Posterior urethral valves: renal failure and prenatal treatment

Renal-Protective Urinoma Formation in a Newborn Boy With Posterior Urethral Valves

Posterior urethral valves (PUV) are an uncommon urologic congenital anomaly in males often discovered antenatally and more rarely after birth. PUV can lead to obstructive nephropathy and voiding dysfunction, putting patients at increased risk for irreversible renal damage and subsequent progression to end-stage renal disease. Much of the renal damage caused by PUV is proportional to the amount of time that the kidney has been experiencing retrograde pressure. Although much debate exists within the field, spontaneous decompression within the collecting system (e.g., "pop-off" valve) such as urinoma formation or spontaneous ascites has been found to relieve pressure on and thus protect the kidney, decreasing the risk of progression to advanced stages of chronic kidney disease. Despite the significant mass effect on the renal parenchyma, the pressure-relieving function of urinoma formation is a net protective factor allowing renal function to be preserved. We report a unique case of antenatal detection of PUV in a male with postnatal complicated urinoma formation secondary to forniceal rupture. Remarkably, despite significant external compression of the kidney and the development of urosepsis from infection of the urinoma with a multidrug-resistant organism that required percutaneous drainage, renal function was preserved throughout the disease course. After ablation of the PUV and drainage of the septic urinoma, the patient recovered rapidly after intervention and was ultimately discharged in stable condition.

From Clinical Scenarios to the Management of Lower Urinary Tract Symptoms in Children: A Focus for the General Pediatrician

Lower urinary tract symptoms (LUTS) are a relevant problem in the pediatric population, having a very high prevalence. Diurnal incontinence and nocturnal enuresis are surely the most frequent symptoms, presenting, respectively, in up to 30% of school-age children and up to 10% of children between 6 and 7 years. Stypsis is the most common comorbidity, and it must be considered in the management of LUTS; indeed, the treatment of constipation is curative in most cases for both incontinence and enuresis. The presence or absence of diurnal symptoms in nocturnal enuresis and urgency in diurnal incontinence helps in the differential diagnosis. Urotherapy is always the first-line treatment, while oxybutynin and desmopressin (where appropriate) may help if the first-line treatment is unsuccessful. It is essential to identify conditions that are potentially dangerous for kidney and urinary tract well-being, for which LUTS can be the first manifestation. Starting from a series of clinical scenarios, we will underline the diagnostic clues behind LUTS in children and we will summarize clinical and surgical approaches for the proper management of these conditions.

Evaluation of polyuria and polydipsia along with other established prognostic factors in posterior urethral valves for progression to kidney failure: experience from a developing country

BACKGROUND

Up to 50% of children with posterior urethral valves (PUV) progress to kidney failure. This study aimed to evaluate polyuria and polydipsia and other established variables with later development of kidney failure in children with PUV.

METHODS

Retrospective analysis of 297 children with PUV who underwent ablation of valves between January 1992 and January 2015 at our tertiary care center. Patients were divided into two groups: those who developed kidney failure (group 1) and those who did not (group 2). Specific prognostic factors for progression to kidney failure were analyzed including age at presentation < 1 year, nadir serum creatinine > 1.0 mg/dl, bilateral grade 3 or higher VUR at diagnosis, recurrent febrile UTIs, severe bladder dysfunction, polyuria, and polydipsia.

RESULTS

Thirty-eight (12.8%) patients progressed to kidney failure. Twenty-four and 64 patients were polyuric in group 1 and group 2 respectively (p < 0.001, Z-4.4666). Twenty-two and 61 patients were polydipsic in both groups respectively (p < 0.001). On univariate analysis, predicting variables were as follows: age at presentation < 1 year (p < 0.001), nadir serum creatinine > 1 mg/dl (p < 0.001), B/L high-grade VUR (p < 0.001), severe bladder dysfunction (p < 0.001), recurrent febrile UTIs (p = 0.002), polyuria (p < 0.001), and polydipsia (p < 0.001). On multivariate Cox regression analysis, severe bladder dysfunction, recurrent febrile UTIs, polyuria, and polydipsia were identified as significant prognostic factors predictive of ultimate progression to kidney failure.

CONCLUSION

Polyuria and polydipsia along with recurrent febrile UTI and bladder dysfunction are major prognostic factors affecting long-term kidney outcome in cases of PUV. Graphical abstract.

