A medical device for insertion into a bodily vessel to treat an aneurysm (201), the device comprising: a mechanically expandable device (202) expandable from a first position to a second position, said mechanically expandable device (202) is expanded radially outwardly to the second position such that the exterior surface of said mechanically expandable (202) engages with the inner surface of the vessel so as to maintain a fluid pathway through said vessel and a membrane (203) expandable from a first position to a second position in response to expansion of said mechanically expandable device (202), said membrane (203) obstructing blood circulation to the aneurysm (201) when expanded to the second position, and at least a portion of the membrane (203) is secured to the mechanically expandable device (202) to maintain the position of the membrane (203) relative to the mechanically expandable device (202) when expanded to the second position.