Infusion balloon catheter

A balloon catheter which comprises a catheter shaft and a balloon carried on said catheter shaft, a lumen defined by said catheter shaft which communicates between a space located within said balloon and a proximal end portion of said catheter shaft, said balloon comprising a plurality of holes of a size to permit medication delivered through said lumen to pass outwardly through said holes, said balloon having an outer surface and carrying on said outer surface a tubular, substantially hydrophilic, microporous membrane covering said holes to break up streams of flowing medication, said balloon defining a central, generally cylindrical portion and tapered end portions having minimum diameter ends adhered to the catheter shaft, said tubular, microporous membrane being carried by the cylindrical portion of said balloon and spaced from the tapered end portions, the micropores of said membrane being essentially from 0.4 to 3 microns in diameter, the holes of said balloon being essentially from 5 to 100 microns in diameter.