Transurethral intraprostatic injection of botulinum neurotoxin type A for the treatment of chronic prostatitis/chronic pelvic pain syndrome: results of a prospective pilot double-blind and randomized placebo-controlled study

Objective: To evaluate the effect of botulinum neurotoxin type-A (BoNT-A) on chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) refractory to medical therapy.

Materials and methods: Between November 2011 and January 2013, 60 men aged ≥18 years with CP/CPPS, and with National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) scores ≥10 and pain subscale scores ≥8, who were refractory to 4-6 weeks' medical therapy, underwent transurethral intraprostatic injection of BoNT-A or normal saline in a prospective pilot double-blind randomized study. The patients' NIH-CPSI total and subscale scores, American Urological Association (AUA)-symptom score (SS), visual analogue scale (VAS) and quality of life (QoL) scores and frequencies of diurnal and nocturnal urination were evaluated and compared at baseline and at 1, 3 and 6 months after injection and also were compared between the two groups.

Results: A total of 60 consecutive patients were randomized to a BoNT-A (treatment) or normal saline (placebo) group. In the treatment group at the 1-, 3- and 6-month evaluation the NIH-CPSI total and subscale scores, and the AUA-SS, VAS and QoL scores, along with frequencies of diurnal and nocturnal urinations, had significantly improved compared with baseline values (P < 0.05). By contrast, in the placebo group, none of these values showed improvement and the values were significantly different from those in the treatment group. Although the differences between the two groups in AUA-SS and frequencies of nocturnal urination were not significant at 1-month follow-up, repeated-measure analysis showed significant improvement in each of these values over the entire follow-up period in the treatment group. The most prominent improvement was related to the pain subscale score, which decreased by 64.76, 75.63 and 79.97% at 1, 3 and 6 months after treatment compared with baseline, followed by the VAS score, which decreased by 62.3, 72.4 and 82.1% at each follow-up, respectively. Only two patients developed mild transient gross haematuria, which was managed conservatively.

Conclusions: Transurethral intraprostatic BoNT-A injection maybe an effective therapeutic option in patients with CP/CPPS as it reduces pain and improves QoL.