Surgical Anatomy Part 31

[Ill.u.s.tration: Abdomen, showing bone, blood vessels and other internal organs.]

Plate 41--Figure 7

PLATE 41, Fig. 8.--When the serous spermatic tube only closes at the internal ring, as seen at 1, Fig. 4, Plate 41, if a hernia afterwards pouch the peritonaeum at this part, and enter the inguinal ca.n.a.l, we shall then have the form of hernia, Fig. 8, Plate 41, termed infantile.

Two serous sacs will be here found, one within the cord, 13, and communicating with the tunica v.a.g.i.n.alis, the other, 11, containing the bowel, and being received by inversion into the upper extremity of the first. Thus the infantile serous ca.n.a.l, 13, receives the hernial sac, 11. The inguinal ca.n.a.l and cord may become multicapsular, as in Fig. 8, from various causes, each capsule being a distinct serous membrane.

First, independent of hernial formation, the original serous tube may become interruptedly obliterated, as in Plate 40, Fig. 2. Secondly, these sacs may persist to adult age, and have a hernial sac added to their number, whatever this may be. Thirdly, the original serous tube, 13, Fig. 8, may persist, and after having received the hernial sac, 11, the bowel may have been reduced, leaving its sac behind it in the inguinal ca.n.a.l; the neck of this sac may have been obliterated by the pressure of a truss, a second hernia may protrude at the point 1, and this may be received into the first hernial sac in the same manner as the first was received into the original serous infantile tube. The possibility of these occurrences is self-evident, even if they were never as yet experienced. [Footnote]

[Footnote: According to Mr. Lawrence and M. Cloquet, most of the serous cysts found around hernial tumours are ancient sacs obliterated at the neck, and adhering to the new swelling (opera cit.)]

[Ill.u.s.tration: Abdomen, showing bone, blood vessels and other internal organs.]

Plate 41--Figure 8

PLATE 42, Fig. 1.--The epigastric artery, 9, being covered by the fascia transversalis, can lend no support to the internal ring, 2, 2, nor to the tube prolonged from it. The herniary bowel may, therefore, dilate the peritonaeum immediately on the inner side of the artery, and enter the inguinal ca.n.a.l. In this way the hernia, 11, although situated internal to the epigastric artery, a.s.sumes an oblique course through the ca.n.a.l, and thus closely simulates the external variety of inguinal hernia, Fig. 7, Plate 41. If the hernia enter the ca.n.a.l, as represented in Fig. 1, Plate 42, it becomes invested by the same structures, and a.s.sumes the same position in respect to the spermatic vessels, as the external hernia.

[Ill.u.s.tration: Abdomen and s.c.r.o.t.u.m, showing bone, blood vessels and other internal organs.]

Plate 42--Figure 1

PLATE 42, Fig. 2.--The hernial sac, 11, which entered the ring of the fibrous tube, 2, 2, at a point immediately internal to the epigastric artery, 9, may, from having been at first oblique, as in Fig. 1, Plate 42, a.s.sume a direct position. In this case, the ring of the fibrous tube, 2, 2, will be much widened; but the artery and spermatic vessels will remain in their normal position, being in no wise affected by the gravitating hernia. If the conjoined tendon, 6, be so weak as not to resist the gravitating force of the hernia, the tendon will become bent upon itself. If the umbilical cord, 10, be side by side with the epigastric artery at the time that the hernia enters the mouth of the fibrous tube, then, of course, the cord will be found external. If the cord lie towards the p.u.b.es, apart from the vessel, the hernia may enter the fibrous tube between the cord, 10, and artery, 9. [Footnote:] It is impossible for any internal hernia to a.s.sume the congenital form, because the neck of the original serous spermatic tube, 11, Fig. 2, Plate 41, being external to the epigastric artery, 9, cannot be entered by the hernia, which originates internally to this vessel.

[Footnote: M. Cloquet states that the umbilical cord is always found on the inner side of the external hernia. Its position varies in respect to the internal hernia, (op. cit. prop. 52.)]

[Ill.u.s.tration: Abdomen and s.c.r.o.t.u.m, showing bone, blood vessels and other internal organs.]

Plate 42--Figure 2

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 ca.n.a.l 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 pa.s.ses 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 ca.n.a.l and spermatic vessels. This hernia, when pa.s.sing the external ring, 4, has the spermatic cord on its outer side.

[Ill.u.s.tration: Abdomen and s.c.r.o.t.u.m, showing bone, blood vessels and other internal organs.]

