What clinical circumstances predispose to ischemic bowel disease?
Occlusive Mesenteric Ischemia
• Embolus: cardiac arrhythmias, valvular heart disease, myocardial infarction, mural thrombus, atrial myxoma, angiography, trauma
• Thrombosis: atherosclerosis, hypercoagulable states (e.g., pregnancy, hyperhomocysteinemia, antiphospholipid syndrome, birth control pills, neoplasms, polycythemia vera, essential thrombocytosis, and paroxysmal nocturnal hemoglobinuria), vascular aneurysms or dissections, vasculitides
Nonocclusive Mesenteric Ischemia
• Cardiac arrhythmias, hypoperfusion (cardiogenic shock, hypovolemia, sepsis), and vasoconstricting drugs (digoxin, cocaine)
• Hypercoagulable states (arterial causes, plus deficiencies of factor V Leiden, protein C and S, or antithrombin III), congestive heart failure, shock, portal hypertension, hepatic vein thrombosis (Budd-Chiari syndrome), malignancy, trauma, sclerotherapy, peritonitis, diverticulitis, pancreatitis, inflammatory bowel disease, intestinal obstruction, postoperative states, trauma