An implant delivery system (60, 360) for delivering a sheet-like implant, the implant delivery system comprising: a delivery shaft having a proximal end and a distal end; an implant expander (120, 320, 520, 720), mounted to the distal end of the delivery shaft, including a central portion (122, 322, 522, 722) and a plurality of leg portions (122, 322, 522, 722) radiating from the central portion (122, 322, 522, 722), the implant expander (120, 320, 520, 720) being evertable between an unstressed configuration in which a distal surface of the implant expander (120, 320, 520, 720) defines a concave surface and a first compact configuration in which the distal surface of the implant expander (120, 320, 520, 720) defines a convex surface, the implant expander (120, 320, 520, 720) having a first lateral extent when the implant expander is free to assume the unstressed configuration; a sheath (102, 302) defining a lumen (108, 308) having a lumen diameter, at least a portion of the delivery shaft slidably disposed in the lumen (108, 308), the lumen diameter being smaller than the first lateral extent of the implant expander (120, 320, 520, 720) so that the sheath (102, 302) holds the implant expander (120, 320, 520, 720) in the first compact configuration when slidably disposed therein; and a sheet-like implant overlaying at least a portion of the distal surface of the implant expander (120, 320, 520, 720) with portions of the sheet-like implant extending between the leg portions (124, 324, 524, 724) of the implant expander (120, 320, 520, 720) and the sheath (102, 302), wherein a free end of each leg portion (124, 324, 524, 724) is disposed distally of the central portion (122, 322, 522, 722) when the implant expander (120, 320, 520, 720) is assuming the unstressed configuration wherein the free end of each leg portion (124, 324, 524, 724) is disposed proximally of the central portion (122, 322, 522, 722) when the implant expander (120, 320, 520, 720) is assuming the first compact configuration, characterised in that the implant expander (120, 320, 520, 720) has a second compact configuration, and in that the free end of each leg portion (124, 324, 524, 724) is disposed distally of the central portion (122, 322, 522, 722) when the implant expander (120, 320, 520, 720) is assuming the second compact configuration. a delivery shaft having a proximal end and a distal end; an implant expander (120, 320, 520, 720), mounted to the distal end of the delivery shaft, including a central portion (122, 322, 522, 722) and a plurality of leg portions (122, 322, 522, 722) radiating from the central portion (122, 322, 522, 722), the implant expander (120, 320, 520, 720) being evertable between an unstressed configuration in which a distal surface of the implant expander (120, 320, 520, 720) defines a concave surface and a first compact configuration in which the distal surface of the implant expander (120, 320, 520, 720) defines a convex surface, the implant expander (120, 320, 520, 720) having a first lateral extent when the implant expander is free to assume the unstressed configuration; a sheath (102, 302) defining a lumen (108, 308) having a lumen diameter, at least a portion of the delivery shaft slidably disposed in the lumen (108, 308), the lumen diameter being smaller than the first lateral extent of the implant expander (120, 320, 520, 720) so that the sheath (102, 302) holds the implant expander (120, 320, 520, 720) in the first compact configuration when slidably disposed therein; and a sheet-like implant overlaying at least a portion of the distal surface of the implant expander (120, 320, 520, 720) with portions of the sheet-like implant extending between the leg portions (124, 324, 524, 724) of the implant expander (120, 320, 520, 720) and the sheath (102, 302), wherein a free end of each leg portion (124, 324, 524, 724) is disposed distally of the central portion (122, 322, 522, 722) when the implant expander (120, 320, 520, 720) is assuming the unstressed configuration wherein the free end of each leg portion (124, 324, 524, 724) is disposed proximally of the central portion (122, 322, 522, 722) when the implant expander (120, 320, 520, 720) is assuming the first compact configuration, characterised in that the implant expander (120, 320, 520, 720) has a second compact configuration, and in that the free end of each leg portion (124, 324, 524, 724) is disposed distally of the central portion (122, 322, 522, 722) when the implant expander (120, 320, 520, 720) is assuming the second compact configuration.