EFFECTS OF CONTINUOUS-WAVE LASER SYSTEMS ON STAPES FOOTPLATE

Background and Objective: The aim of the present study was to clarify which of the presently available continuous-wave laser systems are bes t suited for application in stapes surgery. Study Design/Materials and Methods: Isolated human stapes and bovine compact-bone platelets were used to investigate the connections between the parameters of various laser systems and their effects on bone tissue. The purpose was to op timize the laser parameters required to achieve a perforation measurin g 500 mu m to 600 mu m in diameter. Three different laser systems were applied: the argon and CO2 laser in continuous wave (cw) mode and the CO2 laser in superpulse mode. Results: The suitability of the argon l aser for stapedotomy is doubtful in view of the lower absorption coeff icient of the stapes for the argon beam and the considerable influence which the degree of pigmentation of She irradiated medium exerts on i ts effect with the resultant poor reproducibility of the perforation d iameter. The beam of the CO2 laser is far better absorbed at the footp late than that of the argon laser. This results in higher effectivity, lower thermic side effects, and better reproducibility of the perfora tion. The two modes of the CO2 laser do not show any appreciable diffe rences. Conclusion: The experimental results presented indicate that t he CO2 laser in cw and superpulse mode is the most suitable of the sys tems now clinically applied in stapes surgery. (C) 1996 Wiley-Liss, In c.