Adjuvant intra-arterial rt-PA injection at the initially deployed solitaire stent enhances the efficacy of mechanical thrombectomy in acute ischemic stroke

Ischaemic Stroke, Thromboembolism and Clot Structure

Ischaemic stroke is a major cause of morbidity and mortality worldwide. Blood clotting and thromboembolism play a central role in the pathogenesis of ischaemic stroke. An increasing number of recent studies indicate changes in blood clot structure and composition in patients with ischaemic stroke. In this review, we aim to summarise and discuss clot structure, function and composition in ischaemic stroke, including its relationships with clinical diagnosis and treatment options such as thrombolysis and thrombectomy. Studies are summarised in which clot structure and composition is analysed both in vitro from patients' plasma samples and ex vivo in thrombi obtained through interventional catheter-mediated thrombectomy. Mechanisms that drive clot composition and architecture such as neutrophil extracellular traps and clot contraction are also discussed. We find that, while in vitro clot structure in plasma samples from ischaemic stroke patients are consistently altered, showing denser clots that are more resistant to fibrinolysis, current data on the composition and architecture of ex vivo clots obtained by thrombectomy are more variable. With the potential of advances in technologies underpinning both the imaging and retrieving of clots, we expect that future studies in this area will generate new data that is of interest for the diagnosis, optimal treatment strategies and clinical management of patients with ischaemic stroke.

Thrombectomy Plus Intra-Arterial Thrombolysis Versus Thrombectomy for Acute Large Vessel Occlusions: a Matched-Control Study

AIM

We conducted a matched-control analysis to compare the outcomes of large vessel occlusion (LVO) patients treated with mechanical thrombectomy (MT) plus Intra-arterial thrombolysis (IAT) versus those treated with MT alone.

METHODS

The subjects of this study were chosen from ANGEL-ACT registry. All patients who received MT were identified and categorized into two groups: "MT + IAT" and "MT," based on whether or not they received additional intra-arterial medication IAT during the MT procedure. After being subjected to 1:1 propensity score matching, the outcome measures, including modified Rankin Scale (mRS) score at 90 days, successful recanalization at the final angiogram, symptomatic intracranial hemorrhage (sICH) within 36 h, and death within 90 days, were compared.

RESULTS

The study encompassed a total of 1607 patients, with 641 individuals assigned to the MT + IAT group and 966 to the MT group. After applying propensity score matching, a total of 524 pairs were identified for comparison. The results indicated that there were no significant differences between the two groups with regard to the modified Rankin Scale (mRS) score (median: 3 vs. 3 points; P = 0.83), successful recanalization (89.9 vs. 88.9%; P = 0.62), sICH (8.3 vs. 8.7%; P = 0.79), and death (15.5 vs. 16.4%; P = 0.70).

CONCLUSIONS

IAT during MT does not confer an elevated risk of sICH or mortality. Furthermore, the combination of MT and IAT may produce comparable functional outcomes in comparison to MT alone, when treating acute LVO patients.

Mechanical thrombectomy with intra-arterial thrombolysis versus mechanical thrombectomy alone in patients with acute ischemic stroke: A systematic review and meta-analysis

BACKGROUND

There is conflicting evidence as to whether intra-arterial thrombolysis (IAT) adds benefit in patients with acute stroke who undergo mechanical thrombectomy (MT).

METHODS

We conducted a systematic review to identify studies that evaluate IAT in patients with acute stroke who undergo MT. Data were extracted from relevant studies found through a search of PubMed, Scopus, and Web of Science until February 2023. Statistical pooling with random effects meta-analysis was undertaken to evaluate odds of functional independence, mortality, and near-complete or complete angiographic recanalization with IAT compared to no IAT.

RESULTS

A total of 18 studies were included (3 matched, 14 unmatched, and 1 randomized). The odds ratio (OR) for functional independence (modified Rankin Scale: 0-2) at 90 days was 1.14 (95% confidence interval (CI): 0.95-1.37, p = 0.17, 16 studies involving 7572 patients) with IAT with moderate between-study heterogeneity (I2 = 38.1%). The OR for functional independence with IAT was 1.28 (95% CI: 0.92-1.78, p = 0.15) in studies that were either matched or randomized and 1.24 (95% CI: 0.97-1.58, p = 0.08) in studies with the highest quality score. IAT was associated with higher odds of near-complete or complete angiographic recanalization (OR: 1.65, 95% CI: 1.03-2.65, p = 0.04) in studies that were either matched or of randomized comparisons.

CONCLUSION

Although the odds of functional independence appeared to be higher with IAT and MT compared with MT alone, none of the results were statistically significant. A prominent effect of the design and quality of the studies was observed on the association between IAT and functional independence at 90 days.

Adjuvant intra-arterial thrombolysis during mechanical thrombectomy is an effective means of improving outcomes for patients with large vessel occlusion stroke: A systematic review and meta-analysis

OBJECTIVE

It is unknown whether adjunctive intra-arterial thrombolysis (IAT) during mechanical thrombectomy (MT) improves outcomes in patients with large vessel occlusion (LVO) stroke. This systematic review and meta-analysis aimed to compare the safety and efficacy of MT with and without IAT for the treatment of LVO stroke.

METHODS

A systematic literature search of PubMed, Embase, and the Cochrane Library was conducted to identify studies that compared rates of 3-month functional independence (modified Rankin Scale score 0-2), successful revascularization, symptomatic intracranial hemorrhage, and 3-month mortality for MT+IAT and MT alone. Meta-analyses were performed using random effects models, and effect sizes were expressed as odds ratios (ORs) and 95% confidence intervals (CIs). Heterogeneity was assessed with Cochran's Q test and I2 statistic.

RESULTS

Twelve studies met eligibility criteria, comprising one randomized controlled trial and 11 observational cohort studies involving 2584 patients. Compared to MT alone, MT+IAT had a 43% higher odds of 3-month functional independence (OR 1.43, 95% CI 1.11-1.83; I2 =21%) and a 23% decrease in odds for 3-month mortality (OR 0.77, 95% CI 0.60-0.99; I2 =0%). There were no differences in successful revascularization (OR 1.39, 95% CI 0.89-2.17; I2 =57%) or symptomatic intracranial hemorrhage (OR 0.87, 95% CI 0.56-1.35; I2 =6%) between the two groups.

