INGUINAL HERNIA 



1397 



Site. — Midway between the anterior superior iliac spine and pubic tubercle. 

 Shape: oval, wdth the long diameter vertical. Boundaries: centre of inguinal 

 (Poupart's) ligament, about 12 mm. (| in.) below. Medially, the_ inferior 

 epigastric artery (fig. 1121); the position of this vessel, by its pulsation, is an im- 

 portant guide to the insertion of the highest sutures between the arciform fibres 

 and the inguinal ligament. Owing to the artery lying to the medial side, the 

 incision, in cutting to relieve the deep constriction of an inguinal hernia, should 

 alwaj^s be made directly upward, so as to avoid the above vessel. A large ob- 

 lique hernia may so have altered the relations of the parts, including the artery, 

 that it is difficult to decide whether the hernia is oblique or direct. The above 

 incision will be safe, because, in either case, parallel to the vessel. 

 Coverings. — There are two chief forms of inguinal hernia: — 

 A. The common form: lateral, or oblique. — Lateral, because it appears 

 (at the abdominal ring) lateral to the inferior epigastric artery. Oblique, 

 because it traverses the whole of the inguinal canal, entering it at its inlet and 

 leaving it at its outlet. This form is usually congenital in origin, and is due to 

 non-obliteration of the processus vaginaUs in infancy. 



Fig. 1121.- 



-DlSSECTION OF THE LoWER PaRT OF THE ABDOMINAL WaLL FROM WITHIN, THE 



Peritoneum having been removed. (Wood.) 



Fascia transversalis f 



Inferior epigastric 

 artery 



Abdominal (intemal 

 inguinal) ring 



Ductus (vas) deferens 

 Spermatic vessels 



Border of the poste- 

 rior part of the 

 sheath of the rec- 

 tus (fold of Doug- 

 las) 



Posterior surface of 

 rectus 



Falx inguinahs in 

 the triangle of 

 Hesselbach 



Obliterated hypo- 

 gastric artery 



Lymphatics in 

 femoral ring 



External iliac arterv 



B. Rarer form : medial, or direct. — Medial, because it appears medial to the 

 inferior epigastric artery. Direct, because, instead of making its way down the 

 whole oblique canal, it comes by a short cut, as it were, only into the lower part 

 of the canal, and then emerges by the same opening as the other. 



A. Oblique inguinal hernia. — This possesses its coverings as follows: — 



(1) At the abdominal ring, or inlet, it obtains three: — (o) Peritoneum; (6) extra-peritoneal 

 fat; (c) infundibuUform fascia, or the vaginal process of transversalis fascia prolonged at this 

 spot along the cord. 



(2) In the canal it obtains one. As it emerges beneath the lower border of the internal 

 oblique it gets some fibres from the cremaster. 



(3) At the subcutaneous ring, or outlet, the hernia obtains three, viz.: (a) Intercrura 

 fibres (intercolumnar fascia); (6) superficial fascia; and (c) skin. 



B. Direct inguinal hernia. — This does not come through the abdominal ring, but, "making 

 its way through the posterior wall of the lower third of the canal, either through the medial or 

 interrnediate inguinal fossa. Its coverings, therefore, vary slightly with its mode of exit {vide 

 infra) . 



Hitherto the two forms of inguinal hernia have been considered from the superficial aspect, 

 that in which they are met within practice. The inguinal region should also be studied as to 



