Catheter-based endovascular treatment of acute ischemic stroke has been around for several years – this is a nice, concise review of the published literature regarding their use.
The abstract sounds a little more favorably skewed than the actual content of the article – their discussion is appropriately skeptical regarding the efficacy and applicability of this particular treatment modality. It is certainly true that restoring flow to affected regions in stroke is advantageous, and the theory behind the use of these devices is to mechanically ensure open vessels in situations where systemic thrombolysis may not be efficacious and the disability is likely to be profound.
The problem is, there really isn’t any “evidence” in this article. The published literature on this topic is primarily retrospective cohort/case-reports by industry-affiliated inventors of these devices and, even despite this bias, that literature tends to report unacceptable levels of procedural complications while trying desperately to show benefit.
Regardless, as the authors mention, there are many studies of MERCI and Penumbra ongoing – slowly chasing that inexorable statistical probability of finally performing enough studies that, by chance, one of them will be favorable enough upon which to base widespread marketing efforts.
“Neurothrombectomy devices for the treatment of acute ischemic stroke: state of the evidence”
http://www.ncbi.nlm.nih.gov/pubmed/21242342