Microvascular anastomosis of the human lacrimal gland: a concept study towards transplantation of the human lacrimal gland

INTRODUCTION: Severe aqueous tear deficiency is caused by primary or secondary main lacrimal gland insufficiency. The transplantation of a human lacrimal gland could become a potential treatment option to provide physiological tears with optimal properties. To this end, we performed an ex vivo study to develop a surgical strategy that would ensure a vascular supply for a lacrimal gland transplant using microvascular techniques. MATERIAL AND METHODS: Five cadaver heads were used to perform a lateral orbitotomy in order to identify the vascular pedicle and the lacrimal gland itself. The principal feasibility and the time of the required surgical steps for an intraorbital microvascular re-anastomosis of the human lacrimal gland were documented. Patency and potential leakage of the anastomosis were tested with hematoxylin intraoperatively. Postoperatively, routine histological, as well as scanning electron microscopy (SEM) of the gland and vascular anastomosis, were performed. RESULTS: The vascular pedicle of all five glands could be isolated over a minimum stretch of at least 1 cm, severed, and successfully reanastmosed microsurgically. Time for arterial anatomization (n = 4) was 23 ± 7 min and 22 ± 3 min for the vein (p = 0.62). The total time for the entire microvascular anastomosis was 46 ± 9 min. All anastomosis were patent upon testing. SEM revealed well-aligned edges of the anastomosis with tight sutures in place. CONCLUSION: Our study demonstrates as proof of principle the feasibility of intraorbital microvascular re-anastomosis of a human lacrimal gland within the presumed window of ischemia of this tissue. This should encourage orbital surgeons to attempt lacrimal gland transplantation in humans in vivo.