Single-center experience of cerebral artery thrombectomy using the TREVO device in 60 patients with acute ischemic stroke

Effectiveness and safety of the Trevo® Retriever for mechanical thrombectomy in Chinese patients with acute ischemic stroke: Trevo Retriever China Registry

BACKGROUND

To quantify the effectiveness and safety of the Trevo® Retriever for endovascular treatment of acute ischemic stroke (AIS) patients in China.

METHODS

Trevo Retriever Registry (China) was a prospective, multicenter, non-comparative, open-label study of patients with AIS treated with the Trevo Retriever. The primary outcome was the proportion of patients achieving an expanded Thrombolysis in Cerebral Infarction (eTICI) score ≥2b at the end of endovascular treatment. Secondary outcomes included first-pass eTICI score ≥2b and 90-day modified Rankin Scale (mRS) score ≤2.

RESULTS

The Trevo Retriever Registry (China) enrolled and followed 201 patients (62.1 ± 12.5 years-old; 70.6% male) at 11 centers. The pre-procedure NIHSS score and ASPECTS were 16 (interquartile range (IQR), 13-21) and 7 (IQR, 6-9), respectively, and 188 (93.5%) patients had an mRS score of 0 prior to the stroke. The main stroke etiology was large artery atherosclerosis, accounting for 71.6% (144/201) of patients. Post-procedure eTICI ≥2b was 98.4% (187/190). First-pass eTICI ≥2b was 74.7% (136/182). The 90-day good outcome (mRS ≤2) rate was 73.6% (148/201). The 90-day all-cause mortality was 5.5% (11/201). Neurological deterioration at 24 h post-procedure was observed in 7.7% (15/195) patients. Embolism in a new territory was seen in one patient (0.5%). Two (1.0%) procedure-related adverse events (AEs) occurred, which were intra-procedure cerebral artery embolism. No Trevo related AEs occurred.

CONCLUSIONS

This real-world study of the Trevo Retriever in China demonstrated a high rate of revascularization and first-pass success that resulted in an overall high good function outcome rate and low mortality.

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 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.

Cost-effectiveness analysis of mechanical thrombectomy with stent retriever in the treatment of acute ischemic stroke in Italy

BACKGROUND

Stroke has a significant disease burden in terms of acute and long-term disability in Italy and throughout the world. Endovascular treatments for the management of a stroke event have been coupled in the past years with the possibility to mechanically remove the occlusion by means of specially designed thrombectomy devices, and their exclusive use showed levels of effectiveness in line with those of the existing pharmacological treatments.

OBJECTIVE

To assess the cost-effectiveness of mechanical thrombectomy (MT) with the Solitaire Revascularization Device (stent retriever) for the treatment of acute ischemic stroke (AIS) in patients with large vessel occlusions (LVOs), comparing MT plus intravenous tissue plasminogen activation (MT plus IV t-PA) vs IV t-PA alone, in Italy.

METHODS

A Markov model was used to simulate costs and benefits of MT plus IV t-PA and IV t-PA alone over a 5-year time horizon and considering the perspective of the Italian National Health Service (NHS). Results are reported in terms of Incremental Cost Effectiveness Ratio (ICER). Deterministic and probabilistic sensitivity analyses are carried out in order to test the robustness of the results.

RESULTS

Total costs of MT plus IV t-PA and IV t-PA alone are equal to €31,798 and €34,855, respectively. The MT allows incremental QALYs for 0.77, determining a dominant ICER. The utilities associated to the mRS health states are the parameters with the highest impact on the results. Multiway sensitivity analyses determined a 90% probability of dominance.

CONCLUSIONS

MT plus IV t-PA for AIS patients with LVO is cost-effective from year 1 through year 3, and cost-saving from year 4 onward in the Italian context, achieving better results, both in terms of efficacy and in terms of resource consumption.

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.

Intraprocedural predictors of post-stent retriever thrombectomy subarachnoid hemorrhage in middle cerebral artery stroke

BACKGROUND

Stent retriever thrombectomy (SRT) in acute thromboembolic stroke can result in post-thrombectomy subarachnoid hemorrhage (PTSAH). Intraprocedural findings associated with PTSAH are not well defined.

OBJECTIVE

To identify angiographic findings and procedural factors during SRT that are associated with PTSAH.

MATERIALS AND METHODS

This was a retrospective, observational cohort study of consecutive patients with middle cerebral artery (MCA) acute ischemic stroke treated with SRT. Inclusion criteria were: (1) age ≥18 years; (2) thromboembolic occlusion of the MCA; (3) at least one stent retriever pass beginning in an M2 branch; (4) postprocedural CT or MRI scan within 24 hours; (5) non-enhanced CT Alberta Stroke Program Early CT Score >5. Exclusion criteria included multi-territory stroke before SRT.

RESULTS

Eighty-five patients were enrolled; eight patients had PTSAH (group 1) and 77 did not (group 2). Baseline demographic and clinical characteristics were comparable between the two groups. In group 1, a significantly greater proportion of patients had more than two stent retriever passes (62.5% vs 18.2%, P=0.01), a stent retriever positioned ≥2 cm along an M2 branch (100% vs 30.2%, P=0.002), and the presence of severe iatrogenic vasospasm before SRT pass (37.5% vs 5.2%, P=0.02). One patient with PTSAH and associated mass effect deteriorated clinically.

CONCLUSIONS

An increased number of stent retriever passes, distal device positioning, and presence of severe vasospasm were associated with PTSAH. Neurological deterioration with PTSAH can occur.

Efficacy and Safety of REVIVE SE Thrombectomy Device for Acute Ischemic Stroke: River JAPAN (Reperfuse Ischemic Vessels with Endovascular Recanalization Device in Japan)

REVIVE SE (REVIVE) is a closed-ended, self-expanding stent retriever used in the RIVER JAPAN study. We present our early experience with REVIVE for revascularization of acute ischemic stroke (AIS) in patients who have failed or are ineligible for intravenous recombinant tissue plasminogen activator treatment. This prospective, single-arm, non-randomized, multicenter registry study followed up patients undergoing mechanical thrombectomy with REVIVE for 90 days. The primary endpoint was a post-procedure Thrombolysis in Cerebral Infarction (TICI) score ≥2a. Secondary endpoints were clot migration/embolization; recanalization without symptomatic intracranial hemorrhage (ICH) at 24 h; symptomatic ICH; good neurological outcome (modified Rankin Scale score ≤2 National Institute of Health Stroke Scale (NIHSS) score decrease ≥10) at day 90; device- or procedure-related serious adverse events (SAEs) and mortality at day 90. To confirm non-inferiority of REVIVE, results were compared with historical data of the Merci Retriever. About 49 patients were enrolled (median age 73 years; males 46.9%; middle cerebral artery (MCA) occlusion 83.7%; median NIHSS score 17). A post-procedure TICI score ≥2a was observed in 73.5% (36/49, 95% confidence interval [CI] 58.9–85.1) of patients. No post-procedural clot migration/embolization events occurred. Successful recanalization without symptomatic ICH was observed in 62.5% (30/48, 95% CI 47.4–76.0). The good neurological outcome was achieved in 66.7% (32/48) patients. Symptomatic ICH and device- or procedure-related SAEs were reported in 6.3% and 12.2% of patients, respectively. Two deaths were reported. REVIVE demonstrated equivalent efficacy and safety as the Merci Retriever. Results suggest that REVIVE is effective and safe in recanalizing occluded intracranial arteries in AIS.

