Introduction

Posterior urethral valves are the commonest congenital obstruction of the lower urinary tract, comprising 10% of antenatally diagnosed uropathies with an incidence of up to 1 in 4000. This figure will rise if non-viable and terminated fetuses are included and as antenatal diagnosis is refined. Equally, there is a group of boys at the other end of the spectrum, whose lesser urethral obstruction produces no early urinary tract dilatation and who present late, even in adulthood with normal renal function and voiding difficulty. The interpretation of this latter group accounts for much of the variation in incidence and the different spectrum of severity found in different series of valve patients.

Posterior urethral obstruction more than any other urinary anomaly, has the capacity to affect the development and function of the whole urinary tract. Our understanding of this problem has evolved over the past decades and has included the identification, classification and treatment of the obstruction; recognition and management of the degrees and types of renal impairment that may be associated with it; the approach to associated vesicoureteric reflux and dilated upper urinary tracts; the function and development of the “valve bladder” (a central issue in our current thoughts about the long-term outcome of posterior urethral valves) and finally the impact on our practice of antenatal diagnosis and the opportunities that it offers not only in the identification but also in the early treatment of posterior urethral valves.