EXTERNAL ILIAC. 517 



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

 named inwards towards the umbilicus for a short distance ; or, if the lower part of the artery is 

 to be reached, the surgeon may commence the incision nearer the inner end of Poupart's liga- 

 ment, taking care to avoid the epigastric artery. Abernethy, who first tied this artery, made 

 his incision in the course of the vessel. The precise line of incision selected is of less moment, 

 provided an easy access to the deeper parts is secured. The abdominal muscles and transver- 

 salis fascia having been cautiously divided, the peritoneum should be separated from the iliac 

 fossa and pushed towards 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 fouod 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 vein. 



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; the internal 

 pudic with the external pudic, and with the internal circumflex. 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 mam- 

 mary 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. page 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 anasto- 

 mose 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 anastomose 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 per- 

 forating branches of the profunda. 



Branches. Besides several small branches to the Psoas muscles and the 

 neighboring lymphatic glands, the external iliac gives off two branches of con- 

 siderable size, the 



Epigastric. Circumflex iliac. 



The epigastric artery arises from the external iliac, a few lines above Pou- 

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

 obliquely inwards between the peritoneum and transversalis fascia, to the mar- 

 gin of the sheath of the Rectus muscle. Having perforated the sheath near its 

 lower third, it runs vertically upwards behind the Rectus, to which it is dis- 

 tributed, dividing into numerous branches, which anastomose above the umbili- 

 cus with the terminal branches of the internal mammary and inferior intercostal 

 arteries. It is accompanied by two veins, which usually unite into a single 

 trunk before their termination in the external iliac vein. As this artery 

 ascends from Poupart's ligament to the Rectus, it lies behind the inguinal 

 canal, to the inner side of the internal abdominal ring, and immediately above 

 the femoral ring. The vas deferens in the male, and the round ligament in the 

 female, cross behind the artery in descending into the pelvis. 



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

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

 anastomosing with the spermatic artery; a pubic branch, which runs across 

 Poupart's ligament, and then descends behind the pubes to the inner side of the 

 femoral ring, and anastomoses with offsets from the obturator artery ; muscular 

 branches, some of which are distributed to the abdominal muscles and peritoneum, 

 anastomosing with the lumbar and circumflex iliac arteries; others perforate 

 the tendon of the External Oblique and supply the integument, anastomosing 

 with branches of the external epigastric. 



Peculiarities. The origin of the epigastric may take place from any part of the external iliac 

 between Poupart'? ligament and two inches and a half above it; or it may arise below this liga- 

 ment, from the femoral, or from the deep femoral. 



