Get access

Heat development at nasal endoscopes' tips: Danger of tissue damage? A laboratory study

Authors

  • Peter Valentin Tomazic MD,

    Corresponding author
    1. Department of General Otorhinolaryngology, Head and Neck Surgery, Medical University Graz, Graz, Austria
    • ENT-University Hospital Graz, Medical University Graz, Auenbruggerplatz 26/28, 8036 Graz, Austria
    Search for more papers by this author
    • Peter Valentin Tomazic MD, and Georg Philipp Hammer, MD, contributed equally to this article.

  • Georg Philipp Hammer MD,

    1. Department of General Otorhinolaryngology, Head and Neck Surgery, Medical University Graz, Graz, Austria
    Search for more papers by this author
    • Peter Valentin Tomazic MD, and Georg Philipp Hammer, MD, contributed equally to this article.

  • Claus Gerstenberger DI,

    1. Department of General Otorhinolaryngology, Head and Neck Surgery, Medical University Graz, Graz, Austria
    Search for more papers by this author
  • Wolfgang Koele MD,

    1. Department of General Otorhinolaryngology, Head and Neck Surgery, Medical University Graz, Graz, Austria
    Search for more papers by this author
  • Heinz Stammberger MD

    1. Department of General Otorhinolaryngology, Head and Neck Surgery, Medical University Graz, Graz, Austria
    Search for more papers by this author

  • The authors have no funding, financial relationships, or conflicts of interest to disclose.

Abstract

Objectives/Hypothesis:

The aim of this study was to measure the temperature generated by light sources in conjunction with angulated endoscopes and to analyze whether the heat generated at the endoscopes' tips harbors potential damage to mucosa or highly sensitive structures like the optic nerve or brain when in direct contact, considering a beginning necrosis of human protein starting at 40°C.

Study Design:

Laboratory setting, prospective.

Methods:

Brand new 4-mm, 0° and 30° rigid nasal endoscopes were measured each with halogen, xenon, and light-emitting diode (LED) light sources, respectively, at different power levels for tip contact temperature.

Results:

The highest temperatures were reached with a xenon light source at a maximum of 44.3°C, 65.8°C, and 91.4°C at 33%, 66%, and 100% power levels, respectively, for 4-mm, 0° endoscopes. For 30° endoscopes, temperatures of 47.0°C, 75.1°C, and 95.5°C were measured at 33%, 66%, and 100% power levels (P < .001; 0° vs. 30°), respectively. At 5-mm distance from the tip, temperatures were below body temperature for all light sources (<36°C) at all power settings. Within 2 minutes after switching off light sources, temperatures dropped to room temperature (22°C).

Conclusions:

Xenon light sources have the greatest illumination potential; however, at only 33% power level, potentially harmful temperatures can be reached at the tips of the endoscopes. Power LED and halogen have the highest safety; however, only LED has very good illumination. In narrow corridors, direct contact to tissues or vital structures should be avoided, or endoscopes should be cooled during surgical procedures.

Ancillary