Objective comparison of physical dysfunction after neck dissection.

Considering the spinal accessory nerve in head and neck surgery.

To describe landmarks and tips used for minimizing surgical traumas to the spinal accessory nerve, and different options in case of its injury. Modified radical and selective neck dissections reduce the prevalence of shoulder syndrome, a sequela of radical neck dissection. Impaired shoulder mobility and pain may be present even after nerve-sparing procedures, as shown using electromyography, particularly when dissection is extended to level V. In these cases physical therapy is mandatory to prevent shoulder pain and functional limitations. The issue of spinal accessory nerve repair when macroscopically damaged or transected remains critical. Subclinical spinal accessory nerve impairment can be observed even after selective neck dissections (levels II-IV) due to routine clearance of sublevel IIB. Further studies should be performed to select patients in whom this sublevel could be left undissected without impairing oncologic radicality and to demonstrate if such a policy leads to better functional results. Early diagnosis of shoulder syndrome by questionnaires and clinical tests is recommended to appropriately plan physical therapy. Spinal accessory nerve repair is advocated to reduce the prevalence of shoulder syndrome after radical neck dissection. More data are needed to assess the superiority of newer techniques such as nerve transposition or bioresorbable nerve guides.

The X-pointer: A forgotten anatomical relationship of spinal accessory nerve and great auricular nerve

The major complication of neck dissection and surgery at the posterior triangle of the neck is the shoulder syndrome, which results from spinal accessory nerve injury. Erb's point (the great auricular nerve) and the point where the spinal accessory nerve enters the trapezius muscle are used to identify the spinal accessory nerve in the posterior nerve triangle. Measurements were made during unilateral neck dissections in 30 patients to identify the relationship between the spinal accessory nerve and great auricular nerve and the distance between the entrance of the accessory nerve in the trapezious and clavicle. The distance between the spinal accessory nerve and Erb's point was ranging from 0 to 3.8 cm (mean 1.53 cm). The distance between the spinal accessory nerve entering the trapezious muscle and the clavicle was between 2.5 and 7.3 cm (mean 4.8 cm). Since the great auricular nerve (Erb's point) represents a constantly identifiable landmark, it allows simple and reliable identification of the course of the spinal accessory nerve. Also useful, but of secondary importance in our opinion, is identifying the nerve at the point where it enters the trapezius muscle.

The spinal accessory nerve (SAN) is crucial for the motor function of the trapezius and sternocleidomastoid muscles, playing a significant role in scapular stability and upper limb mobility. While SAN injuries are commonly associated with iatrogenic causes such as lymph node biopsies, neck dissections, and posterior cervical trauma, injury following trapezius lipoma resection has not been well-documented. Given the SAN's superficial location and proximity to surgical fields in the posterior cervical triangle, it is vulnerable to inadvertent injury during tumor excision. To the best of our knowledge, this case report presents the first documented instance of isolated SAN mononeuropathy following trapezius lipoma resection and underscores the importance of early recognition, diagnosis, and management. A 54-year-old male developed SAN mononeuropathy following an elective surgical removal of a deep right-sided trapezius lipoma. One week following resection, the patient exhibited new-onset paresthesias in the right upper extremity, scapular dyskinesis, shoulder weakness, and lateral scapular winging. Prior electrodiagnostic (EDX) studies for different complaints showed no signs of peripheral nerve injury. Given the new presentation, repeat EDX were performed six months postoperatively, revealing severe focal SAN neuropathy with ongoing active denervation. The findings suggest direct or traction-related SAN injury rather than an isolated muscular pathology. Given the course of symptoms, a referral to a peripheral nerve surgeon was warranted for recommendations regarding further management. SAN mononeuropathy following lipoma resection is an important and uncommon complication. Most SAN injuries result from iatrogenic causes, such as neck dissections and lymph node biopsiesor lateral neck trauma. The SAN's close proximity to the surgical site makes it susceptible to iatrogenic injury in posterior cervical triangle procedures. This case highlights the importance of identifying lipoma location and recognizing subtle nerve injuries often overlooked without thorough postoperative assessment. Clinical signs include lateral scapular winging during active external rotation, vague shoulder pain, limitations in range of motion, and potential muscle atrophy.In this case, resection of a deeply situated trapezius lipoma led to SAN dysfunction within one week of surgery. Clinical suspicion, combined with examination and confirmation through EDX, highlights the SAN's vulnerability in this region. SAN injury outcomes vary widely, with treatment options ranging from conservative management to surgical interventions such as nerve grafting, nerve repair, or Eden-Lange muscle transfer. Successful recovery is more likely when repairs are performed early, ideally within seven months, with poorer results after 20 months. This case emphasizes the potential for SAN injury during deep trapezius lipoma resection. Early recognition through physical exam and EDX is essential for distinguishing SAN mononeuropathy from other shoulder dysfunctions, as prompt diagnosis improves functional outcomes. Additionally, preoperative nerve mapping is crucial when operating near critical neural structures, stressing the importance of intraoperative nerve monitoring to reduce the risk of injury. Further research is needed to better understand SAN injury incidence in posterior cervical and scapular surgeries and to develop standardized management guidelines.

