Increased Rate of Successful First Passage Recanalization During Mechanical Thrombectomy for M2 Occlusion

Efficacy and safety of combined stent retriever and contact aspiration vs. stent retriever alone on revascularization in patients with acute ischemic stroke: a systematic review and meta-analysis

Objective

Whether the efficacy of combined stent retriever and contact aspiration (S + A) is superior to stent retriever (S) alone for revascularisation in patients with large vessel occlusive stroke remains uncertain. The aim of this meta-analysis was to assess the safety and efficacy of combined stent retriever and contact aspiration for the treatment of acute ischaemic stroke with large vessel occlusion by comparing it with stent retriever alone.

Methods

We systematically searched the PubMed, Embase, Web of Science, and The Cochrane Library databases for randomised controlled trials and observational studies (case-control and cohort studies) published before 1 October 2023 comparing the efficacy of combined stent retriever and contact aspiration versus tent retriever alone in patients with large vessel occlusive stroke. The end point of the primary efficacy observed in this meta-analysis study was the rate of first pass nearly complete or complete recanalisation (mTICI 2c-3). Secondary effectiveness nodes were: rate of first pass successful recanalisation (mTICI 2b-3), rate of near-complete or complete recanalisation of the postoperative vessel, rate of successful recanalisation of the postoperative vessel, and MRS 0-2 within 90 days. Safety endpoints were interoperative embolism, symptomatic intracranial haemorrhage, and mortality within 90 days.

Results

A total of 16 studies were included in the literature for this meta-analysis, with a total of 7,320 patients (S + C group: 3,406, S group: 3,914). A comprehensive analysis of the included literature showed that combined stent retriever and contact aspiration had a higher rate of near-complete or complete recanalisation of the postoperative vessel [OR = 1.53, 95% CI (1.24, 1.88), p < 0.0001] and rate of successful recanalisation of the postoperative vessel compared to stent retriever alone [OR = 1.83, 95% CI (1.55, 2.17), p < 0.00001]; there were no statistically significant differences between the two groups in terms of the rate of first pass nearly complete or complete recanalisation [OR = 1.00, 95% CI (0.83, 1.19), p = 0.96], rate of first pass successful recanalisation [OR = 1.02, 95% CI (0.85, 1.24), p = 0.81], interoperative embolism [OR = 0.93, 95% CI (0.72, 1.20), p = 0.56], symptomatic intracranial haemorrhage [OR = 1.14, 95% CI (0.87, 1.48), p = 0.33], MRS 0-2 within 90 days [OR = 0.89, 95% CI (0.76, 1.04), p = 0.14] and mortality within 90 days [OR = 1.11, 95% CI (0.94, 1.31), p = 0.22].

Conclusion

Combined stent retriever and contact aspiration has a higher rate of postprocedural revascularisation (mTICI 2c-3/mTICI 2b-3) compared with stent retriever alone in patients with large vessel occlusion stroke. In addition, it was not superior to stenting alone in terms of the rate of first pass recanalisation (mTICI 2c-3/mTICI 2b-3), interoperative embolisation, symptomatic intracranial haemorrhage, good functional prognosis within 90 days and mortality within 90 days.

Mechanical thrombectomy for middle cerebral artery M2 occlusions

BACKGROUND

The safety and efficacy of mechanical thrombectomy (MT) for proximal large vessel occlusion after acute ischemic stroke (AIS) have been demonstrated. Clinical investigations of endovascular approaches for treating AIS due to M2 occlusions have been ongoing.

PURPOSE

To assess the outcomes of M2 occlusions according to treatment modality and anatomical division.

METHODS

A total of 113 consecutive M2 occlusions treated with endovascular treatment (EVT) at our tertiary stroke center between January 2019 and December 2022 were retrospectively analyzed. Patients were divided into three groups: mechanical thrombectomy (MT); intravenous thrombolysis plus MT (IVT + MT); and IVT alone. The primary outcomes were good prognosis (mRS = 0-2) and mortality (mRS = 6) on day 90. The secondary outcome was to determine the differences in outcomes between lesions in the superior and inferior branches of M2.

