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Objectives: To assess clinical follow‐up data over 24 months, comparing the use of a curved vs straight stylet in patients undergoing sacral neuromodulation using the standardized tined lead implantation technique. Patients and Methods: We conducted a single tertiary‐centre, prospective study between August 2013 and June 2015 involving 40 patients with overactive bladder and 15 with non‐obstructive urinary retention refractory to first‐line treatment. The primary outcome was successful tined lead procedure according to intention‐to‐treat analyses at 12 and 24 months. The secondary outcome was number of optimal electrode configurations during programming. Statistical analysis was performed using plain non‐parametric tests for numerical and categorical data. Results: Successful tined lead procedures were achieved in 33 of 35 patients (94%) implanted with the curved stylet compared with 13 of 20 patients (65%) implanted with the straight stylet (P = 0.005). Intention‐to‐treat analyses at 12 and 24 months showed success rates of 94% and 91%, respectively, in the curved stylet group vs 65% and 45%, respectively, in the straight stylet group (P = 0.002 and P < 0.001). In the curved stylet group, 60% and 25% of the electrode configurations were considered optimal and poor, respectively, vs 40% and 37%, respectively, in the straight stylet group (P < 0.001). Conclusions: The use of the standardized implantation technique with the curved stylet led to more successful tined lead procedures, better success rates after 2 years of follow‐up and a greater number of optimal electrode configurations when compared to use of the straight stylet. [ABSTRACT FROM AUTHOR]

Objective: To assess whether the utilisation of a motor response of <3 V during Stage 1 sacral neuromodulation (SNM) results in better clinical outcomes compared to >4 V in patients with overactive bladder (OAB) or urinary retention symptoms. Patients and Methods: An observational, retrospective, double cohort review was conducted of 339 female patients who had experienced medically recalcitrant OAB or urinary retention symptoms. Between September 2001 and September 2014, both cohorts underwent successful Stage 1 to Stage 2 SNM placement. Group A, included 174 women with a motor response at ≤3 V; and Group B, evaluated 110 women with a motor response at ≥4 V for medically recalcitrant OAB. Group C, compared 33 women with a motor response at ≤3 V; and Group D, documented 22 women with a motor response at ≥4 V for non‐obstructive urinary retention. Patients completed 3‐day voiding diaries, the Urogenital Distress Inventory‐6 (UDI‐6), Incontinence Impact Questionnaire‐7 (IIQ‐7), and Patient Global Impression of Improvement Questionnaire. Results: The mean ( sd) follow‐up was 116.3 (30.3) months in Group A and 112 (34.6) months in Group B (P < 0.354); 150.5 (20.4) months in Group C and 145.8 (17.2) months in Group D (P < 0.38). Successful conversion of Stage 1 to Stage 2 showed statistically significant improvement for both <3‐V groups (Groups A and C). Group A had a 93.5% (174/186) conversion rate vs 72.3% (110/152) in Group B for OAB symptoms (P < 0.001). Group C had a 94% (34/36) conversion rate vs 70% (21/30) in Group D (P < 0.017). Defined as a ≥50% reduction in frequency, urgency, urgency incontinence and nocturia, and UDI‐6 and IIQ‐7 scores, the success rate for Group A was 82.1% (143/174) and for Group B was 63% (69/110) (P < 0.001). The mean battery life improved in both <3‐V cohorts (P < 0.001). Annual reprogramming sessions were reduced in Group A and Group C (P < 0.001). Subset analysis of variance showed no statistical improvement in most patient outcomes when 1‐V subjects were compared to 2‐ and 3‐V cohorts. However, 32% of 1‐V patients (P < 0.001) noted the onset of severe pelvic/perirectal pain and big toe plantar flexion movement with small increments in voltage (0.1–0.2 V) during reprogramming. Only 7% of 2‐V and 1% of 3‐V patients experienced this complication. Conclusions: Significant improvement was noted (up to 40%) in most clinical voiding parameters in the <3‐V patients for both OAB and urinary retention. While <3 V will still statistically improve patient outcomes, a voltage <2 V may elicit self‐reprogramming pain with severe bellows and plantar flexion movement, which may discourage patients from therapy adjustments. We recommend randomised, controlled trials to confirm these results. [ABSTRACT FROM AUTHOR]

