Super large-bore ingestion of clot (SLIC) leads to high first pass effect in thrombectomy for large vessel occlusion

Endovascular treatment of cerebral venous sinus thrombosis: A systematic review and meta-analysis of efficacy based on technique

BackgroundCerebral venous sinus thrombosis (CVST) is rare but potentially life-threatening. Although systemic anticoagulation is the primary treatment, endovascular thrombectomy (EVT) or thrombolysis may be considered for refractory cases. Considering advanced techniques and device technology, we undertook an updated systematic review and meta-analysis to evaluate clinical and radiographic outcomes for treating CVST.MethodsWe searched PubMed and EMBASE for studies describing CVST patients treated with EVT. Presenting symptoms, procedural details, and clinical and radiographic outcomes were analyzed. Random-effects models were generated to calculate pooled proportions of clinical and radiographic outcome variables.ResultsWe analyzed 26 studies comprising 273 patients (mean age 37 years, 57.7% female). Preprocedural intracranial hemorrhage was present in 167/243 (67.1%) patients. Endovascular thrombectomy techniques included aspiration thrombectomy alone (29.3%), aspiration plus stent retriever (19%), stent retriever alone (12.5%), balloon/catheter maceration (6.6%), and AngioJet rheolytic system (32.6%). Random-effects model indicated that 37% of patients had complete recanalization and 57% had partial recanalization. The model indicated that 79% of patients had a good clinical outcome (modified Rankin Scale score 0-2) at last follow-up. There were no statistically significant differences between modern systems (stent retriever and/or aspiration) and older systems (rheolytic thrombectomy and catheter maceration). Aspiration alone yielded a significantly higher frequency of good clinical outcomes compared with the combined technique (83.8% vs. 61.5%, p = 0.004).ConclusionEndovascular thrombectomy for CVST refractory to systemic anticoagulation achieved high recanalization rates, favorable outcomes, and low procedural complication rates. Modern and older techniques exhibited similar safety and efficacy. These findings support EVT as an effective treatment option.

First in-human use of super large-bore novel 0.092-inch catheter positioned in M1 segment of middle cerebral artery for aspiration thrombectomy

An octogenarian patient with a medical history of hypertension and prior stroke (baseline modified Rankin Scale score of 1) presented with acute onset left-sided hemiplegia and neglect and was found to have a right middle cerebral artery M1 occlusion, likely from an embolic clot as there was no hint of intracranial atherosclerosis or dissection in the CT scan. He underwent emergent EVT using direct aspiration technique via a novel super large-bore 0.092-inch ID catheter, which was positioned in the M1 segment. This is the first clinical report of using a 0.092-inch ID catheter in the M1 segment, which resulted in full recanalisation (thrombolysis in cerebral infarction score 3 (TICI3)) of the artery without any adverse events. The patient had significant early clinical improvement, and a follow-up imaging revealed a relatively small infarct size and no haemorrhagic complications. Utilisation of super large-bore 0.092-inch ID catheter for direct aspiration in proximal large vessel occlusion might further optimise the efficacy of the aspiration pass by increasing the aspiration force and inducing local flow arrest.

Tenzing Assisted Delivery of Aspiration (TADA) technique for thrombectomy of medium vessel occlusions using the Freeclimb 54 catheter: multicenter experience

BACKGROUND

Medium vessel occlusions (MeVOs) account for 25-40% of acute ischemic stroke. The Tenzing 5 (Route 92 Medical, San Mateo, California, USA) and FreeClimb 54 (Route 92 Medical, San Mateo, California, USA) catheter is a novel delivery-aspiration catheter combination designed to facilitate aspiration thrombectomy (AT) of MeVOs. We report our clinical experience using the Tenzing assisted delivery of aspiration (TADA) technique with FreeClimb 54 for first-line AT of MeVO.

METHODS

We retrospectively reviewed consecutive patients who underwent MeVO first-line AT using TADA with FreeClimb 54 at nine institutions in the USA and one in New Zealand.

