Pancreas: Peritoneal Reflections, Ligamentous Connections, and Pathways of Disease Spread

Abstract

The pancreas is a retroperitoneal organ with a close anatomic relationship to the peritoneal reflections in the abdomen, including the transverse mesocolon and the small bowel mesentery, and is directly contiguous to peritoneal ligaments such as the hepatoduodenal ligament, gastrohepatic ligament, splenorenal ligament, gastrocolic ligament, and the greater omentum. Understanding of these anatomic relationships of the pancreas is aided by knowledge of its embryologic development. These reflections and ligaments are potential pathways for spread of disease processes such as pancreatitis and pancreatic carcinoma. One can recognize these ligaments and reflections by identifying the blood vessels that traverse them.

Subperitoneal extension of disease processes between the chest, abdomen, and the pelvis

“…For example, the inflammatory changes of pancreatitis can spread into the transverse mesocolon, the greater omentum, the gastrocolic ligament, the root of the small bowel mesentery, and into the gastrohepatic and hepaticoduodenal ligaments (Fig. 10) [31]. It can also spread around the left kidney via the splenorenal ligament.…”

“…If the peritoneum is disrupted, this is referred to as transperitoneal spread. A common example is pseudocyst formation in the lesser sac in pancreatitis [31].…”

Imaging in Staging and Management of Pancreatic Ductal Adenocarcinoma

“…This complex relationship is better understood by learning the embryological development of the pancreas in the ventral and dorsal mesogastrium and their derivatives. These ligaments and peritoneal connections can be identified on cross sectional imaging by identifying the vascular structures that traverse these (Table 1) [3].…”

“…Although CT remains poor at detecting low volume peritoneal disease, knowledge of the peritoneal anatomy on CT and a meticulous search based on tumor location can greatly improve detection [3]. The most common CT finding is that of peritoneal thickening or small nodules; however larger nodules and omental caking can be seen occasionally.…”

“…Moreover, the complex network of blood vessels supplying the pancreas provides access to the spread of pancreatic adenocarcinoma along the neurovascular bundle. These have a direct bearing on prognosis, staging and resectability [3]. Imaging plays a key role in staging and evaluation of the disease.…”