The Surgical Anatomy of Inguinal Hernia. 



Dissection (fig. 380). For the dissection of the parts concerned in inguinal hernia, a male 

 subject, free from fat, should always be selected. The body should be placed in the prone posi- 

 tion, the abdomen and pelvis raised by means of blocks placed beneath them, and the lower 

 extremities rotated outwards, so as to make the parts as tense as possible. If the abdominal 

 walls are flaccid, the cavity of the abdomen should be inflated by an aperture through the umbi- 

 licus. An incision should be made along the middle line, from the umbilicus to the pubes, and 

 continued along the front of the scrotum ; and a second incision, from the anterior superior spine 

 of the ilium to just below the umbilicus. These incisions should divide the integument ; and the 

 triangular-shaped flap included between them should be reflected downwards and outwards, when 

 the superficial fascia will be exposed. 



The superficial fascia in this region consists of two layers, .between which are 

 found the superficial vessels and nerves, and the inguinal lymphatic glands. 



The superficial layer is thick, areolar in texture, containing adipose tissue in 

 its meshes, the quantity of which varies in different subjects. Below, it passes 

 over Poupart's ligament, and is continuous with the outer layer of the superficial 

 fascia of the thigh. This fascia is continued as a tubular prolongation around 

 the outer surface of the cord and testis. In this situation, it changes its character ; 

 it becomes thin, destitute of adipose tissue, and of a pale reddish color, and 

 assists in forming the dartos. From the scrotum, it may be traced backwards to 

 be continuous with the superficial fascia of the perineum. This layer should be 

 removed, by dividing it across in the same direction as the external incision, and 

 reflecting it downwards and outwards, when the following vessels and nerves will 

 be exposed : 



The superficial epigastric, circumflex iliac, and external pudic vessels ; the ter- 

 minal filaments of the ilio-hypogastric and ilio-inguinal nerves ; and the upper 

 chain of inguinal lymphatic glands. 



The superficial epigastric artery crosses Poupart's ligament, and ascends obliquely 

 towards the ' umbilicus, lying midway between the spine of the ilium and the 

 pubes. It supplies the integument, and anastomoses with the deep epigastric. 

 This vessel is a branch of the common femoral artery, and pierces the fascia lata, 

 below Poupart's ligament. Its accompanying vein empties itself into the internal 

 saphenous, piercing previously the cribriform fascia. 



The superficial external pudic artery passes transversely inwards across the 

 spermatic cord, and supplies the integument of the hypogastric region, and of the 

 penis and scrotum. This vessel is usually divided in the first incision made in the 

 operation for inguinal hernia, and occasionally requires the application of a ligature 

 to suppress the hemorrhage. 



The circumflex iliac artery passes outwards towards the crest of the ilium. The 

 veins accompanying the latter vessels are usually much larger than the arteries ; 

 they terminate in the internal saphenous vein. 



Lymphatic vessels are found, taking the same course as the bloodvessels ; they 

 return the lymph from the superficial structures in the lower part of the abdomen, 

 the scrotum, penis, and external surface of the buttock, and terminate in a small 

 chain of lymphatic glands, three or four in number, which lie on a level with. 

 Poupart's ligament. 



Nerves. The terminal branch of the ilio-inguinal nerve emerges at the external 

 abdominal ring ; and the hypogastric branch of the ilio-hypogastric nerve perfo- 

 rates the aponeurosis of the external oblique above and to the outer side of the 

 external ring. 



The Deep layer of superficial fascia should be divided across in the same 

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