138 VETBRINARY SURGICAL OPERATIONS 



on first sight and before it has been loosened from its sur- 

 roundings. An artery is bluish and roughened, and never 

 presents the longitudinal fibers so characteristic of the nerve 

 trunk. It is also more elastic and lifts from its trough more 

 easily than the nerve trunk. It has not the same substantial 

 attachment to its adjacent structures as the nerve. The dif- 

 ferentiation between nerve and artery, if difficult to the cas- 

 ual operator, is quite easy for the experienced surgeon, from 

 inspection. When there is any doubt, after taking its phys- 

 ical appearance into account a prick of a pin above the co- 

 cainized portion will serve to make the differentiation more 

 certain. 



The length of the incision is not restricted so long as the 

 technique is so directed as to assure primary union of the 

 skin, but when the wound suppurates the smaller the incision 

 the smaller will be the scar. About one-hajf inch is sufficient 

 for the plantar operations, and one and a half inches for the 

 higher and deeper neurotomies. It is possible to elevate the 

 digital and plantar nerves through very small dermal incis- 

 ions, but there is no notable advantage in the method where 

 cleanliness prevails. 



Control of Blood-flow. — The flow of blood in neurotomy 

 is controlled chiefly' for the purpose of facilitating dissection. 

 It is accomplished by the application of a rubber tourniquet 

 above the seat of operation and by bailing the oozing blood 

 from the incision with a sponge or pledget of cotton. In 

 neurotomies above the tarsus or carpus the tourniquet is not 

 applicable, and only the latter method applies, with the occas- 

 ional twisting of a spurting vessel with the forcep. When 

 any of the large vessels are accidentally cut they must be 

 promptly l.igated before the operation is carried into the ad- 

 vanced steps. It is never admissible to arrest such haemor- 

 rhage by compression. With a little effort these vessels can 

 always be isolated and properly ligated, to the decided bene- 

 fit of the healing process, in contra-distinction to the harm- 

 fulness of the wadding or the compressing bandage. 



Suturing the Wound.— The wound is always closely su- 

 tured so as to heal without drainage, with the exception of 

 that of median neurotomy, which will be considered later. 

 In applying the stitches the edges of the wound are lifted 

 consecutively with the dissection forcep and the needle 

 passed through with the needle holder, instead of manipu- 

 lating them with the hands, which at this stage of the opera- 

 tion are liable to have become soiled. The crucial stitch 

 (Fig- 5 8 )> the mattress stitch (Fig. 57) or the simple inter- 



