Results of Sacral Neuromodulation Therapy for Urinary Voiding Dysfunction: Five-Year Experience of a Retrospective, Multicenter Study in China

Preliminary analysis of stimulation parameters for sacral neuromodulation in different indications: a multicenter retrospective cohort study from China

BACKGROUND

Sacral neuromodulation (SNM) is an effective approach for treating lower urinary tract dysfunction (LUTD), and stimulation programming is essential for successful treatment. However, research on SNM programming for various indications is limited. Thus, the authors aimed to determine whether there were differences in the stimulation parameters for different SNM indications and the appropriate programming recommendations.

MATERIALS AND METHODS

Clinical data were retrospectively collected from patients with LUTD who underwent SNM and completed internal pulse generator implantation. The parameters with the highest patient satisfaction or the most symptom improvement during the test period were considered optimal and used to set the programming after internal pulse generator implantation.

RESULTS

After screening, 282 patients were enrolled and categorized into four groups based on the following indications: refractory overactive bladder (OAB) ( n =61), neurogenic lower urinary tract dysfunction (nLUTD) ( n =162), interstitial cystitis/painful bladder syndrome (IC/BPS) ( n =24), and idiopathic nonobstructive urinary retention (NOUR) ( n =35). When analyzing the optimal stimulus parameters, disparities in the stimulation amplitude and pulse frequency were noted among the four groups. The stimulation amplitude in the nLUTD group was higher than that in the idiopathic NOUR group ( P =0.013). Differences in pulse frequency were observed between the refractory OAB and nLUTD groups ( P <0.001) and between the refractory OAB and idiopathic NOUR groups ( P =0.001). No differences in the electrode configuration or pulse width settings existed among the four groups.

CONCLUSIONS

The stimulation parameters for SNM varied among the different indications. For the initial programming of stage I, most patients are recommended to start with stimulation amplitudes below 2 V, although patients with nLUTD may benefit from higher amplitudes. A standard pulse width of 210 μs is recommended for all patients. However, for individuals experiencing nLUTD or idiopathic NOUR, the pulse frequency can begin above the standard 14 Hz but not exceed 50 Hz.

Feasibility of Sacral Neuromodulation in Patients With Underlying Neurologic Lower Urinary Tract Dysfunction and Fecal Incontinence

OBJECTIVE

To evaluate the efficacy and safety of sacral neuromodulation (SNM) in patients with underlying neurologic conditions and compare outcomes to non-neurogenic patients.

METHODS

Between 2017-2022 patients undergoing 2-staged implantation of InterStim II were included in a single-center retrospective study. Patients were allocated into two groups: underlying neurologic conditions (group 1) or non-neurogenic (group 2). Efficacy and safety were evaluated by comparing patients' bladder/bowel logs pre- and post-operative. Patients' demographics, indications, preimplantation urodynamic study variables, surgery duration, number of postop visits, and time to revision/removal procedures were compared and included in the data analysis.

RESULTS

Sixty-seven patients (64.2% female) with a mean age of 63.23 ± 14.15years were included in the study - 16/67(23.9%) patients assigned to group 1. There is no statistically significant difference between the groups regarding the indication for the treatment. The most common indication was nonobstructing urinary retention (NOUR) in both study groups. The common neurologic pathologies were multiple sclerosis, disc disease, and spinal stenosis. Overall and subgroup (based on an indication for SNM implantation) analyses showed no significant difference in patients' demographics, the surgery duration, or the chances for clinical success with a similar follow-up period. During the follow-up, the device was removed in 4 (25.0%) and 10 (19.6%) of the patients in group 1 and group 2, respectively (P = .912). There was no significant difference between the groups in the time till InterStim II removal (P = .905). All NOUR patients with clinical success in group 1 had an improvement of at least 75% from the baseline compared to 69% of patients in group 2 (P = .42). Univariate analysis in NOUR patients demonstrated that maximal cystometric capacity below 430 mL and the presence of detrusor contraction at voiding were statistically significant predictors of successful SNM. Overall, at the end of the follow-up period, 8 (50.0%) and 29 (56.9%) patients in groups 1 and 2, respectively, were defined as clinical success (P = .775).

