Vulnerability of the spinal accessory nerve in the posterior triangle of the neck: a cadaveric study.

Injury to the accessory nerve results in an obvious shoulder droop, loss of shoulder elevation, and pain. Prevention of inadvertent injury to the accessory nerve is critical in neck dissection. No previous study, however, anatomically demonstrates the mechanism of the spinal accessory nerve traction injury. Anatomic determination of the location and course of the spinal accessory nerve may be helpful for a better understanding of the mechanism of the nerve injury. The accessory nerve courses obliquely across the posterior triangle on the surface of the levator scapula muscle and reaches the trapezius. The length of the spinal accessory nerve in the posterior triangle is 34.7+/- 6.3 mm. The nerve passes through the posterior border of the sternocleidomastoid muscle 50.7+/- 12.9 mm below the tip of the mastoid process and reaches the anterior border of the trapezius 49.8 +/- 5.9 mm above the clavicle. It makes a posterior angle of 73.1 degrees +/- 19.4 degrees, on average, relative to the posterior border of the sternocleidomastoid. When the shoulder is pulled down and the head is turned to the opposite direction, the spinal accessory nerve is stretched in the posterior triangle. In the posterior triangle, the nerve is vulnerable, since it is superficial and covered only by skin and subcutaneous fascia. Therefore, extreme caution should be taken with any surgical procedures in the posterior triangle. Traction injury of the spinal accessory nerve in the posterior triangle cannot be ignored.     

Suprascapular nerve entrapment. Diagnosis and treatment

Nine patients were found to have suprascapular nerve entrapment confirmed by electromyographic studies after the diagnosis was suspected. Eight patients who had a surgical release of the suprascapular ligament had good and excellent results. Except in rare cases, a positive electromyogram (EMG) including a delayed nerve conduction (using a coaxial needle) is necessary confirming evidence of the need for surgical treatment. The recommended surgical technique involves detaching the trapezius muscle from the spine of the scapula and opening the space overlying the suprascapular ligament. The trapezius is retracted cephalad while the supraspinatus is retracted caudad. This exposure avoids injury to the spinal accessory nerve and promotes a rapid rehabilitation. Suprascapular nerve entrapment should be suspected and included in the differential diagnosis of ill-defined shoulder pain.     

The modifed Eden-Lange procedure for paralysis of the trapezius muscle

Trapezius muscle paralysis results from injury to the spinal accessory nerve. Impairment in the trapezius muscle function may destabilize the muscle resulting in winged scapula. A 25-year-old university student who was active in sports had complaints of shoulder drop and pain on abduction. He had a three-year history of fall resulting in a scapular fracture for which he received conservative treatment. Physical examination showed asymmetry and drop of the right shoulder. Lateral scapular winging was apparent particularly above 90 degrees of abduction. Electromyography revealed isolated paralysis of the trapezius muscle. The patient underwent reconstruction with the modified Eden-Lange procedure. After a two-year follow-up, asymmetry in the shoulder decreased, there was no pain on active abduction, and the patient returned to active sports and was fully satisfied with the outcome.     

Clinical signs of accessory nerve palsy

BACKGROUND: Injury to the spinal accessory nerve causes paralysis of the trapezius muscle, which is a painful and disabling condition. Many injuries are iatrogenic. Diagnosis is often made after a long delay, suggesting that current clinical signs are inadequate. METHODS: Accessory nerve palsy is known to be a cause of winging of the scapula. Observation of six patients with accessory nerve palsy has shown that winging of the scapula is most prominent when the patient actively externally rotates the shoulder against resistance. RESULTS: This is in contrast to the other causes of winging of the scapula including long thoracic nerve palsy and muscular dystrophy, where the scapula is most prominent on flexion or abduction of the shoulder. CONCLUSION: We propose that the resisted active external rotation test should be regarded as the key clinical sign for accessory nerve palsy.     

