Endovascular Treatment of Acute Intracerebral Artery Occlusions with the Solitaire Stent: Single-Centre Experience with 108 Recanalization Procedures

Evaluation of pure subarachnoid hemorrhage after mechanical thrombectomy in a series of 781 consecutive patients

INTRODUCTION

Subarachnoid hyperdensity is commonly seen on postoperative computed tomography scans within 24 h after mechanical thrombectomy. The impact on patients' outcomes remains uncertain. We present a real-world experience evaluating periprocedural factors associated with the development of subarachnoid hemorrhage (SAH) and its impact on outcomes of patients with acute stroke undergoing mechanical thrombectomy.

METHODS

A single-center, retrospective analysis was performed between January 2016 and August 2021, including all consecutive patients who underwent thrombectomy. Our study aimed to evaluate periprocedural factors associated with subarachnoid hemorrhage within 24 h of the intervention, and the potential impact on patients' outcome.

RESULTS

Of 781 patients, 44 patients (5.63%) demonstrated pure SAH within 24 h of the intervention. Patients from the SAH group were more likely to have tandem occlusion (15.9% vs. 5.2%, p = .003), aspiration using reperfusion pump system (81.4% vs. 66.8%, p = .047), intraoperative complications (9.1% vs. 0.9%; p < .001), longer puncture-to-recanalization times (45 min vs 29 min, p = .042) and a higher median number of passes to achieve recanalization (1 vs. 3, p = .002). There was no statistically significant difference in the long-term functional outcome between the groups.

CONCLUSION

We suggest that dual-energy computed tomography could better distinguish between blood and pure contrast stagnation. Still, SAH was not associated with an unfavorable outcome in stroke patients undergoing thrombectomy.

Modification by an aspiration catheter for vessel stretching in thrombectomy using a stent retriever in vitro

OBJECTIVES

Post-thrombectomy subarachnoid hemorrhage, which is caused by vessel stretching when retrieving a stent retriever (SR), is a complication of endovascular mechanical thrombectomy (EVT) using an SR. This in vitro study examined the association between EVT for middle cerebral artery (MCA) occlusion and M2 vessel stretching depending on the positioning of the SR or combined use of SR and aspiration catheter (AC) technique (CBT).

MATERIALS AND METHODS

A silicone vascular model was used. The maximum migration distance (MMD) in the anteroposterior view of an X-ray impermeable metal marker located at an M2 trunk 20 mm distal to the M1-2 bifurcation in angiographic images during an SR retrieval was calculated. According to the positioning of SR deployment (distal or proximal) and use of an AC [SR alone without an AC (SR alone) group, stent retrieval into an AC (SA) group, and stent-AC retrieval as a unit into a guiding catheter (SA unit) group], 60 attempts were conducted with each group of 10 attempts.

RESULTS

In distal SR deployment, the MMD in the CBT group, consisting of SA and SA unit groups, was significantly smaller than the SR alone group (1.36 ± 0.32 mm VS 2.39 ± 1.10 mm; p = 0.001). In proximal SR deployment, the CBT group showed a tendency to decrease MMD (1.38 ± 0.33 mm VS 1.63 ± 0.28 mm; p = 0.077).

CONCLUSIONS

This in vitro study showed that CBT might help modify the stretching of M2 when an SR is distally deployed in MCA occlusion.

Mechanical thrombectomy in stroke patients with acute occlusion of the M1- compared to the M2-segment: Safety, efficacy, and clinical outcome

PURPOSE

Endovascular treatment (ET) in occlusions of the M1- and proximal M2-segment of the middle cerebral artery (MCA) is an established procedure. In contrast, ET in distal M2-occlusions has not been sufficiently evaluated yet. The purpose of this study was to assess relevant parameters for clinical outcome, efficacy, and safety of patients undergoing ET in M1-, proximal M2-, and distal M2-occlusions.

METHODS

One hundred seventy-four patients undergoing ET in acute ischemic stroke with an occlusion of the M1- or M2-segment of the MCA were enrolled prospectively. Non-parametric analysis of variance in 3-month mRS, TICI scale, and complication rates were performed with Kruskal-Wallis test between M1- and proximal and distal M2-occlusions. Subsequent pairwise group comparisons were calculated using Mann-Whitney U-tests. Binary logistic regression models were calculated for each occlusion site.

RESULTS

There were no significant group differences in 3-month mRS, mTICI scale, or complication rates between M1- and M2-occlusions nor between proximal and distal M2-occlusions. Binary logistic regression in patients with M1-occlusions showed a substantial explanation of variance (NR2=0.35). NIHSS (p=0.009) and Maas Score as parameter for collateralization (p=0.01) appeared as significant contributing parameters. Binary logistic regression in M2-occlusions showed a high explanation of variance (NR2=0.50) of mRS but no significant factors.

CONCLUSIONS

Clinical outcome and procedural safety of patients with M2-occlusions undergoing ET are comparable to those of patients with M1-occlusions. Clinical outcome of patients with M1-occlusions undergoing ET is primarily influenced by the initial neurological deficit and the collateralization of the occlusions. By contrast, clinical outcome in patients with M2-occlusions undergoing ET is more multifactorial.

Stentrievers : An engineering review

The advent of endovascular therapy for acute large vessel occlusion has revolutionized stroke treatment. Timely access to endovascular therapy, and the ability to restore intracranial flow in a safe, efficient, and efficacious manner has been critical to the success of the thrombectomy procedure. The stentriever has been a mainstay of endovascular stroke therapy, and current guidelines recommend the usage of stentrievers in the treatment of large vessel occlusion stroke. Despite the success of existing stentrievers, there continues to be significant development in the field, with newer stentrievers attempting to improve on each of the three key aspects of the thrombectomy procedure. Here, we elucidate the technical requirements that a stentriever must fulfill. We then review the basic variables of stent design, including the raw material and its form, fabrication method, geometric configuration, and further additions. Lastly, a selection of stentrievers from successive generations are reviewed using these engineering parameters, and clinical data is presented. Further avenues of stentriever development and testing are also presented.

