“…otomy with aspiration, with or without insertion of aerating tubes (Richards et ai, \9 1 l , Shah, 1971 ;Mawson anti Fagan, 1972), antibiotics (Coffey et ai, 1967), instillation of chymotrypsin {Mawson, 1967 ;Mawson and Fagan, 1972), steroids (Archard, 1967) or urea {Bauer, 1968, irradiation of the tubal entrance {Dawes, 1970; Grahne, 1964) and mastoidectomy {Grahne, 1964;Wilson, 1973) have all been used.…”