LIGATION OF THE PAROTID DUCT. 49 



a sharp scalpel lay it free for a distance of from i to 2 cm. 

 on the glandular side of the fistulous opening. If the 

 fistula has its location on the side of the cheek, cast the 

 horse and shave and disinfect the region on the inferior 

 maxilla where the arterj-, vein and parotid duct turn around 

 its inferior border. When the operator glides his finger 

 over the vascular region from before backward there is felt 

 a resistant cord, the external maxillary artery about 3 mm, 

 in diameter, pulsating in the living animal. Between this 

 and the oral border of the masseter muscle make an incision 

 about 4 cm. long parallel with the artery through the skin 

 and skin muscle. This incision is more readily made by 

 gathering up a fold of skin about 2 cm. high and cutting 

 through it. Pick up the loose connective tissue with a pair 

 of forceps and excise it. Immediately behind the external 

 maxillary artery, a, Figs, I and II, Plate IX, is the ex- 

 ternal maxillary vein, v, and behind this and immediately 

 on the border of the masseter muscle lies the parotid duct, 

 st. In case of salivary calculi which cannot be removed 

 through the mouth and cystic dilation of the parotid duct, 

 make the cutaneous incision at the affected point, open the 

 canal, and after the removal of the calculus, etc., close the 

 duct wound by means of intestinal sutures in such a way 

 that the external surfaces of the lips of the wound in the 

 wall of the duct are brought in contact, or ligate the duct 

 on the proximal side of the point of operation. lyigation is 

 accomplished by passing a strong silk thread behind the 

 duct by means of a curved aneurism needle carrying the 

 ligature around it and tying with a surgeon's knot. The 

 parotid duct can also be previously split and an internal 

 wound made at the point of ligation. Close the skin 

 wound by means of a continuous sjature and cover the 

 operative surface with iodoform collodion or with wound 

 gelatine. 



