An expandable implant includes an implant shell having an opening and a valve assembly closing the opening. The valve assembly has a first elastic patch, and a second elastic patch juxtaposed with the first elastic patch. A major face of the first elastic patch opposes a major face of the second elastic patch, and the opposing major faces have a bonded area in which the opposing faces are joined together and an unbonded area in which the opposing faces are not joined together and are free to move away from one another. A plug is disposed between the opposing major faces. A first opening extends through the first elastic patch and a second opening extends through the second elastic patch. The first and second openings are offset from one another and the unbonded area defines an elongated channel extending between the first and second openings.