Neurophysiological control of urinary bladder storage and voiding-functional changes through development and pathology

The effective storage of urine and its expulsion relies upon the coordinated activity of parasympathetic, sympathetic, and somatic innervations to the lower urinary tract (LUT). At birth, all mammalian neonates lack the ability to voluntary regulate bladder storage or voiding. The ability to control urinary bladder activity is established as connections to the central nervous system (CNS) form through development. The neural regulation of the LUT has been predominantly investigated in adult animal models where comparatively less is known about the neonatal and postnatal neurophysiological development that facilitate urinary continence. Furthermore, congenital neurological or anatomical defects can adversely affect both storage and voiding functions through postnatal development and into adulthood, leading to secondary conditions including vesicoureteral reflux, chronic urinary tract infections, and end-stage renal disease. Therefore, the aim of the review is to provide the current knowledge available on neurophysiological regulation of the LUT through pre- to postnatal development of human and animal models and the consequences of congenital anomalies that can affect LUT neural function.

Renal outcome among children with posterior urethral valve: When to worry?

INTRODUCTION

Posterior urethral valve (PUV) is a congenital obstructive defect of male urethra that is diagnosed early during antenatal period with a presence of hydroureteronephrosis and associated with several morbidities including chronic kidney disease (CKD) that requires management, therefore, this study aim to evaluate the renal outcome of endoscopic valve ablation and urinary tract diversion in children with PUV, "when to worry, and what to do."

METHODOLOGY

This is a retrospective cohort study reviewing medical records of all patients diagnosed with PUV that has been managed in Pediatric Urology Unit at King Abdul-Aziz Medical City, Jeddah in the period of 1998-2008 with proven diagnosis at age younger than 16 accounted for 39 patients, and with different multiple demographics such as antenatal and postnatal ultrasound findings, serum levels of preoperative creatinine, mode of surgical treatment (i.e., endoscopic valve ablation and urinary diversions). Patients were divided into two groups according to the initial surgical intervention. Patient's characteristics and other variables were analyzed; t-test and Chi-square test were used.

RESULTS

During the follow-up period, (45%) developed CKD with a mean time of 5.5 years, 18% reach to end stage renal disease (ESRD), (10%) requiring dialysis. Abnormal creatinine level was detected in 69% (27/39) of our patients before the intervention and normalized in 97% after intervention. In comparison between the two intervention groups, CKD were developed in 60% of patients with urinary diversion in comparison to 33% for the endoscopic ablation group with no statistical significance with P = 0.09. The time to develop CKD was faster in the diversion group with mean age of 18 months (standard deviation [SD] 2 years) in comparison to endoscopic ablation group with mean age 6 years (SD 4 years). Similar results were observed for development of ESRD, patients who underwent diversion had slightly higher incidence of ESRD. In our cohort group, the main determinant for deterioration of the future kidney function was the level of serum creatinine, preoperatively. Moreover, recurrent urinary tract infections (UTIs) were developed in 64% of our cohort group and 49% of our population diagnosed with voiding dysfunction at 6 years of age.

CONCLUSION

A child with PUV who has a risk factor does have an increased potential of developing CKD, knowing that the type of intervention offered to treat PUV has no impact on the outcome. Furthermore, not having any of the study mentioned risk factors doesn't rule out the possibility of developing comorbidities which suggest that any child with PUV always need to be worried about and longer follow-up is indicated. Early intervention, check cystoscopy after ablation, close follow-up with appropriate laboratory and radiological investigation when necessary are recommended, and to improve the quality of data to the level reaching to a meaningful conclusion with high accuracy, a national database system from all centers across the country should be implemented.

The ANTENATAL multicentre study to predict postnatal renal outcome in fetuses with posterior urethral valves: objectives and design

Background

Posterior urethral valves (PUV) account for 17% of paediatric end-stage renal disease. A major issue in the management of PUV is prenatal prediction of postnatal renal function. Fetal ultrasound and fetal urine biochemistry are currently employed for this prediction, but clearly lack precision. We previously developed a fetal urine peptide signature that predicted in utero with high precision postnatal renal function in fetuses with PUV. We describe here the objectives and design of the prospective international multicentre ANTENATAL (multicentre validation of a fetal urine peptidome-based classifier to predict postnatal renal function in posterior urethral valves) study, set up to validate this fetal urine peptide signature.

