Mechanical thrombectomy in acute ischemic stroke: catch device

Mechanical thrombectomy in anterior vs. posterior circulation stroke: A systematic review and meta-analysis

BACKGROUND

High-quality evidence exists for mechanical thrombectomy (MT) treatment of acute ischemic stroke (AIS) due to large vessel occlusion of the anterior circulation (AC-LVO). The evidence for MT treatment of posterior circulation large vessel occlusion (PC-LVO) is weaker, largely drawn from lower quality studies specific to PC-LVO and extrapolated from findings in AC-LVO, and ambiguous with regards to technical success. We performed a systematic review and meta-analysis to compare the technical success and functional outcomes of MT in PC-LVO versus AC-LVO patients.

METHODS

We identified comparative studies reporting on patients treated with MT in AC-LVO versus PC-LVO. The primary outcome of interest was thrombolysis in cerebral infarction (TICI) ≥ 2b. Secondary outcomes included rates of TICI 3, 90-day functional independence, first-pass-effect, average number of passes, and 90-day mortality. A separate random effects model was fit for each outcome measure.

RESULTS

Twenty studies with 12,911 patients, 11,299 (87.5%) in the AC-LVO arm and 1612 (12.5%) in the PC-LVO arm, were included. AC-LVO and PC-LVO patients had comparable rates of successful recanalization [OR = 1.02 [95% CI: 0.79-1.33], p = 0.848). However, the AC-LVO group had greater odds of 90-day functional independence (OR = 1.26 [95% CI: 1.00; 1.59], p = 0.050) and lower odds of 90-day mortality (OR = 0.58 [95% CI: 0.43; 0.79], p = 0.002).

CONCLUSIONS

MT achieves similar rates of recanalization with a similar safety profile in PC-LVO and AC-LVO patients. Patients with PC-LVO are less likely to achieve functional independence after MT. Future studies should identify PC-LVO patients who are likely to achieve favourable functional outcomes.

Comparison of Risk Factors, Safety, and Efficacy Outcomes of Mechanical Thrombectomy in Posterior vs. Anterior Circulation Large Vessel Occlusion

Background and Purpose: It is believed that stroke occurring due to posterior circulation large vessel occlusion (PCLVO) and that occurring due to anterior circulation large vessel occlusion (ACLVO) differ in terms of their pathophysiology and the outcome of their acute management in relation to endovascular mechanical thrombectomy (MT). Limited sample size and few randomized controlled trials (RCTs) with respect to PCLVO make the safety and efficacy of MT, which has been confirmed in ACLVO, difficult to assess in the posterior circulation. We therefore conducted a meta-analysis to study to which extent MT in PCLVO differs from ACLVO. Materials and Methods: We searched the databases PubMed, Cochrane, and EMBASE for studies published between 2010 and January 2021, with information on risk factors, safety, and efficacy outcomes of MT in PCLVO vs. ACLVO and conducted a systematic review and meta-analysis; we compared baseline characteristics, reperfusion treatment profiles [including rates of intravenous thrombolysis (IVT) and onset-to-IVT and onset-to-groin puncture times], recanalization success [Thrombolysis In Cerebral Infarction scale (TICI) 2b/3], symptomatic intracranial hemorrhage (sICH), and favorable functional outcome [modified Rankin Score (mRS) 0-2] and mortality at 90 days. Results: Sixteen studies with MT PCLVO (1,172 patients) and ACLVO (7,726 patients) were obtained from the search. The pooled estimates showed higher baseline National Institutes of Health Stroke Scale (NIHSS) score (SMD 0.32, 95% CI 0.15-0.48) in the PCLVO group. PCLVO patients received less often IVT (OR 0.65, 95% CI 0.53-0.79). Onset-to-IVT time (SMD 0.86, 95% CI 0.45-1.26) and onset-to-groin puncture time (SMD 0.59, 95% CI 0.33-0.85) were longer in the PCLVO group. The likelihood of obtaining successful recanalization and favorable functional outcome at 90 days was comparable between the two groups. PCLVO was, however, associated with less sICH (OR 0.56, 95% CI 0.37-0.85) but higher mortality (OR 1.92, 95% CI 1.46-2.53). Conclusions: This meta-analysis indicates that MT in PCLVO may be comparably efficient in obtaining successful recanalization and 90 day favorable functional outcome just as in ACLVO. Less sICH in MT-treated PCLVO patients might be the result of the lower IVT rate in this group. Higher baseline NIHSS and longer onset-to-IVT and onset-to-groin puncture times may have contributed to a higher 90 day mortality in PCLVO patients.

