550 



OPERATIONS ON THE NERVOUS SYSTEM. 



in the middle, and the nerve behind — the veia being on a plane 

 somewhat more superficial than the artery, which is a little deej)er. 

 Consequently the operation may be performed at any one of four 

 points, and on either side of the leg. 



These are, first, above the fetlock, on the plantar nerve proper ; 

 second, below the fetlock, on the posterior branch ; third, below 

 the fetlock, also on the anterior branch ; and fourth, according to 

 Nocard, above the fetlock, on the anterior branch. The first or 

 second of these locations is more often selected for the operation^ 

 and forms either the high or loio process. 



For each of these operations there is a point of selection. In 

 the high process this is immediately above the fetlock, where the 

 nerve is most superficial and most easily exposed, on the outside 

 border, and a little in front of the perforans tendon. In the low 

 method it is below the fetlock, in the middle of that part of the 

 coronet region where a depression is felt between the tendon and 

 the first phalanx. 



The question of preference between the high and low opera- 

 tions has been made the subject of much discussion, and it re- 

 mains still unsolved. With many the high operation is that which 

 yields the best results; others hold that the object especially con- 

 templated in any given case must determine the point as the oc- 

 casion presents itself. It is only just to say, however, that the ma- 

 jority of practitioners prefer the high operation ; not only because 

 it is easier to perform, but also because it is more likely to be 

 successful. 



Personally, we believe that the high operation, with some 

 few exceptional cases, is that which will prove almost generally 

 beneficial. 



The instruments necessary are, a pair of scissors, a convex 

 bistoiuy or scalpel (we prefer the latter), a narrow, straight bis- 

 toury, two dissecting forceps, a pair of blunt tenaculums, with 

 an elastic band (Fig. 464), an aneurism tenaculum (Fig. 465), 

 needles, thread and sponges. Those who are familiar with the 

 operation highly commend a new instrument, the neurotome (Fig. 

 466), which has been invented to take the place of the straight 

 bistoury. 



Neurotomy is a simple operation, but a very paiaful one, and 

 it is necessary, therefore, to have the animal well secured from the 

 commencement of his struggles, which may endanger both himself 



