Mechanical Thrombectomy Using the New ERIC Retrieval Device Is Feasible, Efficient, and Safe in Acute Ischemic Stroke: A Swiss Stroke Center Experience

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.

Endovascular treatment of acute ischemic stroke with a fully radiopaque retriever: A randomized controlled trial

Objective

The Neurohawk retriever is a new fully radiopaque retriever. A randomized controlled non-inferiority trial was conducted to compare the Neurohawk and the Solitaire FR in terms of safety and efficacy. In order to evaluate the efficacy and safety of endovascular treatment in acute ischemic stroke (AIS) caused by intracranial atherosclerotic disease (ICAD) larger vessel occlusion (LVO), a sub-analysis was performed.

Methods

Acute ischemic stroke patients aged 18-80 years with LVO in the anterior circulation were randomly assigned to undergo thrombectomy with either the Neurohawk or the Solitaire FR. The primary efficacy endpoint was successful reperfusion (mTICI 2b-3) rate by the allocated retriever. A relevant non-inferiority margin was 12.5%. Safety outcomes were symptomatic intracranial hemorrhage (sICH) and all-cause mortality within 90 days. Secondary endpoints included first-pass effect (FPE), modified FPE, and favorable outcomes at 90 days. In subgroup analysis, the patients were divided into the ICAD group and non-ICAD group according to etiology, and baseline characteristics, angiographic, and clinical outcomes were compared.

Results

A total of 232 patients were involved in this analysis (115 patients in the Neurohawk group and 117 in the Solitaire group). The rates of successful reperfusion with the allocated retriever were 88.70% in the Neurohawk group and 90.60% in the Solitaire group (95%CI of the difference, -9.74% to 5.94%; p = 0.867). There were similar results in FPE and mFPE in both groups. The rate of sICH seemed higher in the Solitaire group (13.16% vs. 7.02%, p = 0.124). All-cause mortality and favorable outcome rates were comparable as well. In subgroup analysis, 58 patients were assigned to the ICAD group and the remaining 174 to the non-ICAD group. The final successful reperfusion and favorable outcome rates showed no statistically significant differences in two groups. Mortality within 90 days was relatively lower in the ICAD group (6.90% vs. 17.24%; p = 0.054).

Conclusion

The Neurohawk retriever is non-inferior to the Solitaire FR in the mechanical thrombectomy of large vessel occlusion-acute ischemic stroke (LVO-AIS). The sub-analysis suggested that endovascular treatment including thrombectomy with the retriever and essential rescue angioplasty is effective and safe in AIS patients with intracranial atherosclerotic disease-larger vessel occlusion (ICAD-LVO).

Clinical trial registration

https://clinicaltrials.gov/ct2/show/NCT04995757, number: NCT04995757.

Favorable first-pass recanalization rates with NeVa™ thrombectomy device in acute stroke patients: Initial clinical experience

BACKGROUND

The NeVa™ thrombectomy device (Vesalio LLC, Nashville, USA) has been reported to succeed in large vessel occlusion thrombectomy in animal, in-vitro, and clinical studies. Designed with Drop Zone technology, a closed distal tip, and strong expansive radial force, the device demonstrated particular efficiency in resistant "white" thrombi in preclinical research. Our goal is to determine the safety and performance of this novel stent retriever on first-pass rates and overall recanalization.

METHODS

The Interventional Neurology Database is a prospectively maintained database of anterior and posterior circulation stroke thrombectomy cases. We retrospectively analyzed cases where the NeVa™ thrombectomy device was used as the first-line treatment strategy. Data collection occurred between January 2019 and January 2020. First-pass recanalization, final recanalization, 90-day functional outcome, complication, and bleeding rates are reported.

