Elevation of sensory thresholds in the prostatic urethra after microwave thermotherapy

Objectives To determine whether transurethral microwave thermotherapy (TUMT ) affects the sensory threshold in the posterior urethra and whether such a n effect influences urinary storage symptoms. Patients and methods The sensory threshold was measured before and at 3 and 12 weeks after TUMT in 13 men with minor obstructive symptoms caused by be nign prostatic hyperplasia. Sensations were evoked by electrical stimulatio n at different frequencies, using a bipolar ring-electrode mounted on a ure thral catheter. Changes in sensory thresholds were evaluated in the patient s both as a group and individually. The patients were interviewed about the ir symptoms at each measurement. Results After TUMT, 12 patients were satisfied and reported decreased irrit ative symptoms, primarily less frequent nocturnal micturition; two patients were cured of urgency incontinence. In 11 of the satisfied patients, and t he unsuccessful patient, decreased urge accompanied increased sensory thres holds. Thresholds elevated by greater than or equal to 30% were correlated with decreased irritative symptoms. Conclusions TUMT decreases sensitivity in the posterior urethra, which may alleviate storage symptoms.