RESULTS

In total, 55 (48.7%) patients underwent MT. In 42 (37.2%) patients, bridging IVT was performed with MT, and IVT alone was applied in 16 (14.2%) patients. Neither the prognosis at 90 days nor the mortality rate significantly differed among the groups. The outcomes did not significantly differ between occlusions in the superior and inferior branches of M2.

CONCLUSION

MT was found to be safe and effective for treating M2 occlusions in this series.

First pass effect as an independent predictor of functional outcomes in medium vessel occlusions: An analysis of an international multicenter study

INTRODUCTION

First pass effect (FPE), achievement of complete recanalization (mTICI 2c/3) with a single pass, is a significant predictor of favorable outcomes for endovascular treatment (EVT) in large vessel occlusion stroke (LVO). However, data concerning the impact on functional outcomes and predictors of FPE in medium vessel occlusions (MeVO) are scarce.

PATIENTS AND METHODS

We conducted an international retrospective study on MeVO cases. Multivariable logistic modeling was used to establish independent predictors of FPE. Clinical and safety outcomes were compared between the two study groups (FPE vs non-FPE) using logistic regression models. Good outcome was defined as modified Rankin Scale 0-2 at 3 months.

RESULTS

Eight hundred thirty-six patients with a final mTICI ⩾ 2b were included in this analysis. FPE was observed in 302 patients (36.1%). In multivariable analysis, hypertension (aOR 1.55, 95% CI 1.10-2.20) and lower baseline NIHSS score (aOR 0.95, 95% CI 0.93-0.97) were independently associated with an FPE. Good outcomes were more common in the FPE versus non-FPE group (72.8% vs 52.8%), and FPE was independently associated with favorable outcome (aOR 2.20, 95% CI 1.59-3.05). 90-day mortality and intracranial hemorrhage (ICH) were significantly lower in the FPE group, 0.43 (95% CI, 0.25-0.72) and 0.55 (95% CI, 0.39-0.77), respectively.

CONCLUSION

Over 2/3 of patients with MeVOs and FPE in our cohort had a favorable outcome at 90 days. FPE is independently associated with favorable outcomes, it may reduce the risk of any intracranial hemorrhage, and 3-month mortality.

Modification by an aspiration catheter for vessel stretching in thrombectomy using a stent retriever in vitro

OBJECTIVES

Post-thrombectomy subarachnoid hemorrhage, which is caused by vessel stretching when retrieving a stent retriever (SR), is a complication of endovascular mechanical thrombectomy (EVT) using an SR. This in vitro study examined the association between EVT for middle cerebral artery (MCA) occlusion and M2 vessel stretching depending on the positioning of the SR or combined use of SR and aspiration catheter (AC) technique (CBT).

MATERIALS AND METHODS

A silicone vascular model was used. The maximum migration distance (MMD) in the anteroposterior view of an X-ray impermeable metal marker located at an M2 trunk 20 mm distal to the M1-2 bifurcation in angiographic images during an SR retrieval was calculated. According to the positioning of SR deployment (distal or proximal) and use of an AC [SR alone without an AC (SR alone) group, stent retrieval into an AC (SA) group, and stent-AC retrieval as a unit into a guiding catheter (SA unit) group], 60 attempts were conducted with each group of 10 attempts.

RESULTS

In distal SR deployment, the MMD in the CBT group, consisting of SA and SA unit groups, was significantly smaller than the SR alone group (1.36 ± 0.32 mm VS 2.39 ± 1.10 mm; p = 0.001). In proximal SR deployment, the CBT group showed a tendency to decrease MMD (1.38 ± 0.33 mm VS 1.63 ± 0.28 mm; p = 0.077).

CONCLUSIONS

This in vitro study showed that CBT might help modify the stretching of M2 when an SR is distally deployed in MCA occlusion.

Possible Contribution of the Aspiration Catheter in Preventing Post-stent Retriever Thrombectomy Subarachnoid Hemorrhage

PURPOSE

This study aimed to identify factors related to the incidence of post-thrombectomy subarachnoid hemorrhage (PTSAH).

