In patients with posterior urethral valves (PUV), severe unilateral vesicoureteral reflux (VUR) is one of the three conditions associated with preservation of renal function. Others are urinary ascites or urinoma in newborns and large congenital bladder diverticula. These conditions most likely provide a pop-off mechanism preventing the development of high intravesical pressure. Only 5% of patients with PUV and an associated pop-off mechanism will develop renal failure as opposed to40 % of patients with PUV without a protective factor.
We present a 3-year-old boy with posterior urethral valves and a severe right unilateral vesicoureteral reflux. He had PUV ablation with Mohan’s valvotome and made satisfactory post operative recovery with indication on follow-up of preservation of renal function.
Keywords: Posterior Urethral Valves, Unilateral Vesicoureteral Reflux, Hydrocalycosis
Congenital anomalies of the lower urinary tract are a significant cause of morbidity in infancy. Radiologic investigation is an important source of clinical information in lower urinary tract disorders but should not inconvenience the patient, expose the patient to unnecessary radiation, or delay surgical correction. In pediatric patients with suspected underlying urologic structural anomalies, screening ultrasonography is commonly the initial diagnostic study. If dilatation of the urinary tract is confirmed, micturating cystourethrography (MCUG) is performed to determine the presence of vesicoureteric reflux (VUR) and other causes of upper tract dilatation.1
Posterior urethral valves (PUV) are by far the most common congenital obstructive lesion of the urethra, occurring mainly in phenotypic boys.1 Young et al initially classified posterior urethral valves into three types, but it is now clear that there is only one type (formerly called type I).2 MCUG is the best imaging technique for the diagnosis of posterior urethral valves.1 VUR is the abnormal flow of urine from the bladder into the upper urinary tract. In the majority of cases, it occurs as a result of a primary maturation abnormality of the vesicoureteral junction or a short distal ureteric submucosal tunnel in the bladder that alters the function of the valve mechanism.3 VUR may be associated with PUV.4 Unilateral reflux, may occur in up to 35% of boys with PUV, and has been linked with protected renal function.5
This is a case of PUV with a severe unilateral VUR. The severity and unilateralism of the VUR prompted this report.
A 3-year-old male was referred to the University College Hospital (UCH) Ibadan where he presented with poor urinary stream since birth, urinary frequency and abdominal distension of 2 months duration.
His parents first noticed his difficulty with micturition at 3months of age; he usually strained at micturition with a poor urinary stream and terminal dribbling. These symptoms were associated with recurrent fever and failure to thrive.
Patient had groin surgery at 18months of age, presumably a hydrocelectomy at a private hospital on account of scrotal swelling with no significant improvement.
He was later transferred to a mission hospital where he had an ultrasound examination for the first time which showed bilateral hydronephrosis and distended urinary bladder; an impression of obstructive uropathy with urinary retention from a possible PUV was made. He was later catheterized to relieve obstruction and referred for definitive management.
Dr Ogbole G .I.
Department of Radiology,
University College Hospital, Ibadan.
PMB 5116 Ibadan,Nigeria.