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.     

后入路副神经移位至肩胛上神经的应用解剖

目的 对斜方肌内的神经支配进行解剖学观察,为寻找副神经移位到肩胛上神经的最佳移位点和移位方式提供解剖依据.方法 选用成人尸体标本10具20侧.观察副神经在斜方肌内的行径及分支.并取不同水平副神经、肩胛上神经横断面制病理切片,计数各神经断面的神经纤维数,进行比较.结果 副神经在锁骨上2～3 cm进入斜方肌内,在肩胛冈中点前上方3～4 cm处,有来自颈丛的交通支加入后形成终末支.副神经的神经纤维计数:入斜方肌处(A点)为(1245±46)条,颈丛的交通支汇入前(B点)为(830±36)条,汇入后(C点)为(1074±38)条.结论 (1)副神经在与颈丛交通支合干后H-G段内的各断点,是副神经的最佳移位点.(2)后进路副神经移位术不影响斜方肌上部神经支配,充分利用了颈丛交通支,且缩短了神经再生距离,值得推广.     

Transfer of the accessory nerve to the suprascapular nerve in brachial plexus reconstruction

PURPOSE: Transfer of the accessory nerve to the suprascapular nerve is a common procedure, performed to reestablish shoulder motion in patients with brachial plexus palsy. We propose dissecting both nerves via a distal oblique supraclavicular incision, which can be prolonged up to the scapular notch. The results of the transfer to the suprascapular nerve are compared with those of the combined repair of the suprascapular and axillary nerves. METHODS: Thirty men between the ages of 18 and 37 years with brachial plexus trauma had reparative surgery within 3 to 10 months of their injuries. In partial injuries with a normal triceps, a triceps motor branch transfer to the axillary nerve was performed. The suprascapular and accessory nerves were dissected via an oblique incision, extending from the point at which the plexus crosses the clavicle to the anterior border of the trapezius muscle. In 10 patients with fractures or dislocations of the clavicle, the trapezius muscle was partially elevated to expose the suprascapular nerve at the suprascapular notch. RESULTS: In all cases, transfer of the accessory to the suprascapular nerve was performed without the need for nerve grafts. A double lesion of the suprascapular nerve was identified in 1 patient with clavicular dislocation. In those with total palsy, the average improvement in range of abduction was 45 degrees , but none of the patients with total palsy recovered any active external rotation. Patients with upper-type injury recovered an average of 105 degrees of abduction and external rotation. If only patients with C5-C6 injuries were considered, the range of abduction and external rotation increased to 122 degrees and 118 degrees , respectively. CONCLUSIONS: Use of the accessory nerve for transfer to the suprascapular nerve ensured adequate return of shoulder function, especially when combined with a triceps motor branch transfer to the axillary nerve. The supraclavicular exposure proposed here for the suprascapular and accessory nerves is advantageous and can be extended easily to explore the suprascapular nerve at the scapular notch.     

The spinal accessory nerve plexus, the trapezius muscle, and shoulder stabilization after radical neck cancer surgery.

A clinical and anatomic study of the spinal accessory, the eleventh cranial nerve, and trapezius muscle function of patients who had radical neck cancer surgery was conducted. This study was done not only to document the indispensibility of the trapezius muscle to shoulder-girdle stability, but also to clarify the role of the eleventh cranial nerve in the variable motor and sensory changes occurring after the loss of this muscle. Seventeen male patients, 49-69 years of age, (average of 60 years of age) undergoing a total of 23 radical neck dissections were examined for upper extremity function, particularly in regard to the trapezius muscle, and for subjective signs of pain. The eleventh nerve, usually regarded as the sole motor innervation to the trapezius, was cut in 17 instances because of tumor involvement. Dissection of four fresh and 30 preserved adult cadavers helped to reconcile the motor and sensory differences in patients who had undergone loss of the eleventh nerve. The dissections and clinical observations corroborate that the trapezius is a key part of a "muscle continuum" that stabilizes the shoulder. Variations in origins and insertions of the trapezius may influence its function in different individuals. As regards the spinal accessory nerve, it is concluded that varying motor and sensory connections form a plexus with the eleventh nerve, accounting, in part, for the variations in motor innervation and function of the trapezius, as well as for a variable spectrum of sensory changes when the eleventh nerve is cut. For this reason, it is suggested that the term "spinal accessory nerve plexus" be used to refer to the eleventh nerve when it is considered in the context of radical neck cancer surgery.     

