50 TRIFACIAL NEURECTOMY 



rating it from the nerve, protect carefully against injury. 

 With a probe-pointed bistoury or scissors, sever the nerve at 

 the foramen and grasping the distal end dissect away about 

 5 cm. of the trunk and excise. Be very careful to include 

 all branches and especially one or two superior or dorsa' 

 twigs which are directed upward just as they emerge from 

 the foramen. After the hemorrhage has been brought under 

 complete control and all blood clots have been removed, 

 cleanse the wound carefully, disinfect and close with con- 

 tinuous sutures. 



In order to protect this first wound during the operation 

 upon the other side, take the piece of gauze mentioned 

 among the needs for the operation, and folding it several 

 times in a square, place it over the wound and suture it 

 firmly at each corner to the skin. Turn the animal to the 

 opposite side and repeat the operation on the other nerve 

 except the application of the square piece of gauze which 

 is here unnecessary. If circumstances will permit, it is far 

 safer in actual practice to operate first upon only one side, 

 allowing this to heal and then to operate upon the other side. 



As soon as the animal stands, remove the protective piece 

 of gauze from the first wound, disinfect both wounds, 

 and leave undisturbed to heal by primary union. Avoid 

 halter, bridle or other fixtures which might injure the 

 wounds after the operation. 



In some cases the operation may be performed upon the 

 standing animal under local anaesthesia and whenever this 

 is possible it is greatly to be preferred since the hemorrhage 

 is far lessened and the danger from sepsis reduced, but with 

 most afEected animals the standing operation is impractic- 

 able. 



Dangers. The chief danger in the operation is from in- 

 fection, which causes a severe inflammation in the proximal 

 end of the nerve, aggravates the symptoms and causes much 

 suffering. In order to prevent infection the aseptic precau- 



