A prospective study to assess the effectiveness and safety of the BlueWind System in the treatment of patients diagnosed with urgency urinary incontinence

BACKGROUND

Overactive bladder (OAB) affects one in six adults in Europe and the United States and impairs the quality of life of millions of individuals worldwide. When conservative management fails, third-line treatments including tibial neuromodulation (TNM) is often pursued. TNM has traditionally been accomplished percutaneously in clinic.

OBJECTIVE

A minimally invasive implantable device activated by a battery-operated external wearable unit has been developed for the treatment of urgency urinary incontinence (UUI), mitigating the burden of frequent clinic visits and more invasive therapies that are currently commercially available.

METHODS

A prospective, multicenter, single-arm, open-label, pivotal study evaluated the safety and effectiveness of the device in adult females with UUI (i.e., wet OAB) (BlueWind Implantable Tibial Neuromodulation [iTNM] system; IDE number #G200013; NCT03596671). Results with the device were previously published under the name RENOVA iStim, which has been since renamed as the Revi™ System. Approximately 1-month post-implantation of the device, participants delivered therapy at their convenience and completed a 7-day voiding diary before visits 6- and 12-months post-treatment initiation. The primary efficacy and safety endpoints were the proportion of responders to therapy ( ≥ 50% improvement on average number of urgency-related incontinence episodes) and incidence of adverse events from implantation to 12-month post-activation.

RESULTS

A total of 151 participants, mean age 58.8 (SD: 12.5), were implanted; 144 and 140 completed the 6- and 12-month visits, respectively. The participants demonstrated mean baseline of 4.8 UUI/day (SD 2.9) and 10 voids/day (SD 3.3). Six and 12-months post-activation, 76.4% and 78.4% of participants, respectively, were responders to therapy in an intent-to-treat analysis. Of the 139 participants with completed 12-month diaries, 82% were responders, 50% were classified as "dry" (on at least 3 consecutive diary days), and 93.5% of participants reported that their symptoms improved. No implanted participant experienced an SAE related to the procedure or device.

CONCLUSIONS

iTNM, delivered and powered by a patient-controlled external wearable communicating with an implant, demonstrated clinically meaningful and statistically significant improvement in UUI symptoms and a high safety profile. This therapy highlights the value of patient-centric therapy for the treatment of UUI.

What Is in the Pipeline on Investigational Neuromodulation Techniques for Lower Urinary Tract Dysfunction: A Narrative Review

OBJECTIVES

Overactive bladder (OAB) affects millions of patients worldwide. Its treatment is challenging but improves the patient's quality of life. Besides standard techniques for neuromodulation (sacral and pudendal neuromodulation and posterior tibial nerve stimulation), several new techniques have been investigated to treat symptoms of refractory OAB. The purpose of the present review is to outline the state of the art of new neuromodulation techniques for lower urinary tract dysfunction (LUTD).

MATERIALS AND METHODS

In March 2023, a comprehensive MEDLINE, EMBASE, and Scopus search was carried out (keywords: LUTD, new technologies, neuromodulation, LUTS, OAB, painful bladder syndromes, etc). Articles were included according to inclusion (randomized controlled trials, prospective trials, large retrospective studies) and exclusion (case reports, outcomes not clearly expressed in full text, animal studies) criteria. The reference lists of the included studies also were scanned. Both adult and pediatric populations were included, in addition to both neurogenic and nonneurogenic OAB. A narrative review was then performed.

RESULTS

Peroneal neuromodulation, transcutaneous electrical nerve stimulation, magnetic nerve stimulation, and parasacral transcutaneous neuromodulation are the most studied investigative techniques and were shown to yield promising results in treating OAB symptoms. Most studies showed promising results even in the complex scenarios of patients with OAB refractory to standard treatments. Comparing investigational techniques with standard of care and their respective clinical outcomes and safety profiles, and confronting their pros and cons, we reasonably believe that once such treatment modalities are further developed, they could play a role in the OAB treatment algorithm.

CONCLUSIONS

Although the described neuromodulation techniques are being intensely studied, the available results are not yet sufficient for any guidelines to recommend their use.

The Maximal Urethral Pressure at Rest and during Normal Bladder Filling Is Only Determined by the Activity of the Urethral Smooth Musculature in the Female

The aim of this opinion paper is to determine the entities that define the maximal urethral pressure (MUP) during rest and during bladder filling that is needed to guarantee continence in females. For the development of this opinion, the literature was searched for via the Pubmed database and historic sources. Animal studies indicate that the maximal urethral pressure is determined by the smooth muscle activity in the mid-urethra. Additionally, during increased smooth muscle tone development, the largest sympathetic responses are found in the middle part of the urethra. This could be confirmed in human studies that are unable to find striated EMG activity in this area. Moreover, the external urethral striated sphincter is situated at the distal urethra, which is not the area with the highest pressure. The external urethral sphincter only provides additional urethral pressure in situations of exertion and physical activity. From a physics point of view, the phasic pressure of the external striated sphincter at the distal urethra cannot be added to the tonic pressure generated by the smooth muscle in the mid-urethra. The assertion that mid-urethral pressure is the result of different pressure forces around the urethra, including that of the external striated sphincter, is not supported by basic research evidence combined with physical calculation and should therefore be considered a misconception in the field of functional urology.

Cost-effectiveness of urethral bulking polydimethylsiloxane-Urolastic® compared with mid-urethral sling surgery for stress urinary incontinence: A two-arm cohort study

OBJECTIVE

To investigate the cost-effectiveness of urethral bulking polydimethylsiloxane-Urolastic® (PDMS-U) compared with mid-urethral sling (MUS) surgery for stress urinary incontinence (SUI) at 1-year follow-up.

DESIGN

Prospective, two-arm cohort study with 2-year follow-up.

SETTING

International multicentre.

POPULATION

Women with moderate to severe SUI.

MAIN OUTCOME MEASURES

Primary outcome was subjective cure (Patient Global Impression of Improvement).

SECONDARY OUTCOMES

objective cure (negative cough stress test), Urogenital Distress Inventory (UDI-6), complications and re-interventions. Cost-effectiveness outcomes: total costs, quality-adjusted life year (QALY) using IIQ7-scores (Incontinence Impact Questionnaire) and EQ-5D-5L, incremental cost-effectiveness ratio (ICER) and monetary benefit (adjusted for baseline confounders).

RESULTS

In all, 131 PDMS-U and 153 MUS surgery patients were treated. Subjective cure rates for MUS surgery and PDMS-U were, respectively: 101/112 (90%) versus 40/87 (46%), adjusted odds ratio (aOR; for age, body mass index [BMI], severity, type of urinary incontinence and previous SUI procedure) was 4.9. Objective cure rates for MUS surgery and PDMS-U were respectively: 98/109 (90%) versus 58/92 (63%), aOR 5.4. Average total costs for PDMS-U and MUS surgery were €3567 and €6688. ICER for MUS surgery cost €15 598 per IIQ QALY and €37 408 per EQ-5D-5L QALY. With a willingness to pay (WTP) of €25 000, MUS has a 84% chance of being cost-effective using IIQ, whereas PDMS-U has a 99% chance of being cost-effective using EQ-5D-5L.

CONCLUSION

MUS surgery is more cost-effective in realising improved disease-specific quality of life (QoL), while PDMS-U is more cost-effective in realising improved generic QoL.

