Lower urinary tract dysfunction in pediatrics progress to kidney disease in adolescents: Toward precision medicine in treatment

Pediatric Lower Urinary Tract Dysfunction: A Comprehensive Exploration of Clinical Implications and Diagnostic Strategies

Lower urinary tract dysfunction is clinically important because it may cause urinary tract infections, mainly due to accumulation of residual urine, and adversely affect renal function. In addition, it may cause urinary incontinence, strongly affecting the child's quality of life. The function of the lower urinary tract is closely associated with function of the bowel because constipation is commonly present with bladder dysfunction. The interplay between the lower urinary tract and bowel function, coupled with common conditions such as detrusor overactivity and voiding dysfunction, requires a nuanced diagnostic approach. Detrusor overactivity, a benign but socially harmful condition, is the principal cause of daytime urinary incontinence in childhood. It needs to be differentiated from more serious conditions such as neurogenic bladder dysfunction or urethral obstruction. Voiding dysfunction, a habitual sphincter contraction during voiding, is common in children with detrusor overactivity and may be self limiting but may also result in residual urine and urinary tract infections. It may resemble, in severe cases, neurogenic bladder dysfunction, most often caused by spinal dysraphism, which very often leads to recurrent urinary tract infections and high intravesical pressures, jeopardizing renal function. A voiding diary is crucial in the initial evaluation of lower urinary tract function in children.

Substantial incidence of bladder dysfunction in patients with VACTERL association: Implications for surveillance

VACTERL association is defined as the nonrandom co-occurrence of a minimum of three of the following six key components: Vertebral anomalies, Anal atresia, Cardiac malformations, Tracheo-Esophageal fistula, Renal anomalies, and Limb abnormalities. Patients presenting with two components may also belong in the same spectrum. Additional components have been associated with VACTERL defects, including single umbilical artery, tethered spinal cord (TSC), and genital malformations. We observed a significant proportion of patients with bladder dysfunction (often called neurogenic bladder in the medical record) when reviewing a cohort of patients with VACTERL defects at our clinical center. Our finding calls attention to bladder dysfunction as an additional VACTERL phenotypic component. The prevalence of bladder dysfunction is greatest in those with genital anomalies, anorectal malformations, sacral dysplasia, renal anomalies, and TSC. We propose that patients with two or more VACTERL malformations be monitored for symptoms of bladder dysfunction if one or more of the identified risk factors are present until the achievement of urinary continence.

Is bladder outlet obstruction rat model to induce overactive bladder (OAB) has similarity to human OAB? Research on the events in smooth muscle, collagen, interstitial cell and telocyte distribution

BACKGROUND

Cellular and cytoskeletal events of overactive bladder (OAB) have not been sufficiently explored in human bladder due to different limitations. Bladder outlet obstruction (BOO) had been induced in different animal models with different methods to induce (OAB). Similarity of the animal models of BOO to the human OAB is postulated but has not been confirmed. The interstitial cells of Cajal (ICCs), and telocytes (TCs) are an important players in smooth muscles conductivity, they had not been well investigated in the previous BOO models. Objectives are to investigate the morphological pattern of cellular, cytoskeleton and telocytes distribution in BOO rat model and to match the events in two time periods and compare it to the findings in real-world human OAB.

METHODS

Female Sprague-Dawley rats (Rattus norvegicus) were randomly divided into: sham (n = 10), BOO 6 W (n = 10), BOO 8 W (n = 10). Operative procedure to Induce BOO was done under anesthesia with intraperitoneal Ketamine administration. The Effect of induction of BOO was evaluated after 6 and 8 weeks. The rats were anesthetized, and the urinary bladder was removed, while the rat was unconscious under anaesthesia it was transferred to the inhalation anaesthesia cage for euthanasia, rats were sacrificed under light anesthesia using isoflurane. Care of animals, surgical procedure, and euthanasia adhered to Guide for the Care and Use of Laboratory Animals, and AVMA Guidelines for the Euthanasia of Animals. The retrieved bladder was processed for examination with histopathology, immunohistochemistry (IHC), and transmission electron microscopy (EM).

RESULTS

Histological examination of the bladder shows thinner urothelium, condensation of collagen between muscle bundles. IHC with c-kit shows the excess distribution of ICCs between smooth muscle bundles. EM shows frequent distribution of TCs that were situated between collagen fibers. Finings in BOO 6 W group and BOO 8 W group were comparable.

CONCLUSION

The animal model study demonstrated increased collagen/ smooth muscle ratio, high intensity of ICCs and presence of TCs. Findings show that a minimally invasive procedure to induce BOO in rats had resulted in an OAB that has morphological changes that were stable in 6 & 8 weeks. We demonstrated the distribution of TCs and ICCs in the rat animal model and defined them. The population of TCs in the BOO rat model is described for the first time, suggests that the TCs and ICCs may contribute to the pathophysiology of OAB. Similarity of animal model to human events OAB was demonstrated. These findings warrant further study to define the role of TCs in OAB.

