An elastomeric fluid-filled prosthetic implant having a shell and a patch providing a reinforced access region on the shell for introduction of manufacturing implements, such as a gel-filling tool. The shell may cover the entire inner face of the patch, or a substantial part thereof, and a peripheral edge of the patch and the shell cooperate to form a flush interface with no sudden surface steps on both interior and exterior surfaces of the implant. The removal of any surface steps eliminates undesirable tactile discontinuities and stress points that may cause the shell wall to wear or may irritate the surrounding tissues. The prosthetic implant may be a breast implant formed of a silicone elastomer. The patch may be the same material or a liquid silicone rubber, but at least has similar material properties such as elastic modulus, durometer and elongation. The patch may include a channel, such as a self-sealing channel, used for introducing silicone to the mold to form the shell, for venting the mold cavity during the mold process, and/or for introducing the silicone gel into the hollow prosthesis. The patch may be combined with a fluid fill valve for manually adjusting the amount of a fluid such as saline within the shell after the mold process.