Sacral neuromodulation treating chronic pelvic pain: a meta-analysis and systematic review of the literature.

INTRODUCTION AND HYPOTHESIS: Sacral neuromodulation (SNM) is gaining popularity as a treatment option for chronic pelvic pain (CPP). Our hypothesis is that SNM is effective in improving CPP. METHODS: A systematic search was conducted through September 2018. Peer-reviewed studies using pre- and postpain intensity scores were selected. The primary outcome was pain improvement on a 10-point visual analog scale (VAS) (adjusted or de novo) in patients with CPP. Secondary outcomes included comparing SNM approaches and etiologies and evaluating lower urinary tract symptoms (LUTS). RESULTS: Fourteen of 2175 studies, evaluating 210 patients, were eligible for further analysis. The overall VAS pain score improvement was significant [weighted mean difference (WMD) -4.34, 95% confidence interval (CI) = -5.22, to-3.64, p < 0.0001)]. Regarding SNM approach, both standard and caudal approaches had significant reduction in pain scores: WMD -4.32, CI 95% = -5.32, to -3.31 (p < 0.001) for the standard approach, compared with WMD -4.63, 95% CI = -6.57 to -2.69 (P < 0.001), for the caudal approach (p = 0.75). While significant improvement in pain was observed both in patients with and without interstitial cystitis/bladder pain syndrome (IC/BPS), the observed improvement was lower in patients with (WMD -4.13, CI 95% -5.36 to -2.90 versus without (WMD -5.72, CI 95% = -6.18, to-5.27) IC/BPS (p = 0.02). SNM was effective in treating voiding symptoms (frequency, urgency, nocturia) associated with IC/BPS (all p < 0.01). CONCLUSIONS: SNM is an effective therapy for CPP in both IC/BSP and non-IC/BSP patients, with better results in non-IC/BSP patients. Outcomes of the antegrade caudal approach were comparable with the standard retrograde approach.

International Continence Society best practice statement for use of sacral neuromodulation.

AIMS: Sacral neuromodulation (SNM) is an accepted therapy for a variety of conditions. However, despite over 20 years of experience, it remains a specialized procedure with a number of subtleties. Here we present the recommendations issued from the International Continence Society (ICS) SNM Consensus Panel. METHODS: Under the auspices of the ICS, eight urologists, three colorectal surgeons and two urogynecologists, covering a wide breadth of geographic and specialty interest representation, met in January 2017 to discuss best practices for neuromodulation. Suggestions for statements were submitted in advance and specific topics were assigned to committee members, who prepared and presented supporting data to the group, at which time each topic was discussed in depth. Best practice statements were formulated based on available data. This document was then circulated to multiple external reviewers after which final edits were made and approved by the group. RESULTS: The present recommendations, based on the most relevant data available in the literature, as well as expert opinion, address a variety of specific and at times problematic issues associated with SNM. These include the use of SNM for a variety of underlying conditions, need for pre-procedural testing, use of staged versus single-stage procedures, screening for success during the trial phase, ideal anesthesia, device implantation, post-procedural management, trouble-shooting loss of device function, and future directions for research. CONCLUSIONS: These guidelines undoubtedly constitute a reference document, which will help urologists, gynecologists, and colorectal surgeons optimize their use of SNM for refractory urinary urgency and frequency, UUI, NOR, and FI.

The effect of sacral neuromodulation on pregnancy: a systematic review.

INTRODUCTION AND HYPOTHESIS: To evaluate the effects of sacral neuromodulation (SNM) on pregnancy and the impact of delivery on SNM function. METHODS: A systematic search was conducted through January 2016. We selected studies including women who had SNM and a subsequent pregnancy. RESULTS: Out of 2,316, eight studies were included, comprising 22 patients (26 pregnancies). SNM indications were Fowler's syndrome in 11, urinary retention in 6, fecal incontinence in 1, fecal and urinary urgency in 1, overactive bladder in 1, intractable interstitial cystitis in 1, and myelodysplasia in 1. SNM stayed on in 8 pregnancies. In the remaining 18 pregnancies in which the device was deactivated, 7 had recurrent urinary tract infections, including 1 with pyelonephritis and 2 who requested reactivation owing to recurrent symptoms. Outcomes were reported in 25 pregnancies, 16 had Cesarean section (CS) and 9 had vaginal delivery, including 2 operative deliveries. Out of 25, two infants had pilonidal sinus and motor tic disorder (exhibited at the age of 2 years), both from the same mother. After delivery, SNM was functioning in 15 (60%), 4 required reprogramming, and 3 required replacement (1 had recurrence of fecal incontinence after her operative delivery with evidence of displaced leads and 1 patient reported decreased SNM effects after her two CS), and 3 decided to remove the device (2 out of 3 patients were free of symptoms after SNM deactivation and requested removal). CONCLUSION: Within the current limited evidence, the decision regarding SNM activation or deactivation should be individualized. A registry for those patients is recommended.

