KTP green laser vaporization of biologic tissue under water and its clinical application.

OBJECTIVES: This study aimed to assess the effect of various power settings of the potassium-titanyl-phosphate (KTP) green laser on the vaporization of biological tissue under water and its potential and feasibility to treat patients with benign prostatic hyperplasia (BPH) and other urological disorders.

BACKGROUND DATA: BPH, ureteral strictures, and bladder tumors are common urological diseases in elderly men. KTP green laser vaporization is a safe and effective procedure used to treat urological diseases.

METHODS: Porcine muscles were vaporized at different power levels (7.5-57 W) under water by the KTP green laser system. Fresh canine prostate tissues were also vaporized with a 43-W green laser. Laser vaporization of human urological tissue was performed clinically.

RESULTS: The porcine muscles were vaporized under water for 10 sec. Increasing laser power appeared to increase the depth and diameter of vaporization while maintaining or decreasing the depth of necrosis. With the 60-W KTP green laser system, laser prostatectomy was performed on 15 patients with BPH. This green laser system was also used to treat 12 strictures and 9 superficial bladder tumors. All patients received spinal anesthesia, and isotonic saline at room temperature was used as irrigation solution. Postoperative insertion of an indwelling catheter was mandatory.

CONCLUSIONS: With increasing laser power settings, the vaporization depth and width increased significantly, but the depth of necrosis declined slightly. Green laser vaporization is a treatment method that can be adopted to treat patients with BPH, urethral stricture, and other urological diseases safely and effectively.