THE INJECTION of various dyes has long been used as an adjunct to excision of lesions such as pilonidal sinuses and thyroglossal duct cysts. The usefulness has been somewhat variable, particularly where spillage of the dye stains adjacent tissues and sometimes confuses rather than assists the operation. Forrest and Robinson1,2 described the use of methylene blue injected into the parotid duct as a technical adjunct to operations for removal of tumors of the parotid gland. They reported that the dye stained the normal gland but not the tumor and that spillage did not occur. The present report concerns a further trial of this method.
At the time of operation, after endotracheal intubation, the duct is visualized, dilated, and cannulated with a polyethylene tube (PE 90). The catheter is threaded in 1.5 cm and anchored to the buccal mucosa with a silk suture. The end of the catheter with