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': 'Vascular inflow occlusion of the liver is by - \nSelect and explain. \nA. Clamping the hepatic artery, B. Occluding the portal vein, C. Clamping the hepatic veins, D. The Pringle manoeuvre', 'role': 'user'}, {'content': 'Answer: D \nExplanation: • Total clamping of the hepatic pedicle, by placing an atraumatic clamp across the foramen of Winslow.\n• Appropriate-sized vascular clamp or loop snare easily controls hemorrhage from either the portal vein or the hepatic arteries.\n• Inflow occlusion durations of up to 30 minutes can be tolerated safely in cirrhotic livers and possibly up to 60 minutes in early disease.\n• If prolonged occlusion is required, intermittent clamping can be used with repeated clampings of 10-20 minutes duration, each followed by 5 minutes declamping.', 'role': 'assistant'}]