Research and progress on the mechanism of lower urinary tract neuromodulation: a literature review.

The storage and periodic voiding of urine in the lower urinary tract are regulated by a complex neural control system that includes the brain, spinal cord, and peripheral autonomic ganglia. Investigating the neuromodulation mechanisms of the lower urinary tract helps to deepen our understanding of urine storage and voiding processes, reveal the mechanisms underlying lower urinary tract dysfunction, and provide new strategies and insights for the treatment and management of related diseases. However, the current understanding of the neuromodulation mechanisms of the lower urinary tract is still limited, and further research methods are needed to elucidate its mechanisms and potential pathological mechanisms. This article provides an overview of the research progress in the functional study of the lower urinary tract system, as well as the key neural regulatory mechanisms during the micturition process. In addition, the commonly used research methods for studying the regulatory mechanisms of the lower urinary tract and the methods for evaluating lower urinary tract function in rodents are discussed. Finally, the latest advances and prospects of artificial intelligence in the research of neuromodulation mechanisms of the lower urinary tract are discussed. This includes the potential roles of machine learning in the diagnosis of lower urinary tract diseases and intelligent-assisted surgical systems, as well as the application of data mining and pattern recognition techniques in advancing lower urinary tract research. Our aim is to provide researchers with novel strategies and insights for the treatment and management of lower urinary tract dysfunction by conducting in-depth research and gaining a comprehensive understanding of the latest advancements in the neural regulation mechanisms of the lower urinary tract.

The 'Prostate Embolisation AS first-line therapY compAred to meDication in treatment naïVe men with prostAte eNlargement, a randomised ControllEd trial' (P-EASY ADVANCE): a randomised controlled trial of prostate embolisation vs medication for BPH.

OBJECTIVE: To compare prostate artery embolisation (PAE) to the combination of tamsulosin and dutasteride therapy as a potential first-line therapy for obstructive benign prostatic hyperplasia (BPH) in treatment-naïve patients in the 'Prostate Embolisation AS first-line therapY compAred to meDication in treatment naïVe men with prostAte eNlargement, a randomised ControllEd trial' (P-EASY ADVANCE). PATIENTS AND METHODS: A total of 39 men with enlarged prostates, moderate-severe lower urinary tract symptoms (LUTS) and obstructed/equivocal urodynamic studies (UDS), and who had no prior treatment for BPH, were randomised to receive either combined medical therapy with tamsulosin and dutasteride (medication) or PAE. Follow-up UDS, International Prostate Symptom Score (IPSS), uroflowmetry and ultrasound were performed at short- to medium-term intervals following interventions and compared to baseline. RESULTS: The medication and PAE treatment groups had similar baseline characteristics, including prostate volumes (87.8 and 85.4 mL respectively), maximum urinary flow rate (Qmax; 6.5 and 6.6 mL/s, respectively), IPSS (19.5 and 21, respectively) and obstructed UDS (79% and 74%, respectively). Both interventions improved voiding and bladder outflow obstruction from baseline, with more patients unobstructed after PAE (63%) compared to medication (28%) (P = 0.03). PAE patients had significantly greater reductions in prostate size (P < 0.001), incomplete emptying (P = 0.002), total IPSS (P = 0.032), Qmax (P = 0.006) and quality of life (P = 0.001). Altered ejaculation, erectile dysfunction and nausea were more common in the medication group. CONCLUSION: Prostate artery embolisation was more effective than combined medical therapy at reducing urinary obstruction, decreasing prostate volume and improving LUTS in patients with BPH who had not previously been treated. This is the first randomised control study to compare PAE and combined medical therapy in exclusively treatment-naïve patients and raises the potential of PAE as an alternative early treatment option for BPH. Further randomised comparative trials are planned to further validate the role of PAE in mitigating obstructive BPH.

Myelomeningocele operated in utero and the incontinent bladder pattern: Mid-term follow up of a prospective study.

