Response to tibial and sacral nerve modulation in overactive bladder: Is there any correlation?

To assess the correlation between the response to transcutaneous tibial nerve stimulation (TTNS) and subsequent response to sacral nerve modulation (SNM) to treat overactive bladder (OAB).

All patients who consecutively received TTNS followed by a two-stage SNM between January 2016 and June 2022 to treat OAB in two university hospital centers were included. The response to each therapy was evaluated with success defined by a 50% or greater improvement in one or more bothersome urinary symptoms from baseline. The primary endpoint was the statistical relationship between the response to TTNS and the response to SNM, assessed by logistic regression. Secondary endpoints were the statistical relationship between the response to TTNS and the response to SNM when controlling for gender, age (<57 years vs. >57 years), presence of an underlying neurological disease, and presence of DO, adding the factor and interaction to the previous regression model.

Among the 92 patients enrolled in the study, 68 of them were women (73.9%), and the median age was 57.0 [41.0-69.0] years. The success was reported in 22 patients (23.9%) under TTNS and 66 patients (71.7%) during the SNM test phase. There was no statistical correlation between response to TTNS and response to SNM in the overall population (confidence interval: 95% [0.48-4.47], p = 0.51). Similarly, there was no statistical correlation when controlling for age <57 years or ≥57 years, with p = 1.0 and p = 0.69, respectively. No statistical study could be conducted for the other subpopulations due to small sample sizes.

The response to TTNS does not predict the response to SNM in the treatment of OAB. TTNS and SNM should be considered as separate therapies, and the decision-making process for OAB treatment should take this into account.