Intraprostatic injection of botulinum toxin-A in patients with refractory chronic pelvic pain syndrome: The transurethral vs. transrectal approach

Objective:
To evaluate the outcome of an intraprostatic injection of botulinum toxin-A (BTX-A) in men with refractory chronic prostatitis-associated chronic pelvic-pain syndrome (CP/CPPS) and to compare the efficacy of the transurethral and transrectal routes.

Patients and methods:
In an uncontrolled randomised clinical trial conducted in men with refractory CP/CPPS, the patients were classified into two groups according to the route of BTX-A injection; transurethral (group 1, 28 patients) and transrectal ultrasonography-guided (group 2, 35 patients). The chronic prostatitis symptom index (CPSI), maximum urinary flow rate (Qmax) and white blood cell (WBC) count in expressed prostatic secretion (EPS) were measured before and at 3, 6 and 12 months after the injection. A significant clinical improvement (SCI, defined as a reduction of 4 points or a 25% decrease in total CPSI score) was correlated with patient age, prostate volume and symptom duration.

Results:
In group 1, the pain and quality-of-life domain scores improved, but statistically significantly only at 6 months. The voiding score improved at all follow-up visits. In group 2 there was a significant improvement in all the CPSI domain scores at all follow-up visits, except for pain, which was insignificantly improved by 12 months. The SCI ratings in groups 1 and 2 were 36%, 79% and 57%, and 49%, 89% and 74% in group 2 at the three follow-up visits, respectively. The Qmax was significantly improved in both groups during the follow-up (except at 12 months in group 1). There was a significant reduction in the mean WBC count in the EPS in patients with inflammatory prostatitis. Both prostate volume and symptom duration were significantly associated with a lower SCI rating.

Conclusion:
BTX-A is an available treatment option for patients with refractory CP/CPPS. It is more effective in patients with a small prostate and short symptom duration. The transrectal route provided better results than the transurethral route. More prospective longer term studies are needed.