Durability of laser fibers

Abstract

In 90 patients treated with laser prostatectomy using the Urolase (n = 50) or Ultraline (n = 40) laser fiber, the fiber-tip durability was investigated. In general the Urolase fiber tips were less damaged than the Ultraline fiber tips. At visual inspection, 62% of the Urolase fiber tips were graded as minimally damaged in comparison with 28% of the Ultraline group. The Urolase fiber tips are more susceptible than the Ultraline fiber tips to damage caused by tissue contact, whereas the latter seem more fragile. Transmission measurements were performed in a laboratory setting to estimate the loss of energy output at the fiber tip due to damage. These measurements showed a major loss in almost all fibers. None of the Ultraline fibers had less than 10% transmission loss, and 18% of the Urolaser fibers had a transmission value of more than 90%. Finally, there seemed to be a poor correlation between the visual aspects of the fibers used and the changes in transmission.

The Twister Fiber: A Comparative Study of Tissue Interaction Between This Novel Fiber and the Side-Firing Fiber Using the 980 nm Laser in Bovine Kidneys

“…Very few articles have addressed this issue. 15,16 It appears that the side-firing fiber is more resistant to degradation. In contrast to the side-firing fiber, which works in a near contact mode, the Twister fiber works in a contact mode.…”

Comparison of Fluence Rate Distributions Made by Side-Firing Fibers in an Optical Phantom

“…When the optical properties of the phantom used in this study ( a ϭ0.054 mm −1 , s ϭ0.997 mm −1 , g ϭ0. 48, and eff ϭ0.304 mm −1 or ␦ϭ3.3 mm) are compared to native canine prostate tissue 30 ( a ϭ0.04 mm −1 , s ϭ11 mm −1 , gϭ0.96, and eff ϭ0.24 mm −1 or ␦ϭ4.17 mm), and native human prostate tissue 30 ( a ϭ0.03 mm −1 , s ϭ8 mm −1 , g ϭ0.95, and eff ϭ0.197 mm −1 or ␦ϭ5.1 mm) there are obvious differences. The scattered light from a Nd:YAG beam launched into canine or human prostate tissue is almost totally scattered in the forward direction (cos Ϫ1 0.96ϭ16°) while the beam is scattered over a much wider area (cos Ϫ1 0.48ϭ61°) in a suspension of Intralipid and water.…”

“…It would also provide for performance evaluation at typical clinical exposure levels where the side-firing fiber's performance has been shown to deteroriate. 25,48 A preliminary investigation has been made into creating a liquid phantom whose optical properties matched those of native human prostate and has the ability to coagulate at the higher clinical power levels. The optical properties of a liquid phantom containing different concentrations of Intralipid and egg albumin were determined at the 1064 nm wavelength.…”

Lasers in the Treatment of Benign Prostatic Obstruction: Past, Present, and Future

“…This depends on a number of variables, such as reflection of laser light, changes in tissue charac teristics during lasing, tissue cooling via increased prostat ic blood flow, the color of the prostatic mucosa, and loss of power output due to fibertip decrease during the laser pro cedure. Several studies have been performed to investi gate the posttreatment decrease in the quality of the laser fibers [48,49]. Indeed, a difference in durability was found between the different fibers tested.…”