Anatomy of the retroperitoneum: observations of the distribution of pathologic fluid collections.

PURPOSE: To correlate anatomic dissections with clinical observations regarding anatomic distribution of retroperitoneal fluid, and to document the existence of planes that lie between classically described retroperitoneal spaces. MATERIALS AND METHODS: Latex was injected in varying amounts into the pancreatic tail in three fresh cadavers to simulate peripancreatic fluid collections. Spiral computed tomography (CT) was performed of the abdomen and pelvis after each latex injection. Two cadavers were subsequently frozen and sectioned in axial planes; limited dissections were performed on these specimens. One was embalmed and underwent extensive anatomic dissection. Five embalmed, unprepared cadavers were also dissected to confirm observations made in the three prepared cadavers. RESULTS: Latex injected into the tail of the pancreas entered a retromesenteric plane that was posterior to the anterior pararenal space and anterior to the anterior renal fascia. The plane continued superiorly, extending to the di...