*2.1. UPJO*

Congenital obstructive nephropathy reflects maldevelopment of the urinary tract in utero. Most commonly, lesions lie in the ureteropelvic junction (UPJ), causing chronic renal failure. Rapid diagnosis and treatment are essential to preserving function and slowing renal damage. The prevalence is one in 1500 live births [2]. Although UPJO is less common in adults, the condition is not rare [3]. In addition to having a congenital cause, acquired stenosis of the UPJ may follow an upper urinary tract infection, the development of stones, trauma, or ischemia. Vessels that compress or distort the UPJ when crossing the urinary tract may obstruct ureteral outflow in adults.
