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Penetration of CO 2 laser into the otic capsule using a hand‐held, flexible‐fiber delivery system
Author(s) -
Majdani Omid,
Wittkopf Justin,
Dietrich Mary S.,
Labadie Robert F.
Publication year - 2009
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.20800
Subject(s) - penetration (warfare) , laser , cadaveric spasm , clearance , capsule , ablation , biomedical engineering , temporal bone , materials science , medicine , surgery , optics , mathematics , geology , physics , operations research , urology , paleontology
Background and Objective Recently, a new, flexible‐fiber, CO 2 laser delivery system has been FDA‐cleared for clinical use. However, for otologic surgery, no data have been reported correlating power settings to depth of penetration into the otic capsule—the bone that covers the inner ear. This was the goal of our study. Study Design/Materials and Methods Eight cadaveric temporal bones were procured as per our institution's protocols. For each specimen, nine different laser holes were burned into the otic capsule using the flexible‐fiber CO 2 laser delivery system. Power settings were varied from 10 to 20 W in 2 W increments, and duration of exposure was 100, 200, 300, 400, or 600 milliseconds. Each setting (power and duration) was tested on two specimens. Following laser exposure, each specimen was scanned in a microCT scanner, and the depth of penetration measured from these images. Results Of the 72 laser shots, 8 were excluded due to double hits (4), oblique hits (3), or complete penetration (1). After excluding these 8, bone penetration was found to vary from 160 to 670 µm based on power and time settings. Spearman analysis on ranked data showed that time had a greater impact on depth than power. The correlation coefficients for time and power were 0.84 ( P = 0.013) and 0.40 ( P <0.001), respectively. Conclusion The flexible‐fiber CO 2 laser is effective for otic capsule ablation in this model. High power setting and long pulse duration can lead to complete penetration of the otic capsule potentially causing damage of underlying structures such as the facial nerve, horizontal semicircular canal, and cochlea. Lasers Surg. Med. 41:509–513, 2009. © 2009 Wiley‐Liss, Inc.