Background and objectives: Acute ischemic stroke is a common and serious disease in which the blood supply to the brain is interrupted. This work examines the evidence on new mechanical percutaneous (catheter-based) methods for thrombus elimination compared with systemic and intra-arterial thrombolysis. Mechanical thrombolysis removes, the clot by suction, capture or stent based tools. The aim of this assessment is to present the evidence on benefit and harm for affected patients.

Method: A systematic literature search identified 1270 bibliographic citations, 1018 abstracts were screened based on predefined inclusion criteria and the full text for 128 quotes was requested. The quality of the available evidence on assessing the balance of benefit and harm was evaluated using GRADE methodology. From the evidence, a recommendation was derived.

Results: None of the identified studies met the methodological criteria for proof of efficacy and safety. To summarize the best available evidence and to make trend statements, three single-arm prospective studies with larger numbers (over 100) and 5 smaller case series in the pre-post-design were included. These studies with no direct comparison groups are limited in their validity because they differ in their basic characteristic when compared indirectly with other studies. Second, the investigated mechanical interventions were often mixed with other treatments. Third, their primary endpoints were often not those with the greatest patient-relevance. Finally, the numbers of cases are often very small. Two studies (with study limitations and a low number of cases) on stent-based systems show an indication of a good balance of benefit and harm. The three studies with larger sample sizes with a (for the reasons stated above) problematic indirect comparison to intra-arterial lysis indicate no better benefit-harm balance.

Conclusion and Recommendation: The existing evidence is not sufficient to assess safety and efficacy of mechanical intervention in comparison to conventional stroke care. A renewed evaluation at a later date is recommended.