The start of a new era for stroke treatment: mechanical thrombectomy devices

Stroke is a major cause of mortality in the U.K. accounting for 53,000 deaths every year. There are few options for the treatment of acute ischemic stroke and recombinant tissue plasminogen activator (rt-PA) remains the only approved and currently available thrombolytic therapy given within the first 3 hours after symptom onset. Mechanical thrombectomy is a promising new treatment modality for patients who are ineligible for or failing intravenous rt-PA, or presenting beyond the narrow 3-hour therapeutic window, and emerged with the development of the Merci retrieval system. A number of devices are now available and can be divided into two major subgroups according to their mode of action. Those using a proximal approach such as aspiration devices (Penumbra system) act by applying a vacuum to the proximal aspect of the thrombus whereas distal devices (Merci retrieval system, Phenox clot retriever, and Catch device) such as coil-like and basket-like devices are advanced through the thrombus thereby contacting its distal aspect. In this review, we discuss the procedure and technique, as well as evidence associated with four mechanical retrieval systems currently available: the Merci Retriever System, the Penumbra system, the Catch device, and the Phenox clot retriever. We also consider potentialnovel approaches for stroke treatment including waterjet thrombectomy and laser recanalization.