628 THE ARTERIES. 



Surgical Anatomy. Any of these three vessels may require ligaturing for a wound or for 

 aneurism, which is generally traumatic, and the operation may be performed by an incision, 

 three or four inches long, in the direction of the fibres of the Gluteus maximus muscle, the 

 middle of the cut corresponding to the point indicating their respective positions. 



The External Iliac Artery (Fig. 372). 



The external iliac artery is larger in the adult than the internal iliac, and 

 passes obliquely downward and outward along the inner border of the Psoas 

 muscle, from the bifurcation of the common iliac to Poupart's ligament, where it 

 enters the thigh and becomes the femoral artery. 



Relations. In front, with the peritoneum, subperitoneal areolar tissue, the 

 intestines, ileum on right side, sigmoid flexure on left, and a tHin layer of fascia 

 derived from the iliac fascia, which surrounds the artery and vein, At its 

 origin it is occasionally crossed by the ureter. The spermatic vessels descend for 

 some distance upon it near its termination, and it is crossed in this situation by 

 the genital branch of the genito-crural nerve and the circumflex iliac vein ; the 

 vas deferens curves down along its inner side. Behind, it is in relation with the 

 external iliac vein, which, at Poupart's ligament, lies at its inner side. Exter- 

 nally, it rests against the Psoas muscle, from which it is separated by the iliac 

 fascia. The artery rests upon this muscle, near Poupart's ligament, similarly 

 separated by the fascia. Numerous lymphatic vessels and glands are found lying 

 on the front and inner side of the vessel. 



PLAN OF THE RELATIONS OF THE EXTERNAL ILIAC ARTERY. 



In front. 



Peritoneum, intestines, and fascia. 

 Near f Spermatic vessels. 

 Poupart's < Genito-crural nerve (genital branch). 

 Ligament. ( Circumflex iliac vein. 



Lymphatic vessels and glands. 



Outer aide. / \ Inner side. 



Psoas magnus. ( iiiac External iliac vein and vas deferens 



Iliac fascia. / at femoral arch. 



Behind. 



External iliac vein. 

 Psoas magnus. 

 Iliac fascia. 



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

 been already given (see page 619). 



Surgical 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 great stream of blood in the internal iliac, and near its lower 

 end, which should also be avoided, on account of the proximity of the epigastric and circumflex 

 iliac vessels. One of the chief points in the performance of the operation is to secure the ves- 

 sel without injury to the peritoneum. The patient having been placed in the recumbent posi- 

 tion, 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 running upward and outward, 

 parallel to Poupart's ligament, to a point 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, or, if the 

 lower part of the artery is to be reached, the surgeon may adopt the plan advocated by Sir 

 Astley Cooper, by making an incision close to Poupart's ligament from about half an inch out- 

 side 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 aponeurosis of the external 

 oblique, is less likely to be followed by a ventral hernia, but there is danger of wounding the 

 epigastric artery. 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 peri- 

 toneum 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, 



