THE EXTERNAL ILIAC ARTERY. 571 



made in the course of the fibres of the aponeurosis of the external oblique, is less likely to be 

 followed by a ventral hernia, but there is danger of wounding the epigastric artery, and only 

 the lower end of the vessel can be ligated. Abernethy, who first tied this artery, made his 

 incision in the course of the vessel. The abdominal muscles and transversalis fascia having 

 been cautiously divided, the peritoneum should be separated from the iliac fossa and raised 

 toward the pelvis; and on introducing the finger to the bottom of the wound, the artery may be 

 felt pulsating along the inner border of the Psoas muscle. The external iliac vein is generally 

 found on the inner side of the artery, and must be cautiously separated from it by the finger- 

 nail or handle of the knife, and the aneurism needle should be introduced on the inner side, 

 between the artery and the vein. 



Ligation of the external iliac artery has recently been performed by a transperitoneal 

 method. An incision four inches in length is made in the semilunar line, commencing about an 

 inch below the umbilicus and carried through the abdominal wall into the peritoneal cavity. 

 The intestines are then pushed upward and held out of the way by a broad abdominal retractor, 

 and an incision made through the peritoneum at the margin of the pelvis in the course of the 

 artery, and the vessel secured in any part of its course which may seem desirable to the opera- 

 tor. The advantages of this operation appear to be that if it is found necessary, the common 

 iliac artery can be ligated instead of the external iliac without extension or modification of the 

 incision ; and secondly, that the vessel can be ligated without in any way interfering with the 

 coverings of the sac. Possibly a disadvantage may exist in the greater risk of hernia after this 

 method. 



Collateral Circulation. The principal anastomoses in carrying on the collateral circulation, 

 after the application of a ligature to the external iliac, are the ilio-lumbar with the circumflex 

 iliac ; the gluteal with the external circumflex ; the obturator with the internal circumflex ; the 

 sciatic with the superior perforating and circumflex branches of the profunda artery ; and the 

 internal pudic with the external pudic. When the obturator arises from the epigastric, it is 

 supplied with blood by branches, either from the internal iliac, the lateral sacral, or the inter- 

 nal pudic. The epigastric receives its supply from the internal mammary and inferior 

 intercostal arteries, and from the internal iliac by the anastomoses of its branches with the 

 obturator. 



In the dissection of a limb eighteen years after the successful ligature of the external iliac 

 artery by Sir A. Cooper, which is to be found in Guy's Hospital Reports, vol. i. p. 50, the 

 anastomosing branches are described in three sets: An anterior set. 1, a very large branch 

 from the ilio-lumbar artery to the circumflex iliac ; 2, another branch from the ilio-lumbar, 

 joined by one from the obturator, and breaking up into numerous tortuous branches to anastomose 

 with the external circumflex ; 3, two other branches from the obturator, which passed over the 

 brim of the pelvis, communicated with the epigastric, and then broke up into a plexus to anas- 

 tomose with the internal circumflex. An internal set. Branches given off from the obturator, 

 after quitting the pelvis, which ramified among the adductor muscles on the inner side of the 

 hip-joint, and joined most freely with branches of the internal circumflex. A posterior set. 

 1, three large branches from the gluteal to the external circumflex ; 2, several branches from the 

 sciatic around the great sciatic notch to the internal and external circumflex, and the perforating 

 branches of the profunda. 



Branches. Besides several small branches to the Psoas muscle and the neigh- 

 boring lymphatic glands, the external iliac gives off two branches of considerable 

 size the 



Deep Epigastric and Deep Circumflex Iliac. 



The Deep Epigastric Artery arises from the external iliac a few lines above 

 Poupart's ligament. It at first descends to reach this ligament, and then ascends 

 obliquely along the inner margin of the internal abdominal ring, lying between 

 the transversalis fascia and peritoneum, and, continuing its course upward, it 

 pierces the transversalis fascia, and, passing over the semilunar fold of Douglas, 

 enters the sheath of the Rectus muscle. It then ascends on the posterior surface 

 of the muscle, and finally divides into numerous branches, which anastomose, 

 above the umbilicus, with the superior epigastric branch of the internal mammary 

 and with the inferior intercostal arteries (Fig. 301). The deep epigastric artery 

 bears a very important relation to the internal abdominal ring as it passes obliquely 

 upward and inward from its origin from the external iliac. In this part of its 

 course it lies along the lower and inner margin of the ring and beneath the com- 

 mencement of the spermatic cord. As it passes to the inner side of the internal 

 abdominal ring it is crossed by the vas deferens in the male and the round ligament 

 in the female. 



Branches. The branches of this vessel are the following : The cremasteric, 

 which accompanies the spermatic cord, and supplies the Cremaster muscle and 



