Experimental investigations on the suitability of the carbon dioxide laser for stapedotomy

Surgery of the footplate may cause a number of possible complications such as cochlear hearing defects or even complete loss of hearing. This has made it necessary to look for improved techniques. When a laser is used for stapedotomy, the energy transmitted to the cochlea must be reduced to the lowest possible level. We thus investigated the carbon dioxide laser to determine whether it would prove to be more advantageous than the argon laser. Animal experiments showed that CO2 laser irradiation is well tolerated. Tests performed on isolated petrous bone resulted in the development of a new surgical instrument suitable for stapedotomy using the CO2 laser. Temperature and pressure measurements were carried out on a simplified model of the human cochlea. Our findings indicated that, with both types of laser, the irradiation required to perforate the otosclerotically thickened footplate adversely affects temperature and pressure development in the cochlea.