Superficial peroneal neuromodulation of nonobstructive urinary retention induced by prolonged pudendal afferent activity in cats.

The purpose of this study is to determine whether superficial peroneal nerve stimulation (SPNS) can improve nonobstructive urinary retention (NOUR) induced by prolonged pudendal nerve stimulation (PNS). In this exploratory acute study using eight cats under anesthesia, PNS and SPNS were applied by nerve cuff electrodes. Skin surface electrodes were also used for SPNS. A double lumen catheter was inserted via the bladder dome for bladder infusion and pressure measurement and to allow voiding without a physical urethral outlet obstruction. The voided and postvoid residual (PVR) volumes were also recorded. NOUR induced by repetitive (4-13 times) application of 30-min PNS significantly (P < 0.05) reduced voiding efficiency by 49.5 ± 16.8% of control (78.3 ± 7.9%), with a large PVR volume at 208.2 ± 82.6% of control bladder capacity. SPNS (1 Hz, 0.2 ms) at 1.5-2 times threshold intensity (T) for inducing posterior thigh muscle contractions was applied either continuously (SPNSc) or intermittently (SPNSi) during cystometrograms to improve the PNS-induced NOUR. SPNSc and SPNSi applied by nerve cuff electrodes significantly (P < 0.05) increased voiding efficiency to 74.5 ± 18.9% and 67.0 ± 15.3%, respectively, and reduced PVR volume to 54.5 ± 39.0% and 88.3 ± 56.0%, respectively. SPNSc and SPNSi applied noninvasively by skin surface electrodes also improved NOUR similar to the stimulation applied by a cuff electrode. This study indicates that abnormal pudendal afferent activity could be a pathophysiological cause for the NOUR occurring in Fowler's syndrome and a noninvasive superficial peroneal neuromodulation therapy might be developed to treat NOUR in patients with Fowler's syndrome.

Myeloradiculoneuropathy due to vitamin B12 deficiency: an unusual clinical and radiological presentation.

A 42-year-old man from rural India presented with asymmetric progressive paraparesis mimicking compressive dorsal myelopathy, followed by distal upper limb, truncal and neck-flexor weakness, further complicated by acute urinary retention. His sensory deficits were marked by loss of joint position sense (JPS) and graded loss of vibration sense, along with a definite sensory level. Deep tendon jerks were hypo-to-areflexic, plantar was bilaterally extensor. He had become less attentive and occasionally failed to keep track with conversations. A syndromic diagnosis of myeloradiculoneuropathy with cognitive impairments was made. Further tailored investigations revealed vitamin B12 deficiency with positive anti-parietal cell antibody. Diagnosis of subacute combined cord degeneration (SACD) was confirmed. Neuro-imaging revealed intramedullary intensity changes only along lateral aspect of spinal cord instead of characteristic posterior involvement. Following parenteral vitamin B12 supplementation, patient started showing improvement in motor power and subjective sensory symptoms. His bladder symptoms persisted initially, however recovered finally after 6 months.

A Supervised 3 Weeks Test Phase in Sacral Neuromodulation with a 1-Year Followup.

PURPOSE: We sought to determine whether prolonged interventional test phase increases cumulative success rate and compared success rates between early responders (ie within 1 week) and those in need for reprogramming (due to lack of efficacy) of sacral neuromodulation after 1-year followup. MATERIALS AND METHODS: In a single tertiary center prospective study (August 2015 to November 2018) 90 patients refractory to first line treatment were eligible for sacral neuromodulation, including 48 overactive bladder wet (53%), 8 overactive bladder dry (9%) and 34 nonobstructive urinary retention (38%). Patients were evaluated at weekly intervals during test phase and those not successful were reprogrammed. This could be repeated after the second week. Primary outcome was success rate after 3-week test phase and after 1-year followup. Statistical analysis was done by nonparametric tests for numeric (Mann-Whitney U) and categorical (chi2) data. RESULTS: After 3 weeks of test period 56 patients (62%) were considered successful. Prolonged interventional testing increased cumulative success. A 1-year followup showed no significant difference in success rate between early responders and those in need for reprogramming (chi2, p=0.562). There was no difference in age (Mann-Whitney U, p=0.222), sex (chi2, p=0.952) or indication (chi2, p= 0.975). CONCLUSIONS: A 3-week test phase with close followup increases cumulative success rate. During this supervised 3-week test phase 42% of the initial nonresponders after the first week became successful candidates after reprogramming. Patients who required this additional programming did equally as well as those without need for reprogramming. A supervised 3-week test phase is therefore strongly recommended.