Remote programming in stage I sacral neuromodulation: a multicentre prospective feasibility study

OBJECTIVE

Sacral neuromodulation (SNM) has emerged as an effective therapy for refractory lower urinary tract dysfunction (LUTD). Remote programming holds promise in addressing the time and economic burdens associated with outpatient programming, especially for patients in the observation period following Stage I implant surgery (where the lead is implanted first without the pulse generator). The study aimed to explore the effectiveness and patient satisfaction of remote programming for Stage I SNM patients, and analyze the benefits patients gain from remote programming.

METHODS

This prospective study was conducted at multiple high-level clinical SNM centres in China. Patients requiring SNM implantation were enroled and divided into two groups based on patient preference: remote programming (RP) group and outpatient control (OC) group. Patient attitudes toward RP were assessed through questionnaires, and the degree of symptom improvement was compared between the two groups to explore the usability of RP.

RESULTS

A total of 63 participants from 6 centres were included in the study, with 32 belonging to the RP group. The remote programming system presents a high level of usability (98%) and willingness (satisfaction rate: 96.83%) in result of questionnaire. RP showed a significant advantage in improving patients' score of ICSI/ICPI (medianΔICSI/ICPI RP vs. OC= -13.50 vs -2, P =0.015). And slightly ameliorate urinary symptoms such as pain (medianΔVAS RP vs. OC= -1 vs 0, P = 0.164) and urgency (medianΔOBASS -2.5 vs. -1, P = 0.,229), but the difference was not statistically significant. RP did not significantly impact the quality of life of patients ( P =0.113), so do the rate of phase-two conversion ( P = 0.926) or programming parameters.

CONCLUSION

To the best of our knowledge, the presented study is the first multicenter research focusing on the remote programming of Stage I SNM patients. Through the clinical implementation and patient feedback, we demonstrate that remote programming is not inferior to in-person programming in terms of success rate, effectiveness, safety, and patient satisfaction.

Sacral neuromodulation in the management of chronic pelvic pain: A systematic review and meta-analysis

INTRODUCTION

Sacral neuromodulation (SNM) is a treatment approved for use in several conditions including refractory overactive bladder (OAB) and voiding dysfunction. Chronic pelvic pain (CPP) is a debilitating condition for which treatment is often challenging. SNM shows promising effect in patients with refractory CPP. However, there is a lack of clear evidence, especially in long-term outcomes. This systematic review will assess outcomes of SNM for treating CPP.

METHODS

A systematic search of MEDLINE, Embase, Cochrane Central and clinical trial databases was completed from database inception until January 14, 2022. Studies using original data investigating SNM in an adult population with CPP which recorded pre and posttreatment pain scores were selected. Primary outcome was numerical change in pain score. Secondary outcomes were quality of life assessment and change in medication use and all-time complications of SNM. Risk of bias was assessed using the Newcastle Ottawa Tool for cohort studies.

RESULTS

Twenty-six of 1026 identified articles were selected evaluating 853 patients with CPP. The implantation rate after test-phase success was 64.3%. Significant improvement of pain scores was reported in 13 studies; three studies reported no significant change. WMD in pain scores on a 10-point scale was -4.64 (95% confidence interval [CI] = -5.32 to -3.95, p < 0.00001) across 20 studies which were quantitatively synthesized: effects were maintained at long-term follow-up. Mean follow-up was 42.5 months (0-59). Quality of life was measured by RAND SF-36 and EQ-5D questionnaires and all studies reported improvement in quality of life. One hundred and eighty-nine complications were reported in 1555 patients (Clavien-Dindo Grade I-IIIb). Risk of bias ranged from low to high risk. Studies were case series and bias stemmed from selection bias and loss to follow-up.

CONCLUSION

Sacral Neuromodulation is a reasonably effective treatment of Chronic Pelvic Pain and significantly reduces pain and increases patients' quality of life with immediate to long-term effects.

