In chronic mesenteric ischemia, which arteries usually need to be at least partially obstructed to see symptoms?

In chronic mesenteric ischemia, symptoms typically arise when there is significant reduction in blood flow to the intestines, primarily due to stenosis or occlusion of the mesenteric arteries. The primary arteries involved are the celiac trunk, the superior mesenteric artery (SMA), and the inferior mesenteric artery (IMA).

To experience symptomatic chronic mesenteric ischemia, at least two of these three arteries usually need to be at least partially obstructed. This is because if only one artery is affected, collateral circulation from the other vessels can often compensate adequately, maintaining sufficient blood flow to the intestines. However, when two or more arteries are compromised, the collateral circulation may be insufficient, leading to inadequate perfusion of the bowel and manifesting as symptoms such as abdominal pain after eating, weight loss, and fear of eating due to pain.

This understanding highlights the importance of multiple artery involvement in the disease process, which is why the answer focuses on the necessity of at least two obstructed arteries to see clinically relevant symptoms.