CONCLUSIONS

The present study has demonstrated that, compared with MT alone, the use of adjunct IAT during MT in patients with LVO stroke resulted in better functional outcomes and lower mortality.

Effect of intra-arterial thrombolysis following successful endovascular thrombectomy on functional outcomes in patients with large vessel occlusion acute ischemic stroke: A post-CHOICE meta-analysis

INTRODUCTION

Endovascular thrombectomy (EVT) is the standard treatment of acute ischemic stroke (AIS) due to large vessel occlusion (LVO). Although > 70% of patients in the trials assessing EVT for AIS-LVO had successful recanalization, only a third ultimately achieved favorable outcomes. A "no-reflow" phenomenon due to distal microcirculation disruption might contribute to such suboptimal outcomes. Combining intra-arterial (IA) tissue plasminogen activator (tPA) and EVT to reduce the distal microthrombi burden was investigated in a few studies. We present a pooled-data meta-analysis of the existing evidence of this combinatorial treatment.

METHODS

We followed the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) recommendations. We aimed to include all original studies investigating EVT plus IA tPA in AIS-LVO patients. Using R software, we calculated pooled odds ratios (ORs) with corresponding 95% confidence intervals (CI). A fixed-effects model was adopted to evaluate pooled data.

RESULTS

Five studies satisfied the inclusion criteria. Successful recanalization was comparable between the IA tPA and control groups at 82.9% and 82.32% respectively. The 90-day functional independence was similar between both groups (OR= 1.25; 95% CI= 0.92-1.70; P= 0.154). Symptomatic intracranial hemorrhage (sICH) was also comparable between both groups (OR= 0.66; 95% CI= 0.34-1.26; P= 0.304).

CONCLUSION

Our current meta-analysis does not show significant differences between EVT alone and EVT plus IA tPA in terms of functional independence or sICH. However, with the limited number of studies and included patients, more randomized controlled trials (RCTs) are needed to further investigate the benefits and safety of combined EVT and IA tPA.

Mechanical thrombectomy with intra-arterial alteplase provided better functional outcomes for AIS-LVO: a meta-analysis

Background

Several clinical trials have shown that intra-arterial thrombolysis using alteplase during mechanical thrombectomy (MT) has a better outcome than MT alone in ischemic stroke management. We performed the current meta-analysis to estimate the efficacy and safety of MT with intra-arterial alteplase therapy.

Methods

The MEDLINE, Embase, Cochrane Library, and ClinicalTrials.gov databases were searched up to Mar. 2022 to identify the clinical trials that compared MT alone versus MT with intra-arterial alteplase therapy. STATA 16.0 was used for statistical analysis. The odds ratios (ORs) and 95% confidence intervals (95%CIs) were calculated with a random effect model.

Results

Seven studies involving 1,083 participants were included. The primary outcomes were better functional outcomes, defined as a modified Rankin Scale (mRS) score between 0 and 2 at 90  days, and successful recanalization, defined as a modified thrombolysis in cerebral infarction (mTICI) score  ≥  2b. Compared to MT alone, MT with intra-arterial alteplase did not lead to higher mTICI scores (OR 1.58, 95%CI 0.94 to 2.67, p = 0.085, I2 = 16.8%) but did lead to better mRS (OR 1.37, 95%CI 1.01 to 1.86, p = 0.044). There was no increase in mortality or bleeding events in the overall or subgroup analyses.

Conclusion

MT with intra-arterial alteplase did not improve the recanalization rate but provided better functional outcomes. The intervention did not increase adverse effects in any subgroup at the same time.

Clinical trial registration

http://inplasy.com, identifier INPLASY202240027.

MASTRO I: Meta-Analysis and Systematic Review of thrombectomy stent retriever outcomes: comparing functional, safety and recanalization outcomes between EmboTrap, Solitaire and Trevo in acute ischemic stroke

Aim: Stent-retriever (SR) thrombectomy has demonstrated superior outcomes in patients with acute ischemic stroke compared with medical management alone, but differences among SRs remain unexplored. We conducted a Systematic Review/Meta-Analysis to compare outcomes between three SRs: EmboTrap®, Solitaire™, and Trevo®. Methods: We conducted a PRISMA-compliant Systematic Review among English-language studies published after 2014 in PubMed/MEDLINE that reported SRs in ≥25 patients. Functional and safety outcomes included 90-day modified Rankin scale (mRS 0-2), mortality, symptomatic intracranial hemorrhage (sICH), and embolization to new territory (ENT). Recanalization outcomes included modified thrombolysis in cerebral infarction (mTICI) and first-pass recanalization (FPR). We used a random effects Meta-Analysis to compare outcomes; subgroup and outlier-influencer analysis were performed to explore heterogeneity. Results: Fifty-one articles comprising 9,804 patients were included. EmboTrap had statistically significantly higher rates of mRS 0-2 (57.4%) compared with Trevo (50.0%, p = 0.013) and Solitaire (45.3%, p < 0.001). Compared with Solitaire (20.4%), EmboTrap (11.2%, p < 0.001) and Trevo (14.5%, p = 0.018) had statistically significantly lower mortality. Compared with Solitaire (7.7%), EmboTrap (3.9%, p = 0.028) and Trevo (4.6%, p = 0.049) had statistically significantly lower rates of sICH. There were no significant differences in ENT rates across all three devices (6.0% for EmboTrap, 5.3% for Trevo, and 7.7% for Solitaire, p = 0.518). EmboTrap had numerically higher rates of recanalization; however, no statistically significant differences were found. Conclusion: The results of our Systematic Review/Meta-Analysis suggest that EmboTrap may be associated with significantly improved functional outcomes compared with Solitaire and Trevo. EmboTrap and Trevo may be associated with significantly lower rates of sICH and mortality compared with Solitaire. No significant differences in recanalization and ENT rates were found. These conclusions are tempered by limitations of the analysis including variations in thrombectomy techniques in the field, highlighting the need for multi-arm RCT studies comparing different SR devices to confirm our findings.

