Sialendoscopy of Salivary Glands Affected by Sjögren Syndrome: A Randomized Controlled Pilot Study

PURPOSE

Sialendoscopy of the major salivary glands could alleviate the oral symptoms of Sjögren syndrome (SS) and restore salivary function. The aim of this pilot study was to evaluate the effect of sialendoscopy of the major salivary glands on salivary flow, saliva composition, and mouthfeel in patients with SS and to collect data for sample size analysis for a larger clinical trial.

MATERIALS AND METHODS

Twenty patients diagnosed with SS were randomly assigned to a nonintervention control group or a sialendoscopy group. Unstimulated whole saliva flow, stimulated whole saliva flow, Clinical Oral Dryness Score, Xerostomia Inventory score, and EULAR Sjögren's Syndrome Patient Reported Index score were obtained 1 week before (T0), 1 week after (T2), and 8 weeks after (T3) sialendoscopy. Unstimulated whole saliva was analyzed for amylase concentration, activity, and mucin 5B concentration. Amylase and mucin 5B output were calculated.

RESULTS

In the sialendoscopy group, unstimulated and stimulated whole saliva flows were numerically higher at T2 and T3 compared with T0. Xerostomia Inventory score was significantly lower in the sialendoscopy group at T2 compared with T0 (P = .03). Unstimulated and stimulated whole saliva flows were higher in the sialendoscopy group compared with the control group at T2 and T3 (not meaningful). Significant differences were found between groups for the EULAR Sjögren's Syndrome Patient Reported Index score at T2 (P = .03) and T3 (P = .001). Xerostomia Inventory score and Clinical Oral Dryness Score in the sialendoscopy group were lower compared with the control group at T2 (P = .02) and at T3 (P = .04), indicating less oral dryness.

CONCLUSION

This pilot study indicates a positive effect of sialendoscopy on some parameters, but it cannot yet be concluded that it has a positive effect on salivary flow in patients with SS. These preliminary results need to be verified in a randomized controlled trial with a larger sample and longer follow-up period.

Sialendoscopy for Patients with Radioiodine-Induced Sialadenitis and Xerostomia

BACKGROUND

We examined outcomes in patients treated for radioactive iodine-induced sialadenitis (RAIS) and xerostomia with sialendoscopy.

METHODS

Data was prospectively collected for all patients undergoing sialendoscopy for RAIS from a single institution. Interventional details and intraoperative findings were recorded. Qualitative data were obtained through patient examination, telephone interviews, and use of a standard quality of life questionnaire, Xerostomia Questionnaire. Quantitative data were obtained from patients who underwent sialometry.

RESULTS

Twenty-six patients (24 women and 2 men; median age, 43 years; age range, 19-57 years) underwent interventional sialendoscopy after conservative management of symptoms proved unsuccessful. Sialadenitis was present in 25 patients and xerostomia in 22 patients. Mucus plugging in the duct of the gland was the most common finding (22 patients) followed by stenosis (18 patients), inflammation (eight patients), and erythema (eight patients). Median follow-up time was 23.4±12.1 months. Sixteen patients (64%) reported complete resolution; seven (28%), partial resolution; one (4%), no change in symptoms; and one (4%), regression in RAIS-related symptoms. Patients subjectively noted the following regarding their xerostomia symptoms: seven (31.8%) had complete resolution; 10 (45.5%), partial resolution; four (18.2%), no change; and one (4.5%), regression. Statistical analysis of the available sialometry data revealed a statistically significant difference in saliva production at 6 months following sialendoscopy for unstimulated saliva production (p=0.028).

CONCLUSION

Sialendoscopy is an effective treatment option for the management of RAIS and xerostomia refractory to conservative therapy and medical management. Patients in our cohort report durable improvement in symptoms after intervention.

Transplantation of vascularized submandibular gland in dogs

PURPOSE

Presently, treatments for xerostomia only target symptoms, as an active therapy method has not been established. Herein, we discuss the possibility of using a submandibular gland allograft technique for the disease.

MATERIALS AND METHODS

Using a vascularized submandibular gland transplantation method, we extracted portions of the submandibular gland, including the duct and chorda tympani branches, from beagle dogs and placed them into the submental region of age- and weight-matched dogs. We then measured the amount of saliva secretion and examined the grafted glands histologically.

RESULTS

Sufficient quantities of saliva were secreted from the grafted glands with pilocarpine treatment. Histologic findings showed that the acinar cells in the grafted and untreated contralateral glands had some atrophy, as compared with the normal glands; however, periodic acid Schiff staining showed that they produced saliva.

CONCLUSIONS

Transplantation of vascularized submandibular glands into dogs was successful and may become a novel treatment strategy for patients with xerostomia.