RESULTS

One hundred eighteen patients were treated with the NeVa™ thrombectomy device. The mean patient age was 69 ± 14 years, the median baseline National Institutes of Health Stroke Scale was 14, and the median initial Alberta Stroke Program Early Computed Tomography score was 8. The median time from groin puncture to successful recanalization was 29 min (interquartile range (IQR): 20-40). First-pass recanalization rates were 56.8% (modified treatment in cerebral infarction (mTICI) 2b/3) and 44.9% (mTICI 2c/3). Final successful recanalization rate was 95.8% (thrombolysis in cerebral infarction 2b/3). Favorable functional outcome (modified Rankin Scale 0-2) was 53% in the "first-pass" subgroup and 42.4% in the total patient population. The median number of passes to achieve the final recanalization score was 1 (IQR 1-2). The rate of embolization into new territory was 1.7%. Four patients (3.3%) had symptomatic hemorrhage.

CONCLUSIONS

In our experience, the NeVa™ device demonstrated high first-pass and overall recanalization rates along with a good safety profile.

Mechanical thrombectomy using the new Tigertriever in acute ischemic stroke patients - A Swiss prospective multicenter study

PURPOSE

Tigertriever is a novel operator-adjustable clot retriever designed to enhance the operator's options to control the interaction of retriever and clot. The aim of this study was to assess the feasibility, safety and efficacy of the Tigertriever device system.

METHODS

Prospective multi-center registry study at three comprehensive stroke centers in Switzerland from 2017 to 2019 of patients with acute ischemic stroke (AIS) and large vessel occlusion (LVO) using Tigertriever as a first-line device.

RESULTS

30 AIS patients (median age 72.5 years (IQR 64-79), 50% women) with a median NIHSS on admission of 11 (IQR 6-13) and a median ASPECT score of 9 (IQR 7-10) were treated with the new Tigertriever and included in this study. The first-pass effect was 24% (n = 7). A good recanalization (eTICI 2 b/2c/3) was achieved in 94% of the cases. Median mRS at 90 days was 1 (IQR 1-2).

CONCLUSION

This study demonstrated feasibility, safety and effectiveness of the Tigertriever in AIS patients with LVO with a high reperfusion rate.

Wake-up stroke: imaging-based diagnosis and recanalization therapy

Wake-up stroke (WUS) is a subgroup of ischemic stroke in which patients show no abnormality before sleep while wake up with neurological deficits. In addition to the uncertain onset, WUS patients have difficulty to receive prompt and effective thrombolytic or reperfusion therapy, leading to relatively poor prognosis. A number of researches have indicated that CT or MRI based thrombolysis and endovascular therapy might have benefits for WUS patients. This review article narratively discusses the pathogenesis, risk factors, imaging-based diagnosis and recanalization treatments of WUS with the purpose of expanding current treatment options for this group of stroke patients and exploring better therapeutic methods. The result showed that multimodal MRI or CT scan might be the best methods for extending the time window of WUS and, therefore, a large proportion of WUS patients could have favorable prognosis.

Evaluation of stroke thrombectomy including patients where IV thrombolysis is contraindicated or has failed: a randomized trial of two novel thrombectomy devices

BACKGROUND

Study was a PROBE design phase II randomized controlled trial (RCT). We assessed trial feasibility and technical efficacy and safety of two novel thrombectomy devices - ERIC (a retriever device) and SOFIA (a distal access catheter) - used alone or in combination depending on operator preference.

METHODS

Four UK neuroscience centers enrolled adults with proximal large artery occlusion (LAO) stroke on imaging where arterial puncture was achievable within 5.5 hours (8.5 hours for posterior circulation) of symptom onset; National Institutes of Health Stroke Scale (NIHSS) ≥6 with limited ischemic change on CT imaging. Randomization was 2:1 into intervention arm (ERIC and/or SOFIA). Patients and core lab were blinded to allocation. Primary outcome was independent core lab adjudication of reperfusion (modified Thrombolysis in Cerebral Infarction (mTICI) scale). Secondary outcomes were modified Rankin score (mRS) at 90 and 365 days (independence and shift analysis), 30-day mortality, symptomatic intracranial hemorrhage (sICH), procedural complications and NIHSS change.

