Onabotulinumtoxina Re-Injection for Refractory Detrusor Overactivity Using 3-4 Injection Sites: Results of a Pilot Study.

Objective: To determine if repeated treatment with Onabot/A in less injections points, provides similar clinical efficacy, duration, and adverse events compared with previous treatment.

Methods: Prospective data of neurogenic detrusor overactivity (NDO) and idiopathic detrusor overactivity (IDO) patients previously treated with Onabot/A according to standard technique. When patients requested for repeating procedure, they were treated with the same Onabot/A dose but with 3-4 injection sites. Onabot/A injection was performed under local or spinal anaesthesia. Pain was evaluated with VAS pain scale. Efficacy was evaluated by the Treatment Benefit Scale (TBS) and attainment of complete continence. Duration of effect was determined by patient reported return of symptoms, and requested for repeating procedure. Adverse events were also reported.

Results: We report the results of 21 patients. Nineteen patients (90%) were female, 10 patients (48%) neurogenic, 9 (43%) were under clean intermittent catheterization. Procedure was performed under local anaesthesia in 20 patients (95%). Doses of Onabot/A used were 100-300 units with 3-4 injections sites. According to TBS, 86% of patients improved. Seventeen patients (81%) were continent after the procedure. Five patients (24%) presented urinary tract infection as adverse event. The mean duration of effect was 34.9 weeks compared with 35.6 weeks of previous procedure with no significant differences.

Conclusion: We consider that treatment of Onabot/A with 3-4 injections may have similar clinical efficacy and duration of effect, compared to standard technique, with limited adverse events.