Does response to percutaneous tibial nerve stimulation predict similar outcome to sacral nerve stimulation?

AIMS: Percutaneous tibial nerve stimulation (PTNS) is a simple neuromodulation technique to treat an overactive bladder. It is unclear whether the response to PTNS would suggest a similar response to sacral nerve stimulation (SNS), and whether PTNS could be utilized as an alternative test phase for an SNS implant. This study assessed whether PTNS response was a reliable indicator for subsequent SNS trials. METHODS: We performed a retrospective review of the hospital databases to collect all patients who had PTNS and who subsequently had an SNS trial in two tertiary hospitals from 2014 to 2020. Response to both interventions was assessed. A 50% reduction in overactive symptoms (frequency-volume charts) was considered a positive response. McNemar's tests using exact binomial probability calculations were used. The statistical significance level was set to 0.05. RESULTS: Twenty-three patients who had PTNS subsequently went on to a trial of SNS. All patients except one had previously poor response to PTNS treatment. Eight of them also failed the SNS trial. However, 15 patients (including the PTNS responder) had a successful SNS trial and proceeded with the second-stage battery implantation. The difference in response rates between the PTNS and SNS trial was statistically significant (p < 0.001). CONCLUSIONS: Poor response to PTNS does not seem to predict the likelihood of patients responding to SNS. A negative PTNS trial should not preclude a trial of a sacral nerve implant. The predictive factors for good and poor responses will be the subject of a larger study.

Predicting a successful outcome in sacral neuromodulation testing: Are urodynamic parameters prognostic?

AIMS: To assess whether the urodynamic parameters of mean voided volume, peak detrusor overactivity (DO) pressure, bladder compliance, capacity, and volume at first detrusor overactivity during filling cystometry can predict a successful outcome at first stage tined lead placement (FSTLP). METHODS: Ninty-nine consecutive patients with urodynamically proven idiopathic detrusor overactivity (IDO) refractory to medical treatment and opting for Sacral Nerve Stimulation (SNS), were assessed pre and post FSTLP. Data from 3-day frequency-volume charts, and patient reported (subjective) outcomes were used to assess success or failure after FSTLP. Success was defined as improvement in symptoms >50%. Binary logistic regression analysis was used to ascertain whether key parameters at filling cystometrogram were predictors for success prior to FSTLP. RESULTS: Binary logistic regression analysis did not demonstrate any significant relationship between the five parameters at urodynamics and outcome at FSTLP (B < 0.01, P > 0.16) for all parameters. CONCLUSIONS: The results from this prospective analysis on patients with IDO refractive to medical therapy referred for SNS would suggest that aside from proving DO at urodynamics as a pre-requisite for intervention as per NICE and EAU guidelines, no parameter is predictive for a successful outcome at FSTLP.

The cost-effectiveness of sacral nerve stimulation (SNS) for the treatment of idiopathic medically refractory overactive bladder (wet) in the UK.

OBJECTIVE: To estimate the long-term cost-effectiveness of specialised treatment options for medically refractory idiopathic overactive bladder (OAB) wet. PATIENTS AND METHODS: The cost-effectiveness of competing treatment options for patients with medically refractory idiopathic OAB wet was estimated from the perspective of the National Health Service in the UK. We compared sacral nerve stimulation (SNS) with percutaneous nerve evaluation (PNE) or tined-lead evaluation (TLE) with optimal medical therapy (OMT), botulinum toxin type A (BoNT-A) injections, and percutaneous tibial nerve stimulation (PTNS). We used a Markov model with a 10-year time horizon for all treatment options with the exception of PTNS, which has a time horizon of 5 years. Costs and effects (measured as quality-adjusted life years) were calculated to derive incremental cost-effectiveness ratios (ICERs). Direct medical resources included are: device and drug acquisition costs, pre-procedure and procedure costs, and the cost of managing adverse events. Deterministic sensitivity analyses were performed to test robustness of results. RESULTS: At 5 years, SNS (PNE or TLE) was more effective and less costly than PTNS. Compared with OMT at 10 years, SNS (PNE or TLE) was more costly and more effective, and compared with BoNT-A, SNS PNE was less costly and more effective, and SNS TLE was more costly and more effective. Decreasing the BoNT-A dose from 150 to 100 IU marginally increased the 10 year ICERs for SNS TLE and PNE (SNS PNE was no longer dominant). However, both SNS options remained cost-effective. CONCLUSION: In the management of patients with idiopathic OAB wet, the results of this cost-utility analysis favours SNS (PNE or TLE) over PTNS or OMT, and the most efficient treatment strategy is SNS PNE over BoNT-A over a 10-year period.

Male incontinence: onabotulinum toxin A and sacral nerve stimulation.

PURPOSE OF REVIEW: Overactive bladder affects 10-12% of men, of which 13% are refractory to medical therapy and seek second-line treatment. This places a substantial clinical and economic burden on the National Health Service United Kingdom. RECENT FINDINGS: This review identifies current evidence for the use of onabotulinum toxin A and sacral nerve neuromodulation for the treatment of overactive bladder in patients who do not respond to optimal medical treatment. Posterior tibial nerve stimulation is not covered here. Clinical and financial implications of the treatments are reviewed. SUMMARY: The focus will remain on recently published evidence, which may be useful to clinicians managing refractory patients.