Effects of pulsed laser systems on stapes footplate

Ultrashort pulse laser ossicular ablation and stapedotomy in cadaveric bone*†

“…1 and 2) reveal a circular channel through the long process of the incus measuring 400 microns in diameter. The higher magni®cation image in Figure 2 demonstrate little evidence of explosive damage from expanding gases due to vaporization of the tissue matrix commonly seen in ablation craters created using Holmium [8,18,21] or erbium [8,18] lasers. For comparison, see images published by Neev [8], Jovanovic [8], and Wong [21].…”

“…These ®ndings suggest thermal vaporization of the water or organic bone contents with subsequent violent ejection of both organic and inorganic components. Ablation experiments on the stapes footplate by Jovanovic also demonstrate evidence of carbonization and thermal injury [8,22,23]. Peavy et al [24] demonstrated similar SEM ®ndings from free electron laser (FEL) ablation of cortical bone.…”

A comparison of the hearing results of KTP and Erbium YAG laser stapedotomy

“…It proves that the Er: YAG laser is just as useful as any other laser used in the stapes surgery. Whereas the KTP and argon lasers bear the risk of inner ear damage due to their light transmission through fluids, for example, perilymph, other lasers*such as the pulsed carbon dioxide laser or the excimer*were assumed to be unsuitable for stapedotomy because of their heat generation at parameters effective for footplate perforation [9]. The Er: YAG laser has the advantage of its high absorption in bone, the absence of heat generation in surrounding structures, no penetration through the perilymph and very limited border damage zone [4].…”

Chapter 9 Lasers in Otosclerosis

“…This was indicative of a significant shock wave phenomenon. Jovanovic et al (1995) found that the Er:YSGG laser produced a 3.6°celsius elevation in temperature from the footplate, and the CO 2 laser produced an 8.8°celsius temperature increase. The researchers were concerned that the shock waves could be introduced into the perilymph with the potential to damage the inner ear structures.…”