Solitaire FR thrombectomy system: immediate results in 56 consecutive acute ischemic stroke patients

The impact of SAH finding on CT to the clinical outcome after mechanical thrombectomy for large vessel occlusion

BACKGROUND AND PURPOSE

Whether subarachnoid haemorrhage (SAH) after mechanical thrombectomy affects the clinical outcomes of patients with acute large-vessel occlusion remains unclear. This study aimed to investigate the clinical impact of SAH on computed tomography (CT) after mechanical thrombectomy.

METHODS

The SKIP study was an investigator-initiated, multicentre, randomised, open-label clinical trial. This study was performed in 23 hospital networks in Japan from January 1, 2017, to July 31, 2019. Among the 204 patients, seven were excluded because they did not undergo mechanical thrombectomy (MT) and had a modified Rankin scale (mRS) score > 2. The main outcome was the association between SAH within 36 h after mechanical thrombectomy and the clinical outcome at 90 days.

RESULTS

Among 197 patients, the median age was 74 (67-79) years, 62.9% were male. Moreover, 26 (13.2%) patients had SAH (seven isolated SAH) on CT within 36 h. The SAH rate did not differ according to IV rt-PA administration (p = 0.4). The rate of favourable clinical outcomes tended to be lower in patients with SAH rather than patients without SAH (11 [42%] vs. 106 [62%], p = 0.08). Among the seven patients with isolated SAH, 6 showed favourable outcomes at 90 days. In the multivariate regression analysis, the presence of SAH within 36 h from onset was not associated with clinical outcome (Odd ratio, 0.59; 95% confidence interval, 0.18-1.95; p = 0.38).

CONCLUSIONS

Among patients with acute stroke treated with MT, SAH, especially isolated SAH findings on CT, were not associated with poor clinical outcomes after 90 days.

TRIAL REGISTRATION NUMBER

UMIN000021488.

Recommendations for finite element modelling of nickel-titanium stents-Verification and validation activities

The objective of this study is to present a credibility assessment of finite element modelling of self-expanding nickel-titanium (Ni-Ti) stents through verification and validation (VV) activities, as set out in the ASME VV-40 standard. As part of the study, the role of calculation verification, model input sensitivity, and model validation is examined across three different application contexts (radial compression, stent deployment in a vessel, fatigue estimation). A commercially available self-expanding Ni-Ti stent was modelled, and calculation verification activities addressed the effects of mesh density, element integration and stable time increment on different quantities of interests, for each context of use considered. Sensitivity analysis of the geometrical and material input parameters and validation of deployment configuration with in vitro comparators were investigated. Results showed similar trends for global and local outputs across the contexts of use in response to the selection of discretization parameters, although with varying sensitivities. Mesh discretisation showed substantial variability for less than 4 × 4 element density across the strut cross-section in radial compression and deployment cases, while a finer grid was deemed necessary in fatigue estimation for reliable predictions of strain/stress. Element formulation also led to substantial variation depending on the chosen integration options. Furthermore, for explicit analyses, model results were highly sensitive to the chosen target time increment (e.g., mass scaling parameters), irrespective of whether quasistatic conditions were ensured (ratios of kinetic and internal energies below 5%). The higher variability was found for fatigue life simulation, with the estimation of fatigue safety factor varying up to an order of magnitude depending on the selection of discretization parameters. Model input sensitivity analysis highlighted that the predictions of outputs such as radial force and stresses showed relatively low sensitivity to Ni-Ti material parameters, which suggests that the calibration approaches used in the literature to date appear reasonable, but a higher sensitivity to stent geometry, namely strut thickness and width, was found. In contrast, the prediction of vessel diameter following deployment was least sensitive to numerical parameters, and its validation with in vitro comparators offered a simple and accurate (error ~ 1-2%) method when predicting diameter gain, and lumen area, provided that the material of the vessel is appropriately characterized and modelled.

Characterization of Subarachnoid Hyperdensities After Thrombectomy for Acute Stroke Using Dual-Energy CT

BACKGROUND AND OBJECTIVES

The presence of post-interventional subarachnoid hyperdensities (SA-HD) is a relatively common finding after mechanical thrombectomy (MT). We aimed to assess the incidence, characteristics, clinical relevance and predictors of SA-HD after MT as categorized through the use of post-interventional Dual Energy-CT (DE-CT).

METHODS

A single-center consecutive series of acute stroke patients treated with MT were retrospectively reviewed. Post-treatment SA-HD were defined as incident extra-axial hyperdensities in a follow-up DE-CT performed within a median of 8 hours after MT. SA-HD were further classified according to their content (isolated contrast extravasation versus blood extravasation) and extension [diffuse (hyperdensities in more than one extraparenchymal compartments) versus non-diffuse]. Adjusted logistic regression models assessed the association of SA-HD with pretreatment and procedural variables and with bad clinical outcome (shift towards worse categories in the ordinal Rankin Scale at 90 days).

RESULTS

SA-HD were observed in 120 (28%) of the 424 included patients (isolated contrast extravasation n=22, blood extravasation n=98). In this group, SA-HD were diffuse in 72 (60%) patients (isolated contrast extravasation n=7, blood extravasation n=65) and non-diffuse in 48 (40%) patients (isolated contrast extravasation n=15, blood extravasation n=33). Diffuse SA-HD were significantly associated with worse clinical outcome in adjusted models (cOR=2.3, 95%CI=1.36-4.00, p=0.002), unlike the specific SA-HD content alone. In contrast with the absence of SA-HD, only the diffuse pattern with blood extravasation was significantly associated with worse clinical outcome (cOR=2.4, 95%CI=1.36-4.15, p=0.002). Diffuse SA-HD patterns were predicted by M2 occlusions, more thrombectomy passes and concurrent parenchymal hematomas.

DISCUSSION

In our cohort of patients imaged within a median of 8 hours after MT, post-interventional SA-HD showed a diffuse pattern in 17% of thrombectomies and were associated with more arduous procedures. Diffuse SA-HD but not local collections of blood or contrast extravasations were associated with an increased risk of poor outcome and death. These findings reinforce the need for improvement in reperfusion strategies.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that in individuals with proximal carotid artery territory occlusions treated with mechanical thrombectomy, diffuse post-interventional subarachnoid hyperdensities on imaging 8 hours post-procedure are associated with worse clinical outcomes at 90 days.

Comparison of the Solitaire and Trevo Stents for Endovascular Treatment of Acute Ischemic Stroke: A Single.Center Experience

Aims

Limited studies have compared the effectiveness of Solitaire and Trevo stentrievers for endovascular thrombectomy to achieve recanalization and improve functional outcomes of patients with acute ischemic stroke. Therefore, we compared the safety and efficacy of the two stents during endovascular thrombectomy for patients with acute ischemic stroke.

