Neuromodulation - a therapeutic option for refractory overactive bladder. A recent literature review

Effectiveness and safety of sacral neuromodulation for neurogenic bladder

BACKGROUND

The treatment of neurogenic bladder (NB) is a challenge because conventional therapy often fails. Sacral neuromodulation (SNM) is a minimally invasive technique and an unconventional treatment for neurogenic bladder. Its research is still in the exploratory stage. The research on its effectiveness and safety is not clear.

OBJECTIVE

To assess the effectiveness and safety of sacral neuromodulation (SNM) for neurogenic bladder (NB).

METHODS

By searching the PubMed databases and Cochrane Library databases, combined with the method of literature tracing, the clinical researches and works on neurogenic bladder and sacral neuromodulation therapy were collected. Two reviewers independently selected and extracted data, (1) determine whether the study meets the inclusion criteria and exclude the literature that meets the exclusion criteria. (2) Researchers' screening results and data, if there are differences in the results, will be discussed to eliminate the differences. (3) Read the full text of the literature carefully to determine the final literature to be included. (4) The relevant data of 11 independent studies, a total of 291 patients, were systematically reviewed using review manager 5.3 software.

RESULTS

This research included 11 independent studies with a total of 291 patients. The improvements of main outcomes before and after SNM therapy were significant: incontinence episodes /24 h (WMD -2.52; 95%CI-3.14-1.90; p <0.001), frequency/24 h (WMD-5.96; 95%CI -6.27，-5.66; p <0.001), voiding volume (WMD 116.09 mL; 95%CI 86.68，145.51; p <0.001), cystometric capacity (WMD 129.84 mL; 95%CI 100.53, 159.15; p <0.001), post-void residual volume (WMD-198.00 mL; 95%CI-264.60, -131.40; p <0.001), clean intermittent self-catheterization/24 h (WMD-2.48; 95%CI -2.96, -2.00; p <0.001).

CONCLUSION

This systematic review indicated that the sacral neuromodulation treatment for neurogenic bladder was effective and safe.

Posterior Tibial Nerve Stimulation for Overactive Bladder: Mechanism, Classification, and Management Outlines

Purpose of the Review. Posterior tibial nerve stimulation (PTNS) techniques have dramatically grown after approval to manage overactive bladder (OAB). The present review will focus on the most current data on PTNS types (percutaneous, transcutaneous, and implant) and their mechanism of action, safety, efficacy, advantages, drawbacks, limitation, and clinical applications. Recent Findings. The present review described the recent studies that addressed the tibial nerve stimulation role in OAB management. BlueWind RENOVA system, Bioness StimRouter, and eCoin are examples of emerging technologies that have evolved from interval sessions (percutaneous PTNS and transcutaneous PTNS) to continuous stimulation (implants). These can be efficiently managed at home by patients with minimum burden on the health system and fewer visits, especially in the COVID-19 pandemic. Summary. Our review shows that the tibial nerve stimulation advancements in OAB treatment have been rapidly increasing over the recent years. It is minimally invasive and effective, similar to sacral nerve stimulation (SNM), but less aggressive. Implantable PTNS has been promised in terms of efficacy, safety, and high acceptance rate. However, evidence is still limited to short-term trials, and tolerability, method, and drawbacks remain challenges.

Fowler's Syndrome-The Cause of Urinary Retention in Young Women, Often Forgotten, but Significant and Challenging to Treat

Urinary retention in young women is a relatively rare clinical problem and is often underdiagnosed. In particular, functional causes of urinary retention pose a diagnostic challenge. One of them is Fowler’s syndrome, which is associated with impaired urethral relaxation. Fowler’s syndrome is characterized by a large bladder capacity, reduced sensation, increased maximal urethral closure pressure, and detrusor underactivity. Several hypotheses have arisen to explain the cause of urethral relaxation disorders: hormonal changes characteristic of Polycystic Ovary Syndrome (PCOS), causing abnormal stabilization of the muscle membrane, primary failure of relaxation of the striated muscle of the urethra sphincter, and increased urethral afferent activity, inhibiting the bladder afferent signals from reaching the brain by potentiating a spinal mechanism of urinary continence. Currently, sacral neuromodulation is the only intervention that can restore an atypical voiding pattern in women with Fowler’s syndrome. The therapeutic effectiveness exceeds 70%, although the revision rate is relatively high, exceeding 50%. Well-designed, long-term prospective studies comparing sacral neuromodulation (SNM) with other therapies such as pelvic floor muscle physiotherapy are warranted to offer the best patient-tailored treatment.