Methods and devices are disclosed for the in-vivo creation and maintenance of contiguous fluid passages in tissue through the use of tissue buttressing portions with interrupted perimeter walls. These portions can be formed from hollow fiber or extruded components. One end of the tissue-buttressing portion is connected to a hollow tube, which may be connected to a fluid source. The other end of the buttressing portion may be attached to a needle or other device suitable for the penetration of tissue and the formation of passageways in tissue. When the device is installed in tissue, the hollow tube portion of the device is passed part way through the surface of the patient and serves as the conduit for the transfer of fluid to the implanted tissue-buttressing portion of the device. The presence of the buttressing portion within the tissue causes a bridging of the local tissue thereby forming an infusion passage between the external surface of the buttressing portion and the abutting tissue. Therapeutic fluids may be passed from the hollow fiber conduit of the device and though the infusion passage created by the buttressing portion of the device and the surrounding tissue.