RESULTS

Sixty-six patients were enrolled. TICI 2B/3 reperfusion was achieved in 72% in intervention compared with 90% in control arm on intention to treat (ITT) analysis (P=0.2) and 78% compared with 86% on per protocol analysis (P=0.7). Functional independence at 90 days was 40% (intervention) compared with 43% (control) on ITT analysis (P=1.0). sICH rates were low at 0% and 5%, respectively (P=0.3). The 30-day mortality was 9% intervention compared with 14% control (P=0.7).

CONCLUSIONS

Study indicated feasibility of a phase II RCT trial approach for assessing new thrombectomy devices. In a broad LAO stroke population ERIC and SOFIA were not statistically different from control devices. Larger trials are needed.

Embolus Retriever with Interlinked Cages (ERIC) versus conventional stent retrievers for thrombectomy: a propensity score-based analysis

BACKGROUND

The Embolus Retriever with Interlinked Cages (ERIC) is one of the latest devices for thrombectomies. It has several architectural features that are supposed to enhance its ability to remove clots and prevent distal emboli. We aimed to compare ERIC with standard stent retrievers (SRs) using propensity score (PS) matching.

METHODS

The clinical and radiological data of all consecutive patients treated with ERIC or standard FDA-approved stent retrievers were collected from a prospective multicenter registry. We compared procedural outcomes (recanalization rates according to the modified Thrombolysis In Cerebral Infarction (mTICI) score and procedural complications) and clinical outcomes (modified Rankin Scale (mRS) and mortality at 3 months). Matching of the populations with PS was performed to account for differences in baseline characteristics.

RESULTS

A total of 1230 patients were included. In both the PS-matched cohort (195 ERIC patients, 630 SR patients) and the inverse probability of treatment weighting PS-adjusted cohort (206 ERIC patients, 1024 SR patients) there was no difference in terms of successful recanalization (modified TICI score ≥2b), good clinical outcome (mRS=0-2 or equal to pre-stroke mRS), or mortality at 3 months. Patients treated with first-line ERIC had a higher rate of complete recanalization (mTICI 3); however, they also required more passes and more frequent rescue therapy than the SR patient group.

CONCLUSION

In a large multicenter registry with PS matching, the ERIC device provided equivalent angiographic and clinical results to conventional SRs.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov Unique identifier: NCT03776877.

Mechanical thrombectomy with a novel stent retriever with multifunctional zones: Initial clinical experience with the NeVa™ thrombectomy device

BACKGROUND AND PURPOSE

The NeVa™ (Vesalio, Nashville, Tennessee) thrombectomy device is a CE-approved novel hybrid-cell stent retriever with offset enlarged openings coupled with functional zones and a closed distal end. The device was designed to incorporate and trap resistant emboli. The purpose was to determine the safety and efficacy of the NeVa™ stent.

METHODS

Prospective data was collected on the first thirty consecutive patients treated at four stroke centers with NeVa™ as first line treatment between December 2017 and May 2018. Clinical outcome measures included re-perfusion scores after each pass, complications (per-procedural complications, device related adverse events, all intracerebral hemorrhage (ICH) and symptomatic ICH (sICH) on follow up imaging), 24 hour NIHSS, mRS at discharge and 90 days. Baseline data as well as treatment parameters were documented.

RESULTS

Mean presenting NIHSS was 16. Sites of primary occlusion were 10 ICA, 16 M1-MCA, 3 M2-MCA and one basilar. There were five tandem occlusions. Reperfusion outcomes after each NeVa pass; TICI ≥ 2b after first pass 63%, after 1 or 2 passes 83%, after 1 to 3 passes 90%. TICI 2c-3 after first pass 47%, after 1-2 passes 57%, after 1-3 passes 60%. TICI ≥ 2b after final pass 93%; TICI 2c-3, 63%. There were no device related serious averse events and no sICH. Clot material was partially or completely incorporated into the device after 70% passes. The mean 24 hour NIHSS was 7 and the 90 day mRS was 0-2 in 53%.

