682 THE VASCULAR SYSTEMS 



Surface Marking. The surface line indicating the course of the external iliac artery has 

 been already given (see page 671). 



Applied Anatomy. The application of a ligature to the external iliac may be required in 

 cases of aneurism of the femoral artery or for a wound of the artery. This vessel may be secured 

 in any part of its course, excepting near its upper end, which is to be avoided on account of the 

 proximity of the internal iliac, and near its lower end, which should also be avoided, on account 

 of the proximity of the deep epigastric and circumflex iliac vessels. The patient having been 

 placed in the supine position, an incision should be made, commencing below at a point about 

 three-quarters of an inch above Poupart s ligament, and a little external to its middle, and run- 

 ning upward and outward, parallel to Poupart's ligament, to a point one inch internal and one 

 inch above the anterior superior spine of the ilium. When the artery is deeply seated more 

 room will be required, and may be obtained by curving the incision from the point last named 

 inward toward the umbilicus for a short distance. Another mode of ligating the vessel is the 

 plan advocated by Sir Astley Cooper, by making an incision close to Poupart's ligament from 

 about half an inch outside of the external abdominal ring to one inch internal to the anterior 

 superior spine of the ilium. This incision, being made in the course of the fibres of the aponeu- 

 rosis 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. Aber- 

 nethy, 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 sepa- 

 rated 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 is performed by a transperitoneal method. An incision 

 four inches in length is made in the semilunar line, commencing about an inch below the um- 

 bilicus 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 is 

 made through the peritoneum at the brim of the pelvis in the course of the artery, and the 

 vessel is secured in any part of its course which may seem desirable to the operator. The advan- 

 tages 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 of an 

 aneurism. 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 ilioliimbar 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 internal 

 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. 1 



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

 boring lymph nodes, the external iliac gives off two branches of considerable 

 size the deep epigastric and deep circumflex iliac arteries. 



The deep epigastric artery (a. epigastrica inferior) (Fig. 473) arises from 

 the external iliac above Poupart's ligament. It curves forward below the peri- 

 toneum, and then ascends obliquely along the inner margin of the internal ab- 

 dominal ring f lying between the transversalis fascia and peritoneum; continuing 

 its course upward, it pierces the transversalis fascia, and passing over the semi- 

 lunar fold of Douglas, ascends between the Rectus and the posterior lamella of 

 its aponeurotic sheath. It finally divides into numerous branches which anasto- 

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

 mammary and with the lower intercostal arteries (Fig. 459). As the deep epi- 

 gastric artery passes obliquely upward and inward from its origin it lies along the 

 lower and inner margin of the internal abdominal ring and behind the commence- 

 ment of the spermatic cord. This part of the vessel is crossed by the vas deferens 

 in the male and the round ligament of the uterus in the female. 



1 Sir Astley Cooper describes the dissection of a limb eighteen years after successful ligation of the external 

 iliac artery in Vol. I of Guy's Hospital Reports. 



