ABSTRACT
With the widespread use of maternal ultrasound, the incidence of hydronephrosis has increased, significantly altering the practice of urology. Pelvi-ureteric junction (PUJ) obstruction is the most common cause of hydronephrosis detected antenatally.1,2 Next most common cause of prenatally detected hydronephrosis is obstruction at the uretero-vesical junction (UVJ).1 Management of these patients after birth remains controversial. The decision to intervene surgically in these infants has become more complex because spontaneous resolution of antenatal and neonatal upper urinary tract dilatations is being increasingly recognized.1,3-5 The recognition and relief of significant obstruction is important to prevent irreversible damage to the kidneys.6 Differentiating urinary tract dilatations that are significantly obstructive and require surgery from those that represent mere anatomical variants with no implications for renal function is not a simple task, especially in the newborn. Recently, interest has developed using the function in involved kidney as a measure of degree of obstruction.3,4
The overall incidence of PUJ obstruction approximates one in 1500 births. The ratio of males to females is 2 : 1 in the neonatal period, with left-sided lesions occurring in 60%. In the newborn period, a unilateral process is most common, but bilateral PUJ obstruction was found in 10-49% of neonates in some reported series.7 PUJ obstruction is classified as intrinsic, extrinsic, or secondary.