Sacral neuromodulation remote programming in patients with refractory lower urinary tract dysfunction: China’s experience during the COVID-19 pandemic

Objectives

Sacral neuromodulation is an effective, minimally invasive treatment for refractory lower urinary tract dysfunction. However, regular postoperative programming is crucial for the maintenance of the curative effects of electronic sacral stimulator devices. The outbreak of coronavirus disease 2019 (COVID-19) limited the ability of practitioners to perform traditional face-to-face programming of these stimulators. Therefore, this study aimed to evaluate the application of remote programming technology for sacral neuromodulation during the COVID-19 pandemic in China.

Materials and methods

We retrospectively collected data including baseline and programming information of all patients with lower urinary tract dysfunction who underwent sacral neuromodulation remote programming in China after the outbreak of COVID-19 (i.e., December 2019). The patients also completed a self-designed telephone questionnaire on the subject.

Results

A total of 51 patients from 16 centers were included. They underwent 180 total remote programming visits, and 118, 2, 25, and 54 voltage, current, pulse width, and frequency adjustments, respectively, were performed. Additionally, remote switching on and off was performed 8 times; impedance test, 54 times; and stimulation contact replacement, 25 times. The demand for remote programming was the highest during the first 6 months of sacral neuromodulation (average, 2.39 times per person). In total, 36 out of the 51 patients completed the questionnaire survey. Of these, all indicated that they chose remote programming to minimize unnecessary travel because they had been affected by COVID-19. The questionnaire also showed that remote programming could reduce the number of patient visits to the hospital, save time, reduce financial costs, and would be easy for patients to master. All surveyed patients indicated that they were satisfied with remote programming and were willing to recommend it to other patients.

Conclusion

Remote programming for sacral neuromodulation is feasible, effective, safe, and highly recommended by patients with refractory lower urinary tract dysfunction. Remote programming technology has great development and application potential in the post-pandemic era.

Sacral neuromodulation treatment for urinary voiding dysfunctions: results of treatment with the largest single-center series in a tertiary referral center in Turkey

BACKGROUND

Sacral neuromodulation (SNM) is a minimally invasive treatment that modulates spinal reflexes to regulate bladder, urinary sphincter, and pelvic floor and has successfully been used in the treatment of refractory voiding dysfunctions. The aim of this study was to present our experience with SNM in a tertiary referral center with the largest number of patients and review the safety and efficacy of the procedure.

METHODS

A total of 42 patients with refractory lower urinary tract symptoms were included into the study. After an initial test period, patients who showed more than 50% improvement in their symptoms underwent the second stage of SNM. Twelve patients had overactive bladder (OAB), bladder pain syndrome/interstitial cystitis (BPS/IC) and 17 had urinary retention. The clinical success was examined during follow-up by voiding diary, urodynamics, and global response assessment.

RESULTS

Between February 2015 and December 2020, a total of 29 patients underwent stages I&II SNM procedures. The mean ages of patients in OAB/BPS group and retention group were 40 (37-57 years) and 35 (27-44 years), respectively. Mean follow-up time was at least 1 year. Overall, 58.5% success rate was observed in OAB, BPS/IC, and urinary retention groups. Global response assessment score in both groups increased significantly (p = 0.001). No statistically significant difference was found between success or failure rates when sex and age were variable parameters (p > 0.05).

DISCUSSION

SNM appears to be an effective and safe treatment option in restoring voiding dysfunctions in patients with refractory idiopathic and neurogenic voiding dysfunctions. Our initial series revealed favorable results; however, further studies with larger series and longer follow-up are needed.

Radiologically anatomic measurement analysis for the third sacral foramen and an efficient implantation protocol for sacral neuromodulation

AIMS

To define radiologically anatomic measurements for the S3 foramen and develop an efficient and straightforward implantation protocol for sacral neuromodulation (SNM) in a southern Chinese population.

METHODS

We retrospectively reviewed 793 adults without sacrococcygeal abnormalities or bony injury. We generated CT-derived three-dimensional volumetric models and collected radiologically anatomic measurements of S3 foramen. A multiple generalized linear regression model was applied to evaluate implantation protocol for SNM.