RESULTS

94 MeVOs (65 primary, 29 secondary) were treated in 92 patients: median age 71 (IQR 58-81) years; 49/92 (53%) women. FreeClimb 54 was successfully delivered by Tenzing 5 to all 94/94 MeVOs: 26 proximal M2; 44 distal M2; 5 M3; 6 A2; 4 A3; and 8 P2. Median target vessel diameter on DSA was 1.7 (IQR 1.4-1.8) mm. A leading microwire was used to advance Tenzing in 84% of cases. A stent retriever was used for additional thrombectomy passes in 6/94 (6%) patients. For a primary MeVO, final modified expanded Thrombolysis in Cerebral Infarction (meTICI) 2B-3 reperfusion was achieved in 63/65 (97%) patients, after a median of 1 (IQR 1-2) pass, with a first pass effect (FPE, meTICI 2C-3) in 43/65 (66%). Secondary MeVO FPE (eTICI 2C-3) was achieved in 20/29 (69%) patients. Tenzing 5-FreeClimb 54 related complications occurred in 2/94 (2%) patients: one perforation with asymptomatic subarachnoid hemorrhage and one embolus to new territory.

CONCLUSIONS

MeVO first-line AT using the TADA technique with Tenzing 5 and FreeClimb 54 had a high FPE with a low complication rate.

Early experience with the Aristotle Colossus 0.035' macrowire for mechanical thrombectomy in 30 consecutive cases

INTRODUCTION

Recent literature continues to demonstrate the successful role of large-bore aspiration catheters in thrombus ingestion during mechanical thrombectomy. However catheter-to-microwire step-off and distal navigation are ongoing challenges in thrombectomy. A new to market 0.035' macrowire (Aristotle 35 Colossus Guidewire, Scientia Vascular, West Vale City, UT) may address such challenges. We report here our early experience in 30 mechanical thrombectomy cases.

MATERIALS AND METHODS

We analyzed a prospectively maintained database of the senior authors to identify cases utilizing a 0.035' macrowire with 0.035' aspiration catheters for mechanical thrombectomy.

RESULTS

Thirty consecutive cases were identified. Seventeen (57%) patients were female with an average age of 75.3 ± 2.2 years (range 55-97). Average presenting NIHSS was 13.0 ± 1.7. Thrombus locations included 7% (n = 2) in the cervical ICA, 47% (n = 14) in the M1, 43% (n = 13) in the M2, and 3% (n = 1) in the P1. An 088' ID aspiration catheter was navigated to at least the M1 segment in all anterior circulation cases and the basilar in the posterior circulation case. The 0.035' macrowire was placed proximal to the occlusion in all cases allowing coaxial 035' and 071' catheter aspiration passes. TICI 2C/3 was achieved in 87% of cases (n = 26) and TICI 2B in the remaining cases. There were no wire-related perforations or vessel dissections.

CONCLUSION

The Colossus 0.035' macrowire may offer advantages over its smaller counterparts by reducing ledge effect and the need to cross the thrombus. Further comparative studies against currently available microwires in various anatomies are warranted.

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.

A prospective, randomized, controlled, interventional clinical trial to evaluate the safety and efficacy of the medical monopoint reperfusion system for aspiration thrombectomy in acute ischemic stroke patients (SUMMIT MAX): Trial rationale and design

BACKGROUND

Treatment of large vessel occlusion (LVO) using mechanical thrombectomy with or without intravenous thrombolysis has demonstrated better outcomes compared to medical treatment alone. Large-bore aspiration catheters have been recently introduced. Their effectiveness and safety have not been demonstrated in a randomized trial. The SUMMIT MAX study is designed to address this question.

