Establishment of submandibular gland allotransplantation model in miniature swine:

Salivary Gland Transplantation as a Promising Approach for Tear Film Restoration in Severe Dry Eye Disease

With increased awareness of dry eye disease (DED), a multitude of therapeutic options have become available. Nevertheless, the treatment of severe DED remains difficult. In a patient whose DED is related to the loss of lacrimal function without severe destruction of the salivary glands, autologous transplantation of the latter as functioning exocrine tissue to rebuild a stable tear film is an attractive idea. All three major and minor salivary glands have been used for such transplantation. Due to the complications associated with and unfavorable prognosis of parotid duct and sublingual gland transplantation, surgeons now prefer to use the submandibular gland (SMG) for such procedures. The transplantation of the SMG not only has a high survival rate, but also improves dry eye symptoms and signs for more than 20 years post-surgery. The regulation of the secretion of the transplanted SMG is critical because the denervated SMG changes its mechanism of secretion. Innovative procedures have been developed to stimulate secretion in order to prevent the obstruction of the Wharton's duct and to decrease secretion when postoperative "epiphora" occurs. Among the minor salivary glands, the transplantation of the labial salivary glands is the most successful in the long-term. The measurement of the flow rates of minor salivary glands and donor-site selection are critical steps before surgery.

Primary Sjogren's syndrome: current and prospective therapies

OBJECTIVE

To summarize data on existing and experimental therapies for primary Sjogren's syndrome (pSS), referring both to sicca syndrome and to other systemic disease manifestations.

METHODS

Relevant English and non-English articles acquired through Medline were reviewed.

RESULTS

pSS usually has a benign clinical course, centered on sicca features and general musculoskeletal manifestations, and is managed symptomatically. However, a subset of patients develops more severe extraglandular disease that warrants close monitoring and aggressive treatment. For dry eyes and mouth, nonpharmacologic measures to preserve secretions, and tear and saliva substitutes, offer some symptomatic relief. Muscarinic agonists and topical cyclosporine yield well-documented improvement in ocular sicca features. Although traditional antirheumatic drugs are used empirically for polyarthritis and other Sjogren's symptoms, their efficacy in pSS overall and as disease-modifying agents is limited. For the potential severe, nonexocrine manifestations complicating pSS, standard high-dose immunosuppression is used. Among the biologic agents already examined in pSS, those targeting tumor necrosis factor (TNF)-alpha failed to demonstrate significant benefit. Nonetheless, rituximab and other B-cell-depleting therapies appear promising.

CONCLUSIONS

Treatment of pSS patients with severe extraglandular disease should differ from that of patients with predominantly sicca features and/or general muscoloskeletal manifestations. pSS treatment is mainly symptomatic, primarily directed against sicca complaints. The traditional anti-rheumatic agents show limited efficacy in the systemic process and use of systemic TNF-alpha inhibitors has been very disappointing. B cell depleting treatments and other newer biologic therapies appear more promising.

Saliva Secretion Stimulated by Grafted Nerve in Submandibular Gland Allograft in Dogs

BACKGROUND

Recent studies have described submandibular gland allografts in animal models; however, the amount of saliva secretion or nervous regeneration in those animals have not been reported. Herein, we investigated saliva secretion from submandibular gland allografts in beagle dogs.

METHODS

Using a vascularized submandibular gland transplantation method, we extracted portions of the submandibular gland including the duct from beagle dogs and placed them into the submental region of age- and weight-matched dogs. Differences in the amount of saliva secretion and histologic appearance were compared based on the existence of chorda tympani branches in the allograft.

RESULTS

At 10 weeks after transplantation, the amount of resting saliva in the group grafted with the nerve was clearly increased, whereas the quantity of that in the group that underwent transplantation without the nerve was quite low. In the former group, responses were demonstrated after taste stimulation and electronic nerve stimulation.

CONCLUSIONS

Our results showed a clear relationship between the presence of a nerve in grafted submandibular glands and saliva secretion.

Submandibular Gland Transfer for Severe Xerophthalmia

OBJECTIVE

To report early clinical experience with a new microvascular reconstructive procedure for patients with severe xerophthalmia.

STUDY DESIGN

Retrospective clinical series.

METHODS

Patients with severe xerophthalmia were referred for treatment after having exhausted all conventional means of treatment. The ipsilateral submandibular gland was transferred to the temporal fossa, as described by Macleod et al., and revascularized using the superficial temporal artery and appropriate vein(s). The submandibular duct was directed to the superolateral fornix so that the saliva produced moistened the eye. Results and complications were reviewed.

RESULTS

Seven microvascular submandibular gland transfer procedures were performed in five patients, ages 6 to 54. The etiology of severe xerophthalmia was Stevens-Johnson syndrome in four and chemical burn in one. Follow-up time was 4 to 20 months. Successful transfer with revascularization was achieved in six of seven (86%) cases. Schirmer's test scores improved from 1.3 pretransfer to 8.1 posttransfer (P = .005). Patients experienced symptomatic relief within 1 month, and the microenvironment of the eye surface improved enough to make them candidates for visual restorative eye surgery. There were no major complications.

CONCLUSIONS

Microvascular submandibular gland transfer is an effective approach for correcting severe xerophthalmia. The procedure should be within the skills of any reconstructive microsurgeon. This procedure offers a unique opportunity for otolaryngologist-head and neck reconstructive surgeons to help restore vision to this unfortunate group of patients.