Materials and Methods

This study included 130 patients who underwent endovascular thrombectomy using either the Trevo (n = 51) or the Solitaire (n = 79) stent for anterior circulation acute ischemic stroke. Recanalization was classified using thrombolysis in cerebral infarction (TICI) grading. Efficacy and safety of the devices during endovascular thrombectomy were analyzed by evaluating the rate of good recanalization after the first pass, clot retrieval rate, final recanalization grade, use of rescue treatment, recanalization time, and hemorrhagic and thromboembolic complications.

Results

Overall, good recanalization (TICI grades 2b and 3) was achieved (Solitaire: n = 57, 72.2%; Trevo: n = 46, 90.2%) (P = 0.01). The rate of good recanalization after the first pass and clot retrieval rate were similar between groups; however, the use of rescue treatment was more frequent in the Solitaire group. Recanalization time was shorter in the Trevo group. The good clinical outcome rate was higher in the Trevo group but not statistically significantly. The rates of symptomatic hemorrhage and thromboembolism were not significantly different between groups.

Conclusion

The Trevo stent achieved more successful recanalization with less need for rescue treatment and less time for recanalization than the Solitaire stent. There was no statistically significant difference in the clinical outcomes.

Subarachnoid Hemorrhage in Mechanical Thrombectomy for Acute Ischemic Stroke: Analysis of the STRATIS Registry, Systematic Review, and Meta-Analysis

Background: The indications for mechanical thrombectomy in acute ischemic stroke continue to broaden, leading neurointerventionalists to treat vessel occlusions at increasingly distal locations farther in time from stroke onset. Accessing these smaller vessels raises the concern of iatrogenic subarachnoid hemorrhage (SAH) owing to increasing complexity in device navigation and retrieval. This study aims to determine the prevalence of SAH following mechanical thrombectomy, associated predictors, and resulting functional outcomes using a multicenter registry and compare this with a systematic review and meta-analysis of the literature. Methods: Data from STRATIS (The Systematic Evaluation of Patients Treated with Neurothrombectomy Devices for Acute Ischemic Stroke) registry were analyzed dichotomized by the presence or absence of SAH after thrombectomy. Only patients with 24-h post-procedural neuroimaging were included (n = 841). Multivariable logistic regression was performed to identify significant predictors of SAH. A systematic review and random-effects meta-analysis was also conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) protocol. Results: The prevalence of post-thrombectomy SAH was 5.23% in STRATIS with 15.9% (1.84% overall) experiencing neurological decline. Distal location of vessel occlusion (OR 3.41 [95% CI: 1.75-6.63], p < 0.001) and more than 3 device passes (OR 1.34 [95% CI: 1.09-1.64], p = 0.01) were associated with a higher probability of SAH in contrast to a reduction with administration of intravenous tissue plasminogen activator (tPA) (OR 0.48 [95% CI: 0.26-0.89], p = 0.02). There was a trend toward a higher discharge NIHSS (8.3 ± 8.7 vs. 5.3 ± 6.6, p = 0.07) with a significantly reduced proportion achieving functional independence at 90 days (modified Rankin Score 0-2: 32.5% vs. 57.8%, p = 0.002) in SAH patients. Pooled analysis of 10,126 patients from 6 randomized controlled trials and 64 observational studies demonstrated a prevalence of 5.85% [95% CI: 4.51-7.34%, I ²: 85.2%]. Only location of vessel occlusion was significant for increased odds of SAH at distal sites (OR 2.89 [95% CI: 1.14, 7.35]). Conclusions: Iatrogenic SAH related to mechanical thrombectomy is more common with treatment of distally-situated occlusions and multiple device passes. While low in overall prevalence, its effect is not benign with fewer patients reaching post-procedural functional independence, particularly if symptomatic.

Retained Solitaire FR device after mechanical thrombectomy: Case review and management strategies

Solitaire FR device is a Food and Drug Administration-approved device for mechanical thrombectomy. It has been tested in various clinical trials for its safety and efficacy. We report a case of inadvertent detachment of the Solitaire FR device at stent-stent wire interface while performing mechanical thrombectomy. We review a rare phenomenon of retained Solitaire FR stent retriever in situ and discuss technique of avoidance and its management.

North American Solitaire Stent Retriever Acute Stroke registry: post-marketing revascularization and clinical outcome results

Background

Limited post-marketing data exist on the use of the Solitaire FR device in clinical practice. The North American Solitaire Stent Retriever Acute Stroke (NASA) registry aimed to assess the real world performance of the Solitaire FR device in contrast with the results from the SWIFT (Solitaire with the Intention for Thrombectomy) and TREVO 2 (Trevo versus Merci retrievers for thrombectomy revascularization of large vessel occlusions in acute ischemic stroke) trials.

Methods

The investigator initiated NASA registry recruited North American sites to submit retrospective angiographic and clinical outcome data on consecutive acute ischemic stroke (AIS) patients treated with the Solitaire FR between March 2012 and February 2013. The primary outcome was a Thrombolysis in Myocardial Ischemia (TIMI) score of ≥2 or a Treatment in Cerebral Infarction (TICI) score of ≥2a. Secondary outcomes were 90 day modified Rankin Scale (mRS) score, mortality, and symptomatic intracranial hemorrhage.

Results

354 patients underwent treatment for AIS using the Solitaire FR device in 24 centers. Mean time from onset to groin puncture was 363.4±239 min, mean fluoroscopy time was 32.9±25.7 min, and mean procedure time was 100.9±57.8 min. Recanalization outcome: TIMI ≥2 rate of 83.3% (315/354) and TICI ≥2a rate of 87.5% (310/354) compared with the operator reported TIMI ≥2 rate of 83% in SWIFT and TICI ≥2a rate of 85% in TREVO 2. Clinical outcome: 42% (132/315) of NASA patients demonstrated a 90 day mRS ≤2 compared with 37% (SWIFT) and 40% (TREVO 2). 90 day mortality was 30.2% (95/315) versus 17.2% (SWIFT) and 29% (TREVO 2).

Conclusions

The NASA registry demonstrated that the Solitaire FR device performance in clinical practice is comparable with the SWIFT and TREVO 2 trial results.

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.

Experimental evaluation of the NeVa™ thrombectomy device a novel stent retriever conceived to improve efficacy of organized clot removal

BACKGROUND AND PURPOSE

Stent retrievers are recognized as the most effective devices for intracranial thrombectomy. Although highly effective, such devices fail in clot removal when the brain vessel occlusion is due to organized, firm clots. The mechanism of failure is that during the retrieval, devices remain compressed by the organized clot and slide between it and the vessel wall without any removal effect. The aim of the current study is to present the preclinical evaluation of the Neva™ device, a novel stent retriever designed to improve the incorporation and removal of organized thrombi.

