Safety of heat generated by endoscope light sources in simulated transcanal endoscopic ear surgery

• Published in: Auris, nasus, larynx Vol. 43; no. 5; pp. 501 - 506
• Main Authors: Ito, Tsukasa, Kubota, Toshinori, Takagi, Akira, Watanabe, Tomoo, Futai, Kazunori, Furukawa, Takatoshi, Kakehata, Seiji
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ireland Ltd 01.10.2016
• Subjects: Ear surgery; Ear, Middle - surgery; Endoscope; Endoscopes; Hot Temperature; Humans; LED light source; Lighting; Middle ear cavity; Models, Anatomic; Otolaryngology; Otologic Surgical Procedures - instrumentation; Temperature; Xenon light source; Middle ear cavity; Temperature; Ear surgery; Xenon light source; LED light source; Endoscope
• ISSN: 0385-8146; 1879-1476
• DOI: 10.1016/j.anl.2015.12.014

Abstract Objective To determine whether heat generated by endoscope light sources during ear surgery is safe. Methods Transcanal endoscopic ear surgery (TEES) was simulated using 2.7-mm or 4-mm endoscopes coupled to xenon or LED light sources and a 3D model of human temporal bone. The endoscope tip was fixed at the center of tympanic annulus. Light sources were tested at clinical (30% for xenon and 40% for LED) and 100% settings. Temperatures were measured using thermocouples attached to the endoscope tip and three points within the middle ear cavity: promontory, horizontal portion of the facial nerve and lateral semicircular canal. Results Maximum temperatures measured within the middle ear cavity were below 31 °C at clinical settings, while the temperatures rose to 44.1 °C using a 4-mm endoscope with a xenon light source set at 100%. Temperatures measured at the tip were all safe at clinical settings, but rose dramatically to 110.1 °C for the 4-mm endoscope with xenon at 100%. Conclusion Endoscopes can be safely used within the middle ear at clinical settings. However, operators should not exceed clinical settings, particularly with 4-mm endoscopes with a xenon light source, to ensure temperatures generated within the middle ear cavity are safe.