Objective To report our long-term experience of sacral neuromodulation ( SNM) for various lower urinary tract dysfunctions but with a focus on efficacy, safety, re-interventions and degree of success. Patients and Methods This is a single tertiary referral centre study that included 217 patients (86% female) who received an implantable pulse generator ( IPG) ( Interstim™, Medtronic, Minneapolis, USA) between 1996 and 2010. Success was considered if the initial ≥50% improvement in any of primary voiding diary variables persisted compared with baseline, but was further stratified. Results The mean duration of follow-up was 46.88 months. Success and cure rates were ≈70% and 20% for urgency incontinence, 68% and 33% for urgency frequency syndrome and 73% and 58% for idiopathic retention. In those patients with an unsuccessful therapy outcome, the mean time to failure was 24.6 months after implantation. There were 88 (41%) patients who had at least one device or treatment related surgical re-intervention. The re-intervention rate was 1.7 per patient with most of them (47%) occurring ≤2 years of follow-up. Conclusions SNM appears effective in the long-term with a success rate after definitive IPG implant of ≈70% and complete cure rates ranging between 20% and 58% depending on indication. Patients with idiopathic retention appear to do best. The re-intervention rate is high with most occurring ≤2 years of implantation. It is likely that with the newer techniques used, efficacy and re-intervention rates will improve. [ABSTRACT FROM AUTHOR]

What's known on the subject? and What does the study add? Sacral neuromodulation ( SNM) is an effective treatment option of different pelvic-related dysfunctions. SNM evaluation by either temporary or permanent electrodes is generally accepted. Extended testing with temporary electrodes has been reported on before but less is known about infection-related risks during prolonged evaluation with definitive electrodes., The present findings show that prolonged testing (mean = 52.3 days) with permanent electrodes does not increase infection-associated explantation rates, although bacterial colonization was found in more than one-third of the patients. Prolonged SNM evaluation under everyday conditions might improve long-term success., Objective To evaluate the impact of prolonged stage 1 testing on bacterial electrode colonization, infection and treatment success., Materials and Methods In all, 21 patients who underwent sacral neuromodulation ( SNM) for periods ≥1 month were prospectively evaluated; nine patients had overactive bladder syndrome ( OAB), 10 had urinary retention, two had faecal incontinence ( FI), and 13 had diabetes and overweight/obesity., After stage 1 testing electrode extension leads were microbiologically analysed to assess bacterial colonization., The primary measurements were pre- and post- SNM treatment comparisons based on patient-agreed criteria using an increased 70% minimum improvement rate; secondary measurements were bacterial colonization and impact of infection., Results The mean stage 1 evaluation period was 52.3 days; 16 patients (76%) progressed to stage 2, and five patients were explanted due to inadequate improvement (<70%)., There was bacterial colonization in 42.9% of patients and 38.2% of extension leads., Stage 2 patients showed no infection or wound-healing disorders at a mean follow-up of 33.9 months., The success rate for stage 2 implantation treatment was 94%., Conclusions There are few studies in the literature evaluating SNM testing periods vs the risk of clinically relevant implant infection rates. The present study shows that prolonged testing could potentially enhance treatment efficacy without infection-related explantations of the chronic implant, despite the identification of bacteria., SNM-implanted patients with diabetes mellitus or obesity should be followed closely., Clinicians might consider using prolonged testing under everyday conditions., Prolonged SNM stage 1 testing is a very effective minimally invasive treatment option to evaluate pelvic-related dysfunction. [ABSTRACT FROM AUTHOR]