Specific Tips for General Controversies in Sacral Neuromodulation.

The field of Sacral Neuromodulation is continually evolving and still in its infancy. Common dilemmas experienced with this therapy will be discussed in this article, including ways to avoid and manage them. The focus will be on test evaluations performed with either peripheral nerve evaluation (PNE) or staged procedure, the clinical effectiveness and safety of unilateral versus bilateral test stimulation for both the PNE and staged procedures, and best methods to determine the success of the trial phase. We will also discuss how to deal with the problem of declining efficacy of the device over time. The article presents a discussion on future technological innovations to enhance techniques and mode of positioning and use of leads, which along with a refined understanding of how neuromodulation is effective for different problems, will lead to better outcomes.

Long-term durability of percutaneous tibial nerve stimulation for the treatment of overactive bladder.

PURPOSE: The Overactive Bladder Innovative Therapy Trial during phase 1 was a randomized trial demonstrating comparable effectiveness of percutaneous tibial nerve stimulation and extended-release tolterodine during 12 weeks of therapy for frequency, nocturia, urgency, voided volume and urge incontinence episodes. In this second phase of the Overactive Bladder Innovative Therapy Trial we assessed the sustained therapeutic efficacy of percutaneous tibial nerve stimulation in subjects with overactive bladder during 1 year. MATERIALS AND METHODS: After 12 weeks subjects randomized to weekly percutaneous tibial nerve stimulation with Urgent((R)) PC were offered an additional 9 months of treatment with assessments at 6 and 12 months from baseline. Outcome measures included voiding diary data, overactive bladder questionnaires, global response assessments and safety assessments. RESULTS: A total of 33 percutaneous tibial nerve stimulation responders continued therapy with 32 and 25 subjects completing 6 and 12 months of therapy, respectively. Subjects received a mean of 12.1 treatments during an average of 263 days, with a mean of 21 days (median 17) between treatments. Subject global response assessments showed sustained improvement from 12 weeks at 6 and 12 months, with 94% and 96% of responders, respectively. At 12 months mean improvements from baseline included a frequency of 2.8 voids daily (p <0.001), urge incontinence of 1.6 episodes daily (p <0.001), nocturia with 0.8 voids (p <0.05) and a voided volume of 39 cc (p <0.05). Overactive bladder questionnaire symptom severity was significantly improved from 12 weeks to 12 months (p <0.01) as well as from 6 to 12 months (p <0.01). No serious adverse events occurred. CONCLUSIONS: Statistically significant overactive bladder symptom improvement achieved with 12 weekly percutaneous tibial nerve stimulation treatments demonstrates excellent durability through 12 months. The durability of response demonstrates the effectiveness of percutaneous tibial nerve stimulation as a viable, long-term therapy for overactive bladder.

Procedural techniques in sacral nerve modulation.

Sacral neuromodulation involves a staged process, including a screening trial and delayed formal implantation for those with substantial improvement. The advent of the tined lead has revolutionized the technology, allowing for a minimally invasive outpatient procedure to be performed under intravenous sedation. With the addition of fluoroscopy to the bilateral percutaneous nerve evaluation, there has been marked improvement in the placement of these temporary leads. Thus, the screening evaluation is now a better reflection of possible permanent improvement. Both methods of screening have advantages and disadvantages. Selection of a particular procedure should be tailored to individual patient characteristics. Subsequent implantation of the internal pulse generator (IPG) or explantation of an unsuccessful staged lead is straightforward outpatient procedure, providing minimal additional risk for the patient. Future refinement to the procedure may involve the introduction of a rechargeable battery, eliminating the need for IPG replacement at the end of the battery life.

Sacral nerve modulation in overactive bladder.

This article represents a general overview of therapies for urinary urgency, frequency, and overactive bladder, with specific emphasis on sacral neuromodulation. The history of sacral neuromodulation is discussed along with an update of the current literature. Future directions for neuromodulation of the pelvic floor also are discussed.

