A sheath for retaining a prosthesis for use in repair of a damaged portion of a body vessel during an open surgical procedure. The prosthesis is of a type having a constricted condition for delivery to the damaged vessel portion and an expanded condition upon deployment from the sheath. The sheath includes a generally cylindrical body having a distal end portion, a proximal end portion, a passageway extending therethrough, and an elongated tab member at the proximal end portion. The tab member is positionable along the generally cylindrical body for initiating the splitting of the generally cylindrical body from the distal end portion of the sheath body toward the proximal end portion.
