An abnormal passage in any part of the URINARY TRACT between itself or with other organs.

An encapsulated accumulation of URINE in the retroperitoneal area. It has the appearance of a cyst (CYSTS). Urinoma is usually caused by URETERAL OBSTRUCTION, renal trauma or perforation of the renal collecting system.

Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body.

An abnormal direct communication between an artery and a vein without passing through the CAPILLARIES. An A-V fistula usually leads to the formation of a dilated sac-like connection, arteriovenous aneurysm. The locations and size of the shunts determine the degree of effects on the cardiovascular functions such as BLOOD PRESSURE and HEART RATE.