Physicians’ perspectives on using a patient decision aid in female stress urinary incontinence

Introduction and hypothesis

A treatment choice for female stress urinary incontinence (SUI) is preference sensitive for both patients and physicians. Multiple treatment options are available, with none being superior to any other. The decision-making process can be supported by a patient decision aid (PDA). We aimed to assess physicians’ perceptions concerning the use of a PDA.

Methods

In a mixed methods study, urologists, gynecologists and general practitioners in the Netherlands were asked to fill out a web-based questionnaire. Questions were based on the Tailored Implementation for Chronic Diseases checklist using the following domains: guideline factors, individual health professional factors, professional interactions, incentives and resources, and capacity for organizational change. Participants were asked to grade statements using a five-point Likert scale and to answer open questions on facilitators of and barriers to implementation of a PDA. Outcomes of statement rating were quantitatively analyzed and thematic analysis was performed on the outcomes regarding facilitators and barriers.

Results

The response rate was 11%, with a total of 120 participants completing the questionnaire. Ninety-two of the physicians (77%) would use a PDA in female SUI. Evidence-based and unbiased content, the ability to support shared decision making, and patient empowerment are identified as main facilitators. Barriers are the expected prolonged time investment and the possible difficulty using the PDA in less health-literate patient populations.

Conclusions

The majority of physicians would use a PDA for female SUI. We identified facilitators and barriers that can be used when developing and implementing such a PDA.

Pain after midurethral sling; the underestimated role of mesh removal

Introduction

The primary aim of this study was to evaluate the results of midurethral sling (MUS) removal in women who have pain as their single complication of MUS.

Material and methods

We performed a retrospective chart study supplemented with a cross sectional questionnaire. Women who underwent MUS removal for pain as the solitary reason for removal between 2004 and 2018 were included. Primary outcome was change in pain levels assessed by the visual analogue scale (VAS) pain score (range 0–10). Secondary outcome was the recurrence of stress urinary incontinence (SUI).

Results

Twenty-six of 31 patients returned the questionnaire. Median medical file follow-up was 12 months (range 2–66) and 25 months (range 5–104) regarding questionnaires. VAS pain score dropped from 7.8 (SD 1.9) at baseline to 4.5 (SD 3.2) at follow-up (p <.00). Seven (23%) patients were pain-free. Patients undergoing partial vaginal resection (n = 6) had a VAS pain score decrease of 4.7 (p = .02) versus 2.7 (p = .02) for complete vaginal removal (n = 14). Twenty-three (89%) patients experienced SUI at follow-up, whereof 10 (45%) reported (almost) no incidents of SUI.

Conclusions

MUS removal is a viable and safe option with a significant drop in VAS pain score in patients with chronic pain after MUS placement. A post-operative increase of SUI and a possible renewed wish for SUI treatment have to be considered. This should not be a reason to refrain from information and/or referral for surgical removal.

Urodynamic effects of prostatic urethral lift procedure for male voiding LUTS

AIMS

Primary objective is to investigate whether prostatic urethral lift (PUL) results in an improvement of urodynamic parameters that define bladder outlet obstruction (urethral resistance algorithm [URA], Schäfer grade, PdetQmax, PdetOpen).

METHODS

20 patients (main inclusion criteria: ≥ 50 years of age, BPO, IPSS ≥ 13, prostate volume ≤ 60 mL, no middle prostate lobe) were enrolled in the study and a PUL was performed. Patients underwent urodynamic investigation and filled out the IPSS and QoL before and after PUL. A paired T test was used to analyze the results.

RESULTS

The mean age was 68 years (range 55-79), mean prostate volume (TRUS) was 45 mL (range 20-59) and mean PSA was 2.0 ug/L (0.2-4.4). IPSS of the 16 patients reduced significantly (from 22.20 to 14.47, p=0.000). Qmax during pressure flow study improved significantly (from 4.5 ml/s to 7.2 ml/s, p=0.001), no significant difference was found in Qmax during free uroflowmetry. There was no significant difference found in post voiding residual. URA decreased significantly post treatment (from 52 cmH2O to 37 cmH2O, p=0.000). The Schäfer obstruction plot decreased significantly (from 3.5 to 2.6, p= 0.022). Seven patients underwent Greenlight Laser Vaporization of the prostate after the PUL due to unsatisfactory results.

CONCLUSIONS

PUL has desobstructive effects, but they seem clinically modest. The procedure improves urodynamic parameters as well as QoL in males with LUTS based on BPO. However, the mechanism how PUL leads to a remarkable symptom relieve remains unclear and cannot be explained by the desobstructive mechanisms we observed.

Genetic variants and expression changes in urgency urinary incontinence: A systematic review

Aim

To perform a systematic review summarizing the knowledge of genetic variants, gene, and protein expression changes in humans and animals associated with urgency urinary incontinence (UUI) and to provide an overview of the known molecular mechanisms related to UUI.

Methods

A systematic search was performed on March 2, 2020, in PubMed, Embase, Web of Science, and the Cochrane library. Retrieved studies were screened for eligibility. The risk of bias was assessed using the ROBINS‐I (human) and SYRCLE (animal) tool. Data were presented in a structured manner and in the case of greater than five studies on a homogeneous outcome, a meta‐analysis was performed.

Results

Altogether, a total of 10,785 records were screened of which 37 studies met the inclusion criteria. Notably, 24/37 studies scored medium‐high to high on risk of bias, affecting the value of the included studies. The analysis of 70 unique genes and proteins and three genome‐wide association studies showed that specific signal transduction pathways and inflammation are associated with UUI. A meta‐analysis on the predictive value of urinary nerve growth factor (NGF) levels showed that increased urinary NGF levels correlate with UUI.

Conclusion

The collective evidence showed the involvement of two molecular mechanisms (signal transduction and inflammation) and NGF in UUI, enhancing our understanding of the pathophysiology of UUI. Unfortunately, the risk of bias was medium‐high to high for most studies and the value of many observations remains unclear. Future studies should focus on elucidating how deficits in the two identified molecular mechanisms contribute to UUI and should avoid bias.

Long-term real-life adherence of percutaneous tibial nerve stimulation in over 400 patients

Background

Percutaneous tibial nerve stimulation (PTNS) is used as a treatment to reduce the complaints of overactive bladder (OAB). Although it is rewarding therapy patients need maintenance treatment to preserve the beneficial effect.

Aim

This real‐life retrospective study was performed to assess the feasibility of PTNS adherence.

Materials & methods

All patients who underwent PTNS were retrospectively included. We analyzed the following: indication, kind of treatments (pharmacologic and third‐line therapy) before and after PTNS treatment, time and reason for quitting therapy. Statistical analysis was done by performing competitive‐risk analysis and Kaplan‐Meier curves. Patients were categorized into four groups. Group 1: all patients; group 2: all patients on maintenance PTNS therapy (continuing after 12 weeks); group 3: patients on maintenance PTNS therapy excluding the following: (a) patients with initial good response who seized treatment due to death, (b) patient who successfully switched to transcutaneous stimulation, (c) patients who were cured of their OAB symptoms, or (d) patients who relocated; and group 4: group 3 but excluding those who stopped treatment because of nonmedical reasons (physical strain, inconveniencies associated with visiting the hospital).

Results

Four‐hundred two patients (70% female) with a median age of 70 years underwent PTNS. Underlying treatment indications were: OAB‐wet (54%) and OAB‐dry (29%). The median follow‐up (FU) of group 1 was 4 months. Fifty‐seven percent (N = 228) of the patients received maintenance PTNS therapy. Median FU in group 4 was 46 months (range, 3‐111 months). Over 40% of the maintenance patients stopped PTNS because of logistic reasons and physical strain during an FU time of 6 years.

