Editorial Comment: Sacral neuromodulation for neurogenic Lower Urinary Tract Dysfunction

Liechti MD ¹, van der Lely S ¹, Knüpfer SC ^{1, 2}, Abt D ^{3, 4}, Kiss B ⁵, Leitner L, ¹, et al. NEJM Evid 2022; 1 (11). Online ahead of print

COMMENT

This is a sham-controlled, double-blind, multicenter trial, which included patients with refractory neurogenic lower urinary tract dysfunction (NLUTD) at four Swiss referral centers (¹). Patients underwent sacral neuromodulation (SNM) test phase with lead placement into the sacral foramina S3 (rarely, S4). Neurostimulator was implanted for permanent stimulation only in patients presenting ≥50% improvement in key bladder diary variables (successful test phase). For 2 months, neuromodulation was optimized using subsensory stimulation with individually adjusted parameters. Thereafter, the neurostimulator remained on or was switched off (1:1 random allocation to group SNM ON or SNM OFF, respectively) for 2 months, followed by a neurourologic reevaluation. The primary outcome was success, as defined above, of SNM compared with baseline.

Of 124 patients undergoing SNM test phase, 65 (52%) were classified as therapy responders. Of these, 60 patients were randomly assigned to the intervention. After 2 months of intervention, the SNM ON group demonstrated a success rate of 76%. In the SNM OFF group, 42% of patients showed sustained SNM effects despite their neurostimulator being switched off during the last 2 months (odds ratio, 4.35; 95% confidence interval, 1.43 to 13.21; P=0.009).

This the first well-designed RCT demonstrating that SNM effectively corrected refractory NLUTD in the short term in well-selected neuro-urological patients. The use of subsensory stimulation allowed switching off the implantable neurostimulator in the control group without jeopardizing blinding. Additionally, this study did not detect notable carryover effects (>2months), therefore supporting a need for continuous stimulation in neuro-urological patients. The heterogeneity of neurologic patient population, which precluded a disease-specific analysis, may be seen as the main limitation of this trial.

REFERENCES

• ¹
  Liechti MD, van der Lely S, Knüpfer SC, Abt D, Kiss B, Leitner L, et al.. Sacral neuromodulation for neurogenic Lower Urinary Tract Dysfunction.NEJM Evid 2022; 1 (11). Epub ahead of print.

Publication Dates

• Publication in this collection
  09 June 2023
• Date of issue
  Mar-Apr 2023