LASER FRAGMENTATION OF BILIARY STONES

BILIARY STONE DISEASE AFFECTS OVER 16 MILLION PEOPLE IN THE UNITED STATES. APPROXIMATELY 1 MILLION NEW CASES OF CHOLELTHIASIS DEVELOP EACH YEAR, AND SURGICAL INTERVENTION WAS REQUIRED IN 554,000 PROCEDURES IN 1984, A 3% INCREASE FROM 1983. THE AVERAGE LENGTH OF HOSPITALIZATION FOR THESE PATIENTS IS BETWEEN 9 AND 16 DAYS. CANDELA PROPOSES TO DEVELOP A LASER TECHNIQUE FOR FRAGMENTATION OF BILIARY STONES TO FACILITATE ENDOSCOPIC REMOVAL. THE OBJECTIVE OF THE STUDY WILL BE TO IDENTIFY OPTIMUM OPERATING PARAMETERS TO PERMIT SELECTIVE ABSORPTION OF LASER WAVELENGTH BY BILIARY STONES WITH MINIMAL ABSORPTION BY THE COMMON DUCT. SPECIFIC OBJECTIVES OF THE STUDY ARE (1) DETERMINE THE OPTIMUM LASER PARAMETERS - WAVELENGTH, PULSE ENERGY, PULSE- WIDTH, AND PULSE REPETITION FREQUENCY; (2) DEVELOP A SOLID STATE OR DYE LASER WITH THE APPROPRIATE OUTPUT CHARACTERISTICS; AND (3) ESTABLISH THE SAFETY AND EFFICACY OF THE TREATMENT TECHNIQUES IN ANIMAL STUDIES. THIS RESEARCH OFFERS THE POTENTIAL TO ESTABLISH OPERATING CRITERIA FOR A MINIMALLY INVASIVE SYSTEM TO REMOVE COMMON DUCT STONES. THE TECHNOLOGY COULD POTENTIALLY BE EXTENDED TO A PERCUTANEOUS TECHNIQUE TO TREAT STONES IN THE GALL- BLADDER. IF SUCCESSFUL, CLINICAL TRIALS WILL FOLLOW, AND CANDELA WILL PURSUE DESIGN, DEVELOPMENT, AND COMMERCIAL- IZATION OF A CLINICAL SYSTEM.