Skip to content

Meandering Artery of Moskowitz (Arc of Riolan) (1)

Meandering Artery of Moskowitz (Arc of Riolan)

  • Anatomy: The Meandering Artery of Moskowitz, also known as the Arc of Riolan, is an arterial connection between the superior mesenteric artery (SMA) and the inferior mesenteric artery (IMA).
    • Located closer to the root of the mesentery than the marginal artery.
    • Less prominent than the marginal artery of Drummond.
  • Function: Provides collateral circulation between the middle colic branch of the SMA and the left colic branch of the IMA.
  • Surgical Implications:
    • Becomes crucial when there is occlusion or stenosis of either the SMA or IMA.
    • In situations like ischemic colitis, the Arc of Riolan can supply blood to the colon if one of the major arteries is compromised.
    • Recognizing this artery during surgery helps in preserving the collateral blood flow, especially in colon resections and during procedures that involve mobilization of the bowel.

Marginal Artery of Drummond

  • Anatomy: The Marginal Artery of Drummond is an important arterial arcade formed by anastomoses between branches of the SMA and IMA along the margin of the colon.
    • Runs along the inner border of the colon from the ileocolic artery to the sigmoid arteries.
    • It is generally more continuous and important for maintaining the blood supply to the colon.
  • Function: Provides a continuous arterial arcade that supplies the colon, maintaining circulation even if a major vessel like the SMA or IMA is occluded.
  • Surgical Implications:
    • Crucial in colorectal surgeries such as colectomies and anterior resections.
    • Preserving the marginal artery is essential to prevent ischemia in the bowel, particularly during extensive colonic mobilization or resection.
    • During a left hemicolectomy, for instance, the marginal artery’s role in perfusion must be assessed to avoid postoperative ischemia.
    • Ischemic colitis can result from disruption of this arterial supply, making it important for surgeons to ensure adequate blood flow through the marginal artery.

Arc of Riolan vs. Marginal Artery of Drummond

  • The Arc of Riolan lies deeper and is less frequently encountered than the Marginal Artery of Drummond.
  • Both arteries serve as collaterals between the SMA and IMA, but the marginal artery provides a more continuous and accessible arcade along the colon.

Key Points to Remember for MCQs:

  • Arc of Riolan is an intermittent collateral between the SMA and IMA, also called the Meandering Artery of Moskowitz.
  • Marginal Artery of Drummond forms a continuous arcade along the colon and is critical during colon resections to prevent ischemia.
  • Both the Arc of Riolan and the Marginal Artery are involved in providing collateral circulation in the event of SMA or IMA occlusion.
  • In surgery, preserving the marginal artery is crucial to avoid ischemic colitis, especially in procedures involving the colon.

These anatomical considerations are essential during surgeries such as colectomies, bowel resections, and vascular surgeries, ensuring the maintenance of adequate blood supply to prevent postoperative complications like bowel necrosis.