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.

Solitaire Stentectomy Using a Stent-Retriever Technique in a Porcine Model

PURPOSE

Mechanical thrombectomy using the Solitaire device has become a standard treatment of ischemic stroke due to large vessel occlusions. Inadvertent detachment is a feared complication, which is associated with poor clinical outcome. The aim of this experimental study was to assess in a porcine model the feasibility and effectiveness of rescuing detached Solitaire devices using different stent retrievers.

METHODS

Solitaire FR devices (4 × 15/20 mm and 6 × 20/30 mm) were placed in the axillary artery of pigs. By means of 3 different stent retrievers (Trevo ProVue; EmboTrap II revascularization device; 3D revascularization device) a total of 24 rescue maneuvers (8 per retriever) were performed by deploying the retrievers within the deployed Solitaire devices and trapping parts of the Solitaire within the microcatheter. Rescue rates, rescue time and complications were assessed.

RESULTS

Overall stentectomy of the Solitaire devices was successful in all cases (100%). Time of rescue was comparable using the applied stent retrievers (Trevo ProVue; EmboTrap II revascularization device; 3D revascularization device). Complications, such as entrapment of the Solitaire-retriever complex at the intermediate catheter, Solitaire migration, vasospasm, perforation, or dissection were not observed.

CONCLUSION

Stentectomy of inadvertently detached Solitaire devices using different stent retrievers is a feasible and effective method. Rescue rates and times with the Trevo ProVue, EmboTrap II and 3D revascularization device were comparable.

Endovascular Metal Devices for the Treatment of Cerebrovascular Diseases

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

Acute Occlusion of the Distal Internal Carotid Artery : Single Center Experience in 46 Consecutive Cases, review of the literature and proposal of a classification

PURPOSE

The acute distal intracranial occlusion of the internal carotid artery (ICA) is a very complex heterogeneous pathology, characterized by various patterns. Aim of this work is to identify the different types and propose a classification.

METHODS

Among the patients admitted for stroke in the anterior circulation from august 2014 to October 2017, 46 (25%) presented with intracranial distal carotid artery occlusion. The mean age of the patients was 71 (SD 13.7), 65,2% female. The protocol included general and specific neurological examinations, CT, CT-Angiography with multiphase CTA, followed by Angiography. The occlusion was treated by aspiration device alone or associated with stent-retriever. NIHSS at the admission, at discharge and modified ranking Scale (mRS) at four months were examined.

RESULTS

The occlusions presented with various patterns. Depending on its site (located at the distal ICA bifurcation or more proximal at the level of the ophthalmic segment of ICA, with or without extent to ICA bifurcation) taking also into account the various involvement of the cerebral vessels and anatomic variations of Circle of Willis, three groups of occlusion types could be identified (T1, T2 and T3). The collateral circulation, and the possibilities of the endovascular revascularization important for the final outcome, were clearly connected with the type of occlusion. NIHSS at admission was 19.1 (Range from 8 to 30, SD 4.4). Good outcome defined as mRS 0-2 at for months was obtained in 17 patients (37%).

CONCLUSIONS

The proposed classification reproduces more precisely the complexity and heterogeneity of this pathology, being useful in the diagnosis and treatment of these patients.

Rescue Glue Embolization of Vessel Perforation During Mechanical Thrombectomy for Acute Ischemic Stroke: Technical Note

BACKGROUND

Vessel perforation is a serious technical complication during mechanical thrombectomy (MT) for the treatment of acute ischemic stroke with large vessel occlusion. Routine rescue strategy includes balloon occlusion for tamponade, procedure suspension, and lowering or normalizing blood pressure. However, this complication is still associated with poor outcome and high mortality.

METHODS

In this paper, the authors report their experience by using glue to embolize the ruptured vessel secondary to microcatheter/microwire perforation, preventing further deterioration in clinical outcome. Rescue glue embolization was attempted in 2 patients who developed intraprocedural vessel perforation while trying to gain access through the blocked artery with a microcatheter/microwire.

RESULTS

The ruptured vessels were effectively occluded. Stent retriever thrombectomies were then continued, and TICI 2b and 3 recanalizations were achieved. Both patients' neurologic status improved.

CONCLUSIONS

The key benefit of this method exists in embolizing the ruptured vessel without affecting the following MT. We propose the rescue glue embolization is simple yet effective in managing vessel perforation complication during MT.

[Efficacy of combined ultrasound and microbubble treatment for thrombolysis for rescuing ischemic tissues in rats at different time after thrombosis]

OBJECTIVE

To explore the relationship between the time after thrombosis and the efficacy of combined ultrasound and microbubble treatment for rescuing the ischemic tissues.

METHODS

Rat models of thrombosis in the right common iliac artery were established and received combined ultrasound and microbubble treatment at 3, 6 and 12 h after thrombosis. The recanalization rate of the right common iliac artery was assessed using both 2-dimensional and Doppler ultrasound. The plateau acoustic intensity (AI) was quantified for estimating the skeletal microvascular blood volume, and skeletal muscle injury markers including myoglobin (Mb) and creatinine kinase (CK) were measured using ELISA. Postmortem TUNEL staining was used to detect the apoptotic rate of skeletal muscle cells in the hind limb of the rats.

RESULTS

Compared with those in 3 h group, the recanalization rate and AI were significantly lower, and the levels of Mb and CK and the apoptotic rate of the skeletal muscle cells were significantly higher in both 6 h group and 12 h group (P &lt; 0.05). Compared with those in 6 h group, the rats receiving treatment at 12 h after thrombosis showed significantly lowered AI and increased Mb, CK and apoptotic rate of the skeletal muscle cells (P &lt; 0.05).

CONCLUSIONS

The efficacy of combined ultrasound and microbubble treatment for rescuing ischemic tissues tends to be attenuated as the time after thrombosis prolongs in rats.