颈7神经根后股与副神经移位吻合重建斜方肌功能

目的探讨一种根治性颈淋巴清扫术（radical neck dissection，RND）中采用神经移位吻合改善术后肩功能的方法。方法1999年3月～2001年2月，10例需行RND的患者，行RND时保留远颅端至斜方肌前缘的副神经，长度〉3cm，待RND完成后，解削分离出C7神经，并将其后股切断，长度3～5cm，在无张力下行两神经端端吻合。患者在术前和术后1、6及12个月行临床的斜方肌功能客观评价及肌电检测。结果经c，神经根后股与副神经移位吻合后，各部肌电恢复率1、6及12个月分别为上部9．8％、68．9％、73．5％；中部4．7％、73．6％、69．4％；下部6．2％、70．5％、70．3％；7例患者上臂外展超过90。，上肢平均最大外展角度超过95。，肌萎缩较轻，均为1～2级，肩外展受限2级7例．3级3例。结论RND中采用C7神经根后股与副神经移位吻合能较好地重建斜方肌功能。供、受区位于同一术区内，仅有一个吻合口，减少手术创伤。C7神经根后股的切断对手臂运动及感觉功能无影响。     

Repair of peripheral nerve defect with direct gradual lengthening of the proximal nerve stump in rats.

We investigated the effect of direct gradual lengthening on the proximal nerve stump and subsequent nerve regeneration in rats. A 10-mm-long nerve segment was resected from the sciatic nerve of each rat. The proximal nerve stump was directly lengthened at a rate of 1 mm/day using an original external nerve distraction device. Experiment I: After distraction periods of 10, 15, and 20 days, the length of each nerve was evaluated, and the lengthened nerve stump was also examined by immunohistochemical analysis. Experiment II: After a distraction period of 20 days, both nerve stumps were refreshed and direct end-to-end neurorrhaphy was performed. For control, 10-mm nerve grafting was immediately performed after nerve resection. Nerve regeneration was evaluated electrophysiologically and histologically 7, 9, and 15 weeks after nerve resection in both groups. The whole proximal nerve stump, including the endoneurium and the axon, could be lengthened in proportion to the distraction period. There were no significant differences in motor nerve conduction velocity and tetanic muscle contraction force between both groups. Histologically, the total number of myelinated fibers was significantly greater in the nerve lengthening group than in the autografting group. This study demonstrated that the whole proximal nerve stump including the endoneurium and the axon could be lengthened by direct gradual distraction, and that this method might have potential application in the repair of peripheral nerve defects.     

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.     

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.     

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.     