Simplified selection criteria for patients with longer or unknown time to treatment predict good outcome after mechanical thrombectomy

Objective

To identify simplified selection criteria for mechanical thrombectomy (MT) in longer and unknown time windows.

Methods

Patients with large vessel occlusion (LVO) in the anterior circulation who underwent MT between January 2014 and November 2017 were identified from the local registry. Patients were selected for analysis if they met the current guideline recommendation for MT treatment except for time window (HERMES-like) and were divided according to time they were last seen well (LSW): LSW <6 hours or LSW >6 hours before MT. The primary endpoint, good outcome, was modified Rankin scale score 0–2 on day 90. Safety outcomes were mortality on day 90 and symptomatic intracranial hemorrhage (sICH). Univariate and multivariate analysis were performed for good outcome in HERMES-like patients.

Results

In total, 752 patients were identified and 390 patients (51.9%) fulfilled the HERMES-like criteria. Despite differences in baseline parameters, more diffusion-weighted imaging (DWI) (43.9% vs 11.3%, p<0.001) and fewer cases of thrombolysis (32.7% vs 77%, p<0.001), patients LSW >6 hours (n=107) did not differ in the primary and secondary endpoints: good outcome (44.9% vs 44.9%, p=1.0), mortality (14% vs 15.2%, p=0.87), and sICH (5.6% vs 6%, p=1.0). After multivariate regression analysis, independent predictors of good outcome remained: age, OR=0.96 (95% CI 0.95 to 0.98); National Institutes of Health Stroke Scale score, OR=0.92 (95% CI 0.89 to 0.96); Alberta Stroke Programme Early CT Score (ASPECTS), OR=1.26 (95% CI 1.06 to 1.49); general anesthesia, OR=0.2 (95% CI 0.04 to 0.99), and successful recanalization, OR=12 (95% CI 4.7 to 30.5); but not treatment time and DWI or CT perfusion at baseline.

Conclusion

Patients with proven LVO in unknown and longer time windows may be selected for MT based on ASPECTS and clinical criteria.

Mechanical Thrombectomy: Emerging Technologies and Techniques

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Reperfusion therapy in acute ischemic stroke: dawn of a new era?

Following the success of recent endovascular trials, endovascular therapy has emerged as an exciting addition to the arsenal of clinical management of patients with acute ischemic stroke (AIS). In this paper, we present an extensive overview of intravenous and endovascular reperfusion strategies, recent advances in AIS neurointervention, limitations of various treatment paradigms, and provide insights on imaging-guided reperfusion therapies. A roadmap for imaging guided reperfusion treatment workflow in AIS is also proposed. Both systemic thrombolysis and endovascular treatment have been incorporated into the standard of care in stroke therapy. Further research on advanced imaging-based approaches to select appropriate patients, may widen the time-window for patient selection and would contribute immensely to early thrombolytic strategies, better recanalization rates, and improved clinical outcomes.

Catch Plus thrombectomy device in acute stroke: initial evaluation

OBJECTIVE

To report our initial experience with the Catch Plus thrombectomy device (CPD) in patients with acute ischemic stroke (AIS).

MATERIALS AND METHODS

We retrospectively evaluated the procedural variables as well as the clinical and angiographic outcomes of patients with acute occlusion of a major intracranial artery in the anterior circulation who were treated with CPD at our center. Baseline characteristics (gender, age, comorbidities, cardiovascular risk factors, National Institutes of Health Stroke Scale (NIHSS) score, and vessel occlusion sites) of these patients were recorded. Thrombolysis in Cerebral Infarction (TICI) score, incidence of symptomatic and asymptomatic bleeding, and 90 day modified Rankin Scale (mRS) scores were evaluated as indicators of outcome.

RESULTS

38 patients with a mean age of 67.5 years were treated with CPD. Mean time from symptom onset to procedure initiation was 226.7 min. Recanalization (TICI 2b-3) was achieved in 27 patients (71.1%). The median NIHSS score on admission was 20. Rates of symptomatic and asymptomatic intracerebral hemorrhage were 7.9% and 13.2%, respectively. The 90 day clinical follow-up data were available for 37 patients. The 90 day mortality rate was 18.9%, and the 90 day clinically acceptable functional outcome (mRS score ≤2) rate was 43.2% (mRS score 0-3, 54.1%). Very distal thrombectomy involving the cortical arteries was performed on four patients without complications.

