Transplantation of the Autologous Submandibular Gland to the Lacrimal Basin in Rats

Abstract

Purpose: In this study, we designed an animal experiment in which we transferred a part of the autologous submandibular gland without performing a microvascular anastomosis. We studied histological changes and functional effects in the transfer glands. Method: Thirty male adult Sprague-Dawley rats were divided into three groups. In each animal of the three groups, the right eye was the control eye and the left eye the experimental eye. Surgical removal of the extraorbital lacrimal gland from the control eyes was performed to create a condition simulating keratoconjunctivitis sicca. In the experimental eyes of group 1, in addition to the removal of the extraorbital lacrimal gland, a part of the autologous submandibular gland was transferred to the orbit and fixed to the intraorbital lacrimal gland. In the experimental eyes of group 2, in addition to the removal of the extraorbital lacrimal gland, an aseptic silicon rubber was transferred to the orbit and fixed to the intraorbital lacrimal gland. In the experimental eyes of group 3, there was no removal of the extraorbital lacrimal gland but instead a sham operation was performed. The histological changes and innervation pattern in the transferred submandibular gland of group 1 were observed. Tear secretion of each group was measured to study the functional effect. Results: Three months after the transplantation, the transferred submandibular glands were similar to the unoperated submandibular glands both in histology and innervation pattern. In group 1, the tear secretion in the experimental eyes was significantly greater than that of the control eyes at 2 and 3 months following transfer. In group 2, no significant difference was noted between the experimental eyes and control eyes. In group 3, the difference in tear secretion between the experimental eyes and control eyes was significant. Conclusion: The result of this study revealed that although the procedure did not involve vascular anastomosis, the transfer gland showed a normal histological appearance and good reinnervation, even 3 months after the transfer. These transferred submandibular glands continued to secrete tears. This secretion continued to increase up until the end of the experimental period.

Effect of Subconjunctival Lacrimal Gland Transplantation in a Rabbit Dry Eye Model

“…Nemet et al 12 performed subconjunctival transplantation of the main lacrimal gland tissue from neonatal mice to adult mice and confirmed the survival of the lacrimal gland tissue as an allograft, but could not demonstrate an increase in tear volume. In contrast, Liu et al 13 transplanted the salivary gland to a subconjunctival site in rats and found an increase in the tear volume, although it was unclear whether this effect could persist in the long term. When the salivary gland was transplanted to a subconjunctival site in humans, however, there was no change in the tear volume, and lymphocytic infiltration was observed.…”

“…11 Based on such anatomical similarity, attempts have been made to transplant the main lacrimal gland or salivary gland tissue to a subconjunctival site. [12][13][14] Nevertheless, the outcome of transplantation has often been unsatisfactory because an allograft or heterograft was used.…”

Submandibular Gland Transfer for Severe Xerophthalmia

“…This procedure would be much easier to perform if revascularization were not required. Liu et al 14 have studied this question in a rat model. After 3 months, the nonvascularized transferred SMGs appeared to have normal histology and reinnervation, and the eyes were not dry compared with controls.…”

A novel treatment for keratitis sicca (Dry eye): Anatomical feasibility study

“…For example, implantation of gold weights on the upper lid have been used to treat patients with inability to fully close the eye after injury to the facial nerve or Bell's palsy (Tan et al, ). In animals, Liu et al () induced this condition by removing the lacrimal gland. The authors then transplanted submandibular tissue without a vascular pedicle and found that the submandibular tissue began to secrete tears and maintain a lubricated cornea.…”