Stent-graft prosthesis with pressure relief ports

A stent-graft prosthesis comprising:

• a graft material having a tubular construction, the graft material including a proximal end, a distal end, and a graft lumen extending between the proximal end and the distal end;
• a frame coupled to the graft material;
• a port disposed between the proximal end and the distal end of the graft material, wherein the port enables blood flow from within the graft lumen to exit the graft lumen;
• and
• a port closing stent disposed within the graft lumen, wherein the port closing stent includes a first longitudinal edge attached to an inner surface of the graft material and a second longitudinal edge opposite the first longitudinal edge, where the second longitudinal edge defines a circumference, and wherein none of the circumference of the second longitudinal edge is attached to the graft material,
• wherein the port closing stent includes a first configuration wherein the second longitudinal edge of the port closing stent is spaced radially inward of the graft material and the port so as to permit blood flow from the graft lumen through the port and a second configuration wherein the second longitudinal edge of the port closing stent blocks flow from the graft lumen through the port.