A method is disclosed for the delivery of therapeutic agents into tissues,
blood vessels, and body ducts of the human body. A novel catheter enables
controlled directing of emitted drug delivery to assist control of drug
dwell time in targeted areas. One coaxial catheter embodiment provides
capability for locating an outer lumen of the system into the target
region, with localization of said outer lumen carried out by use of
appropriate medical imaging modalities. In one embodiment, an inner lumen
of the catheter means is primed with the agent to be delivered, and
recirculated flow of the agent through pluralities of appropriately
positioned port holes on the two lumens then occurs via one or more
active and/or passive flow driving and guiding techniques intrinsic to
the design of the coaxial catheter system. Another coaxial catheter
embodiment carries and emits agent in an outer cannula and recaptures
agent plus liquid or fluids in the body (such as blood, bile, serum,
stable (non-flowing) liquid or kinetic liquid) in an inner cannula.