INTRODUCTION: In-utero myelomeningocele repair is the gold standard treatment after the publication of the MOMS trial. We have performed a retrospective analysis from our prospective in-utero myelomeningocele closure database (started in 2011), and selected only patients with the incontinent bladder pattern according to the Leal da Cruz categorization (Leal da Cruz, et al. J Urol 2015) to review mid-term clinical outcomes. MATERIAL AND METHODS: We identified 30 patients with leaking pressure under 40 cmH20 (incontinent pattern) at first urodynamic evaluation (UE) from the whole cohort of 129 patients who underwent in-utero myelomeningocele closure. We selected patients with a minimum active follow-up of 48 weeks (4 years) to provide mid-term data. Patients were followed according to the same protocol with the proposal of yearly sonogram and UE. All clinical and radiological data were reviewed. RESULTS: We found 11 patients, with a mean age of 10.2 years old, median age at diagnosis of 19 weeks, surgery performed at 25.6 weeks and birth at 33.2 weeks. The mean follow-up was 81.73 months (6.81 years). Mean age at first urological evaluation was 5 months, and UE was 5.6 months. Febrile UTI incidence in the whole observation period was 27.3%. The average initial DLPP was 30 cmH2O. 71.4% of the patients had bladder capacity less than 50% of the expected age. Bladder compliance could not be determined in 63.7% of cases due to leakage. A total of 5.7 urodynamic studies per patient were performed. Surgery was recommended for 8 patients and done in 4 (36.3%). Surgery consisted of Macedo catheterizable reservoir and Macedo-Malone ACE, associated with urethral sling (2 patients) and bladder neck closure (2). It took an average of 5 UE before the final surgical decision was confirmed. Last urodynamic study showed persistent leakage and low DLPP in 3 patients, normal bladder pressure in 2 (under CIC and anticholinergics), and 1 patient changed his bladder pattern into a high risk group. All operated patients are fully continent (urinary >4hs) and fecal. CONCLUSION: Despite initially presenting a low risk for the most patients, we found surgery in 36.3% (4/11) and if we considered all cases with surgery indication proposed to treat urinary incontinence it would be even higher (72.7%).

Urodynamic analysis of the effect of electroacupuncture at different acupoints on the bladder after spinal cord injury.

OBJECTIVE: Guanyuan (CV4), Zhongji (CV3) and Sanyinjiao (SP6) are the most frequently used acupoints for treating neurogenic bladder after spinal cord injury (SCI). However, there has been no investigation to clarify the differences in effects of these acupoints in different types of neurogenic bladder. METHODS: The study was structured with a randomized, two-phase cross over design with a washout period. A routine urodynamic examination was performed first, then, in the order of grouping, electroacupuncture was performed on CV4, CV3, and SP6, respectively，and urodynamic examination was performed to observe the changes of urodynamic indexes in real time. RESULTS: When undergoing electroacupuncture at CV4, CV3, and SP6 in patients with neurogenic detrusor overactivity (DO), the bladder volume at the first occurrence of DO and maximum cystometric capacity increased (p < 0.05), but maximum detrusor pressure (Pdetmax) at DO decreased (p < 0.05), and the changes using CV4 and CV3 was more significantly than using SP6 (p < 0.05). And in patients with in neurogenic detrusor underactivity, there were no significant changes in maximum urinary flow rate and Pdetmax during urination (p > 0.05). CONCLUSION: The immediate relief effect of electroacupuncture at CV4, CV3 on DO was greater than at SP6.

Clinical Study on Low-Frequency Electrical Pulse Acupoint Stimulation Combined with Pelvic Floor Muscle Exercise in the Treatment of Urinary Incontinence after Radical Prostatectomy.