MATERIALS AND METHODS

Preclinical evaluation of the Neva™ device was divided in three main chapters: efficacy analysis, mechanical analysis and safety analysis. Efficacy and mechanical analysis aimed to investigate the behavior during the retrieval of the Neva™ device and its interaction with experimental organized clots. Safety analysis was conducted on animals in order to investigate the effect of the Neva™ device on real arteries after simulated thrombectomy maneuvers.

RESULTS

Neva™ device showed a high rate of "optimal clot integration" and "effective clot removal" which was related to constant cohesion to the vessel wall during retrievals. Safety analysis showed as the most frequent finding the disruption of the intima of the tested vessels with, in some cases, minimal disruption of the internal elastic lamina.

CONCLUSIONS

The Neva™ device has demonstrated safety and efficacy in a pre-clinical study. Such encouraging, preliminary results have to be compared with those of clinical trials.

Mechanical thrombectomy in acute ischaemic stroke: a review of the different techniques

Endovascular mechanical thrombectomy (MT) is reserved for acute ischaemic stroke secondary to large vessel occlusion. The various MT techniques employed in the treatment of hyperacute strokes are constantly evolving with new devices and improvisation of existing technology (Wahlgren, et al 2016). In this review, we describe a variety of MT techniques gained from our experience of performing over 350 procedures in 7 years of providing a 24/7 service within the national framework of a hyperacute stroke centre. We outline a number of endovascular techniques, procedure limitations, and potential complications.

Mechanical Thrombectomy with Solitaire Stent Retrieval for Acute Cardioembolic Stroke

Objective

Few studies have reported the outcome of mechanical thrombectomy with Solitaire stent retrival (MTSR) in subtypes of acute ischemic stroke. The purpose of this study was to evaluate the efficacy and result of MTSR in acute cardioembolic stroke.

Methods

Twenty consecutive patients with acute cardioembolic stroke were treated by MTSR. The angiographic outcome was assessed by thrombolysis in cerebral infarction (TICI) grade. TICI grade 2a, 2b, or 3 with a measurable thrombus that was retrieved was considered as a success when MTSR was performed in the site of primary vessel occlusion, and TICI grade 2b or 3 was considered as a success when final result was reported. Clinical and radiological results were compared between two groups divided on the basis of final results of MTSR. Persistent thrombus compression sign on angiogram was defined as a stenotic, tapered arterial lumen whenever temporary stenting was performed. The clinical outcomes were assessed by the modified Rankin Scale (mRS) at 3 months.

Results

The failure rate of MTSR was 20% (4/20) and other modalities, such as permanent stenting, were needed. Final successful recanalization (TICI grade 2b or 3) was 80% when other treatments were included. The rate of good outcome (mRS≤2) was 35% at the 3-month follow-up. Failure of MTSR was significantly correlated with persistent thrombus compression sign (p=0.001).

Conclusion

Some cases of cardioembolic stroke are resistant to MTSR and may need other treatment modalities. Careful interpretation of angiogram may be helpful to the decision.

Intra-Arterial Treatment for Patients with Severe Acute Vertebrobasilar Occlusion: A Single-Center Retrospective Study

BACKGROUND

Recently, favorable outcomes from several randomized controlled trials of rapid endovascular treatment for acute ischemic stroke has emerged.

OBJECTIVE

The aim of this retrospective study is to present our clinical experience in severe acute vertebrobasilar occlusion (AVBO) using intra-arterial treatment (IAT).

METHODS

Twenty patients with ischemic stroke in the vertebrobasilar circulation treated by IAT between March 2011 and December 2014 were included. We retrospectively assessed National Institutes of Health Stroke Scale (NIHSS) score on admission and at discharge, Thrombolysis in Cerebral Infarction (TICI) scale, and clinical outcome using modified Rankin scale (mRs) at 90 days, and causes of stroke were prospectively assessed.

RESULTS

The mean NIHSS score on admission was 26.4 ± 7.9 (range 9-33) points. The mean time from symptom onset to revascularization was 349.5 ± 124.0 (range 201-579) minutes. Successful recanalization (TICI ≥2b) was achieved in 19 (95.0%) patients. The mean NIHSS score at discharge was 5.7 ± 9.0 (range 0-30) points. A favorable clinical outcome (mRS ≤2) was observed in 12 (60.0%) patients at 90 days and mortality was 25.0% (n = 5).

CONCLUSION

IAT for AVBO provides high rate of recanalization, favorable clinical outcome, and improved survival.

Mechanical Recanalization for Acute Embolic Occlusion at the Origin of the Superior Mesenteric Artery

Purpose:

We report a combined technique consisting of thrombectomy and thromboaspiration for the treatment of acute embolic occlusion of the superior mesenteric artery (SMA) at the origin.

Case:

A 90-year-old female with chronic atrial fibrillation had a sudden onset of abdominal pain and hematochezia due to acute embolic occlusion at the origin of the SMA. Computed tomographic findings showed reversible bowel wall ischemia. We performed mechanical thrombectomy using the Solitaire FR revascularization device, a self-expanding and fully retrievable stent-based thrombectomy system for acute intracranial large artery occlusion, combined with manual aspiration through a 6F guiding sheath placed at the SMA origin via a right brachial approach. Prompt and complete recanalization of the SMA was obtained without distal embolism, and intestinal necrosis was avoided.

Conclusion:

Combined endovascular procedures of mechanical thrombectomy using the Solitaire FR with thromboaspiration may allow prompt recanalization, clot removal, and prevention of distal embolism and therefore would be a new therapy for acute embolic occlusion at the origin of the SMA.

Efficacy of Proximal Aspiration Thrombectomy for Using Balloon-Tipped Guide Catheter in Acute Intracranial Internal Carotid Artery Occlusion

Objective

Mechanical thrombectomy (MT) for acute intracranial internal carotid artery (ICA) occlusion is often complicated by difficult revascularization and non-involved territory embolization possibly related with larger clot-burden. This study aims to evaluate the efficacy of proximal aspiration thrombectomy (PAT) using a balloon-tipped guide catheter for clot-burden reduction in such cases with period-to-period analysis (period 1 : standard MT without PAT; period 2 : PAT first, then standard MT for the remaining occlusion).

Methods

Eighty-six patients who underwent MT for acute intracranial ICA occlusion were included in this analysis from the prospectively maintained stroke registry (33 patients in period 1 and 53 in period 2). In period 2, 'responder' was defined as a case where some amount of clot was retrieved by PAT and the following angiography showed partial or full recanalization.