METHODS

This retrospective, observational cohort study enrolled consecutive patients with acute ischemic stroke (AIS) due to the internal carotid artery (IC) top or middle cerebral artery (MCA) M1 or M2 segment occlusion who underwent single-pass stent retriever (SR) treatment between January 2015 and May 2022 at two acute care hospitals.

RESULTS

Of the 54 included patients, 10 were in the PTSAH group (18.5%). The occlusion sites were IC top (31.5%), M1 segment (48.1%), and M2 segment (20.4%). Aspiration catheters (ACs) were used in 32 (59.3%) patients; however, the combined technique (AC advancement at least to the most proximal marker of SR) was actually used in 26 (48.1%) patients because a ledge effect at the ophthalmic artery origin from the IC interfered with distal navigation of the ACs. The baseline patient characteristics did not differ between the groups. M2 segment occlusion in the PTSAH and non-PTSAH groups were 40.0% and 15.9%, respectively (p = 0.19). More ACs were used in the non-PTSAH group (65.9% vs. 30.0%, p = 0.07). Significantly fewer combined techniques were performed in the PTSAH group (10.0% vs. 56.8%, p = 0.01). In multivariate analysis adjusted by variables with M2 segment occlusion and the combined technique, the combined technique (odds ratio 0.098; 95% confidence interval, 0.011-0.887; p = 0.039) was identified as a significantly associated factor for PTSAH. There was one PTSAH case (1.9%) with symptom worsening.

CONCLUSION

The combined technique significantly influenced PTSAH occurrence as a preventive factor.

First-Pass Effect Predicts Clinical Outcome and Infarct Growth After Thrombectomy for Distal Medium Vessel Occlusions

BACKGROUND

The first-pass effect in endovascular thrombectomy (EVT) has been associated with better clinical outcomes and decreased stroke progression in large vessel occlusion but has not been evaluated in distal, medium vessel occlusions (DMVOs).

OBJECTIVE

To assess the impact on clinical outcome and stroke progression of the modified first-pass effect (defined as a successful first-pass [modified Thrombolysis In Cerebral Infarction 2b/2c/3] revascularization) in patients who underwent EVT for a primary DMVOs.

METHODS

We collected data from consecutive patients who underwent EVT for a primary DMVO at a single large academic center. We compared the rate of good clinical outcome (modified Rankin Scale of 0-2 at 3 months) and stroke progression between patients who demonstrated modified first-pass effect (mFPE) vs those who did not (no-mFPE).

RESULTS

Between January 2018 and January 2021, we included 60 patients who underwent EVT for an acute ischemic stroke with a primary DMVO. Overall, mFPE was achieved in 32% (19/60) of EVTs. The mFPE was associated with a higher rate of good clinical outcome compared with no-mFPE (89% vs 46%, odds ratio = 16.04 [2.23-115.39], P = .006 in multivariate analysis). Final stroke volume was less among mFPE patients (6.9 mL [4.7-13.6] vs 23 mL [14.6-47], P = .001) as was stroke progression (6.8 mL [4-12.1] vs 17.8 mL [8.1-34.9], P = .016). The mFPE was still associated with higher rates of good clinical outcome when compared with patients reaching an modified Thrombolysis In Cerebral Infarction score ≥2b in more than 1 pass (89% vs 53%; odds ratio = 7.37 [1.43-38.08], P = .017).

CONCLUSION

The mFPE may be associated with better clinical outcomes and lower stroke progression in DMVO.

Mechanical Thrombectomy for M2 Segment Occlusion in Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

BACKGROUND

The safety and benefit of mechanical thrombectomy (MT) in the treatment of acute ischemic stroke (AIS) patients with M2 segment middle cerebral artery occlusions remain uncertain.

OBJECTIVE

To investigate the benefit of mechanical thrombectomy for M2 occlusion compared with M1 occlusion in patients with AIS.

METHODS

The PubMed, Embase, and Cochrane Library databases were searched from inception to April 2021 to identify relevant articles. The main results comprised 90-day functional independence (modified Rankin Score from 0-2), successful recanalization (thrombectomy in cerebral infarction [TICI] 2b/3), mortality, and rates of symptomatic intracerebral hemorrhage after using modern thrombectomy devices. Odds ratios (ORs) were generated for binary variants. ReviewManager 5.3 software was used.