Use of a complete autologous blood recovery system (the Sorin Xtra® Autotransfusion System) during mechanical thrombectomy of extensive cerebral venous sinus thrombosis

Background The endovascular therapy for cerebral venous sinus thrombosis (CVST) is currently accepted as a second-line treatment for patients who have failed or those in whom systemic anticoagulation is contraindicated or in a subgroup of patients presenting with rapid neurologic deterioration. A number of different mechanical and pharmacologic endovascular strategies have been reported, either as separate or combined approaches. These new catheters and aspiration systems have a high power and vacuum capacity, which carries a risk of anemization of the patient and hypovolemic shock, being necessitating the transfusion of the patient. Material and methods Because of the problems that donor blood transfusion can bring, we describe the use of a Sorin Xtra® Autotransfusion System (ATS). This complete autologous blood recovery system was designed for use in procedures where medium- to high-volume blood loss occurs, such as major surgeries. We have adapted it to recover all the blood aspirated during the mechanical thrombectomy procedures of the dural cerebral venous sinuses, since they are procedures that can cause a significant loss of blood. One advantage to this is the patient receives his or her own blood instead of donor blood, so there is no risk of contracting outside diseases or transfusion reactions. Conclusions This technical note describes a novel and previously unpublished technical approach to CVST that can be immediately applied to clinical practice. It also raises awareness among the interventional neuroradiologist and anesthesiologist communities about novel, potentially lifesaving endovascular treatments in patients with extensive CVST.

Plasmin (Human) Administration in Acute Middle Cerebral Artery Ischemic Stroke: Phase 1/2a, Open-Label, Dose-Escalation, Safety Study

BACKGROUND

This phase 1/2a, open-label, multicenter, dose-escalation, safety study describes the first evaluation of plasmin as an intracranial thrombolytic treatment for acute ischemic stroke in the middle cerebral artery. The rationale for intrathrombus administration is that plasmin would bind fibrin inside the targeted clot, protecting it from circulating inhibitors.

METHODS

Plasmin was given in escalating doses within 9 hours of stroke onset, and treatment efficacy was determined in 5 patient cohorts (N = 40): cohort 1 (20 mg, .5 mL/min), cohort 2a (40 mg, .05 mL/min), cohort 2b (40 mg, .33 mL/min), cohort 3a (80 mg, .67 mL/min), and cohort 3b (80 mg, .33 mL/min).

RESULTS

Plasmin was generally safe at doses as high as 80 mg. No symptomatic intracranial hemorrhage was observed, and the rate of asymptomatic intracranial hemorrhage (12.5%) was consistent with that expected under supportive care. No relationship was observed between the plasmin dose and the incidence or severity of bleeding events, any particular serious adverse events, nor death. Changes in clinical chemistry, hematology, and coagulation parameters following plasmin treatment were unremarkable and unrelated to the dose. Plasmin administration resulted in successful reperfusion of the occluded vessel in 25% of patients across all cohorts, with no relationship between successful perfusion and total plasmin dose but a potential increase in reperfusion with slower infusion rates.

CONCLUSIONS

Plasmin treatment of the occluded middle cerebral artery within 9 hours of stroke onset was well tolerated and did notincrease adverse outcomes; however, successful recanalization was achieved in only a limited number of patients.

Prevention, management, and rehabilitation of stroke in low- and middle-income countries

Although stroke incidence in high-income countries (HICs) decreased over the past four decades, it increased dramatically in low- and middle-income countries (LMICs). In this review, we describe the current status of primary prevention, treatment, and management of acute stroke and secondary prevention of and rehabilitation after stroke in LMICs. Although surveillance, screening, and accurate diagnosis are important for stroke prevention, LMICs face challenges in these areas due to lack of resources, awareness, and technical capacity. Maintaining a healthy lifestyle, such as no tobacco use, healthful diet, and physical activity are important strategies for both primary and secondary prevention of stroke. Controlling high blood pressure is also critically important in the general population and in the acute stage of hemorrhagic stroke. Additional primary prevention strategies include community-based education programs, polypill, prevention and management of atrial fibrillation, and digital health technology. For treatment of stroke during the acute stage, specific surgical procedures and medications are recommended, and inpatient stroke care units have been proven to provide high quality care. Patients with a chronic condition like stroke may require lifelong pharmaceutical treatment, lifestyle maintenance and self-management skills, and caregiver and family support, in order to achieve optimal health outcomes. Rehabilitation improves physical, speech, and cognitive functioning of disabled stroke patients. It is expected that home- or community-based services and tele-rehabilitation may hold special promise for stroke patients in LMICs.

The pREset Stent Retriever for Endovascular Treatment of Stroke Caused by MCA Occlusion: Safety and Clinical Outcome

PURPOSE

The purpose of this study was to analyze the safety and efficacy of the pREset device, a stent retriever system, for endovascular mechanical thrombectomy (MT) in acute ischemic stroke (AIS) after middle cerebral artery (MCA) occlusion.

METHODS

Retrospectively, 48 consecutive patients (mean age ± standard deviation, 71.0 ± 11.9 years; 24 women) treated for acute MCA occlusion using pREset solely or in combination with other MT devices were identified. Recanalization success was evaluated using the modified thrombolysis in cerebral infarction score (TICI), and complications were detected by 24-h follow-up computed tomography or magnetic resonance imaging. MCA anatomy was assessed in angiograms. Clinical outcome was evaluated with National Institutes of Health Stroke Scale (NIHSS) score at admission and discharge, and modified Rankin scale (mRS) score at discharge and follow-up.

RESULTS

Successful recanalization (TICI 2b/3) was achieved in 39 patients (81.3 %). Rate of procedure-related complications was 8.3 %. In four patients, a subarachnoid hemorrhage occurred (8.3 %), and parenchymal hematoma was detected in four patients (8.3 %). None of those events was associated with clinical deterioration. MCA curvature significantly influenced recanalization success (P < 0.005). Successful recanalization correlated significantly with lower NIHSS scores and favorable clinical outcome (mRS score 0-2) at discharge (P < 0.05). Mortality within 90 days was significantly lower in patients with TICI 2b/3 (P < 0.005).

CONCLUSIONS

High recanalization rates, low complication rates, and a significantly improved outcome after successful recanalization strongly suggest that MT with pREset is an adequate therapy for AIS after MCA occlusion. Vessel curvature is a significant determining factor for recanalization success.

Direct Microsurgical Embolectomy for Acute Occlusion of the Internal Carotid Artery and Middle Cerebral Artery

BACKGROUND

Surgical embolectomy is the most promising therapy for physically removing emboli from major cerebral arteries. However, it requires an experienced surgical team, time-consuming steps, and is not incorporated into acute stroke therapy.

METHODS

We established seamless collaboration between services, refined surgical techniques, and conducted a prospective trial of emergency surgical embolectomy. Surgical indications included the presence of acute hemispheric symptoms, absence of low-density area on computed tomography, evidence of internal carotid artery terminus or proximal middle cerebral artery occlusion, and availability of resources to start surgery within 3 hours of symptom onset. The indications were confirmed by an interdisciplinary team. We assessed revascularization rates, time from admission to surgery and from surgery to recanalization, procedural complications, and clinical outcomes.

RESULTS

Between 2005 and 2014, 14 consecutive patients with acute proximal middle cerebral artery or internal carotid artery terminus occlusion underwent emergency surgical embolectomy. All patients showed complete recanalization. Twelve patients survived and 7 had fair functional outcome (Rankin Scale score, ≤3). No significant procedural adverse events occurred. The mean times from admission to start of surgery, from surgery to recanalization, and from onset to recanalization were 14 minutes, 79 minutes, and 223 minutes, respectively.

