Advances in the role of sacral nerve neuromodulation in lower urinary tract symptoms

[Invasive neurostimulation in neuro-urology: state of the art]

Modulation or stimulation of the nerves supplying the lower urinary tract is a possible treatment option for dysfunction of the lower urinary tract, pelvic floor and rectum if conservative or minimally invasive treatment approaches fail. This overview shows the possibilities and limitations of sacral neuromodulation, sacral deafferentation with sacral anterior root stimulation and conus deafferentation.Sacral neuromodulation (SNM) is a procedure for the treatment of refractory pelvic floor dysfunction of various origins (idiopathic, neurogenic or post-operative), such as overactive bladder, non-obstructive retention and faecal incontinence. A particular advantage of SNM is the possibility of prior test stimulation with a high prognostic value. The procedure is minimally invasive, reversible and associated with relatively low morbidity rates.Following the introduction of MRI-compatible SNM systems, there has been renewed interest in the treatment of neurogenic bladder dysfunction. A recent meta-analysis reports similar success rates as in the idiopathic patient population.Sacral deafferentation with implantation of a sacral anterior root stimulator (SARS/SDAF) is an excellent therapeutic option for patients with spinal cord injury, which can significantly improve the quality of life of those affected and, in addition to treating neurogenic lower urinary tract dysfunction, can also have a positive effect on neurogenic bowel dysfunction, neurogenic sexual dysfunction or autonomic dysreflexia. If conservative or minimally invasive treatment fails, it is crucial for the success of this procedure to consider SDAF/SARS at an early stage in order to avoid irreversible organic damage.Conus deafferentation (KDAF) is a less invasive surgical treatment option for patients with spinal cord injury for whom sacral deafferentation would be indicated but who would not benefit from the simultaneous implantation of a sacral anterior root stimulator. In principle, these patients also have the option of being subsequently treated with an extradural implant and thus utilising the advantages of anterior root stimulation. Indications for KDAF are autonomic dysreflexia, therapy-refractory detrusor overactivity, recurrent urinary tract infections, urinary incontinence and spasticity triggered by detrusor overactivity. With KDAF, we have a safe and efficient procedure with great potential for improving the spectrum of paraplegiological and neuro-urological treatment.

Sacral Magnetic Neuromodulation with Intermittent Theta Burst Waveform Enhances Overactive Bladder: In Vivo Study

BACKGROUND

The current treatment options for overactive bladder (OAB) continue to pose challenges for refractory cases and may involve invasive procedures. To assess the potential benefit of non-invasive repetitive peripheral magnetic stimulation (rPMS) on sacral roots using intermittent theta burst stimulation (iTBS) as treatment option for OAB. The study involved a total of 33 rats, which were divided into three different experimental phases.

MATERIALS AND METHODS

To induce bladder overactivity rats were pretreated with a continuous transvesical infusion of 0.5% acetic acid (AA). During bladder infusion, the intravesical pressure was recorded using cystometrography (CMG) to investigate the effects of AA pretreatment and the therapeutic intervention of acute sacral rPMS using iTBS.

RESULTS

Pre-application of rPMS with iTBS at a 100% intensity significantly extended the mean first voiding time (Tv) in normal healthy rats to 132%. Acute rPMS iTBS at a 100% intensity resulted in a significant increase of the inter-contraction interval (ICI) to 121%. An AA model was established with continuous saline infusion after 0.5% AA treatment and resulted in significant reductions of Tv to 42% and ICI to 56% of the corresponding control values. Subsequently, rPMS iTBS at a 100% intensity on the sacral nerve effectively inhibited AA-induced bladder overactivity and significantly increased the ICI to 167%∼222%. No significant changes in maximum bladder pressure (Pmax) were found.

CONCLUSIONS

Sacral nerve rPMS with iTBS demonstrated the ability to suppress AA-induced bladder overactivity. This promising modality could be developed as an alternative approach to enhance bladder continence in OAB syndrome patients.

