There is provided a device to secure a prosthesis, such as a stent graft, to the internal wall of a body lumen. The device is formed from two elongate elements each comprising a central portion with at least one arm extending therefrom. The central portions of the elements abut. Optionally, the central portions are joined together, optionally by a joining element which can act as a hinge. The terminal end of each arm can be shaped for engagement with the inner surface of the body lumen. The device is reversibly interchangeable between a first folded configuration and a second deployed or open configuration. The device is preferably attached to the sleeve of a stent graft independent of the stents which are preferably ring stents. A stent graft comprising the device is also described.