BACKGROUND: Urinary incontinence (UI) is a common complication after radical prostatectomy (RP). It has a great influence on the postoperative quality of life of patients. This study aims to explore the clinical efficacy of low-frequency electrical pulse acupoint stimulation combined with pelvic floor muscle exercise in the treatment of UI after RP. METHODS: The clinical data of 129 patients with UI after receiving RP in our hospital from July 2020 to July 2023 were retrospectively analysed. A total of 65 patients who received pelvic floor muscle exercise from July 2020 to January 2022 were set as the reference group. Of these patients, four were excluded, resulting in the inclusion of 61 cases. A total of 64 patients who received low-frequency electrical pulse acupoint stimulation combined with pelvic floor muscle exercise from February 2022 to July 2023 were classified into the observation group. Of these patients, four were excluded, and 60 cases were finally included. SPSS 23.0 was used to analyse the use of urine pads, recovery time of urinary control and improvement of urination in the two groups. RESULTS: Before treatment, no significant difference existed in the use of urine pads, urination condition, maximum flow rate, maximum cystometric capacity, maximum urethral closure pressure, abdominal leak point pressure and scores on Short-Form-36 Health Survey (SF-36) in both groups (p > 0.05). After treatment, the observation group had significantly lower use of urinary pads, urination frequency and leakage times; Significantly shorter recovery time of urinary control (p < 0.05); And significantly higher maximum flow rate, maximum cystometric capacity, maximum urethral closure pressure, abdominal leak point pressure and SF-36 scores than the reference group (p < 0.05). CONCLUSIONS: The combination of low-frequency electrical pulse acupoint stimulation and pelvic floor muscle exercise can improve clinical symptoms, shorten the recovery time of urinary control and improve urodynamics and quality of life in patients with UI after RP.

Why are continent catheterizable channels continent? A stomal pressure profilometry feasibility study.

INTRODUCTION: A continent catheterizable channel (CCC) may be a solution for patients with impaired bladder emptying and difficult transurethral access. Leakage of the CCC is a common complication. To prevent leakage, the pressure in the CCC has to be higher than the reservoir (bladder/pouch) pressure in at least one location. It has not been clearly defined through which mechanism(s) the CCC achieves continence. In this feasibility study, we measured the CCC pressure profile in adult patients with various types of CCC's with and without stomal leakage. METHODS: Adult patients with a CCC on a (augmented) bladder or pouch who underwent a urodynamic investigation between January and March 2023 were included. Next to the standard urodynamic investigation, a continuous stomal pressure measurement (CSP) and stomal pressure profilometry with empty bladder (SPP-1) and with filled bladder (SPP-2) of the CCC were performed. RESULTS: A total of 17 patients were included. It was technically possible to perform SPP-1 and SPP-2 in all patients, and to measure the CSP in 16/17 patients. The median maximum stomal pressures in SPP-1 and SPP-2 were 112 (interquartile range [IQR], 76-140) cmH2O and 120 (IQR, 92-140) cmH2O, respectively. Nine patients had stomal leakage during the urodynamic investigation. In five patients, the detrusor leak point pressure (dLPP) was low (<20 cmH2O). A pressure peak at the beginning of SPP-2 was absent in all patients with stomal leakage at low dLPP. CONCLUSION: SPP and CSP measurement in CCCs are feasible. We found differences in SPP-2 between patients with and without leakage at low dLPP, indicative of a role of the intravesical tunnel in continence or high dLPP. The results of this study may improve our understanding of the physiology and dynamics of CCCs as well as the management of CCC-related complications.

Computational fluid dynamics of bladder voiding using 3D dynamic MRI.

Over the last couple of decades, image-based computational fluid dynamics (CFD) has revolutionized cardiovascular research by uncovering hidden features of wall strain, impact of vortices, and its use in treatment planning, as examples, that were simply not evident in the gold-standard catheterization studies done previously. In the work presented here, we have applied magnetic resonance imaging (MRI)-based CFD to study bladder voiding and to demonstrate the feasibility and potential of this approach. We used 3D dynamic MRI to image the bladder and urethra during voiding. A surface mesh processing tool was developed to process the bladder wall prior to executing a wall-motion driven CFD simulation of the bladder and urethra. The obtained flow rate and pressure were used to calculate urodynamic nomograms, which are currently used in the clinical setting to assess bladder voiding dysfunction. These nomograms concluded that our healthy volunteer has an unobstructed bladder and normal contractility. We calculated the work done to void the bladder and propose this as an additional quantitative metric to comprehensively assess bladder function. Further, we discuss the areas that would improve this relatively new methodology of image-based CFD in urodynamics.

The effect of surgical reconstruction on bladder function in cloacal malformation: A study of urodynamics.

