Surgical Anatomy of Spinal Accessory Nerve: Is Trapezius Functional Deficit Inevitable after Division of the Nerve?

2001 ◽  
Vol 26 (2) ◽  
pp. 137-141 ◽  
Author(s):  
Z. H. DAILIANA ◽  
H. MEHDIAN ◽  
A. GILBERT

The course of spinal accessory nerve in the posterior triangle, the innervation of the sternocleidomastoid and trapezius muscles and the contributions from the cervical plexus were studied in 20 cadaveric dissections. The nerve was most vulnerable to iatrogenic injuries after leaving the sternocleidomastoid. Direct innervation of trapezius by cervical plexus branches was noted in five dissections, whereas connections between the cervical plexus and the spinal accessory nerve were observed in 19 dissections. These were usually under the sternocleidomastoid (proximal to the level of division of the nerve in nerve transfer procedures). Although the contribution from the cervical plexus to trapezius innervation is considered minimal, trapezius function can be protected in neurotization procedures by transecting the spinal accessory nerve distal to its branches to the upper position of trapezius.

2005 ◽  
Vol 28 (3) ◽  
pp. 171-173 ◽  
Author(s):  
Atchara Aramrattana ◽  
Kanchana Harnsiriwattanagit ◽  
Pichit Sittitrai

2007 ◽  
Vol 20 (8) ◽  
pp. 899-904 ◽  
Author(s):  
Torpon Vathana ◽  
Mikko Larsen ◽  
Godard C.W. de Ruiter ◽  
Allen T. Bishop ◽  
Robert J. Spinner ◽  
...  

2019 ◽  
Vol 31 (1) ◽  
pp. 133-138 ◽  
Author(s):  
Johannes A. Mayer ◽  
Laura A. Hruby ◽  
Stefan Salminger ◽  
Gerd Bodner ◽  
Oskar C. Aszmann

OBJECTIVESpinal accessory nerve palsy is frequently caused by iatrogenic damage during neck surgery in the posterior triangle of the neck. Due to late presentation, treatment regularly necessitates nerve grafts, which often results in a poor outcome of trapezius function due to long regeneration distances. Here, the authors report a distal nerve transfer using fascicles of the upper trunk related to axillary nerve function for reinnervation of the trapezius muscle.METHODSFive cases are presented in which accessory nerve lesions were reconstructed using selective fascicular nerve transfers from the upper trunk of the brachial plexus. Outcomes were assessed at 20 ± 6 months (mean ± SD) after surgery, and active range of motion and pain levels using the visual analog scale were documented.RESULTSAll 5 patients regained good to excellent trapezius function (3 patients had grade M5, 2 patients had grade M4). The mean active range of motion in shoulder abduction improved from 55° ± 18° before to 151° ± 37° after nerve reconstruction. In all patients, unrestricted shoulder arm movement was restored with loss of scapular winging when abducting the arm. Average pain levels decreased from 6.8 to 0.8 on the visual analog scale and subsided in 4 of 5 patients.CONCLUSIONSRestoration of spinal accessory nerve function with selective fascicle transfers related to axillary nerve function from the upper trunk of the brachial plexus is a good and intuitive option for patients who do not qualify for primary nerve repair or present with a spontaneous idiopathic palsy. This concept circumvents the problem of long regeneration distances with direct nerve repair and has the advantage of cognitive synergy to the target function of shoulder movement.


2010 ◽  
Vol 12 (1) ◽  
pp. 22-24 ◽  
Author(s):  
R. Shane Tubbs ◽  
William Stetler ◽  
Robert G. Louis ◽  
Ankmalika A. Gupta ◽  
Marios Loukas ◽  
...  

Object The spinal accessory nerve (SAN) has been reported to have a distinctly coiled appearance in its course through the posterior cervical triangle of the neck. As this is unusual compared with other peripheral nerves including the cranial nerves, the present histological analysis was performed to further elucidate the reason for this anatomy with potential application in nerve injury and repair. Methods Ten adult cadavers underwent dissection of the neck. The SAN was harvested proximally and within the posterior cervical triangle. For comparison with other cranial nerves within the neck, the cervical vagus and hypoglossal nerves were also harvested. All nerves underwent histological analysis. Additionally, 2 human fetuses (11 and 20 weeks' gestation) underwent examination of the SAN in the posterior cervical triangle, and 3 randomly selected specimens were submitted for electromicroscopy. Results All SANs were found to have a straight gross configuration proximal to the posterior triangle and a coiled appearance within this geometrical area. Histologically, no differences were identified for the SAN in these 2 locations (that is, proximal to and within the posterior cervical triangle). The histology of the SAN both with routine analysis and electron microscopy was similar in both regions and to nerves used as controls (for example, vagus and hypoglossal nerves). Interestingly, both fetal specimens were found to have coiled SANs in the posterior cervical triangle. Conclusions Based on this study, it appears that the tortuous course of the SAN in the posterior triangle arises from functional as opposed to structural forces. It is hoped that this analysis will provide some insight into the nature behind the morphology observed in the SAN within the posterior cervical triangle and aid in future investigations regarding its injury. Moreover, such a coiled nature of this nerve may assist the neurosurgeon in identifying it during, for example, neurotization procedures.


2009 ◽  
Vol 141 (5) ◽  
pp. 639-644 ◽  
Author(s):  
Sang Hyuk Lee ◽  
Jong Kyu Lee ◽  
Sung Min Jin ◽  
Jin Hwan Kim ◽  
Il Seok Park ◽  
...  

Objective: This study was conducted to identify anatomical variations of the spinal accessory nerve (SAN) in the upper neck, the landmark of the anterior and inferior border of level IIb, and to evaluate the nerve's effect on the border and the number of lymph nodes (LNs) in level IIb. Study Design and Setting: Case series with planned data collection. Subjects and Methods: A total of 181 neck dissections (NDs) were prospectively enrolled in this study. The relation between the SAN and adjacent structures (internal jugular vein [IJV], sternocleidomastoid muscle [SCM], cervical plexus) and the number of LNs in level IIb was investigated. Results: The SAN crossed the IJV ventrally in 72 cases (39.8%) and dorsally in 104 cases (57.4%), and passed through the IJV in five cases (2.8%). The SAN ran along the inner surface of the SCM and sent branches to the SCM without penetration of the muscle in 83 cases (45.9%), whereas in 98 cases (54.1%) the nerve sent branches to the SCM by penetration. Cervical plexus contribution to the SAN was seen from C2 in 96 cases (53.1%), C2 and C3 in 69 cases (38.1%), and C3 in 16 cases (8.8%). The mean number of LNs of level IIa and level IIb was 6.5 and 8.2 in cases in which the SAN crossed the IJV ventrally, and 6.8 and 5.4 in dorsally crossing cases. LNs included in the neck level IIb in ventrally crossing SAN cases were significantly larger than the dorsally crossing cases ( P < 0.05). Conclusions: Our results may help to minimize the incidence of injuring the SAN in the upper neck during ND. Neck level IIb would contain more LNs if the course of the nerve leans toward the ventral side.


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