514 OPERATIONS ON THE CIRCULATORY SYSTEM. 



be obviated, seeing that it merely requii'es careful attention to 

 the execution of the few details which constitute the act of vene- 

 section. But when it has taken j^lace, the simplest and most ob- 

 vious thing to do is, if possible, to remove the air from the vessel 

 in which it has intruded. The means of effecting this consists ia 

 reopening the closed vein, and permitting the blood to resume 

 its flow. The loss of three or four pounds of blood additional 

 is usually sufficient to insure the escape of all the air. Gourdon 

 recommends, in addition, showering with cold water, stimulating 

 frictions, and even, if the case seems to require it, artificial 

 respiration. 



ARTERIOTOMY. 



Bleeding from an artery is so termed to distinguish it from 

 phlebotomy. It is not commonly used in practice, being princi- 

 pally resoi-ted to as a means of local depletion, and is performed 

 only on some of the most suj^erficial of the vessels. In fact, there 

 are but three of these eligible by their position to the operation. 

 These are the transveral of the face, the 2)oste7'ior auricnlar, and 

 the middle caudal. 



The 7nodus operandi differs but httle from that of phlebot- 

 omy, except that there is usually no need of the apphcation of ar- 

 tificial means to swell then- bulk or increase then* rotundit}', their 

 position, and theu' distinct and characteristic pulsation, so readily 

 detected, sufficiently revealing their location and course. In open- 

 ing arteries the fleam is seldom used, the lancet or a pointed bis- 

 toury being a much more eligible instrument. The incision of the 

 vessel is made across its course instead of longitudinally, as ia 

 phlebotomy, and the flow of blood must be arrested by means of 

 pressure with compresses or bandages. 



(a) Bleeding at the Transve?-sal of the Face. — Though the 

 position of this artery is nearly correspondent in all animals, it is 

 principally with soUpeds that it is chosen for blood-letting. It is 

 situated below the temporo-maxillary articulation, and crossing 

 the direction of the fibres of the masseter muscle, where it is cov- 

 ered only by a fine skin, it is opened at the same level with the 

 place where phlebotomy is usually performed. Some operators 

 prefer casting the animal, others the standing position. 



The appearance of the vessel is that of a small, round pulsa- 

 ting cord, and, as before stated, it is incised, not as the veins and 



