Is loss of power output due to laser fiber degradation still an issue during prostate vaporization using the 180 W GreenLight XPS laser?

• Published in: World journal of urology Vol. 37; no. 1; pp. 181 - 187
• Main Authors: Hermanns, Thomas, Grossmann, Nico C., Wettstein, Marian S., Keller, Etienne X., Fankhauser, Christian D., Gross, Oliver, Kranzbühler, Benedikt, Lüscher, Martin, Meier, Alexander H., Sulser, Tullio, Poyet, Cédric
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.01.2019; Springer Nature B.V
• Subjects: Aged; Cancer surgery; Electric Power Supplies; Energy; Equipment Failure; Fibers; Humans; Laser Therapy - instrumentation; Lasers; Male; Medicine; Medicine & Public Health; Nephrology; Oncology; Original Article; Prospective Studies; Prostate; Prostate cancer; Prostatic Hyperplasia - complications; Prostatic Hyperplasia - surgery; Treatment Outcome; Urinary Bladder Neck Obstruction - etiology; Urinary Bladder Neck Obstruction - surgery; Urological surgery; Urology; Prostatic hyperplasia; Disposable equipment; Laser fiber laser prostatectomy; Transurethral resection of prostate; Lasers; Equipment failure analysis
• ISSN: 0724-4983; 1433-8726
• DOI: 10.1007/s00345-018-2377-5

Purpose To investigate whether heat-induced fiber degradation and loss of power output, which occurred during GreenLight laser vaporization (LV) of the prostate using the first- and second-generation 80 and 120 W laser, are still an issue during LV using the upgraded third generation 180 W GreenLight XPS™ laser. Methods Laser beam power output of 53 laser fibers was measured at baseline and after every 25 kJ of delivered energy during routine 180 W GreenLight XPS™ LV in 47 patients with prostatic bladder outflow obstruction. After the procedures, the fiber tips were microscopically examined. Results The median applied energy per patient was 178 kJ [interquartile range (IQR): 106–247]. Loss of power output during the procedure was detectable in all fibers. After the application of 25, 150, and 250 kJ, the median power output decreased to 77% (IQR 59–87), 57% (IQR 32–71), and 51% (IQR 37–64) of the baseline value. Nine fibers (17%) remained on a relatively high power output level (> 80% of the initial output), while 13 fibers (25%) showed an end-of-procedure power output of less than 20%. Microscopy of the fiber tip revealed mild-to-moderate overall degradation and increasing degradation with higher energy delivered. Conclusion Despite changes in fiber design, heat-induced fiber damage and loss of power output remain an issue during 180 W GreenLight XPS™ LV. Whether modifications of the surgical technique can prevent impairment of fiber performance needs to be further evaluated.