CONCLUSIONS

The NeVa™ device demonstrated a high rate of first pass complete reperfusion effect, a good safety profile and favorable 90 day clinical outcomes in this initial clinical experience.

Endovascular Metal Devices for the Treatment of Cerebrovascular Diseases

Cerebrovascular disease involves various medical disorders that obstruct brain blood vessels or deteriorate cerebral circulation, resulting in ischemic or hemorrhagic stroke. Nowadays, platinum coils with or without biological modification have become routine embolization devices to reduce the risk of cerebral aneurysm bleeding. Additionally, many intracranial stents, flow diverters, and stent retrievers have been invented with uniquely designed structures. To accelerate the translation of these devices into clinical usage, an in-depth understanding of the mechanical and material performance of these metal-based devices is critical. However, considering the more distal location and tortuous anatomic characteristics of cerebral arteries, present devices still risk failing to arrive at target lesions. Consequently, more flexible endovascular devices and novel designs are under urgent demand to overcome the deficiencies of existing devices. Herein, the pros and cons of the current structural designs are discussed when these devices are applied to the treatment of diseases ranging broadly from hemorrhages to ischemic strokes, in order to encourage further development of such kind of devices and investigation of their use in the clinic. Moreover, novel biodegradable materials and drug elution techniques, and the design, safety, and efficacy of personalized devices for further clinical applications in cerebral vasculature are discussed.

The Wall Apposition Evaluation for a Mechanical Embolus Retrieval Device

A computational evaluation approach to the wall apposition of a cerebral mechanical emboli retrieval device (MERD) is presented. The typical enclosed multilattice structure, manufactured from the thin-walled Nitinol tube, consists of repeated “V”-shaped unit cells. During interventional thrombectomy, the MERD system is delivered inside an artery stenosis segment to capture emboli and restore cerebral blood flow. The wall apposition, which deteriorates during embolus capture, occurs during system migration along the tortuous intracranial vessel. The commercial finite element analysis (FEA) solver ABAQUS 6.10 Standard and user subroutine (UMAT/Nitinol) are utilized to study the ability to remain in close contact with the curved vessel wall during migration. In this numerical analysis, the influence of the contacting interference loadings on structure deformation and strain field distribution is obtained and analyzed. The results indicate that the middle segment of the MERD seriously contracts or collapses inside the curved vessel. In addition, the peak strain is in the apex flow-prone region and maintains at the safe range.

Successful recanalization using the Embolus Retriever with Interlinked Cage for acute stroke due to calcified cerebral emboli

Mechanical thrombectomy is a safe and effective treatment in patients with acute ischemic stroke caused by large vessel occlusions. However, in rare cases, the procedure may be challenging due to the composition of the embolus. We describe a case of a mechanical thrombectomy with the Embolus Retriever with Interlinked Cage (ERIC) device in a patient with an acute ischemic stroke due to calcified cerebral emboli in the middle cerebral artery. The procedure was done after a failed recanalization attempt with manual aspiration thrombectomy. An 82-year-old woman presented to the emergency department with a sudden onset of right-sided weakness. A computed tomographic angiography showed left middle cerebral (M1 branch) calcified emboli. After the administration of an intravenous thrombolytic agent, the patient was transferred to the angiographic suite for a mechanical thrombectomy. After failure to recanalize the vessel with manual aspiration thrombectomy, successful recanalization was achieved via mechanical thrombectomy using the ERIC device. Mechanical thrombectomy with an ERIC device can be a useful option in cases of acute ischemic stroke caused by calcified cerebral emboli.

Mechanical Thrombectomy: Emerging Technologies and Techniques

BACKGROUND

The treatment of acute ischemic stroke due to large vessel occlusion (LVO) has revolutionized in the last decade. We sought to compile the most relevant literature published about the evolution in treating this disabling and fatal disease.

