Intra-operative power measurement of laser fibers during photoselective vaporization of the prostate using the 80W-KTP-Greenlight laser

Photoselective vaporization of the Prostate (PVP) using the 80W-Greenlight-PV(R) Laser System (Laserscope(R), San Jose, USA) has been established as a treatment option for patients suffering from obstructive symptoms caused by benign prostatic hyperplasia. However, longer operation time compared to standard trans-urethral resection of the prostate (TURP) and the high costs of the laser fibers are specific problems of this technique. In addition, many clinicians performing PVP complain about a reduced effectiveness of vaporization during treatment. Therefore, power measurement was performed during PVP using the 80W-Greenlight-PV(R) Laser System. Power output was measured at the beginning and also regularly throughout the operation. A total of 40 fibers were investigated in 35 patients. Damage to the tip of the fibers was regularly visible and increased as more energy was supplied. Additionally, in 90% of all fibers a decrease of power output was detectable during the operation. This became pronounced after the application of 200kJ, resulting in an end of lifespan (i.e. 275kJ) median power output of only 20% of the starting value. Corresponding to the clinical observations the impressive damage to the emission window was associated with a substantial decrease of power output during PVP. These observations might explain the impaired vaporization during PVP and a longer operation time compared to conventional TURP. Hence, improvements in the quality of the laser fibers are necessary to advance the efficiency of this promising technology.© (2008) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.