METHODS

SUMMIT MAX is a randomized controlled trial where the effectiveness and safety of the large-bore Monopoint Reperfusion system (Route 92 Medical, San Mateo, CA), will be compared to the currently largest available FDA-cleared aspiration thrombectomy device the AXS Vecta Aspiration system (Stryker Neurovascular, Fremont, CA). The study is a multi-center, prospective, randomized, controlled, interventional, open label clinical trial. The hypothesis is that the effectiveness measured by the recanalization rate (modified thrombolysis in cerebrovascular infarction - mTICI) and safety measured by symptomatic intracranial hemorrhage rate (sICH) of the medical monopoint reperfusion system is non-inferior to the AXS Vecta Aspiration system.

RESULTS

Up to 250 subjects are enrolled with at least 50% of subjects enrolled by US sites. The primary effectiveness endpoint is successful arterial revascularization defined as an mTICI score ≥ 2b after use of the assigned device adjudicated by an independent core lab. The primary safety endpoint is defined as sICH within 24 h (-8/+24) post-procedure. Secondary endpoints include successful arterial revascularization defined as a mTICI score ≥ 2b after use of the assigned device with or without adjunctive therapy; device-related serious adverse events; all asymptomatic hemorrhages; time from groin puncture to final angiogram; and rate of first pass effect defined as mTICI 2b after first pass with the assigned device stratified by age (≤85, ≥ 86).

CONCLUSION

SUMMIT MAX is a randomized controlled trial comparing the effectiveness and safety of a new large bore class of aspiration devices to the currently largest FDA-cleared aspiration device available.

Comparison of aspiration catheter performance using adaptive pulsatile aspiration in an in vitro thrombectomy model

OBJECTIVE

Aspiration with a pump or syringe is a mainstay of mechanical thrombectomy (MT) for acute ischemic stroke (AIS), but this technology has seen minimal evolution. Non-continuous adaptive pulsatile aspiration (APA) has been proposed as a potential alternative to standard continuous aspiration as a means of improving revascularization efficiency.

METHODS

Using a pathophysiological flow bench model with a synthetic clot, we performed in vitro thrombectomies using the ALGO® Von Vascular, Inc. (Sunrise, FL) APA pump. A total of 25 FDA-approved aspiration catheters were tested, representing inner diameters (ID) from 0.035 in. to 0.088 in. The pump was used in 30 trials with each catheter to remove a simulated M1 occlusion. Revascularization, clot ingestion, time to clot removal, and distal embolization were measured.

RESULTS

Among catheters tested using APA, first-pass TICI 3 revascularization was achieved in 100% of the 750 thrombectomy trials using 25 different catheters. There were no distal emboli detected in any trial run. Complete clot ingestion into the pump collection chamber was achieved in 87% to 100% of trials (overall 95%) with clot in the remaining trials corking within the catheter and removed from the model. Time from clot contact to clot removal ranged from 11 s to 90 s (mean 22.6 s, SD 16.8 s), which was negatively correlated with catheter ID (p = 0.007).

CONCLUSION

APA via the Von Vascular, Inc. ALGO® pump achieved a high success rate in an in vitro MT model. All catheters tested with the pump achieved complete reperfusion in all trials, and complete clot ingestion into the pump was seen in a majority of trials. The promising in vitro performance of APA using multiple catheters warrants future in vivo investigation.

Acute management of cerebral venous thrombosis: Indications, technique, and outcome of endovascular treatment in two high-volume centers

INTRODUCTION

After several uncontrolled studies and one randomized clinical trial, there is still uncertainty regarding the role of endovascular treatment (EVT) in cerebral venous thrombosis (CVT). This study aims to describe and assess different acute management strategies in the treatment of CVT.

METHODS

We performed a retrospective analysis of an international two-center registry of CVT patients admitted since 2019. Good outcome was defined as a return to baseline modified Rankin scale at three months. We described and compared EVT versus no-EVT patients.