BACKGROUND: Girls with cloacal malformation are at risk of bladder dysfunction, with nearly 90% exhibiting some degree of dysfunction. Surgical dissection, particularly with total urogenital mobilization (TUM), has been hypothesized as a cause of worsening bladder function despite this population commonly having associated vertebral and spinal cord abnormalities that may also explain bladder dysfunction. More recently there has been great effort to select the appropriate surgical technique for cloacal repair in each patient in order to minimize dissection and potential damage to the bladder. We aimed to evaluate the effect of surgical cloacal repair on bladder function based on pre and post-surgery urodynamics (UDS) testing. METHODS: A prospectively collected database of patients with anorectal malformation at a single center was queried for girls with cloacal malformations who had undergone surgical repair from 2015 to 2022. It is our current protocol to perform UDS before and after cloacal repair. Only patients who completed both pre and post-surgery UDS were included. UDS were evaluated and classified using the UMPIRE protocol. RESULTS: A total of 48 patients were included in the cohort. The majority of patients (79.2%) had stable or improved UDS post-op leaving 10 patients (20.8%) who had worsening UDS. Long common channel (≥3 cm) was the only factor significantly associated with worsening UDS. (p = 0.03) Nearly 30% (n = 8) of those undergoing UGS had worse post-op UDS compared to 9.5% (n = 2) with TUM. All patients who worsened UDS initially had safe UDS that changed to intermediate, except for one who worsened to hostile in the setting of significant social challenges and non-compliance. Only common channel length was predictive of worsening UDS, while the type of surgical approach and spine status were not. While the overall risk of worsening UDS after TUM is only 9.5%, patients with normal spines undergoing TUM had the lowest risk, seen in only one in 15 patients (6.6%). CONCLUSIONS: Common channel length was the most significant predictor of worsening UDS, while spine status and surgical technique (TUM vs UGS) did not significantly impact this finding. By following this established surgical protocol based on common channel and urethral lengths, is rare for the surgical cloacal repair to result in worsening post-op UDS, particularly in those undergoing TUM for short common channel and normal spine.

Does Urodynamic Stress Incontinence Increase After the Menopause?: Results from 2,994 Urodynamic Studies in Australian Women.

INTRODUCTION AND HYPOTHESIS: Most studies attempting to estimate the age-related prevalence of urinary incontinence (UI) have used questionnaires. In the present study we analysed a consecutive series of urodynamic test results to determine the distribution of the different types of UI in pre- and post-menopausal women. We hypothesised that the prevalence of urodynamic stress incontinence (USI) would be significantly greater in pre-menopausal than in post-menopausal women. METHODS: All women from a large tertiary urogynaecology department, who underwent urodynamic tests during the years 2000-2015 were included. Patient history and test results were collected. A sample size of 1,475 was calculated, based on the hypothesis that the prevalence of USI will be 20% larger in the pre- versus the post-menopausal group. RESULTS: A total of 2,994 women with UI on urodynamics were available. There was a significant difference between pre- and post-menopausal status for each of the three diagnoses: USI 483 (59.3%) versus 912 (41.8%), detrusor overactivity (DO) 125 (15.4%) versus 399 (18.3%) and USI with concomitant DO 206 (25.3%) versus 869 (39.9%). A bimodal pattern of age was seen in women with USI, with a peak in the 46-50 and 61-65 age group, before decreasing with age. DO generally increased with age. USI with concomitant DO increased steadily after the menopause, becoming the predominant type after the age of 66. CONCLUSIONS: In this large cohort of women attending urodynamics, we have shown that USI is the predominant type of incontinence in pre-menopausal women; however, USI with concomitant DO increases after menopause, eventually predominating.

Strict glucose control and elimination of NLRP3-induced inflammation prevents diabetic bladder dysfunction in the female Akita mouse model.

