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

The NeVa stent-retriever - a single-centre real-world experience

Stent-retriever-based mechanical thrombectomy (MT) is an effective treatment for acute ischemic stroke (AIS) caused by large vessel occlusion (LVO). First-pass effect (FPE) is one most powerful predictors of positive outcomes in LVO AIS patients treated with MT. We performed an independent central reader review of our prospectively maintained database to identify all patients treated first with the NeVa stent retriever at our single high-volume Comprehensive Stroke Centre.Overall, 89 patients met our inclusion criteria. The median age was 73 yrs (range 28-88; 52% male). The median presentation NIHSS was 16 (range 5-30) and 49% received IV tPA prior to MT. 93% of target occlusions were in the anterior circulation (n = 83) with a median ASPECT score on plain CT of 8 (range 5-10). A Balloon Guide Catheter (BGC) was used in 80% of cases and a distal aspiration catheter was used in all cases. Longer NeVa models (≥29 mm) were used in 89% of cases. FPE was demonstrated in 57% of cases (eTICI score of ≥2c) with modified FPE demonstrated in 65.1% of cases (eTICI score of ≥2b (67%)). A final eTICI score of ≥2c was achieved in 87% of cases. Good functional outcome (mRS ≤2) was achieved in 40% of patients (n = 81).The NeVa stent-retriever has a very high rate of FPE and final recanalization in this real-world cohort of patients from the NeVa One registry. These results are higher than those previously published and may support longer NeVa device use with a BGC and proximal aspiration to optimize FPE.

The ASCEND Technique-A Modified Direct Aspiration First Pass Technique for a Faster and Cost-effective Mechanical Thrombectomy

PURPOSE

Direct aspiration first pass technique (ADAPT) has been the standard for aspiration thrombectomy (AT) in anterior circulation large vessel occlusion (AC-LVO) with modifications of the technique based on devices used and difficulties encountered. We introduce the ASCEND technique (Aspiration with Steam-shaped Catheter, Excluding additioNal Devices), and hypothesize that it improves catheter navigation, leading to time and cost savings in MT.

METHODS

This is a single institute, retrospective, pre-post intervention study, including consecutive patients with AC-LVO who underwent AT as first-pass technique. Patients were divided into two groups based on the first-pass technique attempted (ASCEND vs conventional ADAPT). Baseline characteristics, primary outcomes (first pass time, total procedure time, total additional devices and device cost) and secondary outcomes (recanalization, complications) were compared between groups. Multiple linear regression models were built for primary outcomes to look for the effect of steam-shaping when covariates are present to reflect real-world setting. Multi-national survey performed to introduce the technique and feedback obtained.

RESULTS

ASCEND (n = 39) and cADAPT (n = 40) groups were similar in baseline clinical characteristics. Anterior genu and ophthalmic segment were crossed in 94.9%, clot reached in 84.6%, and entire MT procedure completed in 59.0% of patients of the ASCEND group without use of additional materials. Groups were similar in performance and safety indicators. ASCEND technique was superior to conventional ADAPT with less first-pass time (8.9 vs 14.7 min), total procedure time (20.2 vs 35.4 min), additional devices used (0 vs 3) and cost involved (2083 vs 5830 £) per procedure (all P < 0.05). Multiple linear regression models maintained improved primary outcomes with steam-shaping (all P < 0.05). Neurointerventionalists who tried ASCEND (n = 11) affirmed that it was safe and likely to save time and cost involved.

CONCLUSION

ASCEND technique, involving a simple step of steam-shaping the aspiration catheter during MT can provide huge benefits in time and cost savings, without compromise of performance or safety.

Inter-proceduralist variability in angiographic outcomes after stroke thrombectomy and the importance of quality over quantity of passes

BACKGROUND

Complete recanalization (CR, modified Treatment in Cerebral Ischemia (mTICI) score of 2c or better) is associated with favorable outcomes after endovascular thrombectomy (EVT) for stroke patients. However, the degree of inter-proceduralist differences in CR rates is unknown, and whether higher CR rates are being achieved by performing more passes or by focusing on first-pass effectiveness is also unclear.