Iatrogenic Removal of the Intima in the Middle Cerebral Artery by a Stent Retriever: A Report of Two Cases

BACKGROUND

Mechanical thrombectomy improves functional outcomes in patients with acute ischemic stroke. However, stent retrievers have the risk of vascular damage.

CASE DESCRIPTION

We present 2 cases of patients with acute internal carotid artery occlusion who experienced removal of the intima by a stent retriever. In both patients, a 6 × 30-mm Solitaire stent was fully deployed from the M2 portion and slowly withdrawn. White membranes were retrieved outside the strut in both patients. Histopathologic examination showed that one membrane consisted of thickened intima and internal elastic lamina and the other consisted of calcified intima and internal elastic lamina. One patient who suffered embolic stroke experienced recurrent infarction within 24 hours after operation, and the damaged vessel was occluded on magnetic resonance angiography 21 days after stroke. In another patient with carotid artery dissection, the damaged vessel showed asymptomatic stenosis on magnetic resonance angiography 90 days after stroke. Arteries with both atherosclerosis and vessel dissection may be vulnerable to high radial expansion force.

CONCLUSIONS

Full deployment of a relatively large-sized stent into a vulnerable vessel may cause vessel dissection after removal of the intima. Appropriate material selection and treatment strategy while considering stroke etiology and the occlusion site are important to prevent vessel damage.

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.

Posterior Circulation Occlusions May Be Associated with Distal Emboli During Thrombectomy : Factors for Distal Embolization and a Review of the Literature

Background

Distal embolization or movement of the thrombus to previously uninvolved vasculature are feared complications during stroke thrombectomy. We looked at associated factors in a consecutive series of patients who underwent thrombectomy with the same endovascular device.

Methods

We included all patients with acute ischemic stroke in the anterior or posterior circulation, who underwent thrombectomy with the same thrombectomy device for acute stroke from 2013 to 2016. Distal embolization was defined as any movement of the thrombus into a previously uninvolved portion of the cerebral vasculature or the presence of thrombotic material further downstream in the affected vessel, which occurred after the initial angiogram. We studied patient-related as well as technical factors to determine their association with distal emboli.

Results

In this study 167 consecutive acute stroke patients treated with the emboTrap® device (Cerenovus, Irvine, CA, USA) were included with a median National Institutes of Health Stroke Scale (NIHSS) of 15 (range 2–30) and mean age of 67 years (SD 13.1 years). Of the patients in our cohort 20 (11.9%) experienced distal emboli, with 2.3% into a new territory and 9.6% into a territory distal to the primary occlusion. On univariate analysis, age, intravenous tissue plasminogen activator (tPA), posterior circulation occlusions, and general anesthesia were associated with distal emboli. On multivariate analysis, only posterior circulation occlusions (odds ratio OR 4.506 95% confidence interval CI 1.483–13.692, p = 0.008) were significantly associated with distal emboli. Distal embolization was not significantly associated with worse functional outcomes at 3 months, increased mortality or increased bleeding risk.

Conclusion

Posterior circulation occlusions were significantly associated with distal emboli during thrombectomy, possibly due to the lack of flow arrest during such procedures. New techniques and devices should be developed to protect against embolic complications during posterior circulation stroke thrombectomy.

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.

Equivalent favorable outcomes possible after thrombectomy for posterior circulation large vessel occlusion compared with the anterior circulation: the MUSC experience

Introduction

In acute ischemic stroke (AIS), posterior circulation large vessel occlusions (LVOs) have been associated with poorer outcomes compared with anterior circulation LVOs. The outcomes of anterior versus posterior circulation thrombectomy for LVOs were compared at a high volume center employing a direct aspiration first pass technique (ADAPT).

Methods

We retrospectively studied a database of AIS cases that underwent ADAPT thrombectomy for LVOs. Cases were grouped by anatomical location of thrombectomy (posterior vs anterior circulation), and analysis was performed on both entire sample size.

Results

A total of 436 AIS patients (50.2% women, mean age 67.3 years) underwent ADAPT thrombectomy for LVO during the study period, of whom 13% of had posterior circulation thrombectomy. Patients with posterior circulation thrombectomy did not show a significant difference in preprocedural variables, including age, baseline National Institutes of Health Stroke Scale (NIHSS), and onset to groin time, compared with anterior circulation (P>0.05). There were also no differences in procedural variables between the two groups. Patients in the posterior group were found to have a similar likelihood of good outcome (modified Rankin Scale score 0—2) at 90 days compared with the anterior group (42.9% vs 43.2%, respectively), and a small but not significant increase in mortality at 90 days. Multilogistic regression analysis showed that the anatomical location (anterior vs posterior) was not an independent predictor of good outcome or mortality after thrombectomy. Prominent predictors of outcome/mortality included age, female gender, procedure time, and baseline NIHSS.

Conclusions

Our findings demonstrate that when patients are carefully selected for thrombectomy, those with posterior circulation LVOs can achieve similar outcomes compared with anterior circulation thrombectomy, indicating comparable safety and efficacy profiles.

Effective use of balloon guide catheters in reducing incidence of mechanical thrombectomy related distal embolization

BACKGROUND AND PURPOSE

The clinical benefit of endovascular stroke therapy has been demonstrated in several prospective randomized trials. However, in a relevant percentage of patients, mechanical thrombectomy bears the risk of causing new infarction in initially unaffected vascular territories through thrombus fragmentation and migration of clot debris. The goal of this study was to evaluate the use of the balloon guide catheter (BGC) to effectively achieve flow arrest and thrombus aspiration during the intervention to avoid distal embolization.

