Retropancreatic fascia is absent along the pancreas facing the superior mesenteric artery: a histological study using elderly donated cadavers.

To determine the fascial configuration between the superior mesenteric artery and vein and the posterior aspect of the pancreas, we examined histological sections of 10 elderly donated cadavers without pathology in the abdomen. The retropancreatic fascia was absent along the pancreatic parenchyma facing the artery and vein. Abundant nerves along the artery were separated from the pancreas by loose tissue almost 10 mm in thickness. In addition, anterior renal fasciae facing the pancreatic body were not evident in these specimens, possibly due to the degeneration of the left adrenal gland with age. Thus, a definite renal fascia was restricted on the lateral and posterior sides of the left kidney. These findings suggest that interactions between a pancreatic tumor and nerves would require migration of cancer cells over a long distance. Conversely, attachment of the enlarged tumor mass to the nerves may be necessary for the invasion. The anterior renal fascia may fuse with the retropancreatic fascia.