Management of the facial nerve in parotid cancer: preservation or resection and reconstruction

Delayed repair of the facial nerve and its negative impacts on nerve and muscle regeneration

Background

In this experimental protocol, we evaluated the immediate and delayed repair of the buccal branch of the facial nerve (BBFN) with heterologous fibrin biopolymer (HFB) as a coaptation medium and the use of photobiomodulation (PBM), performing functional and histomorphometric analysis of the BBFN and perioral muscles.

Methods

Twenty-eight rats were divided into eight groups using the BBFN bilaterally (the left nerve was used for PBM), namely: G1 - control group, right BBFN (without injury); G2 - control group, left BBFN (without injury + PBM); G3 - Denervated right BBFN (neurotmesis); G4 - Denervated left BBFN (neurotmesis + PBM); G5 - Immediate repair of right BBFN (neurotmesis + HFB); G6 - Immediate repair of left BBFN (neurotmesis + HFB + PBM); G7 - Delayed repair of right BBFN (neurotmesis + HFB); G8 - Delayed repair of left BBFN (neurotmesis + HFB + PBM). Delayed repair occurred after two weeks of denervation. All animals were sacrificed after six weeks postoperatively.

Results

In the parameters of the BBFN, we observed inferior results in the groups with delayed repair, in relation to the groups with immediate repair, with a significant difference (p < 0.05) in the diameter of the nerve fiber, the axon, and the thickness of the myelin sheath of the group with immediate repair with PBM compared to the other experimental groups. In measuring the muscle fiber area, groups G7 (826.4 ± 69.90) and G8 (836.7 ± 96.44) were similar to G5 (882.8 ± 70.51). In the functional analysis, the G7 (4.10 ± 0.07) and G8 (4.12 ± 0.08) groups presented normal parameters.

Conclusion

We demonstrated that delayed repair of BBFN is possible with HFB, but with worse results compared to immediate repair, and that PBM has a positive influence on nerve regeneration results in immediate repair.

An analysis of health-related quality of life in children and adolescents after parotidectomy based on patient-reported outcomes

PURPOSE

To assess health-related quality of life (HRQoL) and its influencing factors in these pediatric patients undergoing parotidectomy.

METHODS

This was a cross-sectional study that included 37 children and adolescents (≤ 19 years) with parotid gland tumors who were treated in Sichuan Cancer Hospital between January 2006 and November 2021. HRQoL was assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30 (EORTC QLQ-C30). The Wilcoxon rank sum test was used to analyze the factors influencing patients' HRQoL.

RESULTS

37 children and adolescents were included in the study, including 22 cases of benign tumors and 15 cases of malignant tumors. All patients underwent surgery, and some patients with malignant tumors received radiotherapy or chemotherapy. Malignancy, permanent facial palsy, and Frey syndrome were associated with worse HRQoL in children and adolescents with parotid gland tumors. Radiotherapy and no cervical lymph node dissection were associated with worse HRQoL in pediatric patients with malignancy. The surgical approach of parotid is not a factor influencing HRQoL.

CONCLUSION

Factors associated with HRQoL in children and adolescents with parotid gland tumors include pathological types, permanent facial palsy, and Frey syndrome. In addition, factors affecting patients with malignancy include lateral lymph node dissection and radiotherapy.

Surgery of major salivary gland cancers: REFCOR recommendations by the formal consensus method

OBJECTIVE

To determine the role of surgery of the primary tumor site in the management of primary major salivary gland cancer.

MATERIAL AND METHODS

The French Network of Rare Head and Neck Tumors (REFCOR) formed a steering group, which drafted a non-systematic narrative review of the literature published on Medline, and proposed recommendations. The level of adherence to the recommendations was then assessed by a rating group, according to the formal consensus method.

RESULTS

Treatment of salivary gland tumor is mainly surgical. The gold standard for parotid cancer is a total parotidectomy, to obtain clear margins and remove all intraparotid lymph nodes. For low-grade tumors, partial parotidectomy with wide excision of the tumor is acceptable in the case of postoperative diagnosis on definitive histology. In the event of positive margins on definitive analysis, revision surgery should be assessed for feasibility, and performed if possible.

CONCLUSION

Treatment of primary major salivary gland cancer is based on surgery with clear resection margins, as far away as possible from the tumor. The type of surgery depends on tumor location, pathologic type and extension.

Immediate lengthening temporalis myoplasty for facial palsy reconstruction following facial nerve inclusive total parotidectomy

Immediate lengthening temporalis myoplasty (Labbé procedure) for immediate dynamic facial reanimation after nerve-inclusive parotidectomy in the elderly population is undocumented in the literature. The aim of this work was to determine whether the Labbé approach could achieve immediate, good functional and static results in elderly patients with acquired facial palsy. A retrospective analysis of five patients with parotid malignancies involving the facial nerve who underwent parotidectomy and an immediate Labbé procedure was performed. The House-Brackmann and Sunnybrook scores for facial palsy were used as objective measurements of the functional outcome. All patients underwent total parotidectomy, neck dissection, Labbé procedure, immediate temporary tarsorrhaphy, brow lift, and postoperative radiotherapy. Mean patient age was 83 (range 73-87) years. The average resected tumour size was 3.54 cm. The mean duration of surgery was 324 min and length of hospital stay 4 days. All patients experienced an improvement in House-Brackmann of one grade postoperative (grade V to IV in four, grade VI to V in one); the Sunnybrook score improved by 31 points on average (mean preoperative 3.8 vs postoperative 34.8). An immediate Labbé procedure following ablative parotid malignancy resection is a reliable and safe reconstructive procedure in a carefully selected elderly population, providing acceptable immediate static and dynamic hemifacial mimetic function and eliminating an additional facial palsy correction procedure.

