UPJ obstruction
Also written as: UPJ — ureteropelvic junction
Blockage at the junction between the renal pelvis and ureter, impeding urine flow.
Full Definition
Ureteropelvic junction obstruction is a congenital or acquired condition where urine flow is impeded at the connection point between the renal pelvis and the ureter. This is the most common cause of antenatal hydronephrosis and can present in infancy, childhood, or adulthood. The obstruction may be intrinsic (due to abnormal muscle development or crossing vessels) or extrinsic (from external compression). Treatment typically involves pyeloplasty or endoscopic procedures to restore normal drainage.
Usage
Usage note: Always spell out on first use, then abbreviate as UPJ. Avoid confusion with UVJ (ureterovesical junction).
In Context
- "Prenatal ultrasound revealed bilateral UPJ obstruction requiring postnatal evaluation." — Consultation note
- "The child's recurrent flank pain was attributed to UPJ obstruction." — Clinical assessment