Larger ACE 68 aspiration catheter increases first-pass efficacy of ADAPT technique

Contact aspiration for basilar artery occlusion safely reduces the puncture-to-recanalization time

OBJECTIVE

Effective thrombectomies in the posterior circulation remain controversial. Previous reports have demonstrated the superiority of contact aspiration in anterior circulation. Aspiration catheters and stent retrievers are often used alone on a global scale, while combined techniques are commonly used in Japan. This study evaluated the effect of first-line contact aspiration with other strategies for the treatment of basilar artery occlusion.

METHODS

The primary outcome was the frequency of the first-pass effect, and the secondary outcome was the time from puncture to the first-pass effect. A multicenter observational registry including 16 Japanese stroke centers was used. Between December 2013 and February 2021, enrolled patients underwent endovascular thrombectomy for basilar artery occlusion. The efficacy of contact aspiration compared to other methods (including stent retrievers and combined techniques) was evaluated.

RESULTS

Eighty-four patients were included, all of whom had achieved effective recanalization. Twenty-six patients were treated with contact aspiration, 13 with combined technique, and 45 with stent retrievers. The two groups: contact aspiration and non-contact aspiration, had different backgrounds. Both had similar frequencies of effective recanalization and first-pass effects. The contact aspiration group experienced better functional outcomes without statistical significance, while this strategy was significantly associated with a shorter puncture-to-recanalization time (38 vs. 55 minutes, P=0.036). In particular, in the 55 patients with the first-pass effect, multivariate Cox proportional hazard analysis showed that contact aspiration was significantly associated with a shorter time from puncture to first-pass effect, independent of age and etiology of large-artery atherosclerosis (hazard ratio 2.02, 95% confidence intervals 1.10-3.69, P=0.023).

CONCLUSION

This study suggested that contact aspiration for basilar artery occlusion may shorten the puncture-to-first-pass effect, compared to stent retrievers and combined techniques.

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.

Assessment of the safety and efficacy of the Zoom 45 and 55 reperfusion catheters for medium and distal mechanical thrombectomies: A multi-institutional study

INTRODUCTION

The Zoom aspiration catheters harbor novel dimensions and construction to enhance trackability and deliverability. In addition, a beveled tip may improve thrombus interaction and aspiration force for a set inner diameter. This study evaluates their utility in medium and distal vessel occlusions.

OBJECTIVE

To evaluate the safety and efficacy of Zoom 45 and 55 aspiration catheters in medium and distal vessel thrombectomy.

METHODS

Patients treated for distal vessel occlusions via mechanical thrombectomy utilizing either the Zoom 45/55 catheter or a historical control catheter between 2021-2022 at two institutions were included in this study. Medium and distal occlusions were defined as any anterior or posterior cerebral artery branch as well as the M2-4 segment of the middle cerebral artery (MCA). Preprocedural, procedural, and postprocedural variables were obtained.

RESULTS

Thirty-eight patients underwent thrombectomy with Zoom 45 or 55 catheters; four had multiple occluded vessels. Occlusion location included the M2 in 32 cases, M3-4 in 7 cases, A2 in 2 cases and P2 in 1 case. The mean number of passes per occlusion was 1.6 and overall successful reperfusion (TICI 2b or greater) was achieved in 84 % of cases. There were no symptomatic procedure-related complications such as perforation or post-procedural symptomatic ICH. Modified Rankin scores rates of 0-2, 3-5, and 6 at three months post-procedure were 35.7 %, 21.4 %, and 42.9 %, respectively.

CONCLUSIONS

The Zoom beveled tip aspiration catheters are safe and effective for more challenging medium and distal vessel occlusions.

Optimizing catheter centering enhances mechanical thrombectomy success: Performance difference in cases using novel macrowires versus traditional microwires

BACKGROUND

The aim of this study is to determine how guidewire selection impacts procedure time and success and analyze if the trend toward the adoption of larger diameter guidewires provides a quantifiable advantage over traditional 0.014″ guidewires.

METHODS

A review of 494 consecutively performed acute ischemic stroke cases performed between 2018 and 2022 were reviewed and grouped into cases using a single 0.014″ outer diameter (OD) guidewire (195 cases) and cases using a single 0.018″ or 0.024″ OD guidewire (128 cases). These groups were compared for differences in average time to recanalization, average number of passes to achieve recanalization, and first pass success. Cases were compared overall, and further analyzed by region of occlusion to look at specific guidewire related differences for cases with M1, M2, and ICA occlusions.

RESULTS

Procedures using a larger OD guidewire have an average 5 min and 30 s reduction in time from puncture to recanalization (p = 0.0201). ICA occlusion cases using a larger macrowire show a 20 min reduction in recanalization time (p = 0.0005), a reduction in average number of passes from 2.6 to 1.7 (p = 0.0058), and an increase in first pass success from 18.8% to 58.3% when compared to traditional guidewires.

CONCLUSION

Large 0.018″ or 0.024″ OD guidewires better fill the lumen of the catheter and help to center the thrombectomy system in the vessel and navigate to the clot face. This leads to a reduction in procedure time and number of passes, and an increase in first pass success, especially when treating occlusions in the ICA.

Combined technique as first approach in mechanical thrombectomy: Efficacy and safety of REACT catheter combined with stent retriever

INTRODUCTION

Mechanical thrombectomy (MT) with combined treatment including both a stent retriever and distal aspiration catheter may improve recanalization rates in patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO). Here, we evaluated the effectiveness and safety of the REACT aspiration catheter used with a stent retriever.

METHODS

This prospective study included consecutive adult patients who underwent MT with a combined technique using REACT 68 and/or 71 between June 2020 and July 2021. The primary endpoints were final and first pass mTICI 2b-3 and mTICI 2c-3 recanalization. Analysis was performed after first pass and after each attempt. Secondary safety outcomes included procedural complications, symptomatic intracranial hemorrhage (sICH) at 24 h, in-hospital mortality, and 90-day functional independence (modified Rankin Scale [mRS] 0-2).

RESULTS

A total of 102 patients were included (median age 78; IQR: 73-87; 50.0% female). At baseline, median NIHSS score was 19 (IQR: 11-21), and ASPECTS was 9 (IQR: 8-10). Final mTICI 2b-3 recanalization was achieved in 91 (89.2%) patients and mTICI 2c-3 was achieved in 66 (64.7%). At first pass, mTICI 2b-3 was achieved in 55 (53.9%) patients, and mTICI 2c-3 in 37 (36.3%). The rate of procedural complications was 3.9% (4/102), sICH was 6.8% (7/102), in-hospital mortality was 12.7% (13/102), and 90-day functional independence was 35.6% (36/102).

CONCLUSION

A combined MT technique using a stent retriever and REACT catheter resulted in a high rate of successful recanalization and first pass recanalization in a sample of consecutive patients with AIS due to LVO in clinical use.

Impact of aspiration catheter size on clinical outcomes in aspiration thrombectomy

BACKGROUND

Direct aspiration thrombectomy is a well-established method for mechanical thrombectomy in acute ischemic stroke. Yet, the influence of aspiration catheter internal diameter (ID) on aspiration thrombectomy efficacy is incompletely understood.

METHODS

A systematic literature review and meta-regression analysis was completed to evaluate the impact of primary aspiration thrombectomy outcomes based on the ID of the aspiration catheter. Primary outcome measures were: final recanalization of modified Thrombolysis In Cerebral Ischemia (mTICI) 2b-3 with aspiration only and with rescue modalities, first pass effect (FPE), need for rescue modalities, intracranial hemorrhagic complication rates, and functional outcomes of 90-day modified Rankin Scale (mRS) of 0-2.

RESULTS

30 studies were identified with 3228 patients. Meta-regression analysis revealed a significant association between increasing aspiration catheter ID and FPE (p=0.032), between ID and final recanalization with aspiration only (p=0.05), and between ID size and recanalization including cases with rescue modalities (p=0.002). Further, subgroup analysis indicated that catheters with an ID ≥0.064 inch had a lower rate of need for rescue than smaller catheters (p=0.013). Additionally, catheters with an ID ≥0.068 inch had a higher rate of intracranial bleeding complications (p=0.025). Lastly, no significant association was found in functional outcomes overall.

