Part 55 (1/2)

Further treatment consists in keeping the ear clean and dry. For the first few days it should be syringed daily, dried, and spirit drops instilled. As the secretion becomes less the syringing should be diminished. If the perforation be large, instead of instilling drops, some finely powdered boric acid may be puffed in.

=Other methods of removal.= These are not recommended, but merely mentioned for the sake of completeness.

_By forceps._ The rough and ready method of extracting a polypus forcibly from the ear by means of forceps, although practised formerly, has now been discarded as being unsurgical and dangerous.

_Ligation._ The operation consisted in pa.s.sing a snare over the polypus and grasping it tightly as near to its base as possible. The snare was then twisted round its axis in order to tighten the loop further and so obliterate the blood-supply of the growth, the wire of the snare being afterwards cut through with pliers and the snare withdrawn. After a few days the polypus became gangrenous from want of blood-supply, and separated from its deep attachments.

_Curetting._ This method, which should only be made use of in the case of small multiple polypi within the tympanic cavity, will be considered when discussing the treatment of granulations within the middle ear (see p. 398).

=Dangers.= Haemorrhage is seldom profuse, but if it is, it can always be arrested by packing the meatus with cocaine and adrenalin solution.

[Ill.u.s.tration: FIG. 184. WILDE'S SNARE GRIPPING THE NECK OF POLYPUS.

(_Semi-diagrammatic._)]

[Ill.u.s.tration: FIG. 185. POLYPUS ARISING FROM THE ATTIC REGION. The snare is in position for the extraction of the polypus.

(_Semi-diagrammatic._)]

The chief dangers are injury to the contents of the tympanic cavity, such as dislocation or removal of the ossicles; or subsequent meningitis. These mishaps are usually the result of forcible extraction, or of blindly curetting the ear after this has been done. Meningitis, however, has been known to occur, in spite of every precaution being taken, if, owing to caries of the tegmen tympani, the polypus has its origin from the dura mater of the middle fossa.

=Prognosis.= If the polypus be single and of recent origin, the result probably of acute inflammation of the middle ear, its removal may cause complete recovery and cessation of the middle-ear suppuration.

In the case, however, of multiple polypi a.s.sociated with chronic middle-ear suppuration and usually signifying underlying bone disease, recurrences may be frequent and further operations may become necessary.

It may here be emphasized that a polypus in itself is not a disease, but merely a symptom of disease.

After removal of a large polypus, the patient should always be kept under observation for a day or two in case of symptoms of acute inflammation of the mastoid process arising and necessitating further operation.

CHAPTER III

OPERATIONS UPON THE TYMPANIC MEMBRANE AND WITHIN THE TYMPANIC CAVITY

SURGICAL ANATOMY OF THE TYMPANUM

=The tympanic membrane.= The chief points to notice when operating on the tympanic membrane are its inclination and its relation to the inner wall of the tympanic cavity.

The normal membrane is inclined obliquely downwards and forwards so that it forms an obtuse angle of 140 degrees with the roof and an acute angle of 27 degrees with the floor of the external meatus. In infants the inclination is even greater.

Its relation to the tympanic cavity varies in its different parts. It lies nearest to the inner wall in the region of the umbo, being only 2 millimetres distant from the promontory, and is furthest from it in the posterior quadrant.

Running backwards, just below the posterior fold, is the chorda tympani nerve, which may be cut through in the act of paracentesis and in division of the posterior fold.

=The tympanic cavity.= For the purpose of description the portion of the tympanic cavity above the level of the tympanic membrane is known as the _attic_ or _epitympanic cavity_; whilst the part below its level is called the _cellar_ or _hypotympanic cavity_ (Fig. 186).

The =attic= contains the head of the malleus and the body and short process of the incus, and communicates posteriorly with the antrum by a variable sized opening--the aditus. Its roof, the tegmen tympani, a plate of bone frequently of extreme thinness, separates the cavity of the middle ear from the middle fossa of the cranium. The facial ca.n.a.l extends backwards along the inner and upper border of the tympanic cavity, pa.s.sing above the vestibule and the fenestra ovalis to curve downwards posteriorly beneath the external semicircular ca.n.a.l, which at this point forms the inner and inferior boundary of the aditus.

The =ossicles= form a movable chain fixed at three points: namely, the attachment of the handle of the malleus to the tympanic membrane; the posterior ligament of the incus, a feeble structure, binding its short process to the entrance of the antrum; and the strong annular ligament connecting the footplate of the stapes to the margins of the fenestra ovalis.