OBJECTIVE: • To evaluate the long-term success and tolerability of sacral neuromodulation (SNM) in the control of the symptoms of bladder pain syndrome (BPS). METHODS: • This was a retrospective study of all patients with BPS who underwent peripheral nerve evaluation and then SNM in our department of urology by a single surgeon from 1994 till 2008. The global response assessment scale was used to evaluate the outcome of the SNM. RESULTS: • A total of 78 patients fulfilled the International Consultation on Incontinence clinical criteria for BPS and showed cystoscopic evidence of glomerulation or ulcer as recommended by the European Society for the Study of Interstitial Cystitis/ Painful Bladder Syndrome. All patients failed conservative management before considering SNM. • Permanent SNM implant was performed in patients who showed at least 50% improvement in their symptoms with a temporary peripheral nerve evaluation test. Median follow up was 61.5 months ( SD ± 27.7). Good long-term success of the SNM was seen in 72% of the patients. • Presence of urgency was a positive predictor of the long-term success of the implant. The explantation rate was 28%. The commonest reason for explantation was poor outcome (54% of the failed patients). The revision rate was 50%. • The most common indication for revision was lack of stimulation sensation and worsening of symptoms. The average durability of the pulse generator battery was 93 months. CONCLUSION: • SNM is an effective treatment to control the symptoms of BPS. It should be considered before any major invasive surgical intervention if conservative measures have failed. It is a minimally invasive, safe procedure with good longterm outcome. However, the revision rate is high and patients require lifelong follow-up. [ABSTRACT FROM AUTHOR]

The article discusses updates on sacral neuromodulation in the management of lower urinary tract dysfunction in 2010 in the Netherlands. It mentions that the SNM has no precise mode of action and its effects can only be explained through modulation of reflex pathways at the spinal cord level. In this regard, it cites experimental work in animals, human volunteers and patients to better understand the physical problems and find the appropriate procedures.

Study Type – Aetiology (case series) Level of Evidence 4 OBJECTIVE To examine brain responses to bladder filling in young women with Fowler’s syndrome (FS, a sphincter abnormality manifested by impaired voiding and bladder sensation), treated with sacral neuromodulation (SNM). PATIENTS AND METHODS Six women, aged 18–39 years with FS underwent functional brain magnetic resonance imaging (fMRI) immediately after SNM and when untreated (baseline). Data were collected at four sessions: after SNM with an empty and a full bladder, and at baseline with an empty and a full bladder. In each session, 280 whole-brain scans were acquired while repeatedly infusing and withdrawing 50 mL of saline, using push-buttons to report changing desire to void. Data were analysed using Statistical Parametric Mapping. RESULTS At baseline with an empty bladder, extensive responses (contrast = infusion–withdrawal) were almost exclusively negative (‘deactivations’), e.g. in the right insula, seat of visceral sensation. Increased bladder volume and/or SNM treatment reduced deactivations and strengthened normal (positive) responses, e.g. in the periaqueductal grey (PAG) terminus of ascending spinal afferents. At baseline, there was significant correlation of brain responses with maximum urethral closure pressure. CONCLUSION These data show that brain responses to bladder filling are abnormal in FS. The explanation for this that best explains the evidence is that the primary abnormality is an overactive urethra that generates abnormally strong inhibitory afferent signals, so effectively blocking bladder afferent activity at the sacral level and deactivating the PAG and higher centres, with consequent loss of bladder sensation and ability to void. Apparently, a normal mechanism for suppression of incontinence involving the striated urethral sphincter becomes exaggerated in FS and prevents voiding. SNM seems to act at the sacral level, by blocking inhibition by urethral afferents. [ABSTRACT FROM AUTHOR]

