Photoselective Vaporization of the Prostate: Initial Experience with a New 80 W KTP Laser for the Treatment of Benign Prostatic Hyperplasia

Purpose: To study the safety and efficacy of a new high-power potassium-titanyl-phosphate laser (KTP/532; Niagara PV™ laser system; Laserscope, San Jose, CA) for transurethral photoselective vaporization of benign obstructive prostate tissue.

Patients and Methods: The KTP/532 laser energy at 80 W was delivered by a 6F side-firing fiber through a 23F continuous-flow cystoscope. Photoselective vaporization of the prostate (PVP) using sterile water irrigation was performed under spinal anesthesia on an outpatient basis in 10 patients with a preoperative mean prostate volume of 41.37 ± 18.5 cc (range 24-76.3 cc). The mean lasing time was 19.8 ± 4.9 minutes.

Results: Two patients experienced 1 to 7 days of mild dysuria, and one who was taking warfarin had mild transient hematuria, but none had urinary retention or other complications. The mean catheterization time was 17.2 ± 9.6 hours (range 0-28 hours). At 1 year, the outcomes, which had showed significant improvement sustained throughout the follow-up, were as follows: mean American Urological Association Symptom Score decreased from 23.2 ± 4.7 to 2.6 ± 0.5 (88.8%), the mean quality of life score improved from 4.3 ± 0.7 to 0.4 ± 0.5 (90.7%), the mean peak urinary flow rate increased from 10.3 ± 1.4 mL/sec to 30.7 ± 5.8 mL/sec (198.1%), and the mean postvoiding residual volume decreased from 137.6 ± 112.2 mL to 3.0 ± 4.8 mL (97.8%). The mean prostate volume decreased by 27%.

Conclusions: This pilot study indicates that PVP with the new 80 W KTP/532 laser is a simple, safe, and efficacious outpatient procedure for the treatment of obstructive BPH.