METHODS

This was a multicenter retrospective study of anterior circulation large vessel occlusion stroke patients in the United States from 2016 to 2022. Patients treated by proceduralists with at least 50 cases were included. CR rates for each proceduralist were assessed and proceduralists were divided into tertiles. First-pass effect (FPE, defined as CR after one pass) and the number of passes for patients treated by the top tertile of proceduralists were compared with the bottom tertile. Mediation analyses were conducted to assess causal links between CR rates and number of passes or FPE.

RESULTS

A total of 1096 EVTs performed by 11 proceduralists were identified. CR rates were highly variable across providers (43.1% to 75.3%, p<0.001). Patients treated by the top tertile were more likely to experience FPE (OR 1.99, 95% CI 1.49 to 2.67, p<0.001) and did not undergo more passes (p=0.69) compared with the bottom tertile. Higher rates of FPE among patients was a significant mediator of higher odds of CR among patients treated by the top tertile (p<0.001).

CONCLUSIONS

Angiographic outcomes among EVT proceduralists are highly variable. Proceduralists who achieve higher rates of CR are doing so with higher rates of FPE, not more passes.

"The microcatheter contrast injection technique": A novel technique to detect the proximal end of a thrombus in mechanical thrombectomy

Background: An aspiration catheter needs to attach to a thrombus in order to achieve first-pass recanalization by mechanical thrombectomy (MT) for acute ischemic stroke (AIS), particularly that using a direct aspiration first pass technique. The meniscus sign, which is defined as meniscoid contrast opacification indicating the proximal edge of a thrombus, has been suggested to contribute to successful recanalization. In some cases, the meniscus sign is not detected following an injection of contrast medium through a guiding catheter. To precisely identify the location of a thrombus, we use "the microcatheter contrast injection (MCI) technique," which accurately shows the proximal edge of a thrombus. We herein introduce this novel technique and discuss its efficacy in MT. Methods: In cases without the meniscus sign, a microcatheter was advanced to the distal end of contrast opacification, and contrast medium was injected through the microcatheter to detect the meniscus sign. An aspiration catheter was then advanced to the thrombus indicated by the meniscus sign and slowly withdrawn under aspiration. Results: 29 patients underwent MT for AIS using the MCI technique. Even in cases without the meniscus sign on initial angiography, the MCI technique accurately revealed the proximal edge of the thrombus. Moreover, middle cerebral artery occlusion due to atherosclerotic stenosis and displacement of the aspiration catheter and thrombus axis were detected using this technique. Conclusions: The MCI technique may effectively reveal the exact site of a thrombus and increase the success rate of first-pass recanalization.

Placing the balloon-guide catheter in the high cervical segment of the internal carotid artery is associated with improved recanalization

BACKGROUND

Mechanical thrombectomy (MT) is part of the standard of care for stroke treatment, and improving its efficacy is one of the main objectives of clinical investigation. Of importance is placement of the distal end of balloon-guided catheters (BGC). We aim to determine if this influences outcomes.

METHODS

We analyzed data from the ASSIST Registry, an international, multicenter prospective study of 1492 patients. We divided patients treated with BGC according to the placement of the BGC: low cervical (LCG (the lower 2/3 of cervical internal carotid artery (ICA)) or high cervical (HCG (upper 1/3 of cervical ICA, petro-lacerum or higher)). We analyzed characteristics and outcomes overall and stratified on the primary MT technique: Stent-Retriever only (SR Classic), Combined use of aspiration catheter and SR (Combined), and Direct Aspiration (ADAPT).