OBJECTIVE To investigate whether prolonged sacral neuromodulation (SNM) testing induces a substantial risk of infection because of the percutaneous passage of the extension wire. PATIENTS AND METHODS A consecutive series of 20 patients with negative prolonged SNM testing for ≥14 days who underwent tined-lead explantation were prospectively evaluated. The explanted tined leads were sent for microbiological examination . The tined lead, gluteal, and extension wire incision sites were investigated for clinical signs of infection according to the Centers for Disease Control and Prevention classification system. RESULTS In all, 17 patients had bilateral and three unilateral implanted tined leads. The median (range) test period was 30 (21–62 days). Bacterial growth ( Staphylococcus species) was detected in four of 20 (20%) patients on seven of 37 (19%) explanted tined leads. There were clinical signs of infection in one of 20 (5%) patients at none of 37 tined lead, one of 20 (5%) gluteal, and none of 20 extension wire incision sites. There were no clinical signs of infection in the remaining three of four patients with bacterial growth. CONCLUSIONS After prolonged tined-lead testing, we found an infection rate comparable to that reported with the usual short test period. In addition, most patients with bacterial growth on tined leads showed no clinical signs of infection. Thus, prolonged tined-lead testing does not seem to induce clinically relevant infection, warranting randomized trials. [ABSTRACT FROM AUTHOR]

The article discusses the efficacy of sacral neuromodulation (SNM) for treating the symptoms of overactive bladder syndrome and non-obstructive urinary retention. SNM involves continuous electrical stimulation of the sacral nerves to inhibit or activate the neural reflexes that influence the bladder, sphincter, and pelvic floor. A multicenter randomized controlled trial was used to evaluate the efficacy of SNM in patients with refractory urge urinary incontinence.

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

OBJECTIVES To report our 10-year experience of sacral neurostimulation (SNS) for women in urinary retention, comparing the original one-stage with the newer two-stage technique, as SNS therapy is a well-established treatment for urinary retention secondary to urethral sphincter overactivity (Fowler’s syndrome). PATIENTS AND METHODS Between 1996 and 2006, 60 patients with urinary retention had a SNS device inserted; their case records were reviewed and data on efficacy, follow-up, need for continued clean intermittent self-catheterization (CISC), complications and operative revision rate were assessed. RESULTS Overall, 43 of 60 (72%) women were voiding spontaneously, with a mean postvoid residual volume of 100 mL; 30 (50%) no longer needed to use CISC. During a total of 2878 months of SNS experience, adverse event episodes included lead migration in 20, ‘box-site’ pain in 19, leg pain/numbness in 18 and loss of response/failure in 18 patients; 53% of the women required a surgical revision related to their implanted stimulator. The efficacy of the two-stage was similar to that of the one-stage procedure (73% vs 70%). Women with a normal urethral sphincter electromyogram had worse outcomes than women with an abnormal test (43% vs 76%). Although the efficacy was no different in those taking analgesia/antidepressant medication, this group of women had a higher surgical revision rate. Failure and complications for the one-stage procedure were not restricted to the early follow-up period. The mean battery life of the implant was 7.31 years. CONCLUSIONS SNS has sustained long-term efficacy but the procedure has a significant complication rate. At present, the two-stage technique has comparable efficacy to the one-stage technique but a longer-term follow-up is required. The National Institute of Clinical Excellence recommended the use of SNS in women with urinary incontinence who fail to respond adequately to anticholinergic therapy, but patients choosing this treatment should be made aware of the high complication rate associated with the procedure. [ABSTRACT FROM AUTHOR]

