A self-closing device for implantation within a patient's body includes base material including an inner surface area for securing the base material to a tissue structure, and a plurality of support elements surrounding or embedded in the base material. The support elements are separable laterally within a plane of the base material to accommodate creating an opening through the base material for receiving one or more instruments through the base material, and biased to return laterally towards a relaxed state for self-closing the opening after removing the one or more instruments. The device may be provided as a patch or integrally attached to a tubular graft or in various shapes.