THE FEMORAL ARTERY. 



825 



Anterior crural nerve 



Crural branch of 



genito-crural 



ner\e 



arising from the femoral. This circumstance hkewise interferes with the firmness and 

 security of the clot formation after ligature, [c) The fact that ligature of the 

 common femoral cuts off the chief blood-supply to the lower limb also militates 

 against its selection and leads to the choice of the superficial femoral whenever pos- 

 sible, so as to permit the profunda and its branches to maintain a sufficient vascular 

 current. The incision should be begun on the abdomen a little above Poupart's 

 ligament, midway between the anterior superior spine and the symphysis pubis, and 

 e.xtend downward to about two inches below the ligament in the line of the vessel — 

 vide supra. The structures to be avoided in approaching the artery are the glands 

 and veins that lie in the fat over the cribriform fascia, the superficial epigastric artery 

 and, when the sheath is exposed, the crural branch of the genito-crural ner\^e lying 

 upon it near its outer side. The vein is in close contact with the inner side of the 

 artery. The needle should be passed from within outward. 



The collateral circulation will be carried on from above the ligature by {a) the 

 internal pudic (from the internal iliac); (b) the gluteal and sciatic (from the same 

 vessel); {c) the deep cir- 

 cumflex iliac, from the Fig. 730. 

 external iliac ; (fl')theob- / — -^ 

 turator, and (^) the comes 

 nervi ischiadici, anasto- 

 mosing respectively with 

 {a) the superficial and 

 deep external pudic : (^) 

 the circumflex and per- 

 forating arteries ; {c) the 

 external circumflex ; {d) 

 the internal circumflex ; 

 and {c) the perforating, all 

 from either the common, 

 superficial, or deep fem- 

 oral. 



2. At the apex of 

 Scarpa's triangle an inci- 

 sion with its centre at the 

 apex of the triangle is 

 made on the line of the 

 vessel, the thigh being ab- 

 ducted and rotated out- 

 ward, the hip a little 

 flexed, the knee well 

 flexed, and the leg resting 

 on its outer surface. Be- 

 fore reaching the deep 

 fascia, the long saphenous 

 vein or the external super- 

 ficial femoral vein, may be 



met with and should be avoided. After opening the deep fascia the fibres of the 

 inner edge of the sartorius should be exposed, and may be recognized by their oblique 

 course. That muscle should be displaced outward, the vascular groove containing 

 the vessel and some fatty areolar tissue identified, and the sheath exposed. The 

 internal cutaneous branch of the anterior crural nerve in front, and the nerve to the 

 vastus internus and the long saphenous nerve externally, should be avoided, and the 

 sheath opened. The needle should be passed from without inward to avoid the vein, 

 which here lies behind and to the outer side of the artery. 



3. To reach the vessel in Hunter's canal, the limb being in the position above 

 described, an incision is made on the line of the vessel extending from the apex of the 

 triangle to about three inches above the internal condyle. The long saphenous vein 

 should be avoided. The deep fascia is opened, and the outer edge of the sartorius 

 identified. The only structure that could be mistaken for it is the vastus internus, 



Femoral artery 

 Femoral vein 



Pectineus 



muscle 



Adductor longus 

 muscle 



— ; — Internal saphe- 

 i nous vein 



Superficial dissection of Scarpa's triangle, showing 

 relations of femoral vessels. 