C4副神经移位重建斜方肌功能的实验研究

目的探讨以C4神经前支主干作为动力神经移位修复副神经重建大鼠斜方肌功能的可行性,为临床用于副神经缺损的动力性修复提供理论依据。方法取36只成年雄性SD大鼠,体重200～250 g;随机分为实验组与对照组(n=18)。实验组左侧行C4副神经移位重建术,对照组左侧行副神经切除术;两组右侧不做任何处理,作为正常对照。术后1、2、3个月实验组行复合肌肉动作电位(compound muscle action potential,CMAP)及肌肉功能检测,计算潜伏期延迟率、最大波幅恢复率及肌张力恢复率;取两组斜方肌行HE染色,计算肌细胞截面积恢复率;取实验组神经吻合口远端神经行甲苯胺蓝染色,计算吻合口远端有髓神经纤维恢复率。并于术后1、3个月取实验组斜方肌及神经行透射电镜观察。结果随时间延长,实验组斜方肌CMAP最大波幅逐渐增加,潜伏期缩短,肌张力逐步恢复;神经吻合口远端有髓纤维逐渐增加。至术后3个月肩、背斜方肌CMAP最大波幅恢复率为63.61%±9.29%、73.13%±11.85%,潜伏期延迟率为130.45%±37.27%、112.62%±19.57%,肌张力恢复率为77.27%±13.64%、82.47%±22.94%,有髓纤维通过率为82.55%±5.00%。随神经支配恢复,实验组肌细胞截面积亦逐渐增大,且各时间点与对照组比较差异均有统计学意义(P<0.05)。术后1个月时斜方肌肌节排列紊乱,3个月时逐步趋于整齐。结论 C4副神经移位重建术可有效重建大鼠斜方肌的运动功能。     

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.     

Innervation of the trapezius muscle by the intra-operative measurement of motor action potentials

Although the surgical anatomy of the spinal accessory nerve and the cervical plexus has been extensively described, the exact motor innervation of the trapezius has been controversial. Attempts to resolve this question have involved anatomic or electrophysiologic studies in human embryos and animals. Extrapolation of the results to adult humans may not be correct. Accurate identification of muscle innervation is obtainable by intra-operative measurement of motor action potentials produced by direct stimulation of the accessory nerve and the cervical plexus. The study involved 14 patients undergoing supraomohyoid or modified neck dissections. Under direct vision, stimulating electrodes were placed on the identified nerves and motor action potentials, and latencies were recorded by surface electrodes placed over the three portions of the trapezius. In 13 patients, when the accessory nerve was stimulated, motor action potentials were obtained in 13 of 13 in the first portion, 11 of 13 in the second portion, and 10 of 13 in the third portion of the trapezius. In the last patient, the accessory nerve ended in the sternocleidomastoid muscle, and innervation of the trapezius was via C3 as demonstrated by motor action potentials. Responses when the roots of the cervical plexus were stimulated varied. Three patterns were seen: In the first group (seven patients), motor action potentials were distinct from those recorded when the accessory nerve was stimulated. Additionally, latencies were different from those of the accessory nerve. The second group (four patients) had motor action potentials that were similar to those obtained from stimulation of the accessory nerve, although their corresponding latencies were different. In two patients, no motor action potentials were recorded when the cervical plexus was stimulated. The results suggest that motor innervation of the trapezius is variable. The accessory nerve, when present, provides the most important input to the trapezius. Motor innervation from the cervical plexus is unpredictable, although it appears to be present in the majority of patient studies.     

Direct coaptation of extensive facial nerve defects after removal of the superficial part of the parotid gland: an anatomic study

BACKGROUND: In the surgical repair of facial nerve paralysis, a tension-free end-to-end coaptation of the trunk or its branches with or without rerouting is functionally superior to grafting. Assuming that a lengthening of all branches of the parotid plexus can be attained by removal of the superficial part of the parotid gland and mobilization of the branches, we performed an anatomic study. METHODS: The parotid regions of 10 cadavers were dissected to investigate the length gained for the branches of the parotid plexus by this technique. Every branch at the upper and ventral border of the gland was marked by a surgical suture. After removing the superficial part of the parotid gland, the branches were cut at the suture, and the proximal stump was drawn toward the distal stump. The distance of the overlapping stumps was measured by means of an electronic gliding caliper. In addition, in five specimens only the trunk of the facial nerve was dissected by the same method, and the distance of the overlapping stumps was measured. RESULTS AND CONCLUSIONS: The results demonstrate that removing the superficial part of the parotid gland may be sufficient to enable direct coaptation without nerve grafting. Cut temporal or zygomatic branches with a gap of up to 15 mm and cut buccal or marginal mandibular branches with a gap of up to 23 mm can be bridged by mobilization of just the proximal stumps. This technique may also be used to bridge a 17-mm gap of the trunk of the facial nerve.     

