Transurethral microwave hyperthermia for benign prostatic hyperplasia: the Leuven clinical experience

摘要

Abstract: Transurethral microwave hyperthermia is a new conservative treatment modality for benign prostatic hyperplasia. From April 1989 until July 1990, 104 patients were treated using this method, with a mean post-treatment follow-up of 6 months. Seventy-four patients were admitted with subjective and objective low outflow obstructive parameters. Thirty were admitted because of acute urinary retention. Five to 10 hyperthermia sessions were administered on an outpatient basis during which 915 MHz microwaves were delivered to the prostate. In the group of patients with a bilobular hyperplasia, an improvement of the total FDA symptom scale with at least 5 points was noted in 60% after 6 months. Major improvement was noted in obstructive symptoms. Those patients with a trilobular hypertrophy showed an improvement in 40%, for a median bar obstruction 28.6% and for medium lobe hyperplasia 41.1%. The most important improvement in the mean average flow and mean peak flow was also noted in the patients with bilobular or trilobular hypertrophy. In both groups a slight decrease of postvoiding residual urine was noted. In those patients with acute urinary retention, 17 out of 23 with a bilobular hypertrophy regained spontaneous micturition. All of those with a median lobe or median bar obstruction required operation. During treatment the patients experienced bladder spasms, perineal pain, and minor urethral bleeding. Approximately 10% of patients had symtomatic urinary infection, which responded well to an appropriate therapy. Post hyperthermia histologic examination of the prostate revealed myonecrosis and thrombosis of the superficial blood vessels with fibrotic reorganization which seemed to be completed three weeks after the end of treatment. This suggests that transurethral microwave hyperthermia induces shrinking of the periurethral prostatic tissue and lowers the static outflow obstruction component.!