—The symptoms of mastoiditis are pain, referred to the mastoid, as well as to the region around it, although when pressure is not made by retained pus pain may not be intense; local tenderness is present in nearly all cases, and will depend upon the proximity of the trouble to the surface. This tenderness is evoked by gentle pressure, which will sometimes produce pitting, or by tapping lightly with the finger. When the trouble is superficial there will often be edema, with all the local evidences of suppuration. In addition to this there will be coincident symptoms of disease of the middle ear, with discharge, earache, etc., and frequently edema or actual phlegmon of the auditory canal.
The different directions in which destructive processes may extend, and their consequences, are as follows: (a) Externally, with well-marked local evidences of the proximity of pus; (b) anteriorly into the meatus, with phlegmonous appearances in that canal; (c) upward, through the roof of the tympanum or the antrum, with disastrous cerebral symptoms or extradural abscess; (d) inward, toward the sinus, with consequent thrombophlebitis, extradural abscess, and perhaps cerebellar abscess; (e) downward, and away from the mastoid, with phlegmon deep in the neck.
The first appearance of symptoms of any of these complications should awaken apprehension and demand scrupulous attention. Any collection of pus along the auditory canal should be promptly incised, and the first indication of mastoid tenderness or inflammation should cause a prompt application of leeches, followed by antiseptic irrigations. In this way it may be possible to avert serious symptoms, provided these measures be instituted early.
But with either the access of local symptoms indicating the presence of pus, or of more general symptoms, elevation of temperature, acceleration of pulse, headache, or anything else suggestive of dural irritation or cerebral complication, no time should be lost in making free and radical operation. The mastoid operation, so called, is then demanded in these cases. When thus indicated the first objective point should be the antrum. In order to reach this the customary incision of many writers, back of and parallel to the posterior convex border of the ear, is insufficient and uncertain. The antrum lies within what Macewen has described as the suprameatal triangle, and is to be regarded as the key to the situation. It is necessary to recognize the posterior zygomatic root, which projects behind and above the ear, as well as the tip of the mastoid process, and then to make a perpendicular linear incision, about a quarter of an inch behind the posterior border of the external osseous meatus, extending from this posterior root down to or nearly to the mastoid tip. The surgeon should cut down directly upon the bone, without dissecting or scratching his way through the different tissue layers. The posterior auricular attachments are thus fully exposed, and should be reflected forward, so that the posterior aspect of the external meatus is fully exposed. After thus exposing the bone the surgeon notes the position of the superior meatal triangle, which is formed by the posterior zygomatic root, the upper posterior segment of the external osseous meatus, and an imaginary line uniting these two, extending from the most posterior portion of the osseous meatus to the zygomatic root. Within this triangle the mastoid antrum may be entered, its depth being proportionate to the depth of the middle ear from the surface. So long as care is exercised the sigmoid groove will not be injured. The depth at which it lies from the surface varies. It is more superficial in children, while in adults with chronic ostitis of the region it may have a thick covering. When opened it should be thoroughly cleansed, for it may contain not only pus but granulation tissue or masses of cholesterin. After cleansing the antrum the passage between it and the middle ear should be noted, as well as the position of the facial canal, which traverses its inner side obliquely from without inward as it passes into the inner wall and roof of the tympanum. It is recognizable by a ridge of harder osseous tissue. If changes have occurred in the surrounding bone it may not be recognized. If the operator keeps to the upper and outer part of the antrum he will avoid the nerve. Any injury to it will produce facial twitching. The bony canal may be eroded by granulations, so that the nerve itself may be exposed when the antrum is being cleansed.
The mastoid cells lie posteriorly and below this antrum, and should be exposed, when cleaning out their morbid contents, by removing the external mastoid wall. In this part of the operation the sigmoid groove should not be forgotten, as it may have been disintegrated by granulations which have extended into the fossa and separated the dura from the bone. When granulations have thus formed there is usually more or less thrombosis of the sigmoid sinus in addition to the localized pachymeningitis.
The instruments which may be employed during this work are a matter of choice. It can be done with the ordinary bone instruments of the general surgeon, which should, however, include gouges and curettes of small size as well as delicate chisels and mallet. A dental or surgical engine is advisable, which will serve admirably and for the desired purpose. Just what instrument should be used and how manipulated will depend upon the more or less pneumatic (i. e., cellular) character of the bone. Some mastoids are richly cellular. Pus or granulation tissue should be followed wherever it may lead.
When both mastoid cells and tympanum participate in the morbid process, and are practically filled with pus, debris, or granulations, there may then be added to the operation those features which entitle it to be called tympanomastoid exenteration, as devised by Schwartze, Zaufal, Stacke, and others, and frequently described under their names. It is an extension of the measures already described, and results in converting the mastoid cells and antrum, the tympanic cavity, and the auditory canal into one common cavity. Not only is the bony barrier between the antrum and the tympanum removed, but the ossicles as well. This leaves a large cavity, which should be partially closed and lined by granulation and cicatricial tissue, epithelial lining being furnished so far as it may extend from the exterior.
The operation may be begun practically as already described, the incisions being more extensive and the auricle more freely detached, so as to be reflected forward. There need be no particular effort to save the periosteum over the area of the attack, although there is no objection to reflecting it with the softer tissues. Some operators prefer to detach the cartilaginous meatus and the ear from its osseous insertion and to shift them all farther forward. The antrum and the mastoid cells having been exposed, opened, and cleaned out, the surgeon next passes forward and upward to the external wall of the epitympanum, and the dividing barrier of bone between the tympanum and the mastoid. This cavity being uncovered, the incus, if present, may be lifted out of its position, or all of the ossicles removed in as gentle a manner as circumstances will permit. All the bony prominences and partitions between the tip of the mastoid and the anterior wall of the tympanum are then smoothed off with a curette, or surgical engine, while granulation tissue is followed in to any recesses which may be occupied by it, or along any of the cranial outlets which it may be seen to traverse. One gives the greatest care to avoidance of injury to the horizontal semicircular canal, to the aqueduct of Fallopius, or to inadvertent puncture of the sigmoid groove. The Fallopian aqueduct, or canal, lies in the ridge between the mastoid and the meatus, along the floor of the aditus, and it should be spared in the process of cutting away the bone.
If the membranous portion of the meatus has been split, as advised by some operators, its margins may be brought together with chromic gut. At all events the auricle should be brought back into place after the cleansing is finished, where it should be fastened and retained by sutures as well as by the dressings. Should there be insufficient skin to cover the opening thus made, slide a flap, or even cover the exposed raw area with a skin graft. The former will usually be the better plan. The cavity left after such closure should be packed with gauze, on which balsam of Peru should be used. This may be left for two or three days, after which a daily dressing, with irrigation or suitable cleansing, will suffice.
Most of the mechanism of the middle ear is apparently destroyed, but loss of hearing is not complete.