Randomized trial of percutaneous tibial nerve stimulation versus extended-release tolterodine: results from the overactive bladder innovative therapy trial.

PURPOSE: The Overactive Bladder Innovative Therapy trial was a randomized, multicenter, controlled study that compared the effectiveness of percutaneous tibial nerve stimulation to extended-release tolterodine. The reduction in overactive bladder symptoms along with global response assessments was evaluated. MATERIALS AND METHODS: A total of 100 adults with urinary frequency were randomized 1:1 to 12 weeks of treatment with weekly percutaneous tibial nerve stimulation or to 4 mg daily extended-release tolterodine. Voiding diaries and an overactive bladder questionnaire were completed at baseline and at the end of therapy to compare 24-hour voiding frequency, urinary urge incontinence episodes, voids causing waking, volume voided, urgency episodes and quality of life indices. Global response assessments were completed by subjects and investigators after 12 weeks of therapy. RESULTS: The global response assessment demonstrated that subject assessment of overactive bladder symptoms compared to baseline was statistically significant in the percutaneous tibial nerve stimulation arm with 79.5% reporting cure or improvement compared to 54.8% of subjects on tolterodine (p = 0.01). Assessments by investigators were similar but did not reach statistical significance (p = 0.05). After 12 weeks of therapy objective measures improved similarly in both groups for reductions in urinary frequency, urge urinary incontinence episodes, urge severity and nighttime voids, as well as for improvement in voided volume. There were no serious adverse events or device malfunctions. CONCLUSIONS: This multicenter, randomized trial demonstrates that percutaneous tibial nerve stimulation is safe with statistically significant improvements in patient assessment of overactive bladder symptoms, and with objective effectiveness comparable to that of pharmacotherapy. Percutaneous tibial nerve stimulation may be considered a clinically significant alternative therapy for overactive bladder.

Sacral neuromodulation for female pelvic floor disorders.

Objective: To systematically review available studies on the effectiveness and safety of sacral neuromodulation (SNM) in women with various pelvic floor disorders not responding to more conservative treatment, as SNM is indicated in such women. Methods: Data source: We did a systematic review through the PubMed and the Cochrane Library according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement from 1998 to 2018 in English using the keywords 'Sacral Neuromodulation' and 'Sacral Nerve Stimulation'. Study selection: Randomised controlled trials and prospective studies were selected, with a minimum sample size of 20 patients and ≥6 months of follow-up. Results: We identified 19 articles. A ≥50% reduction in symptoms qualifies the patient for a permanent implant. Several advances have been introduced into SNM to decrease the invasiveness of the procedure, including a smaller implantable pulse generator battery (improved comfort) and better localisation of the lead wire (improved outcome). The literature reports success for overactive bladder (OAB) to range between 56% and 68% (up to 80%). We report a 5-year therapeutic success rate of 67%. In our previous studies, 38% of our patients with urge urinary incontinence achieved complete continence at 60-months follow-up, with a therapeutic response rate of 57%. Effectiveness in patients with urinary retention and faecal incontinence are about 70% and 85%, respectively. Effectiveness in interstitial cystitis/bladder pain syndrome appears to be lower compared with OAB. Conclusion: SNM is a safe and effective therapy for women with various pelvic floor disorders. Abbreviations: BONT: botulinum toxin; FDA: USA Food and Drug Administration; FS: Fowler's syndrome; FI: faecal incontinence; IC/BPS: interstitial cystitis/bladder pain syndrome; ICIQ-OABqol: International Consultation on Incontinence Modular Questionnaire-Overactive Bladder Symptoms Quality of Life; INS: implantable neurostimulator; OAB: overactive bladder; PET: positron emission tomography; PNE: peripheral nerve evaluation; PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-Analyses; PTNM: posterior tibial nerve modulation; PVR: post-void residual urine; QoL: quality of life; RCT: randomised controlled trial; SNM: sacral neuromodulation; (U)UI: (urgency) urinary incontinence.

Urodynamic evaluation of sacral neuromodulation for urge urinary incontinence.

