Clinical and radiological characteristics of Nigerian boys with posterior urethral valves.

Posterior urethral valve (PUV) obstruction is the most common cause of bladder outlet obstruction in boys. Currently, the diagnosis of PUV is commonly made prenatally. In our environment, however, prenatal diagnosis is rare and the diagnosis is usually made postnatally from the clinical and radiological features. This study therefore examines the clinical and radiological spectrum of boys with PUV in our environment. We examined the clinical presentations, ultrasonographic and the micturating cystourethrographic (MCUG) features of boys with PUV in our institution over a 22-month period from June 2006. There were 28 patients with PUV over this period. The age at presentation ranged from 11 days to 11 years (mean age = 2.7 years). Although prenatal ultrasound scan was done in 23 (82.1%) patients, no prenatal diagnosis was made in any of the patients. The diagnosis was made after infancy in 16 (57.1%) patients. Recurrent urinary tract infection (UTI) was the most common mode of presentation occurring in 14 (50.0%) patients with 7 (50.0%) of the patients with UTI presenting with septicaemia. Voiding dysfunctions, which occurred in all the patients, were the primary mode of presentation in 12 (42.9%) patients. Three (10.7%) patients presented with renal insufficiency, which was significantly associated with the age at presentation (P = 0.026). Ultrasound scan done in the postnatal period strongly suggested the diagnosis of posterior urethral valves in 22 (78.6%) patients in whom the posterior urethra was found to be dilated, associated with thick-walled urinary bladder and bilateral hydronephrosis. Trabeculations of the bladder was a constant feature on MCUG. Other features on MCUG included dilatation of the posterior urethra in 26 (92.8%), bladder diverticuli in 15 (53.6%) and unilateral and bilateral vesicoureteric reflux in 3 (10.7%) and 1 (3.6%) patient(s), respectively. The diagnosis of PUV obstruction which is often made late in our environment, is mainly by clinical, sonographic and MCUG features in the postnatal period. A majority of patients present late, with recurrent UTI.