Middle ear effusions: a consideration of factors involved in their aetiology, maintenance and treatment

Although the treatment of chronic middle ear effusion in children by paracentesis and the insertion of a ventilator tube is popular, it is well recognized that this method does not always provide a cure. Failures are frequently attributed to premature extrusion of the tube. Success in designing a 'long-stay tube' will depend upon a better understanding of the pathogenesis of middle ear effusion. Some of the various factors considered responsible for the initiation and maintenance of middle ear effusion are discussed and the possible mechanisms of tube extrusion are considered.