Conclusion

The real‐world data described here with is in line with earlier published work in terms of the success rate of OAB treatment. However, over 40% quit their therapy due to nonmedical reasons.

Improving the barrier function of damaged cultured urothelium using chondroitin sulfate

AIMS

To determine whether glycosaminoglycan (GAG) replenishment is able to improve recovery of a deficient urothelial barrier, chondroitin sulfate (CS) instillations were tested using an in vitro model. Porcine urothelial cells (Ucells) were terminally differentiated in culture conditions to construct a urothelial layer with a functional barrier. This layer was damaged to compromise barrier function to simulate a key characteristic of bladder pain syndrome/interstitial cystitis. The functional effect of subsequent treatment with CS was evaluated.

METHODS

Primary porcine Ucells were isolated and cultured on inserts. Differentiation of cells was evaluated with immunohistochemical analysis for the presence of umbrella cells, tight junctions and CS. Transepithelial electrical resistance (TEER) measurements were performed to evaluate barrier function. Protamine was used to simulate mild urothelial damage. CS 0.2% (vol/vol), a GAG, was subsequently instilled in the treatment group. The recovery of barrier function was further evaluated with TEER measurements. The Student t test was used for the analysis of results.

RESULTS

After induction of differentiation, the Ucells expressed barrier markers and a functional barrier was established (measured by high TEER). TEER decreased significantly after instillation with protamine. CS instillation improved recovery of TEER significantly measured after 7 hours (84% vs 22% in controls). After 24 hours; however, the TEER was comparable in both experimental groups.

CONCLUSION

CS instillation improves the recovery of the urothelial barrier after damage in vitro. This functional experiment shows that CS improves recovery of damaged urothelial function, which supports the hypothesis behind the mechanism of action of GAG-replenishment therapy.

De-implementation of urodynamics in The Netherlands after the VALUE/VUSIS-2 results: a nationwide survey

INTRODUCTION AND HYPOTHESIS

We aimed to estimate the level of de-implementation of preoperative routine urodynamics (UDS) before stress urinary incontinence (SUI) surgery in The Netherlands and to analyze facilitators and barriers. Routine UDS was performed by 37% of the medical specialists in 2010. We hypothesized that the recommendations from the recent Value of Urodynamics prior to Stress Incontinence Surgery (VUSIS) and Value of Urodynamic Evaluation (ValUE) studies would have been followed by a reduction of routine UDS.

METHODS

A national survey was performed among all Dutch gynecologists and urologists dealing with SUI in daily practice. The questionnaire contained two parts: (1) respondents' characteristics and their actual care concerning preoperative UDS, and (2) facilitators and barriers.

RESULTS

The response rate was 41% (127/308). Of the respondents, 93% (n = 118) did not perform routine UDS in the preoperative workup for women in this group. Professional characteristics associated with not following the recommendations were profession urologist, academic hospital, and a lower number of midurethral sling (MUS) placed yearly. Facilitators to follow the recommendation not to perform routine UDS were adequate design of the VUSIS-II study and outcome and recommendations from the studies. Barriers not to follow the recommendation were believe in the additional value of UDS, especially the pressure transmission ratio, and the presence of detrusor overactivity.

CONCLUSION

According to respondents to this questionnaire, VUSIS-II and ValUE study results are well implemented in The Netherlands. The vast majority of respondents replied as not performing routine preoperative UDS in women with primary, uncomplicated (predominant) SUI. Therefore, there is no need for a further de-implementation strategy.

[Severe vaginal discharge following rectal surgery]

BACKGROUND

Almost 50% of women who have had rectal surgery subsequently develop vaginal discharge. Due to the recurrent and unexpected nature of this heavy discharge, they often experience it as very distressing. Many of these women undergo extensive diagnostic tests that are mainly focused on identifying fistula formation. If no fistula is found, in most cases no other cause for severe vaginal discharge can be demonstrated.

CASE DESCRIPTION

In our practice, we saw three patients (49-, 54- and 74-years-old, respectively) with similar severe vaginal discharge after rectal surgery and in whom no explanation for the vaginal discharge could be found. For this reason we conducted a literature search into this condition.

CONCLUSION

Anatomical changes appear to be responsible for heavy vaginal discharge following rectal surgery. Changes in pelvic floor muscles and compression of the distal part of the vagina may lead to pooling of fluid in the proximal part of the vagina, resulting in severe discharge. Symptomatic treatment may reduce the symptoms.

A novel leadless, miniature implantable Tibial Nerve Neuromodulation System for the management of overactive bladder complaints

BACKGROUND

Overactive bladder is a chronic condition affecting lower urinary tract function that has a significant negative impact on QoL.

OBJECTIVE

Evaluation of the BlueWind implantable tibial nerve system performance and safety in refractory OAB.

DESIGN, SETTING, AND PARTICIPANTS INTERVENTION

A 6-month multi-center prospective intervention study.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Objective assessment was done by voiding diary parameters including voids/day, volume voided/day, urgency assessment, leaking episodes/day, pads used/day, leak severity, and clinical success defined as a ≥50% reduction in the number of leaks/day or number of voids/day or number of episodes with degree of urgency >2 or a return to <8 voids/day on a 3 Day diary. Subjective assessment was based on OAB-q including HRQL and symptom severity score. Safety was evaluated by adverse event (AE) analysis.

RESULTS AND LIMITATIONS

Thirty-four of the 36 implanted subjects completed the study. One subject withdrew voluntarily and one developed inflammation necessitating removal of the system. In the remaining subjects, 71% experienced clinical success at 6 months. Leaks/day, leak severity, and pad changes/day decreased significantly over time with 27.6% of urge incontinence subjects that became "dry." Voids/day, degree of urgency, volume/void, pads changed improved significantly. All quality of life aspects (concern, coping, sleep, and social) improved as well as symptom severity scores measured by the OAB-q. Adverse events included: implant site pain (13.9%), suspected infection (22.2%), and procedural wound complications (8.3%).

CONCLUSIONS

The BlueWind implantable tibial nerve stimulator is a safe, minimally invasive system that affords OAB patients significant improvements.

PATIENT SUMMARY

The performance and safety of the BlueWind RENOVA™ implantable tibial nerve neuromodulator for OAB was tested. Our preliminary results demonstrate that the system has a low risk safety profile and may be considered an effective treatment option for OAB management.

A New Implanted Posterior Tibial Nerve Stimulator for the Treatment of Overactive Bladder Syndrome: 3-Month Results of a Novel Therapy at a Single Center

PURPOSE

This study was designed to investigate the safety and performance of a new implantable system for tibial nerve stimulation for overactive bladder symptoms.

MATERIALS AND METHODS

A battery-free stimulation device for tibial nerve stimulation (BlueWind Medical, Herzliya, Israel) was implanted in 15 patients. Safety and efficacy assessments were done at 3 months after activation with a 3-day bladder diary, a 24-hour pad test and 2 quality of life questionnaires.

RESULTS

Two males and 13 females were enrolled in the study. Mean age was 54 years (range 19 to 72). Five of 15 patients were previously treated with percutaneous tibial nerve stimulation and 12 experienced urgency urinary incontinence. Median operative time was 34 minutes. At 3 months of followup a significant change was seen in 24-hour frequency from a mean ± SD of 11.8 ± 3.5 to 8.1 ± 2.0 times per day (p = 0.002), the number of severe urinary urgency episodes from 6.5 ± 5.1 to 2.0 ± 2.1 times per day (p = 0.002), the number of severe incontinence episodes from 2.8 ± 5.2 to 0.3 ± 0.4 episodes per day (p = 0.017), urinary loss per day from 243 ± 388 to 39 ± 55 gm (p = 0.038) and improvement in quality of life. After implantation, 3 patients received prolonged antibiotic treatment and 3 received pain medication for 1 week. In 1 patient the device was explanted due to pain and swelling suspicious for infection, although tissue cultures did not reveal a bacterial infection.

