Part 52 (1/2)
REMOVAL OF EXOSTOSES FROM THE EXTERNAL MEATUS
=Indications.= The indications vary, depending on whether there is a coexisting middle-ear suppuration or not.
=If there be no middle-ear suppuration.= Operation is not urgent, but is justifiable under the following conditions:--
(i) _When one ear only is affected._ (_a_) If there be complete deafness due to obstruction of the auditory ca.n.a.l. The question of operation, however, should be decided by the patient, because it may be postponed indefinitely so long as no symptoms occur.
(_b_) If there be recurring attacks of discomfort or of pain in the ear as a result of eczema, of ot.i.tis externa, or of actual pressure of the growth itself. The patient may desire operation to obtain permanent relief.
(_c_) If there be deafness of the opposite side from other causes, and the presence of the exostoses is causing deafness of the functionally good ear.
(ii) _When both ears are affected._ In addition to the indications already given, operation is advisable on the worse side if there be almost complete obstruction on both sides, accompanied by recurrent attacks of deafness, owing to the narrowed pa.s.sage of the auditory ca.n.a.l becoming repeatedly blocked from acc.u.mulation of cerumen or epithelial debris.
_Operation is contra-indicated_ if previous examination indicates that the deafness is due to a chronic middle-ear catarrh or internal-ear disease, as in these cases restoration of hearing, which is the primary object of the operation, will be impossible.
=If middle-ear suppuration be present= operation is generally advisable.
(i) _In acute middle-ear suppuration_ operation is urgent if there are signs of retention of pus, _provided_ it is impossible to dilate the lumen of the auditory ca.n.a.l. Before resorting to operation an attempt should always first be made to obtain free drainage, as the obstruction may be due merely to inflammatory swelling of the tissues lining the auditory ca.n.a.l. With cessation of the acute inflammation, this swelling may subside and the lumen of the auditory ca.n.a.l again become patent; and if recovery with healing of the tympanic membrane takes place the hearing may again become normal, rendering the operation no longer necessary.
(ii) _In chronic middle-ear suppuration_ operation is always indicated if there are symptoms of retention of pus. It is also advisable as a prophylactic measure, although not urgent, even although no acute symptoms are present.
=Operation.= =When there is no middle-ear suppuration.=
The operation may be performed either (_a_) through the external meatus or (_b_) by reflecting the auricle forward by a post-auricular incision.
=Through the external meatus.= This method is only indicated if the exostosis is situated at the entrance of the meatus and is pedunculated.
A general anaesthetic is given, the patient being in the rec.u.mbent position. The surgeon works by reflected light. After the ear has been thoroughly cleansed a large-sized aural speculum is inserted into the meatus and the outlines of the exostosis are defined with a probe. A small gouge or chisel is used. It is inserted into the meatus in such a fas.h.i.+on that its point presses between the pedicle of the exostosis and the wall of the bony meatus. With successive sharp taps of the mallet, the gouge is made to cut through the pedicle, care being taken that the instrument is not driven in too deeply, on to the tympanic membrane.
The growth, which can now be felt to be movable within the meatus, can usually be removed by grasping it between the blades of forceps, or can be expelled by syringing the ear. After its removal the auditory ca.n.a.l should be plugged for a few minutes with a solution of cocaine and adrenalin chloride. This checks all haemorrhage, and at the same time enables the surgeon to get a good view of the deeper parts to see if further growths are situated more deeply within the meatus. Such growths, provided they are pedunculated and do not abut on the tympanic membrane, can sometimes also be removed by the same method; much depends on their shape and situation. If sessile or too deeply placed, the operation may have to be completed by reflecting forward the auricle.
Before terminating the operation a clear view of the tympanic membrane should always be obtained.
The meatus is finally syringed out with a 1 in 5,000 aqueous solution of biniodide of mercury and dried, a strip of sterilized gauze being inserted into the auditory ca.n.a.l. A simple dressing is then applied to the side of the head.
_Other methods of operation through the external meatus._
(_a_) Perforation of the exostosis, or enlargement of the small pa.s.sage existing between multiple exostoses, by means of the burr.
Although successful results have been recorded, this method is not advised, as cicatricial tissue almost invariably causes closure of the opening made. To keep the opening patent it is necessary to insert a small lead or silver canula, frequently a source of great discomfort.
(_b_) If the exostosis has a very fine pedicle, it may be possible to nip through its base with a pair of forceps, but it is not so sure a method as the employment of a gouge and mallet.
(_c_) Such methods as attempts to destroy the growth by means of the galvano-cautery or by the pressure of laminaria tents should be avoided; they are useless and unsurgical.
=By reflecting the auricle forward.= This is indicated if the exostoses are multiple, have a broad base, and are deeply situated.
The position of the patient, and the anaesthetic, are the same as in the previous operation. Reflected light may not be necessary.
The ear and the surrounding parts are carefully cleansed and the head is shaved for a short distance over and beyond the mastoid process. A curved incision is made _close behind_ the auricle (Fig. 226), beginning at the upper level of its attachment and extending downwards along the retro-auricular fold. The incision goes down to the bone. The auricle is reflected forward and the soft tissues are separated from the bone until Henle's spine and the posterior upper margin of the auditory ca.n.a.l are brought into view. Any bleeding, chiefly from branches of the posterior auricular artery, is at once arrested by pressure forceps, ligatures being afterwards applied. The a.s.sistant's duty is to hold the auricle well forward and at the same time to keep the wound dry by swabbing.