372 The External Iliac Artery 



The accompanying vein has to cross over the external iliac artery 

 to enter the main vein (v. p. 353). 



Migration of the external iliac artery. A curved incision of 3 or 

 4 in., with the convexity downwards and outwards, is made from a 

 little above and to the outer side of the middle of Poupart's ligament 

 to just above the front of the iliac crest. Integuments, muscles, and 

 fascia are divided, to the length of the skin wound, as detailed on 

 p. 369. The peritoneum is then gently drawn up, and the artery is felt 

 pulsating on the pubic ramus. The trunk is followed up for an inch, 

 and is then freed of a little connective tissue which attaches it to 

 its vein and to the sheath of the psoas. The aneurysm-needle is passed 

 from the venous, the inner, side. (For line of incision v. p. 295.) 



In aged persons, and in those with diseased capillaries, the external 

 iliac artery is elongated and tortuous, and sometimes drops from the 

 inner side of the psoas to form a considerable loop into the true pelvis. 



Collateral circulation. The deep epigastric would bring in 

 blood from its fellow of the opposite side, and from the obturator, by 

 the anastomosis behind the pubes ; from the spermatic (aortic) through 

 the cremasteric branch ; from the lumbar and Iowa" intercostals, and 

 from the internal mammary (p. 1 56). The deep circumflexa would help 

 by its communications with the iliac branch of the ilio-lumbar, and 

 with thelower lumbar arteries. 



Of the branches of the common femoral, the deep external pudic 

 might join with the superficial of the internal pudic. Of the deep 

 femoral, the anastomoses of the external circumflex with the gluteal 

 and the sciatic, of the internal circumflex with the sciatic and obturator, 

 and of the superior perforating with the sciatic would all help. 



THE INTERNAL ILIAC ARTERY 



The internal iliac artery descends from the bifurcation of the 

 common trunk, for about i in., to the great sacro-sciatic foramen, 

 where it divides into an anterior and a posterior trunk. 



Relations. In front are the peritoneum and rectum, and the 

 bladder and ureter. Behind are the internal iliac vein, the lumbo- 

 sacral cord, and the side of the sacrum, the anterior division of the 

 artery being continued over the sacral plexus and the pyriformis. 



To the outer side is the brim of the pelvis, the obturator nerve, and 

 the external iliac vessels. Internally is the rectum. 



Hypogastric arteries. In the infant the internal iliac arteries are 

 so large that they seem to represent the divisions of the aorta itself, 

 the external iliacs coming off as mere branches. They give off twigs 

 into the pelvis, and run, but little reduced in size, along the brim of 

 the pelvis and up the side of the bladder to leave the abdomen at the 

 umbilicus, carrying impure blood to the placenta. Within the a,bdo- 

 men they are the hypogastric arteries, but outside they are the arteries 

 of the umbilical cord (v. p. 298). 



