[Diagnosis and percutaneous treatment of urinary collections and obstructions]

The collections encountered around the renal transplant are mainly lymphoceles, more rarely hematomas, abscesses and urinomas, the frequency of which constituting 12% of cases. Their diagnosis is usually made by sonography; the percutaneous puncture is guided by US or CT in order to define its nature and drain the cavity. Urinary obstruction (6% of the cases) may be detected by sonography or scintigraphy, but percutaneous pyelography is often required to confirm the obstruction, to precise its level and nature, and to guide the percutaneous procedure. In the case of urinoma (3% of the cases), ultrasound may be unclear and the urinary extravasation must be then confirmed by scintigraphy, postinjection delayed plain or CT scan films.