METHODS

A retrospective study was performed in 139 patients between October 2010 and May 2016 to analyze occlusions in the middle cerebral artery (MCA) or internal carotid artery (ICA) by using a stent retriever with a BGC (n = 73) or a non-BGC (n = 66). The following data were collected: patient age and gender, along with history of diabetes mellitus, hypertension, atrial fibrillation, smoking, obesity, dyslipidemia, and previous ischemic stroke. Data on procedure time, number of passes, and angiographic findings were also collected. The final reperfusion score was rated based on the Thrombolysis in Cerebral Infarction (TICI) grading scale. Successful recanalization was defined as TICI 3 or 2b.

RESULTS

A total of 139 patients underwent mechanical thrombectomy with the stent retriever. Of the 139 patients, 73 (52.5%) underwent placement of a BGC. The mean age was 65.8 ± 13.5 years, and the median National Institutes of Health Stroke Scale (NIHSS) score was 11. The average initial NIHSS score was lower in the BGC group compared with the non-BGC group (mean, 11.2 ± 5.6 vs. 13.2 ± 5.6; P = 0.03). Patients with BGC had fewer incidences of previous ischemic stroke (12.3% vs. 28.8%; P = 0.01). The numbers of passes were similar between the two groups. The procedure time (99 ± 49.4 min vs. 124 ± 72.2 min; P = 0.02) and the time from onset of symptoms to procedure end (302 ± 102 min vs. 357.2 ± 136.1 min; P = 0.009) were shorter in the BGC group. TICI 3 or 2b recanalization scores were higher in the BGC group compared to the non-BGC group [63/73, 86.3% vs. 48/66, 72.7%; odds ratio (OR), 0.6; 95% confidence interval (CI), 0.2-1.4; P = 0.04]. Importantly, distal embolization was less frequent in the BGC group (5/73, 6.8% vs. 21/66, 31.8%; OR, 6.3; 95% CI, 2.2-18.0; P < 0.001).

CONCLUSIONS

The risk of distal embolization was significantly decreased with the use of a BGC.

Incomplete Large Vessel Occlusions in Mechanical Thrombectomy: An Independent Predictor of Favorable Outcome in Ischemic Stroke

BACKGROUND AND PURPOSE

Cerebral large vessel occlusion (LVO) in acute ischemic stroke (AIS) may be complete (CLVO) or incomplete (ILVO). The influence of ILVO on clinical outcome after mechanical thrombectomy (MT) remains unclear. We investigated primarily the clinical outcome in patients with AIS due to ILVO or CLVO.

METHODS

Five hundred three consecutive AIS patients with LVO treated with stent-retriever or direct aspiration-based MT between 2010 and 2016 were analyzed. The primary endpoint was favorable clinical outcome (modified Rankin Scale ≤2) at 90 days; secondary endpoints were periprocedural parameters.

RESULTS

Forty-nine patients (11.3%) with a median National Institutes of Health Stroke Scale (NIHSS) of 11 presented with ILVO and the remainder presented with CLVO and median NIHSS of 15 (p < 0.001). The median groin puncture-to-reperfusion time was 30 vs. 67 min, respectively (p < 0.001). Successful reperfusion was reached in 47 out of 49 ILVO (95.9%) vs. 298 out of 381 CLVO (78.2%; p < 0.005) with less retrieval maneuvers (1.7 ± 2.2 vs. 3.0 ± 2.5; p < 0.001). The favorable outcome at 90 days was 81% in patients with ILVO vs. 29.1% in CLVO (p < 0.001); respective all-cause mortality rates were 6.4 vs. 28.5% (p < 0.001). Periprocedural complications (6.9%) occurred exclusively in CLVO patients (p < 0.05). ILVO was associated with favorable clinical outcome independent of age and NIHSS in multivariate logistic regression both in the anterior (OR 3.6; 95% CI 1.8-6.9; p < 0.001) and posterior circulation (OR 3.5; 95% CI 1.8-6.9; p < 0.001).

CONCLUSIONS

AIS due to ILVO is frequent and is associated with a nearly threefold higher chance of favorable clinical outcome at 90 days, independent of age and initial NIHSS compared to CLVO.

Vessel perforation during stent retriever thrombectomy for acute ischemic stroke: technical details and clinical outcomes

BACKGROUND

Vessel perforation during stent retriever thrombectomy is a rare complication; typically only single instances have been reported.

OBJECTIVE

To report on a series of patients whose stent retriever thrombectomy was complicated by intraprocedural vessel perforation and discuss its potential mechanisms, rescue treatment strategies, and clinical significance.

METHODS

Cases with intraprocedural vessel perforation, where a stent retriever was used either as a primary treatment approach or as a part of a direct aspiration first pass technique (ADAPT), were included in the final analysis. Clinical data, procedural details, radiographic and clinical outcomes were collected from nine participating centers.

RESULTS

Intraprocedural vessel perforation during stent retriever thrombectomy occurred in 16 (1.0%) of 1599 cases. 63% of intraprocedural perforations occurred at distal locations. Endovascular rescue techniques (most commonly, intracranial balloon occlusion for tamponade) were attempted in 50% of cases. Procedure was aborted without any rescue attempts in 44% of cases. Mortality during hospitalization and at 3 months was 56% and 63%, respectively. 25% of patients achieved good functional outcome at 3 months after the procedure.

CONCLUSIONS

Intraprocedural perforations during stent retriever thrombectomy were rare, but when they occurred were associated with high mortality. Perforations most commonly occurred at distal occlusion sites and were often characterized by difficulty traversing the occlusion with a microcatheter or microwire, or while withdrawing the stent retriever. Nevertheless, 25% of patients had a favorable functional outcome, suggesting that in some patients with this complication good neurological recovery is achievable.

Mechanical Solitaire Thrombectomy with Low-Dose Booster Tirofiban Injection

PURPOSE

Mechanical thrombectomy using a Solitaire stent has been associated with a high recanalization rate and favorable clinical outcome in intra-arterial thrombolysis. To achieve a higher recanalization rate for mechanical Solitaire thrombectomy, we used an intra-arterial low-dose booster tirofiban injection into the occluded segment after stent deployment. We report the safety and recanalization rates for mechanical Solitaire thrombectomy with a low-dose booster tirofiban injection.

