CHAP. XVII. Why we use Trepaning, in the Fractures of the Skull.
THere are four causes of this remedy: The first is, to raise up the deprest Bones, and take forth their fragments, which press upon the Meninges, or also upon the substance of the Brain. The second is, that the Sanies or matter may be evacuated, clensed, wasted, and dry∣ed up, which by the breaking of any vessel is poured forth upon the Membrans, whereby they, and not they only, but the Brain also is in a great danger of corruption. The third is, for the fitter application of medicines, convenient for the wound and fracture. The fourth is, that so we may have something whereby we may supply the defect of a Repelling Ligature, and such an one as may hinder defluxions;* 1.1 for such a Ligature cannot take place here as it may in the other parts of the body, by reason of the Sphaerical or Round figure of the head, which doth not easily admit binding; and then the density and hardness of the interposed Skull is a means that the vessels lying under it, (by which usually the defluxion comes) cannot easily be bound with a rowler sufficiently to repel the running bloud. And the external vessels, (to whom the force of the Ligature may come) can∣not be bound without great pain, and danger of inflammation. For by such a compression the pul∣sation of the Arteries would be intercepted, and the efflux of the fuliginous excrements which useth to pass pass through the sutures of the Skull, would be supprest, by reason of the constriction of these sutures.
* 1.2Besides also, the bloud would thus be forced from the wounded part without, to within into the Membranes and Brain; when pain, inflammation, a Feaver, Abscess, Convulsion, Palsie, A∣poplexie, and lastly, Death it self would insue.
And these are the cheif causes, that Trepaning is necessary in fractures of the skull, and not so in the fractures of other Bones.
But before you apply or put to your Trepan, the Patient must be fitly placed or seated, and a double cloth must be many times wrapped about his head, and then his head must be so laid, or pressed upon a Cushion or Pillow, that when you come to your operation, it may not sink down any further, but remain firm and stedy. Then you must stop the Patients Ears with Cotten-wool, that so he may not hear the noise made by the Trepan, or any other Instrument.
* 1.3But before you put to your Trepan, the Bone must be pierced with an Instrument, having a three-square point, that so it may be the more speedily and certainly perforated. The point there∣of must be no bigger then the pin of a Trepan, that so the Trepan which is forthwith to be applyed may stand the more firm, and not to play to and again in too wide a hole.
The shape of this Instrument is not much different from a Gimblet, but that the point is three-square, and not twined like a screw, as you may perceive by this following figure.