Development of a Predictive Tool for Midterm Success of Sacral Neuromodulation in Non-Neurogenic Overactive Bladder Syndrome.

Abstract

Objectives: To identify factors that can predict both test phase and midterm success of sacral neuromodulation (SNM) in refractory non-neurogenic overactive bladder syndrome (nnOAB) based on preoperative clinical and urodynamic data.

Materials and methods: We conducted a two-center retrospective study and included all individuals with nnOAB who underwent a test phase between 2005 and 2021, with or without subsequent implantation of an SNM device. Only those with preoperative urodynamic assessment data were included. SNM success was defined as $\ge$  50% improvement in one of the bladder diary parameters, associated with $\ge$  50% symptom improvement. Individuals underwent follow-up evaluation at 2 years.

Results: In total, 191 individuals were included (163 women), 69% of whom underwent SNM device implantation. At the preoperative urodynamic exam, 115 individuals had detrusor overactivity (DO). Test phase success was associated with younger age (p = 0.009). 24-month SNM success was associated with lower maximal detrusor pressure at DO (Pdet max DO) at baseline (p = 0.045). Other predictive factors for success at 2 years were female (p = 0.03), a history of stress incontinence surgery (p = 0.01), a low maximum urethral closure pressure (MUCP) (p = 0.04), a low volume at first DO (VFDO) (p = 0.03), and a high maximum cystometric capacity (MCC) (p = 0.03). We developed a tool to predict success at 2 years. The following threshold values were significantly associated with treatment success: MUCP < 58 cmH₂O, VFDO < 170 mL, and MCC > 254 mL.

Conclusion: Age predicted test phase success. Pdet max DO, gender, history of incontinence surgery, high MUCP, MCC, and VFDO predicted midterm success of SNM in people with nnOAB.