Sacral Neuromodulation: Determining Predictors of Success.

OBJECTIVE: To determine predictors of success for sacral neuromodulation in women with overactive bladder, urinary retention, and fecal incontinence. METHODS: A retrospective chart review was performed on women who underwent a staged sacral neuromodulation implantation between 2007 and 2018. Clinical and procedural characteristics were recorded. Presence of intraoperative motor responses in either all 4 or <4 electrodes were used to group women. Endpoints included completion of stage II implant, tined lead revision, and patient-reported success. RESULTS: In 198 women with a mean age of 62.9 years (SD+/- 14.7), completion of stage II implant occurred in 92.4% of women, and 83.3% of these women reported success at the first postoperative visit. Continued success at 6 months was reported in 70.3%. Lead revision was noted in 23.0%. Age >65 years (odds ratio [OR] = 0.2, 95% confidence interval [CI] = 0.06-0.8) and prior onabotulinumtoxinA (onaBoNT-A) (OR = 0.2, 95% CI = 0.06-0.9) were negative predictors for completion of stage II implant on multivariable analysis. Also, prior pelvic floor physical therapy was a significant negative predictor of postoperative patient-reported success on multivariable analysis (OR = 0.25, 95% CI = 0.1-0.6). There were no differences seen in women who had motor responses with either all 4 electrodes or <4 electrodes in any endpoint (P > .05). CONCLUSION: Patient age >65 and history of prior onaBoNT-A were associated with failure to complete stage II implant. Women with prior pelvic floor physical therapy were less likely to report success after sacral neuromodulation. Motor responses in <4 electrodes during lead testing did not impact patient-reported success.

Sacral nerve stimulation for refractory OAB and idiopathic urinary retention: Can phenotyping improve the outcome for patients: ICI-RS 2019?

AIMS: Sacral nerve stimulation (SNS) is widely used to treat refractory idiopathic overactive bladder (OAB) and idiopathic urinary retention. However, clinical outcomes are variable and understanding predictive factors for success or side-effects would enable personalization of therapy and optimization of outcomes. At the International Consultation on Incontinence-Research Society meeting 2019, a Think Tank was convened to discuss how advances in the basic science study of SNS may be translatable into clinical practice to improve outcomes of patients undergoing SNS treatment. METHODS: We conducted a literature review and expert consensus meeting focusing on current methods of phenotyping patients and specifically, how advances in basic science research of the mechanism of action of SNS can be translated into clinical practice to improve patient selection for therapy. RESULTS: The terms "Idiopathic OAB" and "idiopathic urinary retention" encompass several underlying pathophysiological phenotypes. Commonly, phenotyping is based on clinical and urodynamic factors. Animal studies have demonstrated that high-frequency stimulation can produce rapid onset, reversible conduction block in peripheral nerves. Altering stimulation parameters may potentially enable personalization of therapy depending upon the clinical indication in the future. Similarly, advances in conditional and closed-loop stimulation may offer greater efficacy for certain patients. Phenotyping based on psychological comorbidity requires further study to potentially optimize patient selection for therapy. CONCLUSIONS: Idiopathic OAB and idiopathic urinary retention are heterogenous conditions with multiple potential underlying phenotypes. Tailoring stimulation parameters to the needs of each individual according to phenotype could optimize outcomes. Assessing psychological comorbidity may improve patient selection. Areas for further research are proposed.

Superficial peroneal neuromodulation of nonobstructive urinary retention in cats.

