An automatic diagnostic system for the urodynamic study applying in lower urinary tract dysfunction

OBJECTIVE

To establish an automatic diagnostic system based on machine learning for preliminarily analysis of urodynamic study applying in lower urinary tract dysfunction (LUTD).

METHODS

The eight most common conditions of LUTDs were included in the present study. A total of 527 eligible patients with complete data, from the year of 2015 to 2020, were enrolled in this study. In total, two global parameters (patients' age and sex) and 13 urodynamic parameters were considered to be the input for machine learning algorithms. Three machine learning approaches were applied and evaluated in this study, including Decision Tree (DT), Logistic Regression (LR), and Support Vector Machine (SVM).

RESULTS

By applying machine learning algorithms into the 8 common LUTDs, the DT models achieved the AUC of 0.63-0.98, the LR models achieved the AUC of 0.73-0.99, and the SVM models achieved the AUC of 0.64-1.00. For mutually exclusive diagnoses of underactive detrusor and acontractile detrusor, we developed a classification model that classifies the patients into either of these two diseases or double-negative class. For this classification method, the DT models achieved the AUC of 0.82-0.85 and the SVM models achieved the AUC of 0.86-0.90. Among all these models, the LR and the SVM models showed better performance. The best model of these diagnostic tasks achieved an average AUC of 0.90 (0.90 ± 0.08).

CONCLUSIONS

An automatic diagnostic system was developed using three machine learning models in urodynamic studies. This automated machine learning process could lead to promising assistance and enhancements of diagnosis and provide more useful reference for LUTD treatment.

Screening for Zinner Syndrome in Patients With a Congenitally Solitary Kidney: Lessons Learned

PURPOSE

We determined if serial screening ultrasounds are beneficial in evaluating for the development of Zinner syndrome in males with a congenital solitary kidney.

MATERIALS AND METHODS

All patients included had their congenital solitary kidney diagnosed at <20 years of age and had to be ≥20 at their last visit. Individuals were seen annually, with pelvic ultrasounds to screen for mesonephric duct cysts obtained at birth and every year of age, divisible by 5.

RESULTS

At a median follow-up of 38 years of age (range 20-57), 17% (20/121) developed Zinner syndrome, with 60% (12/20) developing clinical symptoms. The yield for screening ultrasound studies was significantly higher in patients ≤20 years of age at 3.5% (12/340), compared to 0.33% (1/296) in patients >20 years of age (P = .004). Serial ultrasounds reveal the onset of lower urinary tract and cyst-related pain symptoms are associated with the growth of the seminal vesicle cyst to ≥5 cm (P = .0198). Of symptomatic patients, 75% (8/12) had abnormal uroflows. Complete urodynamic studies revealed findings consistent with bladder outlet obstruction in 38% (3/8), equivocal for obstruction in 24% (2/8), and detrusor underactivity in 38% (3/8). Cyst excision effectively resolved voiding symptoms that were obstructive in etiology but failed to resolve symptoms in patients with detrusor underactivity.

CONCLUSIONS

Serial ultrasound evaluations reveal that cyst growth to ≥5 cm in size is highly related to the onset of clinical symptoms, with the resolution of voiding symptoms by cyst excision directly associated with urodynamic findings.

Transcriptomics Reveals Molecular Features of the Bilateral Pelvic Nerve Injury Rat Model of Detrusor Underactivity