Functional restoration of the paralyzed diaphragm in high cervical quadriplegia via phrenic nerve neurotization utilizing the functional spinal accessory nerve

The authors report a case of functional improvement of the paralyzed diaphragm in high cervical quadriplegia via phrenic nerve neurotization using a functional spinal accessory nerve. Complete spinal cord injury at the C-2 level was diagnosed in a 44-year-old man. Left diaphragm activity was decreased, and the right diaphragm was completely paralyzed. When the level of metabolism or activity (for example, fever, sitting, or speech) slightly increased, dyspnea occurred. The patient underwent neurotization of the right phrenic nerve with the trapezius branch of the right spinal accessory nerve at 11 months postinjury. Four weeks after surgery, training of the synchronous activities of the trapezius muscle and inspiration was conducted. Six months after surgery, motion was observed in the previously paralyzed right diaphragm. The lung function evaluation indicated improvements in vital capacity and tidal volume. This patient was able to sit in a wheelchair and conduct outdoor activities without assisted ventilation 12 months after surgery.     

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.     

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.     

Considering the spinal accessory nerve in head and neck surgery

Loss of trapezius muscle function represents the single most important source of long-term morbidity from a radical neck dissection. Its preservation has been one of the central features of the conservative or modified neck dissection. We recently undertook an evaluation of 100 consecutive patients who had undergone composite resection for head and neck cancer and examined them with particular emphasis on the function of the trapezius muscle. The mean interval from the time of radical neck dissection to the time of this evaluation was 6.2 years. The operations included radical neck dissection with sacrifice of the spinal accessory nerve, radical neck dissection with preservation of the spinal accessory nerve, and radical neck dissection with interpositioned cable graft reconstruction. The survey showed that 67 percent of the patients who underwent radical neck dissection with sacrifice of the spinal accessory nerve, although they showed profound atrophy of the trapezius muscle, had few symptoms related to this deficit. Similarly, 47 percent of patients who underwent radical neck dissection with preservation of the spinal accessory nerve showed some signs of muscle atrophy, and 20 percent showed little or no function of the muscle. Interpositioned nerve grafts appeared to function well in 66 percent of the patients. The survey showed that a surprising number of patients treated with a standard radical neck dissection and sacrifice of the spinal accessory nerve had few postoperative symptoms related to the loss of trapezius muscle function. Also unexpected was the number of patients with signs of muscle dysfunction despite nerve preservation.     

A clinical evaluation of stumps in lower limb amputees.

A study was carried out on 93 consecutive unilateral below-knee (BK) and 62 above-knee (AK) amputees. The dimensions of the amputation stumps were measured and the general condition and contralateral limb assessed at the time of prosthetic fitting. After one postoperative year, follow-up information for 124 (89%) of the surviving patients was obtained by personal contact. The observations were based on the standard formula for stump classification constructed by the International Society for Prosthetics and Orthotics. The 93 BK stumps had a mean length of 16.0 cm and the 62 AK stumps a mean length of 28.0 cm. The scar on the stump was adherent in 13% of BK and 2% of AK stumps. The scar was deeply wrinkled in 7% of BK stumps and 10% of AK stumps. The scar on the stump was most frequently adherent or deeply wrinkled in trauma patients (33%). The skin was undamaged in 93% of all the patients at the first visit and in 94% at the time of follow-up. The mobility of the stump in the proximal joint was limited at the time of prosthetic fitting in 15% of cases. Phantom pain was reported by 59% and stump pain by 5% of patients at this time. Although the phantom pain was mild in most cases, it was usually still present after one year, and 53% of the surviving patients suffered from phantom pain. At the first visit, 20% of patients had problems in their contralateral leg. During the first postoperative year, 6 contralateral BK amputations were performed in the BK group and one contralateral AK amputation in the AK group. Thus, along with examination of the stump, attention must be paid to the contralateral limb with a view to preserving it. The study supports the usefulness of the standard form and classification of amputation stumps.