RESULTS

Height, weight, and sacral height were significantly different between enrolled patients based on sex (p < 0.001 for all), while age and sacral width were similar. The measurements L1, L2, A1, and A2 on both sides were similar, while based on sex, those of L1, A1, A2 showed significant differences [7.02 ± 0.90 (M) vs. 6.10 ± 0.99 cm (F) (p < 0.001); 83.05 ± 6.23 (M) vs. 82.08 ± 7.53° (F) (p = 0.005); and 13.31 ± 5.69 (M) vs. 11.97 ± 4.91° (F) (p < 0.001), respectively]. The multiple generalized linear regression model demonstrated that sex was a common independent factor for estimating L1, L2, A1, A2, while the consistency rate between the estimated model and actual measurements was poor. The measurements L1, L2, A1, and A2 were approximately 7.0 cm (M) versus 6.1 cm (F), 1.8 cm (M) versus 1.8 cm (F), 83° (M) versus 82° (F), and 13° (M) versus 12° (F), respectively.

CONCLUSIONS

This retrospective study indicates that the radiologically anatomic measurements for the S3 foramen have unique characteristics. Our study provides an efficient and straightforward implantation protocol for SNM, improving its use in China.

Neuromodulation for Storage Lower Urinary Tract Symptoms in Parkinson Disease: A Systematic Review

BACKGROUND

Bladder symptoms are common in Parkinson disease (PD), affecting quality of life. Medications commonly used such as antimuscarinics can cause frequently intolerable side effects, and therefore, new, better tolerated approaches are needed. Neuromodulation techniques have an established role in urologic disorders; these techniques include tibial nerve stimulation (TNS) and sacral neuromodulation (SNM), which are localized therapies lacking the side effects associated with medication.

OBJECTIVES

This study aimed to undertake a systematic review of the literature reporting the use of neuromodulation techniques for the treatment of bladder symptoms in PD and related conditions.

MATERIALS AND METHODS

A systematic search of data bases was conducted including MEDLINE, CENTRAL, and Web of Science. Studies were required to present specific outcomes for individuals with PD for neuromodulation interventions.

RESULTS

Ten primary studies were identified concerning detailed outcomes of neuromodulation on bladder symptoms in PD, including seven for TNS, one for SNM, and one using transcranial magnetic stimulation (TMS). Two further mixed cohort studies documented minimal data on individuals with PD. All studies demonstrated benefit in a range of outcome measures following neuromodulation. Two randomized sham-controlled studies were carried out using TNS, with one clearly demonstrating superiority over sham, although difficulties with achieving believable yet ineffective sham treatment are highlighted. Further studies reported limited, uncontrolled outcomes of SNM in patients with PD, demonstrating benefit.

CONCLUSIONS

Evidence from case series suggests benefit from TNS in PD, with limited literature on SNM or TMS. Placebo effect from neuromodulation is a concern, and only limited controlled data exist. Future well-designed and sham-controlled studies need to be completed to provide definitive data on the benefit of neuromodulation in PD. Definitively proving the utility of a neuromodulation modality will allow better treatment of bladder symptoms without the need for pharmacologic measures that cause side effects.

Effect of low-threshold versus high-threshold genitalia stimuli on the cystometry parameters in male rats

The cross talk between external genitalia and urinary bladder could be used as part of management to certain pathological conditions affecting urinary bladder. Since urinary bladder function is also affected by pathologies of other organs (e.g., colon and esophagus), the effect of genitalia stimuli on parameters of bladder function in normal or under different pathological conditions needs to be characterized. Cystometry recordings in male rats were used to examine the effect of low-threshold (LT) and high-threshold (HT) stimulation of the scrotum and penis on urinary bladder function. These effects were studied in intact, colon irritation (CI), and esophagus irritation (EI) groups. Although HT penile stimulation had a significant inhibitory effect on micturition reflex in all groups, CI hypersensitized the penile-bladder inhibitory reflex. In addition, LT penile stimulation had a significant inhibitory effect on micturition, which was significant in CI group only. On the other hand, HT penile stimulation in CI group significantly increased the timing parameters of cystometry. Whereas LT and HT penile stimuli in EI group had a significantly increasing effect on all pressure parameters of cystometry. The scrotal stimuli had minimal effect on bladder function in all groups except for HT scrotal stimulation in the CI group, where it had a significant inhibitory effect on micturition reflex and significantly increased the maximum pressure and pressure amplitude of micturition cycles. These results show that CI and EI exacerbate the effects of genitalia stimuli, especially penile stimuli, on urinary bladder function.