The pathogenesis of detrusor underactivity (DU) is unclear, and the available therapeutic effects are unsatisfactory. We propose to find key molecules and pathways related to DU based on transcriptome sequencing. A rat model of bilateral pelvic nerve injury (BPNI) was established. Bladder tissues from the sham-operated group, 3 and 28 days after BPNI mapping, were taken for urodynamics, histopathology, and RNA-seq. An enrichment analysis of the screened differential expression genes was performed. Three days after BPNI, the results showed urodynamic features of overflow incontinence, while there was a recovery at 28 days after the operation. Masson staining revealed collagen deposition accompanied by progressive thickening of the smooth muscle layer as DU progressed. RNA-seq results suggested that a total of 1808 differentially expressed genes (DEGs) differed among the groups. RNA-seq and subsequent analysis confirmed that the cell cycle and immune response were significantly activated 3 days after BPNI, while extracellular matrix remodeling occurred 28 days after BPNI. Partial DEGs and pathways were verified by qRT-PCR. Validation of key proteins involved in cell cycle, inflammation, and fibrosis was performed by immunohistochemical staining and western blot, respectively. These molecular expression patterns at different time points after BPNI injury provide valuable insights into the search for therapeutic targets for DU.

Detrusor underactivity is associated with metabolic syndrome in aged primates

Lower urinary tract (LUT) dysfunction is prevalent in the elderly population, and clinical manifestations include urinary retention, incontinence, and recurrent urinary tract infections. Age-associated LUT dysfunction is responsible for significant morbidity, compromised quality of life, and rising healthcare costs in older adults, but its pathophysiology is not well understood. We aimed to investigate the effects of aging on LUT function by urodynamic studies and metabolic markers in non-human primates. Adult (n = 27) and aged (n = 20) female rhesus macaques were evaluated by urodynamic and metabolic studies. Cystometry showed detrusor underactivity (DU) with increased bladder capacity and compliance in aged subjects. Metabolic syndrome indicators were present in the aged subjects, including increased weight, triglycerides, lactate dehydrogenase (LDH), alanine aminotransferase (ALT), and high sensitivity C-reactive protein (hsCRP), whereas aspartate aminotransferase (AST) was unaffected and the AST/ALT ratio reduced. Principal component analysis and paired correlations showed a strong association between DU and metabolic syndrome markers in aged primates with DU but not in aged primates without DU. The findings were unaffected by prior pregnancies, parity, and menopause. Our findings provide insights into possible mechanisms for age-associated DU and may guide new strategies to prevent and treat LUT dysfunction in older adults.

Loss of resilience contributes to detrusor underactivity in advanced age

Volume hyposensitivity resulting from impaired sympathetic detrusor relaxation during bladder filling contributes to detrusor underactivity (DU) associated with aging. Detrusor tension regulation provides an adaptive sensory input of bladder volume to the brainstem and is challenged by physiological stressors superimposed upon biological aging. We recently showed that HCN channels have a stabilizing role in detrusor sympathetic relaxation. While mature mice maintain homeostasis in the face of stressors, old mice are not always capable. In old mice, there is a dichotomous phenotype, in which resilient mice adapt and maintain homeostasis, while non-resilient mice fail to maintain physiologic homeostasis. In this DU model, we used cystometry as a stressor to categorize mice as old-responders (old-R, develop a filling/voiding cycle) or old-non-responders (old-NR, fail to develop a filling/voiding cycle; fluctuating high pressures and continuous leaking), while also assessing functional and molecular differences. Lamotrigine (HCN activator)-induced bladder relaxation is diminished in old-NR mice following HCN-blockade. Relaxation responses to NS 1619 were reduced in old-NR mice, with the effect lost following HCN-blockade. However, RNA-sequencing revealed no differences in HCN gene expression and electrophysiology studies showed similar percentage of detrusor myocytes expressing HCN (I_h) current between old-R and old-NR mice. Our murine model of DU further defines a role for HCN, with failure of adaptive recalibration of HCN participation and intensity of HCN-mediated stabilization, while genomic studies show upregulated myofibroblast and fibrosis pathways and downregulated neurotransmitter-degradation pathways in old-NR mice. Thus, the DU phenotype is multifactorial and represents the accumulation of age-associated loss in homeostatic mechanisms.

Myogenic Underactive Bladder and Heart Failure Resemblance: A Novel Role for SGLT2 Inhibition?

