We assessed in vivo the mode of delivery, short-term patency and cellular response to a prototype endovascular stent. The stent is designed for delivery through a modified microcatheter and is retrievable with detachment from a delivery wire effected by electrolysis. We successfully deployed 12 stents in a range of sizes from 3-4 mm in straight and angled arteries of pigs. At control angiography 3 and 6 weeks later, nine arteries were patent, two occluded and one narrowed; patency was not related to vessel or stent size. The device shows promise as a stent for intracranial arteries since it can be delivered through microcatheters small enough for intracranial navigation and provides the operator with greater control than currently available self- or balloon-expanded stents.