DIRECT INGUINAL HERNIA. 829 



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 two other varieties of oblique inguinal hernia : the congenital, and 

 infantile. 



Congenital hernia is liable to occur in those cases where the pouch of perito- 

 neum which accompanies the cord and testis in its descent in the foetus remains 

 unclosed, and communicates directly with the peritoneum. The intestine 

 descends along this pouch into the cavity of the tunica vaginalis, and lies 

 in contact with the testis. This form of hernia has no proper sac, being con- 

 tained within the tunica vaginalis. 



In infantile hernia, the hernial sac descends along the inguinal canal into 

 the scrotum, behind the pouch of peritoneum which accompanies the cord and 

 testis into the same part. The abdominal aperture of this pouch is closed, but 

 the portion contained in the inguinal canal remains unobliterated. The hernial 

 sac is consequently invested, more or less completely, by the posterior layer 

 of the tunica vaginalis, from which it is separated by a little loose areolar 

 tissue ; so that in operating upon this variety of hernia, three layers of perito- 

 neum would require division ; the first and second being the layers of the 

 tunica vaginalis, the third the anterior layer of the hernial sac. 



DIEECT INGUINAL HERNIA. 



In Direct Inguinal Hernia, the protrusion makes its way through some part 

 of the abdominal wall internal to the epigastric artery, and passes directly 

 through the abdominal parietes and external ring. At the lower part of the 

 abdominal wall is a triangular space (Hesselbach's triangle), bounded, externally, 

 by the epigastric artery ; internally, by the margin of the Rectus muscle ; 

 below, by Poupart's ligament. The conjoined tendon is stretched across the 

 inner two-thirds of this space, the remaining portion of the space being filled 

 in by the transversal is fascia. 



In some cases the hernial protrusion escapes from the abdomen on the outer 

 side of the conjoined tendon, pushing before it the peritoneum, the subserous 

 cellular tissue, and the transversalis fascia. It then enters the inguinal canal, 

 passing along nearly its whole length, and finally emerges from the external 

 ring, receiving an investment from the intercolumnar fascia. The coverings 

 of this form of hernia are precisely similar to those investing the oblique form. 



In other cases, and this is the more frequent variety, the intestine is either 

 forced through the fibres of the conjoined tendon, or the tendon is gradually 

 distended in front of it, so as to form a complete investment for it. The intes- 

 tine then enters the lower end of the inguinal canal, escapes at the external 

 ring lying on the inner side of the cord, and receives additional coverings from 

 the superficial fascia and the integument. This form of hernia has the same 

 coverings as the oblique variety, excepting that the conjoined tendon is sub- 

 stituted for the Cremaster, and the infundibuliform fascia is replaced by a part 

 of the general fascia transversalis. 



The seat of stricture in both varieties of direct hernia is most frequently at 

 the neck of the sac, or at the external ring. In that form of hernia which 

 perforates the conjoined tendon, it not unfrequently occurs at the edges of the 

 fissure through which the gut passes. In dividing the stricture, the incision 

 should in all cases be directed upwards. 



If the hernial protrusion passes into the inguinal canal, but does not escape 

 from the external abdominal ring, it forms what is called incomplete direct hernia. 

 This form of hernia is usually of small size, and in corpulent persons very 

 difficult of detection. 



Direct inguinal hernia is of much less frequent occurrence than the oblique, 



