[Follow-up of kidney function in children with former posterior urethral valves]

Severe forms of posterior urethral valves involve the risk of upper urinary tract damage and impaired renal function. For this reason, 26 boys formerly (between January 1980 and December 1989) treated for high-grade urethral obstruction were re-examined with reference to renal function. Results were compared with observations in a control group of 26 boys matched for age and height undergoing minimal urological surgery. While there were no significant differences in haemoglobin, height, blood pressure or kidney volume, in 14 of 20 patients with normal glomerular filtration rate pathologic findings were recorded, most of which related to urine concentrating capacity, tubular phosphate handling and hyperparathyroidism. These observations necessarily have implications for treatment of such children even if they are assumed to have unimpaired renal function. In future, monitoring of renal function in children with former posterior urethral valves should include different tests, and in particular tests of concentration capacity and measurement of parathyroid hormone.