Management of Perirenal Fluid Collections

Abstract

The perirenal space may be involved with diseases that arise within or outside it. Extraperitoneal fluid collections consist of blood, pus, urine, lymph, or pancreatic fluid [1–3]. Except for acute or subacute hemorrhage, these different collections of fluid are indistinguishable on computed tomography (CT) scans or with ultrasound. The presence of extraluminal gas usually indicates an abscess caused by gas-forming organisms or an enteric communication. Urinomas tend to be cystic, whereas hematomas may be solid, cystic, or a combination of both, depending on the stage of clot breakdown. Ultrasound offers an accurate, noninvasive, radiation-free means of following the presence and course of perinephric hematomas resulting from blunt trauma. Although sonography can show extraperitoneal fluid collections, it is much less effective than CT. Sonography is hampered by overlying bowel gas and, more important, cannot show fascial planes [4,5,6]. After intravenous injection of contrast medium, however, enhancement of adjacent organs may make it difficult to recognize the high attenuation of retroperitoneal blood [7]. Retroperitoneal hemorrhage can be detected and localized to any of the extraperitoneal compartments by using CT.