Results

Fifteen of fifty-three patients in period 2 (28.3%) were 'responders' to PAT. There was a significantly higher incidence of atrial fibrillation in the 'responder' subgroup. Period 2 showed a significantly shorter puncture-to-reperfusion time (94.5 minutes vs. 56.0 minutes; p=0.002), a significantly higher Thrombolysis in Cerebral Infarction of 2b-3 reperfusion (45.5% vs. 73.6%; p=0.009), but only a trend for better 3-month favorable outcome (mRS 0–2; 36.4% vs. 54.7%; p=0.097). There was no increase in the incidence of procedure-related complications or intracranial hemorrhage in period 2.

Conclusion

A strategy of PAT before standard MT may result in shorter puncture-to-reperfusion time and better angiographic outcome than a strategy of standard MT for acute intracranial ICA occlusion.

The use of stent retrievers in acute ischemic stroke

INTRODUCTION

Acute ischemic stroke (AIS) is one of the leading causes of mortality and adult disability worldwide. For two decades, the preferred approach for AIS was intravenous recombinant tissue plasminogen activator (IV tPA). However, IV tPA cannot be given to many AIS patients who do not meet strict criteria for its use. IV tPA has also had lesser benefit in patients with large clot burden in the context of large vessel occlusion (LVO).

AREAS COVERED

Endovascular stroke therapy had been an 'unproven' therapy despite numerous trials of intra-arterial pharmacologic thrombolysis and mechanical thrombectomy. With the advent of stent-retriever devices, there has been a paradigm shift in the utilization of endovascular therapies for AIS. Our review discusses cerebrovascular hemodynamics, the basis of the recanalization models in AIS, aspects of intravenous thrombolysis, prior generations of endovascular therapy, and the recent successful AIS stent retriever trials. Expert commentary: Recently 'stent-retrievers', a new generation of mechanical thrombectomy devices, were shown to be associated with improved functional outcomes in AIS secondary to proximal intracranial anterior circulation LVO. Stent retrievers are a major advance in AIS care and will have significant impact on the evolution of stroke systems of care.

Rapid learning curve for Solitaire FR stent retriever therapy: evidence from roll-in and randomised patients in the SWIFT trial

BACKGROUND

In light of recent positive trial data for endovascular therapy in acute ischemic stroke (AIS), stent retriever use by practitioners without prior experience with these devices may become more common.

OBJECTIVE

To assess the safety and efficacy of thrombectomy for AIS using Solitaire for patients treated in the roll-in period of the Solitaire With the Intention For Thrombectomy (SWIFT) trial, which represented the first clinical use of the device for these interventionalists.

METHODS

Prospectively collected demographic, clinical, and angiographic data on patients treated in the initial roll-in and subsequent randomized phases of the SWIFT study were collected and analyzed. Key statistical analyses were validated by an independent external statistician.

RESULTS

Patients in the roll-in period achieved equivalently high rates of reperfusion (55%) compared with those treated with the device in the randomized phase (61%). Rates of adverse events were comparable (13% vs. 9%). Rates of good neurological outcome were equivalent between the roll-in and randomized patients treated with Solitaire (63% vs. 58%). Including the roll-in patients strengthened the conclusions of the study, that reperfusion rates without symptomatic hemorrhage with Solitaire were greater than with Merci (59% vs. 24%, p<0.001).

CONCLUSIONS

Thrombectomy in AIS using the Solitaire stent retriever device can be performed safely and effectively when used by experienced neurointerventionalists without previous experience with the device.

TRIAL REGISTRATION NUMBER

The SWIFT study is registered with ClinicalTrials.gov, number NCT 01054560.

Experimental evaluation of stent retrievers' mechanical properties and effectiveness

Background

Five randomized controlled trials recently appeared in the literature demonstrating that early mechanical thrombectomy in patients with acute ischemic stroke is significantly related to an improved outcome. Stent retrievers are accepted as the most effective devices for intracranial thrombectomy.

Objective

To analyze the mechanical properties of stent retrievers, their behavior during retrieval, and interaction with different clots and to identify device features that might correlate with the effectiveness of thrombus removal.

Materials and methods

All stent retrievers available in France up to June 2015 were evaluated by mechanical and functional tests aimed at investigating the variation of their radial force and their behavior during retrieval. Devices were also tested during in vitro thrombectomies using white and red experimental thrombi produced with human blood. Functional tests and in vitro thrombectomies were conducted using a rigid 3D printed vascular model.

Results

Mechanical tests showed a variation in radial force during retrieval for each stent. A constant radial force during retrieval was related to continuous cohesion over the vessel wall and a higher rate of clot removal efficacy. All stent retrievers failed when interacting with white large thrombi (diameter ≥6 mm).

Conclusions

None of the tested devices were effective in removing white clots of large diameter (≥6 mm). Constant radial force during retrieval allows constant cohesion to the vessel wall and pressure over the clot; such features allow for a higher rate of clot removal.

Mechanical thrombectomy by Solitaire stent for treating acute ischemic stroke: A prospective cohort study

BACKGROUND

Acute ischemic stroke (AIS) is a worldwide serious health problem. Intravenous (IV) thrombolysis with recombinant tissue plasminogen activator (rt-PA) is the standard treatment; however, only a small number of patients benefit from it due to the strict application restrictions. Recently, more and more evidence prove mechanical thrombectomy is an effective and safe therapy of AIS.

PATIENTS AND METHODS

From December 2010 to March 2015, 83 patients who underwent mechanical thrombectomy were collected as a sample pool. All patients met the following criteria: National Institutes of Health Stroke Scale (NIHSS) score ≥10, treatment performed within 6 h from the onset of symptoms, no large hypodensity on CT or multimodal MRI, and angiography revealed occlusion of a major cerebral artery. Recanalization rates were assessed immediately post-procedure by follow-up angiography according to the thrombolysis in cerebral infarction score criteria. Assessment of the modified Rankin Scale was performed 90 days after treatment.

RESULTS

The mean age of patients was 63.3 years, and NIHSS scores 19.12 ± 4.60 at presentation. The vessel occlusions occurred in the middle cerebral artery (68.7%), distal internal carotid artery (7.2%), internal carotid artery with tandem middle cerebral artery occlusion (14.5%), basilar artery (2.4%), and vertebral artery (7.2%). Successful recanalization (TICI 3/2b) was achieved in 56 of 83 patients (67.5%). At 90-day follow-up, good clinical outcome (mRS ≤ 2) was achieved in 33 of 83 patients (39.8%), while 20 patients died (24.1%).

CONCLUSIONS

This study revealed mechanical thrombectomy with Solitaire stent device was an effective and safe therapy, which achieved a high rate of angiographic recanalization and independent outcome accompanied by a low mortality rate.