CONCLUSIONS

Larger aspiration catheters are associated with a higher rate of FPE, final recanalization with only an aspiration catheter, and in cases with rescue modalities, though with a higher rate of hemorrhagic complications. These findings confirm that aspiration catheter size functions as a variable in aspiration thrombectomy, which should be considered in future study and trial design.

First-Pass Effect in M1-Occlusion Stroke Patients Treated with Combined Stent-Retriever/Large-Bore Distal Aspiration Catheter Thrombectomy

INTRODUCTION

Combined stent-retriever/large-bore distal aspiration catheter (LB-DAC) thrombectomy was recently introduced to treat large-vessel occlusion; however, it is unclear whether larger inner diameters improve outcomes. We compared angiographic and clinical outcomes in patients with occlusions of the M1 segment of the middle cerebral artery treated with mechanical thrombectomy using extra-LB-DAC versus LB-DAC in combination with stent-retrievers.

METHODS

We analyzed consecutive patients with M1 occlusion included in the ROSSETTI registry treated with non-balloon guide catheter combined LB-DAC/stent-retriever thrombectomy between June 2019 and April 2022. We compared demographics, baseline clinical variables, procedural variables, angiographic outcomes, and clinical outcomes [National Institute of Health Stroke Scale score at 24 h (24h-NIHSS) and modified Rankin scale score at 3 months] between patients treated with extra-LB-DAC (Sofia Plus, MIVI Q6, Catalyst7; inner diameter, 0.068″-0.070″) versus LB-DAC (Sofia 5F, MIVI Q5, Catalyst 6; inner diameter, 0.055″-0.064″). Primary outcome was the first-pass effect (FPE) rate, defined as near-complete/complete reperfusion (mTICI 2c-3) after a single pass of the device.

RESULTS

We included 324 patients (extra-LB-DAC, 185, 57.1% patients). Demographics, clinical data, and clinical outcomes were similar between the two groups; however, there was a trend towards improvement in National Institute of Health Stroke Scale score at 24 h (24h-NIHSS) in the cohort treated with extra-LB-DAC 9 points (IQR 4;16 points) vs. 12 points (IQR 4;18 points, P = 0.083). Patients treated with extra-LB-DAC had higher FPE rate (47% vs. 30.9%; P = 0.003) and higher modified FPE (mTICI ≥ 2b after a single pass) rate (65.9% vs 46.8%; P = 0.001). The use of extra-LB-DAC was an independent factor in predicting FPE (odds ratio 1.982, 95% confidence interval 1.250-3.143, P = 0.004).

CONCLUSION

Our results suggest that in combined LB-DAC/stent-retriever thrombectomy, a larger aspiration catheter inner diameter is associated with higher rates of FPE and mFPE.

Efficacy and Safety of the Soft Torqueable Catheter Optimized For Intracranial Access in the Endovascular Treatment of Acute Ischemic Stroke: A Meta-Analysis

OBJECTIVE

Acute ischemic stroke (AIS) is a severe, life-threatening type of stroke with poor prognosis and high recurrence rate, mainly attributed to large vessel occlusion (LVO). Improved understanding of the safety and effectiveness of the Soft Torqueable Catheter Optimized For Intracranial Access (SOFIA) for LVO-AIS might guide practitioners. Therefore, we conducted this study focusing on neurological outcomes, procedure-related complications, and recanalization rates.

METHODS

We collected data in January 2022 from PubMed, Cochrane, Web of Science, and Embase. The study considered that assessed the effects of the SOFIA catheter in treatment of LVO-AIS. We extracted data narratively and expressed the results with the proportions and 95% confidence intervals (CI).

RESULTS

We included 17 studies reporting on 2106 patients treated with the SOFIA catheter. The successful recanalization rate was 77% (95% CI, 71%-83%) with the SOFIA catheter alone and the application of a rescue stent-retriever was observed in 28% (95% CI, 23%-33%) of cases, resulting in an overall successful recanalization rate of 90% (95% CI, 87%-92%). A pooled estimate of 45% (95% CI, 39%-51%) was observed for functional independence at 90 days, 15% (95% CI, 11%-20%) for mortality at 90 days, and 5% (95% CI, 3%-8%) for symptomatic intracranial hemorrhage.

CONCLUSIONS

This meta-analysis revealed that aspiration thrombectomy with the SOFIA catheter is a safer and effective treatment modality for LVO-AIS.

Experimental evaluation of the performance of large bore aspiration catheters

BACKGROUND AND PURPOSE

Mechanical thrombectomy using an aspiration catheter (AC) is widely performed in patients with acute ischemic stroke due to large vessel occlusion. AC diameter directly impacts aspiration performance, which has led device companies to develop large bore ACs. The purpose of this study was to evaluate the in vitro performance of several commercially available large bore ACs.

MATERIALS AND METHODS

We conceived an experimental set up to assess tracking force, aspiration flow rate, and distal end tensile force pre- and post-thrombectomy of ACs including Sofia 6 (Microvention Inc., California, USA), React 71 (Medtronic Neurovascular, Irvine, California, USA), Jet 7 (Penumbra Inc, Alameda, California, USA), Catalyst 7 (Stryker Neurovascular, Kalamazoo, Michigan, USA) and Embovac 071 (Johnson & Johnson Medical Ltd, UK).

RESULTS

React 71 and Sofia 6 had significantly lower trackability force compared to the other ACs tested. Distal AC segment tensile force was highest for React 71 and lowest for Jet 7. Jet 7 had the highest internal diameter and the highest aspiration flow rate.

CONCLUSION

The data from this comparative analysis may assist clinicians in selecting the appropriate AC and highlights the need for key performance criteria during the development of next-generation large-bore ACs for optimal AC performance.

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.

Impact of Increasing Aspiration Catheter Size and Refinement of Technique: Experience of Over 1000 Strokes Treated With ADAPT

BACKGROUND

We present longitudinal data regarding the outcomes and evolution of mechanical thrombectomy (MT) using a direct aspiration first pass technique.

OBJECTIVE

To evaluate the impact of increasing aspiration catheter size.

METHODS

This is a planned analysis of a prospective cohort study that enrolled all patients who underwent a direct aspiration first pass technique MT in a comprehensive stroke center from January 2013 to December 2020. We did exploratory analysis of the characteristics and outcomes of patients who had intracranial internal carotid artery or M1 segment of middle cerebral artery occlusion based on the aspiration catheter bore size (small [041, 054, 058, and 060 inch] vs medium [0.064 and 0.068 inch] and medium vs large [0.071, 0.072, and 0.074 inch]).

RESULTS

During the 8-year study period, a total of 1004 patients were included. Median age was 69 years, 49% were female patients, and 60.6% were White. Symptomatic hemorrhagic transformation was observed in 47 patients (4.7%), and 366 patients (36.5%) achieved the modified Rankin scale of 0 to 2 at 90 days after the stroke. For patients with intracranial internal carotid artery or M1 occlusion, medium-bore aspiration catheters were more likely to achieve successful recanalization after first aspiration attempt (63.9% vs 51.4%, P = .015) and had a faster groin-to-reperfusion time (16 vs 20 minutes, P = .001) when compared with small-bore catheters. However, these differences were not significant when comparing medium-bore with large-bore catheters.

CONCLUSION

Medium-bore catheters had better performance measures compared with small-bore catheters. However, large-bore catheters did not show significantly better performance results that suggest a plateau effect.

Flow control in the middle cerebral artery during thrombectomy: the effect of anatomy, catheter size and tip location

BACKGROUND

Catheter size, location and circle of Willis anatomy impact the flow conditions during interventional stroke therapy. The aim of the study was to systematically investigate the influence of these factors on flow control in the middle cerebral artery by means of a computational model based on 100 patients with stroke who received endovascular treatment.

METHODS

The dimensions of the cervical and intracranial cerebral arteries of 100 patients who received endovascular mechanical thrombectomy for acute ischemic stroke were measured and a three-dimensional model of the circle of Willis was created based on these data. Flow control in the middle cerebral artery with variations in catheter size, catheter location and configurations of collateral vessels was determined using a computational model. A total of 48 scenarios were analyzed.