CONCLUSIONS

Our results suggest that microsurgical embolectomy can rapidly, safely, and effectively retrieve clots and deserves reappraisal, although the choice largely depends on local institutional expertise.

Metabolic Syndrome Predicts Refractoriness to Intravenous Thrombolysis in Acute Ischemic Stroke

BACKGROUND

Metabolic syndrome (MetS) has been associated with higher resistance to clot lysis at 24 hours after tissue plasminogen activator (tPA) administration in patients with acute ischemic stroke. We aimed to test this hypothesis at earlier time points, when neurointerventional rescue procedures may still be indicated to achieve arterial recanalization.

METHODS

This is a prospective and observational study in consecutive stroke patients with MCA occlusion treated with IV tPA. MetS was diagnosed following the unified criteria of the last Joint Interim Statement 2009 participating several major organizations. The primary outcome variable was resistance to thrombolysis, defined as the absence of complete middle cerebral artery recanalization 2 hours after tPA bolus assessed by transcranial color-coded duplex or when rescue mechanical thrombectomy after IV tPA was required. Secondary outcome variables were dramatic neurological improvement (decrease in ≥10 points, or a National Institutes of Health Stroke Scale [NIHSS] score of 0-1 at 24 hours), symptomatic intracerebral hemorrhage following European-Australasian Acute Stroke Study II criteria, infarct volume at 24 hours (calculated by using the formula for irregular volumes, ABC/2), and good outcome (modified Rankin Scale score < 3) at 3 months.

RESULTS

A total of 234 patients (median baseline NIHSS score 16 [10-20]) were included and 146 (62.4%) fulfilled MetS criteria. After multivariate analysis, MetS emerged as an independent predictor of resistance to thrombolysis (odds ratio = 2.2 [1.3-4.2], P = .01) and absence of dramatic neurological improvement (odds ratio = .5 [.28-.97], P = .04). In addition, MetS conferred poorer functional outcome, higher symptomatic intracerebral hemorrhage rate, and increased infarct volume, although these associations disappeared after adjustment for covariates.

CONCLUSIONS

MetS predicts patients with middle cerebral artery occlusion refractory to early clot dissolution after IV tPA. This finding may help in acute clinical decision-making.

Stent Retriever Thrombectomy in Patients Who Are Ineligible for Intravenous Thrombolysis: A Multicenter Retrospective Observational Study

BACKGROUND AND PURPOSE

Intravenous thrombolysis with rtPA is the standard of care for patients with acute ischemic stroke within 4.5 hours after symptom onset. However, a considerable number of patients are ineligible for IV thrombolysis due to various contraindications. Recent studies have proved the superiority of mechanical thrombectomy for patients with large-vessel occlusions in combination with IV rtPA compared with IV rtPA alone. We aimed to demonstrate the efficacy of mechanical thrombectomy for patients who are ineligible for IV rtPA.

MATERIALS AND METHODS

Patients from the stroke registries of 4 dedicated centers who were treated with mechanical thrombectomy from January 2010 to October 2014 were retrospectively evaluated. Inclusion criteria were the following: acute stroke due to proved large-artery occlusion, ineligibility for IV thrombolysis, and a timeframe of ≤4.5 hours between stroke and the start of mechanical thrombectomy. Recanalization success, periprocedural complications, clinical outcome, and hemorrhages were evaluated.

RESULTS

One hundred thirty endovascular recanalization procedures were identified. The locations were the following: proximal ICA in 17 (13.1%), terminus ICA in 25 (19.2%), M1 segment in 77 (59.2%), and M2 segment in 11 (8.5%). TICI 2b/3 results were achieved in 101 (77.7%), and an mRS score of 0-2 in 47 patients (37.9%). There was a significant correlation between TICI 2b/3 results and good clinical outcomes (87.2% versus 6.8%; P = .048). A good clinical result was most frequent when recanalization was achieved within 4.5 hours (37/74 = 50% versus 10/50 = 20.0%; P = .001). Symptomatic hemorrhage occurred in 13.1% of patients; mortality was 24.2%. Periprocedural complications were recorded in 10 patients (7.7%).

CONCLUSIONS

Mechanical thrombectomy can achieve good clinical outcomes in patients with acute large-artery occlusion ineligible for IV thrombolysis, in particular when recanalization is reached early.

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

BACKGROUND AND PURPOSE

Intravenous thrombolysis and mechanical thrombectomy predominantly using stent retrievers have been shown to effectively restore cerebral blood flow and improve functional outcome in patients with acute ischemic stroke. We sought to determine the safety and feasibility of mechanical thrombectomy using the new ERIC retrieval device.

MATERIALS AND METHODS

We identified 36 consecutive patients from our Stroke Center registry with acute ischemic stroke who were treated with the new ERIC retriever from September 2013 to December 2014. Patients with ischemic stroke meeting the following criteria were eligible: onset-to-treatment time of ≤4.5 hours or wake-up stroke (n = 10) with relevant CT perfusion mismatch, NIHSS score of ≥4, and proof of large-vessel occlusion in the anterior circulation on CT angiography. We assessed the baseline characteristics including age, sex, comorbidities, stroke severity, site of vessel occlusion, presence of tissue at risk, and treatment-related parameters such as onset-to-treatment time, recanalization grade, and outcome.

RESULTS

The mean age was 70 ± 13 years, and the median NIHSS score on admission was 18 (interquartile range, 10-20). Seventeen of 36 patients were on platelet inhibitors or anticoagulants before endovascular treatment (47.2%); 20 patients received intravenous thrombolysis (55.5%). The ERIC was used as the sole retriever in 28 patients (77.8%) and as a rescue device in 8. Excellent recanalization was achieved in 30/36 patients (83.3%) with TICI 3 in 19/36 and 2b in 11/36, respectively. Median procedural time in these patients was 90 minutes (interquartile range, 58-133 minutes). No intraprocedural complications occurred.

CONCLUSIONS

In this observational study, the new ERIC retrieval device was technically feasible, safe, and effective in acute ischemic stroke with large-vessel occlusion.

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

BACKGROUND

The treatment of choice for acute ischaemic stroke is the intravenous administration of recombinant tissue plasminogen activator within 3-4.5 h of symptom onset. However, the use of a thrombolytic would be limited by its narrow therapeutic window and contraindications. As a result, in recent years, techniques such as mechanical thrombectomy have emerged, which employ thrombus retrieval devices, such as stent retrievers (Solitaire™, Trevo® or Revive™), whose safety and efficacy in the endovascular treatment of acute ischaemic stroke is analysed in this article.

METHODS

A systematic literature search was undertaken until March 2015. The quality of evidence was assessed according to the GRADE methodology. A meta-analysis of the results of randomised controlled trials (RCTs) was performed, and the weighted average for the case series' sample size was calculated (Review Manager v5.2 and SPSS v19).

RESULTS

Seventeen primary studies (2 RCTs, Solitaire™ and Trevo® vs. Merci®, and 15 case series) were selected. The RCT results show that stent retrievers have a safety profile similar to the Merci® device. However, both Solitaire™ and Trevo® achieved a higher recanalisation success rate (OR, 4.56; 95% CI, 2.63-7.90; p < 0.00001) and appropriate clinical outcome at 90 days (OR, 2.54; 95% CI, 1.52-4.25; p < 0.0004), although the 90-day mortality rate was similar in both groups (OR, 0.75; 95% CI, 0.17-3.37; p = 0.70).

CONCLUSIONS

Stent retrievers appear to be safe and effective devices, achieving high recanalisation rates and good clinical outcomes in the endovascular treatment of patients with acute ischaemic stroke due to the occlusion of intracranial arteries in comparison with the clot retriever Merci®.

