508 



ARTERIES. 



The point of division is subject to great variety. In two-thirds of a large number of cases, 

 it was between the last lumbar vertebra and the upper border of the sacrum ; being above that 

 point in one case out of eight, and below it in one case out of six. The left common iliac 

 artery divides lower down more frequently than the right. 



The relative length, also, of the two common iliac arteries varies. The right common iliac 

 was longest in sixty-three cases ; the left, in fifty-two ; whilst they were both equal in fifty-three. 

 The length of the arteries varied in five-sevenths of the cases examined, from an inch and a 

 half to three inches ; in about half of the remaining cases, they artery was longer ; and in the 

 other half, shorter ; the minimum length being less than half an inch, the maximum four and a 

 half inches. In one instance, the right common iliac was found wanting, the external and in- 

 ternal iliacs arising directly from the aorta. 



Surgical Anatomy. The application of a ligature to the common iliac artery maybe required 

 on account of aneurism or hemorrhage, implicating the external or internal iliacs, or on account 

 of secondary hemorrhage after amputation of the thigh high up. It has been seen that the 

 origin of this vessel corresponds to the left side of the umbilicus on a level with a line drawn 

 from the highest point of one iliac crest to the opposite one, and its course to a line extending 

 from the left side of the umbilicus downwards towards the middle of Poupart's ligament. The 

 line of incision required in the first steps of an operation for securing this vessel, would ma- 

 terially depend upon the nature of the disease. If the surgeon select the iliac region, a curved 

 incision, about five inches in length, may be made, commencing on the left side of the umbilicus, 

 carried outwards towards the anterior superior iliac spine, and then along the upper border of 

 Poupart's ligament, as far as its middle. But if the aneurismal tumor should extend high up 



Fig. 294. Arteries of the Pelvis. 



in the abdomen, along the external iliac, it is better to select the side of the abdomen, approach- 

 ing the artery from above, by making an incision from four to five inches in length, from about 

 two inches above and to the left of the umbilicus, carried outwards in a curved direction towards 



