superior rectal vein

The superior rectal vein is a venous vessel that drains the upper two thirds of the rectum and the upper anal canal. It is a tributary of the inferior mesenteric vein, placing it within the portal venous system.

The superior rectal vein is located along the upper rectum and upper anal canal, ascending to drain into the inferior mesenteric vein. It runs in the mesorectal tissue posterior to the rectum.

The superior rectal vein drains blood from the upper rectum and upper anal canal into the inferior mesenteric vein and ultimately the portal venous system, facilitating venous return from the lower gastrointestinal tract.

The superior rectal vein forms part of the portosystemic anastomosis at the anorectal junction, which may become dilated in portal hypertension—a condition associated with internal hemorrhoid formation. It is also relevant in rectal venous thrombosis.

The superior rectal vein is a venous vessel running in the perirectal connective tissue, visible on pelvic MRI or CT as a thin vessel along the posterior rectal wall ascending toward the inferior mesenteric vein.