Mesocolon

Peritoneal fold in which the vessels and nerves travel, for the suspension and the supply of the colon.

Feneis 210.16

The mesocolon was thought to be a fragmented structure, with all named parts—the ascending, transverse, descending, and sigmoid mesocolons, the mesoappendix, and the mesorectum—separately terminating their insertion into the posterior abdominal wall.

However, in 2012, new microscopic and electron microscopic examinations showed the mesocolon to be a single structure derived from the duodenojejunal flexure and extending to the distal mesorectal layer.

The mesocolon regions were traditionally taught to be separate sections with separate insertions into the posterior abdominal wall.

In 2012, the first detailed observational and histological studies of the mesocolon were undertaken and this revealed several new findings.

The study included 109 patients undergoing open, elective, total abdominal colectomy.

Anatomical observations were recorded during the surgery and on the post-operative specimens.

These studies showed that the mesocolon is continuous from the ileocaecal to the rectosigmoid level.

It was also shown that a mesenteric confluence occurs at the ileocaecal and rectosigmoid junctions, as well as at the hepatic and splenic flexures and that each confluence involves peritoneal and omental attachments.

The proximal rectum was shown to originate at the confluence of the mesorectum and mesosigmoid.

A plane occupied by perinephric fascia was shown to separate the entire apposed small intestinal mesentery and the mesocolon from the retroperitoneum.