Initial Experience in Direct Aspiration Thrombectomy Using a Novel 0.071-Inch Aspiration Catheter

FreeClimb 88 catheter with Tenzing 8 delivery for contact aspiration mechanical thrombectomy of anterior circulation large vessel occlusions

PURPOSE

Contact aspiration mechanical thrombectomy (CAMT) with 0.088-inch catheters may improve first-pass success rates, but delivery of such catheters can be challenging and limit effectiveness. This study examines the initial multicenter experience using the FreeClimb 88 catheter paired with the Tenzing 8 delivery catheter.

MATERIALS AND METHODS

Retrospective analysis was performed of consecutive patients with large vessel occlusion (LVO) of the internal carotid artery (ICA) or M1 segment of the middle cerebral artery treated with off-label CAMT using the FreeClimb 88 and Tenzing 8 at eight sites participating in the early limited release for these devices. Demographic and procedural variables were collected and analyzed with descriptive statistics and multivariable analysis.

RESULTS

Fifty-three consecutive patients were treated. Large vessel occlusion was located in the ICA in 19/53 (35.8%) patients; 34/53 (64.2%) were in the M1 segment. FreeClimb 88 was successfully delivered to the site of occlusion in 50/53 (94.3%) of patients. First-pass TICI 2c or 3 was achieved with FreeClimb 88 delivered by Tenzing 8 in 36 (67.9%) cases. Among cases with successful FreeClimb 88 delivery 9/50 (18.0%) required additional smaller devices to perform thrombectomy of distal occlusions after recanalization of the initial LVO. No complications or symptomatic hemorrhages occurred following thrombectomy.

CONCLUSION

Contact aspiration mechanical thrombectomy performed for ICA or M1 LVOs using FreeClimb 88 delivered with Tenzing 8 was safe, effective, and efficient in this early experience, with first-pass TICI 2c or 3 was achieved in 68% of patients without procedural complications occurring in any cases.

In vitro testing of a funnel-tip catheter with different clot types to decrease clot migration in mechanical thrombectomy

BACKGROUND

Mechanical thrombectomy is the standard treatment for acute ischemic stroke in patients with large vessel occlusion and can be performed up to 24h after symptom onset. Despite high recanalization rates, embolism in new territories has been reported in 8.6% of the cases. Causes for this could be clot abruption during stent retrieval into the smaller opening of a standard distal access catheter, and antegrade blood flow via collaterals despite proximal balloon protection. A funnel-shaped tip with a larger internal diameter was developed to increase the rate of first-pass recanalization and to improve the safety and efficacy of mechanical thrombectomy.

METHODS

This in vitro study compared the efficacy of a funnel-shaped tip with a standard tip in combination with different clot compositions. Mechanical thrombectomy was performed 80 times for each tip, using two stent retrievers (Trevo XP ProVue 3/20 mm, 4/20 mm) and four different clot types (hard vs. soft clots, 0-24h vs. 72h aged clots).

RESULTS

Significantly higher first-pass recanalization rates (mTICI 3) were observed for the funnel-shaped tip, 70.0% versus 30.0% for the standard tip (absolute difference, 32; relative difference 57.1%; P < .001), regardless of the clot type and stent retriever. Recanalization could be increased using harder Chandler loop clots versus softer statically generated clots, as well as 0-24h versus 72h aged clots, respectively.

CONCLUSION

The funnel-shaped tip achieved higher first-pass recanalization rates than the smaller standard tip and lower rates of clot abruption at the tip. Clot compositions and aging times impacted recanalization rates.

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.

Improved catheter delivery for aspiration thrombectomy using Tenzing 7 ledge reducing catheter and FreeClimb 70

PURPOSE

Previous comparative mechanical thrombectomy device trials reported a substantial crossover rate from first-line aspiration to stent-retriever thrombectomy. A specialized delivery catheter may help track large-bore aspiration catheters to target occlusions. We report our multicenter experience of aspiration thrombectomy of intracranial large vessel occlusions using the FreeClimb^TM 70 and Tenzing® 7 delivery catheter (Route 92, San Mateo, CA).

METHODS

After local Institutional Review Board approval, we retrospectively reviewed the clinical, procedural, and imaging data of patients who underwent mechanical thrombectomy with the FreeClimb 70 and Tenzing 7.

RESULTS

FreeClimb 70 was successfully delivered using Tenzing 7 to target occlusion in 30/30 (100%) patients (18 M1, 6 M2, 4 ICA-terminus, and 2 basilar artery occlusions), without the use of a stent-retriever for anchoring. In 21/30 (70%) cases, a leading microwire was not needed to advance the Tenzing 7 to the target. Median (interquartile range) time from groin puncture to first pass was 12 (interquartile range 8-15) minutes. Overall first pass effect, or first pass effect (modified thrombolysis in cerebral ischemia 2C-3), was achieved 16/30 (53%). For M1 occlusions, first pass effect was 11/18 (61%). Successful reperfusion (modified thrombolysis in cerebral ischemia ≥ 2B) was achieved in 29/30 (97%) cases after a median of 1 pass (interquartile range 1-3). Median groin puncture to reperfusion time was 16 (interquartile range 12-26) minutes. There were no procedural complications or symptomatic intracranial hemorrhage. Average improvement in National Institutes of Health Stroke Scale at discharge was 6.6  ±  7.1. There were three patient deaths (renal failure, respiratory failure, and comfort care).

CONCLUSIONS

Initial data support the use of Tenzing 7 with FreeClimb 70 catheter for reliable access to rapid, effective, and safe aspiration thrombectomy of large vessel occlusions.

