A System of Operative Surgery Part 59

=Removal of the outer wall of the attic.= In the majority of cases of chronic middle-ear suppuration, it is advisable to remove the outer wall of the attic in addition to performing the simple operation of ossiculectomy. If granulations be present they should first be removed, in order to give a clear view of the inner wall of the tympanic cavity, which can usually be obtained, owing to the fact that a large perforation of the membrane is probably present. The malleus and incus are then removed.

[Ill.u.s.tration: FIG. 206. PFAU'S ATTIC PUNCH FORCEPS.]

To remove the outer wall of the attic a small but strong pair of punch-forceps is required (Fig. 206). The instrument is directed along the roof of the auditory ca.n.a.l, its cutting edge held upwards and the blades kept slightly open, until the outer blade is felt to pa.s.s over the outer wall of the attic. The handle is then depressed so that the end of the forceps is forced upwards and embraces the outer wall between its points (Fig. 207). This is confirmed by attempting to withdraw the forceps, which the outer bony wall of the attic will now prevent. The position of the forceps being a.s.sured, its blades are brought together by pressure on the handle, and in this manner a small portion of the bone is punched out. In this way the outer wall of the attic is gradually cut away in small fragments. Sometimes this is extremely easy, owing to the auditory ca.n.a.l being large and the outer wall of the attic being thin and easily cut through. In other cases, owing to the thickness of the bony walls or to the narrowness of the ca.n.a.l, it is extremely difficult. If the outer wall of the attic has been completely removed, a fine probe, whose point is bent upwards, can be inserted into the attic and then withdrawn without encountering any obstruction, owing to the roof of the attic and outer wall of the auditory ca.n.a.l being now continuous. In some cases this part of the operation may not be necessary, as the outer wall of the attic may have already disappeared as a result of the caries.

[Ill.u.s.tration: FIG. 207. REMOVAL OF OUTER ATTIC-WALL WITH FORCEPS. A, Outer attic-wall.]

Into the larger opening thus made, small curettes are pa.s.sed upwards and backwards and any granulations in the region of the aditus and entrance to the antrum are curetted away. Finally the cavity is thoroughly swabbed out with the pledgets of cotton-wool soaked in a 1 in 2,000 alcoholic solution of biniodide of mercury. The cavity is then dried and a small drain of sterilized gauze inserted within the auditory ca.n.a.l, the ear being afterwards covered with a pad of gauze kept in position by a bandage.

=After-treatment.= In cases of non-suppuration there is rarely any pain, and if asepsis has been maintained, there is seldom much discharge beyond slight sanious oozing. Unless there is considerable discomfort the dressing need not be changed for two or three days. If possible the ear should not be syringed, but merely mopped out with pledgets of cotton-wool moistened with boric lotion and then dried, the gauze drain being afterwards inserted. This process may be repeated daily until healing is complete.

In middle-ear suppuration there may be considerable pain, owing to the forcible bruising of the tissues of the inner part of the auditory ca.n.a.l during the act of removal of the outer wall of the attic. Sometimes, indeed, there is much swelling of the lining membrane of the ca.n.a.l, with the occurrence of furuncles as the result of septic infection.

If there be no pain, the after-treatment is the same as above described, excepting that it may be necessary to syringe out the ear at each dressing owing to the discharge. If there be much pain, with swelling of the ca.n.a.l, the gauze drain should be removed and a 10% solution of carbolic acid in glycerine frequently instilled into the meatus.

Subsequently drops of rectified spirit may be subst.i.tuted.

=Difficulties.= 1. If the auditory ca.n.a.l be very small there may not be sufficient room to insert the instruments through the speculum. In such cases, if there be no middle-ear suppuration, it is wiser to leave the condition alone. If, however, suppuration exists, either the conservative treatment must be continued or the complete mastoid operation recommended.

2. Haemorrhage, especially on curetting away the granulations, may be sufficient to prevent a view of the deeper parts. It can, however, usually be arrested quickly by plugging the auditory ca.n.a.l with gauze soaked in adrenalin and cocaine solution. Even if the surgeon has to wait a few moments, this must be done, as it is very necessary to obtain a clear view of the field of operation.

3. Extensive adhesions between the membrane and inner wall may render it difficult to separate the shaft of the malleus without fracturing its neck.

4. In old-standing cases in which there is a large perforation of the membrane, the malleus may be so retracted as not only to be difficult to see but difficult to seize. In this particular case, division of the tensor tympani with Schwartze's tenotome and then extraction of the malleus by means of s.e.xton's forceps is a better procedure than trying to encircle its shaft with Delstanche's ring-knife.

5. Removal of the incus by the ordinary instruments may be rendered impossible owing to the narrowness of the attic posteriorly from chronic thickening of its walls. In these cases a seeker, such as Schwartze uses in the mastoid operation (Fig. 219), may be employed with advantage. It is pa.s.sed over the incus in the same manner as an incus hook.

