Method and apparatus for local delivery of therapeutic agent

DETAILED DESCRIPTION The present invention provides a therapeutic substance delivery device and method which provides for the positioning of at least one delivery conduit in close proximity with the intended treatment site independent of the expansion of an inflatable member such as a balloon.
The embodiments of the present invention utilize at least one flexible conduit which can be buckled to form a bowed configuration to place its perfusion ports in close proximity to tissue such as a vessel to be treated.
The delivery device may be used with or without a balloon angioplasty catheter to provide immediate delivery of a therapeutic substance after an angioplasty procedure.
It is noted that throughout the discussion of the present invention that proximal refers to the direction along the delivery path of the device leading to the exterior of the patient and distal refers to the path along the delivery device leading to the interior of the patient.
In one embodiment of the present invention, one or more flexible tubes or conduits are arranged to extend parallel with a shaft such as a wire or flexible hypotube.
The distal ends of the conduits are joined to the distal end of the shaft in an end cap while the more proximal regions of the shaft and conduits are held in parallel relationship to one another within a multi-lumen outer catheter, each of the conduits and shaft slidably contained within a separate lumen of the catheter.
The proximal ends of the conduits may be joined to one or more sources of therapeutic substances which are intended to be delivered to the treatment site.
Distal portions of the conduits not contained in the outer catheter have perfusion ports along their length and can bow radially outward under longitudinally compressive loading applied by moving the shaft relative to the conduits.
The assembly may be navigated through the vessels to the treatment site much as would be a conventional catheter.
During delivery, the conduits may be held in tension to extend substantially parallel to the longitudinal axis of the shaft along their entire length