Safety and Efficacy of Mechanical Thrombectomy Using Stent Retrievers in the Endovascular Treatment of Acute Ischaemic Stroke: A Systematic Review

Mechanical thrombectomy for AIS from large vessel occlusion - current trends and future perspectives

Stroke is found to be one of the global top causes of mortality and the major factor in years of life with a handicap (DALYs). Ischemic strokes contributed to nearly 70% of all strokes worldwide. For endovascular thrombectomy in acute ischemic stroke with large vessel obstruction (AIS-LVO), using stent retrievers and/or reperfusion catheters has become the gold standard of therapy. The methodology involved keyword-based search in databases like PubMed, Embase, and Google Scholar for recent publications on mechanical thrombectomy (MT), AIS, large vessel occlusion (Large Vessel Occlusion (LVO)), screening relevant articles, retrieving full texts, and synthesizing key findings on procedural advancements, patient selection, COVID-19 (coronavirus disease 2019) impact, delay effects, effectiveness, clinical outcomes, and future perspectives. Only people with substantial cerebral artery obstruction may do well from MT. This includes the distal carotid artery and the proximal middle cerebral artery (segment M1). The size of a blocked vessel and NIHSS (National Institute of Health Stroke Scale) score are directly connected. Both the 2018 and 2019 versions of the AHA/ASA (American Heart Association/American Stroke Association) Guidelines for the Early Management of Patients with Acute Ischemic Stroke contained the recommendations that cases with AIS-LVO get endovascular therapy when administered during the time frame of 0-6 h after onset (Grade IA evidence). It is questionable whether this group of patients can be managed without the need for intravenous tissue plasminogen activator at the onset. When functional independence [modified Rankin Scale (mRS) score 2] was present at long-term follow-up, the endovascular intervention was favored. Tenecteplase, which differs from alteplase in terms of genetic variation, has a greater half-life and a higher level of fibrin selectivity, enabling bolus infusion. Studies have also demonstrated its efficacy and safety, as well as its long-term cost-effectiveness.

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.

The Efficacy and Safety of Ischemic Stroke Therapies: An Umbrella Review

Background: Ischemic stroke is a leading cause of morbidity and mortality in neurological diseases. Numerous studies have evaluated the efficacy and safety of ischemic stroke therapies, but clinical data were largely inconsistent. Therefore, it is necessary to summarize and analyze the published clinical research data in the field.

Objective: We aimed to perform an umbrella review to evaluate the efficacy and safety of ischemic stroke therapies.

Methods: We conducted a search for meta-analyses and systematic reviews on PubMed, the Cochrane Library, and the Web of Science to address this issue. We examined neurological function deficit and cognitive function scores, quality of life, and activities of daily living as efficacy endpoints and the incidence of adverse events as safety profiles.

Results: Forty-three eligible studies including 377 studies were included in the umbrella review. The results showed that thrombolytic therapy (tPA; alteplase, tenecteplase, and desmoteplase), mechanical thrombectomy (MTE), edaravone with tPA, stem cell-based therapies, stent retrievers, acupuncture with Western medicines, autologous bone marrow stromal cells, antiplatelet agents (aspirin, clopidogrel, and tirofiban), statins, and Western medicines with blood-activating and stasis-dispelling herbs (NaoShuanTong capsule, Ginkgo biloba, Tongqiao Huoxue Decoction, Xuesaitong injection) can improve the neurological deficits and activities of daily living, and the adverse effects were mild for the treatment of ischemic stroke. Moreover, ligustrazine, safflower yellow, statins, albumin, colchicine, MLC601, salvianolic acids, and DL-3-n-butylphthalide showed serious adverse events, intracranial hemorrhage, or mortality in ischemic stroke patients.

Conclusion: Our study demonstrated that tPA, edaravone and tPA, tPA and MTE, acupuncture and Western medicines, and blood-activating and stasis-dispelling herbs with Western medicines are the optimum neurological function and activities of daily living medication for patients with ischemic stroke.

Systematic Review Registration: https://inplasy.com/, identifier [INPLASY202250145].

