This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'True about mesenteric vein thrombosisa) Peritoneal signs always presentb) Thrombobectomy is always donec) Heparin is givend) Surgery can lead to short bowel synd. \nSelect and explain. \nA. cd, B. bc, C. bd, D. ac', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Mesentric vein thrombosis is cause of mesenteric ischemia in 5 to 15% of cases (others are due to mesenteric artery emboli & thrombosis)\nMesenteric venous thrombosis is mostly associated with a hypercoagulable state (eg. Protein C, S deficiency, Antithrombosis III def., Pregnancy, Polycythemia vera, Malignancy)\nOther causes are\n\n\nAbdominal sepsis - pancreatitis, peritonitis, intrabdominal abscess\nProtal hypertension\nTrauma\n\nSymptoms and signs\n\nMVT may present in acute, subacute or chronic form.\nThe major presenting symptom is non specific abdominal pain, followed by diarrhoea and nausea and vomiting.\nOccult blood in stools is seen in about half of patients.\nSome patients may have lower GI bleeding. Rarely hematemesis may occur.\nPeritoneal signs are present in less than half of MVT patients.\n\nDiagnosis\n\nContrast enhanced CT scanning is the diagnostic study of choice.\n\nManagement\n\nPatients with MVT are given adequate fluid resuscitation and anticoagulated with heparin.\nUrgent laparotomy is indicated for patients with peritoneal findings\nNonviable bowel along with its mesentry is resected and primary anastomosis done. Viable but suspicious bowel is not resected, but a second look operation is recommended within 24 to 48 hrs.\nThrombectomy has not been proved to be successful. However, thrombectomy is indicated if a long segment of nonviable bowel is found and the angiogram or operative findings indicate complete thrombosis of SMV.\nNote that MVT is usually due to thrombosis of small peripheral venous branches. Thrombosis of SMV or IMV is not common.\nPatients without peritoneal sign can be managed on heparin, bowel rest and fluid resuscitation.\nHeparin is replaced with oral anticoagulants in 3 to 4 days and is usually continued lifelong.\nPrognosis is poor (mortality is as high as 50 %.)', 'role': 'assistant'}]