Most common arterial involvement causing ischemia of intestine is:

Ans: A (Superior mesenteric artery thrombosis) Ref: Schwartz Textbook of Surgery, 10th edition, pg: 860; Mastery of Vascular and Endovascular Surgery - Gerald B. Zelenock - 2006, pg: 294 and Essentials of General Surgery, Peter F. Lawrence, 2006, pg: 459Explanation:"The SMA is the most commonly involved vessel in acute mesenteric ischemiaRef: Mastery of Vascular and Endovascular Surgery"Embolization to the superior mesenteric artery accounts for approximately 50% of ail cases of acute mesenteric ischemia Ref: Essentials of General SurgerySuperior Mesenteric Artery EmbolusMost common cause of mesenteric ischemia (40 to 50% of cases).The prognosis is poor (70% mortality).Sudden embolus with no time for collaterals to form.Presents with abdominal pain out of proportion to examination findings.Risk Factors:o Arrhythmias (atrial fibrillation),o Post-myocardial infarction with mural thrombi,o Valvular heart disease.o Structural heart defects.Superior Mesenteric Artery ThrombosisAccounts for 25 to 30% of mesenteric ischemia cases.Has worst prognosis with a mortality of 90%.Occurs near the origin of the SMA.Causes enormous amount of bowel necrosis.Most patients have a history of chronic mesenteric ischemia with vague and insidious symptoms such as:o Weight loss.o Abdominal angina (abdominal pain after meals),o Diarrhea,o Fear of food.Risk Factors:o Systemic atherosclerosis,o Old age.Angiography is the gold standard for mesenteric ischemia allowing for diagnosis and therapy.