PURPOSE: Diabetic bladder dysfunction (DBD) is the most common diabetic complication. Logically, regulation of blood glucose should reverse dysfunction, but the Epidemiology of Diabetes Interventions and Complications study found strict control ineffective. However, it is possible that strict control may prevent DBD if initiated before symptoms appear. We examine the effect of early glucose control on development of DBD in the female diabetic Akita mouse (Type 1) and test the potential of inhibiting/deleting NLRP3 as adjunct therapy to glucose control. MATERIALS AND METHODS: Female Akita mice were bred NLRP3+/+ or NLRP3-/-. At 6 weeks of age, diabetics received either no glucose control or insulin pellets (s.c., Linshin) designed to poorly or strictly control blood glucose. At Week 15, blood glucose (glucometer), the extravasation potential of bladder (an indirect measurement of inflammation) and bladder function (urodynamics) were assessed. RESULTS: Blood glucose of diabetics was reduced in poorly controlled and strongly reduced in strictly controlled groups. Levels were not affected by deletion of NLRP3. Evans blue dye extravasation correlated with glucose control and was eliminated in the NLRP3-/- groups. Urodynamics found markers of overactivity in diabetics which was improved in the poorly controlled group and eliminated in the strictly controlled group. In the NLRP3-/- mice, no bladder dysfunction developed, regardless of glucose control. CONCLUSIONS: Early-initiated strict glycemic control and NLRP3 elimination can effectively prevent DBD, suggesting hyperglycemia acts through NLRP3-induced inflammation to trigger DBD.

Validation of the area under the Watts factor curve during the voiding cycle as a novel parameter for diagnosing detrusor underactivity in females.

OBJECTIVE: Detrusor underactivity (DU) is a common cause of lower urinary tract symptoms (LUTS). To date, no consensus has been reached on the urodynamic criteria for defining DU. We previously proposed the area under the curve of the Watts factor (WF-AUC) as a new parameter for diagnosing DU. By comparing previously reported five criteria for DU and WF-AUC, we analyzed whether the WF-AUC could assess detrusor contraction in women with LUTS. METHODS: Using urodynamic data of consecutive 77 women with LUTS, first, we classified DU based on previously reported five criteria. Second, we assessed the potential correlation between multiple parameters and WF-AUC. Third, receiver operating characteristic curve analysis was performed to determine the cutoff value of WF-AUC for diagnosing DU based on previously reported five criteria. Fourth, a linear regression analysis was conducted and compared using multiple criteria and female bladder outlet obstruction index (BOOIf). RESULTS: WF-AUC was positively correlated with the maximum values of WF, bladder contractility index (BCI), and projected isovolumetric pressure 1 (PIP1) with correlation coefficients of 0.63, 0.57, and 0.34, respectively. AUC for diagnosing DU based on previously reported five criteria ranging from 0.773 to 0.896 with different cutoff values of AUC-WF. The Spearman's correlation test revealed that BOOIf was significantly correlated with BCI, but not Wmax, PIP1 and WF-AUC. CONCLUSIONS: This study demonstrated the non-inferiority of the WF-AUC compared to previously reported criteria for defining DU. Depending on the cutoff value, the WF-AUC could appropriately evaluate women with DU, regardless of the presence of BOO.

The Effect of Different Education Methods Before Invasive Urodynamics on Patients' Anxiety, Pain, Readiness and Satisfaction Levels: Randomized Controlled Clinical Trial.

BACKGROUND: Urodynamic testing is an invasive procedure that causes pain and anxiety. Patient education is an evidence-based nursing intervention that relieves pain and anxiety and increases patient satisfaction. AIMS: This study was carried out to compare the effects of different education methods utilized before a urodynamic testing procedure on patients' pain, anxiety, readiness for the procedure, and satisfaction. METHODS: The study is a randomized controlled clinical trial. Participants (n = 80) were randomly assigned to four groups. While patients in the control group were provided with routine clinical information, patients in the intervention group were given education with brochures, videos, and brochure-supported videos. The research data were collected by using a Data Collection Form with items about participants' descriptive characteristics, the Visual Analog Scale, and the State Anxiety Inventory. RESULTS: It was determined that pain expectation before urodynamics and the severity of pain during urodynamics were lower in intervention groups than in the control group. Pain expectation before urodynamics was lower in the brochure-supported video education group than in the brochure education group. Anxiety levels were lower and satisfaction levels were higher in the video education and brochure-supported video education groups than in the control and brochure education groups. CONCLUSIONS: Of the methods utilized, it was determined that the most effective one was brochure-supported video education as it affected all parameters positively.