RESULTS

Flow reversal with a distal aspiration catheter alone was not possible in the internal carotid artery and only sometimes possible in the middle cerebral artery (14 of 48 cases). The Catalyst 7 catheter was more often successful in achieving flow reversal than Catalyst 5 or 6 catheters (p<0.001). In a full circle of Willis anatomy, flow reversal was almost never possible. The absence of one or more communicating arteries significantly influenced flow direction compared with the full anatomy with all communicating arteries present (p=0.028).

CONCLUSION

Choosing the biggest possible aspiration catheter and locating it in the middle cerebral artery significantly increases the chances of successful flow control. Flow through the collaterals may impair the flow, and circle of Willis anatomy should be considered during aspiration thrombectomy.

Predictors of First-Pass Effect in Endovascular Thrombectomy With Stent-Retriever Devices for Acute Large Vessel Occlusion Stroke

Background and Purpose

Successful recanalization after the first pass of the device in endovascular thrombectomy (EVT) can significantly improve patients' prognosis. We aimed to investigate the possible factors that influence achieving the first-pass effect (FPE).

Methods

We retrospectively analyzed the patients who underwent EVT caused by anterior circulation large vessel occlusion stroke (ALVOS) in our center. The FPE was defined as a successful recanalization [modified Thrombolysis in Cerebral Infarction (mTICI) 2b/3 defined as modified FPE (mFPE); mTICI 3 as true FPE (tFPE)] after one pass of the device without rescue therapy. Univariate and multivariate regression analyses were used to explore the predictors of FPE and the relationship between FPE and prognosis.

Results

There were 278 patients (age, 69.3 ± 10.9 years, male, 51.1%) included, 30.2% of them achieved mFPE, while 21.2% achieved tFPE. We found the higher clot burden score (CBS), the truncal-type occlusion, and the favorable anatomy of both extracranial and intracranial segments of the internal carotid artery (ICA) were associated with achieving mFPE. The higher CBS and truncal-type occlusion were statistically significant predictors of tFPE. Moreover, FPE was significantly associated with improved clinical outcomes, regardless of mFPE and tFPE.

Conclusions

The CBS, tortuosity of ICA, and angiographic occlusion type were independent predictors of achieving FPE. The rate of improved clinical and safety outcomes was higher in patients with FPE, which has important clinical significance.

JET 7 catheter for direct aspiration in carotid T occlusions: preliminary experience and literature review

OBJECTIVE

We report our preliminary experience with the Penumbra JET 7 reperfusion catheter (JET 7), a new large-bore (0.072″) aspiration catheter, in patients with acute ischemic stroke (AIS) due to carotid T occlusion.

METHODS

Data of all eligible patients who received A Direct Aspiration First Pass Technique (ADAPT) for AIS due to carotid T occlusion at our center from March 2018 through June 2020 were retrospectively reviewed. The safety and performance of JET 7 cases and smaller large-bore catheters (LBCs) were compared.

RESULTS

JET 7 was used in 19 patients, and smaller LBCs were used in 41 patients. Median puncture to revascularization time was significantly different between the JET 7 and the smaller LBCs (16 vs. 27 min; P = 0.011). The rate of patients who received rescue therapy with a stent retriever was also significantly different between the JET 7 cases and the smaller LBCs cases (5.3% vs. 22.0%; P = 0.046). Successful revascularization (TICI ≥ 2b) was achieved in 94.7% of JET 7 cases and 75.6% of smaller LBCs cases (P = 0.148). Good functional outcome (mRS 0-2) at 90 days occurred in 63.2% of JET 7 cases and 46.3% of smaller LBCs cases (P = 0.274).

CONCLUSIONS

In this early experience, ADAPT with JET 7 could be considered as one of the possible first-line therapies in carotid T occlusion, showing good rate of vascularization and lower rate of rescue therapy in comparison with smaller LBCs.

Intravenous Alteplase is Associated with First Pass Effect in Stent-retriever but not ADAPT Thrombectomy : Post Hoc Analysis of the SKIP Study

PURPOSE

To investigate the effect of alteplase, either combined with stent-retriever thrombectomy or a direct aspiration first pass technique (ADAPT), in patients with large-vessel occlusion stroke.

METHODS

This was a retrospective post hoc analysis of data from The Direct Mechanical Thrombectomy in Acute LVO Stroke (SKIP) study. Patients were divided into two groups according to the first-line thrombectomy technique: stent-retriever and ADAPT. Each group was further divided into two subgroups, namely MT and MT + alteplase. The procedural outcomes, such as first pass effect (FPE) ratio and number of passes, were evaluated. The clinical outcomes included mRS score at 3 months.

RESULTS

A total of 180 patients were included (116 in the stent-retriever group and 64 in the ADAPT group). No interaction was detected between the first-line technique and alteplase administration. In the stent-retriever group, after adjusting for factors associated with FPE, the adjusted odds ratio (95% confidence interval) of FPE of the MT + alteplase subgroup versus the MT subgroup was 3.57 (1.5-8.48) and in the ADAPT group it was 1.35 (0.37-4.91). With alteplase, the number of passes decreased with adjusted odds ratios of 0.59 (0.37-0.93) in the stent-retriever group but not in the ADAPT group. In both first-line technique groups, clinical outcomes did not differ between subgroups.

CONCLUSION

In the SKIP study, alteplase administration was associated with increased FPE when combined with stent-retriever thrombectomy, but not with ADAPT. We found no differences in the clinical outcomes.

When Two Is Better than One : The Buddy-wire Technique in Flow-diversion Procedures

Background

Delivery of most flow diverters (FD) requires larger, and thus stiffer microcatheters (0.021–0.027in.) which can pose challenges to intracranial navigation. The concomitant use of two microwires within one microcatheter, also known as the buddy-wire technique, may be helpful for navigation and support in challenging situations.

Methods

We analyzed all flow diverter procedures in our prospectively collected database. We recorded all patient-related, anatomical and procedural information. We performed univariate statistics and technical descriptions.

Results

In total, 208 consecutive patients treated with a FD at our institution between July 2014 and August 2020 were retrospectively analyzed. In 17 patients the buddy-wire technique was used (mean age 63 years, range 31–87 years: 16 female). Aneurysms were located at the petrous, cavernous, supraophthalmic internal carotid artery, and a proximal M2 branch in 2, 7, 7 and 1 patient(s), respectively. In all cases a 0.027in. microcatheter was used for device deployment. In 14 patients with a wide-necked aneurysm the buddy-wire provided additional support to advance the microcatheter and mitigated the ledge between the aneurysm neck and the parent artery or a side branch. In two giant cavernous aneurysms treated with telescoping FDs, the buddy-wire was used to re-enter the proximal end of the foreshortened FD.

Conclusion

The buddy-wire is a useful technique in FD procedures to prevent herniation of the microcatheter into the aneurysm sack, in wide-necked aneurysms to mitigate the ledge effect between the aneurysm neck and the parent artery where the microcatheter tip may get stuck, or to enable re-entry into a foreshortened FD.

Stent-retriever alone vs. aspiration and stent-retriever combination in large vessel occlusion stroke: A matched analysis

BACKGROUND

Three randomized clinical trials have reported similar safety and efficacy for contact aspiration and stent-retriever thrombectomy.

AIM

We aimed to determine whether the combined technique (stent-retriever + contact aspiration) was superior to stent-retriever alone as first-line thrombectomy strategy in a patient cohort where balloon guide catheter was universally used.

METHODS

A prospectively maintained mechanical thrombectomy database from January 2018 to December 2019 was reviewed. Patients were included if they had anterior circulation proximal occlusion ischemic stroke (intracranial ICA or MCA-M1/M2 segments) and underwent stent-retriever alone thrombectomy or stent-retriever + contact aspiration as first-line therapy. The primary outcome was the first-pass effect (mTICI2c-3). Secondary outcomes included modified first-pass effect (mTICI2b-3), successful reperfusion (mTICI2b-3) prior to and after any rescue strategy, and 90-day functional independence (mRS ≤ 2). Safety outcomes included rate of parenchymal hematoma type-2 and 90-day mortality. Sensitivity analyses were performed after dividing the overall cohort according to first-line modality into two matched groups.

