CO2 laser stapedotomy.

This clinical study was preceded by two laboratory experiments. The first experiment compared temperature changes in the vestibule while vaporizing a 0.6-mm stapedotomy with Argon, KTP-532, and CO2 lasers. Data demonstrated that the CO2 laser possesses superior tissue characteristics for stapedotomy. In the second experiment safe energy parameters were established for various Sharplan CO2 laser models. Using these safe power settings, 153 consecutive CO2 laser stapedotomies were performed under local anesthesia. No patient experienced intraoperative dizziness during or immediately following the application of the CO2 laser to the stapes footplate. Long-term postoperative hearing results demonstrated that 87% of the patients maintained an air/bone gap to within 10 dB and 94% maintained an air/bone gap to within 15 dB (mean follow-up 32 months). No patient incurred a significant sensorineural hearing loss (greater than 10 dB) in the speech range. Four patients developed a perilymph fistula (three immediate and one delayed) and fluctuating sensorineural hearing loss, but all were successfully repaired without significant permanent nerve deafness. At 4,000 Hz, five patients lost 20 dB and two patients dropped 40 dB compared with preoperative levels. Postoperative complications included four perilymph fistulas, two prostheses displaced from the stapedotomy opening, one fixed prosthesis, and one fixed incus. Seven of eight of these complications were successfully revised. At the time of this writing, 6/153 patients have a persistent conductive hearing loss greater than 20 dB and have not been revised. Using appropriate energy parameters, the CO2 laser provides a safe, efficient microsurgical tool for performing stapedotomy simply and with minimum inner ear trauma.