Minor salivary gland transplantation

Minor oral salivary glands exist in large numbers in the labial, buccal and palatal mucosa, and account for approximately half of the baseline secretion of saliva. They can be transplanted together with the overlying mucosa as a complex graft to the posterior lamella of the eyelids to increase ocular surface lubrication and reduce discomfort in dry eyes.

The surgical methods and the results of this technique in 17 patients are described. All patients had been retractive to medical treatment. The recipient bed over the lower or upper lid retractors and a donor tissue of lower labial mucosa with its submucosal minor salivary glands of approximately 2.5 x 2 cm were prepared by means of a surgical knife or Ellman Surgitron high-frequency/low-temperature radiosurgical device. The graft was cut in two strips of approximately 2.5 x 1 cm size and sutured to the recipient site with interrupted or running sutures. The labial wound was left open for second intention healing.

All grafts remained viable and vascularised within 1 week. Vascularisation of the graft was associated with an improvement of symptoms and increased ocular surface lubrication. Complications included temporary labial hypaesthesia, partial necrosis of the graft (n = 1), herpes simplex virus keratitis (n = 1) and epiphora (n = 1). Viable glandular tissue was found in specimens taken 18 and 36 months postoperatively. Other reported complications include lid malpositioning such as ptosis and entropium.

Transplantation of minor salivary glands is a promising new treatment option for severe dry eyes. The procedure is simple with minimal surgical risks. These grafts remain viable in over 90% and seem to be capable of sustaining a basal secretion for up to 36 months. Since experience with this technique is still very limited, prospective controlled studies have to be performed to establish the long-term survival of the glands and to characterise the salivary tear film and its impact on the ocular surface.