RESULTS

A total of 420 patients were included in the analysis (mean age 64.4 years; median baseline NIHSS 16 (11-21)). As compared to first-line stent-retriever alone, first-line stent-retriever + contact aspiration resulted in similar rates of first-pass effect (53% vs. 51%, adjusted odds ratio (aOR) 1.122, 95%CI (0.745-1.691), p = 0.58), modified first-pass effect (63% vs. 60.4%, aOR1.250, 95%CI (0.782-2.00), p = 0.35), final successful reperfusion (97.6% vs. 98%, p = 0.75), and higher chances of successful reperfusion prior to any rescue strategy (81.8% vs. 72.5%, aOR 2.033, 95%CI (1.209-3.419), p = 0.007). Functional outcome and safety measures were comparable between both groups. Likewise, the matched analysis (148 patient-pairs) demonstrated comparable results for all clinical and angiographic outcomes except for significantly higher rates of successful reperfusion prior to any rescue strategies with the first-line stent-retriever + contact aspiration treatment (81.8% vs. 73.6%, aOR 1.881, 95%CI (1.039-3.405), p = 0.037).

CONCLUSIONS

Our findings reinforce the findings of ASTER-2 trial in that the first-line thrombectomy with a combined technique did not result in increased rates of first-pass reperfusion or better clinical outcomes. However, the addition of contact aspiration after initial stent-retriever failure might be beneficial in achieving earlier reperfusion.

Bigger is Still Better: A Step Forward in Reperfusion With React 71

BACKGROUND

While multiple new larger-bore aspiration catheters have been introduced for stroke thrombectomy, sizeable cohort outcome studies are lacking along with meaningful comparative studies to evaluate whether they represent a clinically relevant improvement compared to predecessors.

OBJECTIVE

To evaluate comparative angiographic and clinical outcomes between an 071 and 068 aspiration catheter.

METHODS

The authors reviewed an institutional thrombectomy database extracting the first 150 consecutive cases utilizing React 71 (Medtronic, Dublin, Ireland) with a comparison of background/demographic, procedural, angiographic, and clinical outcome variables to a cohort of patients treated with our previously most frequently utilized 0.068-inch aspiration catheter.

RESULTS

In our React 71 cohort, successful reperfusion (thrombolysis in cerebral infarction [TICI] 2b-3) was achieved in 95% of cases. In comparison to a prior cohort of 96 patients treated with a 0.068-inch catheter, there was no statistically significant difference in rates of successful reperfusion (TICI 2b-3), initial disposition, and 90-d outcome. However, the frequency of single pass cases was significantly higher in the React 71 cohort (47% vs 35%, P = .019 on multivariate analysis) along with the rate of TICI 2c-3 reperfusion after the first pass (26% vs 14%, P = .019 on multivariate analysis), and final TICI 2c-3 reperfusion (39% vs 28%, P = .04 on multivariate analysis).

CONCLUSION

While rates of TICI 2b-3 reperfusion and clinical outcome results were similar, our study suggests that a newer, larger bore aspiration catheter may be associated with a greater frequency of single pass cases and higher quality reperfusion, judged as TICI 2c-3 frequency after the first and final pass.

Clinical impact of the first pass effect on clinical outcomes in patients with near or complete recanalization during mechanical thrombectomy for large vessel ischemic stroke

BACKGROUND AND PURPOSE

The first pass effect has been reported as a mechanical thrombectomy (MT) success metric in patients with large vessel occlusive stroke. We aimed to compare the clinical and neuroimagign outcomes of patients who had favorable recanalization (mTICI 2c or mTICI 3) achieved in one pass versus those requiring multiple passes.

METHODS

In this "real-world" multicenter study, patients with mTICI 2c or 3 recanalization were identified from three prospectively collected stroke databases from January 2016 to December 2019. Clinical outcomes were a favorable functional outcome at 90 days (modified Rankin Scale score 0-2), and the rate of symptomatic intracranial hemorrhage (ICH) any ICH, and 90-day mortality.

RESULTS

Favorable recanalization was achieved in 390/664 (59%) of consecutive patients who underwent MT (age 71.2 ± 13.2 years, 188 [48.2%] women). This was achieved after a single thrombectomy pass (n = 290) or multiple thrombectomy passes (n = 100). The rate of favorable clinical outcome was higher (41% vs. 28 %, p = .02) in the first pass group with a continued trend on multivariate analysis that did not reaching statistical significance (OR 1.68 95% confidence interval [CI] 1.0-2.95, p = .07). Similarly, the odds of any ICH were significantly lower (OR 0.56 CI 0.32-0.97, p = .03). A similar trend of favorable clinical outcomes was noticed on subgroup analysis of patients with M1 occlusion (OR 1.81 CI 1.01-3.61, p = .08).

CONCLUSION

The first-pass reperfusion was associated with a trend toward favorable clinical outcome and lower rates of ICH. These data suggest that the first-pass effect should be the mechanical thrombectomy procedure goal.

Impact of aspiration catheter size on first-pass effect in the combined use of contact aspiration and stent retriever technique

Background and purpose

The first-pass effect (FPE), defined as a first-pass Expanded Treatment in Cerebral Ischaemia (eTICI) 2c/3 reperfusion, has emerged as a key metric of efficacy in mechanical thrombectomy (MT) for acute ischaemic stroke. The proximal balloon occlusion together with direct thrombus aspiration during stent retriever thrombectomy (PROTECT)-PLUS technique consists in the use of a balloon guide catheter and a combined MT approach involving contact aspiration and a stent retriever. The aim of this study is to assess the effectiveness and safety of the PROTECT-PLUS technique using distal aspiration catheters (DACs) with different inner diameters by comparing the large-bore DAC Catalyst 7 versus the use of medium-bore DACs.

Methods

Retrospective analysis of a prospectively maintained database of patients treated with PROTECT-PLUS using Catalyst 7, Catalyst 6 or Catalyst 5 with an occlusion of either the terminal carotid artery or the M1 or M2 segments of the middle cerebral artery from 2018 to 2020 in two comprehensive stroke centres. Baseline characteristics and procedural, safety and clinical outcomes were compared between groups. Multivariable logistic regression analysis was performed in order to find independent predictors of FPE.

Results

We identified 238 consecutive patients treated with PROTECT-PLUS as front-line approach using Catalyst 7 (n=86), Catalyst 6 (n=78) and Catalyst 5 (n=76). The rate of FPE was higher with Catalyst 7 (54%) than Catalyst 6 (33%, p=0.009) and Catalyst 5 (32%, p=0.005), in addition to higher final eTICI 2c/3 reperfusion rates, shorter procedural times, lower need of rescue therapy and fewer procedure-related complications. After multivariable analysis the sole independent factor associated to FPE was the use of Catalyst 7 (OR 2.34; 95% CI 1.19 to 4.58; p=0.014).

Conclusion

Further development of combined MT by incorporating larger-bore aspiration catheters is associated with higher reperfusion rates, shorter procedure times, and lower need of rescue therapy while reducing the complication rates.

Maximizing the catheter-to-vessel size optimizes distal flow control resulting in improved revascularization in vitro for aspiration thrombectomy

Background

Balloon guide catheters (BGCs) achieve proximal flow control during thrombectomy but antegrade intracranial flow often persists via the Circle of Willis. Closely sizing an aspiration catheter to the target vessel might achieve greater flow control and improve technical performance. Our objective was to measure the impact of aspiration catheter size on distal flow control and flow reversal with and without the use of BGCs. Clot retrieval testing was performed to establish the impact of these parameters on revascularization.

Methods

An in vitro thrombectomy model replicated in vivo conditions. Flow was measured continuously using ultrasonic flow sensors placed 20 cm distal to the catheter tip in the middlel cerebral artery (MCA). Four aspiration catheters of increasing size were evaluated: ACE 60 and 64 (Penumbra), SOFIA Plus (MicroVention), and Millipede 088 (Perfuze). Two clot analog types (red blood cell-rich and fibrin/platelet-rich) were used for clot retrieval testing.

Results

The larger area of the ‘superbore’ Millipede 088 catheter resulted in a larger reduction in antegrade flow than standard aspiration catheters, even when the latter were combined with a BGC. During aspiration, 6Fr catheters were unable to cause flow reversal in the distal MCA while the Millipede 088 achieved significant distal flow reversal (−146 mL/min) (P<0.0001*) (*denotes significance). The solo use of Millipede 088 resulted in better recanalization outcomes and significantly reduced distal emboli for internal carotid artery (P=0.015*) and MCA (P=0.014*) occlusions compared with all other devices and combinations.