Plate 42--Figure 3

PLATE 42, Fig. 4.--The external hernia, from having been originally oblique, may a.s.sume 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 ma.s.s, which bends the epigastric artery, 9*, from its first position on the inner margin of the internal ring, 1, till it a.s.sumes 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 ca.n.a.l, and are invested by the spermatic fascia, 3, 3. When an internal hernia, Fig. 1, Plate 42, enters the inguinal ca.n.a.l, it also may descend the cord as far as the t.e.s.t.i.c.l.e, and a.s.sume 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.]

[Ill.u.s.tration: Abdomen and s.c.r.o.t.u.m, showing bone, blood vessels and other internal organs.]

Plate 42--Figure 4

PLATE 42, Figs. 5, 6, 7.--The form and position of the inguinal ca.n.a.l varies according to the s.e.x 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 ca.n.a.l 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 ca.n.a.l more oblique in the former; and this, combined with the circ.u.mstance that the female inguinal ca.n.a.l, Fig. 7, merely transmits the round ligament, 14, accounts anatomically for the fact, that this s.e.x 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 ca.n.a.l 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.]

[Ill.u.s.tration: Abdomen and s.c.r.o.t.u.m, showing bone, blood vessels and other internal organs.]

Plate 42--Figure 5

[Ill.u.s.tration: Abdomen and s.c.r.o.t.u.m, showing bone, blood vessels and other internal organs.]

Plate 42--Figure 6

[Ill.u.s.tration: Abdomen, showing bone, blood vessels and other internal organs.]

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 pa.s.s from the abdomen immediately below this structure, A I, and between it and the horizontal branch of the pubic bone. The inguinal ca.n.a.l and external abdominal ring are parts concerned in the pa.s.sage of inguinal herniae, whether oblique or direct, external or internal; whilst the femoral ca.n.a.l and saphenous opening are the parts through which the femoral hernia pa.s.ses. 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 ca.n.a.l) 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 s.p.a.ce 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 s.e.x 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.

The sheath, e f, of the femoral vessels, E F, Fig. 1, Plate 43, pa.s.ses from beneath the middle of the femoral arch. In this situation, the iliac part of the fascia lata, F G, Fig. 2, Plate 44, covers the sheath.

Its inner side is bounded by Gimbernat's ligament, R, Fig. 1, Plate 44, and F, the falciform edge of the saphenous opening. On its outer side are situated the anterior crural nerve, and the femoral parts of the psoas and iliacus muscles. Of the three compartments into which the sheath is divided by two septa in its interior, the external one, E, Fig. 1, Plate 43, is occupied by the femoral artery; the middle one, F, by the femoral vein; whilst the inner one, G, gives pa.s.sage to the femoral lymphatic vessels; and occasionally, also, a lymphatic body is found in it. The inner compartment, G, is the femoral ca.n.a.l, and through it the femoral hernia descends from the abdomen to the upper and forepart of the thigh. As the ca.n.a.l is the innermost of the three s.p.a.ces inclosed by the sheath, it is that which lies in the immediate neighbourhood of the saphenous opening, Gimbernat's ligament, and the conjoined tendon, and between these structures and the femoral vein.

The sheath of the femoral vessels, like that of the spermatic cord, is infundibuliform. Both are broader at their abdominal ends than elsewhere. The femoral sheath being broader above than below, whilst the vessels are of a uniform diameter, presents, as it were, a surplus s.p.a.ce to receive a hernia into its upper end. This s.p.a.ce is the femoral or crural ca.n.a.l. Its abdominal entrance is the femoral or crural ring.

The femoral ring, H, Fig. 2, Plate 43, is, in the natural state of the parts, closed over by the peritonaeum, in the same manner as this membrane shuts the internal inguinal ring. There is, however, corresponding to each ring, a depression in the peritonaeal covering; and here it is that the bowel first forces the membrane and forms of this part its sac.

On removing the peritonaeum from the inguinal wall on the inner side of the iliac vessels, K L, we find the horizontal branch of the os pubis, and the parts connected with it above and below, to be still covered by what is called the subserous tissue. The femoral ring is not as yet discernible on the inner side of the iliac vein, K; for the subserous tissue being stretched across this aperture masks it. The portion of the tissue which closes the ring is named the crural septum, (Cloquet.) When we remove this part, we open the femoral ring leading to the corresponding ca.n.a.l. The ring is the point of union between the fibrous membrane of the ca.n.a.l and the general fibrous membrane which lines the abdominal walls external to the peritonaeum. This account of the continuity between the ca.n.a.l and abdominal fibrous membrane equally applies to the connexion existing between the general sheath of the vessels and the abdominal membrane. The difference exists in the fact, that the two outer compartments of the sheath are occupied by the vessels, whilst the inner one is vacant. The neck or inlet of the hernial sac, H, Fig. 2, Plate 43, exactly represents the natural form of the crural ring, as formed in the fibrous membrane external to, or (as seen in this view) beneath the peritonaeum.