RESULTS

Our study included 704 subjects -323 in the low cervical and 381 in the high cervical groups. Statistical differences were seen in the proportion of females and tandem lesions (both higher for LCG). Placing the BGC in the high cervical segment is associated with better recanalization rates (expanded treatment in cerebral infarction (eTICI) score of 2c-3) at the end of the procedure (P<0.0001) and shorter procedures (P=0.0005). After stratifying on the three primary techniques (SR Classic, Combined, and ADAPT), placing the BGC in the high segment is associated with a better first-pass effect (FPE), less distal emboli, and better clinical outcomes in the SR Classic technique.

CONCLUSIONS

Placing the distal end of the BGC at the high cervical segment or higher is associated with better recanalization.

Direct Aspiration Versus Combined Technique for Anterior Distal, Medium Vessel Occlusions Stroke: The JET Distal Vessel Occlusion Study

BACKGROUND AND OBJECTIVES

The optimal mechanical thrombectomy technique for distal, medium vessel occlusion (DMVO) stroke remains unknown. We aimed to compare the safety and efficacy of 2 thrombectomy first-line approaches, direct aspiration (DA), and combined technique (CT) in patients with DMVOs.

METHODS

We conducted a retrospective review of a prospectively collected multicenter database of patients with DMVOs (at or distal to M2 and A1), who underwent mechanical thrombectomy with JET D reperfusion catheters between January 2020 and December 2021. The primary end point was the rate of first-pass complete recanalization, defined as modified treatment in cerebral infarction (mTICI) 3. The hemorrhagic complications, the 90 days functional independence rate (modified Rankin Scale 0-2), and mortality were also evaluated.

RESULTS

A total of 171 consecutive patients were enrolled (95 in DA and 76 in CT cohort). The 2 groups had comparable demographics and baseline characteristics. The DA group had a higher rate of first-pass effect (40.0% vs 10.5%, P < .001), final mTICI 2b-3 (89.5% vs 71.1%, P = .003) and final mTICI 3 (58.9% vs 28.9%, P < .001), shorter groin to reperfusion time (65 ± 43 min vs 101 ± 60 min, P < .001), and higher rate of 90-day functional independence (63.7% vs 36.1%; P = .001) compared with the CT group. There were no significant differences in hemorrhagic complications between the 2 groups. The DA group showed a lower rate of 90-day mortality (9.9% vs 27.8%; P = .004).

CONCLUSION

In patients with DMVOs, DA with a distal dedicated reperfusion catheter appears to demonstrate better safety and efficacy when compared with the CT using the same catheter.

Effect of Intravenous Tirofiban Versus Placebo on First-Pass Successful Reperfusion in Endovascular Stroke Thrombectomy: Insights From the RESCUE BT Randomized Clinical Trial

BACKGROUND

First-pass successful reperfusion (FPSR), defined as a successful/complete reperfusion achieved after a single thrombectomy pass, is predictive of favorable outcome in patients with acute ischemic stroke with large-vessel occlusion. It is unknown whether intravenous tirofiban is effective in increasing the rate of FPSR in acute anterior large-vessel occlusion stroke.

METHODS AND RESULTS

Patients who had acute large-vessel occlusion stroke presenting within 24 hours and underwent endovascular thrombectomy were analyzed from the RESCUE BT (Intravenous Tirofiban for Patients With Large Vessel Occlusion Stroke) clinical trial, of which the main analysis was neutral. The RESCUE BT trial randomized patients to receive either intravenous tirofiban or placebo before endovascular thrombectomy. The primary end point was FPSR, defined as successful reperfusion (extended thrombolysis in cerebral infarction scale 2b50, 2c, or 3) at first thrombectomy attempt. A modified Poisson regression analysis assessed the association between intravenous tirofiban treatment and FPSR. Of 948 enrolled patients, 463 patients were randomized to the tirofiban group and 485 to the placebo group. The mean age was 67 years, and 41.0% of the patients were women. FPSR was achieved more often in the tirofiban group (30.5% versus 23.5%; adjusted risk ratio, 1.24 [95% CI, 1.01-1.51]; P=0.04). FPSR was associated with a favorable shift to lower modified Rankin Scale disability levels at 90 days (common odds ratio, 1.42 [95% CI, 1.08-1.86]; P=0.01).