METHODS

A literature review of recent studies describing early treatment options like intravenous tissue plasminogen activator to the latest mechanical thrombectomy (MT) techniques was performed. We described in a chronological order the evolution of LVO treatment.

RESULTS

Recanalization rates with newer techniques and MT devices approach a 90% of effectiveness. Timely interventions have also resulted in better clinical outcomes with approximately 50% of patient achieving functional independence at 90 days. At least 14 new third generation thrombectomy devices are currently being evaluated in in vitro and clinical studies.

CONCLUSIONS

The treatment of LVO with MT is feasible and safe. MT is standard of care in treating acute ischemic stroke due to LVO.

Embolus Retriever with Interlinked Cages versus other stent retrievers in acute ischemic stroke: an observational comparative study

Background and purpose

Given the promising performance of the new Embolus Retriever with Interlinked Cages (ERIC) in smaller case series, we sought to assess the efficacy and safety of mechanical thrombectomy (MT) with ERIC compared with other stent retrievers (SRs) in acute ischemic stroke due to large vessel occlusion (LVO).

Methods

We reviewed the databases of two comprehensive stroke centers in in Germany and Switzerland for MT due to LVO in the anterior circulation with either ERIC or another SR as a first device. Co-primary outcome was defined as successful recanalization (Thrombolysis in Cerebral Infarction 2b/3) after the first device and favorable outcome (modified Rankin Scale score 0–2) at 90 days' follow-up. Multiple logistic regression analysis was applied to adjust for potential confounders.

Results

183 consecutive patients with stroke were treated with either ERIC (49%) or a SR (51%) as the first device and successful recanalization was seen in 82% and 57%, respectively (P<0.001). Adding SR to futile ERIC recanalization or vice versa increased final recanalization rates (ERIC: 87%, SR: 79%). The use of ERIC as a first device resulted in favorable clinical outcome in 50% compared with 35% when a SR was used (P=0.038), an effect driven by age, stroke severity, presence of carotid-T-occlusion, and general anesthesia and not by the device deployed.

Conclusion

The use of ERIC as a first device appeared to be associated with higher rates of successful recanalization and resulted in better functional outcome. However, favorable outcome was not attributable to ERIC. Most importantly, both device types complemented one another and improved final recanalization rates when used successively.

Thrombectomy using the EmboTrap device: core laboratory-assessed results in 201 consecutive patients in a real-world setting

Background

We studied patients treated with the EmboTrap revascularization device in a prospective registry which is core laboratory evaluated by physicians from external centers. The goal was to determine how the EmboTrap would perform under the everyday conditions of a high-volume stroke center.

Methods

We examined all patients with acute stroke treated with the Embotrap device from October 2013 to March 2017 in our center. Imaging parameters and times were adjudicated by core laboratory personnel blinded to clinical information, treating physician, and clinical outcomes. Clinical evaluation was performed by independent neurologists and entered in a national registry. Evaluated endpoints were: successful revascularization (modified Thrombolysis in Cerebral Infarction (mTICI) 2b–3) and good clinical outcomes at 3 months (modified Rankin Scale (mRS) 0–2).

Results

201 consecutive patients with a median NIH Stroke Scale (NIHSS) score of 15 (range 2–30) were included. 170 patients (84.6%) achieved mTICI 2b–3 reperfusion. The median number of attempts was 2 (range 1–10) with 52.8% of the population achieving good functional outcomes (mRS 0–2) at 3 months. On univariate analysis, good functional outcome was associated with the number of attempts, puncture-to-reperfusion time, anterior circulation occlusion, and NIHSS score. On multivariate analysis, pre-treatment NIHSS (OR 0.845 per point, 95% CI 0.793 to 0.908, P<0.001) and puncture-to-reperfusion time (OR 0.9952 per min, 95% CI 0.9914 to 0.9975, P=0.023) were associated with good functional outcomes at 3 months.

Conclusion

The Embotrap device has a high rate of successful reperfusion. Our core laboratory-audited single-center experience suggests the technical feasibility and safety of the Embotrap for first-line use in a real-world setting.

