Do baseline urodynamic parameters affect the treatment outcome after intravesical 100 U onabotulinumtoxinA injection in patients with idiopathic detrusor overactivity?

ObjectivesIntravesical injection of onabotulinumtoxinA (BoNT-A) provides effective treatment for idiopathic detrusor overactivity (IDO). However, not all patients have successful long-term therapeutic effects. This study investigated the effects of baseline urodynamic parameters on the therapeutic outcome, after injecting 100 U BoNT-A in patients with IDO.Materials and MethodsA total of 174 patients who received a first single intravesical BoNT-A 100 U injection for refractory IDO were included. A successful outcome was defined as an improvement of at least two points on a patient perception of bladder condition scale, which was scored from 0 to 6. The short-term (3 months) and long-term (up to 24 months) success rates were analyzed according to baseline urodynamic parameters, including cystometric bladder capacity, maximum flow rate, postvoid residual, voiding efficiency, and detrusor overactivity (DO) subtypes. BoNT-A- related adverse events were also reported.ResultsA successful outcome was reported by 138 (79.3%) patients at 3 months. The baseline urodynamic parameters did not affect the success rates, except that patients with phasic DO had a significantly higher success rate at 3 months than patients with terminal DO. Patients with a baseline postvoid residual (PVR) > 100 mL, had higher rates of acute urinary retention and need to strain to void. However, long-term success rates up to 24 months showed no significant differences between patients with different urodynamic parameters.ConclusionsExcept for patients with phasic DO, the baseline urodynamic parameters did not affect the treatment outcome of intravesical injection of 100 U BoNT-A for IDO. However, acute urinary retention and difficult urination occurred more often in patients with a baseline PVR of > 100 mL.