mesorectum

The mesorectum is a fold of peritoneum that anchors the rectum to the posterior abdominal wall. It extends from the sigmoid colon down to the level of the anorectal junction. Within the mesorectum are the superior rectal artery and vein, as well as lymphatic vessels and nerves that supply the rectum. The mesorectum is a critical structure in rectal surgery, as its proper removal, known as total mesorectal excision (TME), is essential for achieving good oncological outcomes in rectal cancer treatment. The integrity of the mesorectal fascia, the outer layer of the mesorectum, is a key indicator of the completeness of the surgical resection. Disruption of this fascia can lead to local recurrence of cancer. Understanding the anatomy and surgical significance of the mesorectum is therefore fundamental for colorectal surgeons.