Urinary system

Systema urinarium

The urinary tract is among the districts where the usual configuration is least constant: the number and position of the kidneys, the course of the ureters and the origin of the renal vessels vary often enough to be encountered in ordinary practice. The horseshoe kidney, which joins the two lower poles in front of the great vessels, occurs in roughly 1 in 400-500 births and alters both the surgical approach and the reading of abdominal imaging. Supernumerary renal arteries and ureteral duplications matter just as much: the former affect kidney retrieval and transplantation and endovascular procedures on the aorta, the latter may be accompanied by reflux or ectopic openings that explain otherwise obscure incontinence. Recognising these configurations before an operation or an endourological manoeuvre reduces the risk of vascular and ureteral injury, and allows a constitutional finding to be told apart from an acquired lesion.