Rescue Stenting for Failed Mechanical Thrombectomy in Acute Ischemic Stroke: A Multicenter Experience

The Safety of Intra-arterial Tirofiban during Endovascular Therapy after Intravenous Thrombolysis

BACKGROUND AND PURPOSE

The safety and efficacy of tirofiban during endovascular therapy in patients undergoing intravenous thrombolysis with recombinant IV tPA remain unclear. This study aimed to investigate the safety and efficacy of intra-arterial tirofiban use during endovascular therapy in patients treated with IV tPA.

MATERIALS AND METHODS

Using a multicenter registry, we enrolled patients with acute ischemic stroke who underwent endovascular therapy. Safety outcomes included postprocedural parenchymal hematoma type 2 and/or thick subarachnoid hemorrhage, intraventricular hemorrhage, and 3-month mortality. Efficacy outcomes included the successful reperfusion rate, postprocedural reocclusion, and good outcomes at 3 months (mRS scores of 0-2). The tirofiban effect on the outcomes was evaluated using a multivariable analysis while adjusting for potential confounders.

RESULTS

Among enrolled patients, we identified 314 patients with stroke (279 and 35 patients in the no tirofiban and tirofiban groups, respectively) due to an intracranial artery occlusion who underwent endovascular therapy with intravenous thrombolysis. A multivariable analysis revealed no association of intra-arterial tirofiban with postprocedural parenchymal hematoma type and/or thick subarachnoid hemorrhage (adjusted OR, 1.07; 95% CI, 0.20-4.10; P = .918), intraventricular hemorrhage (adjusted OR, 0.43; 95% CI, 0.02-2.85; P = .467), and 3-month mortality (adjusted OR, 0.38; 95% CI, 0.04-1.87; P = .299). Intra-arterial tirofiban was not associated with good outcome (adjusted OR, 2.22; 95% CI, 0.89 -6.12; P = .099).

CONCLUSIONS

Using intra-arterial tirofiban during endovascular therapy after IV tPA could be safe.

Efficacy of Solitaire AB stent-release angioplasty in acute middle cerebral artery atherosclerosis obliterative cerebral infarction

BACKGROUND

In both national and international studies, the safety and effectiveness of treatment with the Solitaire stent in patients with ischemic stroke caused by acute large vessel occlusion were good, and the disability rate was significantly reduced. However, there are currently only a few reports on the differences in endovascular treatment for different etiological classifications, especially in the anterior cranial circulation, aorta atherosclerotic stenosis, and acute thrombosis.

AIM

To investigate the efficacy of Solitaire AB stent-release angioplasty in patients with acute middle cerebral artery atherosclerosis obliterative cerebral infarction.

METHODS

Twenty-five patients with acute middle cerebral atherosclerosis obliterative cerebral infarction were retrospectively enrolled in this study from January 2017 to December 2019. The Solitaire AB stent was used to improve anterior blood flow to maintain modified cerebral infarction thrombolysis [modified thrombolysis in cerebral infarction (mTICI)] at the 2b/3 level or above, the stent was then unfolded and released.

RESULTS

All 25 patients underwent successful surgery, with an average recanalization time of 23 min. One patient died of cerebral hemorrhage and cerebral herniation after the operation. The National Institutes of Health Stroke Scale (NIHSS) scores immediately after surgery (7.5 ± 5.6), at 24 h (5.5 ± 5.6) and at 1 wk (3.6 ± 6.7) compared with the preoperative NIHSS score (15.9 ± 4.4), were significantly different (P < 0.01). One case of restenosis was observed 3 mo after surgery (the stenosis rate was 50% without clinical symptoms), the modified Rankin scale scores were 0 points in 14 cases (56%), 1 point in 4 cases (16%), 2 points in 2 cases (8%), 3 points in 3 cases (12%), 4 points in 1 case (4%), and 6 points in 1 case (4%).

CONCLUSION

In acute middle cerebral artery atherosclerosis obliterative cerebral infarction, when the Solitaire AB stent is unfolded and the forward blood flow is maintained at mTICI level 2b/3 or higher, stent release may be a safe and effective treatment method; however, long-term observation and a larger sample size are required to verify these findings.

Combination of Rescue Stenting and Antiplatelet Infusion Improved Outcomes for Acute Intracranial Atherosclerosis-Related Large-Vessel Occlusion

Background and Purpose: Intracranial atherosclerosis-related large-vessel occlusion caused by in situ thrombo-occlusion (ICAS-LVO) has been regarded an important reason for refractoriness to mechanical thrombectomy (MT). To achieve better outcomes for ICAS-LVO, different endovascular strategies should be explored. We aimed to investigate an optimal endovascular strategy for ICAS-LVO.

Methods: We retrospectively reviewed three prospective registries of acute stroke underwent endovascular treatment. Among them, patients with ICAS-LVO were assigned to four groups based on their endovascular strategy: (1) MT alone, (2) rescue intracranial stenting after MT failure (MT-RS), (3) glycoprotein IIb/IIIa inhibitor infusion after MT failure (MT-GPI), and (4) a combination of MT-RS and MT-GPI (MT-RS+GPI). Baseline characteristics and outcomes were compared among the groups. To evaluate whether the endovascular strategy resulted in favorable outcome, multivariable analysis was also performed.

Results: A total of 184 patients with ICAS-LVO were included. Twenty-four patients (13.0%) were treated with MT alone, 25 (13.6%) with MT-RS, 84 (45.7%) with MT-GPI, and 51 (27.7%) with MT-RS+GPI. The MT-RS+GPI group showed the highest recanalization efficiency (98.0%). Frequency of patent arteries on follow-up (98.0%, p < 0.001) and favorable outcome (84.3%, p < 0.001) were higher in the MT-RS+GPI group than other groups. The MT-RS+GPI strategy remained an independent factor for favorable outcome (odds ratio, 20.4; 95% confidence interval, 1.97–211.4; p = 0.012).

Conclusion: Endovascular strategy was significantly associated with procedural and clinical outcomes in acute stroke by ICAS-LVO. A combination of RS and GPI infusion might be an optimal rescue modality when frontline MT fails.

Diminishing returns with successive device passes in mechanical thrombectomy for stroke

BACKGROUND

Multiple device passes are associated with complications and poor functional outcomes following mechanical thrombectomy (MT) for emergent large vessel occlusion (ELVO).

OBJECTIVE

To characterize the relationship between number of device passes, complications, angiographic outcomes, and clinical outcomes in MT for ELVO.

METHODS

This is a single-center, retrospective cohort study. Individual device passes for MT were evaluated for any change in Thrombolysis in Cerebral Infarction (TICI) score, successful revascularization (TICI 2b or 3), and complications. Outcomes were compared among groups requiring multiple passes with various cut-off points. Risk factors for unfavorable clinical outcome [90 day modified Rankin Scale > 2] were assessed using multivariate analysis.

RESULTS

Successful revascularization was achieved in 75% of 163 patients and 36% required only one device pass. After the second pass, the likelihood of angiographic improvement significantly decreased (p < 0.001). Using multiple cut-off points, higher post-procedural NIHSS scores, mortality rates, and unfavorable 90-day outcomes were associated with a greater number of passes. Multivariate analysis revealed ICA thrombus (comparison: M2, OR: 25, 95% CI 2-275, p = 0.01) and failed revascularization (OR: 68, 95% CI 3.12-1489, p = 0.01) as the only significant predictors of unfavorable clinical outcome. Nonetheless, the likelihood of favorable clinical outcome was higher in patients with an ICA occlusion who were revascularized in < 2 vs. ≥ 2 (44 vs 4%, p = 0.01) or < 3 vs. ≥ 3 (32 vs. 0%, p = 0.02) passes.

CONCLUSION

The likelihood of angiographic improvement in patients with ELVO significantly decreases after the second pass. A greater number of passes is associated with worsened clinical outcomes.