Surgical management of trapezius palsy

BACKGROUND: Injury to the spinal accessory nerve in the posterior cervical triangle leads to paralysis of the trapezius muscle. The aim of this study was to determine the indications for nerve repair or reconstructive surgery according to the etiology, the duration of the preoperative delay, and specific patient characteristics. METHODS: Of twenty-seven patients with a trapezius palsy, twenty were treated with neurolysis or surgical repair (direct or with a graft) of the spinal accessory nerve and seven were treated with the Eden-Lange muscle transfer procedure. Lymph node biopsy was the main cause of the nerve injury. The nerve repairs were performed at an average of seven months after the injury, and the reconstructive procedures were done at an average of twenty-eight months. Nerve repair was performed for iatrogenic injuries of the spinal accessory nerve, within twenty months after the onset of symptoms, and in one patient with spontaneous palsy. Reconstructive surgery was performed for cases of trapezius palsy secondary to radical neck dissection, for spontaneous palsies, and after failure of nerve repair or neurolysis. The mean follow-up period was thirty-five months. The functional outcome was assessed clinically on the basis of active shoulder abduction, pain, strength of the trapezius on manual muscle-testing, and level of subjective patient satisfaction. RESULTS: The results were good or excellent in sixteen of the twenty patients treated with nerve repair and in four of the seven patients treated with the Eden-Lange procedure. Poor results were seen in older patients and in patients with a previous radical neck dissection. CONCLUSIONS: Good results can be expected from a repair of the spinal accessory nerve if it is performed within twenty months after the injury, as the nerve is basically a purely motor nerve and the distance from the injury to the motor end plates is short. Muscle transfer should be performed in patients with spontaneous trapezius palsy, when previous nerve surgery has failed, or when the time from the injury to treatment is over twenty months. Treatment is less likely to succeed when the patient is older than fifty years of age or the palsy was due to a radical neck dissection, penetrating injury, or spontaneous palsy.     

Suprascapular nerve release for treatment of shoulder and periscapular pain following intracranial spinal accessory nerve injury

Iatrogenic injury to the spinal accessory nerve is one of the most common causes of trapezius muscle palsy. Dysfunction of this muscle can be a painful and disabling condition because scapular winging may impose traction on the soft tissues of the shoulder region, including the suprascapular nerve. There are few reports regarding therapeutic options for an intracranial injury of the accessory nerve. However, the surgical release of the suprascapular nerve at the level of the scapular notch is a promising alternative approach for treatment of shoulder pain in these cases. The author reports on 3 patients presenting with signs and symptoms of unilateral accessory nerve injury following resection of posterior fossa tumors. A posterior approach was used to release the suprascapular nerve at the level of the scapular notch, transecting the superior transverse scapular ligament. All patients experienced relief of their shoulder and scapular pain following the decompressive surgery. In 1 patient the primary dorsal branch of the C-2 nerve root was transferred to the extracranial segment of the accessory nerve, and in the other 2 patients a tendon transfer (the Eden-Lange procedure) was used. Results from this report show that surgical release of the suprascapular nerve is an effective treatment for shoulder and periscapular pain in patients who have sustained an unrepairable injury to the accessory nerve.     

Successful restoration of the trapezius muscle using pedicle latissimus dorsi. A case report

Reconstruction of the trapezius muscle using a pedicle latissimus dorsi flap was performed in a 27-year-old man with a large synovial sarcoma in his shoulder girdle. Size and location of the tumor required combined resection of surrounding muscles, including the trapezius, levator scapulae, and rhomboid major and minor. Thus, an extensive defect of the suspending muscles of the scapula was created after accomplishing an adequate resection of the tumor. The flap was performed to restore the trapezius functionally because there were no adjacent muscles available. The transferred muscle compensated for loss of the trapezius, thereby recovering excellent shoulder function. Although an opportunity of its application is thought to occur infrequently, the pedicle latissimus dorsi can activate scapular motion successfully in the absence of the levator scapulae. The technique may be extended to salvage failed conventional reconstruction after spinal accessory nerve palsy.     

Long-term results of spinal accessory nerve-facial nerve anastomosis.

