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: Unknown
[{'content': 'The ideal material used for Femoro-popliteal shunt is: \nSelect and explain. \nA. PTFE, B. Reverse saphenous vein, C. Polypropylene, D. Dacron', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ref. API Textbook of Medicine. Pg. 758\n\xa0\nThe most ideal material used for femoro-popliteal shunt is an existing piece of vein taken from the same leg of the patient (reverse saphenous vein from this options).\n\nMan made graft materials such as PTFE or Dacron or polyproplene are most likely to become narrowed again ,but they are still effective .\nAutologous saphenous vein achieves superior patency rates to prosthetic materials especially in femoro-distal bypass.\nInsitu and reversed vein graft bypasses perform equally well and the choice of technique should be based upon anatomical considerations that are specific to individual patients', 'role': 'assistant'}]