A tissue prosthesis insertion system includes a first assembly comprising a plurality of nested tubes, one of the tubes being a carrier tube which, in use, receives a component of a tissue prosthesis at a distal end of the carrier tube. A magnetic mount is carried at a proximal end of the first assembly. A second assembly is removably attachable to the first assembly. An attachment device is carried at a distal end of the second assembly, the attachment device being responsive to the magnetic mount of the first assembly, the magnetic mount and the attachment device carrying complementary engaging formations to facilitate hermetic sealing between the magnetic mount and the attachment device.
