Elevation of sensory thresholds in the prostatic urethra after microwave thermotherapy.

Abstract

To determine whether transurethral microwave thermotherapy (TUMT) affects the sensory threshold in the posterior urethra and whether such an effect influences urinary storage symptoms. The sensory threshold was measured before and at 3 and 12 weeks after TUMT in 13 men with minor obstructive symptoms caused by benign prostatic hyperplasia. Sensations were evoked by electrical stimulation at different frequencies, using a bipolar ring-electrode mounted on a urethral catheter. Changes in sensory thresholds were evaluated in the patients both as a group and individually. The patients were interviewed about their symptoms at each measurement. After TUMT, 12 patients were satisfied and reported decreased irritative symptoms, primarily less frequent nocturnal micturition; two patients were cured of urgency incontinence. In 11 of the satisfied patients, and the unsuccessful patient, decreased urge accompanied increased sensory thresholds. Thresholds elevated by >/= 30% were correlated with decreased irritative symptoms. TUMT decreases sensitivity in the posterior urethra, which may alleviate storage symptoms.