New aspects in the treatment of detrusor-sphincter dyssynergia with botulinum toxin-A

Purpose: The paralytic effect of two types of botulinum-A toxins injections Botox(R) versus Dysport(R) on the external sphincter was investigated prospectively in neurogenic voiding disorders. Patients and methods: BTX-A injections into the external urethral sphincter (100 units Botox(R) or 250 units Dysport(R)) were performed in 10 male spinal cord injury patients with detrusor sphincter dyssynergia (DSD). Patients were reassessed clinically 4 to 6 weeks after treatment. In cases of persistent difficulty in voiding or high post-void residual volume, patients were reinjected with the same product. Patients were injected maximally 3 times with botulinum toxin-A per treatment cycle. Urodynamic examinations were carried out in all patients at least within 3 and 6 months following the last injection. If insufficient urodynamical and clinical results were found, a single reinjection of botulinum toxin was planned. If no reinjection was done, the patients were asked to come back for a new clinical and urodynamical control after 3 months. Results: 30 botulinum-A injection cycles were performed in 10 patients. One cycle consists of 1 or 2 or 3 injections and corresponds to one treatment. Considering the sequency CMG(0) (Cystomanometrography, base line) - treatment- CMC1 (first urodynamic control), there was a significant decrease in the duration of detrusor-sphincter dyssynergia (p < 0.05) after botulinum-A injections. There was a marked shortening of the time elapsing between the beginning of bladder contraction and voiding (p < 0.05) and a reversal of the DSD from a type II to a type I (p < 0.05) after treatment. All patients with residual volume before injection showed a marked decrease of it after treatment. These effects lasted at least 6 months. There was a significantly better improvement of the urodynamic parameters after Botox(R) than after Dysport(R) injections (p < 0.05). However, compared to the administered Botox(R) doses, the dosage of Dysport(R) was considered to be too low. Conclusion: Botulinum-A toxin injection into the external urethral sphincter is a valuable alternative treatment for DSD in spinal cord injury patients. From this study it appears that the quality of the results depends on the severity of the DSD prior to treatment. The more severe the DSD, the more difficult the treatment and need for repeated injections.