Research trends and perspectives on immediate facial reanimation in radical parotidectomy (Review)

For patients diagnosed with advanced malignant parotid tumour, radical parotidectomy with facial nerve sacrifice is part of the treatment. Multiple surgical techniques have been developed to cure facial paralysis in order to restore the function and aesthetics of the face. Despite the large number of publications over time on facial nerve reanimation, a consensus on the timing of the procedure or the donor graft selection has remained to be established. Therefore, the aim of the present study was to conduct a bibliometric analysis to identify and analyse scientific publications on the reconstruction of the facial nerve of patients who underwent radical parotidectomy with facial nerve sacrifice. The analysis on the topic was conducted using the built-in tool of the Scopus database and VOSviewer software. The first 100 most cited articles were separately reviewed to address the aim of the study. No consensus was found regarding the recommended surgical techniques for facial nerve reanimation. The most used donor cranial nerves for transfer included the following: Masseteric branch of the V nerve, contralateral VII nerve with cross-face graft, the XI nerve and the XII nerve. The best timing of surgery is also controversial depending on pre-exiting pathology and degree of nerve degeneration. However, most of the clinical experience suggests facial nerve restoration immediately after the ablative procedure to reduce complications and improve patients' quality of life.

Could definitive radiotherapy be a treatment option for lymphoepithelial carcinoma of major salivary gland: Comparison of clinical outcomes of upfront surgery and upfront chemoradiotherapy

OBJECTIVES

The optimal treatment and associated clinical outcomes for lymphoepithelial carcinoma of the major salivary gland (LECSG) are currently unclear. As such, the purpose of this study was to assess the survival rates of LECSG patients who received either upfront surgery or upfront chemoradiotherapy (CRT).

MATERIALS AND METHODS

In this retrospective study, we analyzed cases of LECSG patients treated at our center from January 2010 to April 2021. The cumulative incidences of overall survival rate (OS) and locoregional failure-free survival rate (LRFFS) were evaluated using the Kaplan-Meier method. In order to balance potential risk factors between the treatment groups, we conducted propensity score matching (PSM) at a 1:1 ratio.

RESULTS

The study enrolled a total of 107 patients, among whom 24 received surgery alone, 56 underwent surgery combined with postoperative radiotherapy, and 27 underwent definitive radiotherapy. The 5-year LRFFS rate and 5-year OS rate for the entire cohort were 86.6% and 84.4%, respectively. Following PSM, the 5-year LRFFS and OS rates for the upfront CRT cases were comparable to those of upfront surgery, both before and after matching. However, the upfront surgery group showed a tendency toward more de novo facial nerve injury and post-treatment facial nerve injury.

CONCLUSION

The results of this study suggest that upfront CRT is as effective as upfront surgery in terms of locoregional control and overall survival for LECSG patients. Therefore, upfront CRT could be considered a viable treatment option, potentially avoiding the risks associated with surgical intervention.

Morphofunctional Improvement of the Facial Nerve and Muscles with Repair Using Heterologous Fibrin Biopolymer and Photobiomodulation

Peripheral nerve injuries impair the patient's functional capacity, including those occurring in the facial nerve, which require effective medical treatment. Thus, we investigated the use of heterologous fibrin biopolymer (HFB) in the repair of the buccal branch of the facial nerve (BBFN) associated with photobiomodulation (PBM), using a low-level laser (LLLT), analyzing the effects on axons, muscles facials, and functional recovery. This experimental study used twenty-one rats randomly divided into three groups of seven animals, using the BBFN bilaterally (the left nerve was used for LLLT): Control group-normal and laser (CGn and CGl); Denervated group-normal and laser (DGn and DGl); Experimental Repair Group-normal and laser (ERGn and ERGl). The photobiomodulation protocol began in the immediate postoperative period and continued for 5 weeks with a weekly application. After 6 weeks of the experiment, the BBFN and the perioral muscles were collected. A significant difference (p < 0.05) was observed in nerve fiber diameter (7.10 ± 0.25 µm and 8.00 ± 0.36 µm, respectively) and axon diameter (3.31 ± 0.19 µm and 4.07 ± 0.27 µm, respectively) between ERGn and ERGl. In the area of muscle fibers, ERGl was similar to GC. In the functional analysis, the ERGn and the ERGI (4.38 ± 0.10) and the ERGI (4.56 ± 0.11) showed parameters of normality. We show that HFB and PBM had positive effects on the morphological and functional stimulation of the buccal branch of the facial nerve, being an alternative and favorable for the regeneration of severe injuries.

Imaging of Major Salivary Gland Lesions and Disease

Infectious and inflammatory disorders are the commonest pathologies to affect the major salivary glands however frequently overlap in clinical presentation. Imaging plays an important role in diagnosis, usually initially performed by CT or ultrasound. MRI, with its superior soft-tissue characterization compared with CT, provides a better evaluation of tumors and tumor-like conditions. Imaging features may suggest that a mass is more likely to be benign versus malignant, however, biopsy is often needed to establish a definitive histopathologic diagnosis. Imaging plays a key role in the staging of neoplastic disease.

