The ear and surrounding parts are surgically cleansed by the ordinary methods. The surgeon works by reflected light. The patient may be in either the sitting or the recumbent position, depending on whether a local or general anæsthetic is given. In the latter case the auditory canal should be filled with cocaine and adrenalin solution before the anæsthetic is administered in order to diminish bleeding as far as possible.
The ear having been dried, a conveniently large aural speculum is inserted, and with a tenotome or a furunculotome radiating incisions are made through the stricture. One of the small flaps thus made is grasped with a fine pair of tenaculum forceps, and the surgeon cuts through its base, keeping the knife as close as possible to the wall of the auditory canal. Each flap is treated in a similar fashion. Instead of making radiating incisions, the tissue forming the obstruction may be transfixed through its base, the knife being made to cut in a circular fashion right round the auditory canal, keeping as close as possible to its wall.
On completion of the operation, a piece of india-rubber tubing, of as large a size as possible, is inserted into the dilated canal. It should only be removed for the purpose of cleansing and should be at once reinserted. A silver canula, if necessary, can afterwards replace the india-rubber tubing. This canula may have to be worn for months.
This operation is often most unsatisfactory, as the stricture, instead of being annular as first supposed, may be found, on operation, to extend a considerable distance along the auditory canal and, in addition, to be partially due to a general thickening of the underlying bone.
Excision of the stricture. The auricle is reflected forward and the preliminary steps of the operation are performed as already described for removal of a deep-seated exostosis (see [p. 319]). The surgeon makes a transverse incision with a knife through the fibrous portion of the auditory canal, just external to the stricture, and carries it right round the meatus, thus separating the outer portion of the membranous from the bony canal. The fibrous portion is now pulled outwards by means of a retractor, and the thickened tissue, forming the stricture, is peeled off from the surrounding bony meatus with a small periosteal elevator and so removed. If the stenosis is partially due to thickening of the walls of the canal itself, it may also be necessary to chisel away a considerable portion of its upper posterior part. After completion of the operation a clear view of the tympanic membrane should be obtained.
In this operation a considerable portion of the bony canal is denuded of its epithelial lining membrane, so that there is a special tendency to the re-formation of cicatricial tissue. To prevent this taking place two methods may be employed:—(1) If much of the upper posterior wall of the bony meatus be removed, a post-meatal flap should be made and kept in position by means of a catgut suture carried through the skin behind the auricle. The formation of such a flap is described as a step in the complete mastoid operation (see [p. 401]).
(2) If no bone be removed, the membranous portion is replaced in situ, the posterior auricular wound closed, and as large an india-rubber tube as possible is inserted into the meatus. A week or ten days later, as soon as granulations begin to form, skin-grafting may be undertaken (see [p. 410]).
If grafting be not successful, the india-rubber tube or silver canula must be kept constantly within the meatus (only being removed for cleansing purposes) until healing takes place.
The complete mastoid operation is indicated in the case of stenosis occurring in chronic middle-ear suppuration if symptoms of retention of pus occur.
In acute middle-ear suppuration, however, every attempt should be made to avoid operation, as the lumen of the auditory canal may again become patent after the acute inflammation has subsided.