Before these methods be contrasted with each other, a few additional remarks seem re quired in reference to the operation however performed.
1. The posture of the patient should be such as will most relax the abdominal muscles in order to prevent as much as possible their pressure upon the viscera, and to allow the more easy separation of the edges of the wound. The shoulders should be raised and the legs bent upon the pelvis.
2. It seems desirable that unless the super ficial wound be longer than has been stated, the division of the aponeurosis of the external oblique should be of equal extent.
3. The recommendation to divide that apo neurosis upon a director appears judicious as a means both of facility and safety.
4. Where it can be used the finger seems a safer instrument with which to separate the internal oblique and transversalis muscles from the structures beneath, for it will be readily understood that the extremity of a director might be easily thrust through the peritoneum in the execution of this step.
5. It must be borne in mind that between the muscles and the artery there are to be pected beside the peritoneum two other tures : 1. the fascia transversalis ; 2. the mediate investment of the vessels. The fascia transvcrsalis may either be treated in the mariner directed by Cooper, viz. by dilating the deep ring, or be lacerated with the nail, as mended by Guthrie, but it is to be recollected that a prolongation of the fascia descends upon the spermatic cord, and that therefore there exists no opening, and that the fascia varies in strength, and may at times be found so strong as to require more force to lacerate it than it may he deemed proper to exert. In such case an opening may be made through it with the knife, and enlarged upon a director if necessary. This may be effected by either of two methods, viz. either by dividing the prolongation of the fascia, which descends upon the spermatic process, " having been first raised with a forceps, to a sufficient extent to admit the forefinger to pass upon the cord into the internal abdominal ring,"—a proceeding adopted by Mott, and which offers a safe mode of opening that structure ; or by cutting the fascia upon the outside of the ring, in the di rection toward the superior spine of the ilium, to such an extent as may allow the introduction of the director or the finger : the section can not be attempted safely inward, because of the vicinity of the epigastric artery, which is so near to the inner side of the deep ring that it must in such case be exposed to imminent danger, situate as it is between the fascia and the peritoneum ; on the other hand the more close attachment of the fascia to the latter membrane in proportion as it recedes from the crural arch forbids the section of the fascia di rectly upward ; while the existence of the tri angular interval, which has been described, between the fascia and the peritoneum imme diately above the arch renders the membrane safe from injury in a division outward near to the arch : it must however be recollected that in approaching the arch the circumflex ilii artery is also approached and endangered, so that the incision should not be brought too near to that part, but made in the direction mentioned, nor in any case be larger than will suffice for the introduction of the finger or the director.
G. The immediate investment of the vessels frequently opposes great resistance to the sepa ration of the artery and vein, and to the iso lation of the furrner; this impediment is due not merely to the strength of the investment, but also to the absence of a resisting support behind the vessel as it recedes from the pubis, in consequence of which it yields to the pres sure exerted to separate it. In such case the nail, the director, or the knife has been recom mended for the division of the expansion; Abernethy made a slight incision on either side of the artery. The nail does not seem the best instrument in this instance, because, by the use of it the vessel must be a good deal dis turbed, a circumstance to be avoided when ever it can be ; the knife again must be attended with risk unless used with great caution and in steady hands, and the risk is the greater when the incision is made at one side of the artery, since the vein is thereby endangered ; it would seem a safer proceeding and one less likely to disturb the artery unnecessarily, if, wben it can be done, the investment were pinched up with a forceps over the middle of the artery and then divided to the extent to which it may have been raised, after which, with the director or the blunt ancurism-needle, the artery may be isolated with facility while the investment. is drawn to either side with the forceps.