A device (10) for the delivery of an agent to a site in a patient's body at which tissue is to be treated comprises a delivery conduit (12) having a proximal end attachable to a source (14) of the agent. An emitter structure (16) is arranged at a distal end of the delivery conduit (12), the emitter structure (16) defining a plurality of spaced discharge apertures (18) through which the agent is delivered to the site. The emitter structure (16) is configured to promote diffuse distribution of the agent throughout the tissue at the site in the patient's body.
