Tumors within the brain will push up sulci from below, so that vessels can be tied more easily than in the normal brain. A growth should be encircled by ligatures under these circumstances. The material used in ligating varies. Tiffany used very fine sterile silk. Finally, there is that form of hmmor rhage which may come from the exposed surface of a growth, and is usually de nominated parenchymatous. Pressure with gauze will effectually arrest this. It may be that the gauze can be taken away at the end of the operation; usually it is to be left protruding and removed in two or three days.
In regard to the Special indications for one or the other anes thetic lacking, chloroform may be em ployed, as intracranial congestion is probably lessened thereby. Under ether the face becomes congested; a similar condition may obtain within the skull.
Tiffany has a cast of the brain at hand to refer to, while operating, for compari son with the exposed area. Electrical stimulation of the exposed area, by methods now well known, aid the oper ator.
When operating for a tumor of the brain which is covered by the cortex, the color and consistency of the exposed area may give information, but an in cision will probably be of advantage. Certain growths have the same consist ency as the brain, and have been trav ersed by needles without recognition; hence color and consistency failing to be recognized, probably an incision into the brain is best; touch followed by incision, if the tumor does not present, is far bet ter than touch followed by punctitre, unless a cyst is discovered.
In many cases of tumor, the cortex is greatly displaced, but it is also probable that where the cortex is removed restora tion of function, to a certain extent at all events, will follow. Circumscribed growths may be taken away by spoon, finger, knife, etc., but infiltrated growths, while they may be taken away, so far as can be recognized by the oper ator, give most unsatisfactory ultimate results, recurrence being the rule. The (Tura, being removed, should be replaced by gold foil, as advised by Beech, of Boston; or by rubber tissue, as prac ticed by Abbe; or by a thin sheet of celluloid, as employed by 11IcCoch; or egg-membrane (Freeman) to prevent ad hesions between the brain and scalp.
The following advantages are claimed for the use of egg-membrane in cerebral surgery: 1. That it is inexpensive and can be easily obtained where such sub stances as gold foil are not at hand. 2.
It is not in the full sense of the term a "foreign body," but seems, in a measure, to incorporate itself with surrounding tissues without causing perceptible irri tation or the formation of noticeable cicatricial deposits. Even though it ulti mately becomes absorbed, it remains intact sufficiently long to accomplish the purpose for which it was inserted. 3. There is no danger of subsequent infec tion requiring a second operation and leading to extensive formation of con nective tissue. Leonard Freeman (An nals of Surg., Oct., 'OS).
Intracranial sutures may be of silk or fine catgut. To obtain a bone-flap where it is thought necessary, when the natural bone is lacking, different expedi ents have been made use of: the peri osteum from the tibia has been trans ferred to the head; the outer table of skull, while connected with the skin, has been fashioned as a flap to turn over and cover the defect; the removed bone, perforated with holes so as to permit of drainage, has been used; bone-chips obtained by the use of the chisel or gouge on the adjacent sound bone have been placed on the Jura, as a mosaic with the outer side downward. These are known as autoplasty. When a piece of foreign material, as silver, celluloid.
decalcified ox-bone, calcined ox-bone. or aluminium is used, it is called heterop lasty.
of experiments on the skulls of animals to determine what happens to the disk of bone tran,pla Med in the hole made by the trephine.
It was found that the implanted hones undergo necrosis in the central parts, but that there is a more or less extensive zone at the periphery which preserves its vitality, and becomes incorporated with the newly-formed bone. The extent of this peripheral area is closely related to the youth of the subject and the slender ness of the cranium—the younger the subject and the thinner the skull, the greater the peripheral area of retained vitality in the implanted bone. The rapidity with which the dead parts of the bone become absorbed and the new bone formed is closely related to the youth of the subject and to the sponginess of the bone. Experiments with decalcified and with calcined bone clearly showed the greater advantage of the latter in the formation of strong bony tissne. Valan (Archivio per he Sci. Med., vol. xxii, No. 19, '99).