Lateral neck dissection (LND) leads to a significant morbidity involving accessory nerve injury. Modified radical neck dissection (MRND) aims at preservation of the accessory nerve, but patients often present with negative functional outcomes after surgery. The role of neuromonitoring (IONM) in the prevention of shoulder syndrome has not yet been defined in comparison to nerve visualization only. We retrospectively analyzed 56 thyroid cancer patients who underwent MRND over a period of six years (2015–2020) in a high-volume institution. Demographic variables, type of surgical procedure, removed lymph nodes and the metastatic node ratio, pathology, adoption of IONM and shoulder functional outcome were investigated. The mean number of lymph nodes removed was 15.61, with a metastatic node ratio of 0.2745. IONM was used in 41.07% of patients, with a prevalence of 68% in the period 2017–2020. IONM adoption showed an effect on post-operative shoulder function. There were no effects in 89.29% of cases, and temporary and permanent effects in 8.93% and 1.79%, respectively. Confidence intervals and two-sample tests for equality of proportions were used when applicable. Expertise in high-volume centres and IONM during MRND seem to be correlated with a reduced prevalence of accessory nerve lesions and limited functional impairments. These results need to be confirmed by larger prospective randomized controlled trials.

ObjectiveWe propose a standardized approach of using the tendon of the sternocleidomastoid (SCM) muscle to locate the spinal accessory nerve (SAN) in neck dissection.Study DesignCross-sectional anatomic study.SettingTertiary academic medical center.MethodsAdult patients aged ≥18 years undergoing primary neck dissection for head and neck cancer were included. Anatomic measurements included the length of the SCM tendon, the distance from the mastoid tip to the entrance of the SAN into the SCM, the distance from the SAN to the distal edge of the SCM tendon, and the perpendicular distance from the anterior edge of the SCM to the SAN. Five cadaveric specimens also underwent bilateral modified radical neck dissections with the same anatomic measurements taken.ResultsTwenty-two living subjects and 5 cadavers were included. No statistical correlation was noted between patient demographics and any measurement. The mean (SD) length of the SCM tendon was 63.7 mm (11.8) in living subjects and 61.5 mm (10.4) in cadaveric specimens. The average distance from the mastoid tip to the entrance of SAN into the SCM was 51.6 mm (12.2) in living subjects and 51.6 mm (7.1) in cadaveric subjects. The distance of the SAN insertion into the SCM muscle from the anterior edge was 8.9 mm (3.4) in living subjects and 16.2 mm (7.2) in cadaver specimens. Laterality was compared in the cadaveric specimens; there was no statistically significant difference in any of the measurements between sides.ConclusionThis study demonstrates the SCM tendon to be a reliable and safe surgical landmark to identify and preserve the SAN during neck dissection.

Background: The spinal accessory nerve (SAN) may damage during its dissection from the sternocleidomastoid (SCM) muscle during modified neck dissection type II due to their intimate relation. Routinely, it is dissected from the anterior aspect of the SCM. The aim of this study is to describe and simplify the safer dissection of the SAN from the SCM muscle. Objectives: We proposed a different method of dissection describing it to be posterior approach. Materials and Methods: Posterior dissection of SAN was done as routine. Conclusion: Although more studies are required to depict the superiority of one over another, we found this method to be easier and time-saving approach.

