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

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."

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.

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.

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.