On the other hand, if the wound has been left open on account of bone disease involving the inner wall of the tympanic cavity or region of the Eustachian tube, the packing should be continued through the posterior opening until the patches of carious or necrosed bone heal or are exfoliated. In these cases the granulation tissue tends to become fibrous in character in consequence of the necessary curettings, and eventually to form a thickened pad covering the inner wall.
After complete healing has taken place, the patient, before being dismissed, should be warned to visit the surgeon at least once in three months. Owing to the large cavity being lined with epithelium, desquamation takes place to a greater or lesser extent, so that the wound cavity may gradually become filled with masses of epithelial débris or cerumen. In consequence the cavity may become septic, and on removal of the epithelial débris underlying ulceration may be found. This can usually be cured by aseptic treatment, but if granulations have already occurred, curetting and the application of trichloracetic and chromic acid may be necessary.
DIFFICULTIES AND DANGERS OF THE OPERATION
Anatomical difficulties. The chief difficulties are due to a middle fossa overlapping the antral cavity, a lateral sinus projecting far forwards and lying superficially, and a sclerosed mastoid having no landmarks to indicate the way into the antrum. Unfortunately these conditions are frequently associated.
Formerly it was advised that it was wiser not to proceed further if the antral cavity could not be discovered after chiselling to a depth of three-quarters of an inch. This advice, however, is no longer reliable, as by the combination of the Stacke, Wolf, or Küster-Bergmann method any anatomical difficulties should certainly be overcome.
An inexperienced operator may mistake a large mastoid cell for the antrum and in this way may get into difficulties. The opening into the antrum, however, can always be identified by passing a bent malleable silver probe in an inward and forward direction into the aditus. If only a large cell has been opened, the probe will show that it is a limited cavity.
Hæmorrhage. In the majority of cases this is more of an inconvenience than a danger, being chiefly due to a general oozing from the soft tissues. It is, however, very necessary that the surgeon should have a clear view of the deeper parts whilst operating. If he works blindly in a pool of blood he courts disaster.
The hæmorrhage is best prevented by first curetting away any granulation tissue and then packing the cavity firmly with a strip of gauze. If this be not sufficient, it may be again packed with gauze containing adrenalin solution. It will repay the surgeon to have a good assistant to keep the field of operation dry. Troublesome bleeding, coming from a small vessel in the bone, may be arrested by the local application of a small fragment of Horsley’s sterilized wax (see Vol. I, p. 437).
Wound of the lateral sinus. This is a serious matter for two reasons: firstly, it may prevent completion of the operation; and secondly, it may lead to infection of the sinus.