How to Improve the Management of Acute Ischemic Stroke by Modern Technologies, Artificial Intelligence, and New Treatment Methods

Stroke remains one of the leading causes of death and disability in Europe. The European Stroke Action Plan (ESAP) defines four main targets for the years 2018 to 2030. The COVID-19 pandemic forced the use of innovative technologies and created pressure to improve internet networks. Moreover, 5G internet network will be helpful for the transfer and collecting of extremely big databases. Nowadays, the speed of internet connection is a limiting factor for robotic systems, which can be controlled and commanded potentially from various places in the world. Innovative technologies can be implemented for acute stroke patient management soon. Artificial intelligence (AI) and robotics are used increasingly often without the exception of medicine. Their implementation can be achieved in every level of stroke care. In this article, all steps of stroke health care processes are discussed in terms of how to improve them (including prehospital diagnosis, consultation, transfer of the patient, diagnosis, techniques of the treatment as well as rehabilitation and usage of AI). New ethical problems have also been discovered. Everything must be aligned to the concept of “time is brain”.

Refractory Stroke Thrombectomy: Prevalence, Etiology, and Adjunctive Treatment in a North American Cohort

BACKGROUND AND PURPOSE

Acute stroke intervention refractory to mechanical thrombectomy may be due to underlying vessel wall pathology including intracranial atherosclerotic disease and intracranial arterial dissection or recalcitrant emboli. We studied the prevalence and etiology of refractory thrombectomy, the safety and efficacy of adjunctive interventions in a North American-based cohort.

MATERIALS AND METHODS

We performed a multicenter, retrospective study of refractory thrombectomy, defined as unsuccessful recanalization, vessel reocclusion in <72 hours, or required adjunctive antiplatelet glycoprotein IIb/IIIa inhibitors, intracranial angioplasty and/or stenting to achieve and maintain reperfusion. Clinical and imaging criteria differentiated etiologies for refractory thrombectomy. Baseline demographics, cerebrovascular risk factors, technical/clinical outcomes, and procedural safety/complications were compared between refractory and standard thrombectomy groups. Multivariable logistic regression analysis was performed to determine independent predictors of refractory thrombectomy.

RESULTS

Refractory thrombectomy was identified in 25/302 cases (8.3%), correlated with diabetes (44% versus 22%, P = .02) as an independent predictor with OR = 2.72 (95% CI, 1.05-7.09; P = .04) and inversely correlated with atrial fibrillation (16% versus 45.7%, P = .005). Refractory etiologies were secondary to recalcitrant emboli (20%), intracranial atherosclerotic disease (60%), and/or intracranial arterial dissection (44%). Four (16%) patients were diagnosed with early vessel reocclusion, and 21 patients underwent adjunctive salvage interventions with glycoprotein IIb/IIIa inhibitor infusion alone (32%) or intracranial angioplasty and/or stenting (52%). There were no significant differences in TICI 2b/3 reperfusion efficacy (85.7% versus 90.9%, P = .48), symptomatic intracranial hemorrhage rates (0% versus 9%, P = .24), favorable clinical outcomes (39.1% versus 48.3%, P = .51), or mortality (13% versus 28.3%, P = .14) versus standard thrombectomy.

CONCLUSIONS

Refractory stroke thrombectomy is encountered in <10% of cases, independently associated with diabetes, and related to underlying vessel wall pathology (intracranial atherosclerotic disease and/or intracranial arterial dissection) or, less commonly, recalcitrant emboli. Emergent salvage interventions with glycoprotein IIb/IIIa inhibitors or intracranial angioplasty and/or stenting are safe and effective adjunctive treatments.

Intravenous Tirofiban Infusion After Angioplasty and Stenting in Intracranial Atherosclerotic Stenosis-Related Stroke

[Figure: see text].

Factors Contributing to an Efficacious Endovascular Treatment for Acute Ischemic Stroke in Asian Population

Although randomized control trials about endovascular treatment (EVT) of emergent large vessel occlusion (LVO) have demonstrated the success of mechanical thrombectomy as the choice of treatment, a wide range of caveats remain unaddressed. Asian patients were rarely included in the trials, thereby raising the question of whether the treatment could be generalized. In addition, there remains a concern on the feasibility of the method with respect to its application against intracranial atherosclerosis (ICAS)-related LVO, frequently observed in the Asian population. It is important to include evidence on ICAS LVO from Asian countries in the future for a comprehensive understanding of LVO etiology. Besides the issues with EVT, prognostic concerns in diabetes patients, acute kidney injury following EVT, neuroprotective management against reperfusion injury, and other peri-EVT issues should be considered in clinical practice. In the current article, we present an in-depth review of the literature that revises information pertaining to such concerns.

Watershed subarachnoid hemorrhage after middle cerebral artery rescue stenting in patients with acute ischemic stroke

Cortical subarachnoid hemorrhage is an infrequent subtype of non-aneurysmal subarachnoid hemorrhage, rarely reported in watershed territories (wSAH) after carotid stenting. It has never been reported after treatment of middle cerebral artery stenosis (MCAS) that is increasingly used in selected patients, as rescue treatment of failed mechanical thrombectomy, due to recent advancements in endovascular interventions. We present a series of patients with MCAS that developed a wSAH after stenting.

Combined Use of X-ray Angiography and Intraprocedural MRI Enables Tissue-based Decision Making Regarding Revascularization during Acute Ischemic Stroke Intervention

Background For patients with acute ischemic stroke undergoing endovascular mechanical thrombectomy with x-ray angiography, the use of adjuncts to maintain vessel patency, such as stents or antiplatelet medications, can increase risk of periprocedural complications. Criteria for using these adjuncts are not well defined. Purpose To evaluate use of MRI to guide critical decision making by using a combined biplane x-ray neuroangiography 3.0-T MRI suite during acute ischemic stroke intervention. Materials and Methods This retrospective observational study evaluated consecutive patients undergoing endovascular intervention for acute ischemic stroke between July 2019 and May 2020 who underwent either angiography with MRI or angiography alone. Cerebral tissue viability was assessed by using MRI as the reference standard. For statistical analysis, Fisher exact test and Student t test were used to compare groups. Results Of 47 patients undergoing acute stroke intervention, 12 patients (median age, 69 years; interquartile range, 60-77 years; nine men) underwent x-ray angiography with MRI whereas the remaining 35 patients (median age, 80 years; interquartile range, 68-86 years; 22 men) underwent angiography alone. MRI results influenced clinical decision making in one of three ways: whether or not to perform initial or additional mechanical thrombectomy, whether or not to place an intracranial stent, and administration of antithrombotic or blood pressure medications. In this initial experience, decision making during endovascular acute stroke intervention in the combined angiography-MRI suite was better informed at MRI, such that therapy was guided in real time by the viability of the at-risk cerebral tissue. Conclusion Integrating intraprocedural 3.0-T MRI into acute ischemic stroke treatment was feasible and guided decisions of whether or not to continue thrombectomy, to place stents, or to administer antithrombotic medication or provide blood pressure medications. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Lev and Leslie-Mazwi in this issue.

Efficacy and safety of rescue angioplasty and/or stenting for acute large artery occlusion with underlying intracranial atherosclerosis: A systematic review and meta-analysis

PURPOSE

Intracranial angioplasty and/or stenting implantation is an important rescue treatment for the management of intracranial atherosclerosis-related occlusion (ICAS-O) after mechanical thrombectomy failure, but its safety and efficacy remain unclear. We investigated the safety and efficacy of rescue intracranial angioplasty and/or stenting for emergent large artery occlusion (LAO) with underlying ICAS.

