Nonocclusive mesenteric ischemia (NOMI)

Abstract

Acute mesenteric ischemia remains a major cause of intra-abdomi-nal catastrophe and mortality in the vascular patient population. Inter-ruption or diminution of blood flow to the small intestine and right colon principally results from mechanical obstruction of the superior mesenteric artery (SMA) by embolus or thrombosis or from primary splanchnic vasoconstriction, a clinical entity known as nonocclusive mes-enteric ischemia (NOMI). It estimated that NOMI is the underlying cause in at least 20% to 30% of cases of acute mesenteric ischemia and, unfortunately, results in mortality in up to 70% of afflicted patients.2, 18* 30 This dismal prognosis is usually attributed to difficulty in antemortem diagnosis and an incom-plete understanding of its pathophysiologic mechanism. Furthermore, the clinical presentation of NOMI is frequently associated with other life-threatening disorders in patients sustained by advanced mechanical and pharmacologic life support. Liberal use of arteriography in patients suspected to have NOMI offers the best chance for early diagnosis and treatment prior to bowel infarction. The purpose of this article is to summarize the current knowledge of the pathophysiology of NOMI and discuss the diagnostic and treatment modalities that may enhance survival in these critically ill patients. PATHOPHYSIOLOGY