Impact of leukoaraiosis in patients with acute ischemic stroke treated with thrombectomy: a post hoc analysis of the DIRECT-MT trial

BACKGROUND

The influence of leukoaraiosis in patients with acute ischemic stroke (AIS) given intra-arterial treatment (IAT) with or without preceding intravenous thrombolysis (IVT) remains unknown.

OBJECTIVE

To assess the clinical and radiological outcomes of IAT in patients with or without leukoaraiosis.

METHODS

Patients of the direct mechanical thrombectomy trial (DIRECT-MT) whose leukoaraiosis grade could be assessed were included. DIRECT-MT was a randomized clinical trial performed in China to assess the effect of direct IAT compared with intravenous thrombolysis plus IAT. We employed the Age-Related White Matter Changes Scale for grading leukoaraiosis (ARWMC, 0 indicates no leukoaraiosis, 1-2 indicates mild-to-moderate leukoaraiosis, and 3 indicates severe leukoaraiosis) based on brain CT. The primary outcome was the score on the modified Rankin Scale (mRS) assessed at 90 days.

RESULTS

There were 656 patients in the trial, 649 patients who were included, with 432 patients without leukoaraiosis, and 217 (33.4%) patients with leukoaraiosis divided into mild-to-moderate (n=139) and severe groups (n=78). Leukoaraiosis was a predictor of a worse mRS score (adjusted OR (aOR)=0.7 (95% CI 0.5 to 0.8)) and higher mortality (aOR=1.4 (1.1 to 1.9)), but it was not associated with symptomatic intracranial hemorrhage (sICH) (aOR=0.9 (0.5 to 1.5)). IVT preceding IAT did not increase sICH risk for patients with no (aOR=1.4 (0.6 to 3.4)), mild-to-moderate (aOR=1.5 (0.3 to 7.8)), or severe (aOR=1.5 (0.1 to 21.3)) leukoaraiosis.

CONCLUSION

Patients with leukoaraiosis with AIS due to large vessel occlusion are at increased risk of a poor functional outcome after IAT but demonstrate similar sICH rates, and IVT preceding IAT does not increase the risk of sICH in Chinese patients with leukoaraiosis.

Endovascular treatment for ischemic stroke patients with and without atrial fibrillation, and the effects of adjunctive pharmacotherapy: a narrative review

INTRODUCTION

Endovascular thrombectomy (EVT) is associated with good clinical outcomes in patients with ischemic stroke, but the impact of EVT on clinical outcomes in patients with ischemic stroke with and without atrial fibrillation (AF), and the effect of adjunctive pharmacological therapies with EVT, remains unclear.

AREAS COVERED

The goal of this narrative review is to provide an overview of studies which have examined: 1) associations between EVT and outcomes for patients following ischemic stroke, 2) associations between EVT and outcomes for patients following ischemic stroke with and without AF , including function, reperfusion, hemorrhage, and mortality, 3) the effect of adjunctive pharmacological therapies peri- and post-thrombectomy, and 4) integration of prehospital care on endovascular treatment outcomes.

EXPERT OPINION

There is little evidence from randomized controlled trials on the effect of AF on stroke outcomes following EVT and the safety and efficacy of AF treatment in the peri-EVT such as tirofiban or Intravenous thrombolysis with Non-vitamin K Antagonist Oral Anticoagulant. The available evidence from observational studies on AF and EVT outcomes is inconsistent, but factors such as procedural EVT devices, the center volume, clinician experience, stroke recognition, and inclusion criteria of studies have all been associated with poorer clinical outcomes. Enhancing the clinical network among prehospital and hospitals will facilitate direct transfer to EVT centers, reducing stroke onset to EVT time and optimizing stroke outcomes.

Intra-arterial thrombolytics during endovascular thrombectomy for acute ischaemic stroke in the MR CLEAN Registry

INTRODUCTION

The efficacy and safety of local intra-arterial (IA) thrombolytics during endovascular thrombectomy (EVT) for large-vessel occlusions is uncertain. We analysed how often IA thrombolytics were administered in the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN) Registry, whether it was associated with improved functional outcome and assessed technical and safety outcomes compared with EVT without IA thrombolytics.

METHODS

In this observational study, we included patients undergoing EVT for an acute ischaemic stroke in the anterior circulation from the MR CLEAN Registry (March 2014-November 2017). The primary endpoint was favourable functional outcome, defined as an modified Rankin Scale score ≤2 at 90 days. Secondary endpoints were reperfusion status, early neurological recovery and symptomatic intracranial haemorrhage (sICH). Subgroup analyses for IA thrombolytics as primary versus adjuvant revascularisation attempt were performed.

RESULTS

Of the 2263 included patients, 95 (4.2%) received IA thrombolytics during EVT. The IA thrombolytics administered were urokinase (median dose, 250 000 IU (IQR, 1 93 750-2 50 000)) or alteplase (median dose, 20 mg (IQR, 12-20)). No association was found between IA thrombolytics and favourable functional outcome (adjusted OR (aOR), 1.16; 95% CI 0.71 to 1.90). Successful reperfusion was less often observed in those patients treated with IA thrombolytics (aOR, 0.57; 95% CI 0.36 to 0.90). The odds of sICH (aOR, 0.82; 95% CI 0.32 to 2.10) and early neurological recovery were comparable between patients treated with and without IA thrombolytics. For primary and adjuvant revascularisation attempts, IA thrombolytics were more often administered for proximal than for distal occlusions. Functional outcomes were comparable for patients receiving IA thrombolytics as a primary versus adjuvant revascularisation attempt.

CONCLUSION

Local IA thrombolytics were rarely used in the MR CLEAN Registry. In the relatively small study sample, no statistical difference was observed between groups in the rate of favourable functional outcome or sICH. Patients whom required and underwent IA thrombolytics were patients less likely to achieve successful reperfusion, probably due to selection bias.

Approaches to and outcomes of intra-arterial tPA in embolectomy for large vessel occlusion

INTRODUCTION

Intra-arterial tissue plasminogen activator (IA tPA) is sometimes used in conjunction with aspiration catheters and stentrievers to achieve recanalization in endovascular thrombectomy (ET) for large vessel occlusion (LVO). Reports of safety and efficacy of this approach are limited by technical heterogeneity and sample size.

