Catheter device utilizing a laser beam laterally directed by a high index prism in a liquid medium

A catheter suitable for directing laser energy laterally to a selected site in a body lumen and comprising:

• an elongated, hollow cap at a distal end of the catheter, said cap including a sidewall aperture and defining a confined flow passageway for a liquid medium, said liquid medium flowing through said cap and out through said sidewall aperture;
• a fiber optic including a distal end disposed in said cap and a proximal end for coupling to a laser source;
• and
• a prism positioned at the distal end of the catheter and covered by said cap, said prism being held in a spaced relationship from the fiber optic and positioned in said confined flow passageway to receive a laser beam emitted by said fiber optic and to direct the emitted beam outwardly through said sidewall aperture;
• said prism having a refractive index that is higher than the refractive index of said liquid medium contiguous with the reflective surface of the prism.