CHAPTER I

EXAMINATION OF THE EAR: GENERAL CONSIDERATIONS WITH REGARD TO OPERATIONS

In order to perform successfully the various operations upon the ear, it is essential that the surgeon should be familiar with the technique of its examination, which, for the sake of convenience, will first be briefly described.

EXAMINATION OF THE EAR

For this purpose it is necessary to make use of certain instruments in order to obtain a clear view of the deeper parts of the auditory canal and tympanic membrane. Most important amongst these are the following:--

=Mirror.= A head-mirror, such as the ordinary laryngological mirror with a focus of eight inches, is to be preferred to the hand-mirror, as it leaves both hands free for manipulation.

=Sources of illumination.= Although the light reflected from the sky on a bright cloudless day is excellent, it can seldom be made use of, and so for practical purposes the source of light is usually artificial. It is wiser always to use the same kind of light--for instance, electric--as in this way a more accurate comparison can be made of the various pathological conditions seen on examination. In the consulting room, the lamp recommended by Dr. Greville Macdonald, furnished either with a thirty-two candle-power frosted burner or with a Nernst light, is most suitable. As a portable lamp, it is useful to have an electric bull’s-eye lamp, run off from a dry-celled battery: it can be held in the position of the ordinary lamp, the light being reflected into the ear by means of the head mirror. The ordinary surgical head-lamp, although not well adapted for inspection of the deeper parts of the auditory canal, is eminently suited for obtaining good illumination during the performance of the mastoid operations; or in its stead a head-mirror with lamp attached may be used, as recommended by Clar (Fig. 171).

=Aural specula.= Of the various aural specula employed, Gruber’s is very good (Fig. 172). A special speculum in which a portion has been removed from the narrow end is sometimes useful in order to facilitate operative procedures within the external meatus.

=Forceps.= The best are angular spring forceps with bulbous points (Fig. 173).

=Position of the patient.= The patient should sit upright in a chair with the side to be examined turned towards the surgeon. To prevent movement, the head should be supported by an assistant or by a head-rest fixed to the back of the chair. The lamp is placed a little behind and to the left of the patient’s head, on a level with the head of the examiner.

=Technique of examination.= To convert the external meatus into a straight canal, the auricle has to be pulled backwards and downwards in an infant, backwards in a child, and backwards and upwards in an adult. The speculum should be warmed and inserted gently into the meatus by the thumb and index-finger of the left hand, whilst the pinna is held between and pulled back by the second and third fingers (Fig. 174). This leaves the right hand free for manipulation. The largest possible speculum should be used, in order to give the maximum amount of room and illumination. It should only be introduced into the meatus as far as the adaptable cartilaginous portion permits--about half an inch in the adult--and not forced into the bony portion. The utmost gentleness is essential in order to obtain the confidence of the patient; this is absolutely necessary for the performance of the various small operations upon the auditory canal and tympanic cavity under local anæsthesia.

=Method of cleansing the ear.= Except when the auditory canal is completely blocked by inspissated pus, cerumen, or epithelial débris, it is sufficient to mop out the ear with small pledgets of cotton-wool. To prevent injury to the walls of the meatus and to the tympanic membrane, the pledget is held between the blades of the forceps in such a fashion that it partially projects beyond its points (Fig. 175). The forceps is passed through the lumen of the speculum along the auditory canal and then quickly withdrawn. This is repeated with fresh pledgets until the meatus is cleansed. If there is much purulent discharge, only a brief moment may be given (after the withdrawal of the forceps) in which to inspect the deeper parts. Such a view, however, should always be obtained in order to form an accurate diagnosis. If this method fails to cleanse the ear, syringing becomes necessary.

=Technique of syringing.= The patient should be sitting down, as syringing may cause giddiness. The fluid should be aseptic, and at a temperature of 100° F. The patient’s head is inclined to the affected side, and the auricle is pulled upwards or backwards. The syringe is inserted a short distance within the meatus, and applied to the upper posterior wall so that the stream of lotion flows along the roof of the canal to the drum, and returns along the floor, thus washing out the contents. The best syringe is one with a metal plunger, as it can be easily sterilized. After syringing, the auditory canal should be dried and again inspected. If the inspissated pus or epithelial débris cannot be removed by simple syringing, an ear-bath of warm hydrogen peroxide (10 vols. %) should be given, and the ear again syringed after ten minutes.

=Syringing out of the attic.= In certain cases of chronic attic suppuration, it is advisable to syringe out the attic. For this a special syringe is necessary. It consists of a fine canula whose point is turned up almost at right angles to its shaft (known as Hartmann’s canula), to which is fitted a piece of india-rubber tubing and a ball syringe. Milligan’s modification of this instrument is now generally used, as it permits of the canula being held in the hand, and instead of having a ball syringe, is connected by rubber tubing to a small irrigator (Fig. 176).

