Transurethral needle ablation of the prostate (TUNA): pathological, radiological and clinical study of a new office procedure for treatment of benign prostatic hyperplasia using low-level radiofrequency energy.

Many attempts have been made to develop a method for treating BPH that is minimally invasive, efficacious and low-cost. TUNA is a new, fast anesthesia-free, outpatient device for selectively ablating prostatic tissue by delivering low-level radiofrequency power through a special 22 French urethral catheter positioned in the prostate via TURS and/or direct fiberoptic vision, and outfitted with adjustable needles placed in a selected prostatic area. A pilot study was performed in 70 patients to evaluate TUNA safety and feasibility via histopathological measurement and clinical outcome. Twenty-five patients were treated with TUNA prior to scheduled retropubic prostatectomy. The surgical prostatic specimens recovered from 1 day to 1 month after TUNA were step-sectioned and examined histologically. The TUNA procedure averaged 30 minutes; 4-15 Watts were applied for 3-5 minutes per lesion. The central lesion temperatures were above 100 degrees C. The urethral temperature averaged 41 degrees C and rectal temperature remained unchanged. Macroscopic and MRI examination of the specimens demonstrated localized lesions averaging 12 x 7 mm and 17 x 10 mm for 3 and 5 minutes of treatment, respectively. Microscopic examination of the specimens showed sharply delineated lesions of extensive coagulative necrosis measuring up to 35 x 15 mm. The clinical efficacy of the procedure was evaluated in 25 symptomatic BPH patients treated by TUNA. Tolerance using topical anesthetic and intravenous valium was excellent.(ABSTRACT TRUNCATED AT 250 WORDS)