Plate 42--Figure 2

96 Commentary on plates 41 & 42.

PLATE 42, Fig. 3.--Every internal hernia, which does not rupture the peritonaeum, carries forward a sac produced anew from this membrane, whether the hernia enter the inguinal canal or not. But this is not the case with respect to the fibrous membrane which forms the fascia propria. If the hernia enter the inguinal wall immediately on the inner side of the epigastric artery, Fig. 1, Plate 42, it passes direct into the ring of the fibrous tube, 2, 2, already prepared to receive it. But when the hernia, 11, Fig. 3, Plate 42, cleaves the conjoined tendon, 6, 6, then the artery, 9, and the tube, 2, 2, remain in their usual position, while the bowel carries forward a new investment from the transversalis fascia, 5, 5. That part of the conjoined tendon which stands external to the hernia keeps the tube, 2, 2, in its proper place, and separates it from the fold of the fascia which invests the hernial sac. This is the only form in which an internal hernia can be said to be absolutely distinct from the inguinal canal and spermatic vessels. This hernia, when passing the external ring, 4, has the spermatic cord on its outer side.

Plate 42--Figure 3

PLATE 42, Fig. 4.--The external hernia, from hav­ing been originally oblique, may assume the position of a hernia originally internal and direct. The change of place exhibited by this form of hernia does not imply a change either in its original investments or in its position with respect to the epigastric artery and spermatic vessels. The change is merely caused by the weight and gravitation of the hernial mass, which bends the epigastric artery, 9*, from its first position on the inner margin of the internal ring, 1, till it assumes the place 9. In consequence of this, the internal ring of the fascia transversalis, 2, 2, is considerably widened, as it is also in Fig. 2, Plate 42. It is the inner margin of the fibrous ring which has suffered the pressure; and thus the hernia now projects directly from behind forwards, through, 4, the external ring. The conjoined tendon, 6, when weak, becomes bent upon itself. The change of place per­formed by the gravitating hernia may disturb the order and relative position of the spermatic vessels; but these, as well as the hernia, still occupy the in­guinal canal, and are invested by the spermatic fascia, 3, 3. When an internal hernia, Fig. 1, Plate 42, enters the inguinal canal, it also may descend the cord as far as the testicle, and assume in respect to this gland the same position as the external hernia. [Footnote]

[Footnote: As the external hernia, Fig. 4, Plate 42, may displace the epigastric artery inwards, so may the internal hernia, Fig. 1, Plate 42, displace the artery outwards. Mr. Lawrence, Sir Astley Cooper, Scarpa, Hesselbach, and Langenbeck, state, however, that the internal hernia does not disturb the artery from its usual position three-fourths of an inch from the exter­nal ring.]

Plate 42--Figure 4

PLATE 42, Figs. 5, 6, 7.--The form and position of the inguinal canal varies according to the sex and age of the individual. In early life, Fig. 6, the internal ring is situated nearly opposite to the external ring, 4. As the pelvis widens gradually in the advance to adult age, Fig. 5, the canal becomes oblique as to po­sition. This obliquity is caused by a change of place, performed rather by the internal than the external ring. [Footnote] The greater width of the female pelvis than of the male, renders the canal more oblique in the former; and this, combined with the circumstance that the female inguinal canal, Fig. 7, merely trans­mits the round ligament, 14, accounts anatomically for the fact, that this sex is less liable to the occur­rence of rupture in this situation.

[Footnote: M. Velpeau (Nouveaux Elemens de med. Operat.) states the length of the inguinal canal in a well-formed adult, measured from the internal to the external ring, to be 1-1/2 or 2 inches, and 3 inches including the rings; but that in some individuals the rings are placed nearly opposite; whilst in young subjects the two rings nearly always correspond. When, in company with these facts, we recollect how much the parts are liable to be disturbed in ruptures, it must be evident that their relative position cannot be exactly ascertained by measure­ment, from any given point whatever. The judgment alone must fix the general average.]

Plate 42--Figure 5

Plate 42--Figure 6

Plate 42--Figure 7

COMMENTARY ON PLATES 43 & 44.

THE DISSECTION OF FEMORAL HERNIA, AND THE SEAT OF STRICTURE.

Whilst all forms of inguinal herniae escape from the abdomen at places situated immediately above Poupart's ligament, the femoral hernia, G, Fig. 1, Plate 43, is found to pass from the abdomen immedi­ately below this structure, A I, and between it and the horizontal branch of the pubic bone. The inguinal canal and external abdominal ring are parts concerned in the passage of inguinal herniae, whether oblique or direct, external or internal; whilst the femoral canal and saphenous opening are the parts through which the femoral hernia passes. Both these orders of parts, and of the herniae connected with them respectively, are, however, in reality situated so closely to each other in the inguino-femoral region, that, in order to understand either, we should, examine both at the same time comparatively.

The structure which is named Poupart's ligament in connexion with inguinal herniae, is named the femoral or crural arch (Gimbernat) in relation to femoral hernia. The simple line, therefore, described by this ligament explains the narrow interval which separates both varieties of the complaint. So small is the line of separation described between these herniae by the ligament, that this (so to express the idea) stands in the character of an arch, which, at the same time, supports an aqueduct (the inguinal canal) and spans a road (the femoral sheath.) The femoral arch, A I, Fig. 1, Plate 43, extends between the an­terior superior iliac spinous process and the pubic spine. It connects the aponeurosis of the external oblique muscle, D d, Fig. 2, Plate 44, with F, the fascia lata. Immediately above and below its pubic extrem­ity appear the external ring and the saphenous open­ing. On cutting through the falciform process, F, Fig. 1, Plate 44, we find Gimbernat's ligament, R, a structure well known in connexion with femoral hernia. Gimbernat's ligament consists of tendinous fibres which connect the inner end of the femoral arch with the pectineal ridge of the os pubis. The shape of the ligament is acutely triangular, corres­ponding to the form of the space which it occupies. Its apex is internal, and close to the pubic spine; its base is external, sharp and concave, and in apposition with the sheath of the femoral vessels. It measures an inch, more or less, in width, and it is broader in the male than in the female--a fact which is said to account for the greater frequency of femoral hernia in the latter sex than in the former, (Monro.) Its strength and density also vary in different individuals. It is covered anteriorly by, P, Fig. 1, Plate 44, the upper cornu of the falciform process; and behind, it is in connexion with, k, the conjoined tendon. This tendon is inserted with the ligament into the pecti­neal ridge. The falciform process also blends with the ligament; and thus it is that the femoral hernia, when constricted by either of these three structures, may well be supposed to suffer pressure from the three together.

A second or deep femoral arch is occasionally met with. This structure consists of tendinous fibres, lying deeper than, but parallel with, those of the superficial arch. The deep arch spans the femoral sheath more closely than the superficial arch, and occupies the interval left between the latter and the sheath of the vessels. When the deep arch exists, its inner end blends with the conjoined tendon and Gimbernat's ligament, and with these may also con­strict the femoral hernia.