Early Sacral Neuromodulation Prevented Detrusor Overactivity in Rats With Spinal Cord Injury.

OBJECTIVES: Sacral neuromodulation (SNM) has been shown to alleviate bladder dysfunction in patients with overactive bladder and nonobstructive urinary retention. However, the therapeutic effect and mechanism of SNM in neurogenic bladder dysfunction are still not fully understood. Using a rat model of spinal cord injury (SCI), this study aims to investigate the therapeutic effect of early SNM in the bladder-areflexia phase on neurogenic bladder dysfunction and evaluate its possible mechanism. MATERIALS AND METHODS: Basic physiological parameters such as body/bladder weight, blood pressure, and electrocardiogram results were measured to evaluate the safety of SNM. Enzyme-linked immunosorbent assays and quantitative real-time polymerase chain reaction were used to examine the expression of proinflammatory factors. Hematoxylin and eosin and Masson's trichrome staining were used to observe morphological changes, and cystometry was used to evaluate urodynamic changes after SNM treatment. Western blotting and immunofluorescence staining were used to measure the levels of transient receptor potential vanilloid 1 (TRPV1) and calcitonin gene-related peptide (CGRP) in the L6-S1 dorsal root ganglia (DRGs) and bladder. Capsaicin desensitization was used to investigate whether inhibiting TRPV1 could prevent detrusor overactivity in SCI rats. RESULTS: Early SNM did not affect the body/bladder weight, heart rate, blood pressure, or the expression of proinflammatory cytokines (PGE2, IL-1, IL-2, IL-6, TGF-ß, or TNF-α) in the bladders of SCI rats. Morphologically, early SNM prevented urothelial edema (p = 0.0248) but did not influence collagen/smooth muscle in the bladder. Compared with untreated rats with SCI, the rats treated with SNM exhibited increased bladder capacity (p = 0.0132) and voiding efficiency (p = 0.0179), and decreased nonvoiding contraction (NVC) frequency (p = 0.0240). The maximum pressure, basal pressure, postvoid residual, and NVC amplitude did not change significantly. After the SNM treatment, the expression of TRPV1 in the bladder and CGRP in L6-S1 DRGs weredecreased (L6, p = 0.0160; S1, p = 0.0024) in SCI rats. In capsaicin-desensitized SCI rats, urodynamic results showed an increase in bladder capacity (p = 0.0116) and voiding efficiency (p = 0.0048), and diminished NVC frequency (p = 0.0116), while other parameters did not change significantly. CONCLUSIONS: Early SNM prevented urothelial edema morphologically and detrusor overactivity in SCI rats. Inhibition of TRPV1 in the bladder and DRGs may be one of the potential mechanisms for preventing detrusor overactivity by SNM.

A Comparative Study of Commercially Available Ultrasound Contrast Agents for Sub-harmonic-Aided Pressure Estimation (SHAPE) in a Bladder Phantom.

OBJECTIVE: The goal of this study was to evaluate the performance of different commercial ultrasound contrast microbubbles (MBs) when measuring bladder phantom pressure with sub-harmonic-aided pressure estimation (SHAPE) methodology. We hypothesized that SHAPE performance is dependent on MB formulation. This study aimed to advance the SHAPE application for bladder pressure measurements in humans. METHODS: Using a previously designed and built bladder phantom, we tested four different commercial agents: Definity, Lumason, Sonazoid and Optison. A standard clinical cystometrogram (CMG) system was used to infuse a MB-saline mixture into the bladder phantom to measure pressure. Ultrasound imaging was performed using the GE Healthcare LOGIQ E10 scanner. RESULTS: All agents showed a predicted inverse linear relationship between change in pressure and SHAPE signal. However, they differ from each other in terms of stability, linear correlation, sensitivity to pressure and error. Generally, Definity and Lumason showed the highest performance during the SHAPE-based bladder phantom pressure assessments. CONCLUSION: Our results show that the SHAPE signal decreases as bladder phantom pressures increases, regardless of the agent or CMG phase, suggesting the possibility of using SHAPE for measuring bladder pressure without a catheter. However, the efficacy of SHAPE in measuring pressure varies by MB formulation. These observations support using Lumason and Definity in a human subject feasibility study as we advance toward a catheter-free solution for measuring voiding bladder pressure via SHAPE.

