A System of Operative Surgery Part 50

In this operation the bony outer wall of the orbit is divided above and below, and turned outwards so as to expose the orbital contents without interfering with the globe; the bony wall, being kept attached to the overlying tissue, can be replaced subsequently without fear of necrosis.

=Indications.= The operation is performed in cases of a suspected tumour of the orbit, which, if small and non-malignant, can be removed, the eye being left _in situ_. If doubt exists as to the nature of the tumour a piece can be removed and examined microscopically, either at the time of the operation or later. It is especially suitable for tumours of the optic nerve and for orbital cysts behind the globe.

=Instruments.= Scalpel, dissecting forceps, artery forceps, scissors, periosteum detacher, chisel and hammer, or preferably, a motor rotary saw, and retractors.

=Operation.= Performed under a general anaesthetic.

_First step._ A slightly curved incision with the convexity forwards is made so as to expose the outer margin of the orbit and carried down to the bone. The periosteum is separated from the inner surface of the outer wall of the orbit by means of a periosteum detacher and divided horizontally, the finger is inserted, and the orbit explored. If a small tumour or cyst be found it can sometimes be sh.e.l.led out through this incision without enlarging the wound further.

_Second step._ The eye and orbital contents are carefully protected with a large flat retractor. The bone is first divided above, by means of either a chisel or a saw. The upper incision should pa.s.s through the base of the external angular process of the frontal bone, and run backwards and slightly downwards to the posterior end of the spheno-maxillary fissure. The lower incision should run directly backwards from the lower orbital margin into the spheno-maxillary fissure. The triangular wedge of bone attached by its outer surface to the soft tissues in the temporal fossa is then forced outwards. In doing this care must be taken not to fracture the orbital wall anteriorly, otherwise the s.p.a.ce to work in will be much reduced.

_Third step._ Consists in the removal of the tumour. Care must be taken to displace the external rectus to one side so as to avoid injury to it as much as possible. If the case should be one of an optic nerve tumour, for which the operation is most frequently performed, the optic nerve is divided close behind the globe. The tumour is freed from the surrounding ciliary nerves and the ophthalmic artery and brought up into the wound as much as possible. The optic nerve is then divided at the apex of the orbit and the tumour removed. The wound in the periosteum of the outer wall of the orbit is closed with a catgut suture, the bone, together with the soft parts, replaced in position and the skin wound closed by sutures. A drainage tube should be inserted for at least twenty-four hours.

=Complications.= 1. _Proptosis._ The operation is liable to be followed by great proptosis as the result of haemorrhage into the orbit. If the optic nerve has been removed, the globe may be dislocated forwards between the lids and come in contact with the dressings.

2. _Corneal ulceration._ As the cornea is frequently anaesthetic from division of the ciliary nerves, ulceration is very liable to follow. It is, therefore, desirable in many cases to st.i.tch the lids together after closing the skin wound.

3. _Defective outward movement in the globe_ is of frequent occurrence, owing either to injury of the external rectus or the sixth nerve, or to involvement of them in the scar tissue. St.i.tching the periosteum together obviates the latter to a certain extent.

4. As the wound cicatrizes a certain amount of _enophthalmos_ is very liable to result.

EVISCERATION OF THE ORBIT

=Indications.= This operation is usually performed for some form of new growth originating either in the eye or the orbit.

=Operation.= This may be modified (1) according to the _position_ of the growth. In severe cases of rodent ulcer and sarcomatous growths, which involve the lids, it is desirable that the lids should be removed with the tumour; but in cases of tumour of the optic nerve, or disease situated far back in the orbit, and not involving the lids or conjunctiva, these structures may be retained, since a much better socket is thus obtained. (2) The _nature_ of the growth. In simple tumours, such as naevi and some cases of arterio-venous aneurism which have failed to yield to other treatment, the incomplete method, in which the lids are retained, is all that is necessary, but in malignant cases they should be removed.

_The Complete Method._ An incision down to the bone is first made, completely encircling the orbital margin and including any growth that may be involving the skin. The periosteum is then separated completely, as near to the optic foramen as possible. Care must be taken in dealing with the periosteum over the lachrymal bone, as the bone is liable to be fractured and an opening made into the nose if undue force be used. The apex of the cone formed by the periosteum is divided, as far back as possible, with curved scissors, and the whole orbital contents are removed. The wound is packed with gauze, and skin-grafting is subsequently performed when the bone has become covered with granulations; this usually occurs about the end of the second week.

_The Incomplete Method._ The globe is first enucleated and the outer canthus divided. The lids are well retracted and an incision is carried down to the bone along the orbital margins. The periosteum is then stripped up from the walls of the orbit and the apex of the cone divided as far back as possible, as in the previous operation. The conjunctiva and outer canthus are then united with sutures. As a rule, skin-grafting is not necessary after this operation.

OPENING AN ORBITAL ABSCESS

Orbital abscesses should be incised where they point. In the upper lid care should be taken not to divide the levator palpebrae muscle; the incision should be placed well to one side. In making an incision over the inner side of the orbit care should be taken not to detach the pulley of the superior oblique. The cause of the abscess should be ascertained if possible. Suppuration in the ethmoidal sinuses coming through from the nose is the commonest cause, and should be treated appropriately (see Section V).

SECTION III

OPERATIONS UPON THE EAR

BY HUNTER F. TOD, M.A., M.D. (Cantab.), F.R.C.S. (Eng.) Aural Surgeon to the London Hospital

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 ca.n.a.l 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.

[Ill.u.s.tration: FIG. 171. CLAR'S LAMP.]

=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 ca.n.a.l, 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).

[Ill.u.s.tration: FIG. 172. GRUBER'S AURAL SPECULUM.]

[Ill.u.s.tration: FIG. 173. ANGULAR SPRING FORCEPS.]

=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 a.s.sistant 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 ca.n.a.l, 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 ca.n.a.l and tympanic cavity under local anaesthesia.

[Ill.u.s.tration: FIG. 174. EXAMINATION OF THE EAR.]

[Ill.u.s.tration: FIG. 175. AURAL FORCEPS HOLDING COTTON-WOOL.]

=Method of cleansing the ear.= Except when the auditory ca.n.a.l is completely blocked by insp.i.s.sated pus, cerumen, or epithelial debris, 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 fas.h.i.+on that it partially projects beyond its points (Fig. 175). The forceps is pa.s.sed through the lumen of the speculum along the auditory ca.n.a.l 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 ca.n.a.l to the drum, and returns along the floor, thus was.h.i.+ng out the contents. The best syringe is one with a metal plunger, as it can be easily sterilized. After syringing, the auditory ca.n.a.l should be dried and again inspected. If the insp.i.s.sated pus or epithelial debris 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.

[Ill.u.s.tration: FIG. 176. MILLIGAN'S INTRATYMPANIC SYRINGE.]

=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 pa.s.sed inwards along the auditory ca.n.a.l, 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 ca.n.a.l 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.