A therapeutic device to release a therapeutic agent comprises a porous structure coupled to a container comprising a reservoir. The reservoir comprises a volume sized to release therapeutic amounts of the therapeutic agent for an extended time when coupled to the porous structure and implanted in the patient. The porous structure may comprise a first side coupled to the reservoir and a second side to couple to the patient to release the therapeutic agent. A plurality of interconnecting channels can extend from the first side to the second side so as to connect a first a plurality of openings on the first side with a second plurality of openings on the second side.