Microvascular transplantation of the rat submandibular gland

Xerostomia results from salivary gland irradiation during treatment of head and neck malignancies. In addition to having difficulty with speech and sw allowing, these patients experience loss of taste, dental caries, and chron ic fungal infections. The paired submandibular glands provide 70 percent of the normal salivary flow and are difficult to shield during radiation ther apy. Another sicca condition, xerophthalmia, may result from facial nerve i njury or other medical disorders and results in Pain, corneal ulceration, a nd possible vision loss. Treatment options for xerostomia are limited, and management of xerophthalmia usually focuses on thr eyelids, rather than the fundamental problem of inadequate secretory protection. In this study, a r at model for submandibular gland microvascular transplantation was develope d to assess the feasibility of salivary tissue transfer. Sixteen rats under went submandibular gland transplantation from the neck to the groin. Fourte en of these rats underwent microvascular anastomosis of the vascular pedicl e. Ten glands were assessed for viability at 4 days after transplantation, and four glands were examined after 7, 10, 14, or 21 days. By gross and his tologic examination, 93 percent of transplanted glands showed expected long -term viability after at least 4 postoperative days. Microvascular techniqu es were shown to be applicable to the transplantation of submandibular glan d salivary tissue. This has not previously been shown in a rat model. It is possible that submandibular glands could be transplanted to the eye for tr eatment of xerophthalmia and out of the neck during irradiation of the head and neck, with subsequent replantation after treatment as a means of preve nting permanent xerostomia.