AIMS: To determine if superficial peroneal nerve stimulation (SPNS) can improve nonobstructive urinary retention (NOUR). METHODS: In α-chloralose anesthetized cats, NOUR was induced by repetitive application (4-16 times) of 30-minute tibial nerve stimulation (TNS: 5 Hz frequency, 0.2 ms pulse width) at 4 to 6 times threshold intensity (T) for inducing toe twitches. SPNS (1 Hz, 0.2 ms) at 2 to 4 times threshold intensity (T) for inducing posterior thigh muscle contractions was applied either continuously (SPNSc) during a cystometrogram (CMG) or during voiding (SPNSv) by a surgically implanted cuff electrode or by skin surface electrodes to determine if the stimulation reduced NOUR induced by prolonged TNS. RESULTS: During control CMGs, efficient (86.4% ± 5.5%) voiding occurred with a postvoid residual (PVR) volume equal to 14.9% ± 6.2% of control bladder capacity. NOUR elicited by prolonged TNS significantly (P < .05) increased bladder capacity to 168.6% ± 15.5% of control, reduced voiding efficiency to 30.4% ± 4.8%, and increased PVR to 109% ± 9.2% of control. Using the implanted cuff electrode, SPNSc and SPNSv significantly (P < .05) increased voiding efficiency to 66.7% ± 7.4% and 65.0% ± 5.9%, respectively, and reduced PVR to 52.2% ± 11.4% and 64.3% ± 11.6%, respectively. SPNSc but not SPNSv significantly (P < .05) reduced bladder capacity to 133.4% ± 15% of control. Transcutaneous SPNSv but not SPNSc also significantly (P < .05) reversed the TNS-induced NOUR responses. CONCLUSIONS: This study shows that SPNS is effective in reversing NOUR induced by prolonged TNS. Transcutaneous SPNS provides the opportunity to develop a noninvasive neuromodulation therapy for NOUR to treat more patients than current sacral neuromodulation therapy.

Prolonged nonobstructive urinary retention induced by tibial nerve stimulation in cats.

Nonobstructive urinary retention (NOUR) is a medical condition without an effective drug treatment, but few basic science studies have focused on this condition. In α-chloralose-anesthetized cats, the bladder was cannulated via the dome and infused with saline to induce voiding that could occur without urethral outlet obstruction. A nerve cuff electrode was implanted for tibial nerve stimulation (TNS). The threshold (T) intensity for TNS to induce toe twitch was determined initially. Repeated (6 times) application of 30-min TNS (5 Hz, 0.2 ms, 4-6T) significantly (P < 0.05) increased bladder capacity to 180% of control and reduced the duration of the micturition contraction to 30% of control with a small decrease in contraction amplitude (80% of control), which resulted in urinary retention with a low-voiding efficiency of 30% and a large amount of residual volume equivalent to 130% of control bladder capacity. This NOUR condition persisted for >2 h after the end of repeated TNS. However, lower frequency TNS (1 Hz, 0.2 ms, 4T) applied during voiding partially reversed the NOUR by significantly (P < 0.05) increasing voiding efficiency to 60% and reducing residual volume to 70% of control bladder capacity without changing bladder capacity. These results revealed that tibial nerve afferent input can activate either an excitatory or an inhibitory central nervous system mechanism depending on afferent firing frequencies (1 vs. 5 Hz). This study established the first NOUR animal model that will be useful for basic science research aimed at developing new treatments for NOUR.

[Sacral neuromodulation in under- and overactive detrusor-quo vadis? : Principles and developments]. / Sakrale Neuromodulation bei unter- und überaktivem Detrusor ­ quo vadis? : Prinzipien und Entwicklungen.

BACKGROUND: Sacral neuromodulation (SNM) has been used in the treatment of refractory overactive bladder syndrome, nonobstructive urinary retention and faecal incontinence for almost 40 years now. It is not to be confused with the sacral anterior root stimulation which is exclusively used for bladder dysfunction due to spinal paraplegia. MECHANISM OF ACTION: The principles of SNM are yet to be fully understood. Nevertheless, there is proof of modulating the activity of several micturition-associated, afferent neurons in the spine, brainstem and cerebrum. Thus, premature detrusor contractions are suppressed, the desire to void is delayed and detrusor-sphincter coordination improves. TECHNIQUES OF IMPLANTATION AND STIMULATION: Motor reactions are an important indicator of correct electrode placement. The implantation procedure consists of two stages with an initial trial phase to determine the best possible treatment response through an external generator before implanting the whole stimulating device. Yearly check-up examinations are recommended; wireless adjustments allow for long-lasting symptom reduction. INDICATION AND OUTCOME: Success rates in the treatment of the refractory overactive bladder syndrome and the non-obstructive urinary retention lie above 70% and can still be perceived as sufficient after 5 years of ongoing SNM therapy. There is also profound evidence of SNM being an effective option for patients with faecal incontinence or chronic obstipation. CONTRAINDICATIONS AND RISKS: Children, pregnant women and patients in need of frequent MRI examinations are usually not eligible for SNM therapy. Infection of the implant, technical failure (including lead displacement and battery depletion) and pain in the implantation site are important adverse effects which might require surgical revision. CONCLUSIONS: The indications for SNM in the German health care system can be expected to be expanded upon the chronic pelvic pain syndrome, erectile dysfunction and additional gastrointestinal conditions. Technical progress will continue to improve the risk-benefit ratio of SNM.