CLINICAL TRIAL REGISTRY

The study does not require a clinical trial registration; it is an experimental animal study in basic science and does not include human subjects.

Association of Renal Function (Estimate Glomerular Filtration Rate) with the Number of Febrile Urinary Tract Infections in Children with Neurogenic Bladder

INTRODUCTION

 Our objective was to evaluate whether renal function, assessed as the estimated glomerular filtration rate (eGFR), is associated with the number of febrile urinary tract infections (FUTIs) in children diagnosed with neurogenic bladder (NB).

MATERIALS AND METHODS

 Clinical information of patients diagnosed with NB was prospectively collected between January 2013 and January 2022. Episodes of FUTI were recorded during the follow-up period, and the eGFR was calculated based on the serum cystatin C level. Grading (G1-G5) of chronic kidney disease (CKD) was conducted as described by the eGFR.

RESULTS

 In total, 463 children were included in the final analysis (265 males and 198 females; mean age: 23 months). The median follow-up time was 51 months. A total of 302 children had four or more FUTIs and 161 children had none to three FUTIs. The incidence of developing CKD G3 to G5 gradually increased from the first to third (1.3-2.4%) episodes of FUTI and drastically increased after four episodes (≥ 22.5%), with the incidence recorded to be 100% after eight FUTIs. The odds of CKD G3 to G5 in children with four FUTIs were 17.3 and 43.7 times greater after four and six FUTIs, respectively, than in children with one FUTI.

CONCLUSION

 This study showed that recurrent FUTIs are common in children with NB and that the risk of rapid progression to CKD G3 to G5 increases substantially after four or more FUTIs episodes.

Risk factors associated with recurrent febrile urinary tract infection in children with neurogenic bladder who perform clean intermittent catheterization

OBJECTIVE

To identify the clinical and urodynamic risk factors associated with the development of recurrent febrile urinary tract infections (FUTIs) in children with neurogenic bladder (NB) who perform clean intermittent catheterization (CIC).

METHODS

Children with NB receiving CIC were prospectively enrolled from January to December 2019 and followed up prospectively for 2 years. All data were compared between occasional (0-1 FUTI) and recurrent FUTIs (≥2 FUTI) groups. In addition, the risk factors for recurrent FUTIs in children were evaluated.

RESULTS

Complete data from 321 children were analyzed. Occasional FUTIs occurred in 223 patients, and 98 patients experienced recurrent FUTIs. Univariate and multivariate analyses, showed late-initiation and low-frequency CIC, vesicoureteral reflux (VUR), small bladder capacity and low compliance, and detrusor overactivity were associated with an increased risk of recurrent FUTIs. Children with high-grade VUR (grades IV-V) had a higher risk of recurrent FUTIs than those with low-grade VUR (grades I-III) (odds ratio [OR]: 26.95 vs. OR: 4.78, p < 0.001).

CONCLUSIONS

Our study suggests that late-initiation and low-frequency CIC, VUR, small bladder capacity and low compliance, and detrusor overactivity were associated with recurrent FUTIs in patients with NB. In addition, high-grade VUR is a crucial risk factor for recurrent FUTIs.

Improved contractile potential in detrusor microtissues from pediatric patients with end stage lower urinary tract dysfunction

Autologous cell-based tissue engineering has been proposed as a treatment option for end stage lower urinary tract dysfunction (ESLUTD). However, it is generally accepted that cells isolated from patient bladders retain the pathological properties of their tissue of origin and therefore need to be improved before they can serve as a cell source for tissue engineering applications. We hypothesize that human three-dimensional (3D) microtissues of detrusor smooth muscle cells (SMCs) are valuable ex vivo disease models and potent building blocks for bladder tissue engineering. Detrusor SMCs isolated from bladder wall biopsies of pediatric ESLUTD patients and healthy controls were expanded and cultured into 3D microtissues. Gene and protein analyses were performed to explore the effect of microtissue formation on SMC viability, contractile potential, bladder wall specific extracellular matrix (ECM) composition and mediators of ECM remodeling. Through microtissue formation, remodeling and intensified cell-cell interactions, the ESLUTD SMCs lost their characteristic disease phenotype. These microtissues exhibited similar patterns of smooth muscle related contractile proteins and essential bladder wall-specific ECM components as microtissues from healthy control subjects. Thus, the presented data suggest improved contractile potential and ECM composition in detrusor SMC microtissues from pediatric ESLUTD patients. These findings are of great relevance, as 3D detrusor SMC microtissues might be an appropriate cell source for autologous cell-based bladder tissue engineering.