Transurethral microwave thermotherapy of benign prostatic hypertrophy

Abstract

Transurethral microwave thermotherapy using Prostatron was performed in 31 patients with benign prostatic hypertrophy, and the clinical effectiveness was evaluated by analyzing the subjective and objective responses following the treatment. The 22F balloon catheter to be placed in the prostatic urethra incorporates the microwave antenna, a cooling system and a fiberoptic thermosensor which allow an effective delivery of microwave energy to the center of the prostate, while preserving the mucosa and periurethral tissue. The maximum urethral temperature during the treatment ranged from 43.3 to 45.5 degrees C (44.7 +/- 0.96 degrees C: mean +/- S.D.) and the average power output was 27.4 Watt. The treatment was performed in a single session of an hour on the outpatient basis. In one patient who could not be relieved of the indwelling catheter underwent a transurethral resection, and the histological effect of thermotherapy on the resected specimen was examined. In the prostatic tissue, heat-induced necrotic change of the interstitial tissue as well as degenerative change of the acinar epithelium were remarkable, whereas the urethral mucosa was well preserved. In the remaining 30 patients, the clinical effects were evaluated 8 weeks after the treatment by a score scale for subjective symptoms, residual urine and maximum urinary flow rate, which was compared with the pretreatment score. Improvement of both subjective symptoms and objective findings was observed in 13 subjects (43.3%), that of subjective symptoms only in 14 cases, and that of objective findings only in 2 cases, resulting in a notable improvement in total 29 cases (97.7%).(ABSTRACT TRUNCATED AT 250 WORDS)