Considerations about Occlusion of the Intracranial Distal Internal Carotid Artery

Occlusion of the intracranial distal internal carotid artery (ICA) is one of the most critical conditions among the cases of acute stroke in the anterior circulation. The introduction of selective endovascular treatment first using thrombolytic agents replaced later by the mechanical thrombectomy using various devices has improved the prognosis in a certain number of these patients. Among the factors influencing the prognosis of these patients, one is the collateral circulation which in these cases is mainly characterized by leptomeningeal anastomoses. The collateral can, however, be impaired, by distal embolization and by anomalies of the Circle of Willis: the aim of this study is to describe these aspects.

Endovascular mechanical recanalization of acute ischaemic stroke in octogenarians

BACKGROUND

Multiple studies have shown a clinical benefit of thrombectomy in acute ischaemic stroke, but most of them excluded octogenarians. The purpose of this study was to compare the outcomes between octogenarians and younger patients after thrombectomy.

MATERIALS AND METHODS

One hundred and sixty-six patients with large cerebral artery occlusion and consecutive thrombectomy were evaluated and divided into two patient age groups: younger than 80 years and older than 80 years. We compared recanalization rates, complications experienced, disability, death after discharge and at a 90-day follow-up between these age groups.

RESULTS

Sixty-eight percent of octogenarians and 72 % of younger patients were registered with successful recanalization (p = 1.0). There was no significant difference in symptomatic intracerebral haemorrhage between the groups (p = 0.32). However, octogenarians had a significantly lower rate of good clinical outcome (24 % vs. 48 %; p = 0.008) and a higher mortality rate (36 % vs. 12 %; p = 0.0013).

CONCLUSION

Octogenarians have a lower chance of good clinical outcome and a higher mortality rate despite successful recanalization. Nevertheless, 24 % of octogenarians were documented with mRS ≤2. As this age group of octogenarians will grow prospectively, careful patient selection should be mandatory when considering octogenarians for thrombectomy.

KEY POINTS

• Careful patient selection for thrombectomy should be mandatory in octogenarians. • Octogenarians have a higher mortality rate despite successful recanalization. • Nearly one-third of octogenarians were documented with a good clinical outcome.

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.

Cost-Utility Analysis of Mechanical Thrombectomy Using Stent Retrievers in Acute Ischemic Stroke

Supplemental Digital Content is available in the text.

Recently, 5 randomized controlled trials demonstrated the benefit of endovascular therapy compared with intravenous tissue-type plasminogen activator in acute stroke. Economic evidence evaluating stent retrievers is limited. We compared the cost-effectiveness of intravenous tissue-type plasminogen activator alone versus mechanical thrombectomy and intravenous tissue-type plasminogen activator as a bridging therapy in eligible patients in the UK National Health Service.

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.

Inadvertent Detachment of a Retrievable Intracranial Stent: Review of Manufacturer and User Facility Device Experience

Few systematic surveys have dealt with the potential procedural risks associated with the use of retrievable intracranial stents [Solitaire Flow Restoration (Solitaire FR)], which have become effective tools for recanalizing acutely occluded cerebral arteries. The aim of this study was to present the real-world experiences of Solitaire-FR-related adverse events by reviewing the MAUDE (Manufacturer and User Facility Device Experience) as published on the United States Food and Drug Administration website. In total, 85 adverse events related to the use of the Solitaire FR stent were reported between March 2012 and October 2014. In 80 patients these adverse events were attributable to inadvertent detachment of the device. Thirteen of these 80 patients (16%) died after the procedure. Morbidity data were available in 62 patients, among whom 11 (18%) had suffered a procedure-related injury. Detachment occurred at the first, second, and third pass in nine (21%), 21 (49%), and 13 (30%) of the 43 patients for whom this information was available, respectively. Resistance was perceived by the physician during retrieval of the device in 12 patients, and lesion characteristics were noted in 13. A rescue maneuver was reported in 20 (25%) of the 80 patients in whom the adverse event was attributable to detachment of the device, resulting in flow reestablishment in 13 (65%). The risk of inadvertent detachment during stent retrieval cannot be overemphasized in real-world scenarios, and careful consideration of the "dos and don'ts" is essential for the achievement of a safe procedure.

Acute endovascular reperfusion therapy in ischemic stroke: a systematic review and meta-analysis of randomized controlled trials

Background

Randomized controlled trials (RCTs) of endovascular therapy for acute ischemic stroke have had inconsistent results. We evaluated the efficacy and safety of endovascular therapy in published RCTs.

Methods

We performed a systematic review of RCTs of endovascular therapy with thrombolytic or mechanical reperfusion compared with interventions without endovascular therapy. Primary outcome was the frequency of good functional outcome (modified Rankin scale (mRS) of 0-2 at 90 days) and secondary outcomes were mortality at 90 days and symptomatic intracranial hemorrhage (sICH). Random-effects meta-analysis was performed and the Cochrane risk of bias assessment was used to evaluate quality of evidence.

Results

Ten studies involving 1,612 subjects were included. Endovascular therapy was not significantly associated with good functional outcome (Relative Risk [RR] =1.17; 95% CI, 0.97 to 1.42; p=0.10 and Absolute Risk Difference [ARD] =7%; 95%CI -0.1% to 14%; p=0.05); heterogeneity was moderate among studies (I²=30%). Mortality was unchanged with endovascular therapy (RR=0.92; 95 % CI, 0.75 to 1.13; p=0.45) and there was no difference in sICH (RR=1.20; 95 % CI, 0.79 to 1.82; p=0.39). The quality of evidence was low for all outcomes and the recommendation is weak for the use of endovascular therapy as per GRADE methodology.

Conclusions

Intra-arterial therapy did not show significant increase in good outcomes and no changes in either mortality or sICH in patients with acute ischemic stroke. We need further RCTs with better design and quality to evaluate the true efficacy of endovascular therapy.

Endovascular treatment of acute ischemic stroke - own experience

OBJECTIVE

Presentation of the own experience in the treatment of ischemic stroke using endovascular methods of simultaneous evaluation of their effectiveness and safety.

MATERIALS AND METHODS

The retrospective study involved a group of 18 patients hospitalized in 2005-2012 who were treated with intraarterial thrombolysis and mechanical thrombectomy. Overall there were 24 procedures performed. The investigated group consisted of seven (38.89%) women and 11 (61.11%) men. The average age of the patients was 60 years (SD ± 17, median - 60 years).

RESULTS

In 62.50% of cases (n=15) the effect of revascularization has been achieved and another 12.50% of cases (n=3) recanalization was achieved only partially. Only in 25% of procedures (n=6) failed to achieve recanalization of the artery (TICI ≤ 1). The highest percentage of recanalized arteries were obtained by following the procedure of thrombolysis targeted - 69.24% (TICI ≥ 2b). In the case of mechanical thrombectomy total patency (TICI ≥ 2b) was 54.55%. The average duration of treatment (operation) is 157 min. After 30 days successful result of the neurological status was achieved in 57.14% of patients (n=8). Full return to independent functioning as defined within 3 months after the surgery (mRS ≤ 2) reached 57.14% of patients (n=8).

