Medtronic's most recent acquistion target was Lazarus Effect, a maker of stroke diagnostic devices. After obtaining European approval, Lazarus Effect is working to get U.S. approval for the ReCover brain blot clot removal device, which works with Medtronic 's Solitaire stent that can be deployed in the brain to scoop out vessel-blocking clots that cause acute ischemic stroke. ReCover removes clots from the brain using a "novel nitinol 'mesh cover' that folds over a stent retriever device during clot retrieval and 'candy wraps' the stent with the clot inside." The acquisition follows the move by the American Heart Association earlier this year to publish new industry guidelines that recommend using devices like the Solitaire in addition to clot-busting drugs in a subset of patients with dangerous strokes. More than 240,000 Americans with acute strokes would be eligible for such a treatment, yet only 13,000 procedures were done in the U.S. last year. A recent randomized clinical trial found that clot particles that were lost while using uncovered retrievers led to ischemic stroke in a new region of the brain 5.6% of the time, vs. 0.4% in the control group. A news release at the time said Lazarus’ technology would disrupt the market for these stent-thrombectomy procedures, partly because the device could be used in combination with a variety of different stent retrievers available in Europe. After Medtronic's $50b purchase of Covidien earlier in 2015, it moved the combined companies’ legal address to Ireland, generating tax savings for Medtronic and giving it greater to invest its overseas cash in U.S. companies without generating repatriation taxes. Since then, Medtronic has acquired seven other companies, most of them device makers based in the U.S. Although several of the deals came with undisclosed terms, Medtronic has spent at least $688m. Medtronic is paying $100m for Lazarus Effect.