Comparison of stent retriever thrombectomy using 3-dimensional patient-specific models of intracranial circulation with actual middle cerebral artery occlusion thrombectomy cases

BACKGROUND AND PURPOSE

Stent retriever (SR) thrombectomy is commonly used for the treatment of emergent large vessel occlusion (ELVO) in acute ischemic stroke. Clot imaging parameters such as clot length, diameter, distance to the internal carotid artery terminus, and vessel angle where the SR is deployed may predict the likelihood of achieving first pass effect (FPE). Most of the proposed factors that seem to affect recanalization success have been studied individually, and conflicting data derived from clinical versus in vitro studies using 3-dimensional printed models of intracranial circulation currently exist.

METHODS

Using patient-specific 3-dimensional phantoms of the cervical and intracranial circulation, we simulated middle cerebral arteries (MCA) M1 and M2 occlusions treated with SR thrombectomy using Solitaire (Medtronic) or Trevo (Styker). Our primary outcome was FPE, defined as Thrombolysis in Cerebral Infarction score of 2c-3 achieved after a single thrombectomy attempt. We also performed retrospective analysis of same clot imaging characteristics of consecutive cases of MCA occlusion and its association with FPE matching the 3-dimensional in vitro experiments. Analysis was conducted using IBM SPSS Statistics Version 25 (IBM Corp., Armonk, NY). Chi-square tests and bivariate logistic regressions were the main statistical tests used in analysis. A p-value of less than .05 was considered to indicate statistical significance. Ninety-five confidence intervals (95% CI) were generated.

RESULTS

We compared 41 thrombectomy experiments performed using patient-specific 3-dimensional in vitro models with a retrospective cohort of 41 patients treated with SR thrombectomy. We found that in the in vitro cohort, higher MCA angulation was associated with a lower likelihood of FPE (odds ratio [OR] = 0.967, 95% CI = 0.944-0.991, p = .008). Meanwhile in the in vivo cohort, higher MCA angulation was associated with a higher likelihood of FPE (OR = 1.039, 95% CI = 1.003-1.077, p = .033). Neither clot length nor location of clot (M1 vs. M2) was associated with a difference in FPE rates in either cohort.

DISCUSSION

Comparison of SR thrombectomy performed during actual MCA occlusion cases versus patient-specific 3-dimensional replicas revealed MCA angulation as an independent predictor of procedure success or failure. However, the opposite direction of effect was observed between the two studied environments, indicating potential limitations of studying SR thrombectomy using 3-dimensional models of LVO.

Direct angiographic intervention for acute ischemic stroke with large vessel occlusion

Background:Rapid and effective revascularization is the cornerstone of acute ischemic stroke treatment. Endovascular thrombectomy reperfusion has dramatically changed patients' outcomes with large vessel occlusions. Results of randomized controlled trials have shown that the benefit of this treatment is highly time-sensitive. The purpose of this review is to introduce a new approach to acute stroke treatment - direct angiographic intervention for selected patients. Methods & Results:We examined the issues related to the current guideline-based practice, emphasizing whether the benefit of using advanced multimodal imaging is worth the potential resultant disability generated by delayed reperfusion times. The published evidence supporting this novel concept was reviewed, its safety and feasibility discussed, and appropriate predictive tools for patient selection explored.Conclusion:This new approach may provide benefits for appropriately selected patients. Further prospective trials are needed to clarify the risk-versus-benefit of this approach.Abbreviations and Acronyms: AHA: American Heart AssociationAIS: acute ischemic strokeASA: American Stroke AssociationASPECTS: Alberta Stroke Program Early Computed Tomography ScoreCT: computed tomographyCTA: computed tomography angiographyCTP: computed tomography perfusionDMVO: distal, medium vessel occlusionDSA: digital subtraction angiographyED: Emergency DepartmentEVT: endovascular thrombectomyFD: flat detectorIA: intra-arterialIV: intravenousICH: intracerebral hemorrhageMR: magnetic resonanceMRA: magnetic resonance angiographyMSU: mobile stroke unitNIHSS: National Institutes of Health Stroke ScaleNCCT: non-contrast computed tomographyPLVO: proximal, large vessel occlusionPPV: positive predictive valuePWI: magnetic resonance perfusion-weighted imaging.