Mechanical thrombectomy with the Trevo ProVue device in ischemic stroke patients: does improved visibility translate into a clinical benefit?

PURPOSE

To investigate the efficacy and safety of the Trevo ProVue (TPV) stent retriever in stroke patients with large artery occlusions, with particular attention to the full structural radiopacity of the TPV.

MATERIALS AND METHODS

Case files and images of TPV treatments were reviewed for clinical and technical outcome data, including revascularization rates, device and procedure related complications, and outcome at discharge and after 90 days.

RESULTS

76 patients were treated with TPV. Mean National Institutes of Health Stroke Scale (NIHSS) score was 18 and 68% had additional intravenous thrombolysis. 63 occlusions were in the anterior circulation: 44 M1 (58%), 8 M2 (11%), 8 internal carotid artery-terminus (11%), 2 internal carotid artery- left (3%), 1 A2 (1%), and 13 vertebrobasilar (17%). 58 of 76 (76%) were solely treated with TPV; the remainder were treated with additional stent retrievers. Mean number of passes in TPV only cases was 2.2 (SD 1.2). In rescue cases, 3.2 (SD 2.2) passes were attempted with the TPV followed by 2.6 rescue device passes (SD 2). TPV related adverse events occurred in 4/76 cases (5%) and procedural events in 6/76 cases (8%). Mean procedural duration was 64 min (SD 42). Thrombolysis in Cerebral Infarction (TICI) 2b/3 recanalization was achieved in 69/76 patients (91%), including 50% TICI 3. Of 56 survivors (74%), 37 (49%) showed a favorable outcome at 90 days (Solitaire With the Intention for Thrombectomy trial criteria), statistically associated with age, baseline NIHSS, onset to revascularization time, and TICI 2b-3 reperfusion. TPV radiopacity allowed for visual feedback, changing the methodology of stent retriever use in 44/76 cases (58%).

CONCLUSIONS

Neurothrombectomy with TPV is feasible, effective, and safe. The recanalization rate compares favorably with reported data in the literature. Improved structural radiopacity may facilitate neurothrombectomy or influence the course of action during retrieval.

Treatment of acute stroke: an update

Stroke is the second leading cause of global mortality after coronary heart disease, and a major cause of neurological disability. About 17 million strokes occur worldwide each year. Patients with stroke often require long-term rehabilitation following the acute phase, with ongoing support from the community and nursing home care. Thus, stroke is a devastating disease and a major economic burden on society. In this overview, we discuss current strategies for specific treatment of stroke in the acute phase, focusing on intravenous thrombolysis and mechanical thrombectomy. We will consider two important issues related to intravenous thrombolysis treatments: (i) how to shorten the delay between stroke onset and treatment and (ii) how to reduce the risk of symptomatic intracerebral haemorrhage. Intravenous thrombolysis has been approved treatment for acute ischaemic stroke in most countries for more than 10 years, with rapid development towards new treatment strategies during that time. Mechanical thrombectomy using a new generation of endovascular tools, stent retrievers, is found to improve functional outcome in combination with pharmacological thrombolysis when indicated. There is an urgent need to increase public awareness of how to recognize a stroke and seek immediate attention from the healthcare system, as well as shorten delays in prehospital and within-hospital settings.

Evolution of Endovascular Therapy in Acute Stroke: Implications of Device Development

Intravenous thrombolysis is an effective treatment for acute ischaemic stroke. However, vascular recanalization rates remain poor especially in the setting of large artery occlusion. On the other hand, endovascular intra-arterial therapy addresses this issue with superior recanalization rates compared with intravenous thrombolysis. Although previous randomized controlled studies of intra-arterial therapy failed to demonstrate superiority, the failings may be attributed to a combination of inferior intra-arterial devices and suboptimal selection criteria. The recent results of several randomized controlled trials have demonstrated significantly improved outcomes, underpinning the advantage of newer intra-arterial devices and superior recanalization rates, leading to renewed interest in establishing intra-arterial therapy as the gold standard for acute ischaemic stroke. The aim of this review is to outline the history and development of different intra-arterial devices and future directions in research.

Evaluation of the JRecan device for thrombus retrieval: efficacy and safety in a swine model of acute arterial occlusion

OBJECTIVE

To evaluate the recanalization efficacy and safety of a novel stent retriever in a swine model of acute arterial occlusion.

METHODS

The JRecan thrombectomy device, a stent retriever with a weaving stent design, was evaluated in 18 occluded cervicocerebral vessels of swine. The flow restoration effect immediately upon deployment, the reperfusion rate after retrieval, thromboembolic events, and complications were assessed. The histologic structure of the renal arteries after retriever passage was measured to further assess the safety of JRecan.

RESULTS

Immediate flow restoration was achieved in 66.7% of occlusions (12/18). The reperfusion rate was 94.4% (two Thrombolysis in Cerebral Infarction (TICI) 2b and 15 TICI 3). Distal thromboembolic events did not occur. Microscopic examination of the arteries after retrieval showed mild degrees of endothelial loss in 96.6% (29/30), fibrin or platelet deposition in 53.3% (16/30), and disruption of the internal elastic lamina in 10% (3/30), without severe pathologic lesions.

CONCLUSIONS

The JRecan is highly effective at clot removal with a favorable safety profile and merits further development as a stent retriever for the treatment of acute ischemic stroke.

Comparing perfusion CT evaluation algorithms for predicting outcome after endovascular treatment in anterior circulation ischaemic stroke

AIM

To analyse perfusion CT (PCT) evaluation algorithms for their predictive value for outcome after endovascular therapy (ET) in acute ischaemic stroke.

MATERIALS AND METHODS

Twenty-six patients were prospectively enrolled to undergo endovascular therapy for moderate to severe [National Institute of Health Stroke Scale (NIHSS) score of ≥5] anterior circulation stroke ≤6 h of onset. PCT datasets were evaluated according to three algorithms: visual mismatch estimate (VME), Alberta Stroke Programme Early CT Score (ASPECTS) perfusion, and quantitative perfusion ratios (QPRs: RCBF, RCBV) of cerebral blood flow (CBF) and volume (CBV). Results were correlated with outcome measures [NIHSS score at discharge, NIHSS score change until discharge (ΔNIHSSA/D), mRS at 90 days (mRS90d)] and compared with a matched control group.

RESULTS

Recanalization was achieved in 73%, median NIHSS score decreased from 14 to 5 at discharge. The treatment and control group did not differ by VME and ASPECTS perfusion, nor did VME correlate with any of the three outcome measures. ASPECTS perfusion was not predictive of any outcome measure in the ET group. RCBF and RCBV were associated with ΔNIHSSA/D in controls and, inversely, the ET group, but not with mRS90d. Receiver operating characteristic (ROC) analysis of RCBF (and RCBV) showed a positive predictive and negative predictive value of 87% (78%) and 74% (73%), respectively, for discriminating major neurological improvement (ΔNIHSSA/D <7 versus ≥7).

CONCLUSIONS

Implementation of QPRs for CBF and CBV are superior to clinically used VME and ASPECTS perfusion evaluation methods for predicting early outcome after ET for anterior circulation stroke.

