J318 THE ORGANS OF DIGESTION 



the two layers of the tunica vaginalis and its own sac. In the encysted form (Fig. 1061) pressure 

 at the occluded spot causes the septum to yield and form a sac which projects into the tunica 

 vaginalis, forming thus a sac within a sac, so that in front of the bowel there are two layers of 

 peritoneum, one from the tunica vaginalis and one from its own sac. 



Where the processus vaginalis is occluded at the lower point only, i. e., just above the testis, 

 the intestine descends into the pouch of peritoneum as far as the testis, but is prevented from 

 entering the sac of the tunica vaginalis by the septum which has formed between it and the 

 pouch. This is known as hernia into the funicular process; it resembles the congenital form 

 except that instead of enveloping the testis it lies above it. 



In direct inguinal hernia the protrusion makes its way through some part of Hesselbach's 

 triangle, either through (a) the outer part, where only extraperitoneal tissue and transversalis 

 fascia intervene between the peritoneum and the aponeurosis of the External oblique; or through 

 (b) the conjoined tendon which stretches across the inner two-thirds of the triangle between the 

 artery and the middle line. In the former the hernial protrusion escapes from the abdomen on 

 the outer side of the conjoined tendon, pushes before it the peritoneum, extraperitoneal tissue, 

 and transversalis fascia, and enters the inguinal canal. It passes along nearly the whole length 

 of the canal and finally emerges from the external ring, receiving an investment from the inter- 

 columnar fascia. The coverings of this form of hernia are similar to those of the oblique form, 

 except that a portion derived from the general layer of transversalis fascia replaces the infun- 

 dibuliform fascia. 



In the second form, which is the more frequent, the hernia 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 com- 

 plete investment for it. The intestine 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 

 external spermatic fascia, the superficial fascia, and the integument. The coverings of this form, 

 therefore, differ from those of the oblique form in that the conjoined tendon is substituted for the 

 cremaster, and the infundibuliform fascia is replaced by a portion of the general layer of the 

 transversalis fascia. 



The seat of stricture in both varieties of direct hernia is usually found either at the neck of the 

 sac or at the external ring. In that form which perforates the conjoined tendon it not infre- 

 quently occurs at the edges of the fissure through which the gut passes. In all cases of inguinal 

 hernia, whether direct or oblique, it is proper to divide the stricture directly upward; by cutting 

 in this direction the incision is made parallel to the deep epigastric artery external to it in the 

 oblique variety, internal to it in the direct form of hernia; all chance of wounding the vessel is 

 thus avoided. Direct inguinal hernia is of much less frequent occurrence than the oblique, and 

 is found more often in men than in women. The main differences in position between it and 

 the oblique form are: (a) it is placed over the pubis and not in the course of the inguinal canal; 

 (b) the deep epigastric artery runs on the outer or iliac side of the neck of the sac; and (c) the 

 spermatic cord lies along its external and posterior sides, not directly behind it, as in oblique 

 inguinal hernia. 



Femoral Hernia. In femoral hernia the protrusion of the intestine takes place through 

 the crural ring. As already described (p. 504), this ring is closed by the septum crurale, a 

 partition of modified extraperitoneal tissue; it is, therefore, a weak spot in the abdominal wall, 

 and especially in the female, where the ring is larger and where profound changes are produced 

 in the tissues of the abdomen by pregnancy. Femoral hernia is, therefore, more common in 

 women than in men. 



When a portion of intestine is forced through the femoral ring it carries before it a pouch of 

 peritoneum which forms the hernial sac. It receives an investment from the extraperitoneal 

 tissue or septum crurale and descends along the femoral canal, or inner compartment of the 

 sheath of the femoral vessels, as far as the saphenous opening; at this point it changes its course, 

 being prevented from extending farther down the sheath on account of the narrowing of the 

 latter, and its close contact with the vessels, and also from the close attachment of the superficial 

 fascia and femoral sheath to the lower part of the circumference of the saphenous opening. 

 The tumor is consequently directed forward, pushing before it the cribriform fascia, and then 

 curves upward over Poupart's ligament and the lower part of the External oblique, being covered 

 by the superficial fascia and integument. While the hernia is contained in the femoral canal it is 

 usually of small size owing to the resisting nature of the surrounding parts, but when it escapes 

 from the saphenous opening into the loose areolar tissue of the groin it becomes considerably 

 enlarged. The direction taken by a femoral hernia in its descent is at first downward, then for- 

 ward and upward; in the application of taxis for the reduction of a femoral hernia, therefore, 

 pressure should be directed in the reverse order. 



The coverings of a femoral hernia, from within outward, are peritoneum, septum crurale, 

 femoral sheath, cribriform fascia, superficial fascia, and integument. Sir Astley Cooper has 

 described an investment for femoral hernia under the name of fascia propria, lying immediately 

 external to the peritoneal sac but frequently separated from it by some adipose tissue. Surgi- 

 cally it is important to remember the frequent existence of this layer on account of the ease with 



