1772 



HUMAN ANATOMY. 



Fig. 



1494- 



Peritoneum 



Transversalis fascia 



Conjoined tendon (and Colles's ligament 



Intercolumnar fascia 



Fascia and skin' 



Deep 



epigastric 



artery 



Diagram showing coverings of complete direct inguinal hernia. 



relation to the inguinal canal as have oblique herniae, although when the peritoneal 

 pouch first forms, and before the resistance of the aponeurosis at the external ring 

 has been overcome, they usually enter the lower part of the canal, as the resistance 

 in that direction is less than it is inward, towards the rectus. They are never con- 

 genital and have no definite pre- 

 existing path. They are there- 

 fore herniae of slow development, 

 usually seen in adult life, especially 

 if the local weakness of the ab- 

 dominal wall is emphasized by 

 its laxity from general muscular 

 atrophy, or by increased intra- 

 abdominal pressure from accu- 

 mulation of fat. They are usually 

 small, globular in shape (by rea- 

 son of the shortness of the neck), 



do not, as a rule, descend into the scrotum, but remain above the crest of the 

 pubes, and when reduced go directly backward into the abdomen. The orifice in 

 the abdominal wall is easily felt, the outer edge of the rectus to its inner side, the 

 crest of the pubes below. The epigastric artery is to the outer side of this aperture, 

 but its pulsation can rarely, if ever, be felt. Macready says : the opening in the 

 posterior wall of the inguinal canal through which a direct hernia comes is much more 

 accessible to examination in the living than the internal abdominal ring, so that it is 

 quite possible, in the majority of cases, to explore the conjoined tendon with the 

 finger and ascertain the shape and size of the opening as well as the extent to which 

 the posterior wall has suffered. When a hernia is oblique, the posterior wall of the 

 canal is felt as a plane surface by the finger passed into the external ring, and its 

 attachment along the pubes can be traced. The finger is prevented from entering 

 the abdomen till it reaches the internal ring. But in direct hernia, when fully devel- 

 oped, the finger at once passes into the belly over the bare pubes, and can feel the 

 back of that bone and of the rectus muscle. No trace of the posterior wall of the 

 canal is felt nor the margin of an opening in it. All that remains is a narrow layer 

 of membrane which just fills the angle between the pubes and the rectus ; it seems 

 as if the triangular ligament had alone withstood the distending force of the hernia. In 



these cases, in which the pro- 

 FiG. 1495. trusion has done its worst, 



all the posterior wall of the 

 canal between the rectus and 

 epigastric artery has gone, 

 and the large opening has a 

 triangular figure coinciding 

 with the triangle of Hessel- 

 bach. 



If strangulation occurs, 

 it is apt to be at the exter- 

 nal ring, and the incision 

 for relief of the constriction 

 should be upward with a 

 slight inclination inward. 



Large oblique herniae 

 (scrotal), especially when of 

 long standing and in old 

 persons with relaxed abdom- 

 inal walls, may have the in- 



Plica hypogastrica 



lica epigastrica 



ique inguinal hernia 

 (external fossa) 

 ct inguinal hernia 

 (internal fossa) 



Femoral hernia 



Obturator hernia 



Plica urachi 



Supravesical fossa 



Semidiagrammatic view of posterior surface of anterior abdominal 

 showing relative positions of various forms of hernia. (After Merkel.) 



wall, 



ternal ring displaced so far towards the median line by the weight of the hernia that 

 !t occupies almost exactly the usual site of exit of a direct hernia. The epigastric 

 artery will, of course, still lie to its inner side, but cannot be felt. As a rule, how- 

 ever, a sufficient portion of the posterior wall of the inguinal canal will be left to pre- 

 serve some obliquity of the neck (Macready), by which the hernia may be recognized. 