CONCLUSIONS

This novel posterior tibial nerve stimulator is safe and easy to implant with good clinical results.

Para-Urethral Injections with Urolastic® for Treatment of Female Stress Urinary Incontinence: Subjective Improvement and Safety

INTRODUCTION

Female stress urinary incontinence (SUI) is often treated surgically. Urethral bulking agents are a minimally invasive alternative, especially in patients suffering from intrinsic sphincter deficiency, but often with limited long-term efficacy. Urolastic® is a non-deformable, non-resorbable silicone elastomer that is used as an injectable. Its properties might result in a more durable response after injection. If this durability factor can be combined with a low complication rate, this can become a useful treatment option. We therefore assessed the subjective improvement and safety after treatment with Urolastic®.

MATERIALS AND METHODS

In 2 Dutch hospitals, 65 patients were treated with Urolastic®. The subjective improvement was assessed and the medical charts were reviewed for complications that appeared during the follow-up period. The complications were classified using the Clavien-Dindo classification.

RESULTS

We found that 76-88% of the patients showed subjective improvement at 12-25 months follow-up. The rate of improvement experienced was 50-70%. The rate of complications classified as Clavien-Dindo >II was 24-33%. The 12 patients with 75-100% subjective improvement after 2 months, showed 85% improvement after a median of 25 months.

CONCLUSIONS

With careful patient selection, Urolastic® seems to be a safe, durable and effective treatment option for female SUI.

Subject-Controlled, On-demand, Dorsal Genital Nerve Stimulation to Treat Urgency Urinary Incontinence; a Pilot

OBJECTIVES

To evaluate the effect of subject-controlled, on-demand, dorsal genital nerve (DGN) stimulation on non-neurogenic urgency urinary incontinence (UUI) in a domestic setting.

MATERIALS AND METHODS

Non-neurogenic patients >18 years with overactive bladder symptoms and UUI were included. Exclusion criteria were mainly stress urinary incontinence. Patients underwent 1 week of subject-controlled, on-demand, DGN stimulation, delivered by a percutaneously placed electrode near the DGN connected to an external stimulator (pulse-rate 20 Hz, pulse-width 300 μs). Patients activated the stimulator when feeling the urge to void and stimulated for 30 s. The amplitude was set at the highest tolerable level. A bladder diary including a severity score of the UUI episodes/void (scores: 0 = none, 1 = drops, 2 = dashes, 3 = soaks) and a padtest was kept 3 days prior to, during, and 3 days after the test period. The subjective improvement was also scored.

RESULTS

Seven patients (4 males/3 females) were enrolled, the mean age was 55 years (range 23-73). Six completed the test week. In the remaining patient the electrode migrated and was removed. 5/6 finalized the complete bladder diary, 1/6 recorded only the heavy incontinence episodes (score = 3). 4/6 completed the padtest. In all patients who finalized the bladder diary the number of UUI episodes decreased, in 3/5 with ≥60%. The heavy incontinence episodes (score = 3) were resolved in 2/6 patients, and improved ≥80% in the other 4. The severity score of the UUI episodes/void was improved with ≥ 60% in 3/5 patients. The mean subjective improvement was 73%.

CONCLUSION

This feasibility study indicates that subject-controlled, on-demand DGN stimulation using a percutaneously placed electrode is possible over a longer time period, in a home setting, with a positive effect on non-neurogenic overactive bladder symptoms with UUI. Although the placement is an easy procedure, it is difficult to fixate the electrode to keep it in the correct position. Improvements in hardware, like a better fixated electrode and an easy to control stimulator, are necessary to make SODGNS a treatment possibility in the future.

Botulinum Toxin A in Clinical Practice, the Technical Aspects and What Urologists Want to Know about It

OBJECTIVES

To give an overview of the literature concerning the clinical practice of Botulinum toxin A (BTA) treatment to meet the needs and knowledge of urologists.

METHODS

A literature search was performed to BTA treatment, together with a survey among Dutch urologist.

RESULTS

The registration trials used strict inclusion and exclusion criteria, a standardized application technique and follow-up. The approval for BTA is based on these trials but differs from country to country. BTA was already used before these approvals, with different application techniques. Published manuscripts about application techniques (trigone sparing/suburothelial injections/intradetrusor injections) show different outcomes. In literature there is no positive or negative predictor found with a preoperatively urodynamic investigation. It is shown that retreatment does not cause inflammatory infiltration or fibrosis in the bladder wall. The survey showed that in 96% of the urology departments BTA is used. Urodynamic investigation is requested by 87% of urologists before the treatment. Although it is regarded as an easy-to-learn procedure 60% of urologists would like training in practical aspects.

CONCLUSIONS

No firm data exist about the technique of application with consequently the most optimal results. BTA treatment is regarded as an easy-to-learn, but still there is a request for training in practical treatment aspects.

Results of primary versus recurrent surgery to treat stress urinary incontinence in women

Introduction and hypothesis

We compared cure rates and complication rates in patients who had undergone primary or recurrent (secondary) surgery for stress urinary incontinence (SUI).

Methods

A retrospective cohort study that included patients who underwent surgery to treat SUI in a tertiary referral center was carried out. All patients had, predominantly, SUI. Exclusion criteria were patients with a neurogenic bladder or a neobladder and patients without postoperative follow-up (FU). The primary objective was to assess the success rate, defined as cured SUI or improved SUI at six weeks and at the latest available moment of FU. The secondary objective was to assess complications.

Results

A total of 541 women with SUI underwent surgery for SUI between 2002 and 2010. After exclusion of 102 patients a total of 242 patients with primary SUI and 197 patients with recurrent SUI were identified. The success rate at first FU was 89 %. At last FU (median 205 days) the success rate was 83 % (P < 0.01). There were no significant differences in success rate between primary and recurrent surgery at first FU. The overall success rate of primary surgery was 86 %; for recurrent surgery it was 79 %. During surgery, 27 bladder injuries occurred (6.2 %), with no significant difference between the two groups. At last FU, 11 patients (2.6 %) had persistent residual volume, necessitating prolonged clean intermittent self-catheterization.

Conclusions

The results of recurrent surgery to treat recurrent or persistent SUI are still good in experienced hands and do not significantly differ from results of primary surgery. The complication rates are comparable to those of primary surgery.

Implant-Driven Tibial Nerve Stimulation in the Treatment of Refractory Overactive Bladder Syndrome: 12-Month Follow-up

Objectives.  To investigate feasibility and safety of implant-driven tibial nerve stimulation. Materials and Methods.  Eight patients with refractory overactive bladder were successfully treated with implanted percutaneous tibial nerve stimulation (PTNS). Patients were evaluated with bladder diaries, quality of life questionnaires, and physical examination before implantation, and at 3, 6, and 12 months of follow-up. The primary objective was ≥ 50% reduction of the number of incontinence episodes and/or voids on bladder diary. The Wilcoxon signed ranks test was used. Results.  At 3, 6 and 12 months, respectively five, six, and four patients met the primary objective. At 3- and 6-month follow-up, voiding and quality of life parameters had significantly (p < 0.05) improved. Urinary tract infection, temporarily walking difficulties, and spontaneous radiating sensations were reported as adverse events and no local infection, erosion, or dislocation. Conclusions.  Implant-driven tibial nerve stimulation seems to be feasible and safe.

