TEARING AND TORSION.
These two modes of operation may, to a great extent, be considered as identical. Indeed, the mode of torsion may be said to have arisen principally as a modification of that of tearing, which is the older. In tearing, the cord was subjected to a certain amount of torsion by the hand, and then torn apart at a given point in its length; while in the process of simple torsion, as properly performed, we obtain a division of the cord by twisting it with instruments, which enables the operator to effect the separation at a definitely determined spot. Tearing differs, then, from torsion only in the fact that after giving several twists to the cord in order to gather its fibres into a more compact mass, and to diminish the resistance of the more superficial layers, it is divided in its continuity by a violent traction upon its fibres in the direction of its length.
In this process, especially applied to ruminants, the testicle being exposed, the operator secures the cord firmly with the thumb and index finger of one hand, to prevent the traction from taking effect too far upwards when being made by the other hand, after the cord has been twisted a few times on itself.
TORSION.
In this method of castration the cord is twisted with sufficient force to cause it to break of itself at the point of the greatest violence. Its design is to accomplish the removal of the testicle without dragging or excessive traction upon the cord, and thus to avoid the hemorrhage following the torsion of the spermatic artery, as a mode of hemostasis sufficient to prevent the flow of blood attendant upon the rupture of the cord. The operation may be performed either above or below the epididymis, or may consist simply in the torsion of the artery alone. At first the hands only were called upon to act in the manipulations, and the operation was from this cause known as free torsion, until about fifty years ago, when instruments were introduced into general practice, and gave rise to the plan of limited torsion.
FREE TORSION.
Free torsion, or that in which the hands alone are employed in the operation, may be performed, as before stated, either above or below the epididymis.
Above the Epididymis.—The first is one of the oldest modes of castration known; one which must have been practiced contemporaneously with the use of clamps, or in the first age of surgery. The first steps of the operation required for the exposure of the testicles are the same as have already been detailed. When this is accomplished the steps of torsion and rupture are then performed in the following manner: The operator, grasping the testicle, carefully draws out the spermatic cord, and with a pointed bistoury makes a transverse incision, above the tail of the epididymis, through the posterior septum of the cord, involving what we know as the white muscle of Bouley, the efferent canal, and the small testicular artery. He then seizes the anterior fasciculus of the cord between the thumb and index finger of the left hand, squeezing it as tightly as possible, and having with the other hand secured the cord at a short distance below the point where the left hand has already been placed, performs the torsion by a rotatory movement given to the testicle itself, the motion having for its result the twisting and tearing of the cord when long enough continued to overcome the tenacity of its fibres. Fifteen or twenty turns of the organ will usually be found sufficient to effect the rupture. A considerable degree of strength in the fingers is required in this movement, and for this reason the torsion may take effect further up than may be desired, and beyond the point designed, which may result in an unnecessary amount of irritation and injury. When the torsion has gone so far that the rupture of the cord has been effected, the stump is released, and retracts in the inguinal canal to a certain height limited by the presence of the posterior septum, which holds it in place, and to a great extent prevents its return through the superior orifice of the inguinal canal.
Below the Epididymis.—This, the fourth step of the operation, consists in the separation of the testicle from the epididymis and the torsion of one upon the other. The testicle being exposed, the operator, taking hold of its appendix, the epididymis, with the left hand, and of the gland with the right, their cellular serous attachment is divided by the thumbs from the posterior to the anterior extremity, from the tail to the head of the twisted efferent canal. If this cannot be done with the hand, the convex bistoury must be called into action. This accomplished, the head of the epididymis is firmly secured with the fingers of the left hand, and the right hand, left free, gives to the testicle the number of rotatory motions necessary to separate it from its excretory canal—that is, from eight to ten. When the testicle is thus severed, the stump of the end, with the epididymis, is pushed back into the vaginal sac, where it is confined by the application of a suture upon the middle of the edge of the scrotal wound.