Hypothesis: The mechanical and acoustic effects that occur during laser-assisted stapedotomy differ among KTP, CO2, and thulium lasers.
Background: Making a fenestration in stapedotomy with a laser minimizes the risk of a floating footplate caused by mechanical forces. Theoretically, the lasers used in stapedotomy could inflict mechanical trauma because of absorption in the perilymph, causing vaporization bubbles. These bubbles can generate a shock wave, when imploding.
Methods: In an inner ear model, we made a fenestration in a fresh human stapes with KTP, CO2, and thulium laser. During the fenestration, we performed high-speed imaging from different angles to capture mechanical effects. The sounds produced by the fenestration were recorded simultaneously with a hydrophone; these recordings were compared with acoustics produced by a conventional microburr fenestration.
Results: KTP laser fenestration showed little mechanical effects, with minimal sound production. With CO2 laser, miniscule bubbles arose in the vestibule; imploding of these bubbles corresponded to the acoustics. Thulium laser fenestration showed large bubbles in the vestibule, with a larger sound production than the other two lasers. Each type of laser generated significantly less noise than the microburr. The microburr maximally reached 95 ± 7 dB(A), compared with 49 ± 8 dB(A) for KTP, 68 ± 4 dB(A) for CO2, and 83 ± 6 dB(A) for thulium.
Conclusion: Mechanical and acoustic effects differ among lasers used for stapedotomy. Based on their relatively small effects, KTP and CO2 lasers are preferable to thulium laser.
*Department of Otorhinolaryngology and Head & Neck Surgery, †Brain Center Rudolf Magnus, University Medical Center Utrecht; ‡Department of Physics and Medical Technology, VU University Medical Center Amsterdam; §Department of Medical Technology and Clinical Physics, University Medical Center Utrecht, The Netherlands; and ∥Jean Causse Ear Clinic, Transverse de Béziers, Colombiers, France
Address correspondence and reprint requests to Digna M. A. Kamalski, M.D., Department of Otorhinolaryngology, University Medical Center Utrecht: Heidelberglaan 100, G05.1293584 CX Utrecht, The Netherlands; E-mail: firstname.lastname@example.org
Some of the laser equipment used for this study was provided by Omniguide, Cambridge, MA, USA.
The authors disclose no conflicts of interest.
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