OBJECTIVE: To evaluate the urodynamic data before and 6 months after implantation of sacral neuromodulation (SNM, an established treatment for voiding dysfunction, including refractory urge urinary incontinence, UI) and to assess the correlation between the urodynamic data and clinical efficacy in patients with UI. PATIENTS AND METHODS: In all, 111 patients with a >50% reduction in UI symptoms during a percutaneous nerve evaluation test qualified for surgical implantation of SNM. Patients were categorized in two subgroups, i.e. those with UI with or without confirmed detrusor overactivity (DO) at baseline. At the 6-month follow-up all patients had a second urodynamic investigation, with the stimulator switched on. RESULTS: At baseline, there was urodynamically confirmed DO in 67 patients, while 44 showed no DO. A review of filling cystometry variables showed a statistically significant improvement in bladder volumes at first sensation of filling (FSF) and at maximum fill volume (MFV) before voiding for both UI subgroups, compared with baseline. In 51% of the patients with UI and DO at baseline, the DO resolved during the follow-up. However, those patients were no more clinically successful than those who still had DO (P = 0.73). At the 6-month follow-up, 55 of 84 implanted patients showed clinical benefit, having a >or=50% improvement in primary voiding diary variables. Patients with UI but no DO had a higher rate of clinical success (73%) than patients with UI and DO (61%), but the difference was not statistically significant. CONCLUSION: These urodynamic results show a statistically significant improvement in FSF and MFV in patients with UI with or with no DO after SNM. Although there was a urodynamic and clinical improvement in both groups, patients with UI but no DO are at least as successful as patients with UI and DO. Therefore in patients with UI, DO should not be a prerequisite selection criterion for using SNM.

Real-World Retention Rates After Intravesical OnabotulinumtoxinA for Idiopathic Overactive Bladder.

INTRODUCTION: The risk of incomplete bladder evacuation requiring catheterization after intravesical onabotulinumtoxinA (BoNT-A) is well established. However, the rates reported in the literature are highly variable and low overall in clinical trials. We attempt to evaluate the rate of symptomatic acute urinary retention requiring catheterization after initial BoNT-A in a private practice setting of patients with idiopathic overactive bladder. METHODS: We performed a retrospective study from 2010 to 2014 for patients with idiopathic overactive bladder undergoing their first BoNT-A. Demographic information recorded included age, sex, presence of diabetes, baseline postvoid residual (PVR), presence of urodynamic detrusor overactivity, bladder capacity, peak flow rate (Qmax), BoNT-A unit dose, and carrier volume. Urinary retention was defined as those patients who were symptomatic and required catheterization for a PVR of 200 mL or greater. RESULTS: Of 103 patients who received BoNT-A, 21 (20.3%) developed symptomatic retention requiring catheterization. There was no difference in baseline characteristics, preoperative PVR, and units injected (all P > 0.05). The retention group had a higher rate of bacteriuria and symptomatic urinary tract infection (all P < 0.05). Despite developing symptomatic retention requiring performance of catheterization, 47% of these patients continued with a subsequent injection of BoNT-A. CONCLUSIONS: The need for catheterization after initial delivery of intravescial BoNT-A is an adverse event that seems to be higher in our clinical practice than seen in clinical trials. This information will be critical in order to properly counsel our future patients about the risks and benefits of this therapy.

Sacral Neuromodulation in Urological Practice.

Sacral neuromodulation (SNM) is a minimally invasive, restorative treatment to improve voiding and elimination functions. We give a historical perspective of SNM and explore the evidence for the use of this therapy for Food and Drug Administration-approved pathologies as well as disease processes that are being treated internationally. Ensuring optimal lead placement increases the potential of a comfortable, durable, and efficacious response. The future of SNM aims to maximize its potential benefit, refine its use, and minimize its risks and cost. Evolution of the therapy includes better device options, better software for patient and clinician use, more programming capabilities, and new nerve targets.

Selecting patients for sacral nerve stimulation.

Patient selection for SNS remains empiric. A key is to think of voiding dysfunctions in terms of voiding behaviors and pelvic floor muscle function, not organ-based labels. Patients who have intractable urinary frequency, urgency, urge incontinence, or idiopathic urinary retention should be considered as prime candidates. Evidence of high-tone pelvic floor muscle dysfunction also may be demonstrated on routine physical examination, as well as diagnostic studies such as pelvic-floor EMG. A successful trial stimulation remains the best indicator for patient selection, and should be used as a routine diagnostic test among patients who have chronic, life-altering voiding complaints that cannot be resolved adequately by medications or behavioral interventions.

Sacral neuromodulation: Therapy evolution.

