I. Transversalis muscle.
K. Termination of the sheath of the rectus muscle.
L1 L2 L3. The iliac, transverse and pelvic portions of the transversalis fascia.
M M. The peritonaeum lining the groin.
N. The epigastric vessels lying between the peritonaeum, M, and the transversalis fascia, L2.
O. The umbilical ligament.
P. The neck of the sac of an external inguinal hernia formed before the spermatic vessels.
Q. An interval which occasionally occurs between the umbilical ligament and the epigastric artery.
R and Q. Situations where the direct inguinal hernia occurs when, as in this case, the umbilical ligament crosses the space named the internal fossa--the triangle of Hesselbach.
S. Lower part of the right spermatic cord.
T. The bulb of the urethra.
U. External iliac vein covered by the peritonaeum.
V. External iliac artery covered by the peritonaeum.
W. Internal iliac artery.
X. Common iliac artery.
Plate 32
PLATE 33.--The External Inguinal Hernia.
A. Anterior iliac spinous process.
B. The umbilicus.
C. Fleshy part of the external oblique muscle; c, its tendon.
D. Fleshy part of the internal oblique muscle; d, its tendon.
E. Transversalis muscle; e, the conjoined tendon.
F f. The funnel-shaped sheath of the spermatic vessels covering the external hernia; upon it are seen the cremasteric fibres.
G g. The peritonaeal covering or sac of the external hernia within the sheath.
H. The external abdominal ring.
I. The crista pubis.
K k. The saphenous opening.
L. The saphena vein.
M. The femoral vein.
N. The femoral artery; n, its profunda branch.
O. The anterior crural nerve.
P. The epigastric vessels overlaid by the neck of the hernia.
Q Q. The sheath of the femoral vessels.
R. The sartorius muscle.
S. The iliacus muscle.
Plate 33
PLATE 34.--The Internal Inguinal Hernia.
The letters indicate the same parts as in Plate 33
Plate 34
COMMENTARY ON PLATES 35, 36, 37, & 38.
THE DISTINCTIVE DIAGNOSIS BETWEEN EXTERNAL AND INTERNAL INGUINAL HERNIAE, THE TAXIS, THE SEAT OF STRICTURE, AND THE OPERATION.
A comparison of the relative position of these two varieties of herniae is in ordinary cases the chief means by which we can determine their distinctive diagnosis; but oftentimes they are found to exhibit such an interchange of characters, that the name direct or oblique can no longer serve to distinguish between them. The nearer the one approaches the usual place of the other, the more likely are they to be mistaken the one for the other. An internal hernia may enter the inguinal canal, and become oblique; while an external hernia, though occupying the canal, may become direct. It is only when these herniae occur at the situations commonly described, and where they manifest their broadest contrast, that the following diagnostic signs can be observed.
The external bubonocele, H, Plate 37, G, Plate 38, when recently formed, may be detected at a situation midway between the iliac and pubic spinous processes, where it has entered the internal ring. When the hernia extends itself from this part, its course will be obliquely inwards, corresponding with the direction of the inguinal canal. While it still occupies the canal without passing through the external ring, it is rendered obscure by the restraint of the external oblique tendon; but yet a degree of fulness may be felt in this situation. When the hernia has passed the external ring, T, Plate 36, it dilates considerably, and assumes the form of an oblong swelling, H, Plate 36, behind which the spermatic vessels are situated. When it has become scrotal, the cord will be found still on its posterior aspect, while the testicle itself occupies a situation directly below the swelling.
The internal hernia, H, Plate 38, also traverses the external ring, T, where it assumes a globular shape, and sometimes projects so far inwards, over the pubes, C, as to conceal the crista of this bone. As the direction of this hernia is immediately from behind forwards, the inguinal canal near the internal ring is found empty, unswollen. The cord, Q, lies external to and somewhat over the fore part of this hernia; and the testicle does not occupy a situation exactly beneath the fundus of the sac, (as it does in the external hernia,) but is found to be placed either at its fore part or its outer side. This difference as to the relative position of the cord and testicle in both these forms of herniae, is accounted for under the supposition that whilst the external variety descends inside the sheaths of the inguinal canal, the internal variety does not. But this statement cannot apply to all cases of internal hernia, for this also occasionally enters the canal.
Both forms of inguinal herniae may exist at the same time on the same side: the external, G, Plate 38, being a bubonocele, still occupying the inguinal canal; while the internal, H, protrudes through the external ring, T, in the usual way. In this form of hernia--a compound of the oblique and direct--while the parts remain still covered by the integuments, it must be difficult to tell its nature, or to distinguish any mark by which to diagnose the case from one of the external variety, H, Plate 36, which, on entering the canal at the internal ring, protrudes at the external ring. In both cases, the swelling produced in the groin must be exactly of the same size and shape. The epigastric artery in the case where the two herniae co-exist lies between them, holding in its usual position with respect to each when occurring separately--that is, on the outer side of the internal hernia, H, and on the inner side of the external one, G; and the external hernia, G, not having descended the canal as far as the external ring, T, allows the internal hernia, H, to assume its usual position with respect to the cord, Q. [Footnote]
[Footnote: Cases of this double hernia (external and internal) have been met with by Wilmer, Arnaud, Sandifort, Richter, and others. A plurality of the same variety of hernia may also occur on the same side. A complete and incomplete external inguinal hernia existing in the one groin, is recorded by Mr. Aston Key in his edition of Sir Astley Cooper's work on Hernia. Sir Astley Cooper states his having met with three internal inguinal herniae in each inguinal region. (Ing. et Congenit. Hernire.) ]