A technique for preservation of spinal accessory nerve function in radical neck dissection

Abstract

A new technique is described that preserves trapezius muscle function in radical neck surgery while cutting that part of the spinal accessory nerve which courses through the sternocleidomastoid muscle. The technique takes advantage of the little-know fact that, in humans, the trapezius muscle has dual innervation. The C2-3-4 motor root is joined to the distal portion of the spinal accessory nerve to give motor function to the trapezius muscle. This procedure will save shoulder mobility in the majority of patients who undergo radical neck dissection. The technique is accomplished rapidly with the use of the gastrointestinal stapler in the scalene fat pad.

Intradural anastomoses between the accessory nerve and the posterior roots of cervical nerves: Their clinical significance

“…Furthermore, it may run to the trapezius muscle by way of the spinal cervical nerve. The accessory motor fiber in the cervical nerve may also join the accessory nerve at anastomotic sites in the posterior neck triangle, considering the previous report describing that the C2-3-4 motor root was joined to the spinal accessory nerve distal to the exit from the sternocleidomastoid muscle (Weitz et al, 1982). Conversely, the possibility that the sensory fiber from the cervical posterior root may join the accessory nerve and reach the spinal cord by way of the spinal rootlet of accessory nerve, as suggested in the anastomosis between the accessory nerve and the C-1 posterior root (Ouaknine and Nathan, 1973;Schneider et al, 1996), can not be ruled out.…”

“…The "shoulder syndrome" appears in patients after the standard radical neck dissection due to the paralysis of the trapezius muscle caused by sacrificing the accessory nerve. It has been reported, however, that not all patients suffered from the shoulder syndrome after surgery (Weitz et al, 1982). This phenomenon has been explained as due to the innervation of the trapezius muscle by cervical nerves, independent of the spinal accessory nerve (Soo et al, 1986;Stacey et al, 1995Stacey et al, , 1996.…”

Intraoperative Electromyography for Identification of the Trapezius Muscle Innervation: Clinical Proof of a New Anatomical Concept

“…[5][6][7][8] As we have shown in our recent works, 9,10 this is, at least in part, due to a few traditional ideas on the topographical anatomy of the SAN that are simply wrong, as well as to a broad variety of purely hypothetical and confusing theories on the trapezius muscle innervation. [11][12][13][14] We showed previously that the, functionally, the most important descending part of the trapezius muscle is innervated by a small cranial branch of the SAN 9,10 although this morphological finding had not yet been proven clinically. Therefore, the aim of the present study was to reveal the clinical importance of this small cranial branch of the SAN by means of intraoperative electromyography.…”

Innervation of the trapezius muscle: A study in patients undergoing neck dissections

“…Trapezius function was reported as well preserved in all patients, but there was no mention on how assessment of trapezius function was done. 13 We have described in detail the anatomy of the accessory nerve and its cervical distributions in the neck in cadavers.14 In an attempt to study further the question of the innervation of the trapezius, we studied clinically and electromyographically patients undergoing radical or modified neck dissections.…”