Effects of continuous-wave laser systems on stapes footplate.
OBJECTIVE
The aim of the present study was to clarify which of the presently available continuous-wave laser systems are best suited for application in stapes surgery.


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 optimize the laser parameters required to achieve a perforation measuring 500 microns to 600 microns 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 laser for stapedotomy is doubtful in view of the lower absorption coefficient of the stapes for the argon beam and the considerable influence which the degree of pigmentation of the irradiated medium exerts on its effect with the resultant poor reproducibility of the perforation diameter. The beam of the CO2 laser is far better absorbed at the footplate than that of the argon laser. This results in higher effectivity, lower thermic side effects, and better reproducibility of the perforation. The two modes of the CO2 laser do not show any appreciable differences.


CONCLUSIONS
The experimental results presented indicate that the CO2 laser in cw and superpulse mode is the most suitable of the systems now clinically applied in stapes surgery.
Jovanovic
S
S
ENT Department, Benjamin Franklin Medical Center, Free University of Berlin, Germany.
Schönfeld
U
U
Prapavat
V
V
Berghaus
A
A
Fischer
R
R
Scherer
H
H
Müller
G J
GJ
D000818:Animals; D002417:Cattle; D006801:Humans; D066298:In Vitro Techniques; D053685:Laser Therapy / Q000379:methods*; D007834:Lasers; D013199:Stapes / Q000528:radiation effects*; D013201:Stapes Surgery / Q000379:methods*