OBJECTIVES: Sacral neuromodulation has gained increased worldwide acceptance as the standard of care in patients with refractory overactive bladder (OAB) and non-obstructive urinary retention (NOUR). This review will detail the evolution of the technology. MATERIALS AND METHODS: The mechanism of action and advances in treatment, including tined lead, fluoroscopic imaging, and smaller implantable pulse generator (IPG) are reviewed. This discussion also explores expanding indications and future advances including interstitial cystitis, chronic pelvic pain, neurogenic bladder, fecal incontinence, constipation, and dysfunctional elimination syndrome in children. RESULTS: Sacral neuromodulation (SNM) exerts its influence by modulation of sacral afferent inflow on storage and emptying reflexes. The tined lead allows for placement and stimulation to be performed in the outpatient setting under local anesthesia with mild sedation. Lead migration has been minimal and efficacy improved. The use of fluoroscopy has improved accuracy of lead placement and has led to renewed interest in bilateral percutaneous nerve evaluation (PNE). Bilateral PNE can be performed in the office setting under local anesthesia, making a trial of therapy less expensive and more attractive to patients. A smaller IPG has not only improved cosmesis, but decreased local discomfort and need for revision. The role for SNM continues to expand as clinical research identifies other applications for this therapy. CONCLUSIONS: Our understanding of SNM, as well as technological advances in therapy delivery, expands the pool of patients for which this form of therapy may prove beneficial. Less invasive instrumentation may even make this form of therapy appealing to patients without refractory symptoms.

Sacral nerve stimulation for voiding dysfunction: One institution's 11-year experience.

AIM: The purpose of this study was to review our institution's 11-year experience with SNS for the treatment of refractory voiding dysfunction. Dating back to 1993, it covers a span of time which describes the evolution of SNS as it includes PNE trials, non-tined (bone-anchored or fascial-anchored) leads, percutaneous tined leads with two-staged procedures, and even percutaneous pudendal trials. METHODS: A retrospective review was performed on SNS patients who received an implantable pulse generator (IPG) in our practice from 12/1993 to 12/2004. After Institutional Review Board approval, consents for chart review were obtained from 104 patients, representing 44% of this neuromodulatory patient population. RESULTS: Of our population, 87% were female and 13% were male. Average age at implant was 50 years +/- 13.4 years. Duration of symptoms before implantation was 116 months (range 9-600 months). Eighty percent were implanted for a predominant complaint of urinary urgency and frequency (U/F). Overall, 22% had U/F only, 38% had concomitant urge incontinence (UI), and 20% had concomitant mixed incontinence (MI). Twenty percent were treated for non-obstructive urinary retention (UR), with half of these associated with a neurogenic etiology. Additionally, 46.2% had pelvic pain, 58.6% had bowel complaints, and 51% reported sexual dysfunction. In patients with U/F, mean voiding parameters as described by pre-implant voiding diaries revealed the following: 12.4 (+/-5.1) voids per 24 hr; 2.3 (+/-1.8) voids per night; 5.0 (+/-4.7) leaks per 24 hr; and 2.3 (+/-2.6) pads per 24 hr. Statistically significant improvements post-implantation were noted with mean decreases in the following: 4.3 voids per 24 hr; 1.0 void per night; 4.4 leaks per 24 hr; and 2.3 pads per 24 hr (all P < 0.05). In the UR group a statistically significant improvement post-implantation was noted only in voids per night, with a mean decrease of 0.8 (P < 0.05). With a mean follow up of 22 months (range 3-162 months), sustained subjective improvement was >50%, >80%, and >90% in 69%, 50%, and 35% of patients, respectively. By quality of life survey, 60.5% of patients were satisfied and 16.1% were dissatisfied with current urinary symptoms. Only 13% (14 patients) abandoned therapy, making up a significant portion of those dissatisfied with current urinary symptoms. Good overall lead durability was seen (mean 22 months, range 1-121 months), with the first successful lead proving to be the most durable (mean 28 months, range 1.4-120 months). Lead durability decreased progressively with subsequent trials. Overall, 53% of patients experienced at least one reportable event (RE) attributable to either lead or IPG. A total of 126 REs were noted, with 97% mild-to-moderate in severity. REs included lack of efficacy, loss of efficacy, infection, hematoma/seroma, migration, pain, undesirable change in sensation, and device malfunction. In this population, 47.1% of leads were tined while 52.9% were non-tined. Tined leads had an overall lower RE rate as compared to non-tined leads: 28% and 73%, respectively. CONCLUSIONS: SNS is an effective method for treating certain types of voiding dysfunction. Although 53% of patients experienced at least one RE, 97% were mild-to-moderate and did not appear to affect the continued use of this therapy. With improved technology, such as percutaneous tined leads, the RE rate is decreasing. Further analyses of subsets of this population are currently underway.