CONCLUSIONS

In this post hoc analysis of the RESCUE BT trial, treatment with intravenous tirofiban before endovascular thrombectomy was associated with increased FPSR in patients with acute ischemic stroke due to large-vessel occlusion in the anterior circulation. FPSR was associated with reduced 90-day levels of disability.

REGISTRATION

URL: http://chictr.org; Unique Identifier: ChiCTR-INR-17014167.

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 evaluation of how the presence of the stent retriever and microcatheter influences aspiration parameters in thrombectomy according to their position inside the aspiration catheter

BACKGROUND

Several variations of the combined thrombectomy technique for acute ischemic stroke using a stent retriever and aspiration catheter have been described. The aim of our study was to assess how the presence of the microcatheter and stent retriever affect the basic aspiration parameters, namely, flow rate and aspiration force, depending on their position within the aspiration catheter.

METHODS

Two experimental set-ups were designed to assess changes in flow rate and aspiration force according to the position of the stent retriever and microcatheter within the aspiration catheter.

RESULTS

The transition of the stent retriever and microcatheter from the distal to proximal position resulted in a progressive increase in the flow rate, but with no impact on aspiration force. Additionally, the size of the stent retriever had no significant effect on flow rate changes and the reduction in flow rate was related to the microcatheter diameter. Negative pressure generated inside the aspiration catheter impacted on its distal segment located beyond the radiopaque marker, thus leading to its partial collapse. As a consequence, the measured aspiration force was lower than the theoretical aspiration force level for all tested aspiration catheters.

CONCLUSIONS

In our experimental model, the position of the stent retriever and microcatheter within the aspirator catheter affected the flow rate, but not the aspiration force. Negative pressure generated within the aspiration catheter appeared to determine a partial collapse of the distal segment that resulted in a less effective aspiration force than the theoretical aspiration force level.

Learning Curve Effect of Combined Technique Thrombectomy as First-Line Attempt for Acute Ischemic Stroke: A Single-Center Retrospective Study

OBJECTIVES

We retrospectively examined the initial experience and learning curve after the introduction of thrombectomy with the combined technique using an aspiration catheter and a stent retriever as first-line attempt for acute ischemic stroke.

METHODS

Consecutive patients undergoing thrombectomy for acute ischemic stroke at our institution between January 2020 and December 2022 were divided into 3 groups according to the year of thrombectomy. Patient characteristics and procedural, safety, and clinical outcomes were compared between the three year periods to determine predictors of favorable clinical outcome.

RESULTS

In 2020, 2021, and 2022, the numbers of patients were 74, 70, and 90, respectively, with similar patient characteristics across the three years; successful recanalization rates were 79.7%, 97.1%, and 93.3%, respectively (P < 0.01 for the first 2 years); median procedure times were 67, 43, and 32 minutes, respectively (P < 0.01 for the first 2 years and P = 0.018 for the last 2 years); first pass effect rates were 20.3%, 41.4%, and 44.4%, respectively (P < 0.01 for the first 2 years); symptomatic intracranial hemorrhage rates were 14.9%, 2.9%, and 1.1%, respectively (P = 0.018 for the first 2 years); and percentages of modified Rankin Scale score 0-2 at 90 days were 24.3%, 42.9%, and 41.1%, respectively (P = 0.022 for the first 2 years). Procedure time (P = 0.038) and successful recanalization (P = 0.041) were independent predictors of favorable clinical outcome.

CONCLUSIONS

The learning curve effect of the combined technique may be associated with better clinical outcome due to increased successful recanalization rates, shortened procedure time, and reduced symptomatic intracranial hemorrhage.

Improving the Reachability of Contact Aspiration for Acute Ischemic Stroke Using a New Delivery Assist Catheter

OBJECTIVE

This study aimed to improve the reachability of large lumen catheter for contact aspiration during acute ischemic stroke by a new delivery assist catheter.