Aspiration thrombectomy of M2 middle cerebral artery occlusion to treat acute ischemic stroke: A core lab–adjudicated subset analysis from the COMPLETE registry and literature review

Background

Although the benefits of aspiration thrombectomy for treating acute ischemic stroke caused by proximal large vessel occlusion have been established, fewer data are available for evaluating aspiration thrombectomy of distal occlusion. The objective of this study was to evaluate, by means of prospectively collected data, the safety and efficacy of aspiration thrombectomy in patients with M2 middle cerebral artery (MCA) occlusion.

Methods

This study is a subset analysis of a global prospective multicenter observational registry that included patients who presented with either anterior or posterior large vessel occlusion and were eligible for mechanical thrombectomy using the Penumbra System including the Penumbra 3D Revascularization Device. For this analysis, all patients in the registry with M2 MCA occlusion were included.

Results

Of the 650 patients in the registry, 113 (17.4%) had M2 MCA occlusion. The rate of a modified treatment in cerebral infarction score of 2b to 3 after the procedure was 79.6% (90/113), the rate of a modified Rankin Scale score of 0–2 at 90 days was 72.5% (79/109), and the all-cause mortality rate at 90 days was 8.8% (10/113). Device-related serious adverse events occurred in one patient (0.9%) within 24 h and in two patients (1.8%) overall. Procedure-related serious adverse events occurred in four patients (3.5%) within 24 h and in six patients (5.3%) overall (nine events).

Conclusion

For appropriately selected patients, aspiration thrombectomy for acute ischemic stroke due to M2 MCA occlusion was safe and effective, with high rates of technical success and good functional outcome.

AXS Vecta 0.071-0.074 Inch Aspiration Catheters for Mechanical Thrombectomy: Case Series and Literature Review

Aspiration catheters are widely used for thrombectomy either alone or in combination with a stent-retriever, with a distal inner diameter and trackability keys to their success. In an illustrative case series, we report our clinical experience with AXS Vecta (Stryker Neurovascular, Fremont, CA, USA), available in both 0.071-inch and 0.074-inch distal inner diameters, including the first 2 Vecta 74 cases reported. A literature review on AXS Vecta is also provided. In our series, 9 thrombectomies were performed (Vecta 71: 2 M1, 5 M2 occlusions; Vecta 74: 1 M1 and 1 ICA-terminus occlusion). The AXS Vecta was successfully delivered to the target site in all cases. In 7 of 9 cases, the catheter was delivered over a Tenzing 7 delivery catheter (Route 92 Medical, San Mateo, CA, USA). For 2 of 9 combination approach cases, Vecta was delivered using the stent-retriever wire as a rail. The median improvement in NIHSS score during hospitalization was 9 (IQR 5-12). Successful mTICI 2C or 3 recanalization was achieved in 8 of 9 (89%) patients after a median 2 (IQR 1-2) passes. Our median groin-to-reperfusion time was 23 (IQR 12.5-32) minutes, with no procedural complications. Two previous clinical studies of a total of 29 patients treated with Vecta 71 reported successful mTICI 2b-3 recanalization in 89-90% of cases. The Median groin-to-reperfusion time was 30 minutes. Complications were seen in 2 of 29 (6.9%) cases (vessel perforation and/or intracerebral hemorrhage). These data support the efficacy, deliverability, and safety of AXS Vecta for mechanical thrombectomy.

Updates in mechanical thrombectomy

Stroke is a leading cause of morbidity and mortality. The advent of mechanical thrombectomy has largely improved patient outcomes. This article reviews the features and outcomes associated with aspiration, stent retrievers, and combination catheters used in current practice. There is also a discussion on clinical considerations based on anatomical features and clot composition. The reperfusion grading scale and outcome metrics commonly used following thrombectomy when a patient is still in the hospital are reviewed. Lastly, there are proposed discharge and outpatient follow-up goals in caring for patients hospitalized for a stroke.

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.

The Q and A-The MIVI Q Catheters for Aspiration Thrombectomy-Initial Experience from London

Background: Aspiration thrombectomy is a widely accepted treatment option for large vessel occlusion (LVO). The MIVI aspiration system has a novel design to maximize the lumen size. We present the results of our initial experience with this innovative aspiration thrombectomy system. Materials and Methods: Retrospectively, we reviewed our database to find all cases of LVO treated with the MIVI Q system (February 2019 and July 2020). In addition, we recorded the baseline demographics, NIHSS, ASPECT, mTICI scores, procedural time, complications, and 90 day mRS. Results: Herein, we identified 25 patients with an average age of 65.3 ± 19.3 years (range 19–89), majority of whom were female (n = 14, 56%). The average NIHSS was 16.9 ± 6.7 (range 6–30), and the average CT ASPECT was 7.9 ± 1.4 (range 5–10). The most common clot location was the M1 segment of the MCA (n = 16, 64%). Four of the patients had tandem lesions (16%). The average clot length was 21.7 ± 31 mm (range 2–130 mm). Of the 23 cases where the Q catheter reached the proximal clot face, mTICI ≥ 2b was achieved on the first pass in 11 cases (44%), and at the end of the ‘Q aspiration’ only the procedures with 16 patients achieved mTICI ≥ 2b recanalization (64%). Stent-retrievers were used in 13 cases (52%). At the end of the procedure, 24 patients (96%) achieved mTICI ≥ 2b with 18 patients (72%) achieving mTICI ≥ 2c. The average number of passes with the Q catheter, including when it was used for SOLUMBRA, was 2.1 ± 2.2 (range 1–10). The mean procedure time was 69 ± 32 mins (range 7–116 mins). No complications were associated with the MIVI Q. Conclusions: The MIVI aspiration system is a novel technology with regards to aspiration mechanical thrombectomy. The system is easy to use with early results comparable to other large-bore catheter systems. However, further studies are needed.

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.

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.