Delivery systems and methods of implantation for replacement prosthetic heart valves

A method of delivering a replacement prosthetic valve to a previously implanted prosthetic valve comprising an inflow end and an outflow end, the method comprising:

• compressing a replacement prosthetic valve comprising an expandable stent within a first sheath of a delivery system, wherein the delivery system comprises a proximal end and a distal end;
• advancing the distal end of the delivery system and compressed replacement prosthetic valve into a vessel of a patient and toward the outflow end of the previously implanted prosthetic valve until the compressed expandable stent has advanced through the previously implanted prosthetic valve and is positioned past the inflow end of the previously implanted prosthetic valve;
• partially retracting a second sheath of the delivery system toward the proximal end of the delivery system until at least one petal of the delivery system extends from a first end of the second sheath, wherein the at least one petal extends radially relative to the sheath;
• partially withdrawing the delivery system from the vessel of the patient until the at least one petal engages with the inflow end of the previously implanted prosthetic valve;
• and
• retracting the first sheath of the delivery system toward the proximal end of the delivery system to expose the compressed stent and deploy the replacement prosthetic valve.