Obstructive Uropathy Secondary to Posterior Urethral Valves: Retarding the Progression to End-Stage Kidney Disease in Children

Posterior urethral valve (PUV) is the most common cause of obstructive uropathy leading to chronic kidney disease (CKD) in male newborn infants. The few children that survive have poor prognosis, with over 50% progressing to end-stage kidney disease (ESKD) within ten years. This review aims to appraise the current interventions targeted at retarding the progression of the obstructive uropathy to late stages of CKD. With the current screening strategy, the majority of interventions are performed well after irreversible damage has occurred. Therefore, reduced mortality and improved long-term morbidity outcome from PUV will likely remain unattainable until it is possible to intervene before the onset of irreversible renal damage. Although fraught with complications and variable results, several prenatal interventions have been tried; these include vesicoamniotic shunting, vesicocentesis, fetal cystoscopy, or open fetal bladder surgery. The efficacy of these procedures however remains controversial. In retrospect, data on outcome of fetal intervention for PUV indicate that it is associated with risks of fetal and maternal morbidity or mortality without proven benefit for long-term renal outcome. The initial postnatal intervention of passing a continuously draining indwelling catheter may suffice in many cases albeit with some drawbacks. Primary valve ablation however remains the gold standard for treatment of PUV, with vesicostomy reserved for selected cases such as the very ill infant or younger infants where catheter passage is impossible or very difficult. Nonetheless, urinary diversion must be considered in selected cases with clear goals and endpoints in mind. The frequency of chronic and progressive renal impairment underscores the importance of long-term evaluation for all patients with PUV. Serial measurements of renal function, periodic urinalysis, blood pressure checks, and growth monitor should be performed for such patients.