Pelviureteric junction obstruction

What it is

PUJ obstruction is one of the causes of hydronephrosis, and hydronephrosis is either congenital or acquired.

• Intrinsic, e.g. abnormal peristalsis.
• Extrinsic, e.g. an aberrant renal artery to the inferior pole of the kidney that compresses the ureter.

The mark of a typical congenital UPJ obstruction is a dilated pelvis and a ureter that is not dilated. That single line separates it from an obstruction lower down.

How it presents

A 24-year-old woman presents with occasional dull aching pain in the right loin. She denies any fever or dysuria. Ultrasonography shows moderate dilatation of the right renal pelvis without any ureteric dilatation.