A New Vascularized Cervical Lymph Node Transplantation Model

Abstract

Vascularized lymph node transfer is of high interest for the treatment of lymphedema. Currently, there are few experimental small animal models of vascularized lymph node transplantation. In this article, our aim was to describe a new vascularized cervical lymph node transplantation model in rats. Ten male Sprague-Dawley rats weighing 200 to 250 g were used in this study. The anatomic features of the neck lymph nodes in rats were explored. Anatomic neck dissections were performed, and lymph node flaps were harvested. The common carotid artery and the jugular vein were used as the vascular pedicles of the lymph node flap. Methylene blue dye was injected into the arterial pedicle. Lymph nodes were identified, and their structure was confirmed by histological evaluation. Laser-assisted indocyanine green angiography was used to confirm perfusion of the lymph node flap. An adequate perfusion was observed in the lymph node flap. The dye disseminated evenly within the lymph nodes, indicating that the flap had a well-established vascular network and an adequate blood supply. Macroscopically, perfusion of 5 to 6 lymph nodes was observed. Histological examination of tissue samples confirmed well-defined lymph nodes. After indocyanine green administration, fluorescence was observed throughout the lymph node flap and within the venous pedicle of the flap. To the best of our knowledge, this is the first report describing vascularized lymph node flap in the head and neck region of a rat. Our lymph node flap preparation technique confirmed the presence of 5 to 6 lymph nodes within the flap. The presented vascularized lymph node flap can be applied to transplantation studies, lymphedema studies, and to studies on immunological mechanism of tolerance and rejection.