METHODS

We searched for relevant full-text articles in EMBASE, PubMed and the Cochrane Central Register of Controlled Trials from inception to March 1, 2020. We calculated the odds ratios (ORs) using random-effects models for symptomatic intracranial hemorrhage (sICH), mortality, recanalization rate and favorable clinical outcome at 90 days between ICAS-O group treated by rescue therapy and Non ICAS-O group. RStudio software 1.3.959 was used to perform this meta-analysis.

RESULTS

Ten studies were included with a total of 1639 patients, of which 450 (27.5 %) were in the ICAS-O group treated with intracranial angioplasty and/or stenting, and 1189 (72.5 %) were in the Non ICAS-O group. Overall, intracranial angioplasty and/or stenting did not improve the recanalization rate (OR, 0.67 [0.26-1.76]; p = 0.419) or favorable functional outcome (OR, 1.01 [0.64-1.58]; p = 0.97) in patients with underlying ICAS-O, and the risk of sICH (OR, 0.99 [0.59-1.68]; p = 0.983) and mortality (OR, 1.26 [0.87-1.83]; p = 0.225) did not significantly differ between ICAS-O and Non ICAS-O.

CONCLUSIONS

From these observational study results, rescue intracranial angioplasty and/or stenting seems safe in patients with emergent LAO after attempted thrombectomy, but further rigorous studies are warranted to confirm its efficacy.

Safety and Angiographic Efficacy of Intra-Arterial Fibrinolytics as Adjunct to Mechanical Thrombectomy: Results from the INFINITY Registry

Background and Purpose

Data on safety and efficacy of intra-arterial (IA) fibrinolytics as adjunct to mechanical thrombectomy (MT) are sparse.

Methods

INtra-arterial FIbriNolytics In ThrombectomY (INFINITY) is a retrospective multi-center observational registry of consecutive patients with anterior circulation large-vessel occlusion ischemic stroke treated with MT and adjunctive administration of IA fibrinolytics (alteplase [tissue plasminogen activator, tPA] or urokinase [UK]) at 10 European centers. Primary outcome was the occurrence of symptomatic intracranial hemorrhage (sICH) according to the European Cooperative Acute Stroke Study II definition. Secondary outcomes were mortality and modified Rankin Scale (mRS) scores at 3 months.

Results

Of 5,612 patients screened, 311 (median age, 74 years; 44.1% female) received additional IA after or during MT (194 MT+IA tPA, 117 MT+IA UK). IA fibrinolytics were mostly administered for rescue of thrombolysis in cerebral infarction (TICI) 0-2b after MT (80.4%, 250/311). sICH occurred in 27 of 308 patients (8.8%), with an increased risk in patients with initial TICI0/1 (adjusted odds ratio [aOR], 2.3; 95% confidence interval [CI], 1.1 to 5.0 per TICI grade decrease) or in those with intracranial internal carotid artery occlusions (aOR, 3.7; 95% CI, 1.2 to 12.5). In patients with attempted rescue of TICI0-2b and available angiographic follow-up, 116 of 228 patients (50.9%) showed any angiographic reperfusion improvement after IA fibrinolytics, which was associated with mRS ≤2 (aOR, 3.1; 95% CI, 1.4 to 6.9).

Conclusions

Administration of IA fibrinolytics as adjunct to MT is performed rarely, but can improve reperfusion, which is associated with better outcomes. Despite a selection bias, an increased risk of sICH seems possible, which underlines the importance of careful patient selection.

Feasibility and safety of the strategy of first stenting without retrieval using Solitaire FR as a treatment for emergent large-vessel occlusion due to underlying intracranial atherosclerosis

OBJECTIVE

The optimal treatment for underlying intracranial atherosclerosis (ICAS) in patients with emergent large-vessel occlusion (ELVO) remains unclear. Reocclusion during endovascular treatment (EVT) occurs frequently (57.1%-77.3%) after initial recanalization with stent retriever (SR) thrombectomy in ICAS-related ELVO. This study aimed to compare treatment outcomes of the strategy of first stenting without retrieval (FRESH) using the Solitaire FR versus SR thrombectomy in patients with ICAS-related ELVO.

METHODS

The authors retrospectively reviewed consecutive patients with acute ischemic stroke and intracranial ELVO of the anterior circulation who underwent EVT between January 2017 and December 2019 at Yeungnam University Medical Center. Large-vessel occlusion (LVO) of the anterior circulation was classified by etiology as follows: 1) no significant stenosis after recanalization (embolic group) and 2) remnant stenosis > 70% or lesser degree of stenosis with a tendency toward reocclusion and/or flow impairment during EVT (ICAS group). The ICAS group was divided into the SR thrombectomy group (SR thrombectomy) and the FRESH group.

RESULTS

A total of 105 patients (62 men and 43 women; median age 71 years, IQR 62.5-79 years) were included. The embolic, SR thrombectomy, and FRESH groups comprised 66 (62.9%), 26 (24.7%), and 13 (12.4%) patients, respectively. There were no significant differences between the SR thrombectomy and FRESH groups in symptom onset-to-door time, but puncture-to-recanalization time was significantly shorter in the latter group (39 vs 54 minutes, p = 0.032). There were fewer stent retrieval passes but more first-pass recanalizations in the FRESH group (p < 0.001). Favorable functional outcomes were significantly more frequent in the FRESH group (84.6% vs 42.3%, p = 0.017).

CONCLUSIONS

This study's findings suggest that FRESH, rather than rescue stenting, could be a treatment option for ICAS-related ELVO.

Rescue permanent LVIS stenting with post-stenting angioplasty after failed mechanical thrombectomy for refractory internal carotid artery occlusion at the paraclinoid segment: two-case report

BACKGROUND

Previous studies indicated the effectiveness of permanent stenting when dealing with retriever-failed refractory large vascular occlusion (LVO). Variety types of stents were implanted permanently to achieve recanalization. Low-profile visualized intraluminal support (LVIS) is generally used as a supportive device for embolization of intracranial aneurysm. Its specific structural and functional characteristics contribute to its potential of treating LVO.

CASES PRESENTATION

A 51-year-old male was transferred to our stroke center because of conscious disturbance with the weakness of the left upper limb. The National Institute of Health Stroke Scale (NIHSS) was 24; the Glasgow Coma Scale (GCS) was 10. Digital subtraction angiography (DSA) showed that his paraclinoid segment of R-ICA was occluded due to hard clot embolization. Thrombectomy was performed 6 times, but the occlusion remained. Finally, LVIS was implanted permanently and post-dilation was performed, which successfully recanalized the artery (eTICI 2c). The post-operative NIHSS and GCS were 20 and 11, respectively, which were 10 and 14 when discharged. Another patient was a 71-year-old male who suffered weakness of left limbs. NIHSS was 15; GCS was 11. DSA confirmed that the paraclinoid segment of his R-ICA was occluded due to hard clot embolization. Totally 6 times of mechanical thrombectomy, angioplasty, and tirofiban infusion were performed, which failed to recanalize the artery. In the end, LVIS implantation with post-dilation was performed, and full recanalization was achieved (mTICI 3). The post-operative NIHSS and GCS were 9 and 15, respectively, which were 3 and 15 when discharged.

CONCLUSIONS

These 2 cases invited LVIS into the treatment of refractory occlusion due to hard clot embolization at the paraclinoid segment, and the outcomes were preferable because of the higher visibility, higher flexibility, and lower cell size of LVIS.

Recanalization Therapy for Acute Ischemic Stroke with Large Vessel Occlusion: Where We Are and What Comes Next?

In the past 5 years, the success of multiple randomized controlled trials of recanalization therapy with endovascular thrombectomy has transformed the treatment of acute ischemic stroke with large vessel occlusion. The evidence from these trials has now established endovascular thrombectomy as standard of care. This review will discuss the chronological evolution of large vessel occlusion treatment from early medical therapy with tissue plasminogen activator to the latest mechanical thrombectomy. Additionally, it will highlight the potential areas in endovascular thrombectomy for acute ischemic stroke open to exploration and further progress in the next decade.