Reprogramming Sacral Neuromodulation for Sub-Optimal Outcomes: Evidence and Recommendations for Clinical Practice

Objectives

In some patients treated for urinary or fecal incontinence with sacral neuromodulation (SNM) persistence of symptoms, a reduction in efficacy or adverse effects of stimulation can occur. In such situations, further programming of the SNM device can help resolve problems. Infrequently hardware failure is detected. This article aims to provide practical guidance to solve sub‐optimal outcomes (troubleshooting) occurring in the course of SNM therapy.

Materials and Methods

A systematic literature review was performed. Collective clinical experience from an expert multidisciplinary group was used to form opinion where evidence was lacking.

Results

Circumstances in which reprogramming is required are described. Actions to undertake include changes of electrode configuration, stimulation amplitude, pulse frequency, and pulse width. Guidance in case of loss of efficacy and adverse effects of stimulation, developed by a group of European experts, is presented. In addition, various hardware failure scenarios and their management are described.

Conclusions

Reprogramming aims to further improve patient symptoms or ensure a comfortable delivery of the therapy. Initial changes of electrode configuration and adjustment of stimulation parameters can be performed at home to avoid unnecessary hospital visits. A logical and stepwise approach to reprogramming can improve the outcome of therapy and restore patient satisfaction.

Sacral Neuromodulation in Patients With Neurogenic Lower Urinary Tract Dysfunction: A Multicenter Retrospective Study From China

OBJECTIVES

This retrospective study aimed to determine the effectiveness of sacral neuromodulation (SNM) on neurogenic lower urinary tract dysfunction (NLUTD) and analyze the predictive factors.

MATERIALS AND METHODS

From January 2012 to January 2020, 152 subjects with NLUTD from four medical centers in China received SNM test stimulation. Subjects were assessed via bladder diaries, postvoid residual volumes (PRVs) and neurogenic bowel dysfunction (NBD) scores before and during the testing period. Patients who showed a minimum 50% improvement in symptoms through the SNM test phase were eligible for permanent SNM implantation.

RESULTS

The pooled success rate for chronic urinary retention was 31.0% (40/129), which was significantly lower (p < 0.05) than the rates for frequency-urgency (64.8%, 59/91), urinary incontinence (65.2%, 30/46), and NBD score (61.7%, 82/133). The results of the risk factor analysis showed that the urinary storage symptom was a statistically significant positive predictor (p = 0.001).

CONCLUSIONS

In conclusion, SNM is an effective and reliable method for treating NLUTD, especially in patients with urinary storage symptoms. Although not all of the symptoms in every patient can be resolve, SNM still might be a superior choice together with other treatment procedures.

Systematic Literature Review and Meta-Analysis of Sacral Neuromodulation (SNM) in Patients with Neurogenic Lower Urinary Tract Dysfunction (nLUTD): Over 20 Years' Experience and Future Directions

INTRODUCTION

Sacral neuromodulation (SNM) has been used in carefully selected patients with neurogenic lower urinary tract dysfunctions (nLUTD) for over two decades.

METHODS

The aim of the current work was to perform a systematic literature review and meta-analysis of studies reporting the safety and effectiveness of SNM in patients with nLUTD (neurogenic detrusor overactivity, non-obstructive urinary retention, or a combination of both). For this purpose a systematic literature research was conducted using Embase (OvidSP), MEDLINE (OvidSP), MEDLINE In-Process Citations & Daily Update (OvidSP), MEDLINE (OvidSP) e-Pub ahead of print, Cochrane Central Register of Controlled Trials (CENTRAL), NIH Clinicaltrials.gov, and WHO International Clinical Trials Registry Platform (ICTRP) between 1998 and March 2020, supplemented by a hand search.