RECO Flow Restoration Device Versus Solitaire FR With the Intention for Thrombectomy Study (REDIRECT): a prospective randomized controlled trial

OBJECTIVE

The RECO flow restoration (FR) device is a new stent retriever designed for rapid flow restoration in acute ischemic stroke (AIS) caused by large vessel occlusion (LVO). Here, the authors compared the efficacy and safety of the RECO device with the predicate Solitaire FR stent retriever.

METHODS

The RECO Flow Restoration Device Versus Solitaire FR With the Intention for Thrombectomy Study (REDIRECT) was a multicenter, prospective, open randomized controlled trial. Patients with acute LVO at 7 Chinese stroke centers participated in the study. The primary efficacy endpoint was defined as a modified thrombolysis in cerebral infarction (mTICI) reperfusion grade ≥ 2 within three passes. The primary safety endpoint comprised any serious adverse device effect, symptomatic intracerebral hemorrhage (sICH), and any serious adverse event (SAE; defined as cerebral palsy or death) within 24 hours after the procedure. The secondary efficacy endpoints consisted of functional independence (modified Rankin Scale score 0-2), procedure duration, and 90-day all-cause mortality.

RESULTS

Between January 2014 and August 2016, 67 patients were randomly allocated to the RECO group and 69 patients to the Solitaire FR group. The primary efficacy endpoint (mTICI grade ≥ 2 within three passes) was similar in the two treatment groups (91% vs 87%, respectively, p = 0.5861), and the rate of reperfusion with an mTICI grade 2b/3 was 87% versus 75% (p = 0.1272). There were no serious adverse device effects in any patient. The rates of sICH (1.5% vs 7.2%, p = 0.1027) and SAEs (6.0% vs 1.4%, p = 0.2050) within 24 hours after the procedure were similar in the two treatment groups. There was no significant difference in the rate of functional independence (63% vs 46%, p = 0.0609) or 90-day all-cause mortality (13% vs 23%, p = 0.1848) or in procedure duration (85.39 ± 47.01 vs 89.94 ± 53.34 minutes, p = 0.5986) between the two groups.

CONCLUSIONS

The RECO stent retriever is effective and safe as a mechanical thrombectomy device for AIS due to LVO. Clinical trial registration no.: NCT01983644 (clinicaltrials.gov).

Why we fail: mechanisms and co-factors of unsuccessful thrombectomy in acute ischemic stroke

Purpose

Mechanical thrombectomy (MT) is an effective treatment for patients suffering from acute ischemic stroke. However, recanalization fails in about 16.5% of interventions. We report our experience with unsuccessful MT and analyze technical reasons plus patient-related parameters for failure.

Methods

Five hundred ninety-six patients with acute ischemic stroke in the anterior circulation and intention to perform MT with an aspiration catheter and/or stent retriever were analyzed. Failure was defined as 0, 1, or 2a on the mTICI scale. Patients with failing MT were analyzed for interventional progress and compared to patients with successful intervention, whereby parameters included demographics, medical history, stroke presentation, and treatment.

Results

One hundred of the 596 (16.8%) interventions failed. In 20 cases, thrombus could not be accessed or passed with the device. Peripheral arterial occlusive disease is common in those patients. In 80 patients, true stent retriever failure occurred. In this group, coagulation disorders are associated with poor results, whereas atrial fibrillation is associated with success.

The administration of intravenous thrombolysis and intake of nitric oxide donors are associated with recanalization success. Intervention duration was significantly longer in the failing group.

Conclusion

In 20% of failing MT, thrombus cannot be reached/passed. Direct carotid puncture or surgical arterial access could be considered in these cases.

In 80% of failing interventions, thrombus can be passed with the device, but the occluded vessel cannot be recanalized. Rescue techniques can be an option. Development of new devices and techniques is necessary to improve recanalization rates. Assessment of pre-existing illness could sensitize for occurring complications.

Comparison of the efficacy and safety of thrombectomy devices in acute stroke : a network meta-analysis of randomized trials

Introduction

Mechanical thrombectomy (MT) is increasingly used for large-vessel occlusions (LVO), but randomized clinical trial (RCT) level data with regard to differences in clinical outcomes of MT devices are limited. We conducted a network meta-analysis (NMA) that enables comparison of modern MT devices (Trevo, Solitaire, Aspiration) and strategies (stent retriever vs aspiration) across trials.