Can preoperative urodynamic investigation be omitted in women with stress urinary incontinence? A non-inferiority randomized controlled trial

AIMS

To assess in women with stress urinary incontinence (SUI) the value of urodynamics prior to treatment.

METHODS

We performed a multicenter non-inferiority randomized controlled trial. Women with SUI were randomly allocated to management based on a workup with or without urodynamics. The primary outcome was clinical reduction of complaints as measured with the Urogenital Distress Inventory urinary incontinence subscale (UDI-UI) at 12 months after the onset of treatment. A mean difference in improvement of less than 8 was considered non-inferior. The study was analyzed according to intention-to-treat.

RESULTS

The trial was stopped prematurely because of slow recruitment. We randomly allocated 59 women to a strategy with (N = 31) or without (N = 28) urodynamics. The mean difference in improvement on the UDI-UI was 14 in favor of the group without urodynamics (48 SD ± 22 vs. 34 SD ± 22, 95% CI: -28 to -0.26), confirming non-inferiority. Addition of urodynamics did not result in a lower occurrence of de novo overactive bladder complaints compared to a workup without urodynamics (6/31 vs. 1/28; RR 5.4, 95% CI: 0.70-42). In the group allocated to urodynamics, initial surgical management was more often abandoned compared to the group not allocated to urodynamics (5/31 vs. 1/28; RR 4.5, 95% CI: 0.56-36).

CONCLUSIONS

In this relatively small study, the omission of urodynamics was not inferior to the use of urodynamics in the preoperative workup of women with SUI. Women with SUI undergoing urodynamics had the risk of a choice for more prudent treatment, which seemed to result in a delay until effective treatment.

The value of preoperative urodynamics according to gynecologists and urologists with special interest in stress urinary incontinence

INTRODUCTION AND HYPOTHESIS

The aim of this study is to assess variations in practice in the use of preoperative urodynamics in women with stress urinary incontinence (SUI).

METHODS

We performed an E-survey among all Dutch gynecologists and urologists who have SUI as focus in daily practice. The questions concerned the common policy and preferred policy. Descriptive statistics were used.

RESULTS

Of the 260 targeted specialists, 163 (63%) responded. We found that 37% of the respondents performed standard preoperative urodynamics; in the preferred practice, this would reduce to only 18%. Eighty percent indicated they would operate a patient with a positive stress test without urodynamic SUI, whereas 21% would do this also in case the clinical stress test was negative. Only 9% of the respondents indicated they adapted the choice of the type of sling based on urethral pressure profilometry parameters.

CONCLUSIONS

Urodynamics are not routinely performed, and outcomes hardly influence the choice of treatment.

Failure of posaconazole therapy in a renal transplant patient with invasive aspergillosis due to Aspergillus fumigatus with attenuated susceptibility to posaconazole

We report the case of a kidney transplant recipient with invasive aspergillosis due to Aspergillus fumigatus resistant to voriconazole and intermediately susceptible to posaconazole who failed posaconazole therapy. Plasma posaconazole concentrations indicated an unfavorable ratio of the area under the concentration-time curve over the MIC. Posaconazole should be used with caution for invasive aspergillosis caused by strains with attenuated posaconazole susceptibility, as drug exposure may be inadequate, resulting in therapeutic failure.

No primary role of ambulatory urodynamics for the management of spinal cord injury patients compared to conventional urodynamics

AIMS

Adequate urodynamic assessment of bladder behavior is essential in spinal cord injury (SCI) patients. Ambulatory urodynamics are more sensitive to detect detrusor overactivity (DO) than conventional urodynamics. The primary objective of this study was to determine the value of ambulatory urodynamics for the diagnosis of DO in SCI patients compared to conventional urodynamics.

METHODS

Twenty-seven SCI patients who were suspected of DO underwent both conventional and ambulatory urodynamics at one day. A single involuntary detrusor contraction (IDC) was defined as a detrusor pressure rise of at least 10 cmH(2)O. DO according to the ICS definition was used in addition to minimize the influence of catheter artifacts. Outcome of urodynamics was used for decisions on treatment.

RESULTS

Ambulatory urodynamics were more sensitive to diagnose IDC and DO. Conventional urodynamics had a sensitivity of 82% and specificity of 75% for DO diagnosis compared to ambulatory urodynamics. Mean maximum detrusor pressures did not differ significantly between both urodynamics. When the maximum detrusor pressure at conventional urodynamics did not exceed 40 cmH(2)O, 83% (10/12) of patients had a mean maximum detrusor pressure under 40 cmH(2)O at ambulatory urodynamics. Although the inter-individual DO diagnostic agreement was lower for ambulatory than conventional urodynamics (58%, K = 0.201 vs. 77%, K = 0552), the treatment agreement was higher for ambulatory urodynamics (58% vs. 42%).

CONCLUSIONS

Ambulatory urodynamics do not seem necessary for diagnosis and risk assessment in SCI patients suspected for DO when conventional urodynamics are done properly. The exact role of urodynamics in treatment decision remains to be determined.

The correlation between clinical and urodynamic diagnosis in classifying the type of urinary incontinence in women. A systematic review of the literature

AIMS

To determine the reclassification rate of clinically diagnosed stress, mixed, and urge urinary incontinence after urodynamic investigation.

METHODS

A systematic review of the published literature in MEDLINE and EMBASE of clinical trials among women with urinary incontinence. Studies were included in case the diagnosis based on symptoms and/or signs was compared with the diagnosis after urodynamic investigation.

RESULTS

Twenty-three articles involving 6,282 women with urinary incontinence met the inclusion criteria. A clinical diagnosis of stress urinary incontinence was reclassified into mixed urinary incontinence in 9% of women and into detrusor overactivity (DO) in 7% of cases. The pooled reclassification rate was highest among patients with symptoms of mixed urinary incontinence, where 46% of the patients had stress urinary incontinence and 21% had DO on urodynamic investigation. The available literature does not allow the identification of the additional value of non-invasive test, such as stress test and voiding diary, accessory to symptoms. None of the studies had therapeutic effects as an outcome measure.

CONCLUSIONS

This review of clinical studies shows that the level of agreement between classification based on clinical evaluation and based on urodynamic investigation is poor. Urodynamic observations are regarded as gold standard, but based on the poor correlation, this assumption should be questioned.

Minimal invasive electrode implantation for conditional stimulation of the dorsal genital nerve in neurogenic detrusor overactivity

STUDY DESIGN

Experimental.

OBJECTIVES

Electrical stimulation of the dorsal genital nerves (DGN) suppresses involuntary detrusor contractions (IDCs) in patients with neurogenic detrusor overactivity (DO). The feasibility of minimal invasive electrode implantation near the DGN and the effectiveness of conditional stimulation to suppress IDCs at different amplitudes in spinal cord injury (SCI) patients with DO were studied.

SETTING

Radboud University Nijmegen MC, The Netherlands.

METHODS

In eight healthy volunteers, a needle electrode was inserted from both a medial and lateral-to-midline site at the level of the pubic bone. Electrode insertion was guided by the genito-anal reflex (GAR) evoked by electrical stimulation and by sensation to this stimulation. In eight SCI patients with DO, the bladder was repeatedly filled and emptied partially in between. Conditional stimulation using a needle electrode was applied when an IDC was observed at urodynamics. Different amplitudes were used during each filling. Control cystometry was carried out before electrode insertion and after stimulation.