Prognostic risk factor of major salivary gland carcinomas and survival prediction model based on random survival forests

Salivary gland malignancies are rare and are often acompanied by poor prognoses. So, identifying the populations with risk factors and timely intervention to avoid disease progression is significant. This study provides an effective prediction model to screen the target patients and is helpful to construct a cost-effective follow-up strategy. We enrolled 249 patients diagnosed with salivary gland tumors and analyzed prognostic risk factors using Cox proportional hazard univariable and multivariable regression models. The patients' data were split into training and validation sets on a 7:3 ratio, and the random survival forest (RSF) model was established using the training sets and validated using the validation sets. The maximally selected rank statistics method was used to determine a cut point value corresponding to the most significant relation with survival. Univariable Cox regression suggested age, smoking, alcohol consumption, untreated, neural invasion, capsular invasion, skin invasion, tumors larger than 4 cm, advanced T and N stage, distant metastasis, and non-mucous cell carcinoma were risk factors for poor prognosis, and multivariable analysis suggested that female, aging, smoking, untreated, and non-mucous cell carcinoma were risk factors. The time-dependent ROC curve showed the AUC of the RSF prediction model on 1-, 2-, and 3-year survival were 0.696, 0.779, and 0.765 respectively in the validation sets. Log-rank tests suggested that the cut point 7.42 risk score calculated from the RSF was most effective in dividing patients with significantly different prognoses. The prediction model based on the RSF could effectively screen patients with poor prognoses.

[Posttherapeutic quality of life after treatment of salivary gland cancer]

BACKGROUND

In addition to overall survival and recurrence-free interval, posttherapeutic quality of life has been established as an independent criterion for treatment evaluation. Thereby, both the specific changes in the head and neck region and their objectification represent a particular challenge for the assessment of quality of life. There are different validated questionnaires available.

OBJECTIVE

Based on the literature, an overview of the relevant questionnaire instruments is given and the specific aspects in patients with salivary gland cancer are presented.

MATERIALS AND METHODS

A selective literature search was conducted to collect publications dealing with the assessment of health-related quality of life in head and neck tumor patients. The papers were critically appraised and summarized.

RESULTS

There are some validated questionnaires available to measure quality of life in patients with head and neck tumors as well as a few specific questionnaires for patients after parotidectomy.

CONCLUSION

By assessing quality of life using standardized questionnaire instruments, disease and treatment consequences can be objectified. Thus, the need for supportive measures, e.g., for rehabilitation in facial nerve palsy, can be identified more reliably.

Survival in Patients with Primary Parotid Gland Carcinoma after Surgery—Results of a Single-Centre Study

This study aims to analyse a single-centre cohort series of patients who underwent parotidectomy for primary malignant parotid tumours. A retrospective chart review of 64 consecutive patients treated from November 2010 to March 2022 was performed. Outcomes were analysed by Kaplan-Meier curves. Sixty-four patients with a primary parotid malignancy were included in the study, with one bilateral case in this cohort. Patients were classified as stage I–II in 39 cases and stage III–IV in 26 cases. The five-year overall survival (OS), disease-specific survival (DSS), local relapse-free survival (LRFS), and distant metastasis-free survival (DMFS) rates were 78.4%, 89%, 92.5%, and 87.1%, respectively. Univariate analysis showed that high-risk histology, stage IV disease, lymphovascular invasion, perineural invasion, node metastasis, skin involvement, facial nerve involvement, and positive or close margins were risk factors associated with poorer outcomes. At present, the best evidence suggests that radical surgery should be the standard approach, and adjuvant therapy, in terms of radiotherapy/chemoradiotherapy, is recommended in patients with risk factors.

Parotid metastases from primary lung cancer: Case series and systematic review of the features

Most parotid metastases have been reported to come from the head and neck; however, cases metastasized from the lung are extremely rare. Missed diagnoses and misdiagnoses occurred quite a few times. Thus, accurately identifying the clinical features of parotid metastasis of lung cancer is important. However, current studies about this issue are mostly case reports, and little is known about the detailed and systematic aspects. We reported three cases of parotid metastases from lung cancer and then systematically searched similar cases through “Pub-Med” and “Web of Science”. Finally, twenty-three patients were included in the study. Eighty-three percent of which were males, and 19 patients were over 50 years old. In all cases with smoking history mentioned, 93% were smokers. The predominant pathological type was small cell lung cancer (SCLC, 13 patients, 56%). Seventeen combined with other site metastasis, while more than half of which were brain metastases. The survival time ranged from 3months-17years, and as for SCLCs, it was only 3months-40months. It can be concluded that clinical features, such as sex, age, smoking history, pathological types, and metastasis patterns, could provide valuable evidence for diagnosis. The lung seems to be the most common primary site of parotid metastases except for head and neck tumors. The two circumstances, SCLC coexisting with Warthin’s tumor and parotid small cell carcinoma with lung metastasis, should be differentiated from parotid metastasis of lung cancer with caution For cases presented as SCLC, more aggressive strategies, such as chemotherapy with immunotherapy and maintenance therapy, may be more suitable. Due to the greater tendency of brain metastasis in such diseases, whole-brain radiation therapy, stereotactic radiosurgery or prophylactic cranial irradiation should be applied to corresponding patients in time. Additionally, lung cancer parotid metastases may be a marker of poor prognosis.