Conclusions

Maximizing the catheter-to-vessel size facilitates near flow-arrest on catheter insertion, potentially negating the need for a BGC. A 0.088 inch aspiration catheter enables significant flow reversal in the distal MCA during aspiration.

Clinical Result of Mechanical Thrombectomy Using Sofia Plus with Acute Ischemic Stroke Compared with the Stent Retriever

OBJECTIVE

The Sofia catheter is a new large-bore aspiration catheter that allows easy access and good reperfusion. In this study, we analyzed the efficacy and safety of the Sofia catheter in comparison with stent retrievers as a contact aspiration thrombectomy (CAT) tool for large vessel occlusion.

METHODS

We enrolled patients with acute ischemic stroke who underwent endovascular thrombectomy from April 2017 and April 2020 in our hospital. Patients were retrospectively reviewed and divided into the stent retriever group (SR), the Sofia group, and all cases group.

RESULTS

A total of 114 patients were treated during the study period, including 27 in the stent retriever group and 15 in the Sofia group. Higher rates of the first-pass effect (FPE) (37% vs. 47%, P = 0.12) and significantly higher modified FPE (44% vs. 67%, P = 0.001) were observed in patients with SR and Sofia, respectively. Functional independence (modified Rankin Scale ≤2) at 30 days after onset was observed in 30% versus 47% (P = 0.47) of SR and Sofia, respectively.

CONCLUSIONS

The Sofia Plus is a large-bore aspiration catheter with high FPE and good accessibility. Use of this catheter resulted better angiographic outcome compared with the stent retriever, but there was no difference in clinical outcomes in this study. Further studies are needed to compare in new generation aspiration catheters.

Radial first or patient first: a case series and meta-analysis of transradial versus transfemoral access for acute ischemic stroke intervention

BACKGROUND

Few studies have compared technical success and effectiveness of transradial access (TRA) versus transfemoral access (TFA) for mechanical thrombectomy (MT) for acute ischemic stroke (AIS). We compared the two approaches for technical success, effectiveness, and outcomes.

METHODS

We retrospectively compared TRA with TFA for AIS MT at our institute. We additionally performed a systematic review and meta-analysis of studies describing the use of TRA alone or in comparison with TFA for MT. Primary outcomes included rate of successful reperfusion (thrombolysis in cerebral infarction (TICI) >2b), number of passes, access-site complications, and 3- month mortality and favorable functional outcomes (modified Rankin Scale (mRS) score 0-2).

RESULTS

A total of 222 consecutive patients (TRA=93, TFA=129) were included in our case series. The rate of successful reperfusion was significantly higher for the TFA cohort (91.4% vs 79.6%, P=0.01) with lower mean number of passes (1.8±1.2 vs 2.4±1.6, P=0.014). Three-month mortality in the TFA group was lower (22.1% vs 40.9% for the TRA cohort (P=0.004), with a higher rate of favorable functional outcomes (51.3% vs 34.1%, P=0.015). A meta-analysis of 10 studies showed significant heterogeneity in rates of successful reperfusion (57.1% to 95.6%, heterogeneity=67.55%, P=0.001). None of the previous comparative studies reported 3-month mortality and functional outcomes.

CONCLUSIONS

This case series demonstrate a higher successful reperfusion rate, fewer passes, lower 3-month mortality, and improved 3-month functional outcomes with TFA. The systematic review highlights the inadequacy of existing evidence. Prospective comparative studies are needed before a 'radial-first' approach can be adopted for stroke intervention.

Iatrogenic intracranial vessel dissection during mechanical thrombectomy rescued by emergent stenting: 2 case reports

Intracranial vessel dissection is a procedural complication associated with endovascular treatment. However, there have been few reports on its potential causes and management during mechanical thrombectomy. In approximately 250 cases of mechanical thrombectomy over the past 5 years at our institution, iatrogenic intracranial dissection occurred in 2 patients (0.8%). In this report, we described these 2 cases that were rescued through emergent stenting. Mechanical thrombectomy, using both a stent retriever and an aspiration catheter, was performed for acute middle cerebral artery M2 occlusion in Patient 1 (a 69-year-old man) and for distal M1 occlusion in Patient 2 (an 83-year-old woman). In both cases, recanalization was achieved with the procedure, but irregular stenosis developed at the initially nonoccluded, but mildly arteriosclerotic, M1, after recanalization. During the thrombectomy procedure, the aspiration catheter sifted up to the arteriosclerotic M1. In both cases, the lesions were considered vessel dissection, due to a shift of the aspiration catheter tip into the arteriosclerotic vessel wall. Repeated percutaneous angiography with antithrombotic therapy failed to improve the lesions and to maintain the antegrade blood flow. Finally, lesions in each patient were successfully rescued through the use of emergent stenting. A drug-eluting stent for coronary use was deployed in Patient 1, and an Enterprise stent was applied in Patient 2. Inadvertent shift of the aspiration catheter into arteriosclerotic vessels can cause a serious intracranial vessel dissection. When performing mechanical thrombectomy, intracranial stents need to be available as rescue treatment devices to manage refractory iatrogenic intracranial vessel dissection.

A Case Report Using Goose Neck Microsnare for Severe Cervical Internal Carotid Artery Occlusion with Dolichoarteriopathy

Objective

We report the use of a Goose Neck microsnare for cervical internal carotid artery (ICA) occlusion in a patient with dolichoarteriopathy in whom it was difficult to achieve recanalization.

Case Presentation

A 65-year-old woman underwent thrombectomy for a tandem lesion of left M1 occlusion and left cervical ICA occlusion. Recanalization of left M1 occlusion was achieved. For left cervical ICA occlusion, we attempted multiple thrombectomy using an existing device, but a hard clot with mobility was caught due to dolichoarteriopathy, which made thrombectomy difficult. Using a Goose Neck microsnare, we were able to capture the thrombus and achieve recanalization.

Conclusion

Thrombectomy by capturing the thrombus using a Goose Neck microsnare may be useful for capturing hard clots with mobility when it is difficult to achieve recanalization with existing devices.

Suction force rather than aspiration flow correlates with recanalization in hard clots: an in vitro study model

BACKGROUND

ANA Advanced Neurovascular Access provides a novel funnel component designed to reduce clot fragmentation and facilitate retrieval in combination with stent-retrievers (SRs) in stroke patients by restricting flow and limiting clot shaving. In previous publications ANA presented excellent in vitro/in vivo efficacy data, especially with fibrin-rich hard clots. We aimed to determine the main physical property responsible for these results, namely suction force versus aspiration flow.

METHODS

We evaluated in a bench model the suction force and flow generated by ANA and compared them to other neurovascular catheters combined with a SR (Solitaire). Aspiration flow was evaluated with a flow rate sensor while applying vacuum pressure with a pump. Suction force was determined using a tensile strength testing machine and a purposely designed tool that completely seals the device tip simulating complete occlusion by a hard clot. Suction force was defined as the force needed to separate the device from the clot under aspiration. All experiments were repeated five times, and mean values used for comparisons.

RESULTS

Aspiration flow increased with the inner diameter of the device: ANA 1.85±0.04 mL/s, ACE68 3.74±0.05 mL/s, and 8F-Flowgate2 5.96±0.30 mL/s (P<0.001). After introducing the SR, the flow was reduced by an average of 0.57±0.12 mL/s. Due to its larger distal surface, ANA suction force (1.69±0.40 N) was significantly higher than ACE68 (0.26±0.04 N) and 8F-Flowgate2 (0.42±0.06 N) (P<0.001). After introducing the SR, suction force variation was not relevant except for ANA that increased to 2.64±0.41 N.

CONCLUSION

Despite lower in vitro aspiration flow, the ANA design showed a substantially higher suction force than other thrombectomy devices.

Tailored Vessel-Catheter Diameter Ratio in a Direct Aspiration First-Pass Technique: Is It a Matter of Caliber?

BACKGROUND AND PURPOSE

The aspiration technique has gained a prominent role in mechanical thrombectomy. The thrombectomy goal is successful revascularization (modified TICI ≥ 2b) and first-pass effect. The purpose of this study was to evaluate the impact of the vessel-catheter ratio on the modified TICI ≥ 2b and first-pass effect.

