A medical device, comprising: a mesh prosthesis (106,106A, 106B, 106C, 106D) having: a first layer of mesh affixed to a second layer of mesh proximate to a perimeter area thereof; an enclosure defined between the first layer of mesh and the second layer of mesh and extending inwardly from the perimeter area of the mesh prosthesis; an opening in the first layer of mesh passing through the first layer of mesh to the enclosure; and a resilient deployment structure removably disposed within the enclosure and extending toward the perimeter area, the resilient deployment structure having an elasticity that generates a resilient deployment force for urging the mesh prosthesis to a deployed configuration from a non-deployed configuration; wherein the resilient deployment structure comprises a separation line disposed in the resilient deployment structure extending in a generally serpentine shape from a central portion of the resilient deployment structure to the perimeter of the resilient deployment structure; and characterised in that the medical device comprises a fixation guide template defining a plurality of guide pockets (104,104A, 104B, 104C, 104D, 104E) within the enclosure; and a plurality of shield projections spaced from each other about a perimeter of the resilient deployment structure and extending outwardly from the perimeter of the resilient deployment structure, wherein each of the shield projections is engaged within a corresponding one of the guide pockets (104, 104A, 104B, 104C, 104D, 104E) to prevent relative rotational movement between the resilient deployment structure and the mesh prosthesis (106,106A, 106B, 106C, 106D). a mesh prosthesis (106,106A, 106B, 106C, 106D) having: a first layer of mesh affixed to a second layer of mesh proximate to a perimeter area thereof; an enclosure defined between the first layer of mesh and the second layer of mesh and extending inwardly from the perimeter area of the mesh prosthesis; an opening in the first layer of mesh passing through the first layer of mesh to the enclosure; and a first layer of mesh affixed to a second layer of mesh proximate to a perimeter area thereof; an enclosure defined between the first layer of mesh and the second layer of mesh and extending inwardly from the perimeter area of the mesh prosthesis; an opening in the first layer of mesh passing through the first layer of mesh to the enclosure; and a resilient deployment structure removably disposed within the enclosure and extending toward the perimeter area, the resilient deployment structure having an elasticity that generates a resilient deployment force for urging the mesh prosthesis to a deployed configuration from a non-deployed configuration; wherein the resilient deployment structure comprises a separation line disposed in the resilient deployment structure extending in a generally serpentine shape from a central portion of the resilient deployment structure to the perimeter of the resilient deployment structure; and characterised in that the medical device comprises a fixation guide template defining a plurality of guide pockets (104,104A, 104B, 104C, 104D, 104E) within the enclosure; and a plurality of shield projections spaced from each other about a perimeter of the resilient deployment structure and extending outwardly from the perimeter of the resilient deployment structure, wherein each of the shield projections is engaged within a corresponding one of the guide pockets (104, 104A, 104B, 104C, 104D, 104E) to prevent relative rotational movement between the resilient deployment structure and the mesh prosthesis (106,106A, 106B, 106C, 106D).