Role of Intraparotid and Neck Lymph Node Metastasis in Primary Parotid Cancer Surgery: A Population-Based Analysis

This population-based study investigated the prognostic role of intraparotid (PAR) and cervical lymph node (LN) metastasis on overall survival (OS) of primary parotid cancer. All 345 patients (median age: 66 years; 43% female, 49% N+, 31% stage IV) of the Thuringian cancer registries with parotid cancer from 1996 to 2016 were included. OS was assessed in relation to the total number of removed PAR and cervical LN, number of positive intraparotid (PAR+), positive cervical LN, LN ratio, log odds of positive LN (LODDS), as well as including the PAR as LODDS-PAR. PAR was assessed in 42% of the patients (22% of these PAR+). T and N classification were not independent predictors of OS. When combining T with LODDS instead of N, higher T (T3/T4) became a prognosticator (hazard ratio (HR) = 2.588; CI = 1.329−5.040; p = 0.005) but not LODDS (p > 0.05). When combining T classification with LODDS-PAR, both higher T classification (HR = 2.256; CI = 1.288−3.950; p = 0.004) and the alternative classification with LODDS-PAR (≥median −1.11; HR 2.078; CI = 1.155−3.739; p = 0.015) became independent predictors of worse OS. LODDS-PAR was the only independent prognosticator out of the LN assessment for primary parotid cancer.

Management and outcome of parotid mucoepidermoid carcinoma by histological grade: A 21‐year review

Objective

Mucoepidermoid carcinoma (MEC) is the most common malignancy of the parotid gland, but the outcome depends on the histological grade. Therefore, the aim of this study was to evaluate MEC on the basis of histological grade.

Study Design

Retrospective analysis.

Methods

We performed a retrospective analysis of data from patients whose initial treatment for MEC of the parotid gland was performed at our department between 1999 and 2021. We examined the association between the Armed Forces Institute of Pathology (AFIP) grade and outcome.

Results

The AFIP grades were as follows: low, 26 cases; intermediate, 9 cases; and high, 31 cases. About 50% of cases were correctly diagnosed as malignant, and both grade and histology were accurately determined by fine‐needle aspiration cytology in 20% of cases. The 5‐year disease‐free survival rate was 95.5% and 53.8% in the low‐/intermediate‐ and high‐grade cases, respectively. In the high‐grade group, cases with recurrence were found to have a higher rate of lymph nodes metastasis than cases without recurrence. Furthermore, in this high‐grade group, total sacrifice of the facial nerve did not reduce local recurrence. However, radical resection in the cases without tumor invasion to the nerve has decreased the local recurrence rate. The CRTC1‐MAML2 fusion gene was expressed in 42.3% of low‐/intermediate‐ and 14.3% of high‐grade cases.

Conclusions

The survival rate in MEC was quite different between the low‐/intermediate‐ and high‐grade cases. However, the rate of correct assessment of the grade by fine‐needle aspiration cytology was poor. In high‐grade cases, total sacrifice of the facial nerve may improve the rate of local recurrence in cases without invasion of the main trunk of the nerve. Expression of the CRTC1‐MAML2 fusion gene could be helpful in not only the assessment of grade but the prediction of recurrence.

Level of Evidence

4

[Surgery for parotid gland cancer-controversial and proven aspects]

BACKGROUND

Due to the rarity of primary parotid malignancies, there are currently only limited clinical study data on the optimal surgical therapy. Parotid malignancies encompass a broad spectrum of more than 20 different histological subtypes with varying biology, which thus represents a challenge for even experienced pathologists and head and neck surgeons with proven expertise in salivary gland surgery.

OBJECTIVE

The aim of this review article is to provide an overview of the current literature on surgical therapy of the primary tumor and the cN0 neck as well as treatment of the facial nerve, and to shed light on the various controversial aspects of this topic.

RESULTS

In salivary gland oncology there is a trend towards safe (R0) but more conservative surgery. Currently, less-invasive surgical approaches could potentially be applied in a small subgroup with carefully selected caudally located and R0-resected "low-grade tumors" in stages T1-T2 and cN0 in relatively young patients with high compliance and more in the context of structured clinical studies. Elective neck dissection in the case of cN0 status should be carried out if risk factors for occult cervical lymph node metastasis (T3-T4a, "high-grade subtypes," advanced age, lymphangitic carcinomatosis) are present. In cases of small "low-grade parotid carcinomas," narrow resection margins or even microscopic tumor residues on the facial nerve can potentially be adequately compensated with adjuvant radiation therapy. However, due to the lack of solid data, the significance of the actual effect of the radiation in this situation should be viewed with great caution.

[Preservation, reconstruction, and rehabilitation of the facial nerve]

Der Umgang mit dem N. facialis ist bei der Operation eines Parotiskarzinoms wichtig für die Langzeitlebensqualität des Patienten. In etwa 2 Drittel der Fälle ist der N. facialis nicht vom Tumor befallen. In diesen Fällen sind neben vollständiger Tumorentfernung die Identifizierung und der Erhalt des Nervs für eine erfolgreiche Operation wesentlich. Ist der Nerv vom Tumor infiltriert, muss der betroffene Teil des Nervs im Rahmen einer radikalen Parotidektomie reseziert werden. Die primäre Nervenrekonstruktion, sofern möglich, führt zu den besten funktionellen und kosmetischen Langzeitergebnissen. Das individuell optimale Therapiekonzept basiert zum einen auf der klinischen Prüfung der Gesichtsbeweglichkeit, zum anderen auf der präoperativen Bildgebung, um die Lagebeziehung zwischen Tumor und Nerv zu verstehen, und schließlich auf einer elektrophysiologischen Untersuchung zur Funktion des Nervs. Intraoperativ hilft ein standardisiertes Vorgehen, um den Nerv zu identifizieren und zu erhalten. Wenn eine radikale Parotidektomie indiziert ist, kann bereits die präoperative Diagnostik helfen, neben der einzeitigen Rekonstruktion auch die adjuvante postoperative Therapie zu planen. Das Ziel der Rehabilitation ist die Wiederherstellung von Tonus, Symmetrie und Bewegung des gelähmten Gesichts. Die Wiederherstellung des Augenschlusses hat hohe Priorität. Bei der chirurgischen Therapie von Gesichtslähmungen gab es in den letzten Jahren viele Verbesserungen. Die vorliegende Arbeit gibt einen Überblick über die jüngsten Fortschritte in der Diagnostik, den Operationstechniken und weiteren Möglichkeiten zur Protektion des gesunden N. facialis. Anderseits wird die Rehabilitation des tumorinfiltrierten N. facialis im Kontext der Behandlung von Speicheldrüsenmalignomen beschrieben.