For decades, the gold standard for treatment of cervical metastasis was radical neck dissection (RND). Current oncologic philosophy allows for treatment of appropriately staged neck disease with modified radical neck dissection (MRND) or selective neck dissection (SND). The purposes of this study were to determine the impact of various forms of neck dissection on patients' quality of life (QOL) and to evaluate the responsiveness of the University of Washington (UW) QOL shoulder domain. Prospective accumulation of QOL data from patients treated for head and neck cancer at UW. Eighty-four patients were identified from the UW QOL registry who had undergone neck dissection and had completed pretreatment and posttreatment QOL questionnaires at 6 and 12 months. Compared with pretreatment scores, the MRND and RND groups reported worse shoulder function at 6 and 12 months (P<.0005). The MRND group reported greater shoulder disability at 6 months compared with the SND group (P = .002), but by 12 months, there was no difference between the two groups. Shoulder function for the RND group was worse than the SND group at 6 and 12 months (P = .004). There was a trend toward decreased pain after treatment in the SND and MRND groups. There were no significant differences in subjective appearance, activity, recreation, chewing, swallowing, or speech in the three groups after treatment. Consistent with findings of published functional studies, this study confirmed that the three forms of neck dissection affect patients' QOL differently. This study demonstrates that the UW QOL shoulder domain is a responsive instrument in assessing the effect of neck dissection on shoulder function.

Background The spinal accessory nerve (SAN) has several anatomical variations, which may be a pitfall in neck dissection (ND). These include the trapezius muscle branch (TB), which stems from the common trunk before entering the sternocleidomastoid muscle (SCM). Aims/Objectives To investigate the prevalence of this variation and suggest a protocol for preventing unexpected injury of the TB in ND. Materials and methods We conducted a retrospective cohort study for 93 patients who had undergone neck dissection (117 sides) without resection of the SCM nor SAN. We recorded the division of the TB after and before penetration of the SCM by the common trunk (penetrating type TB [PTB]) and non-penetrating type TB [NPTB], respectively). Results Among NDs, PTB and NPTB were observed in 61 (52%) and 56 (48%) sides, respectively. In the subgroup of 24 cases with bilateral ND, PTB/PTB, NPTB/NPTB, and NPTB/PTB were observed in eight (33%), nine (38%), and seven (29%) cases, respectively. The prevalence of PTB/NPTB did not differ according to age, sex, or laterality. Conclusions and significance NPTB is a common anatomical variation. The presence or absence of a branch from the common trunk must be initially checked to avoid unexpected damage to the TB.

Conclusion: The results of this study accord with those of past reports about the prevalence of level V metastasis in head and neck squamous cell carcinoma (HNSCC) cases. Because of the low rate of level V metastasis, and from the viewpoint of standard postoperative radiotherapy, selective neck dissection without level V dissection may be possible in cases without clinical evidence of level V metastasis on both the ipsilateral and contralateral sides. In addition, degree of pathological differentiation and pN stage >N2b are suggested risk factors for level V metastasis. Objectives: The most frequent complication of any type of neck dissection in HNSCC cases with level V metastasis is shoulder dysfunction secondary to traction or ischemic injury to the spinal accessory nerve (SAN). The purpose of this study was to examine procedures to preserve the SAN and avoid level V dissection and shoulder dysfunction due to SAN injury. This study investigated the prevalence of level V metastasis and its associated risk factors at various primary sites in patients with HNSCC. Methods: Clinical and pathological data were retrospectively reviewed for 162 patients with HNSCC, including those with clinically negative neck (cN0) and clinically positive neck (cN+) in whom level V neck dissection was performed. The prevalence of pathological metastasis to level V lymph nodes on both the ipsilateral and contralateral sides was investigated. Several potentially predictive risk factors for level V metastasis, such as age, sex, primary site, T stage, N stage, degree of pathological differentiation, and lymph node status of levels I–IV, were also evaluated. Statistical analysis was performed using Fisher's exact test. Results: In total, 301 neck dissections (ipsilateral side, n = 162; contralateral side, n = 139) were performed in this study. The most common primary site was the oral cavity (n = 51), followed by the larynx (n = 48), hypopharynx (n = 39), and oropharynx (n = 24). On the ipsilateral side, the overall incidence of pathologically positive neck (pN+) was 63.6% (103/162). The overall prevalence of level V metastasis was 7.4% (12/162), 6.8% (11/162) on the ipsilateral side, and 1.4% (2/139) on the contralateral side. Isolated level V metastasis and bilateral level V metastasis was observed in three patients and one patient, respectively. Metastasis to level V and other levels was observed in eight patients (8/96, 8.3%), and level V involvement on the ipsilateral side alone was observed only in three patients (3/66, 4.5%). There were two cases in which level V was involved when the other levels were also involved (2/22, 9.1%), and there was no case in which the other levels were not involved on the contralateral side. A statistically significant association was found between level V metastasis and pN stage >N2b (p = 0.0035), degree of pathological differentiation (p = 0.0305) on the ipsilateral side, status of neck levels I–IV (p = 0.001), and the number of positive neck levels (p < 0.0001) on the contralateral side.

