Box 4 Recommendations of French national diagnostic and care protocol (NDCP) for posterior urethral valves (PUV)

Recommendation 1

There are no studies defining the likelihood of or diagnostic scores of ultrasound criteria for PUV. When PUV is suspected, the probability of the diagnosis is determined based on the ultrasound findings during a multidisciplinary discussion, then perinatal management is proposed

Recommendation 2

These three criteria, when present, strongly suggest a progression to fetal renal failure. When none of these criteria is present on ultrasound, the prognosis is usually more reassuring but does not exclude renal failure in childhood. Finally, it is important to remember that sequential screening of these ultrasound parameters must be performed as they may develop one after the other in these fetuses. In the most complex situations, the ultrasound picture is incomplete with the presence of only one or two criteria, making prenatal advice particularly difficult. Second line investigations must be performed in these cases, in particular fetal biochemistry to obtain further prognostic information

Recommendation 3

These prenatal biochemical tests improve the advice given to parents after assessing the renal prognosis of their unborn child. The two types of samples (urine or blood) provide different information. The choice of test is made according to the gestational age and the presentation of the fetus. Fetal urine can also be used if urodigestive fistulae are suspected. The differential diagnosis with MMIHS is very interesting in cases where the US give no clear information. The laboratory should be provided with fetal urine and amniotic fluid for this specific diagnosis. Because of their invasiveness these tests are often only indicated in cases with signs of severity on ultrasound. Strict indications are listed as below:

Poor progression of ultrasound features

Assessment before possible in utero treatment

Assessment before possible termination of pregnancy when a poor prognosis is suspected

Recommendation 4

Patients with a fetus presenting with LUTO should be referred to an expert prenatal diagnostic center. The evaluation will confirm or infirm the diagnosis of LUTO and the causes (including PUV), search for associated morphological and chromosomal abnormalities, and provide a prognostic assessment. A multidisciplinary consultation including neonatologists, pediatric urologists and pediatric nephrologists should be offered when PUV is suspected. Prenatal therapeutic management may be considered, presenting the risks associated with the procedure and the uncertainty of the expected benefit, particularly in terms of renal function. The patient may request termination of pregnancy, which should then be discussed at the Multidisciplinary Center for Prenatal Diagnosis. Finally, a “wait and see” option can be offered. If possible, the birth should be organized in a level 3 maternity hospital with an onsite pediatric urologist and a pediatric nephrologist to provide immediate multidisciplinary neonatal care

Recommendation 5

Early endoscopic intervention Perform neonatal endoscopic valves ablation within 48 h after birth for clinically stable newborns. Use a cold knife for the valve section to minimize the risk of postoperative urethral strictures; Utilize miniaturized endoscopic instruments (< 2 mm) for newborns weighing more than 2000 g

Management of low birth weight infants For newborns weighing less than 2000 g, prioritize bladder drainage through diversion techniques; Consider vesicostomy as the preferred temporary diversion to preserve renal function until the infant is stable enough for valve section

Temporary urinary diversions Use Sober’s cutaneous ureterostomy in cases where vesicostomy is unsuccessful or as an alternative. This approach preserves part of the bladder function; Reserve pyelostomy/nephrostomy for cases complicated by urinary tract infection or pyonephrosis as a temporary measure

Recommendation 6

Two algorithms for the management of PUV at birth and at follow-up are proposed in Fig. 2 and 3 respectively

Recommendation 7

(suggested frequency based on expert experience and current practice, to be adapted according to clinical course)

Renal and bladder ultrasound: one month after the endoscopic resection and then every three months for the first year, then annually

Post-operative control VCUG: to be performed according to the clinical progression and ultrasound results

DMSA scan: at 6 months

Recommendations 8

Regular bladder function assessments Conduct routine assessments of bladder function, including uroflowmetry with electromyography and post-void residual (PVR) measurements, at each follow-up visit; Perform urodynamic studies at defined intervals to monitor bladder compliance and detrusor function, distinguishing between overactive high-pressure bladders and hypoactive large-capacity bladders