A number of methods have been developed to reduce the cosmetic and functional disability resulting from facial nerve loss. It has often been suggested that the major trunk of the spinal accessory nerve should not be sacrificed for providing dynamic facial function because of shoulder disability and pain. A review of Mayo Clinic records has revealed that, between the years of 1975 and 1983, 25 patients underwent spinal accessory nerve-facial nerve anastomosis using the major division (branch to the trapezius muscle) of the spinal accessory nerve. There were 11 males and 14 females, ranging in age from 16 to 60 years (mean 41 years). The interval between facial nerve loss and anastomosis was 1 week to 34 months (mean 4.62 months). The duration of follow-up study ranged from 7 to 15 years (mean 10.8 years). Twenty patients had no complaints or symptoms related to their shoulder or arm at the time of this review and no patient had significant shoulder morbidity. The facial function achieved was "minimal" in five cases, "moderate" in six, and good to excellent in 14. Most patients appeared to benefit significantly from the spinal accessory nerve-facial nerve anastomosis. The morbidity of the procedure seemed quite minimal even in the young and active. The authors continue to believe that the spinal accessory nerve-facial nerve anastomosis, even when using the major trunk of the spinal accessory nerve, is a very useful and beneficial procedure.     

Patient outcome after surgical management of an accessory nerve injury.

OBJECTIVE: This study assessed patient outcome following surgical reconstruction of the accessory nerve after an iatrogenic injury. STUDY DESIGN: A retrospective chart review of 8 patients was performed. RESULTS: There were 3 men and 5 women in the study, and the mean time between injury and nerve graft/repair surgery was 5 months. Four injuries were sustained during a lymph node biopsy. Electromyography revealed a complete accessory nerve injury in all cases. In 6 cases, a nerve graft was required (mean length, 3.6 cm), and in 2 cases, a direct nerve repair was possible. The trapezius muscle was successfully reinnervated in all cases. In total, full shoulder abduction was achieved in 6 cases; in the remaining 2 cases, the patients achieved shoulder abduction to 90 degrees. CONCLUSION: Functional deficit after accessory nerve injury is significant. Nerve graft/repair reconstruction reliably yields a satisfactory result, providing good scapular rotation and thus good shoulder function.     

Reconstruction of spinal accessory nerve after radical neck dissection.

Resection of the spinal accessory nerve in cases of radical neck dissection often causes considerable damage to the function of the shoulder girdle; it leads to limitation of the motion of the upper limb and pain in the shoulder girdle. It seems a sensible compromise to reconstruct the spinal accessory nerve in one-stage operation with radical neck dissection, which can often prevent extensive atrophy of the trapezius muscle, with a resultant improvement in the chance of successful rehabilitation. The technique of the operation is described: after completion of radical neck dissection, in one-stage operation an autogenous nerve transplant from the n. auricularis magnus is sewn onto the central and peripheral stumps of the spinal accessory nerve, which are protected by a "vein-muff" and the fascia of the muscle. After such spinal accessory nerve reconstruction, subjective complaints and objective symptoms were much milder in 6 patients than in the control group, which consisted of 10 patients who underwent a similar operation but without spinal accessory nerve reconstruction.     

Iatrogene Läsion des Nervus accessorius bei der cervicalen Lymphknotenbiopsie

The majority of lesions of the spinal accessory nerve occur as an iatrogenic injury after lymph node biopsy in the posterior cervical triangle (trigonum colli laterale). In most cases the accessory nerve palsy is not recognised immediately after the injury. Therefore surgical repair is often performed too late to regain sufficient function of the paralytic trapezius muscle. Later than 6 months after the injury, reconstruction seems to be hopeless. However, "timely" reconstructions often have poor results. Exact knowledge of anatomy, postoperative check of the trapezius muscle and, if an accessory nerve injury has occurred, early reconstructive procedures (neurolysis, reconstruction of nerve continuity) may on the one hand prevent iatrogenic lesions of the nerve and on the other hand improve the reconstructive result. A series of 6 patients with an injury of the spinal accessory nerve after lymph node biopsy is reported. In 2 cases primary coaptation, in 3 cases interpositional nerve grafting and in 1 case neurotization was performed. Clinical recovery was achieved in 3 of the 6 cases.     