METHODS

We retrospectively reviewed a data set of patients undergoing ET for LVO between August 2017 and September 2020 to identify those that received IA tPA. IA tPA usage, timing and dosage was at the discretion of the operative neurosurgeon. We identified three broad categories of IA tPA administration: (1) adjunctive with the first pass; (2) salvage with subsequent passes after first pass achieved incomplete revascularization; and (3) post-thrombectomy residual distal occlusions. Univariate and multivariate logistic regression were performed to test associations with recanalization, hemorrhage, and functional independence.

RESULTS

Among 271 patients, 158 (58%) patients had IA tPA, of which 83 received adjuvant IA tPA, 60 received salvage IA tPA, and 15 received post-thrombectomy IA tPA for distal occlusions. There were no differences in demographics, stroke etiology and premorbid medications between these groups. Patients receiving salvage IA tPA had longer times from groin access to recanalization and more passes, as expected. On multivariate analysis neither adjunctive nor salvage IA tPA was significantly associated with recanalization, post-operative hemorrhage, or functional outcomes. On univariate analysis, patients receiving salvage IA tPA had lower rates of TICI 3 or 2b revascularization (80% vs. 89% adjunctive and 92% no IA tPA, p =  0.003) and higher rates of any postoperative hemorrhage (33% vs. 22% adjunctive and 19% no IA tPA, p =  0.003).

CONCLUSIONS

In this retrospective, single-institution series, IA tPA used adjunctively or as salvage therapy in ET for LVO was not associated with recanalization, post-operative hemorrhage, or functional outcomes, suggesting IA tPA is an available modality that can be utilized in cases of recalcitrant clots.

The End of Tissue-Type Plasminogen Activator's Reign?

Mechanical thrombectomy is a highly effective treatment for acute ischemic stroke caused by large-vessel occlusion in the anterior cerebral circulation, significantly increasing the likelihood of recovery to functional independence. Until recently, whether intravenous thrombolysis before mechanical thrombectomy provided additional benefits to patients with acute ischemic stroke-large-vessel occlusion remained unclear. Given that reperfusion is a key factor for clinical outcome in patients with acute ischemic stroke-large-vessel occlusion and the efficacy of both intravenous thrombolysis and mechanical thrombectomy is time-dependent, achieving complete reperfusion with a single pass should be the primary angiographic goal. However, it remains undetermined whether extending the procedure with additional endovascular attempts or local lytics administration safely leads to higher reperfusion grades and whether there are significant public health and cost implications. Here, we outline the current state of knowledge and research avenues that remain to be explored regarding the consistent therapeutic benefit of intravenous thrombolysis in anterior circulation strokes and the potential place of adjunctive intra-arterial lytics administration, including alternative thrombolytic agent place.

TAB-TICI Score: Successful Recanalization Score After Endovascular Thrombectomy in Acute Stroke

Background and Purpose: Successful reperfusion therapy is supposed to be comprehensive and validated beyond the grade of recanalization. This study aimed to develop a novel scoring system for defining the successful recanalization after endovascular thrombectomy.

Methods: We analyzed the data of consecutive acute stroke patients who were eligible to undergo reperfusion therapy within 24 h of onset and who underwent mechanical thrombectomy using a nationwide multicenter stroke registry. A new score was produced using the predictors which were directly linked to the procedure to evaluate the performance of the thrombectomy procedure.

Results: In total, 446 patients in the training population and 222 patients in the validation population were analyzed. From the potential components of the score, four items were selected: Emergency Room-to-puncture time (T), adjuvant devices used (A), procedural intracranial bleeding (B), and post-thrombectomy reperfusion status [Thrombolysis in Cerebral Infarction (TICI)]. Using these items, the TAB-TICI score was developed, which showed good performance in terms of discriminating early neurological aggravation [AUC 0.73, 95% confidence interval (CI) 0.67–0.78, P < 0.01] and favorable outcomes (AUC 0.69, 95% CI 0.64–0.75, P < 0.01) in the training population. The stability of the TAB-TICI score was confirmed by external validation and sensitivity analyses. The TAB-TICI score and its derived grade of successful recanalization were significantly associated with the volume of thrombectomy cases at each site and in each admission year.

Conclusion: The TAB-TICI score is a valid and easy-to-use tool to more comprehensively define successful recanalization after endovascular thrombectomy in acute stroke patients with large vessel occlusion.

Evidence-Based Updates to Thrombectomy: Targets, New Techniques, and Devices

Endovascular thrombectomy (EVT) has been validated in several randomized controlled trials in recent years for its efficacy in the treatment of acute ischemic strokes (AIS) and is now the standard of care according to international guidelines. However, in about 20% of EVT procedures, recanalization is not achieved, and over 50% of patients who undergo EVT still do not have good functional outcome. In this article, we provide an extensive review of the latest evidence and developments in the field of EVT, with particular focus on the factors that improve patient outcomes. These factors include new and adjunctive techniques such as combination of direct aspiration and stent retriever, intra-arterial urokinase or 2b/3a inhibitors, rescue stenting, as well as novel devices including balloon guide catheters and the newer generations of aspiration catheters and stent retrievers. We also examined the latest notion of using first-pass effect (FPE) as the target to achieve during EVT, which has been associated with an improved functional outcome. While the field of EVT has been rapidly evolving, further research is required in specific AIS patient populations such as those with large ischemic core, late presentation beyond 24 h, posterior circulation strokes, and with distal medium vessel occlusion or tandem lesions to better assess its efficacy and safety.

Local Intra-arterial Thrombolysis during Mechanical Thrombectomy for Refractory Large-Vessel Occlusion: Adjunctive Chemical Enhancer of Thrombectomy

BACKGROUND AND PURPOSE

Data on adjunctive intra-arterial thrombolysis during mechanical thrombectomy for refractory thrombus are sparse. The aim of this study was to evaluate the efficacy and safety of local intra-arterial urokinase as an adjunct to mechanical thrombectomy for refractory large-vessel occlusion.