MATERIALS AND METHODS

Between February and March 2013, 13 consecutive patients underwent mechanical Solitaire thrombectomy with low-dose booster tirofiban injection. The occlusion sites included the proximal middle cerebral artery (5 patients), the internal carotid artery (5 patients), the top of the basilar artery (2 patients) and the distal middle cerebral artery (M2 segment, 1 patient). Six patients underwent bridge treatment, including intravenous tissue plasminogen activator. Tirofiban of 250 µg was used in all patients except one (500 µg). All occluded vessels were recanalized after 3 attempts at stent retrieval (1 time, n=9; 2 times, n=2; 3 times, n=2).

RESULTS

Successful recanalization was achieved in all patients (TICI 3, n=8; TICI 2b, n=5). Procedural complications developed in 3 patients (subarachnoid hemorrhage, n=2; hemorrhagic transformation, n=1). Mortality occurred in one patient with a basilar artery occlusion due to reperfusion brain swelling after mechanical Solitaire thrombectomy with low-dose booster tirofiban injection. Favorable clinical outcome (mRS≤2) was observed in 8 patients (61.5%).

CONCLUSION

Our modified mechanical Solitaire thrombectomy method using a low-dose booster tirofiban injection might enhance the recanalization rate with no additive hemorrhagic complications.

Safety and Efficacy of Mechanical Thrombectomy in Acute Ischemic Stroke of Anticoagulated Patients-A Prospective Observational Study

BACKGROUND

Anticoagulated patients (APs) are excluded from the acute stroke management with alteplase in Europe, not in the United States. They could benefit from mechanical thrombectomy (MT), which was not undoubtedly proven. There are scarce data about its results in such patients. The authors' aim is to analyze the efficacy and safety of MT in APs presenting with an acute stroke in our institution.

METHODS

Prospective observational study comparing 30 APs and 109 non-anticoagulated patients (N-APs) underwent direct MT without alteplase. Demographic data, clinical severity (National Institutes of Health Stroke Scale [NIHSS]), efficacy (recanalization thrombolysis in cerebral infarction [TICI] ≥ 2b and modified Rankin Scale score ≤ 2 at 3 months), and security (symptomatic intracranial hemorrhage [SICH], mortality at 3 months) were compared between both groups.

RESULTS

In both groups men were more frequent (63.3% of APs were men and 61.5% of N-APs were men). Mean age was 73 in APs and 67.2 in N-APs. Median NIHSS was similar (17 APs; 16 N-APs), also TICI greater than or equal to 2b (93.3% APs; 89.9% N-APs). The 3-month modified Rankin Scale score less than or equal to 2 was 46.7% in APs and 55.2% in N-APs (P = .40). SICH was present in 16.7% of APs and 8.3% of N-APs (P = .15). Mortality at 3 months was 6.7% in APs and 19% in N-APs (P = .08).

CONCLUSIONS

MT is a valid treatment option in APs. It achieves an efficacy as in N-APs with a tendency to suffer more from SICH, but lower mortality. We hypothesize that cardioembolic clots may be easier to be removed than atherotrombotics, and that embolic stroke in APs might be less severe than that in N-APs or might suffer less of other complications than atherotrombotics.

Mechanical Thrombectomy in Patients with Acute Ischemic Stroke and Lower NIHSS Scores: Recanalization Rates, Periprocedural Complications, and Clinical Outcome

BACKGROUND AND PURPOSE

Mechanical thrombectomy, in addition to intravenous thrombolysis, has become standard in acute ischemic stroke treatment in patients with large-vessel occlusion in the anterior circulation. However, previous randomized controlled stroke trials were not focused on patients with mild-to-moderate symptoms. Thus, there are limited data for patient selection, prediction of clinical outcome, and occurrence of complications in this patient population. The purpose of this analysis was to assess clinical and interventional data in patients treated with mechanical thrombectomy in case of ischemic stroke with mild-to-moderate symptoms.

MATERIALS AND METHODS

We performed a retrospective analysis of a prospectively collected stroke data base. Inclusion criteria were anterior circulation ischemic stroke treated with mechanical thrombectomy at our institution between September 2010 and October 2015 with an NIHSS score of ≤8.

RESULTS

Of 484 patients, we identified 33 (6.8%) with the following characteristics: median NIHSS = 5 (interquartile range, 4-7), median onset-to-groin puncture time = 320 minutes (interquartile range, 237-528 minutes). Recanalization (TICI = 2b-3) was achieved in 26 (78.7%) patients. Two cases of symptomatic intracranial hemorrhage were observed. Favorable (mRS 0-2) and moderate (mRS 0-3) clinical outcome at 90 days was achieved in 21 (63.6%) and 30 (90.9%) patients, respectively.

CONCLUSIONS

The clinical outcome of patients undergoing mechanical thrombectomy for acute ischemic stroke with mild stroke due to large-vessel occlusion appears to be predominately favorable, even in a prolonged time window. However, although infrequent, angiographic complications could impair clinical outcome. Future randomized controlled trials should assess the benefit compared with the best medical treatment.

Outcomes of stent retriever thrombectomy in basilar artery occlusion: an observational study and systematic review

BACKGROUND

Basilar artery occlusion (BAO) remains one of the most devastating subtypes of stroke with high mortality and poor outcome. Early recanalisation is the most powerful predictor of favourable outcome in patients with stroke, and may be improved with mechanical thrombectomy using stent retriever devices. However, the benefit in functional outcome and safety of stent retrievers are not yet well known. The aim of this study was to assess efficacy and safety profiles of stent retriever thrombectomy in BAO patients with stroke.

METHODS

We analysed data retrospectively from our consecutive clinical series and conducted a systematic review and meta-analysis of all previous studies of stent retriever thrombectomy in BAO patients with stroke between November 2010 and April 2014.