The potential applicability of facial nerve monitoring as a navigation tool in parotid gland surgery

OBJECTIVES

The aim of this study was to assess the relationship between the stimulation amplitude and the distance to the facial nerve.

METHODS

This study was designed as a prospective clinical study. A total of 20 patients (12 males, 8 females) were included. Partial superficial parotidectomy was performed in all patients with intraoperative facial monitoring. Measurements were made on the main trunk and major branches. Stimulation was started at 1 mA and incrementally increased to 2 and 3 mA's. The shortest distance creating a robust response (>100 mV) was recorded.

RESULTS

At 1 mA, 2 mA and 3 mA stimulation intensity, the average distance between the tip of the stimulation probe and the main trunk was 2.20 ± 0.76 mm (range 1-3 mm), 3.80 ± 0.95 mm (range 2-5 mm), 4.80 ± 1.05 mm (range 3-7 mm) respectively. The stimulus intensity was inversely proportional in respect to the distance between the nerve and the tip of the stimulus probe (P < .00). The same relation was present in the facial nerve major branch measurements (P < .00).

CONCLUSION

The proportional stimulation amplitude and distance to the facial nerve is thought to be a reliable auxillary method to assist the surgeon by facilitating the estimation of the distance to the facial nerve during extracapsular dissection and minimally invasive cases where the facial nerve isn't routinely dissected.

LEVEL OF EVIDENCE

Level 3.

Frozen Section of Parotid Gland Tumours: The Head and Neck Pathologist as a Key Member of the Surgical Team

Introduction: The aim of this study was to evaluate the impact of subspecialised head and neck versus general surgical pathologists on the reliability of the histopathologic evaluation during intraoperative consultation. Materials and Methods: The medical records of all patients who underwent a parotidectomy with frozen section between 2006 and 2021 were retrospectively evaluated. The frozen section was evaluated for sensitivity, specificity, accuracy, and predictive value. Assessment by two groups of pathologists (subspecialised head and neck versus general surgical pathologists) was compared, and the nature or types of misdiagnoses compared with final diagnoses on paraffin sections were analysed for the two groups. Results: Our study sample was made up of 669 cases. The mean age of patients was 57.7 years (range: 10−94 years). Of these, 490 patients had a benign lesion (73.2%), whereas 179 patients had a malignant lesion (26.8%). Frozen section had an overall accuracy of 97.6%, sensitivity for malignancy was 91.1%, specificity was 100%, PPV was 100%, and the NPV was 96.8%. The exact histologic subtype in the group of malignant tumours was correctly identified in FS in 89.4% of cases. A comparison of head and neck pathologists versus general surgical pathologists revealed a highly statistically significant difference concerning both overall detection of malignancy (p < 0.001) as well as correct identification of the histologic subtype (p < 0.001). Conclusion: Involvement of subspecialised head and neck pathologists in the intraoperative consultation for salivary gland tumours results in a gain of 19.8% more sensitivity, underlining the importance of specialisation in salivary gland pathology for the optimisation of frozen section quality.

The Offprint of an Abnormal Pre-Parotidectomy Electrodiagnostic Finding in a Normally Functioning Facial Nerve: Correlation with Intraoperative Findings, Histology and Postoperative Facial Nerve Function

The aim of this study was to search for associations between an electrodiagnostically abnormal but clinically normal facial nerve before parotidectomy and the intraoperative findings, as well as the postoperative facial nerve function. The records of all patients treated for parotid tumors between 2002 and 2021 with a preoperative House–Brackmann score of grade I but an abnormal electrophysiologic finding were studied retrospectively. A total of 285 patients were included in this study, and 222 patients had a benign lesion (77.9%), whereas 63 cases had a malignant tumor (22.1%). Electroneurographic facial nerve involvement was associated with nerve displacement in 185 cases (64.9%) and infiltration in 17 cases (6%). In 83 cases (29.1%), no tumor–nerve interface could be detected intraoperatively. An electroneurographic signal was absent despite supramaximal stimulation in 6/17 cases with nerve infiltration and in 17/268 cases without nerve infiltration (p < 0.001). The electrophysiologic involvement of a normal facial nerve is not pathognomonic for a malignancy (22%), but it presents a rather rare (~6%) sign of a “true” nerve infiltration and could also appear in tumors without any contact with the facial nerve (~29%). Of our cases, two thirds of those with an anatomic nerve preservation and facial palsy had already directly and postoperatively recovered to a major extent in the midterm.

