OPERATIONS FOR EXTRA-DURAL ABSCESS
This is far more common as a sequel of acute than of chronic disease of the mastoid process.
Indications. Operative interference is indicated in order to permit of drainage. An extra-dural abscess is frequently discovered accidentally, especially if the surgeon follows out the golden rule to trace any patch of carious bone to its limit. In doing so he may suddenly meet with a gush of purulent discharge coming through an opening in the bone in the region of the tegmen tympani or sigmoid sulcus.
Although an extra-dural abscess may give rise to no special symptoms, the following are suggestive:—
1. If, in spite of opening up the mastoid cells and antrum, pyrexia and headache persist, especially if the headache be localized to the affected side and accompanied by tenderness on pressure above the ear or behind the mastoid process.
2. If, before operation, there be a very profuse discharge from the ear, apparently too copious to come from the tympanic cavity or mastoid antrum.
3. In children an extra-dural abscess may give rise to symptoms of cerebral irritation or compression if it extends upwards from the tegmen tympani along the parietal region; or, if situated in the posterior fossa, to retraction and stiffness of the neck.
Although such symptoms may be also associated with an intracranial abscess or meningitis, yet, if on exploration of the intracranial cavity a large extra-dural abscess be discovered, further operation may be postponed (unless its extension is obviously necessary) until time is given to see whether the symptoms will subside or not.
Operation. If the mastoid process has not been opened already, the simple or the complete operation is performed, according to whether the suppuration is recent and acute, or is of long standing.
If, however, this has been done, the wound is reopened, all granulations are curetted away, and the cavity is cleansed and dried.