CONCLUSION

Studies suggest that endovascular techniques are effective and safe in the treatment of ischemic stroke. Greater efficiency is characterized by intraarterial thrombolysis. Patients who were treated endovascular improved significantly.

Impact of temporary opening using a stent retriever on clinical outcome in acute ischemic stroke

Background

Stent retriever has a distinct ability to restore blood flow temporarily before achieving final reperfusion. There has been a limited report regarding the clinical impact of it. We investigated if temporary opening of occluded vessels using a stent retriever before final reperfusion might improve clinical outcome in acute ischemic stroke patients who received the endovascular reperfusion treatment.

Methods

We enrolled consecutive ischemic stroke patients who had an initial occlusive lesion in the anterior circulation and achieved final reperfusion (Thrombolysis In Cerebral Infarction [TICI] ≥2) by endovascular treatment. Temporary opening was defined as the presence of ante grade flow (TICI≥2) during deployment of a stent retriever. Favorable outcome was defined as a modified Rankin scale score≤2 at 90 day.

Results

A total of 98 patients were included in the study and temporary opening was achieved in 49 (50%). Temporary opening was associated with favorable outcome (odds ratio, 7.825; 95% confidence interval, 1.592–38.461; p = 0.011) in the multivariate analysis. The probability of having a favorable outcome tended to decrease as time from onset to final reperfusion increased in patients without temporary opening. However, this trend was not evident in the patient with temporary opening. The beneficial effect of temporary opening on clinical outcome seemed to be present in patients with good collaterals but not in patients with poor collaterals.

Conclusions

Temporary opening of occluded vessel using a stent retriever may be beneficial for improving clinical outcome in acute ischemic stroke patients.

Patient selection for stroke endovascular therapy--DWI-ASPECTS thresholds should vary among age groups: insights from the RECOST study

BACKGROUND AND PURPOSE

The purpose of this study was to evaluate the benefits of endovascular intervention in large-vessel occlusion strokes, depending on age class.

MATERIALS AND METHODS

A clinical management protocol including intravenous treatment and mechanical thrombectomy was instigated in our center in 2009 (Prognostic Factors Related to Clinical Outcome Following Thrombectomy in Ischemic Stroke [RECOST] study). All patients with acute ischemic stroke with an anterior circulation major-vessel occlusion who presented within 6 hours were evaluated with an initial MR imaging examination and were analyzed according to age subgroups (younger than 50 years, 50-59 years, 60-69 years, 70-79 years; 80 years or older). The mRS score at 3 months was the study end point.

RESULTS

One hundred sixty-five patients were included in the analysis. The mean age was 67.4 years (range, 29-90 years). The mean baseline NIHSS score was 17.24 (range, 3-27). The mean DWI-derived ASPECTS was 6.4. Recanalization of TICI 2b/3 was achieved in 80%. At 3 months, 41.72% of patients had a good outcome, with a gradation of prognosis depending on the age subgroup and a clear cutoff at 70 years. Only 19% of patients older than 80 years had a good outcome at 3 months (mean ASPECTS = 7.4) with 28% for 70-79 years (mean ASPECTS = 6.8), but 58% for 60-69 years (mean ASPECTS = 6), 52% for 50-59 years (mean ASPECTS = 5.91), and 72% for younger than 50 years (mean ASPECTS = 6.31). In contrast, the mortality rate was 35% for 80 years and older, and 26% for 70-79 versus 5%-9% for younger than 70 years.

CONCLUSIONS

The elderly may benefit from thrombectomy when their ischemic core volume is low in comparison with younger patients who still benefit from acute recanalization despite larger infarcts. Stroke volume thresholds should, therefore, be related and adjusted to the patient's age group.

Forced arterial suction thrombectomy with the penumbra reperfusion catheter in acute basilar artery occlusion: a retrospective comparison study in 2 Korean university hospitals

BACKGROUND AND PURPOSE

A performance of forced arterial suction thrombectomy was not reported for the treatment of acute basilar artery occlusion. This study compared revascularization performance between intra-arterial fibrinolytic treatment and forced arterial suction thrombectomy with a Penumbra reperfusion catheter in patients with acute basilar artery occlusion.

MATERIALS AND METHODS

Fifty-seven patients with acute basilar artery occlusion were treated with intra-arterial fibrinolysis (n = 25) or forced arterial suction thrombectomy (n = 32). Baseline characteristics, successful revascularization rate, and clinical outcomes were compared between the groups.

RESULTS

Baseline characteristics, the frequency of patients receiving intravenous recombinant tissue plasminogen activator, and mean time interval between symptom onset and femoral puncture did not differ between groups. The forced arterial suction thrombectomy group had a shorter procedure duration (75.5 minutes versus 113.3 minutes, P = .016) and higher successful revascularization rate (88% versus 60%, P = .017) than the fibrinolysis group. Fair outcome, indicated by a modified Rankin Scale 0-3, at 3 months was achieved in 34% of patients undergoing forced arterial suction thrombectomy and 8% of patients undergoing fibrinolysis (P = .019), and the mortality rate was significantly higher in the fibrinolysis group (25% versus 68%, P = .001). Multiple logistic regression analysis identified the forced arterial suction thrombectomy method as an independent predictor of fair outcome with adjustment for age, sex, initial NIHSS score, and the use of intravenous recombinant tissue plasminogen activator (odds ratio, 7.768; 95% CI, 1.246-48.416; P = .028).

CONCLUSIONS

In acute basilar artery occlusion, forced arterial suction thrombectomy demonstrated a higher revascularization rate and improved clinical outcome compared with traditional intra-arterial fibrinolysis. Further clinical trials with the newer Penumbra catheter are warranted.

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.

Evolution of endovascular mechanical thrombectomy for acute ischemic stroke

Acute ischemic stroke (AIS) is a common medical problem associated with significant morbidity and mortality worldwide. A small proportion of AIS patients meet eligibility criteria for intravenous thrombolysis (IVT) with recombinant tissue plasminogen activator, and its efficacy for large vessel occlusion is poor. Therefore, an increasing number of patients with AIS are being treated with endovascular mechanical thrombectomy when IVT is ineffective or contraindicated. Rapid advancement in catheter-based and endovascular device technology has led to significant improvements in rates of cerebral reperfusion with these devices. Stentrievers and modern aspiration catheters have now surpassed earlier generation devices in the degree and rapidity of revascularization. This progress has been achieved with no concurrent increase in risk of major complications or mortality, both when used alone or in combination with IVT. The initial randomized controlled trials comparing endovascular therapy to IVT for AIS failed to show superior outcomes with endovascular treatment, but key limitations of each trial may limit the significance of these results to current practice. While endovascular devices and operator experience continue to evolve, we are optimistic that this will be accompanied by improvements in patient outcomes. This review highlights the major endovascular devices used in current practice and the trials which have investigated their efficacy.

