Elsevier

World Neurosurgery

Volume 108, December 2017, Pages 850-858.e2
World Neurosurgery

Original Article
Endovascular Thrombectomy Alone versus Combined with Intravenous Thrombolysis

https://doi.org/10.1016/j.wneu.2017.08.040Get rights and content

Background

To date, no randomized trial has directly addressed the question of whether intravenous (IV) tissue plasminogen activator (tPA) improves outcomes in IV tPA-eligible patients who will eventually undergo endovascular therapy (EVT), or whether a direct EVT strategy is equally effective. We performed a systematic review and meta-analysis to compare the efficacy and safety of direct EVT versus endovascular treatment with IV tPA (EVT+IV tPA) in adults with acute ischemic stroke.

Methods

We performed electronic searches of 6 databases from their inception to January 2017. Data were extracted and analyzed according to predefined clinical endpoints.

Results

Twelve comparative studies, comprising 1275 patients in the EVT-only arm and 1340 patients in the combined EVT+IV tPA arm, were included. The rates of good functional outcomes (modified Rankin Scale score ≤2) and 90-day mortality were not statistically significantly different between the EVT and EVT+IV tPA arms (44% vs. 48%; odds ratio [OR], 0.80; 95% confidence interval [CI], 0.64–1.002; P = 0.052 and 20.4% vs. 19.4%, OR 1.19; 95% CI, 0.83–1.71; P = 0.34, respectively). The rate of symptomatic intracranial hemorrhage also was not significantly different between the EVT and EVT+IV tPA arms (3.7% vs. 3.8%; OR, 0.98; 95% CI, 0.65–1.48; P = 0.91). There were no between-group differences in the rates of other complications.

Conclusions

No significant differences between the 2 groups were found in terms of favorable functional outcome, mortality rate, or complications based on contemporary endovascular therapies.

Introduction

Numerous studies have demonstrated the benefits of intravenous (IV) tissue plasminogen activator (tPA) for treating acute ischemic stroke, regardless of stroke subtype.1 The aim of IV tPA therapy is to recanalize the affected blood vessel and establish reperfusion.2 However, in large vessel occlusions, the efficacy of reperfusion using IV tPA alone has been suboptimal, with recanalization rates as low as 6% for occlusion of the terminal internal carotid artery.3, 4

Recently, the publication of multiple randomized controlled trials5, 6, 7, 8 convincingly demonstrated that the addition of endovascular thrombectomy (EVT) to IV tPA improved outcomes after acute ischemic stroke caused by large vessel occlusions. The design of these trials was such that the majority of patients who were treated with mechanical thrombectomy also received IV thrombolysis. However, the number of patients in these trials who did not receive previous IV tPA was very small, and thus whether previous IV tPA helps or harms patients with large vessel occlusion stroke remains unclear. Despite the potential benefits of IV tPA, its use also carries a potential risk of hemorrhagic complications,9, 10 distal embolization due to fragmentation of the thrombus, delay in subsequent EVT, and high associated costs.11

No randomized trial has directly addressed the question of whether IV tPA improves the outcomes of IV tPA–eligible patients who will eventually undergo EVT, or whether a direct EVT strategy will be equally effective. We conducted a systematic review and meta-analysis to compare the efficacy and safety of direct EVT alone versus EVT with IV tPA in adults with acute ischemic stroke.

Section snippets

Guidance

The methods and guidelines of this systematic review followed PRISMA guidelines.12, 13 We included prospective and retrospective comparative studies reporting the efficacy and safety of mechanical thrombectomy alone or combined thrombectomy with IV tPA, independent of the device used, for treating ischemic stroke in adults age ≥18 years. When institutions published duplicate studies with accumulating numbers of patients or increased durations of follow-up, only the most complete reports were

Study Selection

We identified a total of 1261 references through 6 electronic database searches (Figure 1). Although 3 randomized controlled trials6, 7 stratified results according to whether or not bridging IV tPA was administered, outcomes were reported as ORs compared with medical therapy alone. The raw data for patients in the EVT and EVT+IV tPA subgroups could not be derived, and thus these studies were excluded from the present analysis. After applying our selection criteria, we selected 12 comparative

Discussion

Despite recent randomized trials demonstrating the benefits of EVT in patients with acute anterior circulation stroke with proximal vessel occlusion,5, 6, 7, 8 whether there is any benefit to providing IV tPA treatment before EVT in this population remains unclear. In 3 of the published randomized trials comparing EVT with best medical therapy,6, 7 subgroup analysis was attempted to identify any statistically heterogeneity in treatment effect size in patients who received mechanical EVT alone

Conclusion

This meta-analysis is the first to pool direct comparative studies of patients receiving EVT alone versus those receiving EVT+IV tPA. Although we identified no statistically significant differences in favorable functional outcome, mortality rate, or complications, including symptomatic intracerebral hemorrhage, between the 2 groups, we did find a trend toward improved functional outcome in the EVT+IV tPA cohort. Further studies with larger sample sizes are warranted.

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      In our study, the use of IVT previous to MT was not associated with better outcome at 90 days or better NIHSS at 24H after stroke, when compared to the use of MT alone. These results are in line with previous meta-analyses that found no significant differences in functional outcome after mechanical thrombectomy alone versus combined therapy with previous IVT.25,26 Also, a recently published trial comparing endovascular thrombectomy with or without intravenous Alteplase in acute stroke showed no benefit in the use of thrombolysis previous to MT regarding functional outcome.27

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    Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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