MATERIALS AND METHODS

We retrospectively evaluated patients with acute ischemic stroke who underwent mechanical thrombectomy for anterior circulation large-vessel occlusion between January 2016 and December 2019. Patients were divided into 2 groups based on the use of intra-arterial urokinase as an adjunctive therapy during mechanical thrombectomy for refractory thrombus: the urokinase and nonurokinase groups. Herein, refractory thrombus was defined as the target occlusion with minimal reperfusion (TICI 0 or 1) despite >3 attempts with conventional mechanical thrombectomy. The baseline characteristics, procedural outcomes, and clinical outcome were compared between the 2 groups.

RESULTS

One hundred fourteen cases of refractory thrombus were identified. A total of 45 and 69 patients were in the urokinase and the nonurokinase groups, respectively. The urokinase group compared with the nonurokinase group showed a higher rate of successful reperfusion (82.2% versus 63.8%, P = .034), with lower procedural times (54 versus 69 minutes, P = .137). The rates of good clinical outcome, distal embolism, and symptomatic intracranial hemorrhage were similar between the 2 groups. The use of intra-arterial urokinase (OR = 3.682; 95% CI, 1.156-11.730; P = .027) was an independent predictor of successful reperfusion.

CONCLUSIONS

The use of local intra-arterial urokinase as an adjunct to mechanical thrombectomy may be an effective and safe method that provides better recanalization than the conventional mechanical thrombectomy for refractory thrombus in patients with embolic large-vessel occlusion.

Thrombolytic strategies for ischemic stroke in the thrombectomy era

Twenty-five years ago, intravenous thrombolysis has revolutionized the care of patients with acute ischemic stroke. Since 2015, randomized clinical trials have demonstrated that mechanical thrombectomy improves functional outcome in stroke patients over intravenous thrombolysis alone. More recently, three randomized clinical trials have suggested that mechanical thrombectomy alone is noninferior to a combined strategy with both intravenous thrombolysis and mechanical thrombectomy. In the present review, we will present the last clinical and preclinical studies on the use of thrombolysis in stroke patients in the modern thrombectomy era. At the cost of a potential increased risk of hemorrhagic transformation, thrombolysis may promote arterial recanalization before thrombectomy, improve the rate of successful recanalization after thrombectomy, and restore microcirculation patency downstream of the main thrombus. Besides, new thrombolytic strategies targeting tissue-type plasminogen activator resistant thrombi are being developed, which could strengthen the beneficial effects of thrombolysis without carrying additional pro-hemorrhagic effects. For instance, tenecteplase has shown improved rate of recanalization compared with tissue-type plasminogen activator (alteplase). Beyond fibrinolysis, DNA- and von Willebrand factor-targeted thrombolytic strategies have shown promising results in experimental models of ischemic stroke. New combined strategies, improved thrombolytics, and dedicated clinical trials in selected patients are eagerly awaited to further improve functional outcome in stroke.

Adjunctive Intra-arterial Thrombolysis in Endovascular Thrombectomy: A Systematic Review and Meta-analysis

OBJECTIVE

To evaluate the safety and efficacy of intra-arterial thrombolysis (IAT) as an adjunct to endovascular thrombectomy (EVT) in ischemic stroke, we performed a systematic review and meta-analysis of the literature.

METHODS

Searches were performed using MEDLINE, Embase, and Cochrane databases for studies that compared EVT with EVT with adjunctive IAT (EVT + IAT). Safety outcomes included symptomatic intracerebral hemorrhage and mortality at 3 months. Efficacy outcomes included successful reperfusion (Thrombolysis in Cerebral Infarction score of 2b-3) and functional independence, defined as a modified Rankin Scale score of 0-2 at 3 months.

RESULTS

Five studies were identified that compared combined EVT + IAT (IA alteplase or urokinase) with EVT only and were included in the random-effects meta-analysis. There were 1693 EVT patients, including 269 patients treated with combined EVT + IAT and 1,424 patients receiving EVT only. Pooled analysis did not demonstrate any differences between EVT + IAT and EVT only in rates of symptomatic intracerebral hemorrhage (odds ratio [OR]: 0.61, 95% confidence interval [CI]: 0.20-1.85; p = 0.78), mortality (OR: 0.77, 95% CI: 0.54-1.10; p = 0.15), or successful reperfusion (OR: 1.05, 95% CI: 0.52-2.15; p = 0.89). There was a higher rate of functional independence in patients treated with EVT + IAT, although this was not statistically significant (OR: 1.34, 95% CI: 1.00-1.80; p = 0.053).

CONCLUSION

Adjunctive IAT appears to be safe. In specific situations, neurointerventionists may be justified in administering small doses of intra-arterial alteplase or urokinase as rescue therapy during EVT.

Factors associated with early reperfusion improvement after intra-arterial fibrinolytics as rescue for mechanical thrombectomy

Objective:

To identify factors associated with early angiographic reperfusion improvement (EARI) following intra-arterial fibrinolytics (IAF) after failed or incomplete mechanical thrombectomy (MT).

Methods:

A subset of patients treated with MT and IAF rescue after incomplete reperfusion included in the INFINITY (INtra-arterial FIbriNolytics In ThrombectomY) multicenter observational registry was analyzed. Multivariable logistic regression was used to identify factors associated with EARI. Heterogeneity of the clinical effect of EARI on functional independence (defined as modified Rankin Score ≤2) was tested with interaction terms.

Results:

A total of 228 patients (median age: 72 years, 44.1% female) received IAF as rescue for failed or incomplete MT and had a post-fibrinolytic angiographic control run available (50.9% EARI). A cardioembolic stroke origin (adjusted odds ratio (aOR) 3.72, 95% confidence interval (CI) 1.39–10.0) and shorter groin puncture to IAF intervals (aOR 0.82, 95% CI 0.71–0.95 per 15-min delay) were associated with EARI, while pre-interventional thrombolysis showed no association (aOR 1.15, 95% CI 0.59–2.26). The clinical benefit of EARI after IAF seemed more pronounced in patients without or only minor early ischemic changes (Alberta Stroke Program Early Computed Tomography Score (ASPECTS) ≥9, aOR 4.00, 95% CI 1.37–11.61) and was absent in patients with moderate to severe ischemic changes (ASPECTS ≤8, aOR 0.94, 95% CI 0.27–3.27, p for interaction: 0.095).