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.

CHAPTER 17 - Radical Neck Dissection

OBJECTIVE Transfer of the spinal accessory nerve to the suprascapular nerve is a common procedure, performed to reestablish shoulder motion in patients with total brachial plexus palsy. However, the results of this procedure remain largely unknown. METHODS Over an 11-year period (2002-2012), 257 patients with total brachial plexus palsy were operated upon in the authors' department by a single surgeon and had the spinal accessory nerve transferred to the suprascapular nerve. Among these, 110 had adequate follow-up and were included in this study. Their average age was 26 years (SD 8.4 years), and the mean interval between their injury and surgery was 5.2 months (SD 2.4 months). Prior to 2005, the suprascapular and spinal accessory nerves were dissected through a classic supraclavicular L-shape incision (n = 29). Afterward (n = 81), the spinal accessory and suprascapular nerves were dissected via an oblique incision, extending from the point at which the plexus crossed the clavicle to the anterior border of the trapezius muscle. In 17 of these patients, because of clavicle fractures or dislocation, scapular fractures or retroclavicular scarring, the incision was extended by detaching the trapezius from the clavicle to expose the suprascapular nerve at the suprascapular fossa. In all patients, the brachial plexus was explored and elbow flexion reconstructed by root grafting (n = 95), root grafting and phrenic nerve transfer (n = 6), phrenic nerve transfer (n = 1), or third, fourth, and fifth intercostal nerve transfer. Postoperatively, patients were followed for an average of 40 months (SD 13.7 months). RESULTS Failed recovery, meaning less than 30° abduction, was observed in 10 (9%) of the 110 patients. The failure rate was 25% between 2002 and 2004, but dropped to 5% after the staged/extended approach was introduced. The mean overall range of abduction recovery was 58.5° (SD 26°). Comparing before and after distal suprascapular nerve exploration (2005-2012), the range of abduction recovery was 45° (SD 25.1°) versus 62° (SD 25.3°), respectively (p = 0.002). In patients who recovered at least 30° of abduction, recovery of elbow flexion to at least an M3 level of strength increased the range of abduction by an average of 13° (p = 0.01). Before the extended approach, 2 (7%) of 29 patients recovered active external rotation of 20° and 120°. With the staged/extended approach, 32 (40%) of 81 recovered some degree of active external rotation. In these patients, the average range of motion measured from the thorax was 87° (SD 40.6°). CONCLUSIONS In total palsies of the brachial plexus, using the spinal accessory nerve for transfer to the suprascapular nerve is reliable and provides some recovery of abduction for a large majority of patients. In a few patients, a more extensive approach to access the suprascapular nerve, including, if necessary, dissection in the suprascapular fossa, may enhance outcomes.

Preservation of the spinal accessory nerve during neck dissection should be the rule rather than the exception. Despite the presence of many described techniques to locate the nerve, a tedious dissection is often required; as a consequence, it remains vulnerable to damage. We describe a novel method, not previously reported, based on identifying a constant vein which crosses the nerve. This aids in the nerve's early identification. Our method enables the surgeon to locate the nerve precisely and to avoid damage to it, thereby maximizing post-operative function.