[New microwave transurethral hyperthermia for benign prostatic hyperplasia--clinical evaluation].

Several types of hyperthermic apparatuses are employed to treat benign prostatic hyperplasia (BPH). As the prostate surrounds the urethra, we believed that transurethral heating allowed for more efficient and uniform heating. A new effective apparatus for this objective was developed. The size of our hyperthermic apparatus was about 52 x 45 x 20 centimeters and the originating frequency was 2,450 +/- 30 MHz. We used T-type thermocouples as temperature sensors. The transurethral applicator had a cooling system. Thirty patients complaining of obstructive symptoms due to BPH were treated. Hyperthermia was performed 3-6 times for each patients (two times per week). Each procedure was performed for 60 minutes. The temperature was controlled at 39 degrees C on the urethral surface (43 degrees C at prostate). The overall efficacy of this treatment was effective in 23 of the 30 patients (76.7%). In addition, there were no severe complications. As the size of this apparatus was miniaturized, it could be used at the bed side.