Laser method and apparatus for the recanalization of vessels and the treatment of other cardiac conditions

Apparatus for treating cardiac conditions with laser radiation comprising a catheter adapted to be inserted into a blood vessel and threaded through the blood vessel to a region to be treated, the catheter comprising a tubular body having a window of laser radiation transparent material formed in a sidewell thereof;

• an optical fiber for guiding a laser beam disposed within the catheter, the optical fiber having an end terminating adjacent to said window;
• and lens means on the end of the optical fiber for dispersing a laser beam guided by the optical fiber sideways outwardly through said window for treating tissue adjacent to the window and wherein said window comprises a closed tubular section of said transparent material which is coaxially disposed between a first catheter body section and a second catheter body section, said optical fiber entering the closed tubular section and terminating therein and wherein said closed tubular section has a cylindrical inner surface which is mirrored except for a part thereof which forms said window so as to reflect the laser beam from the optical fiber outwardly through the window.