State-of-the-art endovascular treatment of acute ischemic stroke

Stroke is the third leading cause of death in the USA. An estimated 795,000 new or recurrent stroke events occur annually, mostly ischemic in nature. Arterial recanalization and subsequent reperfusion performed shortly after symptom onset can help to restore brain function in acute ischemic stroke (AIS). The only treatment currently approved by the United States Food and Drug Administration is intravenous tissue plasminogen activator, administered within 4.5 h of symptom onset. However, this short window often precludes effective intervention. Mechanical neurothrombectomy devices offer many potential advantages over pharmacologic thrombolysis, including more rapid achievement of recanalization, enhanced efficacy in treating large-vessel occlusions, and a potentially lower risk of hemorrhagic events. The goal of this chapter is to describe the state-of-the-art neurothrombectomy devices and stenting techniques for endovascular treatment of acute ischemic stroke, as well as to highlight recent advances in reperfusion therapies. Ongoing clinical trials, some with randomized, controlled designs, are included.

Complications of the endovascular management of acute ischemic stroke

Acute ischemic stroke is a significant source of morbidity and mortality across the globe. Currently, the only US Food and Drug Administration approved medical treatment of acute ischemic stroke is intravascular (IV) alteplase. While IV thrombolysis has been shown to decrease morbidity and mortality from acute ischemic stroke, it is limited in both its efficacy in certain types of stroke, as well as in its generalizability. It has been shown that time to revascularization is one of the most important predictors of outcomes in acute ischemic stroke, and thus clinicians have turned to endovascular options in efforts to improve outcomes from stroke. Direct intra-arterial thrombolysis was one of the first of such efforts to improve efficacy rates and increase the timeline for thrombolytic therapy. More recently, investigators and clinicians have turned to newer endovascular options in attempts to further improve recanalization rates. Many different endovascular techniques have been employed and are growing exponentially in use. Examples include stenting, as well as mechanical thrombectomy with both older-generation devices and newer stent retrieval technology. While the majority of the literature focuses on the effectiveness of different techniques, such as recanalization rates and major overall outcomes such as death and disability, there is very little literature on the complications of the different techniques. The purpose of this article is to review the different forms of endovascular treatment of acute ischemic stroke and their associated complications.

Recanalization and Reperfusion Therapies of Acute Ischemic Stroke: What have We Learned, What are the Major Research Questions, and Where are We Headed?

Two placebo-controlled trials have shown that early administration of intravenous recombinant tissue plasminogen activator (rt-PA) after ischemic stroke improves outcomes up to 4.5 h after symptoms onset; however, six other trials contradict these results. We also know from analysis of the pooled data that benefits from treatment decrease as time from stroke onset to start of treatment increases. In addition to time, another important factor is patient selection through multimodal imaging, combining data from artery status, and salvageable tissue measures. Nonetheless, at the present time randomized controlled trials (RCTs) cannot demonstrate any beneficial outcomes for neuroimaging mismatch selection after 4.5 h from symptoms onset. By focusing on cases of large arterial occlusion, we know that recanalization is crucial, so endovascular treatment is an approach of interest. The use of intra-arterial thrombolysis was tested in two small RCTs that demonstrated clear benefits in terms of higher recanalization and also in clinical outcomes. But a new paradigm of stroke treatment may have begun with mechanical thrombectomy. In this field, Merci devices have been overtaken by fully deployed closed-cell self-expanding stents (stent-retrievers or “stent-trievers”). However, despite the high rate of recanalization achieved with stent-retrievers compared with other recanalization treatments, the use of these devices cannot clearly demonstrate better outcomes. Thus, futile recanalization occurs when successful recanalization fails to improve functional outcome. Recently, three RCTs, namely synthesis, IMS-III, and MR-rescue, have not been demonstrated any clear benefit for endovascular treatment. Most likely, these trials were not adequately designed to prove the superiority of endovascular treatment because they did not use optimal target populations, vascular status was not evaluated in all patients, relatively high rates of patients did not have enough mismatch, time from baseline neuroimaging to recanalization were too long or the devices used are now obsolete relative to stent-retrievers. Several RCTs currently underway are trying to determine whether bridging therapy is more effective than intravenous treatment and if mechanical thrombectomy is more effective than best medical treatment in patients ineligible for intravenous thrombolysis.

Reperfusion therapies for acute ischemic stroke: an update

Acute ischemic stroke is a major cause of morbidity and mortality in developed countries. Intravenous thrombolysis with tissue plasminogen activator (tPA) within 4.5 hours of symptoms onset significantly improves clinical outcomes in patients with acute ischemic stroke. This narrow window for treatment leads to a small proportion of eligible patients to be treated. Intravenous or intra-arterial trials, combined intravenous/intra-arterial trials, and newer devices to mechanically remove the clot from intracranial arteries have been investigated or are currently being explored to increase patient eligibility and to improve arterial recanalization and clinical outcome. New retrievable stent-based devices offer higher revascularization rates with shorter time to recanalization and are now generally preferred to first generation thrombectomy devices such as Merci Retriever or Penumbra System. These devices have been shown to be effective for opening up occluded vessels in the brain but its efficacy for improving outcomes in patients with acute stroke has not yet been demonstrated in a randomized clinical trial. We summarize the results of the major systemic thrombolytic trials and the latest trials employing different endovascular approaches to ischemic stroke.

Endovascular stroke therapy

BACKGROUND

Following the development of intravenous thrombolysis as a successful treatment for ischaemic stroke, advances in neurointerventional radiology have facilitated endovascular approaches to treatment. This article reviews the available endovascular therapeutic options and their evidence-base.

SUMMARY

Initial studies demonstrated that endovascular treatment of ischaemic stroke with intra-arterial thrombolysis and/or the use of clot-retrieval, thrombus aspiration and stent-retriever devices produced early recanalisation and reperfusion and improved neurological outcome. More recent randomised trials, however, have failed to show translation of recanalisation into successful clinical outcome with 'time to treatment' proving crucial. In this rapidly evolving field, combined therapy incorporating intravenous and intra-arterial thrombolysis in combination with endovascular clot-retrieval has been developed and further studies are expected to yield better evidence to guide the optimal treatment of acute cerebral ischaemia.

Early Postmarket Experience After US Food and Drug Administration Approval With the Trevo Device for Thrombectomy for Acute Ischemic Stroke

BACKGROUND:

TREVO 2 showed the Trevo stent retriever to be more successful for revascularization than Merci for acute stroke intervention in patients treated within 8 hours of symptom onset. These results led to US Food and Drug Administration approval of Trevo.

OBJECTIVE:

To report the first postmarket experience with Trevo since US Food and Drug Administration approval at a single high-volume comprehensive stroke center in the United States.

METHODS:

A retrospective analysis of prospectively collected data was conducted in patients who underwent intervention for ischemic stroke with the Trevo device. Trevo was used alone or in conjunction with other intra-arterial devices. Two groups of patients were identified: those with symptom onset within (group 1) and those with symptom onset beyond (group 2) 8 hours. Recanalization, outcome, symptomatic intracranial hemorrhage, and in-hospital and 90-day mortality were assessed.

RESULTS:

Fifty-two patients were identified, 27 in group 1 and 25 in group 2. Thrombolysis in Cerebral Infarction grade 2 to 3 revascularization was achieved in 93% of group 1 and 84% of group 2 patients. In-hospital mortality and symptomatic intracranial hemorrhage rates were 3.8% and 12% for groups 1 and 2, respectively. Ninety-day mortality was 15% and 24% for groups 1 and 2, respectively. In groups 1 and 2, 48% and 42% of patients, respectively, had good outcomes (modified Rankin Scale score, 0–2), and 50% in both groups of patients achieved Thrombolysis in Cerebral Infarction grade 3 revascularization. Group 2 had longer revascularization times and required adjuvant devices more frequently.

CONCLUSION:

Our postmarket experience shows that in highly selected patients Trevo is safe and effective, even beyond 8 hours, despite longer procedure times and the need for adjuvant devices.

