The overactive bladder syndrome (OAB) induces a significant decrease in the health related quality of life (HRQoL) and in some cases might pose a significant threat to the life of the patient. Botulinum toxin is used as a third-line therapy for such patients and it is proved to be both safe and effective. Our aim was to overview the data regarding response, adverse events and retreatment rates over the last ten years in our primary center.

We performed a retrospective review of the charts of our patients who received intradetrusorian injections with abobotulinum toxin type A (Dysport, IPSEN, UK). Only those patients with at least two injections and at least one follow up visit after the last injection were included in the final analysis. We analyzed the data of the cases treated between 2013 and 2022. In all cases we started with 500 Speywood units, distributed via 30 injections in the detrusor, not sparing the trigone. Our analysis focused on the demographics of the series, time to retreatment, dose changes after the initial treatment and adverse events. Statistical analysis included univariate comparisons using the t-test for continuous and categorical, and multivariate analysis with logistic regression modeling.

A total of 97 patients were included, 24 males and 73 females. Demographic data shows about 1:3 male to female ratio, with a median age of 59 years old. The median BMI at the initial evaluation was 28, ranging from 15 to 48. Retreatment in the first 6 months was done in 21% (n=20) of our patients, at 6 -12 months in 54% (n=52) of cases and at more than one year in 25% (n=25). Dose escalation was not decided in 51 cases, while in 27 cases the dose was increased to 750 units while in 19 patients we used 1000 units. In all cases, while the dose was escalated, the higher dosage was used at all subsequent treatments. No significant adverse events were encountered in our series. Our statistical analysis was unable to identify any significant correlations between age or sex and time to retreatment or dose escalation. However, it seems that a lower age at the time of the initial treatment associates a higher chance for dose escalation. Increasing the dose did not led to a longer response time and did not induce more severe adverse events.

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Abobotulinum toxin A is safe and effective for the treatment of OAB syndrome. The duration of results is not influenced by the dose, but a younger age associates a higher likelihood of increasing the dosage. A detailed discussion with the patient is mandatory before such treatment.