RESULTS

Forty-seven studies were included in the systematic literature review. Twenty-one studies comprising a total of 887 patients were included in the meta-analysis of test SNM. The pooled success rate of SNM test stimulation was 66.2% (95% CI 56.9-74.4). Depending on neurogenic conditions test success rates varied greatly. Twenty-four studies with a total of 428 patients were included in the meta-analysis of permanent SNM. The success rate of pooled permanent SNM was 84.2% (95% CI 77.8-89.0). Among the identified studies, the most common adverse events (AEs) were loss of effectiveness, infection, pain at implant site, and lead migration with AE rates of 4.7%, 3.6%, 3.2%, and 3.2%, respectively. Limitations entail lower level of evidence (Oxford classification 3-4) of included studies, significant risk of bias, small sample sizes in some studies, the inclusion of retrospective case series, substantial between-study heterogeneity, heterogeneous patient populations, insufficient disease classification, and variations in terms of outcome parameters as well as techniques. Furthermore, long-term data are limited.

CONCLUSION

This meta-analysis supports not only the benefits of permanent SNM for various nLUTDs but also high overall success rates, similar to idiopathic patients. Current data of the analyzed studies showed that SNM is safe for these patients. However, more vigorous studies and/or registries are needed before definitive conclusions can be drawn.

Neuromodulation of the Pudendal Nerve Assisted by 3D Printed: A New Method of Neuromodulation for Lower Urinary Tract Dysfunction

Electrical stimulation of peripheral nerves by implanted electrodes is an effective treatment for certain pelvic floor diseases. As well as intravesical electrical stimulation, this predominantly includes stimulation of the sacral nerve, tibial nerve, and pudendal nerve. The pudendal nerve is one of the main nerves that stimulate pelvic floor muscles, external urethral meatus, and the anal sphincter and pelvic organs, and it may have effects on frequent urination, urgency, dysuria, and perineal pain. It is difficult to locate because of its anatomical course, however, leading to difficulties fixing the electrode, which increases the difficulty of pudendal nerve electrical stimulation in clinical practice. In the current study 3D printed navigation was used to solve these problems. Combined with autopsy data and patient pelvic and nerve data, a personalized design was generated. Neural modulation of the pudendal nerve was achieved by implanting the lead with the guidance of 3D printed navigation. 3D printed navigation can maximize the phase II conversion rate, reduce the difficulty of surgery, shorten the operation time, reduce damage to additional organs and blood vessels, and increase the accuracy of electrode implantation, and it can be performed while the patient is awake. It is an accurate, reversible, efficient, and minimally invasive surgery.

Long-term Outcomes of Sacral Nerve Stimulation in Pelvic Floor Dysfunctions

Purpose

The aim of this study was to analyze the long-term outcomes of sacral nerve stimulation (SNS) in both idiopathic and neurogenic pelvic floor disorders in patients treated at a referral center.

Methods

This retrospective observational study analyzed the records of 106 patients tested at our department from December 1999 to January 2017. The efficacy variables evaluated were the Global Response Assessment (range, 0%–100%) and, according to the clinical indication, other specific variables such International Consultation on Incontinence QuestionnaireShort Form, number of catheterizations or pads/day, and the numerical pain scale. The safety variables analyzed were complications (pain, migration, infection), reinterventions and explants. Patients’ quality of life (QoL) and satisfaction with the procedure were evaluated through telephone interviews.

Results

The clinical indications were overactive bladder (OAB) (n=36), urinary retention (UR) (n=37), bladder pain syndrome/interstitial cystitis (BPS/IC) (n=19), fecal incontinence (FI) (n=8), and double incontinence (DI) (n=6). The implant rates according to the clinical indication were as follows: OAB, 55.6%; UR, 56.8%; BPS/IC, 63.15%; FI, 87.5%; and DI, 66.7%. Clinical and/or statistically significant improvements in all efficacy variables were observed. Loss of therapeutic effect at 75 months of follow-up was observed in 34% of patients. Device-related pain appeared in 25 patients (39%); in 20 patients, it was resolved by reprogramming and 5 patients required device removal. An overall improvement in QoL and high levels of satisfaction with the procedure were observed. More than 90% of patients would recommend SNS to a friend or relative.