RESULTS

The lateral implant approach was preferred, as it was easier to manoeuvre the needle along the pubic bone and fixate the needle. In SCI patients, the electrode was positioned successfully, and IDCs were suppressed (range 1-6 IDC suppressions) with conditional stimulation at maximum tolerable amplitude, except for one patient. Stimulation was less effective at lower amplitudes. Stimulation lowered the intensity of bladder sensations concomitant with IDC.

CONCLUSION

The lateral-to-midline implant approach, in combination with GAR and sensation to stimulation, is feasible for electrode implantation near the DGN in SCI patients. Conditional stimulation effectively suppresses IDCs.

Urethral instability: current pathophysiological concept

The role of urethral pressure variations during filling cystometry is seldom assessed as a potential cause of voiding dysfunction and/or storage disorders. In this article, we review current research in the field of urethral pressure variations and discuss the way of determining urethral pressure variations, its value for the clinical practice and hypothesize the origin of urethral pressure variations. The observation and recognition of urethral pressure variations (urethral instability) could be valuable in the diagnosis and evaluation of therapy in functional lower urinary tract disorders.

Limited value of bladder sensation as a trigger for conditional neurostimulation in spinal cord injury patients

AIMS

Conditional stimulation of dorsal genital nerves suppresses undesired detrusor contractions (UDC) and consequently increases bladder capacity and prevents incontinence. No clinically applicable sensor exists for reliable bladder activity monitoring as a trigger for conditional stimulation. Primary objective of this study was to determine whether bladder sensation concomitant with UDC may be used for spinal cord injury (SCI) patients to trigger neurostimulation in daily life.

METHODS

Nineteen male and 7 female SCI patients suspected of detrusor overactivity (DO) underwent conventional and 6-hr ambulatory urodynamics. Patients were instructed to do normal daily activities and to activate event buttons of the ambulatory recorder to mark events: physical activity, bladder sensation, micturition or intermittent catheterization, and urinary incontinence. Detection rate was defined as the number of recorded bladder sensation divided by the total number of recorded UDC during ambulatory urodynamics.

RESULTS

Bladder sensation was reported by 73% of patients in daily life. Only 41% of patients had analyzable bladder sensation concomitant with UDC during ambulatory urodynamics. For ambulatory and conventional urodynamics, mean detection rates were 23% and 72%, respectively, with mean recording delays of 57 and 16 sec after UDC onset, respectively.

CONCLUSIONS

Bladder sensation only occurs in a small group of SCI patients combined with a rather low detection rate and long reaction time. Therefore, bladder sensation as a trigger for conditional stimulation does not seem to be suitable for SCI patients with DO. Reliable techniques for chronic bladder activity monitoring are a prerequisite for successful clinical application of conditional stimulation.

Protocol for the value of urodynamics prior to stress incontinence surgery (VUSIS) study: a multicenter randomized controlled trial to assess the cost effectiveness of urodynamics in women with symptoms of stress urinary incontinence in whom surgical treatment is considered

Background

Stress urinary incontinence (SUI) is a common problem. In the Netherlands, yearly 64.000 new patients, of whom 96% are women, consult their general practitioner because of urinary incontinence. Approximately 7500 urodynamic evaluations and approximately 5000 operations for SUI are performed every year. In all major national and international guidelines from both gynaecological and urological scientific societies, it is advised to perform urodynamics prior to invasive treatment for SUI, but neither its effectiveness nor its cost-effectiveness has been assessed in a randomized setting.

The Value of Urodynamics prior to Stress Incontinence Surgery (VUSIS) study evaluates the positive and negative effects with regard to outcome, as well as the costs of urodynamics, in women with symptoms of SUI in whom surgical treatment is considered.

Methods/design

A multicentre diagnostic cohort study will be performed with an embedded randomized controlled trial among women presenting with symptoms of (predominant) SUI.

Urinary incontinence has to be demonstrated on clinical examination and/or voiding diary. Physiotherapy must have failed and surgical treatment needs to be under consideration.

Patients will be excluded in case of previous incontinence surgery, in case of pelvic organ prolapse more than 1 centimeter beyond the hymen and/or in case of residual bladder volume of more than 150 milliliter on ultrasound or catheterisation.

Patients with discordant findings between the diagnosis based on urodynamic investigation and the diagnosis based on their history, clinical examination and/or micturition diary will be randomized to operative therapy or individually tailored therapy based on all available information.

Patients will be followed for two years after treatment by their attending urologist or gynaecologist, in combination with the completion of questionnaires.

Six hundred female patients will be recruited for registration from approximately twenty-seven hospitals in the Netherlands. We aspect that one hundred and two women with discordant findings will be randomized.

The primary outcome of this study is clinical improvement of incontinence as measured with the validated Dutch version of the Urinary Distress Inventory (UDI). Secondary outcomes of this study include costs, cure of incontinence as measured by voiding diary parameters, complications related to the intervention, re-interventions, and generic quality of life changes.

Trial registration

Clinical Trials NCT00814749.

[The practice guideline 'Urinary incontinence' (first revision) from the Dutch College of General Practitioners; a response from the perspective of urology]

The revised practice guideline 'Urinary incontinence' of the Dutch College of General Practitioners contains some important changes. Urodynamic investigation is not mandatory for differentiating between types of incontinence in the general practice setting. Physical examination including a valsalva leak point test is considered important. From a urological point ofview it remains to be seen whether the history-taking and the physical examination described in the revised guideline will be enough to accurately differentiate between the possible incontinence types. The practice guideline underlines a role for the general practitioner in teaching bladder training or pelvic floor exercises. The benefits of this compared to exercises taught by specialized physiotherapists will have to be determined. Another new feature is that antimuscarinic drugs are mentioned as proper treatment for people suffering from overactive bladder complaints. The practice guideline advises referral of male incontinence patients only if the incontinence is not related to prostate surgery. However, patients with postoperative incontinence should also be referred as there are good diagnostic and therapeutic options available.

[Male urinary incontinence]

*Urinary incontinence in males is gaining increasingly more attention. *Male urinary incontinence can be classified as storage incontinence due to overactive bladder syndrome or stress incontinence due to urethral sphincter dysfunction. *Most patients benefit from the currently available treatment options for overactive bladder, which include physiotherapy, medication, botulinum A toxin injections and neuromodulation techniques. *The number of radical prostatectomies performed for prostate cancer is increasing; this intervention can lead to stress incontinence due to sphincter weakness. *Various treatment options are available for stress incontinence due to sphincter weakness. *In addition to physiotherapy, treatment options also include the artificial urinary sphincter, which has been available for decades. *New treatments include para-urethral balloons and male slings. The value of these approaches must be proven in the coming years.

Results of sacral neuromodulation therapy for urinary voiding dysfunction: outcomes of a prospective, worldwide clinical study

PURPOSE

This 5-year, prospective, multicenter trial evaluated the long-term safety and efficacy of sacral neuromodulation in patients with refractory urge incontinence, urgency frequency and retention.

MATERIALS AND METHODS

A total of 17 centers worldwide enrolled 163 patients (87% female). Following test stimulation 11 patients declined implantation and 152 underwent implantation using InterStim. Of those treated with implantation 96 (63.2%) had urge incontinence, 25 (16.4%) had urgency frequency and 31 (20.4%) had retention. Voiding diaries were collected annually for 5 years. Clinical success was defined as 50% or greater improvement from baseline in primary voiding diary variable(s).

