Thermal effects of laser stapedectomy in an animal model: CO2 versus KTP

Although use of the laser for stapedectomy has become common in recent years, controversy remains regarding whether the CO2 or visible-spectrum lasers (argon and KTP) are best suited for this operation. The main concern has been the potential for thermal injury to the inner ear with the visible-spectrum lasers attributable to their absorption characteristics. To further investigate this issue, the author performed 20 laser stapedectomies on adult chinchillas. Following placement of a 0.127-mm-diameter copper/constantan thermocouple (sampling at 12 Hz) beneath the footplate on the medial wall of the vestibule via a distant fenestration site, thermal changes with a micromanipulator-based CO2 and fiberoptic KTP system were compared. This was the first live animal model comparison of these two lasers. There was no statistical difference in the mean temperature elevation between the two systems (P = 0.395).