CONCLUSIONS

Our initial experience suggests that mechanical thrombectomy with the CPD improves 90 day outcomes of patients with AIS by facilitating effective recanalization.

[Technical standards for the interventional treatment of acute ischemic stroke]

Acute ischemic stroke is the leading cause of acquired disability and its treatment is still a major challenge. For more than a decade, various mechanical devices have been developed for the recanalization of proximal artery occlusions in acute ischemic stroke but most of them have been approved for clinical use, only on the basis of uncontrolled case series. Intravenous thrombolysis with recombinant tissue-specific plasminogen activator administered (iv rtPA) within 4.5 h of symptom onset is so far the only approved medicinal treatment in the acute phase of cerebral infarction. With the introduction of stent retrievers, mechanical thrombectomy has demonstrated substantial rates of partial or complete arterial recanalization and improved outcomes compared with iv rtPA and best medical treatment alone in multiple randomized clinical trials in select patients with acute ischemic stroke and proximal artery occlusions. This review discusses the evolution of endovascular stroke therapy followed by a discussion of the current technical standards of mechanical thrombectomy that have to be considered during endovascular stroke therapy and the updated treatment recommendations of the ESO Karolinska stroke update.

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

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

Inter- and intraobserver agreement in scoring angiographic results of intra-arterial stroke therapy

BACKGROUND AND PURPOSE

Angiographic results are commonly used as surrogate markers of the success of intra-arterial therapies for acute stroke. Inter- and intraobserver agreement in judging angiographic results remain poorly characterized. Our goal was to assess 2 commonly used revascularization scales.

MATERIALS AND METHODS

A portfolio of 148 pre- and post treatment images of 37 cases of proximal anterior circulation occlusions was electronically sent to 12 expert observers who were asked to grade treatment outcomes according to recanalization (of arterial occlusive lesion) or reperfusion (TICI) scales. Three expert observers had to score treatment outcomes by using a similar portfolio of 32 patients or when they had full access to all angiographic data, twice for each method 3-12 months apart. Results were analyzed by using κ statistics.

RESULTS

Agreement among 9 responding observers was moderate for both the TICI (κ = 0.45 ± 0.01) and arterial occlusive lesion (κ = 0.39 ± 0.16) scales. Agreement was similar (moderate) when 3 observers had access to a portfolio (κ = 0.59 ± 0.06 and 0.49 ± 0.07, respectively) or to the full angiographic data (κ = 0.54 ± 0.06 and 0.59 ± 0.07, respectively). Intraobserver agreement was "fair to moderate" for both methods. Interobserver agreement became "substantial" (>0.6) when outcomes were dichotomized into "success" (TICI 2b, 3; arterial occlusive lesion II, III or "failure"; the results were judged more favorably when the arterial occlusive lesion rather than the TICI scale was used.

CONCLUSIONS

There is an important variability in the assessment of angiographic outcomes of endovascular treatments, invalidating comparisons among publications. A simple dichotomous judgment can be used as a surrogate outcome when treatments are assessed by the same observers in randomized trials.

Safety and efficacy of endovascular sonolysis using the EkoSonic endovascular system in patients with acute stroke

BACKGROUND AND PURPOSE

Sonolysis is a new therapeutic procedure for arterial recanalization. The aim of this study was to confirm the safety and efficacy of endovascular sonolysis by using the EkoSonic Endovascular System in subjects with acute ischemic stroke.

MATERIALS AND METHODS

Patients with acute ischemic stroke with occlusion of the middle cerebral artery or basilar artery were enrolled consecutively in this prospective study. The control group (44 MCA and 12 BA occlusions) was selected from historical controls. EkoSonic Endovascular System was started within 8 hours after stroke onset. The NIHSS score at hospital admission, after 24 hours, and at 7 days; arterial recanalization; early neurologic improvement; symptomatic intracerebral hemorrhage; and favorable 3-month clinical outcome defined as a modified Rankin Scale score of 0-2 were evaluated by statistical means.