Mechanical Thrombectomy with the Embolus Retriever with Interlinked Cages in Acute Ischemic Stroke: ERIC, the New Boy in the Class

BACKGROUND AND PURPOSE

The Embolus Retriever with Interlinked Cages (ERIC) device is a novel stent retriever for mechanical thrombectomy. It consists of interlinked cages and could improve procedural benchmarks and clinical outcome compared with classic stent retrievers. This study compares the rates of recanalization, favorable clinical outcome, procedural adverse events, and benchmarks between the ERIC device and classic stent retrievers.

MATERIALS AND METHODS

From 545 patients treated with thrombectomy between 2012 and 2015, 316 patients were included. The mean age was 69 ±13 years, the mean baseline NIHSS score was 17 ± 5, and 174 (55%) were men. The ERIC was used as the primary thrombectomy device in 59 (19%) patients. In a propensity score matched analysis including the NIHSS score, clot location, delay to groin puncture, neurointerventionalist, and anesthetic management, 57 matched pairs were identified.

RESULTS

Patients treated with the ERIC device compared with classic stent retrievers showed equal rates of recanalization (86% versus 81%, P = .61), equal favorable 3-month clinical outcome (mRS 0-2: 46% versus 40%, P = .71), and procedural adverse events (28% versus 30%, P = 1.00). However, in patients treated with the ERIC device, thrombectomy procedures were less time-consuming (67 versus 98 minutes, P = .009) and a rescue device was needed less often (18% versus 39%, P = .02) compared with classic stent retrievers.

CONCLUSIONS

Mechanical thrombectomy with the ERIC device is effective and safe. Rates of favorable procedural and clinical outcomes are at least as good as those with classic stent retrievers. Of note, the ERIC device might be time-saving and decrease the need for rescue devices. These promising results call for replication in larger prospective clinical trials.

Novel and emerging technologies for endovascular thrombectomy

Endovascular thrombectomy device improvements in recent years have served a pivotal role in improving the success and safety of the thrombectomy procedure. As the intervention gains widespread use, developers have focused on maximizing the reperfusion rates and reducing procedural complications associated with these devices. This has led to a boom in device development. This review will cover novel and emerging technologies developed for endovascular thrombectomy.

Mechanical thrombectomy with the ERIC retrieval device: initial experience

Objective

To report our experience with the Embolus Retriever with Interlinked Cage (ERIC) stentriever for use in mechanical endovascular thrombectomy (MET).

Methods

Thirty-four consecutive patients with acute stroke (21 men and 13 women; median age 66 years) determined appropriate for MET were treated with ERIC and prospectively included over a 6-month period at three different centers. The ERIC device differs from typical stentrievers in that it is designed with a series of interlinked adjustable nitinol cages that allow for fast thrombus capture, integration, and withdrawal. The evaluated endpoints were successful revascularization (Thrombolysis in Cerebral Infarction (TICI) 2b–3) and good clinical outcomes at 3 months (modified Rankin Scale (mRS) 0–2).

Results

Locations of the occlusions included the middle cerebral artery (13 patients), terminal carotid artery (11 patients), basilar artery (1 patient), and tandem occlusions (9 patients). IV thrombolysis was performed in 20/34 (58.8%) patients. Median times from symptom onset to recanalization and from puncture to recanalization were 325.5 min (180–557) and 78.5 min (14–183), respectively. Used as the first-line device, ERIC achieved a successful recanalization in 20/24 (83.3%) patients. Successful recanalization was associated with lower National Institutes of Health Stroke Scale scores at 24 h (8±6.5 vs 21.5±2.1; p=0.008) and lower mRS at 3 months (2.7±2.1 vs 5.3±1.1; p=0.04). Three procedural complications and four asymptomatic hemorrhages were recorded. Good clinical outcomes at 3 months were seen in 15/31 (48.4%) patients.

Conclusions

The ERIC device is an innovative stentriever allowing fast, effective, and safe MET.