RESULTS

Ultimately, a total of 14 trials were included, with 3454 participants enrolled. MT for M2 occlusion had a higher rate of 3-month functional independence than M1 occlusion, but the difference was nonsignificant (OR: 1.19, 95% confidence interval [CI]: 0.98 to 1.46). The TICI2b/3 scores (OR: 0.71, 95% CI: 0.58-0.88) in M2 occlusion were remarkably lower than those in M1. The mortality and symptomatic intracerebral hemorrhage rates were comparable between the 2 groups. When comparing M2 and M1 occlusions, we found that there was no significant difference between stent retriever and aspiration in the modified Rankin Score (0-2) after AIS, but aspiration exerted an eminently higher recanalization rate with regard to TICI2b/3 (OR: 0.77, 95% CI: 0.61-0.96).

CONCLUSIONS

Compared with M1 occlusion, patients with M2 occlusion treated by MT demonstrated similar clinical outcomes in this study. Moreover, there was no difference between stent retriever and aspiration in treating M2 occlusion in terms of functional independence at 90 days. However, aspiration exerted a conspicuously higher recanalization rate in M2 occlusion than in M1 occlusion.

Experimental Validation of Pullout Resistance for Stent Retrievers and Aspiration Catheters

Objective

Stretching or avulsion of a small perforating artery caused by mechanical traction contributes to intracranial hemorrhagic complications in mechanical thrombectomy, especially for medium and small-vessel occlusions. This study aimed to measure the pullout resistance during stent retriever (SR) traction and aspiration catheter (AC) traction with or without thrombi and characterize the mechanical properties of each device.

Methods

We placed the thrombectomy device in the area corresponding to the insular segment of the middle cerebral artery of a silicon carotid artery model. The thrombectomy device was automatically pulled out at a constant velocity using a horizontal motorized test stand, and pullout resistance was continuously measured 2000 times per second using a digital force gauge. Five types of SRs and two types of ACs with or without thrombus were evaluated. The data were divided into four groups for analysis: SR without clot, SR with clot, AC without clot, and AC with clot.

Results

The line graph was a jagged waveform during SR traction, and it was a gentle curve during AC traction. The maximum pullout resistance was higher in the SR with clot group than the other groups. The coefficient of variation was higher in the SR group than the AC group, with or without clot.

Conclusion

The pullout resistance during SR traction was more fluctuated than that during AC traction. In the presence of a thrombus, pullout resistance for SR was substantially increased, whereas AC resistance was less susceptible to thrombi. The differences in characteristics may reflect differences in the frequency of mechanical traction injury between the devices during clinical use.

Stent-retriever alone versus combined use of stent-retriever and contact aspiration technique for middle cerebral artery M2 occlusions: a propensity score analysis

BACKGROUND

The optimal endovascular treatment (EVT) technique for middle cerebral artery (MCA) M2 segment occlusions remains unknown. We aim to analyze whether reperfusion rate, procedure times, procedure-related complications, and clinical outcome differed between patients with isolated M2 occlusions who underwent stent-retriever (SR) alone versus combined SR and contact aspiration (CA) as a front-line EVT.

METHODS

Patients who underwent EVT for isolated MCA-M2 occlusion were recruited from the prospectively ongoing ROSSETTI registry. Patients were divided regarding the EVT approach into SR alone versus SR+CA and propensity score matching was used to achieve baseline balance. Demographic, procedural, safety, and clinical outcomes were compared between groups. Multivariable logistic regression analysis was performed to identify independent predictors of first-pass effect (FPE) and 90-day modified Rankin scale (mRS) 0-2.

RESULTS

214 patients underwent EVT for M2 occlusion, 125 treated with SR alone and 89 with SR+CA. Propensity score matchnig analysis selected 134 matched patients. The rates of FPE (42% vs 40%, p=1.000) and 90-day mRS 0-2 (60% vs 51%, p=0.281) were comparable between groups. Patients treated with SR alone had lower need of rescue therapy (p=0.006), faster times to reperfusion (p<0.001), and lower procedure-related complications (p=0.031). Higher initial Alberta Stroke Program Early CT Score was an independent predictor of FPE. Age, baseline National Institutes of Health Stroke Scale score, and procedure duration were significant predictors of good clinical outcome at 3 months.

