Effect of KTP laser cochleostomy on morphology in the guinea pig inner ear.
BACKGROUND
The main advantage of using the KTP (potassium-titanyl-phosphate) laser for stapedotomy instead of the conventional micropick instrument is the smaller risk for mechanical damage. However, the KTP laser could theoretically inflict damage to inner ear structures. We hypothesize that KTP laser light [wavelength (λ) = 532 nm] is hardly absorbed in perilymph but well absorbed in solid structures. The aim of this pilot study was to assess if damage occurred after KTP laser cochleostomy in an animal model and, if so, to what extent and at which settings.


METHODS
In six guinea pigs, a KTP laser cochleostomy at the basal turn was created. Laser settings of 1, 3 and 5 W and 100 ms pulse time (n = 2 each) were used. Histological preparations were studied for damage to neuroendothelial cells and intrascalar blood.


RESULTS
No damage to inner ear neuroendothelial cells was observed, even at the highest power. Blood clots in the scala tympani from vessels in the cochlear wall were seen. The effects were minimal in the lowest, currently clinically used settings.


CONCLUSIONS
KTP laser cochleostomy gives no damage to inner ear neuroendothelial cells but may cause intrascalar hemorrhages.
Department of Otorhinolaryngology and Head and Neck Surgery, University Medical Center Utrecht, Utrecht, The Netherlands.
Digna M A
DM
Kamalski
Jeroen P M
JP
Peters
Tjeerd
T
de Boorder
Franco
F
Trabalzini
Sjaak F L
SF
Klis
Wilko
W
Grolman
D000818:Animals; D003051:Cochlea / Q000601:surgery*; D005260:Female; D005276:Fenestration, Labyrinth / Q000379:methods*; D006168:Guinea Pigs; D006470:Hemorrhage / Q000209:etiology; D053844:Lasers, Solid-State / Q000009:adverse effects / Q000627:therapeutic use*; D023421:Models, Animal; D010865:Pilot Projects; D012533:Scala Tympani / Q000473:pathology; D054738:Scala Vestibuli / Q000473:pathology