Risk factors of video urodynamics and bladder management for long-term complications in patients with chronic spinal cord injury.

This study explores 15-year urological complications in chronic spinal cord injury (SCI) patients and investigates the predictive factors from video-urodynamic study (VUDS) and bladder management. Analyzing 864 SCI patients with a mean 15.6-year follow-up, we assessed complications and utilized multivariate logistic regression for risk evaluation. VUDS factors such as autonomic dysreflexia, detrusor sphincter dyssynergia, vesicourethral reflux (VUR), contracted bladder, and high voiding detrusor pressure significantly increased the likelihood of recurrent urinary tract infections (rUTI). Low bladder compliance, VUR, and contracted bladder notably raised the risk of hydronephrosis, while contracted bladder and detrusor overactivity with detrusor underactivity heightened chronic kidney disease risk. Volitional voiding reduced rUTI and VUR risk, whereas Valsalva maneuver-assisted voiding increased hydronephrosis risk. In conclusion, a contracted bladder identified in VUDS is associated with long-term urological complications in SCI, we propose that patients already experiencing a contracted bladder should prioritize volitional voiding as their preferred bladder management strategy to minimize the risk of additional complications such as rUTI and VUR. These findings unveil previously unexplored aspects in research, emphasizing the need for proactive management strategies in this patient population.

Can Videourodynamics shape management in refractory pediatric lower urinary tract dysfunction?

INTRODUCTION: Bladder dysfunction, or more specifically lower urinary tract dysfunction (LUTD), remains a common reason for pediatric urology consultation, and the management of these patients is time consuming and frustrating for patients, families and providers alike. But what happens when the patient proves refractory to current treatment modalities? Is there a role for the use of videourodynamics (VUDS) to help guide therapy in the patient with refractory voiding dysfunction, and if so how might we select patients for this invasive study in order to increase the yield of useful information? OBJECTIVES: To determine the role, if any, for VUDS in the evaluation of pediatric patients with refractory LUTD and to identify parameters that might be used to select patients for this invasive study in order to increase the yield of useful information. STUDY DESIGN: Through our IRB-approved prospectively maintained urodynamics database, we retrospectively identified 110 patients with non-neurogenic LUTD over a period from 2015 to 2022 who underwent VUDS. We excluded patients with known neurologic or anatomic lesions and developmental delay. RESULTS: There were 76 females and 34 males (69%/31%) and their average age at the time of the study was 10.5 years ± 4 with a median age of 7.3 years. Patients had been followed for a mean of 5.9 ± 3.5 office visits prior to obtaining the VUDS and reported a mean Dysfunction Voiding and Incontinence Symptom Score (DVISS) of 15.6 ± 6.7 before the VUDS. VUDS resulted in a change in management in 86 of these 110 patients (78%). Management changes included a change in medication (53/110), consideration of CIC (11/110), PTENS (1/110) and surgery (14/110). As shown in the Figure, the DVISS score was significantly higher and the number of office visits prior to VUDS was significantly higher in the 86 patients whose management was changed versus the 24 patients in whom management did not change (P < 0.02). CONCLUSION: This retrospective analysis suggests that criteria for selecting these patients include: 1) long standing urinary incontinence that is refractory to biofeedback and medications, 2) ≥6 visits to LUTD clinic with no improvement, and 3) LUT symptom score of ≥16. Our findings suggest these criteria identify a cohort of patients in which a VUDS evaluation for the child with refractory LUTD can offer a more exact diagnosis that can shape management.

Constrictive versus compressive bladder outflow obstruction in men: Does it matter?

