CO2 laser for otosclerosis: safe energy parameters.

Safe energy parameters for each Sharplan CO2 laser model (734, 1040, 1100A) were established in the laboratory. Ultrasensitive pyroelectric detectors analyzed the precise energy package delivered to the operative field with each of these power setting. Subsequently, 0.6-mm stapedotomy and stapedectomy revisions were performed under simulated operating room conditions while measuring temperature changes in the vestibule with a thermocouple. Table I illustrates safe energy settings for each of the Sharplan CO2 models tested. These power settings produced no more than 0.3 degrees C temperature rise in the vestibule during stapedotomy, and no more than 0.5 degrees C during stapedectomy revision. Following these guidelines, the CO2 laser was then employed to perform stapedotomy and stapedectomy revisions in otosclerosis patients. In over 200 consecutive operations performed under local anesthesia with the CO2 laser, no patient became dizzy intraoperatively while the CO2 laser was applied to the stapes footplate or the oval window neomembrane, confirming the lack of significant caloric effect to the inner ear at these energy settings. More importantly, no patient has yet experienced significant sensorineural hearing loss in the speech range.