1398 CLINICAL AND TOPOGRAPHICAL A NA TOM Y 



the posterior aspect of its so-called rings and canal, as these have to bear the early stress of a 

 commencing hernia. It is against this aspect that a piece of omentum or intestine is constantly 

 and insidiously pressing and endeavouring to make its way out. Furthermore, when either of 

 the above constituents of hernia have made their way a little farther, and got out into the ab- 

 dominal ring or into the canal, the patient is no longer sound. 



On the posterior wall are certain cords and depressions, marking off regions which corre- 

 spond to those on the surface. Thus, there are three prominent cords and three fossae 

 (fig. 1121). 



Three cords — (1) Median, or urachus; (2) lateral, or the obliterated hypogastric arteries. 



(1) ^ledian, or urachus. This interesting foetal relic, the intra-abdominal part of the 

 allantois, passes up between the apex of the bladder and the umbilicus. 



(2) The obliterated hypogastric arteries. These, the remains of vessels which during 

 foetal life carr}^ the impure blood of the foetus out to the mother through the umbilicus, run 

 up and join the urachus at the umbilicus. 



In relation to these cords are the following fossae : — (a) A medial one, between the \irachus 

 and the obliterated hypogastric artery. This corresponds, on the anterior surface, to the 

 subcutaneous inguinal (external abdominal) ring. Through this fossa comes the commonest 

 form of direct inguinal hernia. (6) Between the obliterated hypogastric artery and the inferior 

 epigastric artery, which runs upward and medially to form the lateral boundary of Hessel- 

 bach's triangle, is an intermediate fossa. This is the smallest of all. The rarer form of direct 

 hernia comes through here, (c) The lateral fossa is lateral to the inferior epigastric artery. It 

 is the most distinct of the three, from the way in which the cord or round ligament passes down 

 within a glove-like vaginal process of the transversalis fascia. This fossa corresponds to the 

 abdominal ring. 



The coverings of a direct hernia may now be considered, together with the two-fold manner 

 of exit of this hernia. It only traverses the lower part of the canal, making its way through 

 either the medial or the intermediate inguinal pouch, (i) The commonest form, coming 

 through the medial inguinal pouch, either pushes its way through or stretches before it the falx 

 inguinalis. Its coverings are: — (1) Peritoneum; (2) extra-peritoneal fat; (3) transversalis fascia; 

 (4) falx inguinalis (unless this is suddenly burst through); (5) (6) (7). At the subcutaneous 

 ring the three coverings are the same as in the oblique variety, (ii) This rarer form of direct 

 hernia comes through the intermediate inguinal pouch. As a rule, the falx inguinalis does not 

 reach over this fossa. The coverings will be the same as in the last, with two exceptions — 

 there is no falx inguinalis, and the cremasteric fascia, if well developed, will be present. 



Varieties of inguinal hernia according to the condition of the vaginal process of peritoneum. 

 — Inguinal hernice have above been classified according to their relation to the deep epigastric 

 artery. It remains to allude to the arrangement of these same hernise according to the varying 

 condition of the processus vaginalis. This pouch of peritoneum, which paves the way for the 

 passage of the testis before this organ makes its start, eventually becomes the parietal layer 

 (p. 1387) of the tunica vaginalis below, in this fashion; During the first few weeks after birth 

 the process becomes obliterated at two spots — one near the abdominal ring, and one just 

 above the testis. The obliterative process, commencing first above and descending, and then, 

 ascending from below, the shrivelling continues until nothing is left save the tunica vaginalis 

 below. The following are possible hernial results of an imperfect obliteration of the process: — 



(1) If the process does not close at all, a descending hernia is called congenital. This may 

 make its way into the scrotum. The testis is now enveloped and concealed by the hernia. 



(2) If the process is closed only above, i. e., near the abdominal ring, two varieties may be 

 met with, the infantile and the infantile encysted. In the infantile, owing to pressure above, the 

 weak septum gradually yields and forms a sac behind the unobliterated lower part of the pro- 

 cessus funiculo-vaginalis. Thus three layers of peritoneum may now be met with in an opera- 

 tion, the two of the incompletely obliterated tunica vaginalis, and the proper sac of the hernia. 

 In the encysted infantile variety the hernial pressure causes the septum to yield and form a sac 

 projecting into, not beliind, the incompletely obliterated tunica vaginalis. Here, theoretically, 

 two layers of peritoneum will be met with. Another variety of such an encysted hernia may 

 be produced by rupture, not stretching, of the above-mentioned septum. 



(3) If the processus vaginalis be closed below and not above, a patent tubular process of 

 peritoneum will lead down as far as the top of the testis. Any hernia into this process is called 

 a hernia into the funicular process. All these varieties save the congenital and hernia into the 

 funicular process are rare in practice. Other practical points are that all hernias in children and 

 young adults are probably of congenital origin, and, therefore, the weakness is often bilateral, 

 though it may not be so palpably. This applies to both sexes. Again in hernia of sudden 

 origin into the funicular process with narrow surroundings, strangulation may be very acute. 



Inguinal hernia in the female. — The inguinal canal in women is smaller and narrower than 

 in men. lii;^iiinal hiM-nia is, therefore, less common in the female sex, and occurs in patients who 

 happen to be the suljjects of an unobliterated processus vaginalis, which extends for a varying 

 distance along the round ligament, and is called the canal of Nuck. Inguinal hernia in the 

 female is, therefore, always congenital. It is, practically, always of the oblique variety, and 

 travels along the round ligament toward the labium majus. Its coverings will be the same as 

 tho.se of the obliciue variety in the male, save that the cremaster, as a distin(!t muscle, is absent, 

 and any fibres of the internal obli(iue wiiich may be present are but little developed. 



FEMORAL HERNIA 



Parts concerned in femoral hernia. — (1) Skin and superficial fascia of groin. 

 — Tho latter (consists of two layens: (a) Superficial layer of superficial fascia. — 

 Fatty, met with over tlio whole groin, and continuous with the superficial fascia 



