Cases of gangrene of even large portions of bowel are by no means necessarily fatal. They may recover with an artificial anus, the remedy of which by surgical means we must notice in its proper place.
Operation for Strangulated Femoral Hernia.—While the general principles guiding treatment and ruling the conduct of the operation are the same as in inguinal, there are some differences in points of detail which render a brief separate description necessary.
A single word on the anatomy. Tracing a femoral rupture from within outwards, we find that its first stage is to push its way through the weak point of the arch formed by Poupart's ligament, that is, the spot called the crural arch, bounded on its outer side by the sheath of fascia which surrounds the femoral vein; above by Poupart's ligament; on its inner side by the curved fibres of Poupart's ligament, which, curving backwards, are inserted into the ilio-pectineal line, have a sharp falciform edge, and have been dignified by the special name of Gimbernat's ligament (Fig. xxxii. g); and below by the os pubis itself. This arch or ring thus bounded is, in the normal state of parts, filled by a layer of fibrous texture, a little fat, and occasionally a small gland. These parts are pushed forwards in the descent of the hernia, and in a small recent one may be said to form a sort of inner covering; in a larger and older one they are split by the hernia, and, while forming a constriction round its neck, leave the fundus of the sac, so far as they are concerned, quite uncovered.
A femoral hernia may stop there, satisfied with merely coming through the ring, and, if sudden and recent in a healthy, well-knit subject, such a rupture is exceedingly dangerous, the constriction being very severe, and the consequent gangrene of the bowel very rapid if unrelieved. In most cases, however, it makes its way still further out, and the next covering it gains is from the cribriform fascia. This is the layer of fibres, pierced (as its name implies) with orifices for the passage of veins and lymphatics, which stretches between the two curved edges of the saphenous opening. It varies much in strength; when the rupture has been slow and gradual, it will certainly add a covering of greater or less thickness, but where the hernia is large and old we must not expect to find many traces of the cribriform fascia, at least over the fundus of the tumour.
The ordinary superficial fascia of the part, with its fat, nerves, veins, and lymphatics, and the thin skin of the groin, are the only remaining coverings. It is very remarkable how exceedingly thin all the so-called coats become in large femoral herniæ of long standing, especially in thin old people.
Operation.—Various incisions are recommended. The one which gives freest access and exposes the sac best, is shaped like a T, the horizontal limb of which is oblique, the direction of the obliquity varying on the two sides. The horizontal incision should be made just over Poupart's ligament, and parallel to it, the centre of the incision corresponding to the neck of the sac, and its length varying according to the size of the tumour and the depth of the parts; the other should extend downwards from the centre of the former, as far as is necessary to display the whole sac. The first should be made by pinching up and transfixing the skin, the second by ordinary incision, to the same depth as the first. The small flaps thus made must now be thrown back; any vessels that have been divided are to be tied. Now, with great care and caution the surgeon is to pinch up and divide any layers of condensed cellular tissue which may still cover the sac, till it is thoroughly exposed to its full extent, and remove any glands which may intervene.
The neck of the sac being exposed, it may be possible in some very exceptional cases to give the patient the benefit of the minor operation, which consists in leaving the sac unopened. In such a case (to be described immediately), the surgeon passes his finger along the neck of the sac as far as possible into the ring, and then with a probe-pointed bistoury very cautiously nicks the upper edge of Gimbernat's ligament, in one or more places, being careful to feel for any pulsation before dividing a single fibre. He may then be able to empty the sac of its contents, and return the bowel and omentum, still retaining the sac outside.
On the other hand, where it is determined to open the sac, the pinching up of the sac must be managed with great care, to avoid injury of the bowel. There is generally a little fluid to be found at the fundus, which will protect the bowel. In one case in which Liston operated, he tells us, "there was no possibility of pinching up the sac, either with the fingers or forceps; it contained no fluid, and was impacted most firmly with bowel; very luckily the membrane was thin; and, observing a pelleton of fat underneath, I scratched very cautiously with the point of the knife in the unsupported hand, until a trifling puncture was made, sufficient to admit the blunt point of a narrow bistoury."[144] If the sac contains bowel and omentum, it is safer to open it over the omentum than over the bowel. When a small opening is made, an escape of the contained fluid takes place, and then the sac should be slit up as far as its neck by a probe-pointed bistoury, guided by the finger, introduced to protect the bowel, whenever the opening is sufficiently large. The forefinger must now be cautiously insinuated into the neck of the sac, the nail being directed to the bowel, the pulp to the crescentic margin of Gimbernat's ligament, and any constriction very cautiously divided. The bowel should then be drawn down a little, the constricted point carefully examined, and then returned or not, according to its condition.
Two points require a brief separate notice:—
1. In what direction is the crural arch to be divided? Not outwards certainly, on account of the vein, nor downwards, as the bone prevents that direction. Is it to be upwards or inwards? Not upwards, for such an incision would endanger the spermatic cord or round ligament, besides greatly weakening the abdominal wall by the division, partial or complete, of Poupart's ligament. Inwards then it must be; and little more need be said about it, were it not for the occasional existence of an abnormal course and distribution of the obturator artery.