A Supervised 3 Weeks Test Phase in Sacral Neuromodulation with a 1-Year Followup.

Abstract

We sought to determine whether prolonged interventional test phase increases cumulative success rate and compared success rates between early responders (ie within 1 week) and those in need for reprogramming (due to lack of efficacy) of sacral neuromodulation after 1-year followup. In a single tertiary center prospective study (August 2015 to November 2018) 90 patients refractory to first line treatment were eligible for sacral neuromodulation, including 48 overactive bladder wet (53%), 8 overactive bladder dry (9%) and 34 nonobstructive urinary retention (38%). Patients were evaluated at weekly intervals during test phase and those not successful were reprogrammed. This could be repeated after the second week. Primary outcome was success rate after 3-week test phase and after 1-year followup. Statistical analysis was done by nonparametric tests for numeric (Mann-Whitney U) and categorical (chi²) data. After 3 weeks of test period 56 patients (62%) were considered successful. Prolonged interventional testing increased cumulative success. A 1-year followup showed no significant difference in success rate between early responders and those in need for reprogramming (chi², p=0.562). There was no difference in age (Mann-Whitney U, p=0.222), sex (chi², p=0.952) or indication (chi², p= 0.975). A 3-week test phase with close followup increases cumulative success rate. During this supervised 3-week test phase 42% of the initial nonresponders after the first week became successful candidates after reprogramming. Patients who required this additional programming did equally as well as those without need for reprogramming. A supervised 3-week test phase is therefore strongly recommended.