Sacral nerve modulation for patients with fecal incontinence: long-term outcome and effects on sexual function

Sacral nerve modulation has become an established treatment for fecal and urinary incontinence, and sexual disorders. The objective of this study was to evaluate the long-term outcome of sacral neuromodulation in patients with fecal or combined fecal and urinary incontinence (double incontinence), assessing its safety, efficacy, and impact on quality of life and sexual function. This was a multicentric, retrospective, cohort study including patients with fecal or double incontinence who received sacral neuromodulation at seven European centers between 2007 and 2017 and completed a 5-year follow-up. The main outcome measures included improvements of incontinence symptoms and quality of life compared with baseline, evaluated using validated tools and questionnaires at 1-, 6-, 12-, 36- and 60-month follow-up. 108 (102 women, mean age 62.4 ± 13.4 years) patients were recruited, of whom 88 (81.4%) underwent definitive implantation of the pacemaker. Patients' baseline median Cleveland Clinic Incontinence Score was 15 (10-18); it decreased to 2 (1-4) and 1 (1-2) at the 12- and 36-month follow-up (p < 0.0001), remaining stable at the 5-year follow-up. Fecal incontinence quality of life score improved significantly. All patients with sexual dysfunction (n = 48) at baseline reported symptom resolution at the 5-year follow-up. The study was limited by the retrospective design and the relatively small patient sample. Sacral nerve modulation is an effective treatment for fecal and double incontinence, achieving satisfactory long-term success rates, with resolution of concomitant sexual dysfunction.

Cortical, Spinal, Sacral, and Peripheral Neuromodulations as Therapeutic Approaches for the Treatment of Lower Urinary Tract Symptoms in Multiple Sclerosis Patients: A Review

INTRODUCTION

Multiple sclerosis (MS) is often associated with urological disorders, mainly urinary incontinence and retention, the management of which being necessary to improve patient's quality of life (QOL) and to reduce potential urological complications. Besides the classical treatments based mainly on anticholinergics and/or self-catheterization, several neuromodulation techniques have been tried in recent years to improve these urinary disorders. By this review, we aim at providing an overview of neuromodulation and electrostimulation approaches to manage urinary symptoms in MS patients.

MATERIALS AND METHODS

A literature search using MEDLINE was performed. Only papers in English, and describing the effects of neuromodulation in MS patients, were considered.

RESULTS

A total of 18 studies met inclusion criteria and were reviewed. Of them, four related to sacral neuromodulation (SNM), seven to percutaneous tibial nerve stimulation (PTNS), six to spinal cord stimulation (SCS), and one to transcranial magnetic stimulation (TMS).

DISCUSSION

PTNS and SNM seem to be effective and safe therapeutic options for treating lower urinary tract symptoms in MS patients principally in case of overactive bladder (OAB) symptoms. Similarly, also SCS and TMS have been shown to be effective, despite the very limited number of patients and the small number of studies found in the literature. Interestingly, these techniques are effective even in patients who do not respond well to conservative therapies, such as anticholinergics. Furthermore, given their safety and efficacy, stimulations such as PTNS could be considered as a first-line treatment for OAB in MS patients, also considering that they are often preferred by patients to other commonly used treatments.

Overlooked Long-Term Complications of Colorectal Surgery

While colorectal surgery has been documented to have some of the highest complication rates in the surgical field, some of the more common, functional complications are often overlooked in the literature and in discussion with patients. Urinary, sexual, and defecatory dysfunction are common after colorectal surgery, especially after pelvic dissections, and may severely impact the postoperative quality of life for patients. These complications include urinary retention, erectile dysfunction, retrograde ejaculation, dyspareunia, infertility, and low anterior resection syndrome. The majority is rooted in autonomic nerve damage, both sympathetic and parasympathetic, that occurs during mobilization and resection of the sigmoid colon and rectum. While not all of these postoperative complications are preventable, treatment strategies have been developed to ameliorate the impact on quality of life. Given the high incidence and direct effect on patients, clinicians should be familiar with the etiology, prevention, and treatment strategies of these complications to provide the highest quality of care.

The first Iraqi experience in sacral neuromodulation for patients with lower urinary tract dysfunction

Objectives

To present our experience, in Iraq, with sacral neuromodulation (SNM) in patients with refractory lower urinary tract dysfunction, with discussion of the factors that affect the response rate.

