Surgical anatomy of the vascularized submental lymph node flap: Anatomic study of correlation of submental artery perforators and quantity of submental lymph node

Background: Harvesting the submental flap for vascularized lymph node transfer (VLNT) presents a challenging procedure because of, the topographic variation of the submental artery (SA) and the marginal mandible nerve (MMN) and the limited pedicle length for a free tissue transfer. The aim of this study was to evaluate surgical anatomical landmarks and variations of the submental lymph node flap (SLNF). Methods and Materials: The authors examined the characteristics and landmarks of 18 SLNF in nine fresh cadavers. The diameter, length, and caliber of the SA and its relation to bony anatomic landmarks were measured. In addition, the number of lymph nodes (LNN) was evaluated through dissection and ultrasound. Results: Within the designated SLNF (10 × 5 cm²), the number of LNN was on average 3 ± 0.6, with an average size of 4.5 ± 1.8 mm × 2.9 ± 1.2 mm. Projection of the LNN on the mandible, measured from the gnathion (GT, median-sagittal-plane) toward the gonion (GN, mandibular angle), was at 63.4 ± 5.8 mm (e.g., 65%) of the mandible for the first lymph node (LN), and for the following LNN was at 50.4 ± 7.7 mm (e.g., 52%), 44.0 ± 8.6 mm (e.g., 45%), and 40.50 ± 2.1 mm (e.g., 42%). The MMN consistently crossed the mandible body and the facial artery (FA) from dorso-caudal to ventro-cranial at 72 ± 5.2 mm, e.g., 75% of the mandible's length. Here, the nerve always lay superficial to the FA and was on average 0.96 ± 0.14 mm in diameter. Submental artery was located on average at 64 mm (e.g., 66%) of the mandible, with an average diameter of 1.34 ± 0.2 mm. Conclusion: The submental lymph node flap has a constant vascular supply by the submental artery. Lymph node count is on average three. Lymph nodes are close to the submental artery and its perforators. Marginal mandibular nerve lies superficial to the facial artery and crosses the artery at 75% of the mandible body length (gnathion to gonion = 100%). J. Surg. Oncol. 2017;115:54–59.