Differential effects of low- and high-frequency sacral neuromodulation on urinary symptoms: high-frequency improves Qmax, low-frequency enhances bladder capacity.

Objective: To compare the efficacy, safety, and patient satisfaction between low- and high-frequency sacral neuromodulation (SNM) in patients undergoing SNM.

Methods: This retrospective study included 263 patients treated between January 2016 and December 2022 at PLA General Hospital of Southern Theater Command. Patients received either low-frequency (≤ 16 Hz) or high-frequency (> 16 Hz) SNM. Urodynamic outcomes, quality of life, adverse events, and patient satisfaction were assessed pre- and post-treatment.

Results: Of the cohort, 128 patients received low-frequency and 135 received high-frequency stimulation. Post-treatment, the high-frequency group showed a significant improvement in maximum urinary flow rate (Qmax) and detrusor contractility compared to the low-frequency group. In contrast, the low-frequency group exhibited greater increases in maximum bladder capacity. Both groups demonstrated significant reductions in urination difficulty and waiting times, with the high-frequency group achieving more pronounced improvements. Quality of life scores and adverse event rates were similar across both groups. High patient satisfaction was noted in both groups, with no significant difference in overall satisfaction rates (P = 0.404). Correlation analysis indicated significant relationships between stimulation frequency and various urodynamic parameters, with higher frequencies generally associated with better urodynamic outcomes.

Conclusion: Both low- and high-frequency SNM improve urinary symptoms and quality of life, with high-frequency showing better urodynamic outcomes in Qmax and detrusor contractility, while low-frequency enhances bladder capacity. Both treatments are safe and highly satisfactory to patients.