Surgical anatomy of the spinal accessory nerve in the posterior triangle of the neck

OBJECTIVE: The major complication of neck dissection and surgery at the posterior triangle of the neck is severe disability of the shoulder or "shoulder syndrome", which results from spinal accessory nerve injury. Surgical landmarks of the nerve in this area were studied. METHODS: Fifty-six fresh Thai cadavers (112 necks) were dissected to identify the anatomical relationship of the spinal accessory nerve and its commonly used landmarks. RESULTS: The spinal accessory nerve was found within 3.6 cm (mean, 1.43 cm) above Erb's point. The distance between the spinal accessory nerve entering the trapezius muscle and the clavicle was between 2.6 cm and 6.9 cm (mean, 4.5 cm). CONCLUSION: Our data were different from those described in the literature. Reconsideration of these two important landmarks can help to minimize iatrogenic injury of the spinal accessory nerve.     

Reconstruction of the spinal accessory nerve with autograft or neurotube? Two case reports

Injury to the spinal accessory nerve is most commonly iatrogenic, but can be related to cervical trauma or resection of tumor. Of the two most recent publications related to injury of the spinal accessory nerve, one describes transfer of the levator scapulae muscle to restore shoulder function, while the other reports on the results of six surgical repairs, three of which used a sural nerve graft to reconstruct a short neural defect. The present report describes the results obtained in two patients when an iatrogenic injury to the XIth nerve was reconstructed at 3 months after the loss of shoulder function. Denervation of the XIth nerve was confirmed by a first EMG at 6 weeks, and a second one at 12 weeks. At surgery, each XIth nerve was found to have an in-continuity neuroma, most probably related to electrocoagulation. Intraoperative electrical stimulation did not pass the region of nerve injury. In the first patient, the XIth nerve was reconstructed with an autograft from the greater auricular nerve. In the second patient, the XIth nerve was reconstructed with a bioabsorbable conduit, the Neurotube. The patient with the Neurotube reconstruction reached M5 trapezius function by 3 months after surgery, and had no nerve graft donor-site morbidity, while the patient with the autograft reached M4 function by 6 months after reconstruction, and has persistent numbness of the ear lobe. This is the first reported case of a cranial motor nerve being reconstructed with a bioabsorbable conduit.     

Spinal accessory nerve palsy: An unusual complication of rhytidectomy

Rhytidectomy is a safe and effective procedure for rejuvenation of the aging face. Reported complication rates vary between 2.5% and 28%, and with proper management, longterm sequelae are unusual. Injury to the spinal accessory nerve is a rare but potentially debilitating complication of rhytidectomy. Afflicted patients present with dull, constant pain in the shoulder region which can be severe in nature. In addition, there is weakness of shoulder abduction and cosmetic deformity related to trapezius atrophy. Measures for conservative management include analgesics and physical therapy to strengthen the shoulder girdle. Nerve exploration is indicated for cases with documented denervation that do not respond to conservative treatment. A review of the English literature identified two previous case reports of spinal accessory nerve injury sustained during rhytidectomy. In this report, we present two additional cases and review current concepts regarding diagnosis, management, and prevention of this unusual complication of rhytidectomy. © 1994 John Wiley & Sons, Inc.     

Anatomy of the scapulothoracic articulation

Four fresh frozen human cadavers (eight extremities) consisting of the head, neck, thorax, and entire upper extremities were used for dissection of the scapulothoracic articulation. In each specimen, the spinal accessory nerve, all relevant muscle insertions, and bursae were identified and measured. The structures of the scapulothoracic articulation can be divided into superficial, intermediate, and deep layers. The superficial layer consists of the trapezius, latissimus dorsi, and an inconsistent bursa between the inferior angle of the scapula and the latissimus dorsi. The intermediate layer consists of the levator scapulae, rhomboid minor and major, spinal accessory nerve, and scapulotrapezial bursa located between the superomedial scapula and the overlying trapezius. In all specimens, the spinal accessory nerve traveled intimately along the wall of the scapulotrapezial bursa, an average of 2.7 cm lateral to the superomedial angle of the scapula. The deep layer consists of the serratus anterior, subscapularis, and two bursae: one between the serratus and the thorax, the scapulothoracic bursa; and one between the subscapularis and the serratus, the subscapularis bursa.     

