DIVISION II. 

 SUEGICAL ANATOMY. 



I. SURGICAL ANATOMY OF THE ARTERIES. 



IN the description of the several blood-vessels, the points bearing on 

 operative surgery have been indicated in detail. The leading facts to be 

 attended to by the surgeon in the operation of placing a ligature on the 

 chief arterial trunks will be now collectively considered.* 



SURGICAL ANATOMY OF THE COMMON CAROTID ARTERY. 



The common carotid artery does not furnish any branch, save in very 

 rare instances. In a practical or surgical point of view, the branches arising 

 sometimes close to its upper end may be disregarded, so that a ligature can 

 be applied to any part of the vessel, except immediately at its commence- 

 ment or termination. When the case is such as to allow a choice, the point 

 which combines the most favourable circumstances for the operation, is 

 opposite the lower end of the larynx. Here a large space would, in ordi- 

 nary cases, intervene between the ligature and the ends of the vessel ; and 

 at the same time this part is free from the difficulties offered by the muscles 

 lower down, and by the superior thyroid veins, if the artery be secured near 

 its bifurcation. But it has been shown (p. 345) that the carotid artery 

 occasionally bifurcates below the usual position opposite the lower margin 

 of the larynx, and even, however rarely, lower than this. In such cases, 

 should the artery be laid bare at the point of division, it would be best to 

 tie the two parts separately, close to their origin, in preference to tying the 

 common trunk near its end. If, in consequence of very early division of 

 the common carotid or its entire absence (cases which, however, are of ex- 

 tremely rare occurrence), two arteries (the external and internal carotids) 

 should happen to come into view in the operation supposed, the most judi- 

 cious course would doubtless be to place the ligature on that artery, which, 

 upon trial, as by pressure, should prove to be connected with the disease. 



In performing the operation, the direction of the vessel and the inner 

 margin of the stern o-mastoid muscle are the surgeon's guides for the line of 

 incision! 1 . Before dividing the integument it is well to ascertain whether the 

 anterior jugular vein be in the line of incision. Should the operation be per- 

 formed at the lower part of the neck, some fibres of the muscles will require to 

 be cut across in order to lay the artery bare with facility ; and the necessity 

 for this step increases in approaching towards the clavicle. After the super- 



* The plates referred to in this section are those of Richard Quain " On the Arteries." 



