In adults necrosis is rare excepting as a localized patch usually situated superficially in the cortex of the mastoid process. Partial necrosis of the labyrinth, more especially of the vestibule and the portions of the semicircular canals, is also met with occasionally. When the necrosed area is superficial, such as the squamous portion of the temporal bone or the cortex of the mastoid process, it should be removed. If, however, it be situated more deeply, forcible removal should not be attempted until the sequestrum becomes loose, the wound cavity being meanwhile kept as aseptic as possible.
Osteomyelitis. In children, as the result of acute inflammation of the mastoid process, the bone may be found riddled with small points of pus, sometimes termed osteomyelitis. As a result of free opening of the mastoid cavity recovery, as a rule, takes place in the ordinary manner.
Distinct from this is another condition in which thrombosis of the diploic veins occurs. It is, fortunately, a rare complication of mastoid disease. It may occur before operation or be the result of infection of the bone as a result of operation. The infection tends to spread in every direction, more especially upwards along the parietal region and towards the occiput. With this, localized areas of necrosis or abscesses may occur, giving rise to painful swellings on the head, and usually are accompanied by cellulitis of the scalp, pyrexia, and intense headaches.
The only chance of recovery is to expose the affected area freely, and thoroughly remove all the diseased bone. To do this it may be necessary to lay bare the dura mater over a considerable area. If, however, the disease be not quickly eradicated, death will eventually occur as a result of extension of the septic infection to the larger veins, or from some other intracranial complication.
CHAPTER VI
THE COMPLETE MASTOID OPERATION
Before considering the question of the radical operation, it is assumed that conservative treatment has been attempted and has failed, and that the middle-ear suppuration has existed for a considerable period.
Indications. (i) As a prophylactic measure. If there be merely a perforation of the tympanic membrane and no evidence of disease of the ossicles nor the walls of the tympanic cavity, the probability is that the continuance of the suppuration is due to an affection of the mucous membrane rather than of the underlying bone; for example, to a chronic empyema of a large antrum cavity which, owing to its anatomical structure, will not drain freely.
In such cases the complete mastoid operation is only indicated if the deafness is extreme, the bone conduction diminished, and the high tuning-forks not well heard, or if the ossicles are bound down by adhesions to the inner wall of the tympanic cavity, as it is then obvious that the hearing power cannot be restored completely.
It must, however, be remembered that in many cases a slight discharge may exist for years without giving rise to any complications. If the patient be made aware of the slight danger which exists in every case of middle-ear suppuration, and be in a position to obtain medical attention if retention of pus occurs, then operative measures may be deferred indefinitely. If, on the other hand, the patient intends going to some remote country where medical attendance is impossible, then it is probably wiser to submit to the complete operation rather than risk future trouble.