The Great Auricular Nerve as a Nerve Graft Donor: An Anatomical and Clinical Study of the Maximum Harvestable Length and Branches.

BACKGROUND: For immediate facial nerve reconstruction during head and neck tumor resection, a great auricular nerve (GAN) graft can be potentially harvested in the same surgical field during tumor resection. However, it is often avoided because a GAN graft is only approximately 5 cm long without any branches, and a sural nerve graft is recommended for larger defects. We investigated the length of the GAN that can be harvested in 18 patients, along with the evaluation of postoperative facial nerve palsy. METHODS: We retrospectively analyzed 18 cases of immediate facial nerve reconstruction using the GAN from 2018 to 2023 at our hospital. In most cases, we traced the GAN to the back surface of the sternocleidomastoid and harvested the nerve graft immediately before the loops of the cervical nerve plexus or bifurcation into the phrenic nerve. This tracing method allowed the collection of a longer nerve graft with more branches. RESULTS: The mean length of the harvested GAN was 8.16 cm (95% confidence interval 7.42-8.89 cm), with the longest graft being 10.5 cm. The GAN grafts had an average of 1.83 branches and were 1.76-2.23 mm in diameter. Three patients had two peripheral transected edges of the facial nerve, each of which was sutured with a branch of the GAN graft. Three patients had five-six peripheral edges and required additional nerve grafts, such as the sural nerve. Postoperative facial nerve palsy was grade III or IV by House-Brackmann and FNGS 2.0 in all cases. CONCLUSIONS: For immediate facial nerve reconstruction, the GAN can be harvested in a length of at least 8 cm and few branches by sufficient dissection of the back surface of the sternocleidomastoid muscle, including its branches and other sensory nerves, with few complications.