RESULTS

Data for all implanted cases were reported. For patients with urge incontinence mean leaking episodes per day decreased from 9.6 +/- 6.0 to 3.9 +/- 4.0 at 5 years. For patients with urgency frequency mean voids per day decreased from 19.3 +/- 7.0 to 14.8 +/- 7.6, and mean volume voided per void increased from 92.3 +/- 52.8 to 165.2 +/- 147.7 ml. For patients with retention the mean volume per catheterization decreased from 379.9 +/- 183.8 to 109.2 +/- 184.3 ml, and the mean number of catheterizations decreased from 5.3 +/- 2.8 to 1.9 +/- 2.8. All changes were statistically significant (p <0.001). No life threatening or irreversible adverse events occurred. In 102 patients 279 device or therapy related adverse events were observed. At 5 years after implantation 68% of patients with urge incontinence, 56% with urgency frequency and 71% with retention had successful outcomes.

CONCLUSIONS

This long-term study demonstrates that InterStim therapy is safe and effective for restoring voiding in appropriately selected cases refractory to other forms of treatment.

[Some complications of tension-free midurethral tapes for the treatment of stress incontinence in women]

Complications occurred in two women of 45 and 54 years of age who were treated with tension-free midurethral sling procedures. The first woman was treated with transobturator tape due to stress incontinence and an overactive bladder. The procedure resulted in a worsening of the overactive bladder. The second woman was treated with tension-free vaginal tape (TVT) due to stress incontinence and subsequently suffered from pain on urinating. In the first patient, the tape was found to be too tight and following adjustment of the tape tension, the overactive bladder symptoms and the stress incontinence disappeared. The second woman experienced bladder erosion on the right side. After removal of the tape, the symptoms disappeared but the stress incontinence returned. During the last few years, the surgical treatment of stress urinary incontinence has shifted towards the positioning of tension-free tapes. Because this minimally invasive technique is fairly simple to perform, the number of anti-incontinence surgical procedures has increased threefold in the last 4 years in the Netherlands. The literature states high success rates and low complication percentages. However, in everyday practice, these results cannot always be achieved. Doctors should therefore show caution when selecting patients for tension-free midurethral tape procedures. Furthermore, patient information should clearly indicate the actual results. Initial treatment for stress incontinence should consist of intensive pelvic floor muscle training.

Urethral instability and sacral nerve stimulation-a better parameter to predict efficacy?

PURPOSE

Urodynamic parameters that predict the outcome of sacral nerve stimulation are difficult to define. We studied the predictive value of urethral instability and other urodynamic parameters on the efficacy of sacral nerve stimulation.

MATERIALS AND METHODS

Patients with refractory voiding disorders were implanted with a neurostimulator after responding with more than 50% improvement in main symptoms after percutaneous nerve evaluation. Filling cystometry was performed with 3 urethral sensors and 1 bladder sensor at baseline and 6 months after implantation. Urethral pressure variations more than 15 cm H(2)O were considered pathological and defined as urethral instability. Clinical efficacy was evaluated by voiding diary data and defined as successful when greater than 50% improvement was observed.

RESULTS

A total of 19 female patients enrolled in the study. At baseline detrusor overactivity was observed in 9 patients, while 18 showed urethral instability. Sacral nerve stimulation therapy was successful in 13 patients (68%). The number of pads used per day and the severity of leakage decreased significantly. Of the 13 successfully treated patients 12 showed urethral instability at baseline. Detrusor overactivity was present in 4 successfully treated patients. Urethral instability disappeared in 7 of the 13 successfully treated patients and detrusor overactivity disappeared in only 1 of these patients.

CONCLUSIONS

In this study urethral instability appeared to be a valuable urodynamic parameter for predicting the outcome of sacral nerve stimulation.

Cadherin-11 is expressed in detrusor smooth muscle cells and myofibroblasts of normal human bladder

OBJECTIVES

It has recently been found that detrusor smooth muscle cells and myofibroblasts are coupled via gap junctions. However, gap junctions cannot account for strong physical interaction between cells, which has prompted the search for intercellular adhesion molecules. Cadherin-11 is a candidate for such a molecule, since it mediates the interaction of dermal myofibroblasts in contractile wound granulation tissue. We therefore hypothesised that the physical adhesion between detrusor smooth muscle cells and myofibroblasts is mediated by cadherin-11. The aim of this study was to test this hypothesis.

METHODS

Bladder biopsies from eight radical cystectomy specimens were snap-frozen, sectioned, and stained for E-cadherin; cadherin-11; alpha-catenin; beta-catenin; gamma-catenin; and smooth muscle cell/myofibroblast markers connexin-43, vimentin, desmin, smooth muscle actin, and smoothelin. Specimens were analysed by using binocular epifluorescent and confocal laser-scanning microscopy.

RESULTS

Specific positive membranous expression of all adhesion complex molecules except E-cadherin was detected in detrusor suburothelial tissue. All biopsies showed a similar punctate pattern of expression for cadherin-11 within bundles of smooth muscle cells and a suburothelial layer of cells. Cadherin-11 was specifically located at the cell membrane, in distinct linear domains.

CONCLUSIONS

To our knowledge this is the first time evidence has been provided for cadherin-mediated smooth muscle and suburothelial myofibroblast cell-cell interaction in the human bladder. Cadherin-11 most probably plays an important role in the intercellular physical coupling of detrusor smooth muscle cells and also of myofibroblasts.

Current opinion on the working mechanisms of neuromodulation in the treatment of lower urinary tract dysfunction

PURPOSE OF REVIEW

Neuromodulation is a successful treatment for patients with refractory lower urinary tract dysfunction. In the recent years, more applications of various types and ways have been developed and put into clinical practice. It is important, therefore, for urologists to know the existing theories on the working mechanisms that explain the effect. Although much research has been devoted to this subject for the past 35 years, the working mechanism is still unknown. This review presents an overview of the different theories and research into the physiological background of neuromodulation during the past 3 decades with emphasis on recent developments.

RECENT FINDINGS

Specific receptors in the spinal cord have been identified, which are involved in the working mechanism of neuromodulation. The maximal effect of neuromodulation is not directly reached, indicating that neuromodulation induces learning changes (i.e. neural plasticity). The carry-over effect could be caused by negative modulation of excitatory synapses in the central micturition reflex pathway.

SUMMARY

Neuromodulation in the treatment of stress incontinence probably induces physiological changes in the sphincter muscles and pelvic floor. In the treatment of overactive bladder syndrome, nonobstructive voiding dysfunction and chronic pelvic pain, the mechanism of action seems to be more complicated. Most likely, it is a combination of the different suggested modes of action, involving the neuroaxis at different levels.

Percutaneous tibial nerve stimulation in the treatment of refractory overactive bladder syndrome: is maintenance treatment necessary?

OBJECTIVE

To determine the effect of a pause in percutaneous tibial nerve stimulation (PTNS) in successfully treated patients with an overactive bladder (OAB), and the reproducibility of successful treatment when restored.

PATIENTS AND METHODS

Eleven patients (mean age 51 years) with refractory OAB (more than seven voids and/or three or more urge incontinence episodes per day) were successfully treated with PTNS, and then discontinued treatment. Patients completed bladder diaries and quality-of-life (QoL) questionnaires (Short Form-36 and I-QoL) before (T1) and after a 6-week pause (T2) of maintenance PTNS, and again after re-treatment (T3). The first objective was defined as a > or = 50% increase in the incontinence episodes and/or voiding frequency in the bladder diary after T2. The second objective was defined as > or = 50% fewer incontinence episodes and/or voiding frequency in bladder diary after T3.