Accessory nerve palsy following thoracotomy

A previously unreported cause of 11th cranial nerve palsy is described in a 53-year-old man. Dysfunction of the trapezius branch of the spinal accessory nerve occurred following median sternotomy and was documented by electromyography. This injury resulted in dysfunction of the trapezius muscle with loss of support of the shoulder girdle and pain. The injury may have been due to stretching from sternal retraction or injury secondary to internal jugular venous cannulation.     

Iatrogenic spinal accessory nerve injury in children

Injury to the spinal accessory nerve in the posterior triangle of the neck results in trapezius paralysis and shoulder dysfunction. The most common etiology is iatrogenic and has been reported extensively in adults. We report 3 cases of spinal accessory nerve injury recognized postoperatively in children and discuss the microsurgical treatment, results, and simple strategies to avoid this complication.     

Pathology of the peripheral nervous system

This review deals with papers on important topics in peripheral nerve surgery. Some new diagnostic tools and microsurgical procedures are brought to the attention of neurosurgeons. The first four papers are related to new surgical strategies in treating brachial plexus injury (BPI), particularly root avulsion. Concepts based on experimental studies are applied to clinical practice. Re-establishment of the continuity of interrupted spinal roots or reimplantation of the avulsed spinal roots into the spinal cord are attempted. The authors demonstrate how computed tomography (CT) myelography can be used to plan surgical treatment correctly. The use of reinnervated free-muscle transfer after complete brachial plexus C5-T1 root avulsion is described and critically evaluated. The results obtained after repair of interrupted spinal roots or reimplantation of avulsed spinal roots into the spinal cord are not as clear as described by the authors. Further experimental studies and surgical outcomes are necessary before accepting the efficacy of such surgical procedures in BPI. Reinnervated free-muscle transfer appears to be a promising method for treating such severe lesions. The fifth paper is a case report in which the trapezius branch of the spinal accessory nerve was neurotized with the dorsal branch of the third cervical nerve. This procedure was performed after an injury to the spinal accessory nerve in the neck. The proximal stump of the spinal accessory nerve was available only intracranially. Using this procedure, the risk related to an intracranial approach to the spinal accessory nerve is avoided. A review of one case of primitive neuroectodermal malignant tumor of the median nerve is used to discuss some controversies related to the treatment of malignant tumors involving peripheral nerves.     

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

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-known 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.     

Nerve transfer to deltoid muscle using the nerve to the long head of the triceps,part II: a report of 7 cases

PURPOSE: This study reports the results of nerve transfer to the deltoid muscle using the nerve to the long head of the triceps. METHODS: Seven patients with an average age of 25 years with loss of shoulder abduction secondary to upper brachial plexus injuries had nerve transfer using the nerve to the long head of the triceps to the anterior branch(es) of the axillary nerve through the posterior approach. The spinal accessory nerve was used simultaneously for nerve transfer to the suprascapular nerve. The follow-up period ranged from 18 to 28 months (average, 20 mo). RESULTS: All patients recovered deltoid power against resistance (M4) at the last follow-up evaluation. Useful functional recovery was achieved in all 7 patients; 5 had excellent recoveries and 2 had good results. The average shoulder abduction was 124 degrees. No notable weakness of elbow extension was observed. CONCLUSIONS: This method is a reliable and effective procedure for deltoid reconstruction in brachial plexus injury (upper-arm type) and should be combined with spinal accessory nerve transfer to the suprascapular nerve to obtain good shoulder abduction.