MATERIALS AND METHODS

This was a retrospective, single-center, cohort study. From January 2018 to April 2020, 111/206 (53.9%) were eligible after applying the exclusion criteria. Culprit vessel diameters were measured by 2 neuroradiologists, and the intraclass correlation coefficient was calculated. The receiver operating characteristic curve was used for assessing the vessel-catheter ratio cutoff for modified TICI ≥ 2b and the first-pass effect. Time to groin puncture and fibrinolysis were weighted using logistic regression. All possible intervals (interval size, 0.1; sliding interval, 0.01) of the vessel-catheter ratio were plotted, and the best and worst intervals were compared using the χ² test.

RESULTS

Modified TICI ≥ 2b outcome was achieved in 75/111 (67.5%), and first-pass effect was achieved in 53/75 (70.6%). The MCA diameter was 2.1 mm with an intraclass correlation coefficient of 0.92. The optimal vessel-catheter ratio cutoffs for modified TICI ≥ 2b were ≤1.51 (accuracy = 0.67; 95% CI, 0.58-0.76; P = 0.001), and for first-pass effect, they were significant (≤1.33; P = .31). The modified TICI ≥ 2b odds ratio and relative risk were 9.2 (95% CI, 2.4-36.2; P = 0.002) and 3.2 (95% CI, 1.2-8.7; P = .024). The odds ratio remained significant after logistic regression (7.4; 95% CI, 1.7-32.5; P = .008). First-pass effect odds ratio and relative risk were not significant (2.1 and 1.5; P > .05, respectively). The modified TICI ≥ 2b best and worst vessel-catheter ratio intervals were not significantly different (55.6% versus 85.7%, P = .12). The first-pass effect best vessel-catheter ratio interval was significantly higher compared with the worst one (78.6% versus 40.0%, P = .03).

CONCLUSIONS

The aspiration catheter should be selected according to culprit vessel diameter. The optimal vessel-catheter ratio cutoffs were ≤1.51 for modified TICI ≥ 2b with an odds ratio of 9.2 and a relative risk of 3.2.

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.

Preliminary experience with 088 large bore intracranial catheters during stroke thrombectomy

BACKGROUND AND PURPOSE

Thromboaspiration technology continues to evolve at an accelerated pace with increasing availability of larger and more navigable devices. Herein, we provide our initial experience with the intracranial navigation of a large-bore (.088" inner diameter) catheters during mechanical thrombectomy (MT).

METHODS

Retrospective review of consecutive large vessel occlusion stroke patients in whom a TracStar™ or Zoom 88™ (Imperative Care, Campbell, CA) large-bore catheters were utilized in MT. The primary outcome was successful reperfusion (eTICI2b-3) at the end of the procedure. Safety measures included procedural complications and rates of symptomatic intracranial hemorrhage.

RESULTS

Five patients (age,∼50-85 years; baseline NIHSS,17-23) were treated. The .088" catheters were used as the primary tool for contact aspiration in two patients (distal basilar artery and proximal MCA occlusions) with complete thrombus ingestion (eTICI3) during the first pass. In two patients, the .088" catheter was used for flow control where it was placed in the distal M1-segment of a patient with M2 occlusion treated with a combination of stent-retriever and .070" aspiration catheter and in the proximal M1 in a patient with distal M1 occlusion treated with .071" aspiration catheter resulting in eTICI3 reperfusion in both cases. In the fifth patient, the .088" catheter was navigated into the cavernous ICA to support .071" aspiration catheter treatment of an M2 occlusion resulting in eTCI2b67 reperfusion. Procedural duration ranged between 14 and 33 minutes. There were no adverse events.

CONCLUSION

Intracranial navigation of .088" large-bore catheters in MT appears technically feasible and safe. Larger prospective studies are warranted.

Predictors and prognoses of Willisian collateral failure during mechanical thrombectomy

During mechanical thrombectomy in the anterior cerebral circulation, thrombus embolization resulting in Willisian collateral failure may lead to critical stroke outcomes due to a shutdown of leptomeningeal collaterals. We hypothesized that the outcomes of dynamic Willisian collateral failure (DWF), induced during mechanical thrombectomy, would be associated with grave outcomes. We evaluated this hypothesis in consecutive patients, between January 2011 and May 2016, who underwent mechanical thrombectomy for anterior circulation occlusions, with an onset-to-puncture of 24 h. Patients with initial Willisian collateral failure (IWF) were identified first, with remaining patients classified into the DWF and Willisian collateral sparing (WCS) groups. Comparative and multivariable analyses were performed to predict grave outcomes (3-month modified Rankin Scale score of 5–6). Among 567 patients, 37 were in the IWF group, 38 in the DWF group, and 492 in the WCS group. Compared to the WCS and DWF groups, the IWF group had a higher baseline National Institute of Health Stroke Scale score and lower Alberta Stroke Program Early CT Score. The prevalence of grave outcomes was similarly high in the IWF (48.6%) and DWF (47.4%) groups, but lower in the WCS group (22.0%; p < 0.001). IWF and DWF were independent risk factors for a grave outcome.

Large Artery Atherosclerotic Clots are Larger than Clots of other Stroke Etiologies and have Poorer Recanalization rates

OBJECTIVES

There is a paucity of knowledge in the literature relating to the extent of clot burden and stroke etiology. In this study, we measured the Extracted Clot Area (ECA) retrieved during endovascular treatment (EVT) and investigated relationships with suspected etiology, administration of intravenous thrombolysis and recanalization.

MATERIALS AND METHODS

As part of the multi-institutional RESTORE registry, the ECA retrieved during mechanical thrombectomy was quantified using ImageJ. The effect of stroke etiology (Large-artery atherosclerosis (LAA), Cardioembolism, Cryptogenic and other) and recombinant tissue plasminogen activator (rtPA) on ECA and recanalization outcome (mTICI) was assessed. Successful recanalization was described as mTICI 2c-3.

RESULTS

A total of 550 patients who underwent EVT with any clot retrieved were included in the study. The ECA was significantly larger in the LAA group compared to all other etiologies. The average ECA size of each etiology was; LAA=109 mm², Cardioembolic=52 mm², Cryptogenic=47 mm² and Other=52 mm² (p=0.014*). LAA patients also had a significantly poorer rate of successful recanalization (mTICI 2c-3) compared to all other etiologies (p=0.003*). The administration of tPA was associated with a smaller ECA in both LAA (p=0.007*) and cardioembolic (p=0.035*) groups.

CONCLUSION

The ECA of LAA clots was double the size of all other etiologies and this is associated with a lower rate of successful recanalization in LAA stroke subtype. rtPA administration prior to thrombectomy was associated with reduced ECA in LAA and CE clots.

Choosing an Effective and Safe Direct Aspiration Setup for Tortuous Anatomy in Acute Ischemic Stroke: In vitro Study in a Physiological Flow Model

PURPOSE

 A direct aspiration first pass technique (ADAPT) is an effective thrombectomy option in patients with acute ischemic stroke. Balloon guide catheters (BGC) seem to improve the efficacy of stent retrievers and ADAPT. The last generation 6F aspiration catheters require 9F BGCs, which are rigid devices that are challenging to position in a tortuous anatomy. In this experimental study the efficacy of 6F ADAPT alone and 5F ADAPT combined with 8F BGC was evaluated.

MATERIALS AND METHODS

 Either a fibrin rich (white) clot or an RBC rich (red) clot was placed in the M1 segment of a transparent silicon phantom. Physiological hemodynamic conditions were maintained. The clots were retrieved by 6F aspiration catheter via 8F long sheath or 5F aspiration catheter via a flexible 8F BGC. Thrombectomy was performed under direct visual control. The primary endpoints were the number of passes and the number of distal emboli.

RESULTS

 Ten experiments were made with each clot model and thrombectomy technique (n = 40). Full recanalization could be achieved in every experiment. First pass mTICI 3 could be achieved by 6F ADAPT in 80 % of red clots and 90 % of white clots. Distal emboli were caused in 10 % and 20 %, respectively. When using 5F ADAPT combined with BGC, a first pass mTICI 3 rate of 90 % in red clots and 100 % in white clots could be achieved. A 10 % rate of distal emboli occurred in both groups. In almost all experiments (both techniques), the thrombi clogged the aspiration catheter. No statistically significant differences could be found between the techniques and clot models.