The patient sits upright in a chair in the ordinary position for examination of the ear; a speculum is inserted into the meatus, and held in position with the left hand; the canula, together with the ball syringe (if Hartmann’s is used), is held in the right hand. Under good illumination the canula is passed inwards along the auditory canal, and its point inserted through the perforation. By gently pressing on the syringe, the fluid is forced into the attic, which is thus washed out.

With Milligan’s instrument, the irrigator is fixed about two feet above the level of the ear. While the canula is being inserted, the escape of lotion is prevented by compressing the tube against the shaft of the instrument by means of the thumb. After the canula has been inserted into the opening, relaxation of this pressure permits of flow of the lotion. Milligan’s method is better than Hartmann’s, as the surgeon has more control over the instrument. Pain due to the introduction of the canula may be greatly minimized by previously inserting within the margins of the perforation either a pledget of cotton-wool soaked in a saturated solution of cocaine, or a crystal of cocaine.

After the cavity has been thoroughly washed out, the auditory canal is carefully dried as a final step, gentle inflation by Politzer’s method may be performed in order to expel any fluid still remaining within the attic.

GENERAL CONSIDERATIONS WITH REGARD TO OPERATIONS

In this connexion two points must be borne in mind: (1) The surgeon must have a good view of the part operated upon. For this reason when operating upon the auditory canal, the tympanic membrane, and tympanic cavity, he will usually require to work by reflected light.

(2) There must be no movement of the patient’s head during the operation. If the operation is performed under a local anæsthetic, it is therefore very important that the patient’s head should be kept fixed by means of an assistant.

=Preliminary surgical toilet.= If there be no existing suppuration, the ear should be cleansed, some twelve hours before the operation, by first giving an ear-bath of hydrogen peroxide lotion. This is done by making the patient incline the head to the opposite side so that the affected ear is uppermost. The warm solution is then poured into the meatus. After ten minutes the ear is syringed out with a 1 in 5,000 aqueous solution of biniodide of mercury, and a strip of sterilized gauze is then inserted into the auditory canal. The auricle and surrounding parts should also be surgically cleansed, and afterwards protected by a simple aseptic compress. If, as in furunculosis of the external meatus, syringing or cleansing of the ear is very painful, drops of a 10% solution of carbolic acid in glycerine may be instilled frequently into the meatus instead. If there is an existing otorrhœa, it is obviously impossible to render the field of operation absolutely aseptic. The ear, however, should be cleansed, but the auditory canal should not be plugged with gauze. The existence of a purulent discharge is no excuse for lack of cleanliness. Failure of such precautions may lead to disaster; for example, to perichondritis of the auricle as a sequel of the mastoid operation.

Before the actual operation takes place, if necessary after the anæsthetic has been given, the ear and surrounding parts should again be carefully cleansed, and the auditory canal syringed out with biniodide of mercury solution.

In intrameatal operations the head should be wrapped in a sterilized towel, and a square of sterilized lint, having an aperture in the centre so as to expose only the auricle and meatus, should be placed over the side of the head and face. In operations on the mastoid process, and in those involving a post-auricular incision, the head should also be shaved for at least two or three inches beyond the region of the ear.

=Anæsthesia.= Both local and general anæsthesia are used. Unless contra-indicated for some special reason, and unless the operation is a very trivial one, it is wiser to give a _general anæsthetic_. Of these, chloroform is the most suitable in adults and infants, and the A. C. E. mixture in children. Ether, although it may be safer, is frequently a source of annoyance to the operator, as it tends to increase the hæmorrhage.

In order to produce _local anæsthesia_ two methods may be employed: (1) The instillation of fluids into the meatus; (2) subcutaneous injection of fluids beneath the lining membrane of the meatus and into the surrounding parts of the auricle.

The solution usually employed is a sterilized aqueous solution of cocaine hydrochloride in varying strengths up to 20%, to which may be added equal parts of 1 in 1,000 adrenalin chloride solution; the latter not only increases its analgesic properties, but also acts as a powerful hæmostatic.

_Instillation._ As the auditory canal and the tympanic membrane are lined with epithelium which is very resistant to the absorption of fluids, complete anæsthesia is almost impossible to obtain. This method, therefore, is practically limited to such trivial operations as the curetting away or snaring off of granulations or polypi from the external or middle ear. To render anæsthesia more complete, the affected part may be finally rubbed over with a crystal of solid cocaine hydrochloride just before the operation--is begun. On the other hand, if the raw surface is large--for example, the wound left after a recently performed complete mastoid operation--the cocaine employed should not be stronger than a 5% solution in order to minimize the risk of poisoning. Gray of Glasgow has suggested, as a more penetrating anodyne solution, a mixture consisting of a 10% solution of cocaine hydrochloride in equal parts of aniline oil and absolute alcohol, a solution which he especially advocates in order to produce anæsthesia of the tympanic membrane before doing paracentesis.