INTRODUCTION: Bladder outflow obstruction (BOO) is a urethral resistance (UR) at a level above a clinically relevant threshold. UR is currently graded in terms of the existence and severity of the BOO based on maximum flowrate and associated detrusor pressure only. However, the pressure-flow relation throughout the course of voiding includes additional information that may be relevant to identify the type of BOO. This study introduces a new method for the distinction between the provisionally called compressive and constrictive types of BOO and relates this classification to underlying patient and urodynamic differences between those BOO types. METHODS: In total, 593 high-quality urodynamic pressure-flow studies in men were included in this study. Constrictive BOO was identified if the difference Δp between the actual minimal urethral opening pressure (pmuo) and the expected pmuo according to the linearized passive urethral resistance relation (linPURR) nomogram was >25 cmH2O. Compressive BOO is identified in the complementary case where the pressure difference Δp ≤ 25 cmH2O. Differences in urodynamic parameters, patient age, and prostate size were explored. RESULTS: In 81 (13.7%) of the cases, constrictive BOO was found. In these patients, the prostate size was significantly smaller when compared to patients diagnosed with compressive BOO, while displaying a significantly lower maximum flowrate, higher detrusor pressure at maximal flowrate and more postvoid residual (PVR). CONCLUSION: This study is an initial step in the validation of additional subtyping of BOO. We found significant differences in prostate size, severity of BOO, and PVR, between patients with compressive and constrictive BOO. Subtyping of voiding-outflow dynamics may lead to more individualized management in patients with BOO.

Applications of machine learning in urodynamics: A narrative review.

BACKGROUND: Machine learning algorithms as a research tool, including traditional machine learning and deep learning, are increasingly applied to the field of urodynamics. However, no studies have evaluated how to select appropriate algorithm models for different urodynamic research tasks. METHODS: We undertook a narrative review evaluating how the published literature reports the applications of machine learning in urodynamics. We searched PubMed up to December 2023, limited to the English language. We selected the following search terms: artificial intelligence, machine learning, deep learning, urodynamics, and lower urinary tract symptoms. We identified three domains for assessment in advance of commencing the review. These were the applications of urodynamic studies examination, applications of diagnoses of dysfunction related to urodynamics, and applications of prognosis prediction. RESULTS: The machine learning algorithm applied in the field of urodynamics can be mainly divided into three aspects, which are urodynamic examination, diagnosis of urinary tract dysfunction and prediction of the efficacy of various treatment methods. Most of these studies were single-center retrospective studies, lacking external validation, requiring further validation of model generalization ability, and insufficient sample size. The relevant research in this field is still in the preliminary exploration stage; there are few high-quality multi-center clinical studies, and the performance of various models still needs to be further optimized, and there is still a distance from clinical application. CONCLUSIONS: At present, there is no research to summarize and analyze the machine learning algorithms applied in the field of urodynamics. The purpose of this review is to summarize and classify the machine learning algorithms applied in this field and to guide researchers to select the appropriate algorithm model for different task requirements to achieve the best results.

Appearance of the bladder on initial voiding cystogram in boys with PUV and its relation to pre and postnatal findings.

Introduction: Bladder profile in boys with Posterior Urethral Valves can be very varied with a spectrum going from high pressure, unstable, hypocompliant small bladders to hypercompliant, large acontractile bladders, with some being near-normal. Our question was whether appearance, specifically of the bladder, on initial VCUG was correlated to prenatal features and whether it could predict early postnatal outcome. Method: We used a prospectively gathered database of boys with prenatally suspected PUV. We analyzed whether the appearance, specifically of the bladder, was related to date of prenatal diagnosis, presence of a megacystis on prenatal ultrasound, presence of vesico-ureteral reflux (VUR), presence of abnormal DMSA scan, nadir creatinine or presence of febrile urinary tract infection (fUTI) during the first two years of life. Results: The database comprised 90 cystograms. 15% of bladders were judged normal/regular, 54 % were small/diverticular and 31% were large/diverticular. Bladder appearance was not associated with presence of prenatal megacystis, abnormal DMSA scan, VUR, nor rate of fUTI. The only significant associations were normal/regular bladder and early prenatal diagnosis (p = 0.04) and normal/regular bladder and elevated nadir creatinine (>75µmol/l) (p = 0.01). Discussion: We believe that when focusing solely on the appearance of the bladder, excluding information about the urethra and presence of reflux, the cystogram alone is insufficient to inform on future bladder function. This could be used as an argument in favor of performing early urodynamics in this population.