Do Urodynamic Findings Other Than Outlet Obstruction Influence the Decision to Perform a Transurethral Resection of Prostate?

OBJECTIVE: To determine if urodynamic findings other than high-pressure voiding influence the decision to perform a transurethral resection of prostate (TURP). METHODS: Four clinical scenarios were created featuring a healthy 65-year-old man. An electronic survey was distributed to members of the International Continence Society and the Society for Urodynamics, Female Pelvic Medicine and Urogenital Reconstruction. RESULTS: Eighty-six urologists responded (median age was 45-54 years, 62% described their practice as academic). Scenario 1: an incidental residual urine >1 L with detrusor underactivity. The majority (76%) would offer a TURP; however, the estimated chance that the residual volume would improve was only 57%. Scenario 2: retention with detrusor overactivity but no voluntary voiding contraction. The majority (72%) would offer a TURP; however, the average chance quoted that he would void was only 48%. Scenario 3: catheter-dependent retention and an underactive detrusor. The majority (89%) would offer a TURP; however, the average chance quoted that he would void was only 53%. Scenario 4: a man with only frequency and urgency, but urodynamic bladder outlet obstruction. The majority (90%) would offer him a TURP; however, the average chance that his frequency and urgency would improve was only 64%, and the average estimated postoperative risk of urgency incontinence was 33%. Willingness to offer TURP did not correlate with physician characteristics. CONCLUSION: Urodynamic findings other than bladder outlet obstruction were associated with modest perceived outcomes after TURP; however, despite this, urologists are still willing to offer this intervention.

Role of sacral neuromodulation in modern urogynaecology practice: a review of recent literature.

Sacral neuromodulation (SNM) offers promise in the therapy of many pelvic floor disorders. This innovative treatment has slowly gained popularity. A review of recent literature is presented in relation to its efficacy and complications in various pelvic floor conditions: overactive bladder and urge urinary incontinence, chronic urinary retention, painful bladder syndrome, pelvic pain and double incontinence. It is a minimally invasive, completely reversible safe procedure with good long-term outcomes. However, the treatment is costly, the revision rate is high and patients require life-long follow-up. SNM should always be considered in suitable patients before offering bladder augmentation procedures or urinary diversion or permanent catheterization for bladder dysfunction. SNM should also be considered in patients with double incontinence, after discussion in a urogynaecology/colorectal multidisciplinary team.

Sacral neuromodulation blocks pudendal inhibition of reflex bladder activity in cats: insight into the efficacy of sacral neuromodulation in Fowler's syndrome.

This study tested the hypothesis that sacral neuromodulation, i.e., electrical stimulation of afferent axons in sacral spinal root, can block pudendal afferent inhibition of the micturition reflex. In α-chloralose-anesthetized cats, pudendal nerve stimulation (PNS) at 3-5 Hz was used to inhibit bladder reflex activity while the sacral S1 or S2 dorsal root was stimulated at 15-30 Hz to mimic sacral neuromodulation and to block the bladder inhibition induced by PNS. The intensity threshold (T) for PNS or S1/S2 dorsal root stimulation (DRS) to induce muscle twitch of anal sphincter or toe was determined. PNS at 1.5-2T intensity inhibited the micturition reflex by significantly ( P < 0.01) increasing bladder capacity to 150-170% of control capacity. S1 DRS alone at 1-1.5T intensity did not inhibit bladder activity but completely blocked PNS inhibition and restored bladder capacity to control level. At higher intensity (1.5-2T), S1 DRS alone inhibited the micturition reflex and significantly increased bladder capacity to 135.8 ± 6.6% of control capacity. However, the same higher intensity S1 DRS applied simultaneously with PNS, suppressed PNS inhibition and significantly ( P < 0.01) reduced bladder capacity to 126.8 ± 9.7% of control capacity. S2 DRS at both low (1T) and high (1.5-2T) intensity failed to significantly reduce PNS inhibition. PNS and S1 DRS did not change the amplitude and duration of micturition reflex contractions, but S2 DRS at 1.5-2T intensity doubled the duration of the contractions and increased bladder capacity. These results are important for understanding the mechanisms underlying sacral neuromodulation of nonobstructive urinary retention in Fowler's syndrome.

