Stent graft with internal tunnels and fenestrations and methods of use

A method of implanting a thoraco-abdominal branch graft prosthesis, comprising the steps of:

• a) delivering a thoraco-abdominal branch graft prosthesis through a blood vessel to a thoraco-abdominal aneurysm site in a patient, the thoraco-abdominal branch graft prosthesis including
• i) a main graft component having a luminal wall defining, at least in part, an open proximal end, an open distal end opposite the open proximal end, a main lumen extending from the open proximal end to the open distal end, and at least one main graft wall fenestration, wherein the open distal end of the main graft component is tapered and has a smaller diameter than the proximal end of the main graft component;
• and
• ii) at least one tunnel graft component having a wall defining an open proximal end, an open distal end opposite the open proximal end, a lumen extending from the tunnel graft proximal end to the tunnel graft distal end, and at least one tunnel graft fenestration in the tunnel graft wall, wherein the tunnel graft component is within the main graft lumen and a major longitudinal axis of the tunnel graft lumen is substantially aligned with a major longitudinal axis-of the main lumen, and wherein the wall of the tunnel graft component is fixed to the wall of the main graft component, whereby the fenestration of the tunnel graft wall is aligned with the fenestration of the main graft wall,
• wherein the at least one main graft wall fenestration is substantially aligned with at least one branch vessel of the patient at the thoraco-abdominal aneurysm site;
• b) inserting at least one branch prosthesis through the at least one main graft wall fenestration and the at least one tunnel graft fenestration within the lumen of the at least one tunnel graft component, the at least one branch prosthesis having an open distal end and an open proximal end;
• and
• c) inserting one of the distal end or the proximal end of the at least one branch prosthesis into at least one branch vessel of the patient at the thoraco-abdominal aneurysm site.