Sacral neuromodulation (SNM) is an established treatment for refractory lower urinary tract dysfunctions (LUTDs), including overactive bladder (OAB) and non obstructive chronic urinary retention (CUR). Long term clinical efficacy often requires post implant reprogramming of stimulation parameters or electrode configuration; however, predictors of reprogramming frequency remain poorly defined. The primary aim of this study was to identify patient  and disease related predictors of SNM reprogramming using the InterStim™ X system (Medtronic).

This was a retrospective cohort study conducted at a tertiary university urology center. A total of 58 consecutive patients implanted with the InterStim™ X system for refractory OAB or CUR between 2023 and 2025 were included. The median follow up was 28 months (range 4–36). The cohort comprised 20 men (34.5%) and 38 women (65.5%), with a median age of 59 years (IQR 17). Etiology was neurogenic in 25 patients (43%) and idiopathic in 33 (57%); LUTD diagnosis was OAB in 23 patients (40%) and CUR in 35 (60%). Diabetes mellitus (DM) status was recorded as absent in 52 patients (90%), non–insulin dependent in 5 (9%), and insulin dependent in 1 (2%). Reprogramming events were defined as any change in electrode configuration and/or stimulation parameters (amplitude 0.5–12 mA; frequency 10–24 Hz) during routine follow up or for symptom deterioration. The reprogramming rate was calculated as events per patient year. Clinical efficacy was assessed using the UDI 6 questionnaire administered before implantation and at last follow up. Statistical analyses were stratified by age (<65 vs ≥65 years), etiology (neurogenic vs idiopathic), LUTD type (OAB vs CUR), and DM status. Poisson regression was used to identify predictors of reprogramming, with results expressed as incidence rate ratios (IRRs) and 95% confidence intervals (95% CI). The Wilcoxon signed rank test was applied to compare pre  and post implant UDI 6 scores. A p value <0.05 was considered statistically significant.

The mean reprogramming rate across the cohort was 0.83 events per patient year (median 0.5; range 0–4). No reprogramming was required in 41 patients (71%), whereas 17 patients (29%) underwent at least one reprogramming session. UDI 6 scores significantly improved from a median of 10.0 pre implant to 2.0 at last follow up (mean reduction −8.8 points; p<0.001), representing an average 75% reduction in urinary symptom burden. In Poisson regression, age was the only independent predictor of reprogramming frequency (IRR 1.02 per year; 95% CI 1.002–1.038; p=0.034), indicating that each additional year of age is associated with a 2% increase in the likelihood of requiring reprogramming. Patients with OAB showed a non significant trend toward higher reprogramming rates compared with those with CUR (IRR 1.55; p=0.115). Neurogenic etiology and DM (either insulin  or non–insulin dependent) did not significantly affect reprogramming needs.

Increasing age independently predicts a higher need for post implant reprogramming with the InterStim™ X system, possibly reflecting age related changes in tissue impedance, sacral nerve conduction, or patient reported thresholds. In contrast, LUTD type, neurogenic etiology, and diabetes status did not significantly influence device stability or reprogramming frequency. The absence of correlation between reprogramming intensity and symptom improvement suggests that reprogramming primarily serves a preservative role, maintaining rather than further augmenting the therapeutic effect once an optimal stimulation setting is achieved.

SNM with the InterStim™ X system provides long lasting symptom relief in refractory OAB and CUR. Older age is an independent predictor of higher reprogramming requirements, which should be considered when planning individualized follow up strategies. LUTD type, neurogenic etiology, and diabetes do not appear to significantly affect device stability. These findings support age tailored post implant management and warrant validation in larger multicenter prospective cohorts.