Conclusion:

Early rescue and a cardioembolic stroke origin were associated with more frequent EARI after IAF. The clinical effect of EARI seemed reduced in patients with already established infarcts. If confirmed, these findings can help to inform patient selection and inclusion criteria for randomized-controlled trials evaluating IAF as rescue after MT.

Clinical observation of thrombolytic effect of alteplase combined with butylphthalide in patients with acute anterior circulation cerebral infarction

Objective:

This study aims to evaluate the clinical effect of alteplase combined with butylphthalide in treating patients with acute anterior circulation cerebral infarction.

Methods:

Retrospective study methods were used. Eighty patient cases with acute anterior circulation cerebral infarction treated in Baoding First Central Hospital, China from January 2018 to December 2020 were randomly and averagely divided into two groups. Patients in the two groups were given symptomatic treatment. Patients in the experimental group were treated with alteplase combined with butylphthalide for thrombolytic therapy, whereas patients in the control group were treated with urokinase thrombolytic therapy. The NIHSS score, effective rates and neurological function recovery were analysed one day, seven days and 30 days after treatment were analyzed, respectively. So as the incidence of adverse reactions within seven days after drug adminutesistration.

Results:

The NIHSS scores of the two groups were significantly lower than those before treatment on one day, seven days and 30 days after treatment (experimental group, p=0.00; control group, p=0.02). The experimental group was more significantly lower than the control group (p=0.00). The effective rate of the experimental group was significantly higher than that of the control group (p=0.03), and the recovery rate after treatment was significantly higher than that of the control group (p=0.04). Within one week after treatment, the complication rate was 15% in the experimental group and 20% in the control group but was not significantly different (p=0.56).

Conclusion:

Alteplase combined with butylphthalide is effective and safe in the treatment of acute anterior circulation cerebral infarction without obvious complications.

Intra-Arterial Thrombolysis after Unsuccessful Mechanical Thrombectomy in the STRATIS Registry

BACKGROUND AND PURPOSE

Recent data suggest that intra-arterial thrombolytics may be a safe rescue therapy for patients with acute ischemic stroke after unsuccessful mechanical thrombectomy; however, safety and efficacy remain unclear. Here, we evaluate the use of intra-arterial rtPA as a rescue therapy in the Systematic Evaluation of Patients Treated with Neurothrombectomy Devices for Acute Ischemic Stroke (STRATIS) registry.

MATERIALS AND METHODS

STRATIS was a prospective, multicenter, observational study of patients with acute ischemic stroke with large-vessel occlusions treated with the Solitaire stent retriever as the first-line therapy within 8 hours from symptom onset. Clinical and angiographic outcomes were compared in patients having rescue therapy treated with and without intra-arterial rtPA. Unsuccessful mechanical thrombectomy was defined as any use of rescue therapy.

RESULTS

A total of 212/984 (21.5%) patients received rescue therapy, of which 83 (39.2%) and 129 (60.8%) were in the no intra-arterial rtPA and intra-arterial rtPA groups, respectively. Most occlusions were M1, with 43.4% in the no intra-arterial rtPA group and 55.0% in the intra-arterial rtPA group (P = .12). The median intra-arterial rtPA dose was 4 mg (interquartile range = 2-12 mg). A trend toward higher rates of substantial reperfusion (modified TICI  ≥ 2b) (84.7% versus 73.0%, P = .08), good functional outcome (59.2% versus 46.6%, P = .10), and lower rates of mortality (13.3% versus 23.3%, P = .08) was seen in the intra-arterial rtPA cohort. Rates of symptomatic intracranial hemorrhage did not differ (0% versus 1.6%, P = .54).

CONCLUSIONS

Use of intra-arterial rtPA as a rescue therapy after unsuccessful mechanical thrombectomy was not associated with an increased risk of symptomatic intracranial hemorrhage or mortality. Randomized clinical trials are needed to understand the safety and efficacy of intra-arterial thrombolysis as a rescue therapy after mechanical thrombectomy.

Intra-Arterial Adjunctive Medications for Acute Ischemic Stroke During Mechanical Thrombectomy: A Meta-Analysis

BACKGROUND AND PURPOSE

In patients with acute ischemic stroke with large vessel occlusion, the role of intra-arterial adjunctive medications (IAMs), such as urokinase, tPA (tissue-type plasminogen activator), or glycoprotein IIb/IIIa inhibitors, during mechanical thrombectomy (MT) has not been clearly established. We aim to evaluate the efficacy and safety of concomitant or rescue IAM for acute ischemic stroke with large vessel occlusion patients undergoing MT.

METHODS

We searched Medline, Embase, and Cochrane Stroke Group Trials Register databases from inception until March 13, 2020. We analyzed all studies with patients diagnosed with acute ischemic stroke with large vessel occlusion in the anterior or posterior circulation that provided data for the two treatment arms, (1) MT+IAM and (2) MT only, and also reported on at least one of the following efficacy outcomes, recanalization and 90-day modified Rankin Scale, or safety outcomes, symptomatic intracranial hemorrhage and 90-day mortality. Data were collated in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

Sixteen nonrandomized observational studies with a total of 4581 patients were analyzed. MT only was performed in 3233 (70.6%) patients, while 1348 (29.4%) patients were treated with both MT and IAM. As compared with patients treated with MT alone, patients treated with combination therapy (MT+IAM) had a higher likelihood of achieving good functional outcome (risk ratio, 1.13 [95% CI, 1.03-1.24]) and a lower risk of 90-day mortality (risk ratio, 0.82 [95% CI, 0.72-0.94]). There was no significant difference in successful recanalization (risk ratio, 1.02 [95% CI, 0.99-1.06]) and symptomatic intracranial hemorrhage between the two groups (risk ratio, 1.13 [95% CI, 0.87-1.46]).

CONCLUSIONS

In acute ischemic stroke with large vessel occlusion, the use of IAM together with MT may achieve better functional outcomes and lower mortality rates. Randomized controlled trials are warranted to establish the safety and efficacy of IAM as adjunctive treatment to MT.

Safety and efficacy of intra-arterial fibrinolytics as adjunct to mechanical thrombectomy: a systematic review and meta-analysis of observational data

Background

Achieving the best possible reperfusion is a key determinant of clinical outcome after mechanical thrombectomy (MT). However, data on the safety and efficacy of intra-arterial (IA) fibrinolytics as an adjunct to MT with the intention to improve reperfusion are sparse.