METHODS

This study included 58 patients with large-vessel stroke treated using endovascular procedures at our institution and affiliated hospitals between July 2021 and January 2023. Contact aspiration, especially contact aspiration using nonpenetrating of thrombus (CANP) technique, was adopted as first-line thrombectomy for localized internal carotid artery, middle cerebral artery proximal (M1 segment), and basilar artery without tandem occlusion in acute stroke. The new delivery assist catheter (AXS Offset catheter, Stryker, Fremont, CA, USA) was standardized after its release. Results of this improved contact aspiration technique using the new delivery assist catheter, including reachability, procedure time, and first-pass effect, were compared with conventional catheters.

RESULTS

Of the 58 patients, 43 underwent only thrombectomy for acute embolic stroke. CANP technique was attempted on 25 patients (25/43, 58.1%). Of these, a normal inner catheter (inner diameter: 0.021 or 0.027 inches) and the new delivery assist catheter were used on 10 (10/25, 40%) and 15 (15/25, 60%) patients, respectively. An aspiration catheter reached the thrombus for 5 patients (5/10, 50%) and 14 patients (14/15 93.3%) in the normal and new delivery assist catheter groups, respectively (P = 0.023). There was no significant difference in the results of contact aspiration due to the delivery catheter.

CONCLUSIONS

The new delivery assist catheter improved the reachability of the aspiration catheter to the thrombus and is an effective device for performing CANP technique.

The Aristotle 18 and 24 microwires in neuroIntervention: Early experience at a single centre

BACKGROUND

Current neurointerventional procedures are expanding the use of large bore microcatheters, of up to 0.033" inner diameters, to accommodate intrasaccular flow disruptors or neck-bridging devices, including flow diverters. The use of large bore microwires may mitigate the ledge gap between wire and catheter, facilitate navigation and offer support in distal tortuous anatomy. We aim to report our early experience using the novel Aristotle (Scientia Vascular, West Valley City, UT) 18 and 24 microwires in neurovascular interventions.

METHODS

We analysed neurointerventional procedures in which the Aristotle 18 and 24 microwires were used at a single centre. Prospectively collected data, from March 2022 to February 2023, including patient's clinical outcome (successful target vessel, aneurysm catheterisation, peri-procedural complications (thromboembolic, haemorrhagic, vessel dissection or perforation) were analysed.

RESULTS

Overall, the use of Aristotle 18 and 24 microwires was recorded in 84 neurointerventional procedures during the study period, including endovascular aneurysm treatment (n = 30), endovascular thrombectomy (n = 46), dural venous sinus manometry/stent placement (n = 7), and extracranial carotid artery stent placement (n = 1). The Aristotle 18 microwire was used in conjunction with 0.021" microcatheters and the Aristotle 24 microwire with the 0.027 or 0.033" microcatheters. In all cases (100%), the target vessel or aneurysm was reached with the microwire, allowing seamless advancement of the selected microcatheters. No procedure related complications were recorded.

CONCLUSIONS

The use of the Aristotle 18 and 24 microwires in neurointerventional procedures is feasible and safe. The microwires provide reduced ledge gap, improved torquability, support and safety over standard 0.014" microwires.

Partial (SAVE) versus Complete (Solumbra) Stent Retriever Retraction Technique for Mechanical Thrombectomy: A Randomized In Vitro Study

BACKGROUND AND PURPOSE

Mechanical thrombectomy has become a first-line treatment for acute ischemic stroke. Several techniques combining stent retrievers and distal aspiration catheters have been described. We aimed to characterize the efficacy of 2 commonly used techniques according to clot characteristics.

MATERIALS AND METHODS

Soft (mean stiffness = 95.77 [SD, 5.80] kPa) or stiff (mean stiffness = 205.63 [SD, 6.70] kPa) clots (3 × 10 mm and 2 × 10 mm, respectively) were embolized to the distal M1 segment of the MCA in an in vitro model. The technique was randomly allocated (1:1): stent retriever assisted vacuum-locked extraction (SAVE) versus complete retraction (Solumbra). The primary end point was the percentage of first-pass recanalization. Secondary end points were periprocedural distal embolization measures.