Is Revision Surgery Necessary for Patients With High Risk of Recurrence After Parotidectomy? A Multicenter Retrospective Study

OBJECTIVES

Close margin is a frequent situation after parotidectomy. The need for systematic prophylactic revision surgery is a question that arises regularly for malignant tumors, as it exposes to a high risk of facial palsy, while oncological benefits are unclear.

STUDY DESIGN

retrospective study.

SETTING

Multicentric.

SUBJECTS AND METHODS

We included all patients operated for systematic revision surgery in case of close margins after parotidectomy for a malignant tumor and analyzed the rate of tumor residue and its risk factors.

RESULTS

A tumor residue was identified in 43.5% of 23 cases, but none in case of initial complete excision with supra-millimetric margins. Invaded lymph nodes were identified in 6 cases, but none in case of low-grade tumors.

CONCLUSIONS

Systematic revision seems mandatory in case of infra-millimetric margins and high-grade tumors or positive lymph node; further studies are needed to confirm whether it can be spared for T1-T2/N0 low-grade tumors, with close margins but complete initial excision.

Facial Nerve Monitoring under Different Levels of Neuromuscular Blockade with Cisatracurium Besilate in Parotid Tumour Surgery

Background

Anaesthesia can alter neuronal excitability and vascular reactivity and ultimately lead to neurovascular coupling. Precise control of the skeletal muscle relaxant doses is the key in reducing anaesthetic damage.

Methods

A total of 102 patients with the normal functioning preoperative facial nerve who required parotid tumour resection were included in this study. Facial nerve monitoring was conducted intraoperatively. The surgeon stimulated the facial nerve at different myorelaxation intervals at TOF% (T4/T1) and T1% (T1/T0) and recorded the responses and the amplitude of electromyogram (EMG). Body movements (BM) or patient-ventilator asynchrony (PVA) was recorded intraoperatively.

Results

In parotid tumour resection, T1% should be maintained at a range of 30 to 60% while TOF% should be maintained at a range of 20 to 30%. Analysis of the decision tree model for facial nerve monitoring suggests a partial muscle relaxation level of 30% < T1% ≤ 50% and TOF ≤ 60%. A nomogram prediction model, while incorporating factors such as sex, age, BMI, TOF%, and T1%, was constructed to predict the risk of BM/PVA during surgery, showing good predictive performance.

Conclusions

This study revealed an adequate level of neuromuscular blockade in intraoperative parotid tumour resection while conducting facial nerve monitoring. A visual nomogram prediction model was constructed to guide anaesthetists in improving the anaesthetic plan.

[Surgical Management of Salivary Gland Carcinoma]

Salivary gland carcinomas are very threatening diseases. The patient's survival depends to a large extent on planning and performing the resection. This article provides assistance with the most important surgical decisions. Using illustrative examples and practical tips the article shows how oncological salivary gland surgery can be successful.

Intraoperative spinal accessory nerve monitoring in neck dissections

BACKGROUND

The identification and preservation of the spinal accessory nerve (SAN) is essential in neck surgeries due to possible complications. We report the technique to intraoperative neuromonitoring (IONM) of SAN in functional neck dissections.

METHOD

SAN was monitored by needle electrodes placed on the trapezius muscle. Preoperative and postoperative nerve mapping was performed.

CONCLUSION

IONM for spinal accessory nerve in patients undergoing neck dissection is a useful technique that can be valuable for neck surgeries where spinal nerve injury is at risk.

Long-Term Facial Nerve Outcome in Primary Parotid Cancer Surgery: A Population-Based Analysis

OBJECTIVES/HYPOTHESIS

To determine immediate postoperative and long-term facial nerve dysfunction after parotid cancer surgery, risk factors, and the role of facial reanimation surgery.

STUDY DESIGN

Population-based long-term analysis for all new primary parotid carcinoma cases in Thuringia from 1996 to 2019.

METHODS

Data of the cancer registries of Thuringia, a federal state in Germany, were analyzed in combination with hospital-based data on facial function.

RESULTS

About 477 patients (42.3% women; median age: 68 years) were included. It was observed that 6.7% had a preoperative facial nerve dysfunction, 11.7% received a radical parotidectomy, that is, that 5% had a normal preoperative facial function but needed radical surgery because of intraoperative detection of tumor infiltration into the facial nerve. About 10.2% received facial nerve reconstruction surgery. Immediate postoperative facial nerve dysfunction in the other patients was observed in 34.4% of the patients. Advanced T classification (odds ratio [OR] = 2.140; confidence interval [CI] = 1.268-3.611; P = .004) and neck dissection (OR = 2.012; CI = 1.027-3.940; P = .041) were independent risk factors for immediate postoperative facial nerve dysfunction. In addition, 22.0% showed no recovery during follow-up. Advanced T classification (OR = 2.177; CI = 1.147-4.133; P = .017) and postoperative radiotherapy (OR = 2.695; CI = 1.244-5.841; P = .012) were independent risk factors for permanent postoperative facial nerve dysfunction.

CONCLUSION

Patients with primary parotid cancer are at high risk for long-term facial nerve dysfunction. It seems that the possibilities of facial reanimation surgery needs to be utilized even more effectively.

LEVEL OF EVIDENCE

3 Laryngoscope, 2021.

Mucoepidermoid carcinoma of the parotid gland: Twenty-year experience in treatment and outcomes

BACKGROUND

Parotid gland mucoepidermoid carcinoma (MEC) has published five-year cancer-specific survival (CSS) rates of 77%-97%, with variance related to grade.