Methods

Participants will be PUV pregnancies enrolled from 2017 to 2021 and followed up until 2023 in >30 European centres endorsed and supported by European reference networks for rare urological disorders (ERN eUROGEN) and rare kidney diseases (ERN ERKNet). The endpoint will be renal/patient survival at 2 years postnatally. Assuming α = 0.05, 1–β = 0.8 and a mean prevalence of severe renal outcome in PUV individuals of 0.35, 400 patients need to be enrolled to validate the previously reported sensitivity and specificity of the peptide signature.

Results

In this largest multicentre study of antenatally detected PUV, we anticipate bringing a novel tool to the clinic. Based on urinary peptides and potentially amended in the future with additional omics traits, this tool will be able to precisely quantify postnatal renal survival in PUV pregnancies. The main limitation of the employed approach is the need for specialized equipment.

Conclusions

Accurate risk assessment in the prenatal period should strongly improve the management of fetuses with PUV.

Hirschsprung's disease in a child with posterior urethral valve: An unwanted association

Urinary bladder and the rectum share a common embryological origin, and the anatomical proximity of these two organs suggest that a dysfunction in either may influence the function of the other. Although, the coexistence of bladder and bowel dysfunction has been previously reported in the literature, there are hardly any reports on coexistence of posterior urethral valve (PUV) with Hirschsprung's disease. Here, we report a case of a 20-month-old male child who was initially treated for PUV and was later found to have coexisting Hirschsprung's disease.

Long-term renal outcome in infants with congenital lower urinary tract obstruction

INTRODUCTION

Congenital Lower Urinary Tract Obstructions (LUTO) is a heterogeneous group of diseases in which urine elimination is obstructed at the level of bladder neck or urethra. The aim of the study is to evaluate the long-term renal outcome of patients suffering of congenital LUTO.

PATIENTS AND METHOD

We retrospectively reviewed patients with congenital LUTO. All patients had at least 1 year follow-up. Data on surgery, renal imaging and Schwartz estimate creatinine clearance were collected. Incidence of Chronic Renal Disease (CRD) is presented with Kaplan-Meier method.

RESULTS

40 patients were included, 23 patients with Posterior Urethral Valve (PUVs) and 17 patients with other aetiologies: anterior urethral valve (2), urethral atresia (2), urethral stenosis (2), cloacal malformations (2), obstructive ureterocele (1), bladder trigone malformation (1) and neonatal bladder-sphincter dysfunction without neurological abnormalities (7). Incidence of CRD at age 10 years was 37% in congenital LUTO, 42% in PUVs and 30% in other aetiologies, and was significantly higher in PUVs (P=0.032). Renal prognosis was significantly worsened by discover of retentional bladder wall changes in initial cystoscopy, and by loss of parenchymal differentiation or cortical microcysts in first ultrasonography. The use of urinary diversion was significantly higher in LUTO of other aetiologies.

CONCLUSION

A high incidence of CRD is observed in patients with congenital LUTO, significantly higher in patients with PUV. LUTO of other aetiologies require step by step surgical management and higher use of urinary diversion. Precise initial evaluation in cystoscopy and ultrasonography is required and participate to evaluate future renal outcome.

LEVEL OF INCIDENCE

4.

Solitary functioning kidney in children: clinical implications

Introduction:

Children with solitary functioning kidney (SFK) are prone to develop long term problems, which are not well represented in the literature. The extent to which the presence of associated congenital anomalies of kidney and urinary tract (CAKUT) further de-stabilize renal function is to be addressed.

Objective:

This study was conducted to evaluate the etiology, presentation, presence of CAKUT, and renal damage in children with SFK.

Methods:

All children with SFK who presented to the department of pediatric surgery from March 2014 to May 2016 were included in the study. Children with malignancy were excluded from the study.

Results:

Of the 20 patients with SFK, 14 (70%) had primary SFK (8 with agenesis and 6 with multicystic dysplastic kidney), 6 (30%) belonged to secondary SFK group, among them 3 had pelviureteric junction obstruction, 2 had posterior urethral valves and 1 had vesicoureteric reflux. Eight (40%) had associated CAKUT, 4 (20%) were asymptomatic while 8 (40%) had UTI and 6 (30%) had hypertension. Ten (50%) patients had reduced glomerular filtration rate (GFR) suggesting compromised renal function.

Conclusion:

Children with SFK have high morbidity especially when associated with ipsilateral CAKUT. Long-term periodical follow up is essential in these patients to improve clinical outcome.