OBJECTIVE To investigate to what extent antagonists of spinal neurotransmitters interact with the effects of sacral neuromodulation in a rat model of a chronically hyperactive urinary bladder. MATERIALS AND METHODS In female rats the urinary bladder was instilled with turpentine oil 2.5% to induce cystitis. After surviving for 10 days the rats were anaesthetized with urethane, the bladder catheterized and connected to a pressure transducer. Stimulating electrodes were placed in the sacral foramina bilaterally. The spinal cord was exposed by a laminectomy, and a small pool was placed on the cord for intrathecal administration of neurotransmitter antagonists. Sacral neuromodulation was applied before and after administering the antagonists. The antagonists used were: memantine, an antagonist for N-methyl- d-aspartate (NMDA) receptors; CNQX, an antagonist for non-NMDA receptors, and L-NAPNA, a blocker of nitric oxide synthase. RESULTS With no electrical neuromodulation, memantine and L-NAPNA abolished the cystitis-induced bladder contractions for ≈ 4 and ≈ 37 min, respectively. The effect of CNQX was similar to that of artificial cerebrospinal fluid. Electrical sacral modulation with no antagonists also transiently abolished the bladder contractions; at the highest intensity used, the pause was 2–3 min. Superfusion of the spinal cord with CNQX reduced this effect of neuromodulation significantly, whereas memantine had no influence, and L-NAPNA increased the neuromodulation-induced pause. CONCLUSIONS The results suggest that non-NMDA receptors are involved in the effects of sacral neuromodulation, whereas NMDA receptors appear to have no role. Nitric oxide is essential for maintaining the chronic hyperactive state of the urinary bladder. [ABSTRACT FROM AUTHOR]

OBJECTIVE To investigate different stimulation signals for the peripheral nerve evaluation test (PNE, carried out before implanting a sacral neuromodulator for functional voiding dysfunction) in an animal model and to determine their efficacy, as up to 80% of patients do not respond to the PNE test. MATERIALS AND METHODS PNE foramen electrodes were placed in the S3 of 12 anaesthetized Göttingen minipigs. First, detrusor instabilities were induced by the intravesical instillation of formalin. A 10-min stimulation phase with both a quasi-trapezoidal (QT) signal and a rectangular signal followed. An interval of 30 min elapsed between the series of stimulations. The attained bladder pressure values were registered on a urodynamic unit and evaluated as contractions and amplitudes per minute. Six minipigs were treated in the same way but were not stimulated and served as a control group. RESULTS After formalin instillation, the mean (sd) number of involuntary detrusor contractions was 3.5 (0.8)/min and the sum of amplitudes 7.2 (1.1) cmH2 O/min. Subsequent NaCl instillation and QT-stimulation reduced the contractions to 0.3 (0.3)/min and the sum of amplitudes to 0.8 (0.4) cmH2 O/min. Stimulation with a rectangular signal, as used in the PNE test, followed after an interval of 10 min, giving 1.1 (0.1) contractions/min and a sum of amplitudes of 5.1 (2.4) cmH2 O/min. Within the control group there was no significant reduction. CONCLUSIONS These results show that QT-stimulation suppresses uncontrollable detrusor contractions in the minipig more effectively than the conventional rectangular stimulation presently applied in sacral neuromodulation. [ABSTRACT FROM AUTHOR]

The article presents medical guidelines on how to treat patients with overactive bladder (OAB) symptom. The International Consultation on Incontinence (ICI) and the European Association of Urology have made second-line therapy which involved lifestyle intervention, pelvic floor muscle training and pharmacological therapy. Information regarding the clinical responses of BTX-A injection and sacral neuromodulation (SNM) is also presented.

To review the long-term results of sacral nerve stimulation in the treatment of women with Fowler's syndrome, over a 6-year period at one tertiary referral centre. Between 1996 and 2002, 26 women with urinary retention were treated by implanting a sacral nerve stimulator. Their case records were reviewed for follow-up, complications and revision procedures, and the most recent uroflowmetry results. There were 20 patients (77%) still voiding spontaneously at the time of review (with two having deactivated their stimulator because of pregnancy). Fourteen patients (54%) required revision surgery, and the most common complications included loss of efficacy, implant-related discomfort and leg pain. The mean postvoid residual volume was 75 mL and mean maximum flow rate 20.8 mL/s. In young women with retention, for whom there is still no alternative to lifelong self-catheterization, sacral neuromodulation is effective for up to 5 years after implantation. However, there was a significant complication rate, in line with other reports, which may be improved by new technical developments. [ABSTRACT FROM AUTHOR]