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What is Most common cause uf acute mesenteric ischemia is: and explain in detail?
Ans. c. Embolism Most common cause of acute mesenteric ischemia is embolism.Acute Mesenteric Ischemia1. Emboli (50%)Q:- Arrhythmia, valvular diseasemyocardial infarction- Hypokinetic ventricular wall- Cardiac aneurysm, aortic atherosclerotic disease2. Thrombosis <25%): Atherosclerotic disease3. Nonocclusive (5-15%):- Pancreatitis. heart failure, sepsis0- Cardiac bypass, burns. renal failure04. Venous occlusion:- Hypercoagulable state- Sepsis, compression, pregnancy, portal hypertension Embolic occlusionAcute thrombotic occlusionNon-occlusive mesenteric ischemia* Accounts for 40-50% of cases of AMI.* Most emboli are secondary to AFdeg* More than 50% of emboli lodge in the mid to distal segment of the SMAdeg.* Account for 25-35% of cases of AMI.* Occurs in conjunction with chronically diseased vessels* More insidious onset because of previously developed collateral circulation.* Accounts for 20% of cases of AMI* Occurs with patent mesenteric arteries* Splanchnic vasoconstriction0 is the underlying pathophysiologic process* Precipitated by hypoperfusion from medications, depressed cardiac output, or renal or hepatic disease0.Clinical Features:Early diagnosis is the key to successful management of AMIdeg.Most patients have nonspecific symptoms of abdominal pain0.Abdominal pain out of proportion to the findings on physical examination and persisting beyond 2 to 3 hours is the classic picture.* Diarrhea, nausea, vomiting, and anorexia can also be part of the initial symptom complex.* Melena or hematochezia in 15%. and occult fecal blood is found in half of the patients.* Leukocytosis is common.Diagnosis:* IOC in AMI is mesenteric arteriography0.* CT scan: Wall hyperdensity, absence of wall enhancement, wall thickening, bowel dilation, pneumatosis, gas in mesenteric vein branches and in portal vein branches.* Hemoconcentration. leukocytosis and metabolic acidosis is present.* Hyperkalemia and hyperphosphatemia in bowel infarction should be suspected.Treatment:* Effective management: Early diagnosis, aggressive resuscitation, early revascularization, and ongoing supportive care.* Mucosal layer is the most sensitive to ischemia, bacterial translocation should be anticipated and intravenous antibiotics used to treat the associated bacteremia.* Catheter-directed papaverine to reverse the severe mesenteric vasospasm0 is initiated early after arteriography.* Anticoagulation is given to prevent propagation0 of mesenteric thrombus.* In addition to aggressively correcting the low cardiac output, terminating vasoconstrictor use. and discontinuing digitalis preparations, intra-arterial papaverine infusion is the treatment of choice.* In the absence of peritonitis, supportive care with anticoagulation and continued papaverine infusion is recommended.* Evidence of peritonitis: Exploratory laparotomy, with conservative resection of necrotic bowel.