Indications. Operation is justifiable in the case of adhesion of the malleus to the promontory if the rest of the membrane is freely movable; if the membrane bulges outwards and there is temporary improvement in hearing on inflation; and if examination shows that the labyrinth is intact. This operation is all the more indicated if there is marked deafness on both sides: it should then be attempted on the worse side. If, however, the intratympanic adhesions are extensive, it is very doubtful whether an attempt to separate the free part of the membrane from the part adherent to the inner wall is worthy of consideration.
It must also be remembered that adhesions in the region of the stapes cannot be seen, unless a large perforation of the membrane already exists. Operation is then only justifiable as a last resource if there is extreme deafness accompanied by distressing subjective symptoms.
Operation. Unless the patient is very sensitive or nervous, local anæsthesia is sufficient. It is more convenient for the patient to be sitting up in a chair than to be in the recumbent position. The surgeon works by reflected light. Before the operation is begun, the ear must be surgically cleansed and carefully dried.
Fig. 191. Cutting through Intratympanic Adhesions. The malleus is adherent to the promontory. A, Surface view; B, Vertical section. a, Handle of the malleus; b, Membrane adherent to the promontory; c, Line of incision to cut through the membrane.
Fig. 192. Free Edge of Tympanic Membrane cut through. A, Surface view; B, Vertical section. a, Malleus adherent; b, Membrane adherent; c, Free edge of membrane; d, Spatula freeing membrane.
(i) Adhesion of the handle of the malleus to the promontory. With a paracentesis knife the membrane is incised round the handle of the malleus (Fig. 191). A small sickle-shaped knife, fixed at right angles to its shaft, is then inserted through the incision (in front of or behind the malleus as may be most convenient to the operator) and is made to cut through the adhesions between the malleus and the promontory (Fig. 192). In order to make sure that this has been accomplished, a small ring-knife, such as is used in the operation of ossiculectomy, is passed round the tip of the malleus, between it and the inner wall of the promontory, and slight traction is then exerted in order to pull the handle of the malleus outwards from the inner wall.
Provided asepsis has been maintained, this small operation seldom gives rise to any inflammatory reaction. The after-treatment consists in inserting a strip of gauze into the auditory canal; if it becomes moist with secretion, it should be changed.