OBLIQUE INGUINAL HERNIA. 1051 



fascia, Cremaster muscle, infundibuliform fascia, subserous areolar tissue, and 

 peritoneum. 



This form of hernia lies in front of the vessels of the spermatic cord and 

 seldom extends below the testis, on account of the intimate adhesion of the cover- 

 ings of the cord to the tunica vaginalis. 



The seat of stricture in oblique inguinal hernia is either at the external ring, 

 in the inguinal canal, caused by the fibres of the Internal oblique or Trans- 

 versalis ; or at the internal ring, most frequently in the latter situation. If it is 

 situated at the external ring, the division of a few fibres at one point of its 

 circumference is all that is necessary for the replacement of the hernia. If 

 in the inguinal canal or at the internal ring, it may be necessary to divide the 

 aponeurosis of the External oblique so as to lay open the inguinal canal. In 

 dividing the stricture the direction of the incision should be upward. 



When the intestine passes along the inguinal canal and escapes from the 

 external ring into the scrotum, it is called complete oblique inguinal or scrotal 

 hernia. If the intestine does not escape from the external ring, but is retained 

 in the inguinal canal, it is called incomplete inguinal hernia, or bubonocele. In 

 each of these cases the coverings which invest it will depend upon the extent to 

 which it descends in the inguinal canal. 



There are some other varieties of oblique inguinal hernia depending upon con- 

 genital defects in the processus vaginalis. The testicle in its descent from the 

 abdomen into the scrotum is preceded by a pouch of peritoneum, which about 

 the period of birth becomes shut off from the general peritoneal cavity by a closure 

 of that portion of the pouch which extends from the internal abdominal ring to 

 near the upper part of the testicle, the lower portion of the pouch remaining per- 

 sistent as the tunica vaginalis. It would appear that this closure commences at 

 two points viz. at the internal abdominal ring and at the top of the epididymis 

 and gradually extends until, in the normal condition, the whole of the inter- 

 vening portion is converted into a fibrous cord. From failure in the completion 

 of this process variations in the relation of the hernial protrusion to the 

 testicle and tunica vaginalis are produced, which constitute distinct varieties 

 of inguinal hernia, and which have received separate names and are of surgical 

 importance. These are congenital, infantile, encysted, and hernia of the funicu- 

 lar process. 



Congenital Hernia (Fig. 584, B). Where the pouch of peritoneum which pre- 

 cedes the cord and testis in its descent remains patent throughout and is unclosed 

 at any point, the cavity of the tunica vaginalis communicates directly with the 

 peritoneum. The intestine descends along this pouch into the cavity of the tunica 

 vaginalis, which constitutes the sac of the hernia, and the gut lies in contact with 

 the testicle. 



Infantile and Encysted Hernia. Where the pouch of peritoneum is occluded 

 at the internal ring only, and remains patent throughout the rest of its extent, 

 two varieties of oblique inguinal hernia may be produced, which have received 

 the names of infantile and encysted hernia. In the infantile form (Fig. 584, c) 

 the bowel, pressing upon the septum and the peritoneum in its immediate 

 neighborhood, causes it to yield and form a sac, which descends behind the 

 tunica vaginalis, so that in front of the bowel there are three layers of per- 

 itoneum, the two layers of the tunica vaginalis and its own sac. In the encysted 

 form (Fig. 584, D) pressure in the same position namely, at the occluded spot in 

 the pouch causes the septum to yield and form a sac which projects into and not 

 behind the tunica vaginalis, as in the infantile form, and thus it constitutes a sac 

 within a sac, so that in front of the bowel there are two layers of peritoneum one 

 layer of the tunica vaginalis and its own sac. 



Hernia into the Funicular Process (Fig. 584, E). Where the pouch of perito- 

 neum is occluded at the lower point only that is, just above the testicle the 

 intestine descends into the pouch of peritoneum as far as the testicle, but is pre- 

 vented from entering the sac of the tunica vaginalis by the septum which has 



