Retrograde Parotid Gland Infusion through Stensen's Duct in a Non-Human Primate for Vectored Gene Delivery

This protocol is important because it demonstrates the procedure of retrograde salivary gland infusion in detail. The procedure can be used for a variety of medical reasons, such as vectored immunoprophylaxis or gene therapy. This technique is easy to learn and reproduce.

The authors have managed to perform this procedure successfully on multiple occasions in spite of not being oral surgeons, nor having any such background. After anesthetizing use dental loupes for magnification and identify the parotid papilla or the opening of the Stenson's duct on the posterior cheek adjacent to the upper second molar. Gently dilate the parotid papilla by placing the point of a conical dilator into the center or opening of the papilla and rotate the dilator back and forth for approximately 20 to 30 seconds.

Next, using tweezers hold the marked end of the polyethylene tube attached to the infusate containing syringe at approximately 0.5 centimeters from the distal end and gently insert the tip of the tube into the dilated papilla. Gently advance the tube by small rotating movements to help the tubes slide, followed by readjustment of the tweezers 0.5 centimeters proximal to the previous grip. Repeat this process until the two centimeter mark reaches the parotid papilla.

Next, to seal the parotid papilla and reduce spillage of the infusate back in the oral cavity, apply a cyanoacrylate on the cheek around the papilla and on the inserted tube. Once the cyanoacrylate dries, slowly inject the infusate over five minutes at a rate of 100 microliters per minute. After the infusion is complete, leave the tube in place for at least five minutes, thereby keeping the duct sealed and allowing the infusate to remain in the parotid gland.

Finally, remove the tube with gentle traction and the cyanoacrylate will pull free with the tube. Fluoroscopy using a radio contrast infusion demonstrated branching of the solution through the Stenson's duct and into the parotid gland. Immuno as the chemical analysis of the parotid gland revealed positive staining for EGFP in both the ductal and acinar cells indicating successful transduction and transcription in both cell types.

The main challenge in this procedure is probably introducing the polyethylene tube into the papilla, which should be done very gently and slowly.