Intestinal Ischemia

Definition and EtiologyTop

Intestinal ischemia refers to reversible and irreversible bowel injury that results from a decrease in blood flow to the small or large intestine. Any process that reduces intestinal blood flow, with or without subsequent reperfusion injury, can cause intestinal ischemia. Causes may be occlusive (arterial embolism, arterial thrombosis, or venous thrombosis) or nonocclusive (eg, due to a low-flow state or vasospasm). Intestinal ischemia varies widely in presentation and outcome depending on the underlying pathophysiology, time course of disease, degree of blood flow compromise, presence of collateralization, and segment of the bowel affected. Serious consequences such as bowel infarction, perforation, sepsis, and death can occur.

There is variation in terminology in the literature that can cause confusion. In our chapters mesenteric ischemia refers to small bowel ischemia. Ischemic colitis and colonic ischemia refer to large bowel ischemia representing variable clinical presentations across the spectrum of severity of the disease. The terms intestinal ischemia and ischemic bowel can apply to either the small or large bowel.