Is botulinum toxin type a intraprostatic injections really effective in patients with urinary retention?

Botulinum toxin type A is used in treatment of bladder hyperactivity and sphincter dyssynergia and was reported to alleviate lower urinary tract symptoms in patients with BPH. Some authors, however, failed to observe in their study apoptosis after BoNTA administration. We conducted an open-label study of BoNTA in men with BPH-related LUTS who were unsuitable for surgery as well as investigation of the effect of the toxin on in vitro growth of fibroblasts. In the clinical part, 5 patients aged from 75 to 88, suffering from BPH and UR were treated. Patients were previously disqualified from surgery and had not passed trials without catheters (TWOC). Prostate volume ranged from 38 to 104 mL. Botulinum toxin injection were performed. Each lobe of adenoma was injected with 100 U Botox under sonographic guidance. Prostate volume and TWOC were performed after 6 months. In the in vitro part, 3T3 mouse fibroblasts and fibroblasts isolated from human prostate were cultured in the presence of Botox (10, 5 and 1 U/mL) for 24 and 72 h. Cells were detached and counted in Neubauer chamber using trypan blue assay. Cells cultured in medium without botulinum toxin were the control group. Results are presented as the means with standard deviations. The means were compared, p <0.05 was considered statistically significant.No early complications were observed. Prostate volume remained unchanged after six months and patients were unable to void. Number of 3T3 cells after 24 h incubation was 7.12 +/- 1.88, 7.12 +/- 0.64, 6.75 +/- 1.28 and 6.88 +/- 0.83 x 10(4), after 24 h, 24.00 +/- 3.46, 22.75 +/- 3.73, 23.12 +/- 3.46 and 23.88 +/- 2.42 x 10(4) after 72 h, for 0, 1, 5 and 10 U/mL botulinum toxin type A concentrations, respectively. Similarly, number of prostate fibroblasts was 7.50 +/- 1.20, 7.12 +/- 1.73, 6.50 +/-1.93, and 6.25 +/- 1.58 x 10(4) after 24 h and 9.62 +/- 2.00, 9.12 +/- 1.55, 9.12 +/- 1.73 and 9.75 +/- 2.82 x 10(4) after 72 h. In conclusion, Botox had no statistically significant, dose-dependent effect on neither 3T3 nor prostate fibroblasts proliferation. It caused no improvement in UR nor prostate volume reduction.