RESULTS

Fourteen patients (10 men; mean age, 65.1 ± 11.2 years; median NIHSS score, 16.5) underwent EkoSonic endovascular sonolysis. Arterial recanalization after endovascular treatment was achieved in 6 of 7 (85.7%) patients with MCA occlusion (4 complete recanalizations) and in all 7 (100%) patients with BA occlusion (6 complete recanalizations). No (0%) symptomatic intracerebral hemorrhage or periprocedural complications occurred. Seven (50%) patients were independent at 3 months (median mRS score, 2). Early neurologic improvement and favorable clinical outcome were significantly more frequent in patients with MCA occlusion undergoing EkoSonic endovascular sonolysis than in controls (100% and 71.4% versus 4.6% and 13.6% of patients; P = .0001 and P = .003, respectively). Three-month mortality was significantly lower in patients with BA occlusion undergoing EkoSonic endovascular sonolysis than in controls (0% versus 66.7% patients, P = .013).

CONCLUSIONS

In this small study, EkoSonic endovascular sonolysis allowed safe and potentially effective revascularization in patients experiencing acute ischemic stroke.

The quest for arterial recanalization in acute ischemic stroke-the past, present and the future

Ischemic stroke is one of the major causes of mortality and long-term disability. In the recent past, only very few treatment options were available and a considerable proportion of stroke survivors remained permanently disabled. However, over the last 2 decades rapid advances in acute stroke care have resulted in a corresponding improvement in mortality rates and functional outcomes. In this review, we describe the evolution of systemic thrombolytic agents and various interventional devices, their current status as well as some of the future prospects. We reviewed literature pertaining to acute ischemic stroke reperfusion treatment. We explored the current accepted treatment strategies to attain cerebral reperfusion via intravenous modalities and compare and contrast them within the boundaries of their clinical trials. Subsequently we reviewed the trials for interventional devices for acute ischemic stroke, categorizing them into thrombectomy devices, aspiration devices, clot disruption devices and thrombus entrapment devices. Finally we surveyed several of the alternative reperfusion strategies available. We also shed some light on the controversies surrounding the current strategies of treatment of acute ischemic stroke. Acute invasive interventional strategies continue to improve along with the noninvasive modalities. Both approaches appear promising. We conducted a comprehensive chronological review of the existing treatments as well as upcoming remedies for acute ischemic stroke.

Does mechanical thrombectomy in acute embolic stroke have long-term side effects on intracranial vessels? An angiographic follow-up study

PURPOSE

Mechanical thrombectomy (mTE) proved to be effective treating acute vessel occlusions with an acceptable rate of procedural complications. Potential long-term side effects of the vessel wall trauma caused by mechanical irritation of the endothelium are unknown up to now.

METHODS

From a retrospectively established database of 640 acute stroke treatments, we selected 261 patients with 265 embolic vessel occlusions treated successfully by mTE without permanent implantation of a stent. Analysis comprised the type of devices used and the number of passes performed. Digital subtraction angiography immediately after treatment was evaluated for vasospasm, dissection, and extravasation. Control angiographic images were evaluated for any morphological change compared to the immediate posttreatment angiographic run.

RESULTS

Recanalization was achieved with a median of one (range 1-10) mTE maneuvers. Vasospasm occurred in 69 territories (26.0 %) and was treated with glyceroltrinitrate in three. Dissection was observed in one vessel (0.4 %). Intraprocedural hemorrhage in two patients (0.8 %) was either wire or device induced. Follow-up digital subtraction angiography was available for 117 territories after a median of 107 days, revealing target vessel occlusion in one segment (0.9 %) and a de novo stenosis of four segments (3.4 %). All findings were clinically asymptomatic. Posttreatment vasospasm was more frequent in patients with de novo stenosis and occlusion (p = 0.038).

CONCLUSION

De novo stenoses and occlusions occur in a small proportion of patients after mTE. Because all lesions were clinically asymptomatic, this finding does not affect the overall benefit of the treatment. Vasospasm may predict late vessel wall changes.

Beyond the time window of intravenous thrombolysis: standing by or by stenting?

Intravenous administration of tissue plasminogen activator within 4.5 h of symptom onset is presently the 'golden rule' for treating acute ischemic stroke. However, many patients miss the time window and others reject this treatment due to a long list of contraindications. Mechanical embolectomy has recently progressed as a potential alternative for treating patients beyond the time window for IV thrombolysis. In this paper, recent progress in mechanical embolectomy, angioplasty, and stenting in acute stroke is reviewed. Despite worries concerning the long-term clinical outcomes and increased risk of intracranial hemorrhage, favorable clinical outcomes may be achieved after mechanical embolectomy in carefully selected patients even 4.5 h after stroke onset. Potential steps should be prepared and attempted in these patients whose opportunity for recovery will elapse in a flash.