US Patent 7497873 Intravascular device and method using it

An intravascular device for minimally invasive deployment within a vessel includes a closed loop of flexible material configured to assume a first state in which the closed loop is folded on itself and straightened to allow delivery through a minimally invasive delivery system. When deployed, the loop assumes a second substantially ring-shaped state to become lodged against an inner wall of the vessel. The loop is preferably formed from a shape memory alloy preset to the second state and temporarily deformed to assume said first state during deployment.