Acute urinary retention after Black Widow envenomation: a case report.

Latrodectism following Black Widow envenomation is rare in Canada. We present the case of a previously healthy 50 year old male who presented with an acute abdomen, hypertension, and urinary retention. After a thorough work up it was determined to be as a result of a Black Widow spider bite. Due to climate change we may see more cases of Latrodectism in the future and it should be considered as a differential diagnosis in anyone presenting with an acute abdomen after an insect bite.

[Neuromodulation of lower urinary tract dysfunction]. / Neuromodulation bei Harnblasenfunktionsstörungen.

Neuromodulative procedures such as transcutaneous electrical nerve stimulation (TENS), transcutaneous/percutaneous tibial nerve stimulation (TTNS/PTNS), and sacral neuromodulation (SNM) are promising second-line treatments for refractory lower urinary tract dysfunction. Using these therapies, both storage and voiding disorders but also bowel dysfunction might be successfully treated. Although the mechanism of action of neuromodulation is not well understood, it seems to involve modulation of spinal cord reflexes and brain networks by peripheral afferents (genital/rectal, tibial and sacral afferents in the case of TENS, TTNS/PTNS, and SNM, respectively). Neuromodulative procedures might also be highly effective in the most desperate situations and further relevant developments are expected so that these innovative techniques will most likely become even more important in urology.

Clinical efficacy of intravesical electrical stimulation on detrusor underactivity: 8 Years of experience from a single center.

The aim of this study was to retrospectively evaluate the effectiveness of intravesical electrical stimulation (IVES) on detrusor underactivity (DU).From 2009 to 2016, a total of 105 patients with symptoms of DU who were treated with IVES were included in this retrospective study. The medical records, physical examination findings, urine culture results, and video-urodynamic studies were reviewed. Changes in post-void residual urine (PVR) and voiding efficiency (VE) were included for evaluation of efficacy. Patients achieving a >50% reduction in the PVR were regarded as responders. A >80% reduction in the PVR was considered obvious improvement. A questionnaire was administered to patients with bladder sensation.Of the 105 patients, the information of residual urine volume and voiding volume was obtained in 89 patients, and detailed pre- and post-IVES bladder sensation information was available on 96 patients. Of the 89 patients, 47.2% (42/89) were responders and achieved a >50% reduction in the PVR. Obvious improvement in the PVR, defined as a >80% reduction, occurred in 27% (24/89) of the patients. VE developed in 76.4% (68/89) of the patients, and 30.3% (27/89) of the patients increased >50%. Significant improvements in the PVR and VE were observed during IVES treatment (P < .05). Based on the questionnaire, bladder sensation developed and was sustained in 44.8% (43/96) of the patients.IVES provides a promising method for improving the PVR and VE in a majority of patients with DU. Thus, IVES is worth to further study and carry out.

The effects of neuromodulation in a novel obese-prone rat model of detrusor underactivity.

Obesity is a global epidemic associated with an increased risk for lower urinary tract dysfunction. Inefficient voiding and urinary retention may arise in late-stage obesity when the expulsive force of the detrusor smooth muscle cannot overcome outlet resistance. Detrusor underactivity (DUA) and impaired contractility may contribute to the pathogenesis of nonobstructive urinary retention. We used cystometry and electrical stimulation of peripheral nerves (pudendal and pelvic nerves) to characterize and improve bladder function in urethane-anesthetized obese-prone (OP) and obese-resistant (OR) rats following diet-induced obesity (DIO). OP rats exhibited urinary retention and impaired detrusor contractility following DIO, reflected as increased volume threshold, decreased peak micturition pressure, and decreased voiding efficiency (VE) compared with OR rats. Electrical stimulation of the sensory branch of the pudendal nerve did not increase VE, whereas patterned bursting stimulation of the motor branch of the pudendal nerve increased VE twofold in OP rats. OP rats required increased amplitude of electrical stimulation of the pelvic nerve to elicit bladder contractions, and maximum evoked bladder contraction amplitudes were decreased relative to OR rats. Collectively, these studies characterize a novel animal model of DUA that can be used to determine pathophysiology and suggest that neuromodulation is a potential management option for DUA.