METHODS

Patients receiving primary surgery for parotid gland MEC from 1995 to 2014 at a tertiary medical center underwent clinical review, histopathologic review, and cytogenetic analysis. Survival outcomes were evaluated.

RESULTS

Among 58 patients, T/N/M classification was as follows: T1 in 35 patients, T2 in 14, T4a in 9, N0 in 53, N1 in 2, N2b in 3. Histologic grade was low in 27, intermediate in 17, and high in 12 patients with 98% MAML2 positivity. All patients underwent parotidectomy, and seven patients received adjuvant radiation therapy. CSS was 100% at 5 years and 94.1% at 10 and 15 years. Two patients experienced locoregional recurrence.

CONCLUSIONS

Treatment with adequate surgical resection and adjuvant radiation therapy for high-grade or advanced-stage tumors yields excellent survival, independent of clinical stage or pathologic grade.

The Experience of a Facial Nerve Unit in the Treatment of Patients With Facial Paralysis Following Skull Base Surgery

: The management of facial paralysis following skull base surgery is complex and requires multidisciplinary intervention. This review shows the experience of a facial nerve (FN) unit in a tertiary university referral center. A multidisciplinary approach has led to the breaking of some old treatment paradigms. An overview of five FN scenarios is presented. For each setting a contemporary approach is proposed in contrast to the established approach. 1) For patients with an anatomically preserved FN with no electrical response at the end of surgery for vestibular schwannoma, watchful waiting is usually advocated. In these cases, reinforcement with an interposed nerve graft is recommended. 2) In cases of epineural FN repair, with or without grafting, and a poor expected prognosis, an additional masseter-to-facial transfer is recommended. 3) FN transfer, mainly hypoglossal-to-facial and masseter-to facial, are usually chosen based on the surgeons' preference. The choice should be based on clinical factors. A combination of techniques improves the outcome in selected patients. 4) FN reconstruction following malignant tumors requires a combination of parotid and temporal bone surgery, involving different specialists. This collaboration is not always consistent. Exposure of the mastoid FN is recommended for lesions involving the stylomastoid foramen, as well as intraoperative FN reconstruction. 5) In patients with incomplete facial paralysis and a skull base tumor requiring additional surgery, consider an alternative reinnervation procedure, "take the FN out of the equation" before tumor resection. In summary, to achieve the best results in complex cases of facial paralysis, a multidisciplinary approach is recommended.

Management of a Buccal Space Mass: A Clinical Case Report

Background

Buccal space tumors constitute rare pathologies with significant histological diversity. They may pose serious diagnostic and therapeutic challenges for the head and neck surgeon.

Methods

A case of buccal space tumor diagnosed and treated in a tertiary center is presented. Clinical presentation, imaging, and surgical approach are discussed, followed by review of the literature.

Results

A 79-year-old male patient with a slowly growing painless mass on the right cheek presented to a head and neck reference center. Imaging revealed a tumor of the right buccal space with nonspecific characteristics. Imaging studies revealed extended infiltration of the masseter muscle as well as the anterior border of the parotid gland. FNA biopsy was performed but was nondiagnostic. The decision of surgical excision with a modified parotidectomy incision was taken. The lesion was completely excised with preservation of neighboring facial nerve branches and ipsilateral Stensen's duct. The postoperative course was uneventful. Histological examination showed CLL/Lymphoma, and the patient was referred to the hematology department for staging and further management.

Conclusion

Differential diagnosis of buccal space masses is very diverse. Despite challenges in the diagnostic and therapeutic approach, these entities may be managed surgically with minimal morbidity.

Reconstruction of Extensive Composite Parotid Region Oncologic Defects with Immediate Facial Nerve Reconstruction Using a Chimeric Scapulodorsal Vascularized Nerve Free Flap

BACKGROUND

 Cancer involving the parotid gland region may originates from parotid parenchyma itself or from locoregional organs and in rare cases, the facial nerve (FN) has to be sacrificed during tumor resection. In these cases, cancer extension often goes beyond the parotid compartment and requires extensive local resection responsible for complex multitissular defects. The goals of reconstruction may be summarized in the following two components: (1) restoration of the volumetric tissue defect and (2) FN reconstruction. The aim of this study is to describe our surgical technique and our cosmetic results using the chimeric scapulodorsal vascularized nerve (SDVN) flap to reconstruct extensive maxillofacial defects associated with FN sacrifice.

METHODS

 All patients undergone an extensive maxillofacial resection with FN sacrifice and primarily reconstructed with a SDVN flap were included. We classified the maxillofacial defects into six groups based on the type of resection. Intraoperative data including flap composition, topography of FN injury, length of nerve gap, and number of nervous anastomosis were recorded.

RESULTS

 Twenty-nine patients were included. Mean follow-up was 38.7 months. The harvested flaps included the SDVN combined with different components according to the defect group. A satisfactory volumetric restoration was obtained in 93% of cases. The mean number of distal nervous anastomosis was 4.5. The length of the vascularized grafted nerve ranged from 7 to 10 cm.

CONCLUSION

 This is largest series presented in literature on primary FN reconstruction utilizing a vascularized nerve graft. We believe that the chimeric SDVN flap should be highly considered for these cases due to its versatility. The surgeon is able to use single donor site available soft and hard tissues components along with a vascular motor nerve graft, which offers a great length and number of distal branches, and easily matches with the extracranial FN trunk and its peripheral ramifications.