Acute ischemic stroke endovascular therapy

Endovascular therapy (EVT) has become the standard treatment for large-vessel occlusion (LVO) acute ischemic stroke (AIS). EVT is now indicated in patients up to 24h from their last known well, provided that the patient meets specific clinical and imaging criteria. Improvements in thrombectomy devices, techniques, and operator experience have allowed successful EVT of ICA terminus, M1-MCA occlusions as well as proximal M2-MCA, basilar artery occlusions, and revascularization of tandem lesions. Mechanical thrombectomy failures still occur due to several factors, however, highlighting the need for further device and technical improvements. An ongoing debate exists regarding the need for pre-EVT thrombolytic agents, thrombectomy techniques, distal occlusions, anesthesia methods, the role of advanced neuroimaging, the treatment of patients with larger infarct core, and those presenting with milder stroke symptoms. Many of these questions are the subject of current or upcoming clinical trials. This review aims to provide an outline and discussion about the established recommendations and emerging topics regarding EVT for LVO AIS.

The use of cangrelor in neurovascular interventions: a multicenter experience

PURPOSE

Thromboembolic events represent the most common procedure-related complication associated with neurointerventions. Cangrelor is a potent, intravenous (IV), P2Y12-receptor antagonist with a rapid onset and offset presented as an alternative antiplatelet agent. We aim to evaluate the safety and effectiveness of IV cangrelor in neurovascular intervention.

METHODS

This is a retrospective analysis of data from four cerebrovascular interventional centers. We identified patients who underwent acute neurovascular intervention and received cangrelor as part of their optimum care. Patients were divided into 2 groups: ischemic and aneurysm. Periprocedural thromboembolic events, hemorrhagic complications, and outcomes were analyzed.

RESULTS

Sixty-six patients were included, 42 allocated into the ischemic group (IG), and 24 into aneurysm group (AG). The IG periprocedural symptomatic complication rate was 9.5%, represented by 3 postoperative intracranial hemorrhages and 1 retroperitoneal hematoma. At discharge, 47.6% had a favorable outcome and the mortality rate was 2.4%, related to clinical deterioration of a large infarct. In the AG, 4.2% had a periprocedural complication during or after cangrelor infusion, represented by an intracranial hemorrhage in an initially ruptured aneurysm. Favorable clinical outcome was seen in 56.2% and 87.7% of ruptured and unruptured aneurysms, respectively, upon discharge.

CONCLUSIONS

Cangrelor may be a feasible alternative for patients requiring immediate intervention with the use of endoluminal devices. It allows the possibility for a secure transition to long-term ticagrelor and progression to surgery in the setting of unexpected complications.

Current knowledge of large vascular occlusion due to intracranial atherosclerosis: focusing on early diagnosis

Intracranial atherosclerosis (ICAS)-related large vascular occlusion (LVO) was an intractable subtype of acute ischemic stroke (AIS), which always needed rescue angioplasty and stenting and complicated the procedure of endovascular recanalization. Diagnosing ICAS-LVO accurately and early was helpful for both clinical treatment and trials. Digital subtraction angiography (DSA) was unable to provide an early and rapid diagnosis of ICAS-LVO based on current studies. A variety of pre-DSA methods had been used to distinguish ICAS-LVO with other subtypes of ischemic stroke, such as medical histories, clinical presentations, computed tomography or angiography (CT/CTA), and magnetic resonance imaging (MRI/MRA). This article briefly reviewed the status quo of the diagnosis and treatment of ICAS-LVO and summarized early diagnostic methods of ICAS-LVO from different aspects.

Y-Stent Rescue Technique for Failed Thrombectomy in Patients With Large Vessel Occlusion: A Case Series and Pooled Analysis

Objective: Y-stent thrombectomy is a recent rescue technique for failed thrombectomy in patients with emergent large vessel occlusion. We presented case series of using Y-stent rescue technique at different sites and investigate its feasibility and safety through pooled analysis of collected case report or series. Methods: Twenty-eight cases were screened from stroke databank who underwent thrombectomy between January 2015 and June 2019. Clinical, procedural, and follow-up data were investigated and pooled analysis of published literature was analyzed. Results: The occlusion sites include carotid terminus in 14 patients; siphon segment in 3; middle cerebral artery (MCA) in 4; basilar terminus in 7. The overall recanalization rate reached 85.7% (arterial occlusive lesion score 2-3); and final reperfusion rate 85.7% (modified Thrombolysis in Cerebral Infarction 2b-3). After literature review, totally, 52 cases were included. Good clinical outcome was achieved in 26 (50%) and mortality in 7 (17.3%). There is no significant difference on the SAH complication at different sites. Literature review shows no difference between each site in the reperfusion and complication rate. Conclusion: Our case series results suggest that high recanalization rate can be effectively achieved with Y-stent rescue technique for patients with refractory emergent large vessel occlusion. The safety of using this technique at different sites needs further investigation for patients.

A DELPHI consensus statement on antiplatelet management for intracranial stenting due to underlying atherosclerosis in the setting of mechanical thrombectomy

PURPOSE

There is little data and lack of consensus regarding antiplatelet management for intracranial stenting due to underlying intracranial atherosclerosis in the setting of endovascular treatment (EVT). In this DELPHI study, we aimed to assess whether consensus on antiplatelet management in this situation among experienced experts can be achieved, and what this consensus would be.

METHODS

We used a modified DELPHI approach to address unanswered questions in antiplatelet management for intracranial stenting due to underlying atherosclerosis in the setting of EVT. An expert-panel (19 neurointerventionalists from 8 countries) answered structured, anonymized on-line questionnaires with iterative feedback-loops. Panel-consensus was defined as agreement ≥ 70% for binary closed-ended questions/≥ 50% for closed-ended questions with > 2 response options.

RESULTS

Panel members answered a total of 5 survey rounds. They acknowledged that there is insufficient data for evidence-based recommendations in many aspects of antiplatelet management for intracranial stenting due to underlying atherosclerosis in the setting of EVT. They believed that antiplatelet management should follow a standardized regimen, irrespective of imaging findings and reperfusion quality. There was no consensus on the timing of antiplatelet-therapy initiation. Aspirin was the preferred antiplatelet agent for the peri-procedural period, and oral Aspirin in combination with a P2Y12 inhibitor was the favored postprocedural regimen.

CONCLUSION

Data on antiplatelet management for intracranial stenting due to underlying atherosclerosis in the setting of EVT are limited. Panel-members in this study achieved consensus on postprocedural antiplatelet management but did not agree upon a preprocedural and intraprocedural antiplatelet regimen. Further prospective studies to optimize antiplatelet regimens are needed.

Direct Stenting of Intracranial Atherosclerosis-related Acute Large Vessel Occlusion

PURPOSE

Endovascular reperfusion therapy (ERT) in patients with intracranial atherosclerosis (ICAS)-related acute large vessel occlusion (ALVO) may require different strategies based on the underlying culprit plaque lesion. This study investigated the effectiveness and safety of direct stent placement in ICAS-related ALVO compared with initially attempted mechanical thrombectomy (MT) with or without rescue treatment.

METHODS

Direct stenting for ICAS-related ALVO was performed in 30 consecutive patients between January 1, 2012, and December 31, 2018. As a control for comparison, MT with or without rescue stenting for patients with ICAS-related ALVO was performed in 73 consecutive patients during the same period. Clinical outcomes were assessed by measuring modified Rankin Scale (mRS) at 90 days.

