The Thigh. 341 



drawing aside the sartorius, areolar tissue presents itself, 

 and, this being incised, the transversely directed fibres of 

 the aponeurosis, which forms the roof of Hunter's canal, 

 and is especially marked in its lower two-thirds, is recog- 

 nized. The sheath is opened, well to the inner side of the 

 front of the artery, and the needle passed from without 

 inwards, being closely applied to the artery to avoid the 

 femoral vein, which, here, is adherent to the back and 

 outer side of the vessel. The long saphenous nerve which 

 lies in front and to the outer side of the artery, in the 

 canal, can be easily avoided. 



Collateral circulation after ligature of the superficial 

 femoral artery, is carried on, chiefly by means of . ( 1 ) the 

 descending branches from the internal and external cir- 

 cumflex anastomosing with the anastomotica magna and 

 the superior articular branches oi the popliteal; (2) the 

 perforating and terminal branches of the profunda with 

 the articular branches of the popliteal, and (3) branches 

 of the comes nervi ischiadici communicating, on the pop- 

 liteal nerves, with branches from the popliteal and pos- 

 terior tibial arteries. 



Ligation of the Gluteal Artery. This artery is very 

 rarely ligated, but, should it be necessary, an incision is 

 made along the line of the landmarks for the vessel, viz., 

 along a line drawn from the posterior superior spine of 

 the ilium to the posterior superior angle of the great tro- 

 chanter when the thigh is rotated inwards. The centre 

 of the incision should correspond to the exit of the glu- 

 teal, referred to in landmarks for the gluteal region, viz., 

 at the junction of the upper and middle thirds of this line. 

 The gluteus maximus is incised in the direction of the in- 

 cision, which corresponds also to the direction of the fibres 

 of this muscle. The posterior border of the gluteus 

 medius is separated from the upper border of the pyri- 