RESULTS

From March 2010 to March 2013, 22 patients with acute BAO were treated with a Solitaire stent retriever in our series. Favourable outcome was significantly associated with younger age and distal BAO. The literature search identified 15 previous studies involving a total of 312 subjects. In the meta-analysis, including our series data, the recanalisation rate (Thrombolysis In Cerebral Infarction (TICI) score ≥ 2b) reached 81% (95% CI 73% to 87%). The rate of symptomatic intracranial haemorrhage was 4% (95% CI 2% to 8%), favourable outcome (modified Rankin Scale (mRS) ≤ 2 at 3 months) was found in 42% (95% CI 36% to 48%) and mortality rate was 30% (95% CI 25% to 36%).

CONCLUSIONS

Stent retriever thrombectomy is a safe treatment modality for patients with stroke presenting with BAO. Although the stent retrievers showed a good recanalisation rate, there are currently no randomised clinical trials to assess its clinical efficacy in comparison with the reference treatment.

"Missing clot" during mechanical thrombectomy in acute stroke using Solitaire stent retrieval system

Stent retrieval system is an established treatment modality in acute ischemic stroke with large vessel occlusion. Here, we describe a complication which occurred during mechanical thrombectomy in three cases where the clot dislodged during retrieval. There was a possibility of the clot getting reinjected into the artery with possible dire consequences.

Clinical and radiological outcome after mechanical thrombectomy in acute ischemic stroke: What matters?

OBJECTIVE

Recent studies have shown the efficacy of mechanical thrombectomy in acute ischemic stroke. We sought to identify prognostic parameters for clinical and radiological outcome after mechanical thrombectomy.

METHODS

In 34 patients (age 72 ± 13 years, 64.7% women) with acute occlusion of the distal ICA and/or M1 segment who were treated with mechanical thrombectomy, the Spearman correlation was performed to assess potential prognostic outcome parameters (age, NIHSS, ASPECT, thrombus length (TL), clot burden score (CBS), relative filling time delay (rFTD), time to recanalization (TTR) and TICI score). The modified Rankin scale (mRS) and the Alberta Stroke Program Early CT (ASPECT) score were used for clinical and radiological outcome, respectively. Receiver operating characteristic (ROC) analysis was performed to assess parameters predicting favorable clinical (ΔmRS ≤ 2) and radiological outcome (ΔASPECT ≤ 2).

RESULTS

Variables associated with favorable clinical outcome included NIHSS, TL, TTR and TICI score (p ≤ 0.01) with NIHSS ≤ 15 (p = 0.001, area under the curve (AUC) 0.87), TL ≤ 2 cm (p = 0.017, AUC 0.75), TTR ≤ 231 min (p = 0.001 AUC 0.88) and TICI ≥ 2b (p = 0.050, AUC 0.70). Shorter TTR and higher TICI scores were associated with favorable radiological outcome (p < 0.001) with TTR ≤ 224 min (p = 0.023, AUC 0.77) and TICI ≥ 2b (p = 0.000, AUC 0.86).

CONCLUSION

Fast and complete recanalization is essential to achieve a favorable radiological and functional outcome after mechanical thrombectomy in acute ischemic stroke. Age, CBS and collateral supply play a subordinate role.

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.

Stent Retriever-Assisted Mechanical Thrombectomy for Acute Basilar Artery Occlusion: Single US Institution Experience

BACKGROUND

Acute basilar artery occlusion causes devastating strokes that carry high mortality and morbidity.

OBJECTIVE

To report the outcomes of mechanical thrombectomy in the posterior circulation with a focus on safety and efficacy of stent retrievers.

METHODS

We retrospectively reviewed our endovascular database for all patients treated with stent retrievers for posterior circulation stroke between June 2012 and June 2014. Twelve patients were identified. The following data were analyzed: thrombus location, previous stroke or transient ischemic attack, thrombus etiology, comorbidities, time from presentation to initiation of endovascular treatment, time from start of angiography to revascularization, and whether intravenous tissue plasminogen activator was administered pre-thrombectomy. Outcome was considered poor when modified Rankin Scale score was &gt;2.

RESULTS

Mean patient age was 63.42 years (median, 64.5; range, 28-83 years); 7 were women. Successful recanalization (Thrombolysis in Cerebral Infarction grade 2b or 3) was achieved in 11 of 12 patients (91.7%). Mean discharge modified Rankin Scale score was 2.3 (median, 2.0; standard deviation 1.96; range, 0-6), with a favorable discharge outcome in 9 of 12 (75%) patients. Two patients died as inpatients. Mean follow-up modified Rankin Scale score was 1.4 (median, 1.00; standard deviation 1.075; range, 0-4). Good outcome was achieved in 9 of 10 (90%) patients at last follow-up (mean follow-up duration, 132.42 days [median, 90.50; standard deviation 80.2; range, 8-378 days]).

CONCLUSION

Our single-institution study has shown that good clinical outcomes and successful recanalization with acceptable mortality can be achieved with current stent retrievers.

Outcomes of endovascular treatment of basilar artery occlusion in the stent retriever era: a systematic review and meta-analysis

Background

Stent retriever thrombectomy has recently been found to be effective for anterior circulation strokes, but its efficacy for basilar artery occlusion (BAO) is unclear.

Objective

To carry out a systematic review and meta-analysis to analyze the available evidence for the use of stent retrievers for BAO.

Methods

Two independent reviewers searched six databases for studies reporting outcomes following endovascular treatment for BAO.