RESULTS

Patients who underwent direct stenting and those who underwent MT with or without rescue stenting showed no significant differences in baseline characteristics. There was a higher proportion of patients with mRS 0-2 at 90 days in the direct stenting group than in the MT with or without rescue stenting group [24 (80.0%) vs. 34 (46.6%); p = 0.004]. Successful recanalization to modified thrombolysis in cerebral infarction category 2b or 3 was achieved in 93.3% of patients who underwent direct stenting, and in 90.4% of patients who underwent MT with or without rescue stenting.

CONCLUSION

Direct stenting is an effective and safe option for ICAS-related ALVO. Further studies are needed to confirm that endovascular treatments are effective and safe in patients with ALVO and underlying ICAS.

Immediate effects of first-line thrombectomy devices for intracranial atherosclerosis-related occlusion: stent retriever versus contact aspiration

BACKGROUND

Although stent retriever (SR) is recommended as a frontline device of endovascular treatment (EVT) for embolic large artery occlusion causing acute ischemic stroke, contact aspiration (CA) device showed similar efficacy in the recent trials. However, the efficacy of the both devices as first-line therapy for intracranial atherosclerotic stenosis (ICAS)-related large vessel occlusion has not yet been established. Therefore, we compared the immediate effects and final outcomes of SR and CA as first-line devices for treating ICAS-related occlusions.

METHODS

We retrospectively analyzed the data of patients who underwent EVT for acute ischemic stroke from the registry of three Korean hospitals. Patients with ICAS-related occlusion who were treated within 24 h of onset of the symptoms were included. We investigated immediate reperfusion performance, immediate safety outcomes, and 3-month clinical outcomes for the two first-line devices.

RESULTS

Of the 720 registered patients, 111 were eligible for this study. Forty-nine patients (44.1%) used SR and 62 (55.9%) used CA as the first-line device. Achieving successful reperfusion immediately after first-line thrombectomy was more frequent in the SR group than that in the CA group (77.6% vs. 43.5%, p = 0.001), with fewer additional rescue treatments (12.2% vs. 59.7%, p < 0.001). The incidence of iatrogenic dissection or rupture was lower in the SR group than that in the CA group (8.2% vs. 29.0%, p = 0.012). After additional rescue treatments, however, the final successful reperfusion rate did not differ between the two groups (SR 87.8% vs. CA 77.4%, p = 0.247), and there was no significant difference in the 3-month good outcomes (modified Rankin Scale, p = 0.524).

CONCLUSIONS

First-line SR thrombectomy showed higher immediate reperfusion and less vessel injury for ICAS-related occlusions than CA. However, there was no significant difference in the final reperfusion status or 3-month outcomes from additional rescue treatments.

Intra-Arterial Glycoprotein IIb/IIIa Inhibitor Treatment for Symptomatic Intracranial Atherosclerotic Stenosis Presenting as Large Vessel Occlusions

Introduction

There is no consensus on the optimal treatment for acute ischemic stroke (AIS) large vessel occlusions (LVOs) or near-occlusions with underlying intracranial atherosclerotic stenosis (ICAS). We report the first American series using intra-arterial (IA) glycoprotein IIb/IIIa inhibitors (GPIs) as a stand-alone revascularization technique for ICAS presenting with large vessel ischemic syndromes.

Methods

Records at two centers of 140 patients presenting with AIS undergoing stroke intervention from January 2017 to June 2019 were retrospectively reviewed. Patients treated with IA GPIs were identified, and baseline factors, imaging, procedural characteristics, hospital course, and outcomes were collected. Six patients with ICAS underlying their acute symptomatic near occlusion or LVO were treated with IA GPI. Four near-occlusions were treated with IA GPI as the first-line therapy, while two LVOs were treated with IA GPI as an adjunct therapy to thrombectomy.

Results

The mean age was 61.3 years (range 36-79), presentation National Institute of Health Stroke Scale (NIHSS) was 10 (4-18), time from last seen well to treatment was 434.5 minutes (164-1290), and time from groin puncture to revascularization was 67.3 minutes (26-94). Three patients received intravenous (IV) tissue plasminogen activator (tPA), and all patients received an IA weight-based GPI infusion. Five patients had thrombolysis in cerebral ischemia (TICI) 3, and one patient had TICI 2b. The mean discharge NIHSS was 2.5 (0-8). The mean modified Rankin scale was 1.3 (range 0-4) at discharge and .8 at three months. No patients had a postprocedural symptomatic hemorrhage.

Conclusion

Our results highlight the utility of IA GPI administration as the first-line therapy for symptomatic ICAS near occlusions or as a rescue technique after failed thrombectomy for LVO patients suspected of underlying ICAS.

Use of intracranial stent as rescue therapy after mechanical thrombectomy failure-9-year experience in a comprehensive stroke centre

PURPOSE

There is no established rescue treatment in patients with mechanical thrombectomy (MT) failure. Our aim is to analyse whether the use of an intracranial stent improves prognosis in these patients.

METHODS

Retrospective analysis of a prospective cohort of patients with ischemic stroke due to middle cerebral artery occlusion (MCA) or distal intracranial carotid artery (ICA) occlusion, from September 2009 to April 2019 in our comprehensive stroke care centre. Patients with MT failure were identified and dichotomized into two groups according to whether or not an intracranial stent was implanted. We analysed clinical outcomes in both groups.

RESULTS

There was MT failure in 60 patients (14%) of the 433 with large vessel occlusion in distal ICA and proximal MCA. A stent was placed in 20 of them (33.3%). Compared to patients without rescue stenting, they showed better rates of independence at 3 months (mRS ≤ 2) 45% vs 2.5% (p < 0.001) and lower mortality 15% vs 50% (p = 0.009), maintaining statistical significance after multivariate analysis, without a significant increase of the rate of symptomatic intracranial haemorrhage (p = 0.209).

CONCLUSION

Placement of an intracranial stent as rescue therapy after MT failure was associated with better clinical outcome without significant increase in haemorrhagic complications. We believe that this procedure should be appraised in these patients.

Motor evoked potentials during revascularization in ischemic stroke predict motor pathway ischemia and clinical outcome

OBJECTIVE

The relevance of motor evoked potential (MEP) recovery during mechanical endovascular thrombectomy (MT) in patients with ischemic stroke is unclear. We correlated MEP recovery during MT to symptom improvement and to ischemia in eloquent motor areas on magnetic resonance imaging (MRI) and compared the predictive value of MEPs to visual angiographic reperfusion status, classified by modified Thrombolysis in Cerebral Infarction grading (mTICI).

METHODS

Patients with hemisyndrome and large-vessel occlusion undergoing MT were included (n35, 49% females; 73.9 ± 14.5 years; n31 anterior circulation). MEPs were elicited transcranially and recorded at the abductor pollicis brevis muscle bilaterally throughout the procedure. An MRI was acquired within 7 days after MT.

RESULTS

The median door-to-needle time was 3.5 hours. Median National Institutes of Health Stroke Scale at presentation was 16 (7 - 37). Median Modified Rankin Scale score was 4 at day 7 and 3 months. After MT, MEP-recovery occurred in 21 cases after a median time span of 4.5 min [range 2 - 11 min]. Symptom improvement at day 7 (3 months) was noted in 22 (21) cases. Absence of ischemia on postinterventional MRI was noted in 21 cases, 19 of whom showed MEP-recovery. Stratified for symptom improvement at day 7, sensitivity (specificity) of MEP-recovery was 86% (85%) and of mTICI ≥ 2b was 95% (23%). Stratified for absence of ischemia on postinterventional MRI, sensitivity (specificity) of MEP-recovery was 90% (86%) and of mTICI ≥ 2b was of 95% (21%).

CONCLUSIONS

MEP recovery occurs early after successful endovascular mechanical revascularization and is superior to mTICI grading in predicting postoperative neurological outcome and postoperative motor-pathway ischemia.

SIGNIFICANCE

This is a new, significant and clinically important study since it emphasizes the additional value of MEP monitoring in a field, which has been traditionally unaffiliated with neurophysiological monitoring.