RESULTS

At T2, seven of the 11 patients had a > or = 50% increase in incontinence episodes and/or voiding frequency in the bladder diary. The mean voided volume, nocturia, number of incontinence episodes and incontinence severity deteriorated significantly (P < 0.05). At T3, nine patients had > or = 50% fewer incontinence episodes and/or voiding frequency in the bladder diary. Nocturia, the number of incontinence episodes, incontinence severity, mean voided volume and quality of life improved significantly (P < 0.05).

CONCLUSIONS

Continuous therapy is necessary in patients with OAB treated successfully by PTNS. The efficacy of PTNS can be reproduced in patients formerly treated successfully.

Correlation between quality of life and voiding variables in patients treated with percutaneous tibial nerve stimulation

OBJECTIVE

To investigate the relationship between quality of life (QoL) and voiding variables in patients with lower urinary tract dysfunction treated with percutaneous tibial nerve stimulation (PTNS), as it is assumed that improvements in voiding will lead to a better QoL in such patients.

PATIENTS AND METHODS

The study included 30 patients with urge urinary incontinence who were treated with PTNS; 24-h bladder diaries and QoL questionnaires (Short Form, SF-36, and incontinence-specific QoL) were completed at baseline and after PTNS.

RESULTS

There was a significant correlation (P < 0.05) between the number of pads used and the SF-36 domains of physical and vitality, between the number of incontinence episodes and the SF-36 domains of physical and role physical, between nocturia and the SF-36 domains of general and mental health, between the mean voided volume and the SF-36 domains of role physical and final, and between the mean voided volume and the incontinence-specific QoL score.

CONCLUSIONS

PTNS is useful for treating refractory urge incontinence and should at least be considered as a therapeutic alternative before resorting to aggressive surgery, as voiding and QoL variables significantly and quantifiably correlate in patients with refractory urge urinary incontinence who are treated with PTNS. Patients must have a reduction of >or = two pads/day before their QoL improves, and this might be the best definition of successful therapy for patients with urge urinary incontinence.

The role of urodynamics in the treatment of lower urinary tract symptoms in women

PURPOSE OF REVIEW

Urodynamic investigation was developed as an extension of patient history and physical examination in order to reveal the pathology of a patient's complaints. Much progress in standardizing definitions and procedures has been made in recent years. In particular, stress urinary incontinence and overactive bladder can be differentiated with urodynamics. The developed parameters, however, cannot distinguish the various types of stress urinary incontinence. Moreover the definition and diagnosis of voiding dysfunction is not clear. Finally our understanding of bladder sensations and the impact on voiding behaviour has only started to emerge. This review is about last year's publications that focus on urodynamics and lower urinary tract symptoms in women.

RECENT FINDINGS

Defining bladder outlet obstruction is based on voiding pressure, urinary flow speed and residual urine but standardization is lacking. Urodynamics to reveal occult stress urinary incontinence in patients with pelvic organ prolapse needs standardization of the reducing manoeuvres. The quest for urodynamic tools for distinguishing intrinsic sphincter deficiency from urethral hypermobility continues. Urodynamics are still not good enough to discriminate between treatment options for stress urinary incontinence. The use of urodynamics in overactive bladder is developing and has elicited new findings. Voiding habit seems to be independent from bladder sensations. Also bladder sensations appear to be imperfectly correlated with bladder filling. Even bladder volumes do not predict entirely bladder fullness sensations.

SUMMARY

In order to use urodynamics as a proper clinical tool, defining subtypes of stress urinary incontinence and standardization of urodynamics in pelvic organ prolapse and bladder outlet obstruction in women is needed.

Urinary incontinence: sphincter functioning from a urological perspective

Stress urinary incontinence (SUI) is a debilitating disorder caused by malfunctioning of the urethral sphincter. Anatomical and histological properties of the sphincter, its innervation and supporting structures are explained in relation to the closing mechanism of the bladder outlet. Urethral sphincter function is discussed from the passive concept of urethral pressure transmission to the 'hammock theory' and the role of the pubococcygeus muscles. SUI is caused by a combination of intrinsic sphincter deficiency and urethral hypermobility. The difficult interpretation of the parameters in urodynamic investigation to assess intrinsic sphincter deficiency (ISD) and/or urethral hypermobility is discussed. Electromyography (EMG) is valuable in the assessment of the overall urethral sphincter in relation to maneuvers (kinesiological EMG) and at the level of the muscle fiber (needle EMG). The diagnostic potential of circumferential surface EMG in the urethral sphincter is reviewed in relation to the EMG features of ISD.

Posterior tibial nerve stimulation in the treatment of voiding dysfunction: Urodynamic data

OBJECTIVES

To determine urodynamic changes and predictive factors in patients with voiding dysfunction who underwent 12 percutaneous tibial nerve stimulations.

METHODS

Thirty nine patients with chronic voiding dysfunction were enrolled in a prospective multicenter trial in the Netherlands (n = 19) and in Italy (n = 20). A 50% reduction in total catheterised volume per 24 hr was taken as a primary objective outcome measure. Patients' request for continuation of treatment was regarded as subjective success. Objective urodynamic parameters and bladder indices were determined. Odds ratios and their 95% confidence interval were computed as a measure for predictive power in order to reveal predictive factors (Pdet at Qmax, Qmax, BVE, and BCI).

RESULTS

Primary outcome measure was obtained in 41%, an additional 26% reduced their 24 hr residuals with more than 25%. Fifty nine percent of patients chose to continue treatment. Detrusor pressure at maximal flow, cystometric residuals, and bladder indices improved significantly for all patients (P < 0.05). Patients with minor voiding dysfunction were more prone to notice success (Odds ratio: 0.73; 95% CI: 0.51-0.94).

CONCLUSIONS

PTNS is a young treatment modality, minimally invasive, and easily accessible. It might be an attractive first line option for patients with (minor) voiding dysfunction.

Bladder filling by autologous urine production during cystometry: a urodynamic pitfall!

AIMS

The rate of autologous urine production should not have a major disturbing influence on cystometric urodynamic parameters such as first filling sensation, normal desire to void, strong desire to void, and cystometric bladder capacity. Instructions to patients and drinking behavior can have considerable impact, especially if filling cystometry is preceded by free uroflowmetry. We studied the influence of autologous urine production during filling cystometry on total bladder volume.

METHODS

Urodynamic investigations performed between September of 2000 and February of 2001 were analyzed. Only those urodynamic investigations for which total bladder capacity could be calculated were taken into account (i.e., catheterization before and after cystometry and no urine loss during the investigations).

RESULTS

After screening, 186 investigations were used for further analysis. Mean filled volume (external infusion plus autologous urine production) was 346 +/- 152 mL, but mean real bladder capacity (i.e., voided volume + residual urine) was 391 +/- 170 mL. In all patients, 14% extra urine was produced due to autologous urine production (mean filling rate, 6.1 mL/min). In 42% of the investigations, the real bladder capacity was more than 110% of the infused volume. In 18% of the patients, the contribution of natural bladder filling was more than 25% of the infused volume.

CONCLUSIONS

Natural bladder filling plays a substantial role during filling cystometry and has a disturbing influence on calculated urodynamic parameters. Attention should be paid to patient instructions before the urodynamic investigation. The combination of free uroflowmetry followed by filling cystometry should be avoided. This avoidance is especially important if interventional studies are performed. Careful interpretation of studies depending on bladder capacity parameters is mandatory, and such parameters should be corrected for autologous bladder filling.