Endovascular intervention for acute ischemic stroke in light of recent trials

Three recently published trials, MR RESCUE, IMS III, and SYNTHESIS Expansion, evaluating the efficacy and safety of endovascular treatment of acute ischemic stroke have generated concerns about the future of endovascular approach. However, the tremendous evolution that imaging and endovascular treatment modalities have undergone over the past several years has raised doubts about the validity of these trials. In this paper, we review the role of endovascular treatment strategies in acute ischemic stroke and discuss the limitations and shortcomings that prevent generalization of the findings of recent trials. We also provide our experience in endovascular treatment of acute ischemic stroke.

One-year MR angiographic and clinical follow-up after intracranial mechanical thrombectomy using a stent retriever device

BACKGROUND AND PURPOSE

Little is known about the consequences of arterial wall damage that may be due to mechanical endovascular thrombectomy. Our aim was to perform 1-year MR angiographic and clinical follow-up of patients treated with mechanical endovascular thrombectomy using the Solitaire device.

MATERIALS AND METHODS

Patients with stroke treated between August 2010 and July 2012 were prospectively evaluated with a minimum follow-up of 1 year after mechanical endovascular thrombectomy. Angiographic follow-up was performed on a 3T MR imaging scanner and included intracranial artery TOF MRA and supra-aortic artery gadolinium-enhanced MRA. Images were assessed to detect arterial abnormalities (stenosis, occlusion, dilation) and were compared with the final post-mechanical endovascular thrombectomy run to differentiate delayed and pre-existing abnormalities. Clinical evaluation was performed with the mRS and the 36-Item Short-Form Health Survey questionnaire quality-of-life scale.

RESULTS

Thirty-nine patients were angiographically assessed at the mean term of 19 ± 4 months. MRA showed intracranial artery abnormalities in 10 patients, including 5 delayed intracranial artery abnormalities in 4 patients (4 stenoses and 1 dilation), 4 cases of pre-existing intracranial artery stenosis, and 2 occlusions. Pre-existing etiologic cervical artery stenosis or occlusion was observed in 2 patients. All these patients remained asymptomatic during the follow-up period. A significant clinical improvement was observed at 1-year follow-up in comparison with 3-month follow-up (P < .0001), with a good outcome achieved in 62.5% of patients and an acceptable quality of life restored.

CONCLUSIONS

One-year follow-up identifies delayed asymptomatic arterial abnormalities in patients treated with the Solitaire device.

Complications of endovascular treatment for acute stroke in the SWIFT trial with solitaire and Merci devices

BACKGROUND AND PURPOSE

Treatment of patients with ischemic stroke after endovascular treatment requires in-depth knowledge of complications. The goal of this study was to make endovascular treatment for acute ischemic stroke safer through an in-depth review of the major periprocedural complications observed in the Solitaire FR With Intention for Thrombectomy (SWIFT) trial.

MATERIALS AND METHODS

The SWIFT data base was searched for major peri-procedural complications defined as symptomatic intracranial hemorrhage within 36 hours, SAH, air emboli, vessel dissection, major groin complications, and emboli to new vascular territories.

RESULTS

Major peri-procedural complications occurred in 18 of 144 patients (12.5%) as follows: symptomatic intracranial hemorrhage, 4.9%; air emboli, 1.4%; vessel dissection, 4.2%; major groin complications, 2.8%; and emboli to new vascular territories, 0.7%. Rates of symptomatic intracranial bleeding by subtype were PH1, 0.7%; PH2, 0.7% (PH1 indicates hematoma within ischemic field with some mild space-occupying effect but involving ≤ 30% of the infarcted area; PH2, hematoma within ischemic field with space-occupying effect involving >30% of the infarcted area); intracranial hemorrhage remote from ischemic zone, 0%; intraventricular hemorrhage, 0.7%; and SAH, 3.5%. We did not observe any statistically significant associations of peri-procedural complications with age; type of treatment center; duration of stroke symptoms; NIHSS score, IV thrombolytics, atrial fibrillation, site of vessel occlusion; rescue therapy administered after endovascular treatment; or device. Comparing the Merci with the Solitaire FR retrieval device, we observed symptomatic cerebral hemorrhage (10.9% versus 1.1%; P = .013); symptomatic SAH (7.3% versus 1.1%; P = .07), air emboli (1.8% versus 1.1%; P = 1.0), emboli to new vascular territories (1.8% versus 0%; P = .38), vessel dissection (1.8% versus 4.5%; P = .65), and major groin complications (3.6% versus 7.9%; P = .48). Angiographic vasospasm was common but without clinical sequelae.

CONCLUSIONS

Understanding of procedural complications is important for treatment of patients with stroke after endovascular treatment. We observed fewer endovascular complications with the Solitaire FR device treatment compared with Merci device treatment, particularly symptomatic cerebral hemorrhage.

Prehospital stroke diagnostics based on neurological examination and transcranial ultrasound

BACKGROUND

Transcranial color-coded sonography (TCCS) has proved to be a fast and reliable tool for the detection of middle cerebral artery (MCA) occlusions in a hospital setting. In this feasibility study on prehospital sonography, our aim was to investigate the accuracy of TCCS for neurovascular emergency diagnostics when performed in a prehospital setting using mobile ultrasound equipment as part of a neurological examination.

METHODS

Following a '911 stroke code' call, stroke neurologists experienced in TCCS rendezvoused with the paramedic team. In patients with suspected stroke, TCCS examination including ultrasound contrast agents was performed. Results were compared with neurovascular imaging (CTA, MRA) and the final discharge diagnosis from standard patient-centered stroke care.

RESULTS

We enrolled '232 stroke code' patients with follow-up data available in 102 patients with complete TCCS examination. A diagnosis of ischemic stroke was made in 73 cases; 29 patients were identified as 'stroke mimics'. MCA occlusion was diagnosed in ten patients, while internal carotid artery (ICA) occlusion/high-grade stenosis leading to reversal of anterior cerebral artery flow was diagnosed in four patients. The initial working diagnosis 'any stroke' showed a sensitivity of 94% and a specificity of 48%. 'Major MCA or ICA stroke' diagnosed by mobile ultrasound showed an overall sensitivity of 78% and specificity of 98%.