Outcomes of a contemporary cohort of 536 consecutive patients with acute ischemic stroke treated with endovascular therapy

BACKGROUND AND PURPOSE

We sought to assess outcomes after endovascular treatment/therapy of acute ischemic stroke, overall and by subgroups, and looked for predictors of outcome.

METHODS

We used data from a mandatory, population-based registry that includes external monitoring of completeness, which assesses reperfusion therapies for consecutive patients with acute ischemic stroke since 2011. We described outcomes overall and by subgroups (age ≤ or >80 years; onset-to-groin puncture ≤ or >6 hours; anterior or posterior strokes; previous IV recombinant tissue-type plasminogen activator or isolated endovascular treatment/therapy; revascularization or no revascularization), and determined independent predictors of good outcome (modified Rankin Scale score ≤2) and mortality at 3 months by multivariate modeling.

RESULTS

We analyzed 536 patients, of whom 285 received previous IV recombinant tissue-type plasminogen activator. Overall, revascularization (modified Thrombolysis In Cerebral Infarction scores, 2b and 3) occurred in 73.9%, 5.6% developed symptomatic intracerebral hemorrhages, 43.3% achieved good functional outcome, and 22.2% were dead at 90 days. Adjusted comparisons by subgroups systematically favored revascularization (lower proportion of symptomatic intracerebral hemorrhages and death rates and higher proportion of good outcome). Multivariate analyses confirmed the independent protective effect of revascularization. Additionally, age >80 years, stroke severity, hypertension (deleterious), atrial fibrillation, and onset-to-groin puncture ≤6 hours (protective) also predicted good outcome, whereas lack of previous disability and anterior circulation strokes (protective) as well as and hypertension (deleterious) independently predicted mortality.

CONCLUSIONS

This study reinforces the role of revascularization and time to treatment to achieve enhanced functional outcomes and identifies other clinical features that independently predict good/fatal outcome after endovascular treatment/therapy.

Endovascular treatment of tandem vascular occlusions in acute ischemic stroke

BACKGROUND AND PURPOSE

Tandem vascular occlusions are an important cause of acute ischemic stroke (AIS) and present unique treatment challenges. We report our experience of managing a subset of AIS patients with extracranial vascular stenting/angioplasty and intracranial revascularization.

METHODS

Consecutive patients who presented at three centers with AIS from tandem vascular occlusions confirmed by brain and neck CT imaging were included in the study. We retrospectively analyzed the patient demographics, National Institute of Health Stroke Scale (NIHSS) score and modified Rankin Scale (mRS) score at the time of admission, treatment strategy, angiographic results using the Thrombolysis In Cerebral Infarction (TICI) score, and clinical and imaging follow-up.

RESULTS

Twenty-eight patients were included. The mean NIHSS score at admission was 18. Extracranial carotid occlusions with a concomitant middle cerebral artery occlusion were seen in 89.3% of patients (n=25) and vertebral artery combined with basilar artery lesions in 10.7% (n=3). An antegrade approach (ie, treatment of the extracranial lesion first) was used in 24 patients (85.7%). Proximal occlusion recanalization was achieved usually with a stent (n=27; 96.4%). Pursuant to intracranial revascularization techniques, ≥ TICI 2A recanalization was seen in 96.4% of patients. An mRS score of ≤ 2 at 90 days was achieved in 56.5% of patients.

CONCLUSIONS

Our study shows preliminary data from three centers on recanalization of tandem occlusions in patients presenting with AIS. There was a preference to revascularize the proximal occlusion using a stent followed by distal recanalization with mechanical thrombectomy, intra-arterial thrombolysis or a combination of these. This approach has low periprocedural complications and can achieve an excellent angiographic and clinical outcome.

Comparative efficacy of different acute reperfusion therapies for acute ischemic stroke: a comprehensive benefit-risk analysis of clinical trials

BACKGROUND

Numerous acute reperfusion therapies (RPT) are currently investigated as potential new therapeutic targets in acute ischemic stroke (AIS). We conducted a comprehensive benefit-risk analysis of available clinical studies assessing different acute RPT, and investigated the utility of each intervention in comparison to standard intravenous thrombolysis (IVT) and in relation to the onset-to-treatment time (OTT).

METHODS

A comprehensive literature search was conducted to identify all available published, peer-reviewed clinical studies that evaluated the efficacy of different RPT in AIS. Benefit-to-risk ratio (BRR), adjusted for baseline stroke severity, was estimated as the percentage of patients achieving favorable functional outcome (BRR1, mRS score: 0-1) or functional independence (BRR2, mRS score: 0-2) at 3 months divided by the percentage of patients who died during the same period.

RESULTS

A total of 18 randomized (n = 13) and nonrandomized (n = 5) clinical studies fulfilled our inclusion criteria. IV therapy with tenecteplase (TNK) was found to have the highest BRRs (BRR1 = 5.76 and BRR2 = 6.82 for low-dose TNK; BRR1 = 5.80 and BRR2 = 6.87 for high-dose TNK), followed by sonothrombolysis (BRR1 = 2.75 and BRR2 = 3.38), while endovascular thrombectomy with MERCI retriever was found to have the lowest BRRs (BRR1 range, 0.31-0.65; BRR2 range, 0.52-1.18). A second degree negative polynomial correlation was detected between favorable functional outcome and OTT (R (2) value: 0.6419; P < 0.00001) indicating the time dependency of clinical efficacy of all reperfusion therapies.

CONCLUSION

Intravenous thrombolysis (IVT) with TNK and sonothrombolysis have the higher BRR among investigational reperfusion therapies. The combination of sonothrombolysis with IV administration of TNK appears a potentially promising therapeutic option deserving further investigation.

Endovascular therapy in hyperacute ischaemic stroke: history and current status

This is a literature review on to the use of endovascular therapy in hyperacute ischaemic stroke secondary to large vessel occlusion (LVO). The prognosis for LVO is generally poor and the efficacy of intravenous tissue plasminogen activator (IV TPA) in the treatment of this subtype of stroke is questionable. It is well documented that recanalisation is associated with improved outcomes but IV TPA has limited efficacy in LVO recanalisation and the complication rates are higher for IV TPA in this stroke subset. Improved recanalisation rates have been demonstrated with intra-arterial TPA and first and second generation mechanical techniques but the rate of favourable outcome has not overtly mirrored this improvement. Several controversial trials using these early techniques have recently been published but fail to reflect modern practice which centres on the use of stent-retriever technology. This has been proven to be superior to older techniques. Not only are recanalisation rates higher, but the speed of recanalisation is greater and clinical results are improved. Multiple observational studies demonstrate consistently high rates of LVO recanalisation; TICI 2b/3 in the order of 65-95% and, rates of favourable outcome (mRS 0-2) in the order of 55% (42.5-77%) in clinically moderate to severe stroke with complicating symptomatic haemorrhage in the order of 1.5-15%. A major factor determining outcome is time to treatment but success has been demonstrated using these devices with bridging therapy, after IV TPA failure or as a stand-alone treatment.

Thrombectomy in patients with large cerebral artery occlusion: a single-center experience with a new stent retriever

INTRODUCTION

The Trevo device, a new stent retriever, may be utilized in patients with large cerebral artery occlusion.

METHODS

Fifty patients with large cerebral artery occlusion and treated with the Trevo device were analyzed. Patients may have received intravenous thrombolysis as a bridging concept in addition to thrombectomy. Outcome and recanalization parameters were documented using the National Institutes of Health Scale, the modified Ranking Scale (mRS) and Thrombolysis in Cerebral Infarction (TICI) score.