Management of bladder dysfunction Initiate early use of anticholinergic therapy, such as oxybutynin, in infants with high voiding pressures and/or low bladder capacity post-endoscopic PUV section to improve bladder function and capacity; Consider adding alpha-blockers (e.g., alfuzosin) to decrease outlet resistance and promote bladder emptying if anticholinergic therapy alone is insufficient

Clean Intermittent Catheterization (CIC) Introduce CIC in children with significant PVR, recurrent febrile urinary tract infections (fUTIs), or worsening upper urinary tract dilation and renal function impairment; Educate families on proper CIC techniques, ensuring they understand the importance of regular catheterization to prevent urinary retention and associated complications

Monitoring and management of urinary tract infections (UTIs) Implement prophylactic measures, including antibiotic prophylaxis and circumcision, to reduce the incidence of recurrent fUTIs; Provide guidance on early recognition and treatment of UTIs to prevent renal damage

Long-term follow-up Schedule regular follow-up visits to monitor renal function, bladder dynamics, and overall growth and development; Include routine renal and bladder ultrasounds, initially performed monthly and then at longer intervals based on clinical progress, to assess the progression of urinary tract dilation and bladder wall changes

Transitional care to adult services Plan for a structured transition from pediatric to adult urology and nephrology services, ensuring continuous and consistent care into adulthood; Facilitate communication between pediatric and adult care teams to maintain comprehensive management of bladder dysfunction and renal health

Patient and family education Provide ongoing education to patients and their families regarding the importance of adherence to follow-up schedules, medication compliance, and the management of bladder dysfunction; Offer psychological support and counseling to address the emotional and social challenges associated with long-term bladder management and potential renal complications

Use of imaging in follow-up Perform annual renal and bladder ultrasounds to monitor kidney growth, detect new cortical scars, and assess bladder wall thickness and regularity; Utilize dimercaptosuccinic acid (DMSA) renal scintigraphy to evaluate relative renal function and search for cortical scars, providing prognostic information

Recommendations 9

Managing Stage V renal failure in children with posterior urethral valves (PUV) involves early identification, continuous monitoring, and a multidisciplinary approach. Regular assessments of renal function, including serum creatinine, blood urea nitrogen, electrolytes, blood pressure, and proteinuria, are essential. A team of pediatric nephrologists, urologists, dieticians, and psychologists provides comprehensive care and supports families through education and counseling

Preparation for dialysis should prioritize peritoneal dialysis for younger children, with necessary procedures like gastrostomy performed beforehand to minimize infection risks. Nutritional management is crucial to support growth and maintain fluid and electrolyte balance, utilizing specialized formulas with reduced phosphorus and potassium. Psychosocial support is vital to help families cope with the emotional and social challenges of long-term dialysis

Pre-emptive renal transplantation (RT) is preferable to avoid prolonged dialysis, with bladder preparation starting years in advance. Regular urodynamic assessments are necessary to manage bladder dysfunction effectively. Post-transplantation follow-up ensures monitoring for urological complications, adherence to immunosuppressive therapy, and long-term graft survival

Addressing complications such as growth retardation, anemia, metabolic bone disease, and cardiovascular health through appropriate medical and dietary interventions is essential. Implementing these recommendations improves outcomes and quality of life for children with Stage V renal failure due to PUV, ensuring a structured and comprehensive approach to their care

By following these guidelines, healthcare providers can significantly improve the prognosis and overall well-being of patients with Stage V renal failure caused by PUV, ultimately leading to better long-term health outcomes and quality of life

Recommendation 10

The management of CKD is multidisciplinary and includes the paramedical team (social worker, nurse specialized in patient education, dietician, clinical psychologist) who are familiar with CKD. Psychological support for the child and the family is an essential aspect for the balanced development of a child who is subject to these constraints

Recommendation 11

Medical and social care is discussed after the patient’s situation has been assessed and medical and family information has been obtained. Several points are taken into account:

Ensure that a care protocol is in place

When the child’s state of health requires the presence of a parent for compulsory care, a parental presence leave may be negotiated with the employer with a daily parental presence allowance

Possibility of setting up a specific file to: i) recognize the disability; ii) payment of an allowance; iii) support needs at school; iv) educational and medico-social referrals; and v) professional orientations