Methods

We performed a PROSPERO-registered (CRD42020149124) systematic review and meta-analysis accessing MEDLINE, PubMed, and Embase from January 1, 2000 to January 1, 2020. A random-effect estimate (Mantel-Haenszel) was computed and summary OR with 95% CI were used as a measure of added IA fibrinolytics versus control on the risk of symptomatic intracranial hemorrhage (sICH) and secondary endpoints (modified Rankin Scale ≤2, mortality at 90 days).

Results

The search identified six observational cohort studies and three observational datasets of MT randomized-controlled trial data reporting on IA fibrinolytics with MT as compared with MT alone, including 2797 patients (405 with additional IA fibrinolytics (100 urokinase (uPA), 305 tissue plasminogen activator (tPA)) and 2392 patients without IA fibrinolytics). Of 405 MT patients treated with additional IA fibrinolytics, 209 (51.6%) received prior intravenous tPA. We did not observe an increased risk of sICH after administration of IA fibrinolytics as adjunct to MT (OR 1.06, 95% CI 0.64 to 1.76), nor excess mortality (0.81, 95% CI 0.60 to 1.08). Although the mode of reporting was heterogeneous, some studies observed improved reperfusion after IA fibrinolytics.

Conclusion

The quality of evidence regarding peri-interventional administration of IA fibrinolytics in MT is low and limited to observational data. In highly selected patients, no increase in sICH was observed, but there is large uncertainty.

The novel GLP-1/GIP dual agonist DA3-CH is more effective than liraglutide in reducing endoplasmic reticulum stress in diabetic rats with cerebral ischemia-reperfusion injury

BACKGROUND AND AIMS

Diabetes is one of the most important risk factors and comorbidities of ischemic stroke. Endoplasmic reticulum stress (ERS) is considered to be the major injury mechanism of ischemic stroke with diabetes. Studies have found that incretin can inhibit ERS in ischemia-reperfusion injury of the liver and heart. We aimed to explore the effects of GLP-1/GIP double agonist DA3-CH and GLP-1 single agonist liraglutide on ERS and apoptosis in diabetic rats with cerebral ischemia-reperfusion injury.

METHODS AND RESULTS

72 Sprague-Dawley (SD) male rats were randomly divided into 4 groups: ① blank group (Sham group, n = 18); model group (Saline group, n = 18); DA3 treatment group (DA3 group, n = 18); liraglutide treatment group (Lir group, n = 18). The Sham group was not given any treatment and was only raised in the same environment as the other groups. The remaining 3 groups used STZ-induced diabetes models. After the successful membrane formation of diabetes, DA3-CH and liraglutide (10 mmol/kg, once-daily for 14 days) were injected intraperitoneally. Thereafter, rats were subjected to middle cerebral artery occlusion followed by 24-h reperfusion. Animals were evaluated for neurologic deficit score, infarct volume, and biomarker analyses of the brain after ischemia. The DA3-CH-treated and liraglutide-treated groups showed significantly reduced scores of neurological dysfunction and cerebral infarction size, and reduced the expression of ERS markers GRP78, CHOP and Caspase-12, and the expression of apoptosis marker bax. Anti-apoptotic markers bcl-2 and neuronal numbers increased significantly.

CONCLUSIONS

DA3-CH and liraglutide have obvious neuroprotective effects in a rat model of cerebral ischemia-reperfusion injury with diabetes, which can reduce the infarct size and the neurological deficit score. Their exert neuroprotective effects in a rat model of cerebral ischemia-reperfusion injury with diabetes by inhibiting endoplasmic reticulum stress and thereby reducing apoptosis. DA3 is better than liraglutide.

Safety and Efficacy of Intra-arterial Urokinase After Failed, Unsuccessful, or Incomplete Mechanical Thrombectomy in Anterior Circulation Large-Vessel Occlusion Stroke

Importance

Achieving complete reperfusion is a key determinant of good outcome in patients treated with mechanical thrombectomy (MT). However, data on treatments geared toward improving reperfusion after incomplete MT are sparse.

Objective

To determine whether administration of intra-arterial urokinase is safe and improves reperfusion after failed or incomplete MT.

Design, Setting, and Participants

This observational cohort study included a consecutive sample of patients treated with second-generation MT from January 1, 2010, through August 4, 2017. Data were collected from the prospective registry of a tertiary care stroke center. Of 1274 patients screened, 69 refused to participate, and 993 met the observational studies inclusion criteria of a large vessel occlusion in the anterior circulation. Data were analyzed from September 1, 2017, through September 20, 2019.

Intervention

One hundred patients received intra-arterial urokinase after failed or incomplete MT using manual microcatheter injections.

Main Outcomes and Measures

Primary safety outcome was the occurrence of symptomatic intracranial hemorrhage (sICH) according to the Prolyse in Acute Cerebral Thromboembolism II criteria. Secondary end points included 90-day mortality and 90-day functional independence (defined as modified Rankin Scale score of ≤2). Efficacy was evaluated angiographically, applying the Thrombolysis in Cerebral Infarction (TICI) scale.

Results

After exclusion of patients with posterior circulation strokes and those treated with intra-arterial thrombolytics only, 993 patients were included in the final analyses (median age, 74.6 [interquartile range, 62.6-82.2] years; 505 [50.9%] women). Additional intra-arterial urokinase was administered in 100 patients (10.1%). The most common reason for administering intra-arterial urokinase was incomplete reperfusion (TICI<3) after MT (53 [53.0%]). After adjusting for baseline characteristics underlying case selection, intra-arterial urokinase was not associated with an increased risk of sICH (adjusted odds ratio [aOR], 0.81; 95% CI, 0.31-2.13) or 90-day mortality (aOR, 0.78; 95% CI, 0.43-1.40). Among 53 cases of partial or near-complete reperfusion and treated with intra-arterial urokinase, 32 (60.4%) had early reperfusion improvement, and 18 of 53 (34.0%) had an improvement in TICI grade. Correspondingly, patients treated with intra-arterial urokinase had higher rates of functional independence after adjusting for the selection bias favoring a priori poor TICI grades in the intra-arterial urokinase group (aOR, 1.93; 95% CI, 1.11-3.37).