Treatment Strategies for Tandem Occlusions in Acute Ischemic Stroke

There is no consensus for the treatment of a tandem occlusion (TO) in a patient presenting with an acute ischemic stroke. In this review article, we will focus on the controversial treatment strategies for TOs. First, we will discuss treatment options including retrograde, antegrade, and delayed approaches. Second, the role of carotid stent placement versus balloon angioplasty for the extracranial occlusion will be presented. Third, anticoagulation and antiplatelet regimens for the treatment TOs published in the literature will be reviewed. Finally, we will discuss whether there is a role for coil occlusion of the cervical carotid artery or whether staged carotid revascularization days after mechanical thrombectomy of the intracranial occlusion maybe appropriate. The optimal treatment strategy of TO has not been established and further larger trials need to be performed to answer the question.

Emergency Intracranial Stenting in Acute Stroke: Predictors for Poor Outcome and for Complications

Background

Stent‐retriever thrombectomy is the first‐line therapy in acute stroke with intracranial large vessel occlusion. In case of failure of stent‐retriever thrombectomy, rescue stent angioplasty might be the only treatment option to achieve permanent recanalization. This study aims at identifying predictors for poor outcome and complications in a large, multicenter cohort receiving rescue stent angioplasty.

Methods and Results

We performed a retrospective analysis of patients with large vessel occlusion who were treated with rescue stent angioplasty after stent‐retriever thrombectomy between 2012 and 2018 in 7 neurovascular centers. We defined 2 binary outcomes: (1) functional clinical outcome (good modified Rankin Scale, 0–2; and poor modified Rankin Scale, 4–6) and (2) early symptomatic intracerebral hemorrhage. Impacts of clinical, radiological, and interventional parameters on outcomewere assessed in uni‐ and multivariable logistic regression models. Two hundred ten patients were included with target vessels located within the anterior circulation (136 of 210; 64.8%) and posterior circulation (74 of 210; 35.2%). Symptomatic intracerebral hemorrhage occured in 22 patients, 86.4% (19 of 22) after anterior and 13.6% (3 of 22) after posterior circulation large vessel occlusion. Good functional outcome was observed in 44.8% (73 of 163). A higher National Institutes of Health Stroke Scale on admission (adjusted odds ratio, 1.10; P=0.002), a higher premorbid modified Rankin Scale (adjusted odds ratio, 2.02; P=0.049), and a modified Thrombolysis in Cerebral Infarction score of 0 to 2a after stenting (adjusted odds ratio, 23.24; P<0.001) were independent predictors of poor functional outcome.

Conclusions

Use of rescue stent angioplasty can be considered for acute intracranial large vessel occlusion in cases after unsuccessful stent‐retriever thrombectomy. Likelihood of symptomatic intracerebral hemorrhage is higher in anterior circulation stroke.

Neuroanatomy of the middle cerebral artery: implications for thrombectomy

Our perspective on anatomy frequently depends on how this anatomy is utilized in clinical practice, and by which methods knowledge is acquired. The thrombectomy revolution, of which the middle cerebral artery (MCA) is the most common target, is an example of a clinical paradigm shift with a unique perspective on cerebrovascular anatomy. This article reviews important features of MCA anatomy in the context of thrombectomy. Recognizing that variation, frequently explained by evolutionary concepts, is the rule when it comes to branching pattern, vessel morphology, territory, or collateral potential is key to successful thrombectomy strategy.

Intracranial Stenting After Failed Thrombectomy in Patients With Moderately Severe Stroke: A Multicenter Cohort Study

Background and Purpose: Recently, acute intracranial stenting (ICS) has gained more interest as a potential bailout strategy for large vessel occlusions (LVO) that are refractory to thrombectomy. However, there are currently no reports on ICS in patients with moderately severe stroke discussing the question if implementing a permanent stent is feasible and leads to improved recanalization after failed thrombectomy. Methods: We analyzed a large multicenter database of patients receiving ICS for anterior circulation LVO after failed thrombectomy. Inclusion criteria were defined as: Moderately severe stroke (National Institute Health Stroke Scale (NIHSS) ≤9 on admission), anterior circulation LVO, acute ICS after failed stent retriever MT. Primary endpoint was the rate of improved successful recanalization after ICS defined as a modified Thrombolysis In cerebral Infarction (mTICI) score≥2b. Favorable neurological outcome was defined as an early neurological improvement (ENI) of 4 points or reaching 0 with respect to baseline NIHSS. Results: Forty-one patients met the inclusion criteria. A median of 2 retrievals were performed (IQR 1-4) prior decision-making for ICS. ICS led in 90.2% (37/41) of cases to a final mTICI≥2b with significant improvement (p < 0.001) after the last retrieval attempt. The median NIHSS decreased (p = 0.178) from 7 (IQR 3.5-8) on admission to 2.5 (IQR 0-8.25) at discharge. ENI was observed in 47.4% (18/38). sICH occurred in 4.8% (2/41). Conclusion: ICS after failed thrombectomy appears to effectively improve recanalization rates in patients with moderately severe strokes. Thus, ICS should be considered also for patients with baseline NIHSS ≤9 if thrombectomy fails.

Endovascular Thrombectomy of Calcified Emboli in Acute Ischemic Stroke: A Multicenter Study

BACKGROUND AND PURPOSE

Large intracranial vessel occlusion due to calcified emboli is a rare cause of major stroke. We assessed the prevalence, imaging appearance, the effectiveness of mechanical thrombectomy, and clinical outcome of patients with large-vessel occlusion due to calcified emboli.

MATERIALS AND METHODS

We performed a retrospective analysis of clinical and procedural data of consecutive patients who underwent mechanical thrombectomy due to calcified emboli in 7 European stroke centers.

RESULTS

We screened 2969 patients, and 40 patients matched the inclusion criteria, accounting for a prevalence of 1.3%. The mean maximal density of the thrombus was 327 HU (range, 150-1200 HU), and the mean thrombus length was 9.2 mm (range, 4-20 mm). Four patients had multiple calcified emboli, and 2 patients had an embolic event during an endovascular intervention. A modified TICI score of ≥2b was achieved in 57.5% (23/40), with minimal-to-no reperfusion (modified TICI 0-1) in 32.5% (13/40) and incomplete reperfusion (modified TICI 2a) in 10% (4/40). Excellent outcome (mRS 0-1) was achieved in only 20.6%, functional independence (mRS 0-2) in 26.5% and 90-day mortality was 55.9%.

CONCLUSIONS

Acute ischemic stroke with large-vessel occlusion due to calcified emboli is a rare entity in patients undergoing thrombectomy, with considerably worse angiographic outcome and a higher mortality compared with patients with noncalcified thrombi. Good functional recovery at 3 months can still be achieved in about a quarter of patients.

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

Purpose

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

Methods

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

Results

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

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

Conclusion

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

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

Current Opinion on Endovascular Therapy for Emergent Large Vessel Occlusion Due to Underlying Intracranial Atherosclerotic Stenosis

For recanalization of emergent large vessel occlusions (ELVOs), endovascular therapy (EVT) using newer devices, such as a stent retriever and large-bore catheter, has shown better patient outcomes compared with intravenous recombinant tissue plasminogen activator only. Intracranial atherosclerotic stenosis (ICAS) is a major cause of acute ischemic stroke, the incidence of which is rising worldwide. Thus, it is not rare to encounter underlying ICAS during EVT procedures, particularly in Asian countries. ELVO due to underlying ICAS is often related to EVT procedure failure or complications, which can lead to poor functional recovery. However, information regarding EVT for this type of stroke is lacking because large clinical trials have been largely based on Western populations. In this review, we discuss the unique pathologic basis of ELVO with underlying ICAS, which may complicate EVT procedures. Moreover, we review EVT data for patients with ELVO due to underlying ICAS and suggest an optimal endovascular recanalization strategy based on the existing literature. Finally, we present future perspectives on this subject.

