576 THE BLOOD-VASCULAR SYSTEM. 



the vessels. The linger being introduced into the wound and the pulsation of the artery felt, 

 the sheath should be opened on the outer side of the vessel to a sufficient extent to allow of the 

 introduction of the ligature, but no farther ; otherwise the nutrition of the coats of the vessel 

 may be interfered with, or muscular branches which arise from the vessel at irregular intervals 

 may be divided. In this part of the operation the long saphenous nerve and the nerve to the 

 Vastus internus, which is in close relation with the sheath, should be avoided. The aneurism 

 needle must be carefully introduced and kept close to the artery, to avoid the femoral vein, 

 which lies behind the vessel in this part of its course. 



To expose the artery in Hunter's canal, an incision should be made through the integument, 

 between three and four inches in length, a finger's breadth internal to the line of the artery, in 

 the middle of the thigh i. e., midway between the groin and the knee. The fascia lata having 

 been divided, and the outer border of the Sartorius muscle exposed, it should be drawn inward. 

 when the strong fascia which is stretched across from the Adductors to the Vastus internus will 

 be exposed, and must be freely divided ; the sheath of the vessels is now seen, and must be 

 opened, and the artery secured by passing the aneurism needle between the vein and artery in 

 the direction from without inward. The femoral vein in this situation lies on the outer side of 

 the artery, the long saphenous nerve, on its anterior and outer side. 



It has been seen that th,e femoral artery occasionally divides into two trunks below the origin 

 of the profunda. If in the operation for tying the femoral two vessels are met with, the surgeon 

 should alternately compress each, in order to ascertain which vessel is connected with the 

 aneurismal tumor or with the bleeding from the wound, and that one only should be tied which 

 controls the pulsation or haemorrhage. If, however, it is necessary to compress both vessels 

 before the circulation in the tumor is controlled, both should be tied, as it would be probable that 

 they became reunited, as in the instances referred to above. 



In wounds of the femoral artery the question of the mode of treatment is of considerable 

 importance. If the wound in the superficial structures is a large one, the injured vessel must 

 be exposed and tied ; but if the wound is a punctured one and the bleeding has ceased, the 

 question will arise whether to cut down upon the- artery or to trust to pressure. Mr. Cripps 1 

 advises that if the wound is in the " upper part of the thigh that is to say, in a position where 

 the femoral artery is comparatively superficial the surgeon may enlarge the opening with a 

 good prospect of finding the wounded vessel without an extensive or prolonged operation. If 

 the wound be in the lower half of the thigh, owing to the greater depth of the artery and the 

 possibility of its being the popliteal that is wounded, the search is rendered a far more severe 

 and hazardous operation, and it should not be undertaken until a thorough trial of pressure has 

 proved ineffectual." 



Great care and attention are necessary for the successful application of pressure. The limb 

 should be carefully bandaged from the foot upward to the wound, which is not covered, and then 

 onward to the groin. The wound is then dusted with iodoform or boracic powder and a conical 

 pad applied over the wound. Rollers the thickness of the index finger are then placed along 

 the course of the vessel above and below the wound, and the whole carefully bandaged to a back 

 splint with a foot-piece. 



Collateral Circulation. When the common femoral is tied the main channels for carrying 

 on the circulation are the anastomoses of the gluteal and circumflex iliac arteries above with the 

 external circumflex below ; of the obturator and sciatic above with the internal circumflex below ; 

 and of the comes nervi ischiadici with the arteries in the ham. 



The principal agents in carrying on the collateral circulation after ligature of the superficial 

 femoral artery are, according to Sir A. Cooper, as follows : 



" The arteria profunda formed the new channel for the blood." "The first artery sent off 

 passed down close to the back of the thigh-bone, and entered the two superior articular branches 

 of the popliteal artery. ' ' 



"The second new large vessel, arising from the profunda at the same part with the former, 

 passed down by the inner side of the Biceps muscle to a branch of the popliteal which was dis- 

 tributed to the Gastrocnemius muscle ; whilst a third artery, dividing into several branches, 

 passed down with the sciatic nerve behind the knee-joint, and some of its branches united them- 

 selves with the inferior articular arteries of the popliteal, with some recurrent branches of those 

 arteries, with arteries passing to the Gastrocnemii, and, lastly, with the origin of the anterior 

 and posterior tibial arteries." 



"It appears, then, that it is those branches of the profunda which accompany the sciatic 

 nerve that are the principal supporters of the new circulation." 



In Porta's work 3 (tab. xii., xiii. ) is a good representation of the collateral circulation after 

 the ligature of the femoral artery. The patient had survived the operation three years. The 

 lower part of the artery is at least as large as the upper ; about two inches of the vessel appear 

 to have been obliterated. The external and internal circumflex arteries are seen anastomosing 

 by a great number of branches with the lower branches of the femoral (muscular and anasto- 

 motica niagna) and with the articular branches of the popliteal. The branches from the 

 external circumflex are extremely large and numerous. One very distinct anastomosis can be 

 traced between this artery on the outside and the anastomotica magna on the inside through the 

 intervention of the superior external articular artery, with which they both anastomose ; and 



1 Heath's Dictionary nf Practical Suryery, vol. i. p. 525. 



* Med.-Chir. Trans., vol. ii. 1811. 3 Alterazioni patolncjiche delle Arlerie. 



