If a wound is so high up in a patient's thigh that you cannot control bleeding by tying his femoral artery below its profunda branch (which is the main source of his collateral circulation), you may have to tie his external iliac artery instead. Be careful not to injure his external iliac vein and femoral nerve as you do so. This is a difficult procedure, if you are inexperienced.
The external iliac artery arises at the brim of the pelvis from the common iliac artery and runs to the mid inguinal point, where it becomes the femoral artery. The external iliac vein lies medial to it, and the psoas muscle behind it. The femoral nerve lies about a centimetre lateral to it, with the genitofemoral nerve in between them. The peritoneum lies in front of the artery, until the point at which it turns upwards on to the anterior abdominal wall. Below this point, and immediately above the inguinal ligament, the external iliac artery is related from within outwards to: (1) the transversalis muscle, (2) the internal oblique, and (3) the external oblique muscles.
Two branches arise from the external iliac artery : (1) The inferior epigastric artery, which runs upwards into the rectus sheath (23-20). (2) The deep circumflex iliac artery, which runs laterally along the back of the inguinal ligament.
TYING THE EXTERNAL ILIAC ARTERY Put the patient into a moderate Trendelenburg position. Make an incision above and parallel to the middle of his inguinal ligament. Open his inguinal canal and divide the muscular fibres of his internal oblique above his inguinal ligament.
Incise his transversalis fascia, and retract his spermatic cord upwards and medially. Gently raise his peritoneum and you will see his external iliac artery and vein. As you do so, try not to cut his inferior epigastric artery and its vein.
Separate the artery carefully from the vein, pass an aneurysm needle round it, tie it with 1 silk or linen, and don't divide it.
Fig. 3-9 EXPOSING THE FEMORAL ARTERY is one of the more useful of the arterial exposures described here, because you will need it in an above-knee amputation, and you may need it in a penetrating wound of the thigh. Adapted from ''Farquharson's Textbook of Operative Surgery', edited by RF Rintoul. Churchill Livingstone, with kind permission.