Thulium:YAG laser for stapes surgery: preliminary observations

摘要

This study investigates the value of the Thulium:YAG laser ($lambda $EQ 2.01 $mu@m) for otological applications. Fresh human stapes were used. The laser was used at fluences of 64 - 328 J/cm$+2$/ per pulse in single pulse application with a pulse width of 700 $mu@sec. The energy was delivered through a 300 $mu@m fiber. The stapes were irradiated on an acrylic model vestibule with a thermocouple 2 mm below the surface. Perforations were performed at five fluence settings; the peak and sustained temperature rises were recorded. The `open vestibule' was then exposed to direct laser energy above 2 mm lateral to the thermocouple to mimic an open footplate. The stapes were submitted for pathological examination. The laser output had an average pulse to pulse variability of 8%. On average it took 16 pulses to perforate the footplate at the lowest energy and 2 pulses at the highest. There was little charring of the bone. The results are comparable to other mid-infrared lasers.