Rescue stenting versus medical care alone in refractory large vessel occlusions: a systematic review and meta-analysis

PURPOSE

Mechanical thrombectomy (MT) failure is associated with very poor prognosis. Permanent intracranial stenting (PIS) may be useful in such refractory occlusions. However, this strategy requires an aggressive antithrombotic regimen that may be harmful in extended strokes. The aim of this study was to compare clinical outcomes between patients with refractory acute large vessel occlusions (LVOs) treated by PIS versus patients for whom the procedure was stopped without recanalization.

METHODS

We conducted a systematic review by searching for articles in PubMed, the Cochrane Library, and ClinicalTrials.gov from January 2015 to September 2019. Two reviewers independently selected studies comparing PIS after failed MT in addition to usual care versus usual care only. A comparative meta-analysis was performed using random-effects models to estimate odds ratios of favorable clinical outcome at 90 days, defined as a modified Rankin scale 0-2, mortality and symptomatic intracranial hemorrhage (SICH).

RESULTS

Four comparative studies were included for a total of 352 patients: 149 in the PIS group versus 203 in the control group. PIS was associated with significantly higher rates of 90-day favorable clinical outcome (odds ratio [OR], 2.87 [95% confidence interval (95% CI), 1.77-4.66]; p < 0.001; I², 0%) and lower mortality (OR, 0.39 [0.16-0.93]; p = 0.03; I², 43%), whereas SICH rates did not significantly differ (OR, 0.68 [0.37-1.27]; p = 0.23; I², 0%).

CONCLUSION

From observational study results, attempting PIS after failed MT seems to improve clinical outcomes without increasing the risk of intracranial bleeding. Randomized trials are needed to confirm these results.

Stenting of Mobile Calcified Emboli After Failed Thrombectomy in Acute Ischemic Stroke: Case Report and Literature Review

BACKGROUND

Mobile calcified emboli are a rare cause of large vessel occlusion and acute ischemic stroke and pose unique challenges to standard mechanical thrombectomy techniques. Intracranial stenting has been reported as a rescue maneuver in cases of failed mechanical thrombectomy owing to dissection or calcified atherosclerotic plaques, but its use for calcified emboli is not well described.

CASE DESCRIPTION

We present 2 cases of acute ischemic stroke caused by mobile calcified emboli. Standard mechanical thrombectomy techniques using aspiration catheters and stent-retrievers failed to remove these emboli, so intracranial stenting was successfully performed in each case, albeit after overcoming unique challenges associated with the stenting of calcified emboli. We also review the literature on intracranial stenting as a salvage therapy for failed mechanical thrombectomy.

CONCLUSIONS

Mobile calcified emboli are rare causes of acute ischemic stroke. Intracranial stenting can be used to successfully treat calcified emboli when mechanical thrombectomy has failed.

Platelet Glycoprotein IIb/IIIa Receptor Inhibitor Tirofiban in Acute Ischemic Stroke

Tirofiban is a non-peptide selective glycoprotein (GP) IIb/IIIa receptor inhibitor that reversibly inhibits fibrinogen-dependent platelet aggregation and subsequent formation of thrombi, which contribute to the major atherosclerotic complications in the development, progression, and resolution of ischemic stroke. The adjunctive use of tirofiban has been extensively evaluated in progressive stroke, combined intravenous thrombolysis (IVT), and endovascular treatment (EVT) in both preclinical and clinical studies. A body of evidence has been accumulated on the risks and benefits associated with tirofiban in terms of prevention of stroke progression, stent thrombosis, improvement in functional independence, and mortality, especially among high-risk ischemic stroke patients as a further strategy alongside conventional treatment. In general, tirofiban has a favorable tolerability and efficacy profile in the improvement of vascular recanalization and long-term functional outcome, although the optimum dosage, application setting, and precise target patients are not yet well-established. However, its specific inhibition of ongoing platelet aggregation and thrombus formation rather than absolute thrombolysis suggests that tirofiban, one of the most widely used GP IIb/IIIa inhibitors, with high affinity and a short plasma/biologic half-life, may have great potential in the acute treatment of ischemic stroke. Substantial practical progress is likely as our understanding of the mechanism of action and pharmacological actions of tirofiban in atherosclerotic ischemic disease improves. Therefore, we classify and summarize the available findings regarding tirofiban in acute ischemic stroke to stimulate and guide further research and clinical practice.

Platelets as Modulators of Cerebral Ischemia/Reperfusion Injury

Ischemic stroke is among the leading causes of disability and death worldwide. In acute ischemic stroke, the rapid recanalization of occluded cranial vessels is the primary therapeutic aim. However, experimental data (obtained using mostly the transient middle cerebral artery occlusion model) indicates that progressive stroke can still develop despite successful recanalization, a process termed “reperfusion injury.” Mounting experimental evidence suggests that platelets and T cells contribute to cerebral ischemia/reperfusion injury, and ischemic stroke is increasingly considered a thrombo-inflammatory disease. The interaction of von Willebrand factor and its receptor on the platelet surface, glycoprotein Ib, as well as many activatory platelet receptors and platelet degranulation contribute to secondary infarct growth in this setting. In contrast, interference with GPIIb/IIIa-dependent platelet aggregation and thrombus formation does not improve the outcome of acute brain ischemia but dramatically increases the susceptibility to intracranial hemorrhage. Here, we summarize the current understanding of the mechanisms and the potential translational impact of platelet contributions to cerebral ischemia/reperfusion injury.

Effects of first pass recanalization on outcomes of contact aspiration thrombectomy

BACKGROUND

First pass recanalization (FPR, defined as achieving a modified Thrombolysis in Cerebral Ischemia (mTICI) grade 2c/3 with a single pass of a thrombectomy device) effect has not yet been evaluated in contact aspiration thrombectomy (CAT). We evaluated FPR effect on clinical outcomes and FPR predictors in CAT.

METHODS

All consecutive patients who underwent frontline CAT for anterior circulation large vessel occlusion with recanalization (mTICI 2b-3) were identified from registries at six stroke centers. The patients were dichotomized into FPR and non-FPR groups. Clinical features and outcomes were compared between the groups. Multivariate analyses were performed to determine whether FPR was independently associated with clinical outcomes and to identify predictors of FPR.

RESULTS

Of the 429 patients who underwent frontline CAT, recanalization was successful in 344 patients (80.2%; mean age 68.7±11.0 years; M:F ratio 179:165). The FPR group had a higher rate of good outcome (modified Rankin Scale score 0-2) than the non-FPR group. Furthermore, the good outcome rate was higher in the FPR group than in patients who achieved mTICI 2c/3 with multiple passes or rescue treatment. FPR (OR 2.587; 95% CI 1.237 to 5.413) remained independently associated with good outcomes, in addition to age, baseline National Institute Health Stroke Scale, and coronary artery disease. The use of a balloon guide catheter (OR 3.071; 95% CI 1.699 to 5.550) was the only predictor of FPR.

CONCLUSIONS

Patients in the FPR group had better clinical outcomes than the non-FPR group in CAT. FPR was independently associated with a good outcome. The use of a balloon guide catheter was the only predictor of FPR.

Efficacy and safety of rescue stenting following failed mechanical thrombectomy for anterior circulation large vessel occlusion: propensity score analysis

PURPOSE

To evaluate the effectiveness and safety of rescue stenting (RS) after failed mechanical thrombectomy (MT) for patients with large artery occlusion in the anterior circulation.

METHODS

Consecutive patients who experienced failed reperfusion and subsequently did or did not undergo RS at 16 comprehensive stroke centers were enrolled from January 2015 to June 2018. Propensity score matching was used to achieve baseline balance between the patient groups. Symptomatic intracranial hemorrhage (sICH) at 48 hours and the modified Rankin Scale scores and mortality at 3 months in the two groups were compared.

