A Supervised Three Weeks Test Phase in Sacral Neuromodulation with a One-Year Follow-Up

PURPOSE To determine whether prolonged interventional test phase increases cumulative success rate and to compare success rates between early responders (i.e. within one week) and those in need for reprogramming (due to lack of efficacy) of sacral neuromodulation (SNM) after one-year follow-up. MATERIALS AND METHODS Single tertiary centre prospective study (August 2015-November 2018) in 90 patients refractory to first line treatment eligible for SNM; 48 overactive bladder (OAB) wet (53%), 8 OAB dry (9%), 34 non-obstructive urinary retention (NOUR) (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 success rates after three weeks test phase and after one-year follow-up. Statistical analysis was done by non-parametric tests for numeric (Mann-Whitney U) and categorical (Chi2) data. RESULTS After three weeks of test period 56 patients (62%) were considered successful. Prolonged interventional testing increased cumulative success. A one-year follow-up 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 (MWU; p= 0.222), sex (Chi2; p=0.952) or indication (Chi2; p= 0.975). CONCLUSIONS A three weeks test phase with close follow-up increases cumulative success rate. During this supervised three weeks test phase 42% of the initial non-responders after the first week became successful candidates after reprogramming. Patients who required this additional programming do equally well as those without need for reprogramming. A supervised 3 weeks test phase is therefore strongly recommended.