RESULTS

In all, 82% (95% confidence interval [CI]: 69%-91%) were documented with TICI 2b and 3. Good clinical outcome after 90 days (mRS ≤ 2) was assessed in 61% (95% CI: 46%-75%). Symptomatic intracerebral hemorrhage occurred in 6 patients (12%, 95% CI: 1%-17%). The overall mortality rate was 14% (95% CI: 6%-27%).

CONCLUSION

Thrombectomy with the new stent retriever device is feasible and effective and has an acceptable risk of intra-cerebral hemorrhage even in combination with pharmacological revascularization techniques.

REVASCAT: a randomized trial of revascularization with SOLITAIRE FR device vs. best medical therapy in the treatment of acute stroke due to anterior circulation large vessel occlusion presenting within eight-hours of symptom onset

REVASCAT is a prospective, multicenter, randomized trial seeking to establish whether subjects meeting following main inclusion criteria: age 18-80, baseline National Institutes of Health Stroke Scale ≥6, evidence of intracranial internal carotid artery or proximal (M1 segment) middle cerebral artery occlusion, Alberta Stroke Program Early Computed Tomography score of >7 on non-contrast CT or >6 on diffusion-weighted magnetic resonance imaging , ineligible for or with persistent occlusion after intravenous alteplase and procedure start within 8 hours from symptom onset, have higher rates of favorable outcome when treated with the Solitaire FR embolectomy device compared to standard medical therapy alone The primary end-point, based on intention-to-treat criteria is the distribution of modified Rankin Scale scores at 90 days. Projected sample size is 690 patients. Estimated common odds ratio is 1●615. Randomization is performed under a minimization process using age, baseline NIHSS, therapeutic window, occlusion location and investigational center. The study follows a sequential analysis (triangular model) with the first approach to test efficacy at 174 patients and subsequent analyses (if necessary) at 346, 518, and 690 subjects. Secondary end-points are infarct volume evaluated on CT at 24 h, dramatic early favorable response, defined as NIHSS of 0-2 or NIHSS improvement ≥8 points at 24 h and successful recanalization in the Solitaire arm according to the thrombolysis in cerebral infarction (TICI) classification defined as TICI 2b or 3. Safety variables are mortality at 90 days, symptomatic intracranial haemorrhage rates at 24 hours and procedure related complications.

Stent retrievers in acute ischemic stroke: complications and failures during the perioperative period

BACKGROUND AND PURPOSE

Stent retriever-assisted thrombectomy promotes high recanalization rates in acute ischemic stroke. Nevertheless, complications and failures occur in more than 10% of procedures; hence, there is a need for further investigation.

MATERIALS AND METHODS

A total of 144 patients with ischemic stroke presenting with large-vessel occlusion were prospectively included. Patients were treated with stent retriever-assisted thrombectomy ± IV fibrinolysis. Baseline clinical and imaging characteristics were incorporated in univariate and multivariate analyses. Predictors of recanalization failure (TICI 0, 1, 2a), and of embolic and hemorrhagic complications were reported. The relationship between complication occurrence and periprocedural mortality rate was studied.

RESULTS

Median age was 69.5 years, and median NIHSS score was 18 at presentation. Fifty patients (34.7%) received stand-alone thrombectomy, and 94 (65.3%) received combined therapy. The procedural failure rate was 13.9%. Embolic complications were recorded in 12.5% and symptomatic intracranial hemorrhage in 7.6%. The overall rate of failure, complications, and/or death was 39.6%. The perioperative mortality rate was 18.4% in the overall cohort but was higher in cases of failure (45%; P = .003), embolic complications (38.9%; P = .0176), symptomatic intracranial hemorrhages (45.5%; P = .0236), and intracranial stenosis (50%; P = .0176). Concomitant fibrinolytic therapy did not influence the rate of recanalization or embolic complication, or the intracranial hemorrhage rate. Age was the only significant predictive factor of intracranial hemorrhage (P = .043).

CONCLUSIONS

The rate of perioperative mortality was significantly increased in cases of embolic and hemorrhagic complications, as well as in cases of failure and underlying intracranial stenoses. Adjunctive fibrinolytic therapy did not improve the recanalization rate or collateral embolic complication rate. The rate of symptomatic intracranial hemorrhage was not increased in cases of combined treatment.

Neurothrombectomy in the treatment of acute ischaemic stroke

Major ischaemic stroke is a leading cause of morbidity and mortality in industrialized countries. For patients with acute stroke, fast and effective vessel recanalization is important for successful treatment. Neurothrombectomy--that is, angiographically performed mechanical thrombus removal from intracranial arteries--results in higher recanalization rates than with pharmaceutical thrombolysis alone, but the value of this treatment in terms of clinical outcome remains to be established. This article summarizes the history of intra-arterial stroke treatment, outlines the recent developments and the different techniques used, and discusses the results of current studies on neurothrombectomy. Owing to the high morphological and clinical variability of stroke, careful patient selection in future randomized controlled trials will be crucial for assessment of the true potential of neurothrombectomy.

Neurothrombectomy for the treatment of acute ischemic stroke: results from the TREVO study

BACKGROUND

Fast recanalization has been shown to be one of the most important factors for good clinical outcome in stroke patients with acute large vessel occlusion. While intravenous thrombolysis has been shown to be of limited effect in patients with large clot burden, intra-arterial neurothrombectomy offers a new and promising possibility to achieve high recanalization rates within a short time. The Trevo device is a stent-like retriever and was primarily designed to remove thrombus in patients experiencing an acute ischemic stroke. We report on the results of the TREVO Study, which was a prospective, multicenter study in acute stroke patients treated with the Trevo device.

METHODS

Patients were recruited in seven European centers under the control of an external monitor. Centers were selected because of their long experience with interventional stroke therapy especially with neurothrombectomy. We included adults aged 18-85 years with angiographically confirmed large vessel occlusion strokes and NIHSS scores of 8-30 and treatable within 8 h of symptom onset. The primary endpoint was revascularization, defined as at least TICI (thrombolysis in cerebral infarction) 2a. The revascularization scores were assessed by an independent core lab. Secondary endpoints were clinical outcome at 90 days (mRS 90), any device-related serious adverse events and the rate of symptomatic intracerebral hemorrhages.

RESULTS

60 patients were enrolled. The overall recanalization rate (≥TICI 2a) was 91.7% and TICI 2b and 3 was achieved in 78.3%. At 90 days, 55% of the patients had a favorable neurological outcome (mRS 0-2) and 20% had died. Patients with successful recanalization (TICI 2a,b/3) had a good 90-day neurological outcome (mRS 0-2) in 60%, whereas no patient without recanalization had a mRS 90 <3. The overall rate of symptomatic intracerebral hemorrhage according to the SITS-MOST criteria was 5% (3/60).

CONCLUSIONS

The study suggest that the Trevo Stentriever™ is a safe and effective device, which may offer the possibility of a high reperfusion rate and a high rate of patients with good clinical outcome after acute ischemic stroke due to proximal arterial occlusion. Randomized trials comparing intravenous thrombolysis with neurothrombectomy are now urgently needed to evaluate this new approach of interventional stroke therapy.

[Mechanical recanalization in acute stroke. Torture or choice]

CLINICAL/METHODICAL ISSUE

Stroke is the third most common cause of death in the developed world and the leading cause of disability worldwide. The present demographic development will lead to increased numbers of stroke patients in the future.

STANDARD RADIOLOGICAL METHODS

Patient selection takes place by using various computer tomographic (CT) or magnetic resonance (MR) imaging modalities. For endovascular stroke treatment a modern biplane angiography suite is recommended.

