From the Research
When the inferior mesenteric artery is ligated, the sigmoid colon receives its arterial blood supply primarily from the superior hemorrhoidal artery, which is a branch of the inferior mesenteric artery that remains patent even after ligation, as well as from collateral circulation provided by the marginal artery of Drummond and other anastomoses between the superior mesenteric artery and inferior mesenteric artery territories. The blood supply to the sigmoid colon after ligation of the inferior mesenteric artery is a critical consideration in surgical procedures such as colorectal surgeries or abdominal aortic aneurysm repairs.
- The superior hemorrhoidal artery plays a significant role in supplying blood to the sigmoid colon and rectum, as demonstrated by a study published in 1976 1.
- The marginal artery of Drummond, formed by anastomoses between branches of the superior mesenteric artery and the inferior mesenteric artery, also provides a collateral pathway for blood supply to the sigmoid colon.
- Additionally, other anastomoses such as the arc of Riolan (meandering mesenteric artery) contribute to the collateral circulation between the superior mesenteric artery and inferior mesenteric artery territories.
- A recent study published in 2021 2 redefined the collateral system between the superior mesenteric artery and inferior mesenteric artery, highlighting the importance of understanding the vascular anatomy to prevent ischemic damage to the descending colon during surgical procedures.
- The effectiveness of this collateral circulation depends on individual anatomical variations and the patient's vascular health, emphasizing the need for careful evaluation of the vascular anatomy before ligating the inferior mesenteric artery. Some of the key arteries involved in the blood supply to the sigmoid colon include:
- Superior hemorrhoidal artery
- Marginal artery of Drummond
- Arc of Riolan (meandering mesenteric artery)
- Middle colic artery
- Left colic artery
- Sigmoid arteries It is essential to consider the potential risks of ischemia to the sigmoid colon after ligation of the inferior mesenteric artery, particularly in patients with inadequate collateral circulation, and to carefully evaluate the vascular anatomy before performing such procedures, as supported by studies such as those published in 1993 3 and 1999 4.