Method and apparatus for treating vessel wall with UV radiation following angioplasty

Claim 1

A light diffusing optical waveguide assembly adapted to be inserted into a guidewire lumen of an intravascular catheter comprising: (a) an elongated, flexible, tubular metal shaft member having a proximal end, a distal end and a lumen extending therebetween, the tubular metal shaft member having an outer diameter small enough to fit through a working lumen of an intravascular catheter; (b) an optical fiber having a proximal end, a distal end and a longitudinal axis, said optical fiber having an outer diameter allowing it to fit through said lumen of said tubular metal shaft member and a light deflector affixed to the optical fiber in spaced relation to said distal end of said optical fiber said distal end of said optical fiber for deflecting light waves transmitted down said optical fiber at a predetermined angle to said longitudinal axis; (c) a helically wound metal wire affixed to said shaft member at the distal end thereof, said helical wound metal wire having a closed convolutions section extending beyond said distal end of said shaft member and an open convolutions section intermediate said closed section and adjacent said deflector so that light waves deflected from said deflector at the predetermined angle is able to pass between the open convolutions of the helical wound wire in the intermediate open convolutions section.