_Subcutaneous injection._ This is a modification of Schleich’s method, and was first introduced by Neumann of Vienna. It consists in injecting a very weak solution of cocaine and adrenalin chloride subcutaneously beneath the periosteum lining the auditory canal. By this method even the complete mastoid operation has been performed, and in certain clinics it is used continually in the minor operations of paracentesis of the tympanic membrane, division of intratympanic adhesions, extraction of polypi, and ossiculectomy. A solution of beta-eucaine or novocaine may be used in preference to cocaine, as being less dangerous. According to Neumann, three solutions are necessary: (_a_) a 1 in 2,000 solution of adrenalin chloride containing a 1% solution of beta-eucaine; (_b_) a 1 in 3,000 solution of adrenalin chloride containing a 1% solution of cocaine; (_c_) a 20% solution of cocaine.

The syringe for injecting the solution has a capacity of I cubic centimetre, and for convenience its needle is fixed at an obtuse angle to the body of the syringe (Fig. 177). The technique of the injection depends on whether the operation is to be limited to the auditory canal and tympanic cavity, or is to involve the mastoid process.

If the complete mastoid operation is going to be performed, the needle of the syringe, now filled with the eucaine solution, is thrust through the skin about the middle point of the mastoid process, and a few drops of the solution are injected. The needle is then forced upwards towards the temporal ridge, at the same time being thrust in deeply until it touches the bone, so that a syringeful of the solution is injected beneath the periosteum. The needle is then withdrawn and reinserted at the same point, but in a backward direction, the solution being injected along the posterior portion of the mastoid process; in a similar manner the solution is injected downwards towards the tip of the mastoid. The ear being now pulled well forward, the needle is made to pierce the fold between the auricle and the mastoid process, just above the posterior ligament, and is pushed inwards between the anterior border of the mastoid process and the cartilage of the meatus, and a further syringeful of the solution is injected. A large speculum is now inserted into the ear, so that by pressing it against the wall of the meatus the skin, at the termination of the cartilaginous portion, is made to project in folds. The needle of the syringe, filled with cocaine solution, is pushed into this fold, and a few drops of the solution injected. By degrees the needle is still further pushed inwards, keeping it in close contact with the bony wall so that the fluid is injected beneath the periosteum. If the injection has been successful, a white bulging of the superior wall of the auditory canal will be noticed. To render anæsthesia complete, further injections may be made into the inferior and anterior walls of the auditory canal. Finally, a pledget of cotton-wool soaked in a 20% solution of cocaine is pushed into the tympanic cavity.

In the case of simple opening of the mastoid, subcutaneous injections into the auditory canal are not necessary. On the other hand, if the operation is limited to the auditory canal and tympanic cavity, the injections into the mastoid process are not required, but a primary injection of a small quantity of eucaine solution into the auriculo-mastoid fold considerably diminishes the pain produced during the act of injection into the auditory canal. Fifteen minutes should be allowed to elapse before the operation is begun. The anæsthesia lasts about half an hour.

_Difficulties._ It is by no means easy to inject fluid beneath the periosteum of the auditory canal, owing to its close adherence to the bone. The needle by mistake may repierce the skin at a point farther in, so that the fluid, instead of being injected beneath the periosteum, is injected into the auditory canal itself. In these cases anæsthesia will not be obtained, and the operator may possibly blame the principle of subcutaneous injection, rather than his own faulty technique.

In favour of subcutaneous injection it is urged that most of the minor operations within the tympanic cavity, including ossiculectomy, may be performed with the patient sitting up in the chair in the consulting room, and further, that the patient can afterwards go home; that the operation is rendered more easy owing to there being practically no bleeding; and that in the case of the more severe operations, such as opening of the mastoid antrum, the surgeon, in a case of emergency, may make use of this method if he cannot possibly obtain the services of an anæsthetist.

Against subcutaneous injection is the pain of the injection, which may be so great that the patient will not submit to it, and in consequence the proposed operation may have to be postponed.

In the case of the mastoid operation, it is difficult to believe that local anæsthesia, however efficient, will be looked upon with favour either by the surgeon or by the patient, except when a general anæsthetic is absolutely contra-indicated. The discomfort produced by retraction of the parts, the jarring caused by chiselling, and the consciousness of what is taking place, are far more unpleasant and more of a shock to the patient, than a general anæsthetic carefully given. Further, it is not always possible to foretell the extent of the operation, and if repeated injections become necessary, there is danger of eucaine or cocaine poisoning being produced.

=Position of the patient and the surgeon=

1. In the minor operations the patient may be operated on whilst in the sitting posture, whether a local anæsthetic or a general one of gas and oxygen is employed. The relative positions of the patient and the surgeon are then the same as for the ordinary routine examination of the ear. Special care, however, should be taken that the patient’s head is supported by the anæsthetist or assistant in order to prevent involuntary movements.

2. If the patient is operated on in the recumbent position, the head may rest comfortably on an ordinary pillow, but if chiselling is going to take place, the best support is a loosely filled sand-bag. The head should be turned towards the opposite side so that the affected ear is uppermost, and the surgeon stands at the side to be operated on. The lamp, the source of reflected light, should be held about six inches above the patient’s shoulder on the opposite side.