REMOVAL OF GRANULATIONS FROM THE TYMPANIC CAVITY
Indications. Granulations should always be removed if conservative treatment fails.
Operations. (a) Cauterizing; (b) Curetting. The former method is employed when the granulations are very small and localized; the latter when they are multiple and larger.
Cauterization. The tympanic cavity is cleansed and rendered anæsthetic (see [p. 310]). The auditory canal and tympanic cavity are then carefully dried. This is of importance in order to prevent scalding of the surrounding tissues during the act of cauterization. The ordinary electric cautery is used; only a weak current is necessary as the point of the cautery, of necessity, is very small. Under good illumination, the cautery is inserted cold along the auditory canal until it just touches the granulation. The circuit is then closed, and on the point of the cautery becoming white-hot, it is pressed against the granulation and then rapidly withdrawn from the ear. The current should not be shut off until the cautery is withdrawn, otherwise it will adhere, on cooling, to the tissues with which it is in contact, and on withdrawal will cause bleeding.
Instead of the electric cautery, the granulations may be touched with a bead of chromic acid fused on to a probe, or with a saturated solution of trichloracetic acid. The galvano-cautery has the greatest effect. Chromic acid has the disadvantage that unless it is very accurately applied it tends to affect a larger area than was possibly intended. Trichloracetic acid, although more localized in effect, is not so potent.
After-treatment consists in blowing in a slight amount of boric acid powder and keeping the ear dry.
Curetting. This is performed by means of small ring-knives ([Fig. 178]) or sharp spoons. They vary in size, and are either straight or bent in different directions to the shaft of the instrument. The instrument selected depends on the position and size of the granulation.
To minimize the hæmorrhage, adrenalin may be added to the cocaine solution. The curette is made to encircle the granulation and cuts through its attachment with a firm movement, limited to the area of the granulation. Curetting should not be done in a haphazard fashion, but deliberately under good illumination. If bleeding occurs it must be arrested before further curetting takes place.
After-treatment. The ear is syringed out to remove any fragments of granulation tissue or blood-clot. It is then dried and a strip of sterilized gauze inserted. After twenty-four hours this is removed and drops of rectified spirits, if necessary containing ten grains of boric acid or a drachm of the perchloride of mercury lotion to the ounce, may be instilled into the ear three or four times a day.
Dangers. With due care none should occur. The following mishaps, however, have occurred from too violent curetting: (1) Injury or displacement of the ossicles; (2) internal-ear suppuration from dislodging of the stapes or injury to the promontory; (3) facial paralysis; (4) meningitis from injury to the tegmen tympani; (5) acute inflammation of the mastoid process.