Temperature and luminosity outputs of endoscopes used in transcanal endoscopic ear surgery: an experimental study

To establish the relationship between endoscope temperatures and luminosity with a variety of light source types, endoscope ages, endoscope sizes, angles and operative distance in transcanal endoscopic ear surgery.

Transcanal endoscopic ear surgery was simulated in an operating theatre using 7 mm plastic suction tubing coated in insulating tape. An ATP ET-959 thermometer was used to record temperatures, and a Trotec BF06 lux meter was used to measure luminosity. Luminosity and temperature recordings were taken at 0 mm and 5 mm from the endoscope tip.

Thermal energy transfer from operating endoscopes is greatest when: the light intensity is high, there is a light-emitting diode light source and the endoscope is touching the surface. Additionally, larger-diameter endoscopes, angled endoscopes and new endoscopes generated greater heat.

It is recommended that operative light intensity is maintained at the lowest level possible, and that the surgeon avoids contact between patient tissues and the endoscope tip.