Abstract: Phototherapeutic instruments are disclosed for providing substantially uniform energy distribution to a major portion of an area exposed during phototherapy. These instruments include an element for directing radiation toward the walls of a lumen and a device for centering the radiation directing element within the lumen. The instruments also allow the flow of blood, therapeutic fluid, or air past the exposure site. The instruments are particularly useful as part of a fiber optic-based medical laser system for photodynamic therapy within the bronchia of the lung, blood vessels or other liquid-filled lumens.

Abstract: Phototherapeutic instruments are disclosed having integral stopper devices which limit the penetration of an optical fiber during tissue penetrating phototherapy. In one preferred embodiment, a fluted outer sheath is disposed about an internal optical fiber. The fluted sheath is configured to expand during penetration of the optical fiber into a patient's tissue. As the fluted elements expand, the present a much larger cross-sectional area which resists further penetration of the instrument beyond a predetermined desirable distance. The invention is useful in limiting an optically-transmissive fiber's penetration and, thereby, reduce the possibility of perforation of a body lumen or organ. The invention is particularly useful in placing a ablative laser radiation device into the ventricle of the heart when performing arrhythmia-correcting laser ablative procedures or when revascularizing the heart percutaneously.