RESULTS

We included 61 patients. Only one did not receive systemic anticoagulation. EVT was performed in 13/61 (20%) of the cases, with a median time from diagnosis to puncture of 4.5 h (1.25-28.5). EVT patients had a higher median baseline NIHSS [6 (IQR 2-17) vs 0 (0-2.7), p = 0.002)] and a higher incidence of intracerebral hemorrhage (53.8% vs 20.3%, p = 0.03). Recanalization was achieved in 10/13 (77%) patients. Thrombectomy was performed in every case with angioplasty in 7 out of 12 patients and stenting in 3 cases. No postprocedural complication was reported. An improvement of the median NIHSS from baseline to discharge [6 (2-17) vs 1(0-3.75); p < 0.001] was observed in EVT group. A total of 31/60 patients (50.8%) had good outcomes. Adjusting to NIHSS and ICH, EVT had a non-significant increase in the odds of a good outcome [aOR 1.42 (95%CI 0.73-2.8, p = 0.307)].

CONCLUSIONS

EVT in combination with anticoagulation was safe in acute treatment of CVT as suggested by NIHSS improvement. Selected patients may benefit from this treatment.

Flow reversal during stroke thrombectomy

When performing mechanical thrombectomy for stroke patients, some physicians use balloon guide catheters (BGCs) in order to achieve flow reversal and thereby improve reperfusion quality. There is substantial evidence favoring the use of BGCs to improve reperfusion rates and clinical outcomes for thrombectomy patients; however, as we will outline in this review, there is also evidence that BGCs do not achieve reliable flow reversal in many circumstances. Therefore, if we are able to modify our techniques to improve the likelihood of flow reversal during thrombectomy maneuvers, we may be able to further improve reperfusion quality and clinical outcomes. This paper provides an overview of concepts on this topic and outlines some potential techniques to facilitate flow reversal more consistently, including a method to visually confirm it, with the aim of making iterative improvements towards optimal reperfusion for stroke patients.

Feasibility of super-bore 0.088″ mechanical thrombectomy in M1 vessels smaller than 8 French: Experience in 20 consecutive cases

INTRODUCTION

Superbore 0.088″ catheters provide a platform for optimizing aspiration efficiency and flow control during stroke mechanical thrombectomy procedures. New superbore catheters have the distal flexibility necessary to navigate complex neurovascular anatomy while providing the proximal support of traditional 8F catheters. The safety and feasibility of Zoom 88™ superbore angled-tip catheters in the middle cerebral artery (MCA) segments smaller than the catheter diameter have not been previously described.

METHODS

Twenty consecutive cases of acute MCA mechanical thrombectomy were retrospectively identified from the senior authors' prospectively maintained Institutional Review Board-approved database, in which the Zoom 88 (Imperative Care, Campbell, CA) catheter was successfully navigated to at least the M1 segment. Patient demographics, procedural details, and periprocedural information were analyzed. Rates and averages (standard errors) are generally reported.

RESULTS

The average National Institutes of Health Stroke Scale at presentation and age were 15 ± 2 and 73 ± 3 years, respectively. The M1 and M2 occlusions were evenly distributed. The average M1 measurements before thrombectomy ranged from 2.36 ± 0.07 mm proximally to 2.00 ± 0.11 mm distally, and after thrombectomy, they ranged from 2.34 ± 0.07 mm proximally to 1.97 ± 0.10 mm distally. First-pass modified thrombolysis in cerebral infarction (mTICI) 2C/3 recanalization was achieved in 40% of cases, and final mTICI 2C/3 recanalization was achieved in 90% of cases. A single case of mild vasospasm was managed with verapamil. No hemorrhagic or periprocedural complications were noted.

CONCLUSION

Superbore 0.088″ catheters with flexible distal segments can be safely navigated to the MCA to augment mechanical thrombectomy even when the MCA segment is smaller than the catheter.

Catheter design primer for neurointerventionalists

Neurovascular catheter technology has rapidly evolved over the past decade. While performance characteristics are well known to the practitioner, the design features of these new-generation catheters and their implications on performance metrics remain a mystery to most clinicians due to the limited number of available resources. This knowledge gap hampers informed device choices and also limits collaboration between clinicians and engineers. To aid fellow neurointerventionalists, in this primer we have summarized the basic concepts of catheter design and construction.