RESULTS

A total of 130 mechanical thrombectomies were performed (50 for soft clots and 15 for stiff clots per arm). Overall, the rate of first-pass recanalizaton was 35% with Solumbra and 15% with SAVE (P < .01). For stiff clots, the first-pass recanalizaton was equal for both methods (27%; P = 1.00). With soft clots, the first-pass recanalizaton was higher with Solumbra (38%) than with SAVE (12%; P < .01). When we used soft clots, the maximum embolus size (mean, 1.19 [SD, 0.9] mm versus 2.16 [SD, 1.48] mm; P < .01) and total area of emboli (mean, 1.82 [SD, 2.73] versus 3.34 [SD, 3.2]; P = .01) were also lower with Solumbra than with SAVE.

CONCLUSIONS

Clot characteristics may influence the efficacy of the thrombectomy technique. In occlusions caused by soft clots, complete retrieval into the distal aspiration catheters achieved higher rates of first-pass recanalizaton and lower embolization.

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.

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

BACKGROUND

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

HYPOTHESIS

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

METHODS

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

OUTCOMES

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

DISCUSSION

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

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.

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.

Comparison of a direct aspiration first pass technique vs. stent retriever thrombectomy for the treatment of acute large vessel occlusion stroke in the anterior circulation with atrial fibrillation

Objectives

The stent retriever thrombectomy (SRT) and a direct aspiration first-pass technique (ADAPT) are the two main mechanical thrombectomy (MT) techniques for acute ischemic stroke. Few data are available for comparing the therapeutic effects associated with the two mechanical thrombectomy techniques in acute ischemic stroke with atrial fibrillation. The purpose of this study was to compare the efficacy and safety of both techniques for the treatment of acute large vessel occlusion stroke in the anterior circulation with atrial fibrillation.

Methods

Retrospective analysis was performed in stroke patients with atrial fibrillation admitted to Guangzhou Red Cross Hospital from January 2018 to June 2022 who received mechanical thrombectomy by either SRT or ADAPT. Comparisons were made with regards to the initial traits, course of therapy, effectiveness indicators, and complications of these individuals. The primary outcome is recanalization rate.

Results

In this study, after screening 431 patients, 92 eligible patients, with 48 patients received SRT and 44 patients received ADAPT, were included. There was no significant difference in the recanalization rate between the two groups (SRT 87.5% vs. ADAPT 84.1%, P = 0.639). Compared with SRT, patients in ADAPT group had a shorter puncture to recanalization time [33.5 min (27.0-59.5) vs. 50.5 min (31.5-91.5), P = 0.009], a higher first pass success recanalization rate (54.5 vs. 33.3%, p = 0.040), and a higher rate of patients with improvement of NIHSS scores ≥4 at discharge (84.1 vs. 56.3%, P = 0.004). However, distal embolization occurred more frequently in the ADAPT group than that in SRT group (50.0 vs. 22.9%, P = 0.007). There was no significant difference between the two groups in the 3-month mRS score, symptomatic cerebral hemorrhage, or mortality.

Conclusions

Compared with SRT, ADAPT has similar recanalization rate for the treatment of acute large vessel occlusion stroke in the anterior circulation with atrial fibrillation. However, ADAPT might be more effective in terms of shorter puncture to recanalization time and higher first pass success recanalization rate. Further studies are needed for confirming our results.

Aspiration versus stent retriever for posterior circulation stroke: A meta-analysis

AIMS

New thrombectomy strategies have emerged recently. Differences between posterior circulation stroke management via aspiration and stent retriever remain to be evaluated. We compared the safety and efficacy of aspiration and stent retriever in treating posterior circulation stroke.

METHODS

Three databases (PubMed, Embase, and Cochrane Library) were systematically searched for studies comparing aspiration and stent retriever in patients with posterior circulation stroke. The modified Newcastle-Ottawa scale was used to assess the risk of bias. A random-effects model was used.

