Study on clinical anatomy of the accessory nerve,the great auricular nerve and the transverse nerve of neck in neck levelⅡ-Ⅳ / 中国耳鼻咽喉头颈外科

ABSTRACT

OBJECTIVE To study the anatomicallandmarks of the accessory nerve (AN) , the great auricular nerve (GAN)and the transverse nerve of neck (TN) in neck level Ⅱ-Ⅳ and provide a reliable surgical basis for treatment of functional neck dissection in neck level Ⅱ-Ⅳ. METHODS The courses of the AN, GAN and TN were studied in 42 patients (56 sides) who underwent lateral neck dissection. Meanwhile, the correlations among the three nerves above and their surrounding structures were observed. RESULTS After emerging from the inferior border of the posterior belly of digastric muscle, the AN descends obliquely downward and backward before the transverse process along with the sternocleidomastoid branch of occipital artery to the upper part of the deep surface of the sternomastoid muscle. The distance from the mastoid process to the point where AN enters the sternocleidomastoid muscle is (4.93?0.75) cm. The point where AN emerges from sternocleidomastoid muscle (point A) located above the point where the GAN exits the sternocleidomastoid muscle (point B). The distance between the two points is (1.04?0.59) cm while the distance from point A to the middle point of clavicle (point C) is (8.09?0.65) cm. The GAN leaves the cervical plexus at the posterior border of the sternocleidomastoid muscle and run anteriorly between the lateral surface of this muscle and the deep surface of platysma. It is (6.37?0.73) cm long from point B to point D where the GAN send out posterior aurem branches, auricular lobule branches and anterior auricular branches. The distance from point B to point C is (7.67?1.00) cm. Most of GANand external jugular vein run nearly in parallel and the distance between them is (1.02?0.61) cm. The point where the TN emerges from the posterior border of the sternocleidomastoid muscle is below point B. Then the TN which is below the external jugular vein runs almost horizontally over the surface of the sternocleidomastoid muscle to sector branches in the lateral neck and part of its branches are distributed in the lateral neck after going across the anterior jugular vein. The point where the TN gives off branches is multivariate. There is no significant difference between the data get from left and right neck (P