The Impact of Duration of Complaints on Successful Outcome of Sacral Neuromodulation.

OBJECTIVES: The study aimed to evaluate whether the duration of complaints in patients with overactive bladder syndrome or non-obstructive urinary retention predicts the outcome of sacral neuromodulation (SNM). METHODS: All patients that underwent a SNM test period evaluation between 2011 and 2014, were included in this study. The duration of complaints was listed in 3 categories: (a) 0-5 years, (b) 5-10 years and (c) 10 years or longer. Analyses with chi square tests were performed to evaluate whether the duration of complaints are associated with outcome of SNM. RESULTS: In total, 130 patients were included. Most patients had a complaint duration of 0-5 years (n = 60). The test period was successful in 56% (n = 74) of the total group. Analyses showed that the duration of complaints is not significantly associated with outcome of SNM (p = 0.752), even when subdivided per indication, and also when possible confounders such as age at test and indication are taken into account (p = 0.720). CONCLUSION: Based on the results of this study, there is no relationship between duration of complaints and SNM outcome. SNM seems to remain a feasible treatment option, despite of possible anatomical or physiological changes within the lower urinary tract.

5-alpha-reductase inhibitor therapy postpones urine retention and prostate surgery in patients with prostate enlargement and a maximum uroflow rate of less than 15 ml/sec.

BACKGROUND: This study investigated the risk of transurethral resection of prostate (TURP) and acute urine retention (AUR) in relation to 5-alpha-reductase inhibitor (5ARI) therapy. METHODS: We identified 22,687 patients who were newly diagnosed with PE and low urinary tract symptoms (LUTS) between January 1, 2002 and December 31, 2011. We further classified study subjects who had moderate to severe LUTS and a maximum uroflow rate of less than 15ml/sec into three groups by their defined daily dose (DDD) of 5ARI used. The control group consisted of 7-28 cumulative DDD (cDDD) 5ARI users, while the short-term treatment group was 29-179cDDD 5ARI users, and the long-term treatment group was users of more than 180cDDD 5ARI. Each patient was monitored to identify those who subsequently developed TURP and AUR. RESULTS: TURP and AUR are detected in 5.6% of control group, 7.6% of short-term treatment group and 5.5% of long-term treatment group during 10-year follow up. Compared with the control group, there was no difference in the risk of TURP and AUR in the short-term and long-term treatment groups (HR = 1.41, 95% CI 0.76 to 2.62 and HR = 0.81, 95% CI 0.42 to 1.56, respectively). CONCLUSION: 5ARI therapy did not change the risk of TURP and AUR events in patients with PE, moderate to severe LUTS and a maximum uroflow rate of less than 15 ml/sec in 10 years of follow-up. But long-term 5ARI used can postpone AUR and TURP for 8.16 months.

Prediction of sacral neuromodulation treatment success in men with impaired bladder emptying-time for a new diagnostic approach.

INTRODUCTION: Detrusor underactivity (DU) is currently a topic that receives major attention within functional urology. Urologists are often confronted with men who present with voiding dysfunction without bladder outlet obstruction (BOO) or after desobstructive or neuromodulation treatment. Their impaired bladder emptying is suspected to be related to failure of detrusor contractile function. Earlier research indicated that patients with non-obstructive urinary retention (NOR), for example, detrusor underactivity (DU), have a lower success rate after sacral neuromodulation (SNM) compared to patients treated with SNM for storage dysfunction. However, predicting factors for treatment success in the NOR group have not yet been defined. METHODS AND EVIDENCE: The aim of this study was to assess whether the use of the new BOO-contractility (Maastricht-Hannover) nomogram can identify and predict SNM non-responders. Our results in 18 men showed that only 20% of patients below the 10th percentile, but 86% of men between the 10 and 25th percentiles of the nomogram can be treated successfully with SNM. All successfully treated patients voided without needing self- catheterisation. CONCLUSIONS: This pilot study showed for the first time that SNM treatment response in male patients with impaired bladder emptying can be predicted with the BOO-contractility (Maastricht-Hannover) nomogram. Men below the 10th percentile are likely to be treatment non-responders, whereas the majority of men above the 10th percentile are responders. Neurourol. Urodynam. 36:808-810, 2017. © 2016 Wiley Periodicals, Inc.