SALIVARY FISTULA. 331 



(5.) SALIVARY FISTULA. 



Wounds of the salivary glands and their ducts often fail to heal, 

 because the continual flow of saliva pushes aside the granulations 

 and hinders closure. The gland epithelium finally unites with that 

 of the outer skin, and through the opening so formed saliva flows 

 continuously (salivary fistula). A distinction must be made between 

 fistula of a salivary gland and that of a salivary duct. The latter 

 occurs most frequently in Stenson's duct. Although the general 

 condition of the animal is only slightly affected, much saliva escapes 

 during eating and mats the hair of the cheek, finally producing a 

 blemish. Fistula? of salivary glands heal more easily than those 

 of salivary ducts, — sometimes, indeed, without treatment of any kind. 



Treatment aims at closing the external opening. This may be 

 done in fistula of the gland by cauterising with nitric acid, silver 

 nitrate, concentrated carbolic acid, or the actual cautery. A scab 

 is thus formed, which cheeks the outflow of saliva, allows the formation 

 of granulations, and promotes cicatrisation. These methods some- 

 times fail at first, and require to be repeated. The draw-purse suture 

 may prove useful. 



The treatment of fistula of the salivary duct is more difficult. 

 Before recovery can take place, it is necessary to provide for the 

 passage of saliva into the mouth. Where stricture of the duct occurs, 

 as it often does, at a point between the fistula and the natural 

 opening, this must be remedied. Lindenberg recommends passing 

 a strong probe, and then attempting to reclose the walls of the fistula 

 by caustic or the cautery. The resulting inflammatory swelling may 

 close the wound, but healing will be more assured if a stitch be 

 inserted. The purse-string stitch is the best. With a strongly 

 curved needle a thread is passed through the skin around the opening 

 of the fistula, and the margins thus brought together. Where the 

 natural opening into the mouth cannot be renewed, an artificial 

 conduit must be provided. Stockfleth recommends exposing the 

 duct behind the fistula, and piercing the cheek in an oblique direction 

 with a trocar. The free portion of the salivary duct is introduced 

 into this opening, and made fast with a suture. Lafosse and Hering 

 passed a tape through the cheek by means of a trocar, and fastened 

 the ends together at the commissure of the lips. After the thread 

 has remained in position for a week or long enough to establish an 

 artificial opening into the mouth, it is removed, and the external 

 wound is then closed with a suture. Should this procedure be in- 

 applicable, or not attended with success, destruction of the function 



