DESCRIPTION OP COLORED PLATE ON THE LOCATION OF APPENDICULAR ABSCESSES. A circle of an inch and a half in diameter,— the size of a silver dollar,—drawn about the centre of the posterior surface of the excum, will touch the base or point of origin of the appendix in about 9G per cent. of all eases. It will thus be seen how constant is the loca tion of the base of the appendix. The average length of the adult appendix is nine centi metres, or three and one-half inches. A circle then, of four-inch radius, drawn about the same centre as the smaller circle, will give a very large area in the abdominal cavity, any where within which the apex of the normal appendix may be found located. (See Fig. 1.) The space within the large circle (see Fig. 2) may be subdivided into five separate areas (marked 1, 2, 3, 4, and 5), each having dis tinct and well-defined boundaries. The appen dix may be found in any one of these areas, and, when an abscess forms about the in flamed organ, it is the particular area in which the appendix is located which gives the abscess or exudate its characteristic location and outline, which limits its extension in one direction and favors it in another, and which should guide us in the selection of the best point for incision.
Area 1: Infra-mesenteric.—The appendix is met with in this area in about GO per cent. of the cases, either superficially situated, approaching anteriorly, or lying deeply on the posterior wall; it may extend directly inward, hugging the under surface of the mesentery at the ileum, or inward and downward, reach ing often into the true pelvis. The mesentery above prevents the extension of abscesses in an upward direction, but gives them a tend ency to extend forward and to the left.
The pelvic abscesses are limited in the male anteriorly by the bladder, posteriorly by the rectum and pelvic wall and above by the sig moid and loops of small intestine. In the female they fill Douglas's cul-de-sac or occupy the ovarian region on one or both sides, where they are often with great difficulty differentiated from pelvic abscesses of tubal or ovarian origin. The danger of infecting
the general cavity on opening these abscesses from above is very great, and the advisability of draining through the vagina in the female, as in other septic pelvic troubles, comes into serious consideration.
The inter-intestinal abscesses (see also Figs. 3 and 4) are usually situated near the median line, and are consequently best opened at this point. Adhesions may limit them, or there may be no adhesions and the free peritoneal cavity must be traversed to reach the abscess, after packing with iodoform gauze to prevent diffusion of pus. It is often impossible to prevent pus escaping into the general cavity, with a resulting fatal acute septic peritonitis. It is in those eases that the advisability of doing a deu.r temps operation should be con sidered. Should the appendix be found float ing free in the abscess-cavity it may be re moved, but if it be firmly imbedded in the exudate forming part of the abscess-wall it should, under no circumstances, be torn out and removed, if by so doing we endanger breaking into the general cavity, thus leading to general sepsis.
The exudate may also come to the surface, forming adhesions to the anterior abdominal wall, just internal to the crecum. (See Fig. 5.) The abscess is limited externally by the CfeCUM and internally by the loop of ileum which almost always covers over the end of the ececum and the omentum. It is usually best opened by a vertical incision over the inner border of the emeum. Care should be taken not to separate the loop of intestine in ternally, particularly at its lower angle, as pus then escapes at once into the pelvis. The appendix can nearly always be removed, as it usually lies posteriorly or anteriorly, and it can be done without disturbing the internal wall of exudate which protects the general cavity.