Apparatus and method deliver a prosthesis into a hollow body organ or blood vessel. The systems and methods make use of a catheter. A carrier on the distal end of the catheter is sized and configured to carry the prosthesis. A release mechanism and an enclosure mechanism on the distal end are operable to retain and enclose the prosthesis on the carrier. The release mechanism and the enclosure mechanism are also operable to selectively expose and release the prosthesis from the carrier for deployment in the hollow body organ or blood vessel.