Methods

Relevant RCTs were identified by a systematic review. The efficacy outcome was 90-day functional independence (modified Rankin Scale (mRS) score 0–2). Safety outcomes were 90-day catastrophic outcome (mRS 5–6) and symptomatic intracranial hemorrhage (sICH). Fixed-effect Bayesian NMA was performed to calculate risk estimates and the rank probabilities.

Results

In a NMA of six relevant RCTs (SWIFT, TREVO2, EXTEND-IA, SWIFT-PRIME, REVASCAT, THERAPY; total of 871 patients, 472 Solitaire vs medical-only, 108 Aspiration vs medical-only, 178 Trevo vs Merci, and 113 Solitaire vs Merci) with medical-only arm as the reference, Trevo had the greatest functional independence (OR 4.14, 95% credible interval (CrI) 1.41–11.80; top rank probability 92%) followed by Solitaire (OR 2.55, 95% CrI 1.75–3.74; top rank probability 72%). Solitaire and Aspiration devices had the greatest top rank probability with respect to low sICH and catastrophic outcomes (76% and 91%, respectively), but without significant differences between each other. In a separate network of seven RCTs (MR-CLEAN, ESCAPE, EXTEND-IA, SWIFT-PRIME, REVASCAT, THERAPY, ASTER; 1737 patients), first-line stent retriever was associated with a higher top rank probability of functional independence than aspiration (95% vs 54%), with comparable safety outcomes.

Conclusions

These findings suggest that Trevo and Solitaire devices are associated with a greater likelihood of functional independence whereas Solitaire and Aspiration devices appear to be safer.

Mechanical thrombectomy using the Solitaire stent in a left main coronary artery: A novel approach to coronary thrombus retrieval

The Solitaire stent is a self-expanding nitinol, fully retrievable stent that was originally designed for applications in cerebral circulation. Expanded indications for its use in mechanical embolectomy during acute ischemic stroke have proven safe and effective. Herein, we describe a novel use of this stent to perform a mechanical thrombectomy of a large left main coronary artery thrombus. © 2016 Wiley Periodicals, Inc.

A model for priority setting of health technology assessment: the experience of AHP-TOPSIS combination approach

BACKGROUND

In recent times, the use of health technologies in the diagnosis and treatment of diseases experienced considerable and accelerated growth. The goal of the present study was to describe the designated pilot MCDM (Multiple Criteria Decision Making) model for priority setting of health technology assessment in Iran.

METHODS

Relevant articles were sought and retrieved from the most appropriate medical databases, including the Cochrane Library, PubMed and Scopus via three separate search strategies, using MESH and free text until March, 2015. Retrieved criteria were questioned from health technology assessment experts in two rounds and the relative weight for valid criteria was finally obtained from paired wise comparison method. After extraction of relative weights based on the aforementioned procedure, TOPSIS (The Technique for Order of Preference by Similarity to Ideal Solution) priority setting model was designed. The stated model was applied for assessing three technologies (adenosine, tissue plasminogen activator and mechanical thrombectomy) which were available for projects call of Iranian health technology assessment department in order to determine applicability of the model for practical purpose.

RESULTS

Nine criteria, including efficiency/effectiveness, safety, population size, vulnerable population size, availability of alternative technologies, cost effectiveness in other countries, budget impact, financial protection, quality of evidence, were extracted by the Iranian health technology assessment experts. The relative weights of these criteria were as follows 0.12, 0.2, 0.06, 0.08, 0.08, 0.13, 0.08, 0.09, and 0.15, respectively. Finally TOPSIS pilot model was designed by three health technologies and nine criteria relative weights. Results showed that, the applicability of the stated model was suitable and as the pilot testing, tissue plasminogen activator was the first priority, adenosine was second and mechanical thrombectomy was third for performing health technology assessment by the Iranian ministry of health and medical education.

CONCLUSION

According to the results of this study, this model with nine effective criteria and their relative weights and in combination with TOPSIS approach could be used with suitable applicability by health technology assessment department in deputy of curative affairs and food and drug organization for determination of research priorities in health technology assessment.