METHODICAL INNOVATIONS

Intra-arterial chemical thrombolysis was shown to be effective in achieving recanalization and improving clinical outcome. Mechanical devices were introduced in the late 1990s and the highly effective stent retriever was recently included.

PERFORMANCE

Mechanical devices allows a recanalization rate of up to 90 % of affected brain vessels.

ACHIEVEMENTS

The advantage of a stent retriever compared to other mechanical devices seems to be an improvement in good clinical outcome.

PRACTICAL RECOMMENDATIONS

Currently, the stent retriever seems to be the definitive first choice in the use of mechanical devices for intra-arterial recanalization treatment in acute ischemic stroke.

Retrievable stent thrombectomy in the treatment of acute ischemic stroke: analysis of a revolutionizing treatment technique

Acute ischemic stroke resulting from intracranial vessel occlusion is associated with high morbidity and mortality. The mainstays of therapy are fibrinolytics and mechanical thrombectomy in properly selected patients. A new Food and Drug Administration-approved technology to perform thrombectomy, retrievable stenting, may provide superior revascularization rates and improved patient outcomes. We analyzed the cumulative human experience reported for the Trevo Pro Retrieval System (Stryker, Kalamazoo, MI, USA) and the Solitaire FR Revascularization Device (ev3, Irvine, CA, USA) as the definitive treatment for acute ischemic stroke. A literature search was undertaken to identify studies using the retrievable stents published up to September 2012. Nineteen studies identified a total of 576 patients treated with either the Trevo (n=221) or Solitaire (n=355) devices. Pooled data analysis identified median baseline National Institutes of Health Stroke Scale scores of 18.5 ± 0.289 (standard error of the mean) and 17.9 ± 0.610, and time to recanalization of 53.9 ± 23.6 minutes and 59.0 ± 8.0 minutes for the Trevo and Solitaire groups, respectively. Recanalization was variably defined by individual studies, most commonly achieving at least a thrombolysis in cerebral infarction score of 2a-3 or a thrombolysis in myocardial infarction score of 2-3. Revascularization (83%, 82%), mortality (31%, 14%), hemorrhage (8%, 6%), device complications (5%, 6%), and good patient outcomes (51%, 47%) were found with the Trevo and Solitaire devices, respectively. Preliminary analysis reveals excellent clinical outcomes for retrievable stent technology. This may be attributable to both high rates of revascularization with a relatively short time to perfusion restoration.

Mechanical thrombectomy with the penumbra 3D separator and lesional aspiration: technical feasibility and clinical outcome

BACKGROUND AND PURPOSE

Intravenous recombinant human tissue plasminogen activator (IV rtPA) therapy has limited revascularization rates in large artery occlusions. We describe the safety and effectiveness of the self-expanding, fully retrievable Separator 3D device as a component of the Penumbra System in revascularization of large artery occlusion in acute ischemic stroke. The 3D secures thrombus with lesional aspiration and functions by retrieving or debulking the clot.

MATERIALS AND METHODS

Prospective, single-center pilot study of 20 patients with an acute ischemic stroke secondary to a large artery occlusion within 9 h from symptom onset. The occlusion sites were middle cerebral artery in nine patients, internal carotid artery terminus in eight patients, and basilar artery in three patients. Thrombectomy was performed in 18 patients who had previously received IV rtPA, and of these, two patients had prior failed treatment with the Solitaire stent. One patient had prior failed treatment with the Revive stent.

RESULTS

Successful revascularization defined by Thrombolysis in Cerebral Infarction grade 2b-3 was achieved in 17 of 20 (85%) treated vessels. The median time from symptom onset to recanalization was 4.4 h (interquartile range 3.8-5.6 h). No procedural complications occurred, and no symptomatic intracranial hemorrhage was observed. Three (15%) patients died. At 90 days, 50% of patients showed good functional outcome (modified Rankin Scale score ≤ 2).

CONCLUSION

Early results suggest that the Separator 3D, which combines a retriever with lesional aspiration, enables safe and effective revascularization.

Selecting endovascular treatment strategy according to the location of intracranial occlusion in acute stroke

BACKGROUND

Selection of endovascular approaches for acute stroke patients remains unclear. The efficacy of intra-arterial therapy (IAT) has been demonstrated in the past. However, in the last years, the use of mechanical thrombectomy by retrievers (RET) is increasing at the expense of IAT. We aimed to compare several clinical outcomes between patients treated with IAT or RET.

METHODS

In a 6-year period, acute stroke patients (<8 h) with confirmed internal carotid artery (ICA) occlusion or middle cerebral artery (MCA) occlusion undergoing endovascular therapy were prospectively included in our database. Patients who underwent intra-arterial tissue plasminogen activator (tPA) ± microguidewire mechanical clot disruption (IAT group) were compared with those who underwent thrombectomy with the Solitaire® or Trevo® retrievers (RET group). Recanalization (REC) was considered if at the end of the endovascular procedure thrombolysis in cerebral infarction score was 2a-3. Dramatic clinical improvement (DCI) was defined as a decrease of ≥10 NIHSSS points from baseline to discharge or 7 days.

RESULTS

One hundred and eighty patients were included, 100 (55.6%) patients in the IAT group and 80 patients (44.4%) in the RET group. There were no differences in baseline characteristics (age, gender, risk factors profile, previous treatment with i.v. tPA, baseline NIHSS, extracranial ICA angioplasty and time to REC). Rates of REC, DCI and symptomatic intracranial hemorrhage were also similar between groups. Among patients with ICA occlusions (41 IAT, 34 RET), REC was significantly higher with RET (83.9 vs. 61%; p = 0.04).There was a trend towards a higher DCI rate in the RET group (32.3%) compared with the IAT group (14.6%; p = 0.06). According to MCA occlusions, there were no major differences in the main outcome variables. The number needed to treat to achieve one additional DCI with RET compared with IAT was 12 for MCA occlusions, and only 5 for ICA occlusions.

CONCLUSIONS

Among acute stroke patients undergoing endovascular therapies, the benefits of RET over IAT are greater in ICA occlusions. Retrievers may be considered as the first therapeutic option in these patients.

What is meant by "TICI"?

BACKGROUND

In 2003, Higashida et al proposed the Thrombolysis In Cerebral Infarction scale to evaluate angiographic intracranial flow. Our aim is to review how subsequently published studies define TICI.

MATERIALS AND METHODS

We used the ISI Web of Knowledge and SciVerse Scopus databases to search for "TICI" and "thrombolysis in cerebral infarction" and for articles that cited the original TICI paper from January 2004 through May 2012. Articles were categorized according to their definition of the TICI categories, typically grades 0-4, with grade 2 (partial reperfusion) subdivided into 2a and 2b, and rate of contrast entry to the perfused area. In addition, we catalogued the type of redefinitions of TICI subcategory 2 and additions of new categories.

RESULTS

Of 236 articles screened, 74 were included. Eight (11%) explicitly followed the TICI scale as originally defined. Thirty-seven (50%) cited Higashida but did not define their scale. Fifteen (21%) used and explained modified scales. Thirteen (18%) used the term TICI, but did not define the scale and did not cite Higashida. Eighteen (24%) specified a 2a subcategory. Nine defined grade 2a as <67% filling, 6 defined it as <50%, and 3 did not offer a percentage. Two studies added a 2c subcategory. Fifty-two (70%) used a cutoff level to define "successful reperfusion." Of these, 65% used TICI ≥2, 33% used TICI ≥2b, and 2% used TICI = 3.

CONCLUSIONS

There is substantial variability in the definition and/or application of the TICI scale in the literature. This variability could considerably impact our understanding of results of revascularization studies.