CONCLUSION

 6F ADAPT without BGC was as effective as 5F ADAPT combined with a flexible 8F BGC, with both techniques showing high first-pass recanalization rates and low distal emboli rates. Especially in the case of a tortuous anatomy, these setups should be considered as alternatives to a rigid 9F BGC. The thrombus compositions seemed to be irrelevant in this setting.

KEY POINTS

  · 6F ADAPT with no BGC and 5F ADAPT with BGC were very effective and performed equally.. · Both techniques should be considered in tortuous anatomy.. · In this setting the clot composition showed no effect on the recanalization rate..

CITATION FORMAT

· Madjidyar J, Nerkada L, Larsen N et al. Choosing an Effective and Safe Direct Aspiration Setup for Tortuous Anatomy in Acute Ischemic Stroke: In vitro Study in a Physiological Flow Model. Fortschr Röntgenstr 2021; 193: 544 - 550.

A direct aspiration first-pass technique (ADAPT) versus stent retriever for acute ischemic stroke (AIS): a systematic review and meta-analysis

BACKGROUND AND PURPOSE

There is an ongoing debate about whether a direct aspiration first-pass technique (ADAPT) or stent retriever should be used as the first-pass mechanical thrombectomy device for patients with acute ischemic stroke (AIS). This meta-analysis aimed to compare the safety and efficacy of ADAPT versus stent retriever in patients with AIS.

METHODS

Structured searches on the PubMed, Embase, and Cochrane Library databases were conducted through July 2020. The primary outcomes of this study were: successful and complete recanalization; excellent and favorable outcomes; all-cause mortality at 90 days; and symptomatic intracerebral hemorrhage (sICH). The secondary outcomes of this study were: successful recanalization by primary chosen device; additional therapy; occurrence of emboli in a new territory; hemorrhagic complication; hemorrhagic infarction; parenchymatous hematoma; and subarachnoid hemorrhage. The odds ratios (ORs) with 95% confidence intervals (CIs) of the primary and secondary outcomes were calculated using a random-effects model. I² statistics were used to assess the heterogeneity for each outcome among the included studies.

RESULTS

Finally, 20 studies with a total of 6311 patients were included in our meta-analysis. There were no significant differences between the ADAPT group and the stent retriever group of the primary and secondary outcomes except additional therapy. Our pooled results indicated that patients in the ADAPT group needed more additional therapy than those in the stent retriever group (OR 2.24, 95% CI 1.41-3.57).

CONCLUSION

In conclusion, our meta-analysis showed similar clinical outcomes of ADAPT and stent retriever. However, patients in the ADAPT group had higher additional therapy rates than those in the stent retriever group. Due to several inevitable limitations of this meta-analysis, more large-scale randomized controlled trials are required to further investigate this topic.

Efficacy of beveled tip aspiration catheter in mechanical thrombectomy for acute ischemic stroke

Background

Direct aspiration thrombectomy techniques use large bore aspiration catheters for mechanical thrombectomy. Several aspiration catheters are now available. We report a bench top exploration of a novel beveled tip catheter and our experience in treating large vessel occlusions (LVOs) using next-generation aspiration catheters.

Methods

A retrospective analysis from a prospectively maintained database comparing the bevel shaped tip aspiration catheter versus non-beveled tip catheters was performed. Patient demographics, periprocedural metrics, and discharge and 90-day modified Rankin Scale (mRS) scores were collected. Patients were divided into two groups based on which aspiration catheter was used.

Results

Our data showed no significant difference in age, gender, IV tissue plasminogen activator administration, admission NIH Stroke Scale score, baseline mRS, or LVO location between the beveled tip and flat tip groups. With the beveled tip, Thrombolysis in Cerebral Infarction (TICI) 2C or better recanalization was more frequent overall (93.2% vs 74.2%, p=0.017), stent retriever usage was lower (9.1% vs 29%, p=0.024), and patients had lower mRS on discharge (median 3 vs 4, p<0.001) and at 90 days (median 2 vs 4, p=0.008).

Conclusion

Patients who underwent mechanical thrombectomy with the beveled tip catheter had a higher proportion of TICI 2C or better and had a significantly lower mRS score on discharge and at 90 days.

A Child with Paradoxical Cerebral Embolism in Whom Mechanical Thrombectomy Led to a Favorable Outcome

Objective

We report a case of paradoxical cerebral embolism caused by patent foramen ovale (PFO) that was treated by the direct aspiration first pass technique (ADAPT).

Case Presentation

The case involved a 12-year-old boy who had symptoms of dizziness and vomiting the day prior to being admitted to the emergency department. The following morning, consciousness disorder, dysarthria, and right paresis were observed, and he was transferred to our hospital. Computed tomography (CT) and magnetic resonance imaging (MRI) lead to the diagnosis of acute cerebral infarction due to basilar artery (BA) occlusion. Mechanical thrombectomy was performed, and Thrombolysis in Cerebral Infarction (TICI) 3 was obtained. Postoperatively, his consciousness was improved, but echocardiography revealed PFO. Percutaneous PFO closure was performed at our department of pediatric cardiology.

Conclusion

For our patient with paradoxical cerebral embolism of the BA caused by PFO more than 6 hours after onset, mechanical thrombectomy with ADAPT using a Penumbra 5MAX ACE68 resulted in a good outcome.

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

BACKGROUND

First-pass efficacy (FPE) is an established marker of technical and clinical efficacy among mechanical thrombectomy (MT) techniques. It is unclear what the optimal approach is in achieving FPE. We present a single-center experience comparing rates of FPE among 2 MT techniques and evaluate the potential predictors of FPE among other outcomes.

METHODS

A single-center retrospective analysis was carried out of patients with consecutive large-vessel occlusion strokes (LVOS) of anterior circulation from September 2015 to April 2019 who underwent MT and for whom data were available on the status of FPE. Four MT techniques were identified: ADAPT (a direct first-pass aspiration), SrADAPT (stent retriever with aspiration), SRBG (stent retriever with balloon guide catheter), and STRAP (stent retriever-aspiration and proximal flow arrest). The primary outcome was FPE and secondary outcomes included the rate of successful reperfusion.

RESULTS

Among 226 patients with LVOS of the anterior circulation who underwent MT, data were available for 164 on FPE for the 4 MT techniques. SRBG was the most prevalent technique. No significant difference was found in rates of FPE among the 4 MT techniques (P = 0.332). No independent predictors of FPE were identified on multivariable analysis. STRAP had the highest rate of successful reperfusion compared with the other techniques (P = 0.049) and was the only independent predictor of that outcome (P = 0.027).

CONCLUSIONS

Among patients with LVOS of the anterior circulation, the rate of FPE did not differ among the 4 MT techniques. There were no predictors of FPE among the studied variables. STRAP was the only predictor of successful reperfusion.

Preclinical evaluation of Millipede 088 intracranial aspiration catheter in cadaver and in vitro thrombectomy models

Background

Larger bore aspiration catheters are expected to significantly improve the speed and completeness of acute stroke revascularization.

Objective

To evaluate the navigability and clot retrieval performance of a novel 8Fr aspiration catheter, Millipede 088 (Perfuze Ltd), using fresh-frozen cadavers and an in vitro thrombectomy model, respectively.

Methods

Cadaveric study: Transfemoral catheterization of the intracranial arteries was performed in six cadavers, allowing evaluation of navigation to 12 middle cerebral arteries (MCAs) and six basilar arteries. Commercially available 6Fr aspiration catheters (SOFIA Plus, Microvention) were used as controls. In vitro study: Three human blood clot phenotypes were created; red blood cell-rich, mixed, and fibrin/platelets-rich. Two clot sizes, resulting in occlusion of the internal carotid artery (ICA) and MCA-M1 were investigated. Endpoints were first-pass effect (FPE), first-pass complete ingestion, and second-pass recanalization.

