Mesocolon

The mesocolon is traditionnaly defined as the part of the mesentery that attaches the colon to the abdominal wall. The mesocolon was formerly thought to be a fragmented structure, with all named parts, separately terminating their insertion into the posterior abdominal wall.

Since 2012, new approach consider the mesentery as a single structure. This structure termed "mesenteric organ" is continuous from duodenojejunal flexure to mesorectum, spanning the gastrointestinal tract between. Recent histologic findings have demonstrated that although apposed to the retroperitoneum, the mesenteric organ is separated from this via Toldt’s fascia. The parts of the mesentery organ attached to the colon are:

• The transverse mesocolon is that section of the mesentery attached to the transverse colon that lies between the colic flexures.

• The ascending mesocolon is that section of the mesentery attached to the ascending colon and accoladed to the posterior adominal wall.

• The descending mesocolon is that section of the mesentery attached to the descending colon and accoladed to the posterior adominal wall..

• The sigmoid mesocolon is that region of the mesentery to which the sigmoid colon is attached at the gastrointestinal mesenteric margin.