The femoral ring, H, is girt round on all sides by a dense fibrous circle, the upper arc being formed by the two femoral arches; the outer arc is represented by the septum of the femoral sheath, which separates the femoral vein from the ca.n.a.l; the inner arc is formed by the united dense fibrous bands of the conjoined tendon and Gimbernat's ligament; and the inferior arc is formed by the pelvic fascia where this pa.s.ses over the pubic bone to unite with the under part of the femoral ca.n.a.l and sheath. The ring thus bound by dense resisting fibrous structure, is rendered sharp on its pubic and upper sides by the salient edges of the conjoined tendon and Gimbernat's ligament, &c. From the femoral ring the ca.n.a.l extends down the thigh for an inch and a-half or two inches in a tapering form, supported by the pectineus muscle, and covered by the iliac part of the fascia lata. It lies side by side with the saphenous opening, but does not communicate with this place. On a level with the lower cornu of the saphenous opening, the walls of the ca.n.a.l become closely applied to the femoral vessels, and here it may be said to terminate.

The bloodvessels which pa.s.s in the neighbourhood of the femoral ca.n.a.l are, 1st. the femoral vein, F, Fig. 1, Plate 43, which enclosed in its proper sheath lies parallel with and close to the outer side of the pa.s.sage. 2nd, Within the inguinal ca.n.a.l above are the spermatic vessels, resting on the upper surface of the femoral arch, which alone separates them from the upper part or entrance of the femoral ca.n.a.l. 3rd, The epigastric artery, F, Fig. 2, Plate 43, which pa.s.ses close to the outer and upper border of, H, the femoral ring. This vessel occasionally gives off the obturator artery, which, when thus derived, will be found to pa.s.s towards the obturator foramen, in close connexion with the ring; that is, either descending by its outer border, G*, between this point and the iliac vein, K; or arching the ring, G, so as to pa.s.s down close to its inner or pubic border. In some instances, the vessel crosses the ring; a vein generally accompanies the artery. These peculiarities in the origin and course of the obturator artery, especially that of pa.s.sing on the pubic side of the ring, behind Gimbernat's ligament and the conjoined tendon, E H, are fortunately very rare.

As the course to be taken by the bowel, when a femoral hernia is being formed, is through the crural ring and ca.n.a.l, the structures which have just now been enumerated as bounding this pa.s.sage, will, of course, hold the like relation to the hernia. The manner in which a femoral hernia is formed, and the way in which it becomes invested in its descent, may be briefly stated thus: The bowel first dilates the peritonaeum opposite the femoral ring, H, Fig. 2, Plate 43, and pushes this membrane before it into the ca.n.a.l. This covering is the hernial sac. The crural septum has, at the same time, entered the ca.n.a.l as a second investment of the bowel. The hernia is now enclosed by the sheath, G, Fig. 1, Plate 43, of the ca.n.a.l itself. [Footnote 1] Its further progress through the saphenous opening, B F, Fig. 1, Plate 44, must be made either by rupturing the weak inner wall of the ca.n.a.l, or by dilating this part; in one or other of these modes, the herniary sac emerges from the ca.n.a.l through the saphenous opening. In general, it dilates the side of the ca.n.a.l, and this becomes the fascia propria, B G. If it have ruptured the ca.n.a.l, the hernial sac appears devoid of this covering. In either case, the hernia, increasing in size, turns up over the margin of F, the falciform process, [Footnote 2] and ultimately rests upon the iliac fascia lata, below the pubic third of Poupart's ligament. Sometimes the hernia rests upon this ligament, and simulates, to all outward appearance, an oblique inguinal hernia. In this course, the femoral hernia will have its three parts--neck, body, and fundus--forming nearly right angles with each other: its neck [Footnote 3] descends the crural ca.n.a.l, its body is directed to the pubis through the saphenous opening, and its fundus is turned upwards to the femoral arch.

[Footnote 1: The sheath of the ca.n.a.l, together with the crural septum, const.i.tutes the "fascia propria" of the hernia (Sir Astley Cooper). Mr.

Lawrence denies the existence of the crural septum.]

[Footnote 2: The "upper cornu of the saphenous opening," the "falciform process" (Burns), and the "femoral ligament" (Hey), are names applied to the same part. With what difficulty and perplexity does this impenetrable fog of surgical nomenclature beset the progress of the learner!]

[Footnote 3: The neck of the sac at the femoral ring lies very deep, in the undissected state of the parts (Lawrence).]