Septum-based cervical lymph-node free flap in rat: a new model

Background: A limited number of lymph node flap models are available in rats, and none of them include a skin paddle. The aim of this study was to describe a new cervical lymph node-adipo-cutaneous flap model in the rat for future experimental studies. Material and Methods: Fifteen Wistar rats were used. In four, neck anatomy was investigated with special focus on cervical lymph nodes. In eleven rats, a lymph node flap with a skin paddle of 1.5 0.5 cm centered along the surface projection of the innominate septum was harvested and transferred to the inguinal region. The rats were followed-up for 7 d. At 30- d postoperatively, the lymphatic flow restoration with the recipient limb lymphatics was assessed with methylene blue, and histology was performed on excised flaps. Results: According to the anatomic findings, the flap was based on an innominate septum which was a well-defined adipofascial structure containing glandular vessels to the surrounding tissues and located between submandibular-sublingual glandular complex and parotid gland. Flap’s microvascular and lymph node anatomy (two to three lymph nodes) was constant. Donor-site morbidity was minimal, and all flaps survived. At 30- d postoperatively, the restoration of the lymphatic flow with the recipient limb lymphatics was observed, and histology revealed viable lymph nodes. Conclusions: The constant anatomy, the possibility to include a skin paddle and the minimal donor-site morbidity, make this flap a safe, reliable, and versatile lymph node flap supermicrosurgical model for autologous transplant in the rat for future experimental studies.