=Accidents.= 1. _Fracture of the handle of the malleus._ This is the result of too forcible extraction. If a Delstanche's ring-knife has been used, this may be due to the tensor tympani not having been cut through; this should now be done. The head of the malleus is then removed either by means of a small hook or some form of curette bent at right angles to its shaft, depending on what is most suitable for the case in question.

2. _Failure to extract the incus._ In the course of a chronic middle-ear suppuration, the incus may become exfoliated or gradually disappear as the result of caries. It does not therefore always follow that inability to extract the incus means that the surgeon has failed in his manipulations, although frequently this is the case, the instruments failing to extract the incus, or perhaps dislodging it into the mastoid antrum, a fact which is difficult to determine and may only be discovered if the subsequent performance of the complete mastoid operation becomes necessary.

3. _Facial paralysis._ This accident is usually due to the incus hook not being inserted high enough up, so that, instead of entering the attic, it presses on the inner upper border of the tympanic cavity, and on being rotated in a backward and downward direction, it follows the line of the facial ca.n.a.l (Fig. 208). If much force be employed the frail wall of the facial ca.n.a.l will be fractured or pressed in on the underlying facial nerve. It is very rarely, however, that the nerve is completely crushed or torn through, and therefore recovery almost invariably takes place.

The facial nerve may also be injured whilst curetting away granulations in the upper posterior part of the tympanic cavity.

[Ill.u.s.tration: FIG. 208. DIAGRAMMATIC SECTION TO SHOW CORRECT AND WRONG POSITIONS OF INCUS HOOK. A, Facial nerve ca.n.a.l; A', Facial nerve, in section; B, Antrum; C, External semicircular ca.n.a.l; D, Incus hook in its correct position in the attic, _above_ facial ca.n.a.l; E, Incus hook in wrong position, about to press on facial ca.n.a.l; F, Promontory.]

4. _Injury to or removal of the stapes._ This very rarely occurs during the act of removal of the incus, but is generally the result of too violent curetting. If only the crura be broken off, it does not matter; but if the stapes itself be dislodged from the fenestra ovalis, the subsequent symptoms may be attacks of vertigo, nausea, and vomiting. As a rule these symptoms subside. If, however, the internal ear becomes infected (although judging from literature and my own experience this is of very rare occurrence), complete deafness or even meningitis may occur as the result of labyrinthine inflammation or suppuration.

=Results.= (_a_) _With regard to arrest of the disease._ If the disease be limited to the ossicles themselves and to the anterior and outer part of the attic, a favourable prognosis may be given. Complete cessation of the discharge and scarring over of the affected part may take place within a month, or after a much longer period.

If, however, the disease be more extensive and involves the walls of the attic posteriorly and the region of the aditus, as shown by the presence of a fistula or granulations, the prognosis is uncertain and continuance of the discharge and recurrence of the granulations may eventually necessitate the complete mastoid operation.

(_b_) _With regard to hearing._ In the case of chronic attic suppuration the hearing power may be increased to a distance of 12 feet off for conversation, provided the internal ear is not affected and the stapes is not fixed within the fenestra ovalis; occasionally the result is much better. On the other hand, the hearing power may be made worse.

In post-suppurative conditions, the prognosis is not so favourable, as frequently the stapes is already bound down by adhesions; this is the more probable in the case of chronic middle-ear catarrh. In both these conditions the operation should never be performed without first explaining to the patient that it is practically experimental. The chief cause of failure is the recurrence of adhesions, which even the most complete and careful operation cannot always prevent.

=Removal of the stapes.= This operation is still in its infancy and it is, as yet, impossible to express an opinion with regard to its success or failure, and therefore the indications laid down are only tentative.

The objects of the operation are: (1) to improve the hearing in cases of deafness presumably due to fixation of the stapes within the fenestra ovalis, and (2) to relieve symptoms of tinnitus and vertigo due to the same cause.

Before this operation is advised careful examination must be made in order to determine whether the labyrinth is intact, especially if the operation is undertaken with the view of improving the hearing.

=Indications.= (i) If there be ankylosis of the stapes on both sides, accompanied by marked deafness and distressing subjective symptoms, operation is justifiable on the worse side.

(ii) In a one-sided affection provided the subjective symptoms of noises and giddiness are so oppressive as to render the patient's life unbearable. The operation, of course, must not be attempted unless every other form of treatment has failed.

=Operation.= The operation may be performed either through the meatus, or by reflecting forward the auricle by means of the post-aural incision, and chiselling away the upper posterior part of the bony meatus in the manner suggested by Stacke (see p. 397).

The choice of the operation depends princ.i.p.ally on the existing anatomical and pathological conditions.

