other suitable prosthesis material the inner stent structure 8 includes a generally annular circumferential support band and further includes a number of radially projecting arms or anchor hooks 9 extending therefrom the anchor hooks or arms 9 are illustrated as bare wires but in practice applicant contemplates that they may be coated or preferably are covered by a membrane e g the ptfe u201c onionskin u201d membrane commonly used as a wrap or reinforcement and or by other material similar to layer 5 or having some porosity compliance or suitable mechanical or biological properties to provide continuity with the main tubular layers of the graft as well a certain amount of tissue compatibility and sealing as described further below in addition to the stent and anchoring structures 8 9 at the distal end of the graft the same stent structure or one or more separate and additional stents or stent rings may extend to or be placed along the intermediate or proximal length of the graft to maintain its shape fig2 illustrates the graft 10 of fig1 in a side view showing the arms 9 collapsed inwardly against the cylindrical body of the graft as discussed further below this is the normal.