POTASSIUM-TITANYL-PHOSPHATE LASER VAPORIZATION OF THE PROSTATE - A COMPARATIVE FUNCTIONAL AND PATHOLOGICAL-STUDY IN CANINES

Objectives. We compared the functional and pathologic results of potas sium-titanyl-phosphate (KTP) laser vaporization prostatectomy with tho se of neodymium:yttrium-aluminum-garnet (Nd:YAG) laser vaporization an d coagulation prostatectomy in dogs. Methods. The prostates of 41 dogs were treated with KTP laser vaporization (n = 21), Nd:YAC laser vapor ization (n = 10), or Nd:YAG laser coagulation (n = 10). Dogs were sacr ificed 2 days or 8 weeks after treatment. Prostates were weighed, meas ured, serially sectioned, and whole-mounted for histologic analysis. R esults. All techniques were hemostatic, and no irrigant absorption was detected. KTP laser vaporization produced a prostatic defect with a m ean diameter of 3.0 and 2.4 cm at 2 days and 8 weeks postoperatively, respectively. Smaller defects (P<0.0005 at 2 days and P<0.02 at 8 week s) were produced by Nd:YAC laser vaporization (2.0 and 1.4 cm, respect ively) and coagulation (0.5 and 0.9 cm, respectively). No dog treated with KTP laser vaporization was incontinent or developed urinary reten tion, including 5 dogs whose urethral catheters were removed within 24 hours of surgery. Conclusions. KTP laser vaporization prostatectomy n ot only provides hemostasis similar to that obtained with Nd:YAG laser coagulation, but also removes tissue at the time of operation, allowi ng dogs to void without straining within 24 hours of treatment. In add ition, the procedure is technically simple, and the operator has excel lent control over exactly which tissue is removed and which is left in tact. These findings suggest that KTP laser vaporization may be useful in the treatment of human benign prostatic hyperplasia.