Anatomic communications between the three retroperitoneal spaces: determination by CT-guided injections of contrast material in cadavers.

Our findings show pathways and extensions of the perirenal, anterior pararenal, and posterior pararenal spaces that should be considered when assessing a variety of retroperitoneal diseases. Perinephric collections, such as hematomas and urinomas, have at least a potential conduit across the midline or into the pelvis. Our study explains how blood from a ruptured abdominal aortic aneurysm may enter either perinephric space. Anterior pararenal processes, such as pancreatitis or appendicitis, can extend into the pelvis or cross the midline, and posterior pararenal blood from trauma can also flow into the pelvis.