RESULTS

A total of 90 patients with RS and 117 patients without RS after failed MT were enrolled. Propensity score matching analysis selected 132 matched patients. The good outcome rate was significantly higher in matched patients with RS than in those without RS (36.4% vs 19.7%, p=0.033), whereas the sICH (13.6% vs 21.2%, p=0.251) and mortality (31.9% vs 43.9%, p=0.151) were not significantly different between the groups.

CONCLUSIONS

RS seems to be an effective safe choice for patients with large vessel occlusion of the anterior circulation who underwent failed MT.

The Safety and Feasibility of Mechanical Thrombectomy for Mild Acute Ischemic Stroke With Large Vessel Occlusion

BACKGROUND

Prospective evidence to support mechanical thrombectomy (MT) for mild ischemic stroke with large vessel occlusion (LVO) is lacking. There is uncertainty about using an invasive procedure in patients with mild symptoms.

OBJECTIVE

To evaluate the safety and feasibility of MT in patients with mild symptoms and LVO.

METHODS

Our single-arm prospective pilot study recruited patients with LVO and initial National Institute of Health Stroke Scale (NIHSS) &lt;6, who underwent standard MT. Primary safety endpoints were symptomatic intracerebral hemorrhage (sICH), and/or worsening NIHSS by ≥4 points. Secondary endpoints included angiographic recanalization, NIHSS change, final infarct volume, and modified Rankin score (mRS).

RESULTS

We enrolled 20 patients (mean age 65.6 ± 12.3 yr; 45% females). Thrombolysis in Cerebral Ischemia 2B/3 thrombectomy was achieved in 95%. No patients suffered sICH. One patient (5%) had neurologic worsening within 24 h because of underlying intracranial stenosis. No other complications or safety concerns were identified. Median NIHSS was significantly better at discharge (0.5, P = .007) and at last follow-up (0, P &lt; .001) than before treatment (3). Mean post vs preintervention infarct volumes were small without significant difference (1.2 ml, P = .434). Most patients (85%) were discharged directly home. Excellent clinical outcome (mRS 0-1) at last follow-up was seen in 95% of patients.

CONCLUSION

This is one of the first specifically designed prospective studies showing that MT is safe and feasible in patients with low NIHSS and LVO. Chronic underlying vasculopathy may be a challenging dilemma. We observed excellent clinical and radiographic outcomes, but randomized controlled trials are needed to demonstrate the efficacy of MT in this unique cohort.

Rescue Intracranial Stenting After Failed Mechanical Thrombectomy for Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

BACKGROUND

Up to 20% of patients fail to achieve reperfusion with modified Thrombolysis in Cerebral Infarction (mTICI) scores of 0-1 after mechanical thrombectomy (MT). Furthermore, underlying intracranial atherosclerotic disease, particularly when associated with >70% residual or flow limiting stenosis, is associated with higher rates of failed MT and high failure risk MT. The aim of this study was to systematically review the procedural and clinical outcomes in patients with failed MT and high failure risk MT. We also explored differences between patients receiving acute rescue stenting compared with medical management alone.

METHODS

A systematic literature search was conducted in Ovid MEDLINE, PubMed, Embase, and Cochrane online scientific publication databases for English language publications from their date of inception until October 2018. Studies including adult patients with acute ischemic stroke because of emergent large vessel occlusion with failed (mTICI score 0-1) or high failure risk MT within the anterior circulation who underwent rescue stenting were included. A systematic review and meta-analysis of proportions was performed.

RESULTS

Rescue intracranial stenting after failed MT or high failure risk MT results in improved clinical outcomes compared with patients without stenting (48.5% vs. 19.7%, respectively; P < 0.001), without an increase in the rate of symptomatic intracranial hemorrhage, despite additional use of antiplatelet agents (9.7% vs. 14.1%, respectively; P = 0.04).

CONCLUSIONS

In patients who fail initial attempts at MT or are high risk for acute reocclusion, rescue intracranial stenting could be considered with the aim to improve functional outcomes. Antiplatelet agents do not increase the risk of hemorrhage in these patients.

Intracranial bailout stenting with the Acclino (Flex) Stent/NeuroSpeed Balloon Catheter after failed thrombectomy in acute ischemic stroke: a multicenter experience

Background and purpose

To report on the feasibility, safety, and outcome of acute intracranial stenting (ICS) with the Acclino (Flex) Stent and NeuroSpeed Balloon Catheter in cases of failed mechanical thrombectomy (MT) for acute ischemic stroke (AIS).

Methods

We retrospectively reviewed the data of patients treated with acute bailout stenting after failed MT in three large neurointerventional centers using exclusively the Acclino (Flex) Stent and the NeuroSpeed Balloon Catheter. Functional outcome was assessed by the rate of major early neurological recovery (mENR) at 24 hours and at 90 days with the modified Rankin Scale (mRS). Safety evaluation included symptomatic intracranial hemorrhage (sICH), mortality, and intervention-related serious adverse events (SAEs).

Results

50 patients with a median age of 71 years met the inclusion criteria and 52% (26/50) of the occluded vessels were located within the anterior circulation. mENR was observed in 38.8% and 90-day favorable outcome (mRS ≤2) was 40.6% (13/32). Higher NIH Stroke Scale scores on admission were significantly associated with poor functional outcome (mRS ≥3) at 90 days (adjusted OR 1.28; 95% CI 1.07 to 1.53; p=0.007). sICH occurred in two cases of the study population. There were no intervention-related SAEs.

Conclusion

Intracranial bailout stenting with the Acclino (Flex) Stent and the NeuroSpeed Balloon Catheter after failed MT is a feasible and effective recanalization method for atherosclerotic stenosis-based stroke that is associated especially with low rates of sICH.

Baseline Occlusion Angiographic Appearance on Mechanical Thrombectomy Suggests Underlying Etiology and Outcome

Background: Etiology of a large vessel occlusion is relevant in the management of acute ischemic stroke patients and often difficult to determine in the acute phase.

Aims: We aim to investigate whether the angiographic appearance of the occlusion is related to its etiology and outcome.

Materials and Methods: Patients without cervical carotid occlusions who underwent mechanical thrombectomy in our center from April 2015 to September 2018 were studied. Demographics, clinical and radiological variables and outcome measures, including etiological classification of stroke, were collected. Underlying intracranial atherosclerosis was estimated according to the presence of stenosis after recanalization. Patients were assigned to groups based on the appearance of the occlusion observed in the first angiogram as “tapered” or “non-tapered.” Differences were searched amongst them.

Results: 131 patients met inclusion criteria. 31 (23.6%) were “tapered” and 100 (76.3%) non-tapered. Tapered presented lower mean baseline NIHSS (10.3 ± 6.2 vs. 16.1 ± 7.2; p < 0.001), smaller acute infarct cores as CTP CBV ASPECTS (8.6 ± 1.6 vs. 7.2 ± 2.4; p = 0.003), higher proportion of instant re-occlusions (26.7 vs. 8.2%; p = 0.025), fewer complete recanalization (45.2 vs. 71.0%; p = 0.028), and more persistent occlusions (37.5 vs. 10.6%; p = 0.011) on follow up MRA. There were no differences in reperfusion rates (83.9 vs. 84.0%; p = 0.986) nor in good long term functional outcome (50.0 vs. 51.1%; p = 0.921). Intracranial atherosclerosis etiology was more common in tapered than in non-tapered occlusions (54.8 vs. 18.0%; p < 0.001).

Conclusion: The angiographic appearance of an occlusion in mechanical thrombectomy patients may determine its etiology, predict likelihood of successful recanalization, and risk of reocclusion.