If the meatus be very narrow the intrameatal method may fail to bring the stapes into view. If, on the other hand, the meatus be wide and there be a large perforation, the result of previous middle-ear suppuration, the incudo-stapedial joint or the head of the stapes itself may be actually within the field of operation.

_The intrameatal method._ The patient should be fully anaesthetized and the operation performed under good illumination. A portion of the tympanic membrane in its upper posterior quadrant is excised in order to bring into view the incudo-stapedial joint. The incision is begun just behind the handle of the malleus and is carried upwards and backwards in a circular fas.h.i.+on through the tympanic membrane along the posterior fold, and then downwards for a little distance along its margin. The flap so made either falls downwards, or can be pressed downwards so as to expose to view the inner wall of the tympanic cavity. With a small knife, curved on the flat, the incudo-stapedial joint is cut through.

With a fine hook the long leg of the incus is dislocated forwards or backwards from the stapes. The head of the stapes will now be seen, with the tendon of the stapedius muscle running horizontally backwards. With a paracentesis knife, the tendon is cut through close to its attachment to the stapes.

A fine, blunt-pointed hook is now inserted between the crura of the stapes. If the stapes be not firmly ankylosed it can usually be removed by slight traction. If, however, it be firmly fixed, its crura will probably be broken. To determine whether the stapes is ankylosed or not, direct pressure of the probe on the head of the stapes may be necessary.

If the head of the stapes cannot be seen, it is advisable, as suggested by Dench of America, to punch out part of the upper posterior margin of the attic-wall with the attic forceps (see p. 357).

_The post-aural method._ The preliminary steps of the operation are the same as have been already described for removal of an exostosis (see p.

318).

After separating and reflecting forward the membranous from the bony portion, the upper posterior part of the tympanic ring is chiselled away until a view of the stapes can be obtained. The incus is then disarticulated from the stapes.

If the stapes be ankylosed by fibrous adhesions to the margins of the fenestra ovalis, an attempt may be made to free it by cutting through the adhesions with a fine bistoury. If this be impossible, a sharp hook may be fixed into the margin of the plate of the stapes in the hope of forcibly extracting it. Some authorities advise chiselling away of the margins of the fenestra ovalis. If an opening can be made into the vestibule by this means, it is hoped that the resulting scar tissue will form a membrane more resilient than the ankylosed stapes, and, in this way, permit vibrations of sound to enter the labyrinth. This operation, however, necessitates the complete mastoid operation in order to freely expose the region of the fenestra ovalis.

=After-treatment.= It is sufficient to protect the ear with a small gauze drain. Occasionally there may be considerable vomiting and vertigo as an immediate result of the operation; this usually pa.s.ses off within two or three days. Meanwhile the patient should be kept in a rec.u.mbent position and, if necessary, given small subcutaneous injections of morphine.

=Difficulties.= The chief difficulty is to obtain a good view; even if this be obtained it is difficult to extract the stapes without fracture of its crura.

=Dangers.= As a result of opening up the labyrinth, one would expect considerable risk of infecting the internal ear. Judging from recorded cases, this, however, seldom occurs.

=Results.= The chief advocate of the removal of the stapes is Jack of Boston (_Boston Med. and Surg. Journ._, January, 1895), who again in 1902 (_Archives of Otology_, vol. x.x.xi, p. 407) stated: (1) that removal of the stapes did not destroy the hearing but sometimes improved it; (2) that the operation upon cases of moderate deafness might give brilliant results but was also attended with some risk to the hearing; (3) that the operation on the profoundly deaf was not advisable, as usually the stapes could not be removed owing to surrounding adhesions, and even if it were, no improvement was likely to occur owing to the sound-perceiving apparatus having probably already undergone irremediable changes.

Blake (_Archives of Otology_, vol. xxii), on the other hand, states emphatically that stapedectomy is harmful rather than beneficial.

The question, therefore, of removal of the stapes from the point of view of hearing is purely experimental. If there be bony ankylosis, it will be found impossible to remove the bone, and an attempt to do so will result in fracture of its crura. If, on the other hand, it be not ankylosed but movable, probably ma.s.sage or, in cases of perforation of the tympanic membrane, direct mobilization of the bone will give results as good as those following stapedectomy.

The most favourable results are to be expected in those cases in which the operation is performed to relieve symptoms the result of previous middle-ear suppuration. In otosclerosis no benefit is ever obtained, and therefore the operation is absolutely contra-indicated.

On the other hand, there is ample evidence that the hearing power, in spite of removal of the stapes, may be retained. As an example may be quoted a case in which the stapes was removed accidentally in curetting out the ear after the removal of the malleus and incus, and in which I afterwards performed the complete mastoid operation owing to the continuance of the middle-ear suppuration. In spite of this, whispering could be heard at a distance of 20 feet (_Journal of Laryngology, &c._, vol. xxii, p. 33).

CHAPTER IV

OPERATIONS UPON THE EUSTACHIAN TUBE