A medical device, comprising: a mesh prosthesis 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 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 to prevent relative rotational movement between the resilient deployment structure and the mesh prosthesis . a mesh prosthesis 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 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 to prevent relative rotational movement between the resilient deployment structure and the mesh prosthesis . <EOS>