Effectiveness of the CO2 laser in experimental tympanic neurectomy.

As one of a series of investigations to evaluate the efficacy and safety of CO2 lasers in otologic microsurgery, squirrel monkeys were subjected to tympanic neurectomies by means of vaporizing Jacobson's nerve in the promontory region. Air and bone conduction hearing acuity was measured by computer-averaged pure tone evoked responses and behavioral audiometry before and after laser surgery. A moderate (avoidable) conductive loss was found as a consequence of the surgical approach selected, but no significant sensorineural loss was apparent. Thus, there would appear to be no adverse cochlear side effects as a result of using this instrument in the middle ear. The laser neurectomy procedure, however, was no more effective for the clinical purposes for which it was proposed than those techniques reported by several other investigators.