Posterior urethral valves in South African boys: Outcomes and challenges

Posterior urethral valves (PUV) are a common cause of congenital obstructive nephropathy. The outcome of patients with PUV at Chris Hani Baragwanath Academic Hospital in Johannesburg, South Africa, has not been documented previously.

To describe the outcome of patients diagnosed with PUV over a 29-year period from January 1985 to December 2013, and to analyse risk factors for chronic kidney disease.

This was a retrospective record review of boys aged <14 years diagnosed with PUV at Chris Hani Baragwanath Academic Hospital. PUV was diagnosed by a voiding cystourethrogram (VCUG) and/or at cystoscopy. Valves were resected primarily or after vesicostomy. The glomerular filtration rate was calculated using the Schwartz formula, and stratified as normal or decreased for age at presentation and at the final visit.

Records of 181 patients were analysed. The diagnosis was made during the first year of life in 139 patients (76.8%). Clinical presentation included urinary tract infection (UTI) in 109 patients (60.2%), palpable bladder in 98 (54.1%), palpable kidney in 85 (46.9%), and poor urinary stream in 78 (43.1%). An ultrasound scan was reported normal in 10.9%. Vesicostomy was performed in 80 patients (44.2%) and primary valve ablation in 101 (55.8%), with vesicostomy being more prevalent in the pre-2000 era. The median duration of follow-up was 21 months (interquartile range 5 - 79) and renal outcome at last visit was normal in 117 patients (64.6%). The presence of bladder diverticula was associated with a favourable renal outcome. Thirteen patients (7.2%) died, and 102 (56.3%) defaulted from follow-up.

PUV frequently presents with UTI and palpable bladder and/or kidneys. Findings on ultrasound were normal in 10.9% of our patients with PUV. A VCUG is indicated in the presence of palpable kidneys or bladder even if the ultrasound scan is normal. Bladder diverticula as a pressure-release mechanism are renoprotective. Vesicostomy or primary valve ablation did not affect final renal outcome. Chronic kidney disease occurred in 34.8% of patients after surgical correction. Adherence to scheduled appointments is problematic in this population. Long-term follow-up is mandatory.