Conclusions and Relevance

In selected patients, adjunctive treatment with intra-arterial urokinase during or after MT was safe and improved angiographic reperfusion. Systemic evaluation of this approach in a multicenter prospective registry or a randomized clinical trial seems warranted.

The Chemical Optimization of Cerebral Embolectomy trial: Study protocol

RATIONALE

The potential value of rescue intraarterial thrombolysis in patients with large vessel occlusion stroke treated with mechanical thrombectomy has not been assessed in randomized trials.

AIM

The CHemical OptImization of Cerebral Embolectomy trial aims to establish whether rescue intraarterial thrombolysis is more effective than placebo in improving suboptimal reperfusion scores in patients with large vessel occlusion stroke treated with mechanical thrombectomy.

SAMPLE SIZE ESTIMATES

A sample size of 200 patients allocated 1:1 to intraarterial thrombolysis or intraarterial placebo will have >95% statistical power for achieving the primary outcome (5% in the control versus 60% in the treatment group) for a two-sided (5% alpha, and 5% lost to follow-up).

METHODS AND DESIGN

We conducted a multicenter, randomized, placebo-controlled, double blind, phase 2b trial. Eligible patients are 18 or older with symptomatic large vessel occlusion treated with mechanical thrombectomy resulting in a modified treatment in cerebral ischemia score 2b at end of the procedure. Patients will receive 20-30 min intraarterial infusion of recombinant tissue plasminogen activator or placebo (0.5 mg/ml, maximum dose limit 22.5 mg).

STUDY OUTCOME(S)

The primary outcome is the proportion of patients with an improved modified treatment in cerebral ischemia score 10 min after the end of the study treatment. Secondary outcomes include the shift analysis of the modified Rankin Scale, the infarct expansion ratio, the proportion of excellent outcome (modified Rankin Scale 0-1), the proportion of infarct expansion, and the infarction volume. Mortality and symptomatic intracerebral bleeding will be assessed.

DISCUSSION

The study will provide evidence whether rescue intraarterial thrombolysis improves brain reperfusion in patients with large vessel occlusion stroke and incomplete reperfusion (modified treatment in cerebral ischemia 2b) at the end of mechanical thrombectomy.

Insights Into Intra-arterial Thrombolysis in the Modern Era of Mechanical Thrombectomy

Background and Purpose: The role of intra-arterial (IA) thrombolysis in modern endovascular therapy is not well-understood. Here, we surveyed neurointerventionalists to understand their current clinical practices and opinions of IA thrombolysis in the new era of mechanical thrombectomy (MT).

Method: A 24-question anonymous survey was distributed via email to the members of the Society of Vascular and Interventional Neurology.

Results: One hundred and four responses were included in the analysis. Most respondents were interventional neurologists (76.9%) and had ≥5-years in neuro-interventional practice (80.8%). IA thrombolytics are presently used by 60.6%. Aspiration plus stent-retriever was the most common MT approach used with IA-thrombolysis (66.0%). IA-thrombolysis was used in mainly three approaches: (1) treatment of primary distal occlusions, (2) as rescue after proximal occlusion thrombectomy, and (3) or as adjunct therapy to primary MT approach. The most frequent IA-rtPA dose was 3–10 mg, with 1 mg/min infusion rate (56.6%). 84.9% do not have a standardized protocol for administering IA-rtPA. About half (50.9%) believed there should be no time limit for administering IA lytic if there is a favorable imaging profile, while 30.2% indicated ≤6 h. Most respondents (76.5%) would consider using IA-tenecteplase in a trial setting. Only 12.9% felt there was no role for IA thrombolysis in modern endovascular practice. Respondents with ≥10-years' experience were less supportive of the future of IA lytic (98.0 vs. 76.4%, p = 0.006).

Conclusion: IA-thrombolysis is currently used in clinical practice; however, there is no clear consensus on best practices or criteria for administration. Further studies are needed to define the role of IA-thrombolysis in the context of MT.

Intraarterial Thrombolysis as Rescue Therapy for Large Vessel Occlusions

Background and Purpose—

Mechanical thrombectomy (MT) devices have led to improved reperfusion and clinical outcomes in acute ischemic stroke patients with emergent large vessel occlusions; however, less than one-third of patients achieve complete reperfusion. Use of intraarterial thrombolysis in the context of MT may provide an opportunity to enhance these results. Here, we evaluate the use of intraarterial rtPA (recombinant tissue-type plasminogen activator) as rescue therapy (RT) after failed MT in the North American Solitaire Stent-Retriever Acute Stroke registry.

Methods—

The North American Solitaire Stent-Retriever Acute Stroke registry recruited sites within North America to submit data on acute ischemic stroke patients treated with the Solitaire device. After restricting the population of 354 patients to use of RT and anterior emergent large vessel occlusions, we compared patients who were treated with and without intraarterial rtPA after failed MT.

Results—

A total of 37 and 44 patients was in the intraarterial rtPA RT and the no intraarterial rtPA RT groups, respectively. Revascularization success (modified Thrombolysis in Cerebral Infarction ≥2b) was achieved in more intraarterial rtPA RT patients (61.2% versus 46.6%; P =0.13) with faster times to recanalization (100±85 versus 164±235 minutes; P =0.36) but was not statistically significant. The rate of symptomatic intracranial hemorrhage (13.9% versus 6.8%; P =0.29) and mortality (42.9% versus 44.7%; P =0.87) were similar between the groups. Good functional outcome (modified Rankin Scale score of ≤2) was numerically higher in intraarterial rtPA patients (22.9% versus 18.4%; P =0.64). Further restriction of the RT population to M1 occlusions only and time of onset to groin puncture ≤8 hours, resulted in significantly higher successful revascularization rates in the intraarterial rtPA RT cohort (77.8% versus 38.9%; P =0.02).

Conclusions—

Intraarterial rtPA as RT demonstrated a similar safety and clinical outcome profile, with higher reperfusion rates achieved in patients with M1 occlusions. Prospective studies are needed to delineate the role of intraarterial thrombolysis in MT.