PSOAS ABSCESS.
This may be regarded as practically always of tuberculous origin, the disease starting in the vertebral column. The treatment of the resulting abscess has been already described in the article on Caries of the Spine and the general principles have been discussed under Abscess. For conveni ence of reference the operative procedures may he here summarised, but it must be remembered that a psoas abscess being devoid of the presence of the ordinary pyogenic organisms in a small percentage of cases it may, under proper rest, open-air and antituberculous treatment, shrivel up or wither without surgical interference. This possibility should never tempt the surgeon to wait till the skin over a pointing abscess becomes involved, as the aim in all procedures must be to prevent the sac of the abscess becoming infected from without by pus-forming microbes.
The abscess should therefore be incised through healthy skin when possible, and after the evacuation of its contents the sac must be thoroughly irrigated by a stream of hot normal saline solution, and all semi-solid caseous products mopped out by sterile gauze, and the cavity filled with a io per cent. emulsion of Iodoform in glycerin or a ro per cent. solution in ether. After permitting the excess of emulsion to escape, the lips of the incision are secured by fine sutures, and the utmost antiseptic precautions taken by the application of suitable absorbent wool dressings or iodoform gauze, no drainage being provided. It is usual in these cases for refilling of the sac to occur, not, however, with pus, but with serum. Repeated aspiration of this fluid through one angle of the wound will succeed in causing complete recovery provided general methods of treatment are applied at the same time.
In any case, Barker's method should be tried before resorting to drainage. It consists in opening the abscess by a small incision at its most dependent part, through which a flushing curette is introduced and the cavity thoroughly scraped out, the debris detached from the walls of the sac being washed away by the continuous stream of warm saline passing through the curette; the walls of the abscess track are further mopped by long strips of gauze and the wound sealed up without a drain. It may sometimes be
possible by a free incision to remove loose carious bone, after which the sac may be filled from the bottom by packing it tightly with gauze to stop all hmmorrhage; when this has been accomplished, after waiting for some minutes, the gauze is gently withdrawn, and the walls covered with dry powdered Iodoform before sealing up the wound, or the cavity having been packed with Iodoform gauze, this is left in situ to encourage healing by granulation.
Some surgeons advocate and carry out a more radical operation by freely exposing the diseased vertebr and removing the lamina and spinous processes.
When secondary infection has already occurred there is no resource but to fall back on drainage, and the surgeon will sometimes be compelled to drain when the cavity continues to refill though no external organisms have been admitted.
A marked advance has been made by Beck's method of dealing with old sinuses and long sinuous tracks, which consists in injecting a paste of Bismuth liquefied by heat (Bismuth Subnitrate 6, Soft Paraffin n, White Wax i, and White Vaselin 12). This of the consistence of cream should be forcibly injected into the sac so as to fill up all sinuses and pouches con nected with them, and the injections should be continued every second day till healing is accomplished. It must he noticed that this paste is un suitable for injection into the abscess cavity in the absence of sinuses, when the wound is to be sealed up, as after the use of iodoforin emulsion.
The after-treatment of psoas abscess must be conducted upon the generally recognised principles of dealing with every other form of localised tuberculous lesion. In some cases Vaccine treatment has been proved serviceable. When urgent symptoms clue to psoas abscess have disap peared it may be advisable to prevent spinal deformity by the introduction of an Albee's Bone Graft. This acts as an internal splint; and when the patient begins to go about, prevents the undoubted tendency to recurrence of signs and symptoms of the caries and abscess.