Results

Cadaveric study: Both the Millipede 088 and SOFIA Plus devices reached the distal MCA-M1 and the basilar artery in 10/12 and 2/2 of the navigation attempts, respectively. In the two instances of unsuccessful navigation, neither device was able to cross the ophthalmic artery. In vitro study: In 10 mm long M1 occlusions, Millipede 088 achieved 100% FPE versus 40% for 6Fr devices (p>0.001). In 20 mm long ICA occlusions, Millipede 088 achieved 100% removal success within two passes in each clot phenotype compared with an average of 27% for 6Fr devices (p>0.001).

Conclusions

Navigation of the Millipede 088 catheter to the MCA-M1 and basilar artery is feasible in a cadaver model. Millipede 088 demonstrates superiority over 6Fr aspiration catheters for three representative clot phenotypes at the most common sites of occlusion in an in vitro vasculature model.

Use of intracranial stent as rescue therapy after mechanical thrombectomy failure-9-year experience in a comprehensive stroke centre

PURPOSE

There is no established rescue treatment in patients with mechanical thrombectomy (MT) failure. Our aim is to analyse whether the use of an intracranial stent improves prognosis in these patients.

METHODS

Retrospective analysis of a prospective cohort of patients with ischemic stroke due to middle cerebral artery occlusion (MCA) or distal intracranial carotid artery (ICA) occlusion, from September 2009 to April 2019 in our comprehensive stroke care centre. Patients with MT failure were identified and dichotomized into two groups according to whether or not an intracranial stent was implanted. We analysed clinical outcomes in both groups.

RESULTS

There was MT failure in 60 patients (14%) of the 433 with large vessel occlusion in distal ICA and proximal MCA. A stent was placed in 20 of them (33.3%). Compared to patients without rescue stenting, they showed better rates of independence at 3 months (mRS ≤ 2) 45% vs 2.5% (p < 0.001) and lower mortality 15% vs 50% (p = 0.009), maintaining statistical significance after multivariate analysis, without a significant increase of the rate of symptomatic intracranial haemorrhage (p = 0.209).

CONCLUSION

Placement of an intracranial stent as rescue therapy after MT failure was associated with better clinical outcome without significant increase in haemorrhagic complications. We believe that this procedure should be appraised in these patients.

Ballast and NeuronMax in stroke thrombectomy

BACKGROUND

Comparative evaluation of long sheath performance in stroke thrombectomy has not been performed.

OBJECTIVE

To review an initial experience with the new Ballast 6F long sheath compared with the NeuronMax, to evaluate comparative benchmarks in trackability, navigability, and procedural outcomes.

METHODS

A prospectively maintained thrombectomy database was evaluated over a 6-month period to compare procedural and angiographic results between a cohort of patients treated with the historical institutional standard long sheath (NeuronMax) and another with the new Ballast long sheath via a transfemoral approach.

RESULTS

Of 156 stroke thrombectomy cases, 69 were performed using NeuronMax and 40 using Ballast via a transfemoral approach; the remainder of cases employed alternative long sheaths or were performed via initial radial access. There was no significant difference in patient age, medical history, baseline National Institutes of Health Stroke Scale score, Alberta Stroke Program Early CT Score, arch type, tissue plasminogen activator use, and clot location between the two groups. Single-pass case frequency (41% for NeuronMax vs 44% for Ballast, p=0.84), and final successful revascularization (TICI 2b or greater) were similar between the two cohorts (91% vs 98%, p=0.42). Good 90-day outcome (modified Rankin Scale score 0-2) was also similar (33% for NeuronMax, 43% for Ballast, p=0.41). Excluding tandem occlusions, mean procedural time was 31 min for NeuronMax and 25 min for Ballast (p=0.09). Puncture to long sheath access and angiography in the base target vessel was faster for Ballast than NeuronMax (6.5 min vs 9.2 min, p=0.04).

CONCLUSION

Among a cohort of practitioners with historical, preferential experience with NeuronMax for stroke thrombectomy, faster procedural times were achieved with Ballast with similar final angiographic results.

Direct aspiration stroke thrombectomy: a comprehensive review

Mechanical thrombectomy is now the standard of care for acute ischemic stroke patients with large vessel occlusions, and can be performed with several devices and techniques. One of these techniques, direct aspiration (DA), consists of navigating a large-bore catheter up to the face of the clot and initiating forceful suction. This comprehensive review has three objectives: (1) to describe the direct aspiration technique; (2) to present the available evidence regarding predictive factors of DA success and performance compared with other techniques; and (3) to discuss the forthcoming improvements in distal aspiration.

Mechanical Thrombectomy: Answering Unanswered

The stroke physician community witnessed a major “breakthrough” in acute stroke therapeutics when the results of the first of the many positive trials, “MR CLEAN,” were published showing a significant absolute benefit in favor of mechanical thrombectomy in patients with large vessel occlusion (LVO). Thereafter, the investigators of ESCAPE, SWIFT PRIME, REVASCAT, THRACE, and PISTE concluded the same. Based on the initial studies, the American Stroke Association amended the 2013 guidelines in 2015 to include mechanical thrombectomy as the standard of care in patients with LVO presenting within six hours. In the past year, the horizon was further expanded when two major landmark trials, DAWN and DEFUSE 3, established the benefit of mechanical thrombectomy in the delayed window period in a select group of patients. It further led to the inclusion of the delayed window period treatment strategies in the 2018 guidelines. However, there are many unanswered questions in scenarios like small deficit with LVO, borderline large core, wake-up stroke (WUS), tandem occlusion, imaging of choice, conscious sedation (CS) versus general anesthesia (GA), and choice of technique. In our review, we aim to answer these questions along with a schematic representation of current techniques used in stroke thrombectomy.

Initial experience with React 68 aspiration catheter

INTRODUCTION

We describe our initial experience with the React 68 catheter (Medtronic, Dublin, Ireland), an FDA-approved catheter designed for aspiration in cases of emergent large vessel occlusion, as compared with the ACE 68 catheter (Penumbra, Alameda, CA).

METHODS

This observational study followed consecutive patients treated with the React catheter over a seven-month period at a comprehensive stroke center. Use of the device was per discretion of the operator. Patient demographics, thrombectomy technique, reperfusion scoring, and disposition were assessed. Performance was compared with patients treated with the ACE 68 catheter over a comparable period.

RESULTS

We treated 47 patients using the React 68 catheter using either aspiration alone or a combination of aspiration and stent retriever technique. The catheter was used in a variety of circumstances including proximal and distal occlusions involving the anterior and posterior circulation. Modified TICI 2b-3 was achieved in 45 of the 47 patients. The React 68 was comparable to the ACE 68 by all performance measures.

CONCLUSION

The React 68 catheter is a large-bore reperfusion catheter with trackability suitable for use in direct aspiration for recanalization of emergent large vessel occlusion.

Direct aspiration for thrombectomy in ischemic stroke: Impact of dwell time

OBJECTIVE

To evaluate the impact of dwell time on the efficacy of the direct aspiration thrombectomy in ischemic stroke.

METHODS

The study is a review of our prospective cerebral thrombectomy database of subjects admitted from January to December 2017. We performed direct aspiration with 2 min dwell time as recommended by the manufacturer (group 1) and 5 min dwell time (group 2) between January-June and July-December, respectively. The primary outcome was successful reperfusion after the first pass defined as modified Thrombolysis in Cerebral Infarction scores 2 b/3.

RESULTS

Eighty-five patients had a cerebral thrombectomy by direct aspiration, 45 in group 1 and 40 in group 2. There was no statistically significant difference between the two groups but a trend toward a better modified Thrombolysis in Cerebral Infarction first pass 2 b/3 rate in group 2 (70% versus 48.8%, p = 0.06). Although not statistically significant (p = 0.07), the ratio of rescue therapy with stent retriever was higher in group 1 (40%) than in group 2 (22.5%). After all passes, modified Thrombolysis in Cerebral Infarction 2 b-3 was obtained in 82.2% (37/45) of cases in group 1 and in 90% (36/40) of cases in group 2. Among 76 patients (89.5%) with modified Rankin Scale assessment at three months, no significant difference (p = 0.3) was found in the proportion of functionally independent individuals between groups 1 and 2 (51.8% versus 55.6%, respectively).

CONCLUSION

Although statistical significance was not reached, our retrospective analysis exhibited a strong trend toward modified Thrombolysis in Cerebral Infarction first pass improvement when dwell time was increased from 2 to 5 min.