ANALYSIS OF FIBER TIP DAMAGE RISK DURING PULSED HOLMIUM LASER APPLICATION UNDER WATER

Breaking of optical fibre tips during medical holmium laser applicatio ns involving endoscopic irradiation in a liquid environment, such as a rthroscopy, has been reported. This represents a risk of complications due to foreign body reactions induced by quartz fragments remaining a t the operation site. Fibre breakage has been analysed under controlle d conditions at clinically used laser energies of 20-1000 mJ, The gene ration of pressure transients at the collapse of laser-induced vapour bubbles is identified as the mechanism of fibre tip destruction, Fibre damage is observed only in a confining liquid envivronment, The highe st fibre damage occurrence is observed for laser fluences of 70-250 J cm(-2) at the bare fibre tip, at pulse durations of 200-350 mu s. The fibre damage occurrence and extent increase with the fibre diameter. A voiding the identified dangerous fluence range or use of fibres smalle r than 400 mu m diameter is recommended to perform endoscopic holmium laser application with minimal fibre damage risk.