Conclusions

SNS is a minimally invasive procedure that offers a real alternative to patients with refractory pelvic floor dysfunction. Its safety profile is very favorable and it provides a long-lasting improvement in symptoms and QoL.

Variable- versus constant-frequency sacral neuromodulation in black-zone overactive bladder patients: a study protocol for a multicenter, prospective, randomized, blind, self-controlled trial

Background

The curative effect of sacral neuromodulation (SNM), used to treat overactive bladder (OAB) patients, is definite. However, some patients still have recurrent symptoms after SNM and unsatisfactory symptom improvement after repeated adjustments of the stimulation parameters combined with oral drugs. These are referred to as black-zone OAB patients. The described SNM is the standard method, which involves a constant-frequency stimulation (CFS) of the patient's specific sacral nerve. A new treatment strategy, which combines the advantages of high-frequency and low-frequency stimulations to generate variable-frequency stimulation (VFS), has not yet undergone a formal randomized clinical trial. Therefore, we designed this clinical trial to evaluate the efficacy and safety of VFS-SNM and CFS-SNM in the treatment of black-zone OAB patients.

Methods

We designed a multicenter, prospective, randomized, blinded, self-controlled trial with a 12-week follow-up period. The trial randomly divides the enrolled patients into CFS-SNM and VFS-SNM groups. The main evaluation index is the comparative effectiveness of VFS-SNM and CFS-SNM at the last follow-up. The secondary evaluation indices include the change in the OAB symptom score, the quality of life (QOL) score, and the visual analog scale compared with the baseline period at each follow-up time point.

Discussion

Previous studies and our pre-experimental results suggest that black-zone OAB patients may benefit from VFS-SNM. Twelve weeks of VFS-SNM are effective in 40%, and the non-inferior cutoff value is 10% (80% power, 0.05 significance level, 20% loss to follow up). Thus, the calculated sample size is 37 cases each for CFS and VFS groups. The trial is expected to be carried out in 18 centers, but centers will be added or removed as appropriate depending on specific implementation conditions. Clinical researchers at each center will be responsible for screening qualified participants. This is the first randomized controlled trial to comprehensively evaluate the efficacy and safety of VFS-SNM in black-zone OAB patients, which will provide high-quality clinical evidence and may provide new clinical options for such patients.

Trial registration

Chinese Clinical Trial Registry: ChiCTR2000036677, registration date: 24 August 2020.

Influence of patient sex on the effectiveness of sacral neuromodulation: A cohort study from China

BACKGROUND

Sacral neuromodulation (SNM) has been widely used to treat lower urinary tract dysfunction. Studies have shown a higher conversion rate among female patients than among male patients. However, the influence of gender on the clinical effectiveness of SNM remains unclear. We aimed to confirm whether patients of both genders show similar benefits after SNM treatment.

MATERIALS AND METHODS

Clinical data of patients with lower urinary tract symptoms associated with pelvic floor dysfunction (overactive bladder, neurogenic bladder, interstitial cystitis/painful bladder syndrome, idiopathic urinary retention) treated with SNM in 10 medical centres in China between January 2012 and December 2016 were retrospectively collected. The patients were classified by gender. Variations in objective (voiding diary) and subjective scores in the baseline, testing, and last follow-up periods were compared. Data were analysed using statistical measures.

RESULTS

The study included 203 patients (93 males, 110 females). There were no statistical differences in baseline information between the two groups, both groups showed improvement over time. Unsatisfactory improvement was observed in the quality of life and sexual life scores of both groups over the entire treatment period (all p＞0.05). Although there was a difference in the maximum voiding volume between the groups at baseline, no difference was observed at the last follow-up (p = 0.004, p = 0.044, p = 0.124), unlike in the average volume where a difference was noted at the last follow-up (p = 0.085, p = 0.964, p = 0.031). While there were no differences in quality of life, sexual life, or pelvic pain and urinary urgency frequency scores at baseline, a significant difference was observed at the last follow-up, and the degree of improvement was less among female patients (p = 0.836, p = 0.131, p = 0.015; p = 0.294, p = 0.265, p = 0.013; p = 0.299, p = 0.087, p = 0.015).