CONCLUSIONS

The study demonstrates the feasibility and high diagnostic accuracy of emergency transcranial ultrasound assessment combined with neurological examinations for major ischemic stroke. Future combination with telemedical support, point-of-care analysis of blood serum markers, and probability algorithms of prehospital stroke diagnosis including ultrasound may help to speed up stroke treatment.

Comparison of stent retriever and intra-arterial fibrinolysis in patients with acute ischaemic stroke

BACKGROUND AND PURPOSE

Although the stent retriever (SR) has shown a better reperfusion rate and clinical outcome than the older generation mechanical clot retrieval device, it is uncertain whether the SR is superior to intra-arterial fibrinolysis (IAF).

METHODS

Ischaemic stroke patients who were treated with SR or IAF as initial endovascular treatment modality for unilateral arterial occlusion in the anterior circulation were included. Successful reperfusion was defined as Thrombolysis in Cerebral Infarction grade ≥2b. A favourable clinical outcome was defined as a modified Rankin Score ≤2 at 3 months.

RESULTS

Between January 2009 and May 2012, 55 patients were treated with SR and 50 patients were treated with IAF. The baseline characteristics were similar between the two groups except for the occlusion site and rescue treatment. In binary logistic regression analysis adjusted for the occlusion site and rescue treatment, SR was independently associated with increased successful reperfusion [82.0% vs. 47.3%; odds ratio (OR) 5.21; 95% confidence interval (CI) 1.92-14.14) and a more favourable clinical outcome at 3 months (54.0% vs. 43.6%; OR 3.40; 95% CI 1.31-8.84). The frequency of symptomatic intracranial haemorrhage and mortality at 3 months was not different between the two groups.

CONCLUSIONS

Stent retriever was as safe as and more effective than IAF. Our findings suggest that SR may be considered as an initial modality rather than IAF in acute stroke patients who undergo endovascular treatment.

Solitaire Flow Restoration thrombectomy for acute ischemic stroke: retrospective multicenter analysis of early postmarket experience after FDA approval

BACKGROUND

The promising results of the Solitaire Flow Restoration (FR) With the Intention for Thrombectomy (SWIFT) trial recently led to Food and Drug Administration (FDA) approval of the Solitaire FR stent retriever device for recanalization of cerebral vessels in patients with acute ischemic stroke.

OBJECTIVE

To report the early postmarket experience with this device since its FDA approval in the United States, which has not been previously described.

METHODS

We conducted a retrospective analysis of consecutive acute ischemic strokes cases treated between March 2012 and July 2012 at 10 United States centers where the Solitaire FR was used as a single device or in conjunction with other intraarterial endovascular approaches.

RESULTS

A total of 101 patients were identified (mean age, 64.7 years; mean admission National Institutes of Health Stroke Scale [NIHSS] score, 17.6). Intravenous thrombolysis was administered in 39% of cases; other endovascular techniques were utilized in conjunction with the Solitaire FR in 52%. Successful recanalization (Thrombolysis in Myocardial Infarction 2/3) was achieved in 88%. The rate of symptomatic intracranial hemorrhage within the first 24 hours was 15%. In-hospital mortality was 26%. At 30 days, 38% of patients had favorable functional outcome (modified Rankin scale score ≤2). Severity of NIHSS score on admission was a strong predictor of poor outcome.

CONCLUSION

Our study shows that a variety of other endovascular approaches are used in conjunction with Solitaire FR in actual practice in the United States. Early postmarket results suggest that Solitaire FR is an effective tool for endovascular treatment of acute ischemic stroke.

Solitaire FR as a first-line device in acute intracerebral occlusion: a single-centre retrospective analysis

INTRODUCTION

Analysing the clinical and angiographical effectiveness of the Solitaire FR as a mechanical thrombectomy device in acute intracerebral occlusion.

METHODS

Sixty-two patients were retrospectively included between January 2010 and March 2012. All of them underwent mechanical thrombectomy with the Solitaire FR device with or without intravenous thrombolysis. Twenty-five patients had an occlusion of the basilar artery, 1 had a posterior cerebral artery occlusion. There were 16 M1 middle cerebral artery occlusions, 9 carotid T occlusions and 11 tandem occlusions. Clinical status was evaluated using the National Institute of Health Stroke Scale (NIHSS) before and 24 hours after treatment and at discharge. The Modified Rankin Scale (mRS) was evaluated at 3 months.

RESULTS

Mean age of patients was 64.8 years. Mean NIHSS score on admission was 19.8. Stand-alone thrombectomy was used in 47 patients (75.8%). Recanalization was successful (TICI score 2b or 3) in 23 of 26 (88.5%) patients with posterior circulation occlusion and in 23 of 36 (63.9%) patients with anterior circulation occlusion. NIHSS improved by more than 10 points for 15 of 59 patients with initial NIHSS over 10. MRS was 0-2 in 25 of 62 patients (40.3%). Overall, 23 patients out of 62 died (37%). No complications related to the Solitaire device occurred.

CONCLUSION

These results confirm that the Solitaire FR device is safe and effective in stand-alone thrombectomy.

Fate of the penumbra after mechanical thrombectomy

BACKGROUND AND PURPOSE

In acute stroke, CTP is often used to visualize the endangered brain areas, including the ischemic core and the penumbra. Our goal was to assess the evolution of the infarct after mechanical thrombectomy and to analyze the interventional factors determining the fate of the penumbra.

MATERIALS AND METHODS

All patients receiving mechanical thrombectomy in the anterior circulation and receiving CTP beforehand were identified. The infarct volume was specified. The clinical parameters, outcome, and interventional results were correlated with the CTP and the final infarct size.

RESULTS

In total, 73 patients were included. After mechanical thrombectomy, 78.1% reached a TICI score of 3/2b. The final infarct volume was significantly smaller, with a TICI score of 3/2b compared with less sufficient recanalization (19.60 ± 3 cm(3) versus 38.1 ± 9 cm(3); P < .001). After TICI 3/2b recanalization, 81% ± 5.2% of the potential infarct size (calculated as the sum of infarct core and penumbra) could be rescued. In patients with TICI scores of 2a or worse, only 39 ± 28.3 were salvaged (P < .001). The Alberta Stroke Program Early CT Score after successful recanalization TICI score of 3/2b resulted in a decline of 1.9 ± 1.4 compared with the significantly higher degradation score of 3.7 ± 1.7 after recanalization, with a TICI score of 2a or worse. A recanalization TICI score of 3/2b resulted in an NIHSS improvement of 7.3 ± 0.8 NIHSS points, whereas a poorer recanalization improved on the NIHSS by only 2.5 ± 1.5 points (P < .01).

CONCLUSIONS

Mechanical thrombectomy is a potent method to rescue large areas of penumbra in acute stroke.