Patients and methods

In this prospective, clinical, interventional study, 24 patients were evaluated and treated by a team comprised of a Urologist and a Neurosurgeon with SNM over a 1.5-year period. The gender, age, pathology, and clinical presentation, were all studied and evaluated. Successful clinical response was defined as achieving a ≥50% improvement in voiding diary variables.

Results

The mean age of those that responded to SNM was 28 years, with females responding better than males (10 of 14 vs four of 10). The SNM response rate according to presentation was six of 10 in those with overactive bladder/urge urinary incontinence, six of nine of those with urinary retention, and two of five in those with a mixed presentation. The response rate in idiopathic voiding dysfunctions was 11 of 13, whilst for neurogenic dysfunctions it was three of 11. Other benefits such as in bowel motion, erectile function, menstruation, power of lower limbs, and quality of life (QoL), were also recorded. The complications were reasonable for this minimally invasive procedure.

Conclusion

SNM offers a good and durable solution for some functional bladder problems, if patients are well selected. There may also be additional extra-urinary benefits that contribute to improvements in QoL. SNM was well tolerated by our patients with an encouraging response rate, especially in psychologically stable patients with idiopathic dysfunctions.

Effects of electroacupuncture at BL33 on detrusor smooth muscle activity in a rat model of urinary retention

Background

Detrusor smooth muscle (DSM) underactivity may lead to urinary retention (UR). Electroacupuncture (EA) at BL33 may be effective in improving DSM contractions.

Objectives

This study aimed to investigate: (1) the effect of EA at BL33; and (2) the effect of different manipulation methods at BL33 on the modulation of DSM contractions in UR rats.

Methods

30 male Sprague-Dawley rats were anaesthetised with urethane and modelled by urethral outlet obstruction. First, 2 Hz EA at BL33, SP6 and LI4 wasrandomly applied to the UR rats for 5 min to observe the immediate effects (n=10); second, manual acupuncture (MA) (n=10) and 100 Hz EA (n=10) were applied with the same programme. DSM electromyography (EMG) and cystometrogram data were evaluated.

Results

(1) 2 Hz EA at BL33 and SP6 significantly increased DSM discharging frequency (0.80±0.10 Hz, P<0.001, and 0.22±0.14 Hz, P=0.038), shortened micturation intervals (65.67±20.65 s, P=0.008, and 35.62±15.84 s, P=0.042), prolonged the duration of voiding (2.13±0.61 s, P=0.005, and 0.47±0.16 s, P=0.015), and reduced residual pressure (−0.91±0.31 mmHg, P=0.019, and −0.66±0.27 mmHg, P=0.046). EA at LI4 was not associated with any functional effects (P>0.05). Compared with SP6, EA at BL33 had greater positive effects on DSM discharging frequency, duration of discharging, and duration of voiding (all P<0.05). (2) No statistically significant differences were shown between MA, 2 Hz EA and 100 Hz EA interventions when stimulating at BL33, SP6 or LI4.

Conclusions

EA at BL33 improved DSM contractions to a greater degree than EA at SP6 or LI4. There were no differences in effect when stimulating using 2 Hz EA, 100 Hz EA and MA.

Combination of sacral nerve and tibial nerve stimulation for treatment of bladder overactivity in pigs

PURPOSE

Sacral nerve and tibial nerve stimulation have been singly used to treat overactive bladder (OAB). This study evaluated the effects of both combined stimulation on treating bladder overactivity in pigs and explored a novel treatment modality for OAB.

METHODS

An implant-driven stimulator of the S3 spinal nerve was implanted in 5 pigs. The contralateral tibial nerve was stimulated by an external stimulator. Multiple cystometrograms were performed to determine the effects of single nerve stimulation and combination sacral nerve stimulation (SNS) and tibial nerve stimulation (TNS) on the micturition reflex by infusing normal saline (NS) or acetic acid (AA).