Anatomic study of submandibular gland transfer in an attempt to prevent postradiation xerostomia

Xerostomia is the most common negative sequela after radiotherapy for head and neck cancer and results from destruction of normal salivary gland tissue by radiation. We hypothesized that transferring a single submandibular gland outside the radiation field to the submental region may preserve its function, thus preventing xerostomia and its consequences. This anatomic study was designed to evaluate different methods of submandibular gland transfer to the submental region. Eight submandibular glands were dissected in four fresh human cadavers. The anatomy and blood supply of the region were documented. Each gland was transferred to the submental region by either free microvascular transfer or based on retrograde flow through the distal facial vessels. Both methods of transfer resulted in complete relocation of the submandibular gland into the submental region.

A feasibility study of salivary gland autograft transplantation for xerostomia

BACKGROUND

Radiation-induced xerostomia is a frequent sequela in patients treated for cancer of the head and neck. One strategy to treat xerostomia would be to relocate portions of salivary tissue to adjacent submucosal sites that lie outside the radiation portals such as the anterior oral vestibule. It is not known whether salivary tissue transplanted as an autogenous free graft can survive, function adequately, and not produce mucoceles.

METHODS

Salivary gland tissue from the parotid and submandibular glands of the Syrian hamster were transplanted into the submucosal layer of the cheek pouch. After 3 months of observation, looking at graft size, graft extrusion, ulceration, infection, and mucocele formation, the graft sites were harvested. The specimens then underwent pathologic analysis by hematoxylin and eosin staining, as well as immunohistochemical methods to determine positivity for cytokeratin, smooth muscle actin (SMA), and amylase.

RESULTS

Histologic analysis of tissue harvested from Syrian hamsters grafted into the cheek pouch demonstrated intact, viable, organized salivary gland tissue. Eighty percent of the animals in the submandibular group and 63% of the animals in the parotid group had at least 1 graft with viable salivary tissue without undue complications.

CONCLUSIONS

Salivary gland tissue can be transplanted successfully as free autogenous grafts in the Syrian hamster model. Further studies are needed to determine whether the grafts will subsequently become functional and whether growth can be biologically stimulated. This approach may be a useful strategy to protect salivary gland tissue in patients undergoing radiotherapy for head and neck cancer.

Salivary gland transplantation: a canine model

Impaired salivary function with resultant severe dryness of the mouth, or xerostomia, may occur in association with a variety of systemic disorders or therapies. No adequate treatment exists for this debilitating condition, which impedes normal oral function, in particular alimentation and phonation. This study explores the feasibility of salivary gland autotransplantation, using a canine model. A salivary gland with its duct and surrounding blood vessels still attached was excised and reimplanted in the dog's thigh by anastomosing the graft's blood vessels to the femoral artery and vein. The duct was sutured to an artificial orifice cut in the thigh's skin, from which the saliva was collected. Salivary secretion was induced by a single intravenous bolus of pilocarpine (5 mg). Preoperative (normal) salivation was measured by collecting saliva from the gland in situ. Periodic functional studies showed normal saliva production during the first month after grafting, after which the salivary flow was reduced by 35% over the next 2 months. This reduction was interpreted as a sign of disuse atrophy resulting from the lack of autonomic innervation. To overcome this impediment, oral pilocarpine (5 mg/day) was administered to the recipient dog, after which normal levels of saliva were excreted through the graft during the 3-month follow-up period. The quality of the graft saliva was assessed by its protein and electrolyte levels, which showed close to normal values.

Transplantation of immortalized, nontumorigenic parotid acinar cells into the allogeneic rat parotid gland and oral submucosa

The recent establishment of an immortalized clonal cell line of rat parotid acinar cells (2RSG) by transfecting isoproterenol-stimulated parotid cells with a plasmid vector, pSV3neo which carries the large T-antigen gene from SV40 virus, afforded the opportunity to develop a model for parotid acinar cell transplantation. Single cell suspensions of 2RSG cells labeled with a fluorescent tracer, DiI, were injected into the parotid gland or oral submucosa of allogeneic adult rats. The grafted cells survived and were functionally viable for at least 30 days. Histological sections revealed no evidence of infiltration of leukocytes or lymphocytes. Grafted cells did not form tumors. Results suggest that allogeneic parotid acinar cell transplantation is a feasible technique in the animal model.

Xerostomia. A treatment feasibility study in dogs

An acute study was performed in dogs to test the feasibility of using another bodily fluid in place of saliva in patients with xerostomia. Chyle was routed from the thoracic duct to the oral cavity via a vein graft using the external jugular vein. While technically challenging, the vein conduit worked well in delivering chyle to the oral cavity.