A catheter (250) for delivering a fluid to an anatomical region, comprising an elongate tubular catheter body (254) defining a lumen (268), a distal end (262) of said lumen being closed, a portion of said catheter body having a plurality of openings (266) extending through a side wall of said catheter body thereby defining an infusion section of said catheter； a tubular sheath (252) constructed from a porous material, said tubular sheath being positioned over said infusion section and extending at least a length of said infusion section, said tubular sheath and said catheter body being configured such that fluid within said lumen must pass through said tubular sheath to exit said catheter； wherein a pore size of said porous material is less than about 0.5 microns.