Results

A total of 17 articles (6 prospective and 11 retrospective) were included. The weighted mean age of patients was 67 years (range 59–82) and 59% were male. Thrombolytic drugs were administered intravenously and intra-arterially in 46% (range 0–88%) and 38% (range 0–90%) of patients, respectively. Weighted pooled estimates of successful recanalization (TICI 2b–3) and good outcome (modified Rankin Scale ≤2) were 80.0% (95% CI 70.7% to 88.0%; I2=80.28%; p<0.001) and 42.8% (95% CI 34.0% to 51.8%; I2=61.83%; p=0.002), respectively. Pooled mortality was 29.4% (95% CI 23.9% to 35.3%; I2=37.01%; p=0.087). Incidence of procedure-related complications and symptomatic hemorrhage was 10.0% (95% CI 3.7% to 18.3%; I2=61.05%; p=0.017) and 6.8% (95% CI 3.5% to 10.8%; I2=37.99%; p=0.08), respectively.

Conclusions

Stent retriever thrombectomy achieves a high rate of recanalization and functional independence while being relatively safe for patients with BAO. Future prospective studies with long-term follow-up are warranted.

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.

Patterns and Clinical Impact of Angiographically Visible Distal Emboli During Thrombectomy With Solitaire for Acute Ischemic Stroke

BACKGROUND:

Revascularization rates with stent retrievers after acute ischemic stroke are 69% to 86%, but favorable clinical outcomes occur in just 43% to 58% of cases. New distal emboli may negatively impact clinical outcomes.

OBJECTIVE:

To determine the prevalence and angiographic pattern of distal emboli associated with mechanical thrombectomy using the Solitaire Flow Restoration device and evaluate their correlation with clinical outcome.

METHODS:

We retrospectively reviewed the cerebral angiography of all patients with acute ischemic stroke who underwent mechanical thrombectomy with the use of the Solitaire FR device from 2012 to 2013. Angiographic microcatheter runs prior to Solitaire deployment and after thrombectomy were compared to identify new distal filling defects. Clinical outcome was assessed at discharge and after 90 days.

RESULTS:

Successful revascularization using the Solitaire device occurred in 36 of 39 patients (92%). Three distinct patterns were identified: new distal emboli in the same vascular territory (n = 3), new distal emboli in a new vascular territory (n = 3), and distal emboli that resolved after proximal revascularization (n = 7). Thirteen patients had distal emboli before and after Solitaire runs, and 13 showed no evidence of distal emboli. Favorable outcome (modified Rankin scores 0-2) was seen in 54% of all patients and 83% of patients with new distal emboli; thus, there was no correlation between new emboli and unfavorable clinical outcome (P = .67).

CONCLUSION:

We report an incidence rate of at least 15% of new emboli associated with use of the Solitaire device during thrombectomy in our series. Filling defects after Solitaire use were not associated with poor outcomes at discharge or 90-day follow-up.

Inadvertent Stent Retriever Detachment: A Multicenter Case Series and Review of Device Experience FDA Reports

Mechanical thrombectomy using retrievable stents or stent retriever devices has become the mainstay of intra-arterial therapy for acute ischemic stroke. The recent publication of a series of positive trials supporting intra-arterial therapy as standard of care for the treatment of large vessel occlusion will likely further increase stent retriever use. Rarely, premature stent detachment during thrombectomy may be encountered. In our multicenter case series, we found a rate of detachment of less than 1% (n = 7/1,067), and all were first-generation Solitaire FR devices. A review of the US Food and Drug Administration database of device experience yielded 90 individual adverse reports of detachment. There were 82, 1 and 7 detachments of Solitaire FR (first generation), Solitaire FR2 (second generation) and Trevo devices, respectively. We conclude with a brief overview of the technical and procedural considerations which may be helpful in avoiding this rare complication.

Mechanical Thrombectomy of Distal Occlusions in the Anterior Cerebral Artery: Recanalization Rates, Periprocedural Complications, and Clinical Outcome

BACKGROUND AND PURPOSE

Patients with acute ischemic stroke in the anterior circulation are at risk for either primary or, following mechanical thrombectomy, secondary occlusion of the anterior cerebral artery. Because previous studies had only a limited informative value, we report our data concerning the frequency and location of distal anterior cerebral artery occlusions, recanalization rates, periprocedural complications, and clinical outcome.

MATERIALS AND METHODS

We performed a retrospective analysis of prospectively collected data of patients with acute ischemic stroke undergoing mechanical thrombectomy in the anterior circulation between June 2010 and April 2015.

RESULTS

Of 368 patients included in this analysis, we identified 30 (8.1%) with either primary (n = 17, 4.6%) or secondary (n = 13, 3.5%) embolic occlusion of the distal anterior cerebral artery. The recanalization rate after placement of a stent retriever was 88%. Periprocedural complications were rare and included vasospasms (n = 3, 10%) and dissection (n = 1, 3.3%). However, 16 (53.5%) patients sustained an (at least partial) infarction of the anterior cerebral artery territory. Ninety days after the ictus, clinical outcome according to the modified Rankin Scale score was the following: 0-2, n = 11 (36.6%); 3-4, n = 9 (30%); 5-6, n = 10 (33.3%).

CONCLUSIONS

Occlusions of the distal anterior cerebral artery affect approximately 8% of patients with acute ischemic stroke in the anterior circulation receiving mechanical thrombectomy. Despite a high recanalization rate and a low complication rate, subsequent (partial) infarction in the anterior cerebral artery territory occurs in approximately half of patients. Fortunately, clinical outcome appears not to be predominately unfavorable.

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.

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.

Endovascular Treatment of Acute Stroke: Evolution and Selection of Techniques and Instruments Based on Thrombus Imaging

Mechanical thrombectomy provides higher recanalization rates than intravenous or intra-arterial thrombolysis. Finally this has been shown to translate into improved clinical outcome in six multicentric randomized controlled trials. However, within cohorts the clinical outcomes may vary, depending on the endovascular techniques applied. Systems aiming mainly for thrombus fragmentation and lacking a protection against distal embolization have shown disappointing results when compared to recent stent-retriever studies or even to historical data on local arterial fibrinolysis. Procedure-related embolic events are usually graded as adverse events in interventional neuroradiology. In stroke, however, the clinical consequences of secondary emboli have so far mostly been neglected and attributed to progression of the stroke itself. We summarize the evolution of instruments and techniques for endovascular, image-guided, microneurosurgical recanalization in acute stroke, and discuss how to avoid procedure-related embolic complications.

