Intraductal injection as an effective drug delivery route in the management of salivary gland diseases

Drug Therapeutics Delivery to the Salivary Glands: Intraglandular and Intraductal Injections

Salivary gland hypofunction and xerostomia following pathological conditions like Sjogren's syndrome or head and neck radiotherapy usually lead to tremendous impairment of oral health, speech, and swallowing. The use of systemic drugs to alleviate the symptoms of these conditions has been associated with various adverse effects. Techniques of local drug delivery to the salivary gland have grown enormously to address this problem properly. The techniques include intraglandular and intraductal injections. In this chapter, we will provide a review of the literature for both techniques while incorporating our lab experience in using them.

The sialodynamic test: A preliminary porcine head study

Objectives

To provide a concept of measuring pressure changes under constant fluid infusion for the diagnosis of sialolithiasis, termed the sialodynamic test, in a porcine head model.

Methods

Using a porcine head model, a constant infusion of water into the submandibular gland of the two groups over 30 s was performed and the outlet pressure was measured. Metal beads were inserted into the salivary duct for obstruction simulation after the normal submandibular gland sialodynamic measurements were completed. Statistical analyses were performed to evaluate the differences between the measured individuals and the experimental group (n = 3).

Results

The results showed no significant difference between individuals in the control group, but intergroup variation was noted in the simulated sialolithiasis group. The volume-dependent linear increase in pressure was exacerbated in the simulated sialolithiasis group compared with the control.

Conclusion

This study indicated that evaluating the relationship between pressure and volume changes can help to determine whether stones are present in the submandibular gland. The sialodynamic test might serve as a potential diagnostic method for salivary diseases.

Office-based salivary gland ductal irrigation in patients with chronic sialoadenitis: A preliminary study

BACKGROUND/PURPOSE

To evaluate the therapeutic responsiveness of office-based salivary gland ductal irrigation in patients with chronic sialoadenitis.

METHODS

Between August 2017 and April 2019, 55 patients comprising the following three disease groups were enrolled: Sjogren's syndrome: 39 patients; postradiotherapy sialoadenitis: ten patients; and post-RAI sialoadenitis: six patients. Quantitative salivary scintigraphy was recorded, and a formulated questionnaire including the Summated Xerostomia Inventory was utilized to assess acute/chronic symptoms. All patients received at least three serial salivary gland ductal irrigations with a one-month interval in our outpatient department.

RESULTS

The general response rates for each disease groups are as follows: Sjogren's syndrome: 61.5% (24/39); postradiotherapy: 60% (6/10); and post-RAI: 83.3% (5/6). Among the patients with Sjogren's syndrome, the parotid scintigraphic T_min showed a significant positive correlation with the responsiveness of salivary irrigation (P = 0.046), whereas the treatment tended to be irresponsive in patients who previously took medicine for their related discomfort (P = 0.009). In the postradiotherapy and post-RAI groups, no significant factors were found to be associated with the responsiveness of irrigation.

CONCLUSION

Simple salivary ductal irrigation without complex equipment can be performed as an outpatient procedure to alleviate glandular swelling or xerostomia in patients with Sjogren's syndrome, postradiotherapy sialoadenitis or post-RAI sialoadenitis, and it can be considered an alternative management approach for patients refractory to conventional strategies.

The Efficacy and Safety of Submandibular Transcatheter Perfusion Anesthesia in Submandibular Gland Surgery

The present study aims to evaluate the feasibility, safety, and effects of the combined use of submandibular transcatheter perfusion with lingual nerve block and subcutaneous infiltration for anesthetic purposes during submandibular gland surgery. A total of 38 patients with benign tumors, who had undergone resection by submandibular gland surgery were randomly divided into 2 groups. Patients in group A were administered with submandibular anesthesia through catheter perfusion, lingual nerve block, and subcutaneous infiltration anesthesia. Patients in the group B were only treated with lingual nerve block and subcutaneous infiltration anesthesia. The submandibular gland surgery was performed within 5 minutes following anesthesia administration, after which the numerical rating scale (NRS) was evaluated before surgery, during skin incision (T1), during the pulling process of the submandibular gland (T2), during the removal of the submandibular gland (T3), and at 2, 6, 12, and 24 hours post-surgery. The dosage of analgesic drugs was also measured after surgery. The findings revealed no significant difference in NRS before surgery, at T1, 6, 12, and 24 hours after surgery (P > 0.01) while NRS was much lower in group A patients as observed at T2, T3, and 2 hours after surgery when compared with group B (P < 0.01). The combined application of submandibular transcatheter perfusion with lingual nerve block and subcutaneous infiltration can be used as an effective anesthetic method during submandibular gland surgery.

Intraductal Salivary Gland Infusion With Botulinum Toxin

Background

Administration of botulinum toxin through intraductal salivary infusion may decrease the risks of percutaneous needle injection and improve delivery to permeate the entire gland parenchyma.

Methods

The safety of intraductal salivary gland infusion was tested with prospective evaluation of two patients using interviews, clinical examination, and pressure measurement during infusion. Retrospective chart review of two subsequently treated patients assessed treatment of a parotid-cutaneous fistula and sialorrhea.

Results

No complications were identified in the safety study. Pressure changes during infusion supported the concept of botulinum neurotoxin delivery to permeate the gland. Patient-assessed success was subjectively reported as a reduction in the parotid-cutaneous output "by 95%" and the sialorrhea "by 90%" at 2-week follow-up.

Conclusions

The intraductal route of botulinum toxin delivery to salivary glands was without complication and was effective in two patients treated therapeutically. Pressure measurements during infusion may be helpful to direct treatment.

Level of Evidence

4.