RESULTS

Fifteen cohort studies with 1451 patients were included. Pooled results showed a significant difference in total complication (odds ratio [OR] 0.48, 95% confidence interval [CI] [0.30, 0.76], p = 0.002). successful recanalization (1.85, [1.30, 2.64], p = 0.0006), favorable outcome (1.30, [1.02, 1.67], p = 0.04), procedure duration (-22.10, [-43.32, -0.88], p = 0.04), complete recanalization (4.96, [1.06, 23.16], p = 0.009), and first-pass effect (2.59, [1.55, 4.32], p = 0.0003) between the aspiration and stent retriever groups, and in favor of aspiration. There was no significant difference in the outcomes of rescue therapy (1.42, [0.66, 3.05], p = 0.37) between the two groups.

CONCLUSION

Patients with posterior circulation stroke receiving treatment with aspiration achieved better recanalization, first-pass effect, and shorter procedure time. Aspiration may be more secure than a stent retriever.

A Review of the Advancements in the in-vitro Modelling of Acute Ischemic Stroke and Its Treatment

In-vitro neurovascular models of large vessel occlusions (LVOs) causing acute ischemic stroke (AIS) are used extensively for pre-clinical testing of new treatment devices. They enable physicians and engineers to examine device performance and the response of the occlusion to further advance design solutions for current unmet clinical needs. These models also enable physicians to train on basic skills, to try out new devices and new procedural approaches, and for the stroke team to practice workflows together in the comfort of a controlled environment in a non-clinical setting. Removal of the occlusive clot in its entirety is the primary goal of the endovascular treatment of LVOs via mechanical thrombectomy (MT) and the medical treatment via thrombolysis. In MT, recanalization after just one pass is associated with better clinical outcomes than procedures that take multiple passes to achieve the same level of recanalization, commonly known as first pass effect (FPE). To achieve this, physicians and engineers are continually investigating new devices and treatment approaches. To distinguish between treatment devices in the pre-clinical setting, test models must also be optimized and expanded become more nuanced and to represent challenging patient cohorts that could be improved through new technology or better techniques. The aim of this paper is to provide a perspective review of the recent advancements in the in-vitro modeling of stroke and to outline how these models need to advance further in future. This review provides an overview of the various in-vitro models used for the modeling of AIS and compares the advantages and limitations of each. In-vitro models remain an extremely useful tool in the evaluation and design of treatment devices, and great strides have been made to improve replication of physiological conditions. However, further advancement is still required to represent the expanding indications for thrombectomy and thrombolysis, and the generation of new thrombectomy devices, to ensure that smaller treatment effects are captured.

Simplified classification of cavernous internal carotid artery tortuosity: a predictor of procedural complexity and clinical outcomes in mechanical thrombectomy

OBJECTIVES

Thromboaspiration catheters are increasingly used for the endovascular treatment of large vessel stroke (LVS), while tortuous vascular anatomy still remains one major challenge in mechanical thrombectomy. Prompt assessing and understanding cavernous internal carotid artery (cICA) tortuosity may help to predict procedural complexities of mechanical thrombectomy and thus improve the clinical outcomes.

METHODS

A retrospective review was performed on a cohort of LVS patients with thromboaspiration catheter. Simplified classification of cICA tortuosity was applied by measurement of the angle of the posterior genus (P) and the height from the peak of the posterior genu to the trough of the anterior genu (D). Statistical analyses were performed to analyze differences among the obtained types of cICA tortuosity regarding procedural characteristics and clinical outcomes.

RESULTS

A total of 150 patients with LVS proximal to the internal ICA terminus and middle cerebral artery (MCA) were included in this study, and three types of cICA tortuosity were defined by the simplified classification. The index, such as patients ages and hypertension, procedural fluoroscopy time, the degree of cICA tortuosity, first-pass success, final reperfusion, and 90-day mortality showed significant differences among the three types (P < 0.05), while 90-day good outcome (mRS 0-2) only presented significant difference between Type I and Type III (P < 0.05).