2015 American Heart Association/American Stroke Association Focused Update of the 2013 Guidelines for the Early Management of Patients With Acute Ischemic Stroke Regarding Endovascular Treatment: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

PURPOSE

The aim of this guideline is to provide a focused update of the current recommendations for the endovascular treatment of acute ischemic stroke. When there is overlap, the recommendations made here supersede those of previous guidelines.

METHODS

This focused update analyzes results from 8 randomized, clinical trials of endovascular treatment and other relevant data published since 2013. It is not intended to be a complete literature review from the date of the previous guideline publication but rather to include pivotal new evidence that justifies changes in current recommendations. Members of the writing committee were appointed by the American Heart Association/American Stroke Association Stroke Council's Scientific Statement Oversight Committee and the American Heart Association/American Stroke Association Manuscript Oversight Committee. Strict adherence to the American Heart Association conflict of interest policy was maintained throughout the consensus process. Recommendations follow the American Heart Association/American Stroke Association methods of classifying the level of certainty of the treatment effect and the class of evidence. Prerelease review of the draft guideline was performed by 6 expert peer reviewers and by the members of the Stroke Council Scientific Statement Oversight Committee and Stroke Council Leadership Committee.

RESULTS

Evidence-based guidelines are presented for the selection of patients with acute ischemic stroke for endovascular treatment, for the endovascular procedure, and for systems of care to facilitate endovascular treatment.

CONCLUSIONS

Certain endovascular procedures have been demonstrated to provide clinical benefit in selected patients with acute ischemic stroke. Systems of care should be organized to facilitate the delivery of this care.

Endovascular Recanalization in Acute Ischemic Stroke Using the Solitaire FR Revascularization Device with Adjunctive C-Arm CT Imaging

In this clinical report, we examined a single-center experience by using the Solitaire FR Revascularization Device in the treatment of acute ischemic stroke in which there was poor initial visualization of the occluded arterial branches by using biplanar cerebral angiography. In all cases, adjunctive C-arm CT was used during the deployment of the thrombectomy device to gain additional information regarding device placement and expansion. Outcome measures included the extent of reperfusion, posttreatment changes in NIHSS scores, posttreatment TICI scores, cerebral hemorrhage, and survival. Clot removal with successful arterial recanalization was achieved in 15/18 cases (83.3%) with TICI scores of 2b/3 in all patients who had initial recanalization. The NIHSS score improved, on average, from 19 pretreatment to 11 posttreatment, and 72% of patients survived. In cases of acute stroke in which there is little information available regarding the positioning and deployment of a retrievable stent during mechanical thrombectomy, the use of C-arm CT may provide more information about device placement across an area of thrombus.

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.

Prior IV Thrombolysis Facilitates Mechanical Thrombectomy in Acute Ischemic Stroke

BACKGROUND

In acute ischemic stroke (AIS), bridging therapy, including intravenous thrombolysis (IVT) and mechanical thrombectomy (MET), appears to be very promising. However, data on the impact of IVT before the endovascular procedure are limited.

METHODS

To examine the impact of IVT on the MET procedure, we compared the duration of this procedure, number of passes, recanalization rate, safety issues, and outcome in consecutively recruited patients either eligible for MET alone (intravenous fibrinolysis contraindication) or receiving MET preceded by IVT for proximal middle cerebral artery (MCA) occlusion within 6 hours of stroke onset.

RESULTS

From January 2011 to June 2013, 68 cases with proximal MCA occlusion were available for analysis (MET alone, 40; IVT + MET, 28). The 2 groups did not differ significantly in baseline characteristics. The median National Institutes of Health Stroke Scale score at admission was 15 (10-20) for MET and 18 (13-19) for IVT + MET groups, respectively (P = .39). The median duration of the endovascular procedure (from groin puncture to recanalization) was significantly shorter in the IVT + MET group compared with that in MET alone (35 minutes [21-60] versus 60 minutes [25-91]; P = .043). The number of passes of the thrombectomy device per patient tended to be lower in the IVT + MET group than those in the MET group (P = .080). The IVT + MET group also had a higher rate of complete recanalization and a better outcome at 3 months.

CONCLUSIONS

Prior IVT may facilitate the MET procedure. Further studies on MET in AIS should assess the direct impact of IVT on the endovascular procedure.

Stent retriever thrombectomy with the Cover accessory device versus proximal protection with a balloon guide catheter: in vitro stroke model comparison

Background

Recently, an in vitro cerebrovascular occlusion model of the intracranial circulation was developed for testing thrombectomy devices. The Cover accessory (Lazarus Effect; Campbell, California, USA) is a novel nitinol braided mesh device that surrounds the stent retrieval device and thrombus during the retrieval process to help prevent clot fragmentation and embolization.

Methods

Using the in vitro model, after introducing fresh clot into the middle cerebral artery, we compared rates of target vessel recanalization and embolization in new territories (areas in which clot had not been introduced) achieved with the Solitaire Flow Restoration (FR) stent retriever (Covidien, Irvine, California) in conjunction with the use of a conventional guide catheter (control group), a balloon guide catheter (BGC group), and the Cover device (Cover group).

Results

In a total of 51 thrombectomy experiments (20 in the control group, 20 in the BGC group, and 11 in the Cover group), successful recanalization (Thrombolysis in Cerebral Infarction 2b–3) was achieved more frequently in the Cover group than in the control group or in the BGC group (p=0.047 and p=0.020, respectively). Embolization of new (previously unaffected) territories occurred in five (25%) experiments from the control group and in three (15%) experiments from the BGC group, whereas no embolization of new territories was seen with Cover device assisted thrombectomy.

Conclusions

Application of the Cover device in this experimental model resulted in higher successful recanalization rates, no embolic events, and was more effective than use of the conventional guide catheter or BGC.