RESULTS

AA-induced bladder overactivity significantly reduced bladder capacity (BC) to 16.3 ± 2.2% of the NS control level (389.4 ± 27.68 ml; P < 0.01). When given a single stimulation, both SNS and TNS significantly increased the BC to 39.2 ± 1.6% and 34.9 ± 5.0% of the NS control level (P < 0.01), respectively. Combined SNS and TNS significantly increased the BC to 50.2 ± 5.2% of the NS control level (P < 0.01) and induced a superior inhibitory effect than SNS or TNS alone (P < 0.05).

CONCLUSIONS

Combination SNS and TNS induced a superior inhibitory effect on bladder overactivity in pigs compared to single stimulation and thus could be a novel treatment modality for OAB.

Neuromodulation of pelvic visceral pain: review of the literature and case series of potential novel targets for treatment

Chronic pelvic pain (CPP) is complex and often resistant to treatment. While the exact pathophysiology is unknown, the pain states resultant from conditions such as interstitial cystitis and the like yield patients with a presentation that bears a striking similarity to neuropathic syndromes that are known to respond to neuromodulation. While there has been past success using the sacral region as a target for spinal cord stimulation (SCS) to treat these patients, there remains to be a consensus on the optimal location for lead placement. In this article, the authors discuss the potential etiology of CPP, examine the current literature on lead placement for SCS as a method of treatment, as well as present several cases where novel lead placement was successfully employed.

Percutaneous posterior tibial nerve stimulation as an effective treatment of refractory lower urinary tract symptoms in patients with multiple sclerosis: preliminary data from a multicentre, prospective, open label trial

Background: Percutaneous tibial nerve stimulation (PTNS) has been proposed as a new, minimally invasive neuromodulation technique to treat lower urinary tract symptoms (LUTS).

Objective: To evaluate efficacy, safety and impact on quality of life (QoL) of PTNS on patients with multiple sclerosis (MS) who have LUTS.

Methods: 21 patients (5 men, 16 women) with MS and LUTS unresponsive to anticholinergics were treated with 12 sessions of PTNS. Assessment of LUTS was by validated, self-administered chart and questionnaires, testing the subjective and objective relevance of LUTS for patients and their impact on QoL before and after treatment; the mean post-micturition residual was assessed by trans-abdominal ultrasound scanning. Analysis was by intention to treat.

Results: There was a significant reduction of daytime frequency (from 9 to 6, p = 0.04), nocturia (from 3 to 1, p = 0.002) and mean post-micturition residual (from 98 ± 124 ml to 43 ± 45 ml, p = 0.02). The mean voided volume increased from 182 ± 50 ml to 225 ± 50 ml ( p = 0.003). Eighty-nine percent of patients reported a treatment satisfaction of 70%. Significant improvement in QoL was seen in most domains of the King’s Health QoL questionnaire ( p < 0.05). No adverse events were reported.

Conclusions: PTNS is an effective, safe and well-tolerated treatment for LUTS in patients with MS.

[Therapy-refractory overactive bladder: alternative treatment approaches]

The treatment of patients with overactive bladder (OAB) refractory to conventional treatment is gaining clinical significance. This article intends to review alternative therapy options for patients with OAB refractory to conventional treatment. A search of the PubMed database as well as the abstracts presented at the European Association of Urology and the American Urological Association annual meetings was conducted. Keywords used during this search included overactive bladder (OAB) refractory to conventional treatment, electromotive drug administration (EMDA), sacral neuromodulation, augmentation cystoplasty and cystectomy. Eighteen articles with an adequate number of patients were identified. All articles published before 2001 were not included in this analysis. Because of first-line treatment failure, 30% of the patients required alternative treatment. This included EMDA, botulinum toxin injections into the detrusor, sacral neuromodulation, augmentation cystoplasty or cystectomy. Based on this review it appears that a significant improvement in micturition parameters, continence and in quality of life was achieved. Overall EMDA, intradetrusor injections of botulinum toxin and sacral neuromodulation seem to be highly effective and safe. Augmentation cystoplasty or cystectomy remains the last choice of treatment in refractory cases.Overall EMDA, intradetrusor injections of botulinum toxin and sacral neuromodulation seem to be highly effective and safe. Augmentation cystoplasty or cystectomy remains to be the last choice of treatment in refractory cases.