Outcome and follow-up:
Based on the findings and treatment provided, it was recommended that retransplantation of the ureters onto the bladder should be carried out after three months. During the period of follow up there was not any complications reported and no urinary infections were observed.
Discussion:
Posterior urethral valves (PUV) are the most common form of lower urinary tract obstructions (LUTO) found in male pediatric patients. The embryonic abnormality responsible for PUV formation remains unknown. Some authors suggest that it may result from the abnormal fusion of the mesonephric duct into the urethra, while others suggest it is due to the persistence of the cloacal membrane. The overall incidence of LUTO is approximately 3.3 per 10,000 pregnancies and 2.3 per 10,000 live births. The overall prevalence is reported to be 3.34 per 10,000 births, ranging from 2.95 to 3.72.3,6
About 35% of cases are diagnosed in utero, and these cases are suspected when there is bilateral hydronephrosis, megacystis, and oligohydramnion or anhydramnion. On the other hand, 42% of cases are diagnosed during childhood, and the presenting symptoms include signs of urinary obstruction and infection.3 Our patient presented with loss of consciousness after a seizure; laboratory studies revealed high levels of creatinine and urea consistent with chronic kidney disease (CKD). Further assessment showed that the patient had PUV.
The predominant presentation that persists in almost all patients with PUV is voiding dysfunction (identified by poor stream, straining, and dribbling). Additional features may include anemia, bladder distension palpable above the pubic region, ascites, fever, ballotable kidneys, and inability to thrive.4 Many complications can occur due to the obstruction induced by PUV and it varies depending on the degree of obstruction and the patient’s age. The obstruction can range from minimal to severe resulting in bilateral severe hydroureteronephrosis because of the high pressure above the valve placement, chronic kidney disease (CKD) which may progress to end-stage kidney disease (ESKD), diverticular formation in the bladder, and even bladder rupture in severe cases.7,8 Even though PUV manifests with voiding dysfunction and CKD is considered a complication, our patient presented with no signs or symptoms of voiding problems, and CKD was detected during evaluation.
Micturating cysto-urethrogram (MCUG) is the most useful technique for diagnosis. Ultrasonography is considered an assistive diagnostic method especially for detecting complications such as diverticular formation in the bladder and hydroureteronephrosis.7,8 In this case, MCUG was not able to detect the valve which was then ablated during urethroscopy.
As we have seen in this case report, PUV can lead to an insidious progressive chronic kidney disease even after years of birth. As we know, PUV is not uncommon; therefore, practitioners should consider it as a differential diagnosis for CKD in any child even if their age at presentation is not typical. Moreover, heigh suspicion is needed if diagnostic assessment investigations show normal findings as in this case.