Development of a carbon dioxide laser cystoscope

CO₂ laser lesions were created at varying power densities on the exteriorized canine bladders. A 50‐watt carbon dioxide continuous laser coupled to a Zeiss surgical microscope was used. A schematic power curve was developed indexing depth of bladder penetration by the laser against laser energy output. Once the optimal power settings for the carbon dioxide laser were established, vertical heat transmission, hemostasis, and healing were studied. A prototype carbon dioxide laser cystoscope was then constructed that allowed endoscopic delivery of the CO₂ laser beam into the intact canine bladder. The beam was focussed by a germanium lens and directed out the end of the endoscope, using a movable mirror. Eight dogs were then endoscopically studied in vivo.