In vivo effects of transurethral balloon laser prostatectomy on the canine prostate.

Twenty-three dogs received prostatectomy by transurethral balloon laserthermia, and the in vivo effects and morbidity were evaluated. The prostate was heated transurethrally, and tissue temperature at a depth of 5 mm. from the urethral mucosa was maintained at 60C for 20 minutes. Immediately after the treatment, coagulative necrosis was observed around the urethra to an average depth of 5 mm., and the tissue started to slough off within 1 week. Cavity formation and reepithelialization were complete after 4 weeks. Histologically, no tissue damage was found in the bladder neck or the urethral sphincter. The cavity formation threshold was 46.1C for 20 minutes. There was no incontinence or macroscopic hematuria in any case. No abnormality was found in hematological or biological examinations after treatment. From these data, the clinical use of transurethral balloon laserthermia for prostatectomy is considered both safe and effective.