortuosity had a significant effect on FPE only in the CA group (aOR = 0.90 [95% CI 0.83-0.98]) compared with stent-retrievers and combined first-line approach (p interaction = 0.03). There was an interaction between thrombus length and first-line strategy for number of passes (p interaction = 0.04). Longer thrombi were associated with higher number of passes only in the CA group (acOR 1.03 [95% CI 1.00-1.06]).

CONCLUSION

Our study suggests that vessel tortuosity and longer thrombi may negatively affect the performance of first-line contact aspiration catheters in acute stroke patients undergoing EVT.

Predictors of tissue infarction from distal emboli after mechanical thrombectomy

BACKGROUND

Distal embolization after endovascular thrombectomy (EVT) is common. We aimed to determine factors associated with tissue infarction in the territories of distal emboli.

METHODS

This is a retrospective cohort study of consecutive patients with anterior circulation large vessel occlusions who underwent EVT from 2015 to 2021. Patients with Thrombolysis In Cerebral Infarction (TICI) 2b reperfusion and follow-up imaging were identified. Baseline characteristics, procedural details, and imaging findings were reviewed. Primary outcome was categorized according to the occurrence of infarction at the territory of distal embolus on follow-up diffusion-weighted imaging MRI.

RESULTS

Of 156 subjects, 97 (62%) had at least one infarction in the territories at risk. Hypertension was significantly more prevalent in the infarct group (83% vs 53%, P=0.001). General anesthesia was more commonly used in the infarct group (60% vs 43%, P=0.037). The median number of distal emboli and diameter of the occluded vessel were similar. After adjusting for confounders, hypertension (aOR 4.73, 95% CI 1.81 to 13.25, P=0.002), higher blood glucose (aOR 1.01, 95% CI 1.00 to 1.03, P=0.023), and general anesthesia (aOR 2.75, 95% CI 1.15 to 6.84, P=0.025) were independently associated with infarction. The presence of angiographic leptomeningeal collaterals predicted tissue survival (aOR 0.13, 95% CI 0.05 to 0.33, P<0.001). 90-day modified Rankin scale (mRS) scores were worse for the infarction patients (mRS 0-2: infarct, 39% vs 55%, P=0.046).

CONCLUSIONS

Nearly 40% of patients with TICI 2b had no tissue infarction in the territory of a distal embolus. The association of infarction with hypertension and general anesthesia suggests late or post-procedural blood pressure management could be a modifiable factor. Patients with poor leptomeningeal collaterals or hyperglycemia may benefit from further attempts at revascularization.

Effect of proximal blood flow arrest during endovascular thrombectomy (ProFATE): Study protocol for a multicentre randomised controlled trial

BACKGROUND

Observational studies have demonstrated improved outcomes with the adjunctive use of balloon guide catheters (BGC) during endovascular thrombectomy (EVT) for anterior circulation acute ischaemic stroke (AIS). However, the lack of high-level evidence and global practice heterogeneity justifies a randomised controlled trial (RCT) to investigate the effect of transient proximal blood flow arrest on the procedural and clinical outcomes of patients with AIS following EVT.

HYPOTHESIS

Proximal blood flow arrest in the cervical internal carotid artery during EVT for proximal large vessel occlusion is superior to no flow arrest in achieving complete vessel recanalisation.

METHODS

ProFATE is an investigator-initiated, pragmatic, multicentre RCT with blinding of participants and outcome assessment. An estimated 124 participants with an anterior circulation AIS due to large vessel occlusion, an NIHSS of ⩾2, ASPECTS ⩾ 5 and eligible for EVT using a first-line combined technique (contact aspiration and stent retriever) or contact aspiration only will be randomised (1:1) to receive BGC balloon inflation or no inflation during EVT.

OUTCOMES

The primary outcome is the proportion of patients achieving near-complete/complete vessel recanalisation (eTICI 2c-3) at the end of the EVT procedure. Secondary outcomes include the functional outcome (modified Rankin Scale at 90 days), new or distal vascular territory clot embolisation rate, near-complete/complete recanalisation after the first pass, symptomatic intracranial haemorrhage, procedure-related complications and death at 90 days.

DISCUSSION

This is the first RCT to investigate the effect of proximal blood flow arrest during EVT using a BGC on the procedural and clinical outcomes of patients with AIS due to large vessel occlusion.