This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ear, Subject name: ENT
A 30-year-old male is having attic cholesteatoma of left ear with lateral sinus thrombophlebitis. Which of the following will be the operation of choice? 
Select and explain. 
A. An intact canal wall mastoidectomy, B. Simple mastoidectomy with tympanoplasty, C. Canal wall down mastoidectomy, D. Mastoidectomy with cavity obliteration
C: Canal wall down mastoidectomy
Answer: C: Canal wall down mastoidectomy 
Explanation: Aim of surgery in middle ear infections is to make the ear safe. Since attic cholesteatoma in this case is complicated by lateral sinus thrombosis, modified radical mastoidectomy (canal wall down procedure) will be justified. In this case, the disease will be exteriorized so that the cavity could be subsequently examined and cleaned if cholesteatoma was left behind or recurs.Intact canal wall mastoidectomy and simple mastoidectomy are "canal wall up" procedures. Obliteration of mastoid cavity even after removal of cholesteatoma runs the risk of burying cholesteatoma and subsequent complications.