The heart and bladder share physiological biomechanical determinants of contraction. Heart failure (HF) and myogenic underactive bladder (mUAB) also share similarities in their pathophysiology. In both cases there is muscle injury that is directly linked to disease stage. In the final stage, both myocardium and detrusor show marked fibrosis and lower contractility. While HF has an established pharmacological treatment, there are still no effective drugs for mUAB. This mini-review explores the similarities between HF and mUAB and suggests that, as in HF, SGLT2 inhibitors may also have a beneficial role in mUAB. PATIENT SUMMARY: To date, there is no treatment for underactive bladder caused by problems with the bladder muscle (mUAB). We review similarities between this condition and heart failure and hypothesize that a recent drug class with striking results in heart failure might also have a beneficial role in mUAB.

Ossabaw Pig Demonstrates Detrusor Fibrosis and Detrusor Underactivity Associated with Oxidative Stress in Metabolic Syndrome

Metabolic Syndrome (MetS) has detrimental effects on the bladder, including detrusor underactivity. The progression and mechanism of disease are poorly understood. A swine model for diabetic bladder dysfunction (DBD) was established because of the pig's human-sized bladder and its ability to develop MetS by dietary modification alone. The hypothesis of this study is that this swine model will demonstrate oxidative stress associated with MetS, which contributes to both bladder fibrosis and detrusor underactivity (DU). Ossabaw pigs underwent dietary modification consisting of a hypercaloric, atherogenic diet for 10 mo to induce MetS, and were compared with a group of control (lean) pigs. Urodynamic studies were performed in both groups to confirm DU. Thiobarbituric acid reactive substances (TBARS) detected in the urine were used to measure oxidative stress activity in the urinary tract, and urinary IL17a was used to detect profibrotic activity. MetS was confirmed by assessing body weight, blood pressure, glucose tolerance, total cholesterol, and triglycerides. The MetS group exhibited an increase in the relative levels of urinary TBARS and IL17a. Bladder pressures at capacity were lower in the MetS group, suggesting DU. Histologic analysis of a cohort of control (lean) and MetS pigs revealed that as compared with the control pigs, the MetS pigs had significantly more collagen in the muscularis layer, but not in the submucosa or mucosa layer. In conclusion, the Ossabaw pig model for diet-induced MetS is associated with oxidative stress and profibrotic activity in the bladder, which results in DU. This has previously been shown in mice and rats, but never in pigs. This novel model will better represent human MetS and DBD because the mechanism and size of the pig bladder more closely resemble that of a human, resulting in a more valid model and facilitating further study into the signaling mechanisms responsible for this impairment.

[Functional changes during the voiding phase in males with non-neurogenic detrusor underactivity undergoing bladder catheterization.]

OBJECTIVES

To investigate urodynamic changes during the voiding phase in males with detrusor underactivity (DU) undergoing bladder catheterization for urinary retention.

METHODS

From a total of 64 patients with urinary retention, a follow-up study was performed in 17 males with a mean age of 77 years. Patients received a urodynamic diagnosis of DU based on a Bladder Contractility Index (BCI) score of < 100 and underwent permanent bladder catheterization (16 cases) or clean intermittent catheterization (1 case) for acute urinary retention (14 cases), or post void residual urine (3 cases). Patients underwent a second urodynamic study after a mean 13 months of follow-up. Fisher's exact test was used with categorical variables and Student's t test with parametric variables. The level of significance was set at p < 0.05 for a two-sided test.

RESULTS

The second urodynamic study showed a significant increase in maximal detrusor pressure, pressure at maximum flow rate, BCI score, Bladder Outlet Obstruction Index (BOOI) score, and number of patients who urinated during the pressure-flow study.

CONCLUSIONS

Bladder catheterization in men with DU significantly improves bladder contractility and revealed obstructions of the lower urinary tract that were masked by insufficient detrusor pressure in relation to the DU of these patients. These findings could have diagnostic as well as prognostic and therapeutic applications.

[Sacral neuromodulation in under- and overactive detrusor-quo vadis? : Principles and developments]

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.