CONCLUSIONS

The study indicated that the grading of cICA tortuosity is highly correlated with procedural complexity and clinical outcome in mechanical thrombectomy. The proposed classification system may be helpful in pre-procedure prognostication complexity and clinical outcomes.Abbreviations:LVS: large vessel stroke; cICA: cavernous internal carotid artery; mRS: modified Rankin Scale; AIS: acute ischemic stroke; MCA: middle cerebral artery; M1: first division of middle cerebral artery; M2: second division of middle cerebral artery; M3: third division of middle cerebral artery; TICI: Thrombolysis In Cerebral Infarction; TICI 2b: two-thirds of occluded territory reperfusion; DSA: digital subtraction angiography; FT: fluoroscopy time.

Practical use and underlying physics of the BENCHMARK™ BMX™ 96 for large-bore aspiration thrombectomy: Case report of initial institutional experience

Endovascular thrombectomy (EVT) is part of first-line intervention for acute ischemic stroke management. Recent technological advances have demonstrated that large-bore catheters are an attractive approach for EVT. A multitude of approaches such as A Direct Aspiration first Pass Technique (ADAPT) or in conjunction with stent retrieval (Solumbra technique) have been developed with increasingly large-bore catheters, demonstrating safety and efficacy. Furthermore, these techniques have demonstrated promise for the intervention of cerebral venous thrombosis as well as posterior circulation ischemic events. Recently, advances in neurointerventional catheters have focused on improved maneuverability to navigate the neurovasculature, as well as larger inner diameters for improved procedural versatility, including aspiration. We describe a case report highlighting our early institutional experience with the recently developed large-bore catheter, the BENCHMARK™ BMX™ 96. The case report entails near complete occlusion of the internal carotid artery from acute thrombus and the utility of the BMX™ 96 catheter for treatment of such extensive clot burden. The applicability of large-bore aspiration catheters, with an emphasis on recent advances, for mechanical thrombectomy in arterial as well as venous systems is discussed. To our knowledge, this is the first reported case of use of the BENCHMARK™ BMX™ 96 access system for EVT in acute ischemic stroke. Such new-generation large-bore catheters are a promising advance in neurointervention, and our early institution experience highlights the ease of use and versatility for neurointerventional procedures such as EVT.

Familiarization with Contact Aspiration using Non-Penetrating of the Thrombus (CANP) Technique as the Initial Procedure for Acute Ischemic Stroke

OBJECTIVES

This study aimed to prove the safety and efficacy of the contact aspiration using non-penetrating of thrombus (CANP) technique for the initial procedure for acute ischemic stroke and to increase operator familiarization with the technical aspects of the CANP technique.

MATERIALS AND METHODS

A total of 103 patients with large-vessel stroke who were treated using thrombectomy alone at our institution between April 2019 and March 2021 were included in this study. CANP technique was performed using a large lumen catheter (inner diameter, ≥0.060 in.) without penetrating a thrombus. Results of the CANP technique, including the procedure time; first-pass effect (FPE); angiographical recanalization; functional independence; thrombus migration; and intracerebral hemorrhage (ICH) were compared with combined technique.

RESULTS

A total of 77 patients (74.8%) were scheduled to undergo the CANP technique for initial procedure, and 50 (64.9%) attempted the CANP technique. Of 50 patients with CANP technique, 33 (66.0%) achieved angiographically good recanalization using CANP technique alone. FPE was achieved in 31 patients (62.0%) in CANP technique group; the rate of FPE was significantly higher (p = 0.008). Asymptomatic ICH were significantly smaller in the CANP technique group (p = 0.008). The median interval of only the CANP technique was 20 (IQR, 16-29.5) min for groin puncture to final recanalization, and was significantly faster (p < 0.001).

CONCLUSIONS

CANP technique was safe with low risk of hemorrhagic complication and effective for the initial procedure of acute ischemic stroke.