Objective: To evaluate the effect of transrectal ultrasound guided trasnperieal route injection of botulinum toxin to the external urethral sphincter in treating spinal cord injury patients with detrusor external sphincter dyssynergia.
Methods: Twenty suprasacral spinal cord injured patients with pure detrusor external sphincter dyssynergia was enrolled in this study. A single dose of 100 IU botulinum toxin was applied into the external urethral sphincter via transrectal ultrasound guided trasnperineal route injection. Outcome measurements included maximal detrusor pressure, maximal urethral pressure, detrusor leak point pressure, integrated electromyography (EMG), and maximal pressure on static urethral pressure profilometry obtained 4 weeks post-treatment. Post-voiding residuals were checked pre- and post-injection.
Results: There were significant reductions in integrated EMG and static and dynamic Pure but not in detrusor pressure and detrusor leak point pressure after treatment. Post-voiding residuals was significantly decreased at the all of the evaluation periods. In the sub-group analysis, patients with good effect had significantly lower baseline Integrated EMG (p<0.05).
Conclusions: Transrectal ultrasound is an effective tool to visualize the lower urinary tract. It also allows precise identification of the site for botulinum toxin, reducing blind attempts at localization. This study demonstrates the effect of transrectal ultrasound guided transperineal route injection of botulinum toxin in detrusor external sphincter dyssynergia. . Integrated EMG is a good evaluation tool for the net effect and dosage of botulinum toxin. Patients with severe spasticity over the external urethral sphincter may require repeated injections or higher doses.