Safety and efficacy of transurethral needle ablation of the prostate for symptomatic outlet obstruction

Abstract

Objectives: To examine, in an observational study, the safety and efficacy of transurethral needle ablation (TUNA) of the prostate as a treatment for symptomatic benign prostatic enlargement.

Patients and methods: This prospective study included 71 symptomatic men with unequivocal obstruction on pressure-flow urodynamics. The variables measured at baseline and up to 12 months after treatment included the American Urological Association (AUA)-7 symptom index and an added quality-of-life question, the AUA BPH-Impact Index, a sexual function score, transrectal ultrasonography of the prostate, a frequency-volume chart, free-flow uroflowmetry, post-void residual urine volume (PVR) and pressure-flow urodynamics. Transurethral resection of the prostate (TURP) was offered if the symptoms failed to resolve at any time during the follow-up period. TUNA was performed under local anaesthetic and sedation in 63 (89%) men and as a day-case procedure in 10 (14%). Five patients were on warfarin which was not discontinued.

Results: There were no serious treatment-related adverse events. Eight of the initial nine patients who were not routinely catheterized after treatment with TUNA developed acute urinary retention. Although some haematuria occurred in all patients, only one (1.4%) developed catheter blockage by clot. There were no problems with bleeding in those patients on warfarin at the time of treatment. The mean (95% confidence interval, CI) AUA-7 index fell from 23 (1.7) to 10.6 (1.8) (P < 0.001, Mann-Whitney U-test) at 12 months, 29 men (41%) had an AUA-7 index of < or = 7. The maximum (95% CI) urinary flow rate increased from 9.0 (0.8) to 11.3 (1.1) mL/s (P < 0.001) and this was accompanied by a small but significant reduction in PVR of 70 (14) mL to 35 (8) mL (P < 0.001 Mann-Whitney U-test). There was a significant reduction in both maximal voiding pressure and detrusor pressure at peak flow at 3 months (Mann-Whitney U-test, both P < 0.001) and at 12 months (P < 0.001, Wilcoxon matched-pairs signed-ranks test). However, 78% of the 45 men undergoing repeat pressure-flow studies at 12 months were unequivocally obstructed according to the Abrams-Griffiths nomogram. The mean (95% CI) prostatic volume fell from 49.0 (4.8) mL at baseline to 40.8 (4.9) mL at 3 months, but this change was not statistically significant (P = 0.011, Mann-Whitney U-test). Two men reported erectile dysfunction, one experienced ejaculatory problems and seven reported an improvement in erectile function after TUNA. During the study, 22 men (31%) underwent TURP.

Conclusions: TUNA is a safe treatment which can be performed as an out-patient procedure under local anaesthesia and sedation in the vast majority of patients. There was no evidence of serious adverse events and no significant adverse effect on sexual function. The symptomatic improvement was sustained at 12 months in most (54%) patients, with modest improvements in peak flow rate, PVR and voiding pressures, indicating that TUNA may result in prolonged symptomatic improvement in a proportion of patients suffering from bladder outlet obstruction. A randomized controlled study against established therapies is now essential to clearly delineate its place in the management of such patients.