CONCLUSION

SNM treatment elicited a similar effect on patients of both gender; however, a significant difference was observed regarding patient satisfaction with the treatment. Further preoperative patient education, especially, for female patients with interstitial cystitis/painful bladder syndrome may improve patient satisfaction.

Evaluation of pre-operative bladder contractility as a predictor of improved response rate to a staged trial of sacral neuromodulation in patients with detrusor underactivity

PURPOSE

Sacral neuromodulation (SNM) is one of the few management options shown to improve outcomes in patients with detrusor underactivity (DU). This original research will investigate if preserved bladder contractility can predict a successful treatment with SNM.

METHODS

This is a retrospective study of a prospectively collected database of consecutive patients with DU, who had a staged SNM trial from January 2013 to December 2018, with a minimum of 12 months follow-up. The primary outcome was the success of stage 1 SNM trial.

RESULTS

In total, 69 patients with DU were followed. The median age was 67 [interquartile range (IQR) 74-55], median baseline bladder contractility index (BCI) 18 (IQR 67-0), and median post-void residual 200 mL (IQR 300-130). There were 35 patients (51%) that responded to a SNM trial. At a median follow-up of 23 months (IQR 39-12), three were removed for poor efficacy. In patients with detrusor acontractility (DAC), six responded (33%), compared to 29 patients (57%) with BCI > 0. This was statistically significant, p value 0.03. Younger age was also a predictive factor for SNM response, p value 0.02. There were no differences noted in those with gender, neurogenic history, previous pelvic surgery, diabetes, or pre-operative voiding history.

CONCLUSION

Our study showed that patients with preserved bladder contractility are more likely to respond to a trial of SNM compared with those that have DAC. Younger age was also predictive of SNM response. UDS is the only method to accurately identify DAC patients. This information will help in patient selection and pre-operative counselling.

Clinical outcomes of sacral neuromodulation in non-neurogenic, non-obstructive dysuria: A 5-year retrospective, multicentre study in China

BACKGROUND

Management of non-neurogenic, non-obstructive dysuria represents one of the most challenging dilemmas in urological practice. The main clinical symptom is the increase in residual urine. Voiding dysfunction is the main cause of dysuria or urinary retention, mainly due to the decrease in bladder contraction (the decrease in contraction amplitude or duration) or the increase in outflow tract resistance. Sacral neuromodulation (SNM) has been used for > 10 years to treat many kinds of lower urinary tract dysfunction. It has become increasingly popular in China in recent years. Consequently, studies focusing on non-neurogenic, non-obstructive dysuria patients treated by SNM are highly desirable.

AIM

To assess the outcome of two-stage SNM in non-neurogenic, non-obstructive dysuria.

METHODS

Clinical data of 54 patients (26 men, 28 women) with non-neurogenic, non-obstructive dysuria treated by SNM from January 2012 to December 2016 in ten medical centers in China were retrospectively analyzed. All patients received two or more conservative treatments. The voiding diary, urgency score, and quality of life score before operation, after implantation of tined lead in stage I (test period), and during short-term follow-up (latest follow-up) after implantation of the implanted pulse generator in stage II were compared to observe symptom improvements.

RESULTS

Among the 54 study patients, eight refused to implant an implanted pulse generator because of the unsatisfactory effect, and 46 chose to embed the implanted pulse generator at the end of stage I. The conversion rate of stage I to stage II was 85.2%. The average follow-up time was 18.6 mo. There were significant differences between baseline (before stage I) and the test period (after stage I) in residual urine, voiding frequency, average voiding amount, maximum voiding amount, nocturia, urgency score, and quality of life score. The residual urine and urgency score between the test period and the latest follow-up time (after stage II) were also significantly different. No significant differences were observed for other parameters. No wound infection, electrode breakage, or other irreversible adverse events occurred.

CONCLUSION

SNM is effective for patients with non-neurogenic, non-obstructive dysuria showing a poor response to traditional treatment. The duration of continuous stimulation may be positively correlated with the improvement of residual urine.