Fenestration operation; a clinical study of the permanence of its results.

T HE fene.stra:tion operati?n for re toring hearmg m otosclerosIs rests upon a very simple principle: the creation of a new fistula, or window (fenestra) into the labyrinth to re-establish the passage of sound vibrations from the tympanic membrane to the cochlea. This communication is concerned with a clinical study of the permanence of the fistula, and the hearing improvement after the fenestration operation based on a sevenyear experience with 800 consecutive operations. The history of the fenestration operation is the story of the search for a method of making a labyrinthine fis tula that would remain open. The early operations of Passow (1896), Jenkins (1912), Barany (1916), and Holmgren (19161924) invariably failed because new bone formation always closed the fistula with loss of the hearing improvement a few weeks or months after operation. That we are now able to create a fistula in the bone of the labyrinthine capsule 'that will usually remain open is one of the achievements of modern surgery. In common with many scientific discoveries, the fenestration operation as it is now done represents the combined contributions of a number of different individuals, rather than the work of one person. Sourdille (1) in 1924 was the first to create a labyrinthine fistula which in at least some cases remained open for periods exceeding five years. He accomplished this by a series of three or four operations which consisted essentially in making a fistula into the horizontal semi-circular canal, and in covering it with a plastic skin flap attached to the drum membrane. In 1938 Lempert (2) combined Sourdille's series of operations into a single one-stage technic, and again was able to obtain a permanently open fistula with a maintained hearing