Sigmoid Mesocolon

mesocolon sigmoideum

The sigmoid mesocolon is a V-shaped peritoneal fold attaching the sigmoid colon to the posterior abdominal wall, with its apex pointing to the left ureter at the pelvic brim.

Region: Abdomen

Biomechanics

Function & Actions

Suspends the sigmoid colon, transmits the sigmoid arteries and veins from the inferior mesenteric vessels, and provides the mesenteric attachments relevant in sigmoid colectomy and low anterior resection.

Clinical Relevance

Clinical Notes

The apex of the sigmoid mesocolon V reliably overlies the left ureter — a key landmark for ureteral identification during left-sided colorectal surgery. Sigmoid mesocolon defects cause intersigmoid hernias. In Hartmann's reversal, the sigmoid mesocolon remnant must be mobilised to allow tension-free colorectal anastomosis.

Pathology

Common Injuries & Conditions

Left Ureter Identification at Sigmoid Mesocolon Apex

The apex of the V-shaped sigmoid mesocolon overlying the left ureter provides the surgical landmark for safe ureteral identification during left colectomy.

Intersigmoid Hernia

Internal herniation through the intersigmoid fossa in the sigmoid mesocolon apex producing small bowel obstruction.