CONCLUSIONS

As front-line modality in M2 occlusions, the SR alone approach results in similar rates of reperfusion and good clinical outcomes to combined SR+CA and might be advantageous due to faster reperfusion times and fewer adverse events.

Initial Experience Performing Mechanical Thrombectomy With the CatchView Mini Device for Distal M2 Segment Middle Cerebral Artery Occlusions

Background: Mechanical thrombectomy (MT) has become the standard of care for acute ischemic stroke due to large vessel occlusion; however, its safety and efficacy in patients with distal strokes remains unclear. In this study, we investigated the safety and efficacy of MT for distal middle cerebral artery (MCA) occlusions using the CatchView Mini (CVM; Balt, Montmorency, France).

Methods: This was a prospective single-center analysis of patients with a single MCA-M2 occlusion treated with the CVM device. Consecutive patients were prospectively enrolled from October 2018 to March 2020. Efficacy outcomes included successful recanalization [modified Thrombolysis in Cerebral Infarction (mTICI) 2b/3], procedure times, and number of device passes. Clinical outcomes included National Institutes of Health Stroke Scale Score (NIHSS) at discharge, 90-day functional independence (modified Rankin Scale 0–2) and safety outcomes included hemorrhagic complications, and 90-day mortality.

Results: A total of 45 patients (mean age: 74.0 ± 12.6; 53.3% [24/45] female) were included in the study. Upon admission, 33.3% (15/45) of patients were mRS 3–5; and mean NIHSS was 13.2 ± 4.2 Mean time from symptom onset to final angiography was 250.0 ± 83.4 min with a mean intervention duration of 34.0 ± 12.6 min. The mean number of device passes was 1.8 ± 1.5 final mTICI 2b/3 was achieved in 91.1% (41/45) of patients. Eight hemorrhagic complications (17.8%, 8/34) occurred, none of which were symptomatic. At 90-days, 57.8% (26/45) patients were functionally independent and the rate of mortality was 15.6% (7/45).

Conclusions: The present analysis demonstrates a low risk profile and high recanalization success for patients with distal M2 occlusions treated with the CVM device.

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.

Systematic review and meta-analysis of current rates of first pass effect by thrombectomy technique and associations with clinical outcomes

BACKGROUND

First pass effect (FPE) in mechanical thrombectomy is thought to be associated with good clinical outcomes.

OBJECTIVE

To determine FPE rates as a function of thrombectomy technique and to compare clinical outcomes between patients with and without FPE.

METHODS

In July 2020, a literature search on FPE (defined as modified Thrombolysis in Cerebral Infarction (TICI) 2c-3 after a single pass) and modified FPE (mFPE, defined as TICI 2b-3 after a single pass) and mechanical thrombectomy for stroke was performed. Using a random-effects meta-analysis, we evaluated the following outcomes for both FPE and mFPE: overall rates, rates by thrombectomy technique, rates of good neurologic outcome (modified Rankin Scale score ≤2 at day 90), mortality, and symptomatic intracerebral hemorrhage (sICH) rate.

RESULTS

Sixty-seven studies comprising 16 870 patients were included. Overall rates of FPE and mFPE were 28% and 45%, respectively. Thrombectomy techniques shared similar FPE (p=0.17) and mFPE (p=0.20) rates. Higher odds of good neurologic outcome were found when we compared FPE with non-FPE (56% vs 41%, OR=1.78) and mFPE with non-mFPE (57% vs 44%, OR=1.73). FPE had a lower mortality rate (17% vs 25%, OR=0.62) than non-FPE. FPE and mFPE were not associated with lower sICH rate compared with non-FPE and non-mFPE (4% vs 18%, OR=0.41 for FPE; 5% vs 7%, OR=0.98 for mFPE).

CONCLUSIONS

Our findings suggest that approximately one-third of patients achieve FPE and around half of patients achieve mFPE, with equivalent results throughout thrombectomy techniques. FPE and mFPE are associated with better clinical outcomes.