Parents Refusing Dialysis for a 3-Month-Old With Renal Failure

A 3-month-old boy with failure to thrive was referred to a nephrology clinic after a diagnostic workup for failure to thrive revealed a serum urea nitrogen level of 95 mg/dL and creatinine level of 3.6 mg/dL. A renal ultrasound revealed marked bilateral hydronephrosis with little remaining renal cortex in either kidney. A voiding cystourethrogram revealed evidence of posterior urethral valves. The child had no evident comorbidities. Fulguration of the valves was successfully performed but did not lead to improvement in kidney function. The nephrologists recommended the initiation of dialysis with the hope that the child would be able to receive a kidney transplant in the future. After careful consideration, the family stated that they did not want this child to suffer with a lifetime of dialysis and transplant care. They were also concerned about the impact of this child's illness on their other 2 children and their family. They requested that their son be provided with palliative care only. Experts in nephrology, bioethics, and critical care discuss the ethical issues raised by this parental request.

Foetal surgery: Anaesthetic implications and strategic management

Intrauterine surgery is being performed with increasing frequency. Correction of foetal anomalies in utero can result in normal growth of foetus and a healthier baby at delivery. Intrauterine surgery can also improve the survival of babies who would have otherwise died at delivery, or in the neonatal period. There are three commonly used approaches to correct foetal anomalies: open surgery, where the foetus is exposed through hysterotomy; percutaneous approach, where needle or foetoscope is inserted through the abdominal wall and the uterine wall; finally, ex utero intrapartum treatment (EXIT) surgery, where the intervention is performed on the baby before terminating the maternal umbilical support to the baby. Anaesthetic management of the mother and the foetus requires good understanding of maternal physiology, foetal physiology, and pharmacological and surgical implications to the foetus. Uterine relaxation is a critical requisite for open foetal procedures and EXIT procedures. General anaesthesia and/or regional anaesthesia can be used successfully depending on the nature of foetal intervention. Foetal surgery poses complications not only to the foetus but also to the mother. Therefore, the decision for undertaking foetal surgery should always consider the risk to the mother versus benefit to the foetus.

Inhibition of HIF Reduces Bladder Hypertrophy and Improves Bladder Function in Murine Model of Partial Bladder Outlet Obstruction

PURPOSE

Posterior urethral valves are the most common cause of partial bladder outlet obstruction in the pediatric population. However, to our knowledge the etiology and the detailed mechanisms underlying pathological changes in the bladder following partial bladder outlet obstruction remain to be elucidated. Recent findings suggest that hypoxia and associated up-regulation of HIFs (hypoxia-inducible factors) have a key role in partial bladder outlet obstruction induced pathology in the bladder. We examined the effects of pharmacological inhibition of HIF pathways by 17-DMAG (17-(dimethylaminoethylamino)-17-demethoxygeldanamycin) in pathophysiological phenotypes after partial bladder outlet obstruction.

MATERIALS AND METHODS

Partial bladder outlet obstruction was surgically created in male C57BL/6J mice. The animals received oral administration of 17-DMAG or vehicle daily starting from the initiation of obstruction up to 5 days. Sham operated mice served as controls. Bladders were harvested from each group 2, 4 and 7 days postoperatively, and analyzed for histological and biochemical changes. Bladder function was assessed by in vitro muscle contractility recordings.

RESULTS

Partial bladder outlet obstruction caused a significant increase in the bladder mass accompanying enhanced collagen deposition in the bladder wall while 17-DMAG treatment suppressed those increases. Treatment with 17-DMAG attenuated the degree of up-regulation of HIFs and their target genes involving the development of tissue fibrosis in obstructed bladders. Treatment with 17-DMAG improved the decreased responses of obstructed bladder strips to electrical field stimulation and KCl.

CONCLUSIONS

In vivo 17-DMAG treatment decreased partial bladder outlet obstruction induced pathophysiological changes in the bladder. HIF pathway inhibition has a potential clinical implication for the development of novel pharmacological therapies to treat bladder pathology associated with partial bladder outlet obstruction.

Maternal anesthesia for fetal surgery

This article describes the anesthetic management of pregnant women undergoing fetal surgery. Discussion includes general principles common to all fetal surgeries as well as specifics pertaining to open fetal surgery, minimally invasive fetal surgery, and ex utero intrapartum therapy (EXIT) procedures.