Facial nerve management in patients with malignant skull base tumors

INTRODUCTION

The course of the facial nerve through the cerebellopontine angle, temporal bone, and parotid gland puts the nerve at risk in cases of malignancy. In contrast to Bell's palsy, which presents with acute facial paralysis, malignancies cause gradual or fluctuating weakness.

METHODS

We review malignancies affecting the facial nerve, including those involving the temporal bone, parotid gland, and cerebellopontine angle, in addition to metastatic disease. Intraoperative management of the facial nerve and long term management of facial palsy are reviewed.

RESULTS

Intraoperative management of the facial nerve in cases of skull base malignancy may involve extensive exposure, mobilization, or rerouting of the nerve. In cases of nerve sacrifice, primary neurorrhaphy or interposition grafting may be used. Cranial nerve substitution, gracilis free functional muscle transfer, and orthodromic temporalis tendon transfer are management options for long term facial paralysis.

CONCLUSION

Temporal bone, parotid gland, and cerebellopontine angle malignancies pose a tremendous risk to the facial nerve. When possible, the facial nerve is preserved. If the facial nerve is sacrificed, static and dynamic reanimation strategies are used to enhance facial function.

Immediate Intraoperative Repair of the Recurrent Laryngeal Nerve in Thyroid Surgery

OBJECTIVES

Recurrent laryngeal nerve (RLN) injury is a recognized risk during thyroid and parathyroid surgery and can result in significant morbidity. The aim of this review paper is to consider the optimal approach to the immediate intraoperative repair of the RLN during thyroid surgery.

METHODS

A PubMed literature search was performed from inception to June 2020 using the following search strategy: immediate repair or repair recurrent laryngeal nerve, repair or reinnervation recurrent laryngeal nerve and immediate neurorraphy or neurorraphy recurrent laryngeal nerve.

RESULTS

Methods of immediate intraoperative repair of the RLN include direct end-to-end anastomosis, free nerve graft anastomosis, ansa cervicalis to RLN anastomosis, vagus to RLN anastomosis, and primary interposition graft. Techniques of nerve repair include micro-suturing, use of fibrin glue, and nerve grafting. Direct micro-suture is preferable when the defect can be repaired without tension. Fibrin glue has also been proposed for nerve repair but has been criticized for its toxicity, excessive slow reabsorption, and the risk of inflammatory reaction in the peripheral tissues. When the proximal stump of the RLN cannot be used, grafting could be done using transverse cervical nerve, supraclavicular nerve, vagus nerve, or ansa cervicalis.

CONCLUSIONS

Current evidence is low-level; however, it suggests that when the RLN has been severed, avulsed, or sacrificed during thyroid surgery it should be repaired intraoperatively. The immediate repair has on balance more advantages than disadvantages and should be considered whenever possible. This should enable the maintenance of vocal cord tone, better and prompter voice recovery and avoidance of aspiration. Laryngoscope, 131:1429-1435, 2021.

Clinicopathologic Features and Survival Trends for Acinic Cell Carcinoma of the Major Salivary Glands: A Surveillance, Epidemiology, and End Results Population Analysis

Background

We analyzed a population-based national registry to identify the most influential patient pretreatment and treatment factors affecting overall survival (OS) and cause-specific survival (CSS) in patients diagnosed with acinic cell carcinoma (ACC) of the major salivary glands.

Methods

Using the Surveillance, Epidemiology, and End Results (SEER) database of the US National Cancer Institute (NCI) related to survival, a total of 1,254 patients with diagnosed ACC of the major salivary glands from 1975 to 2016 met inclusion criteria. Factors significant for OS and CSS were determined using univariate and multivariate analysis with the Cox proportional hazards model.

Results

Univariate OS analysis demonstrated that surgery favorably influenced longer survival compared to no surgery (hazard ratio (HR) 2.35, P < 0.05). Patient age was found to be highly predictive of superior OS (divided into 10-year age bands, P < 0.0001, younger age better). In multivariate OS analysis, there were statistically significant worse outcomes for men (HR 1.54, P < 0.05), grades III/IV (HR 2.5, P < 0.05), and distant disease (HR 3.55, P < 0.05) or regional disease (HR 1.22, P < 0.05). Patients diagnosed during years 1996 - 2016 had better OS when compared to earlier decades 1975 - 1995 (HR 1.38, P < 0.05). In univariate analysis, the mean CSS for grades I, II, and III/IV were 429 months (95% confidence interval (CI), ± 38.39), 426 months (95% CI, ± 25.73) and 198 months (95% CI, ± 66.38). Multivariate analysis of CSS further demonstrated that there were statistically significant worse outcomes for men (HR 1.68, P < 0.05), grade III/IV (HR 3.2, P < 0.05), tumor size greater than 40 mm (P < 0.001), and distant disease (HR 4.48, P < 0.05) or regional disease (HR 1.84, P < 0.05).

Conclusions

To our knowledge, this is the largest population-based study of OS and CSS of major salivary gland ACC. We found that the patient pretreatment and treatment factors including younger age at diagnosis, female sex, early stage, lower grade, surgical excision, and recent year of diagnosis are associated with improved survival in patients diagnosed with ACC of the major salivary glands. We hope that this information will aid in construction of further research projects that better refine optimal treatment protocol of individualized patient care.

Endoscopic versus conventional parotid gland excision: a systematic review and meta-analysis

The objective of this review was to conduct a systematic review and meta-analysis to compare endoscopic with conventional parotid tumour excision. Online databases including MEDLINE, EMBASE, EMCare, CINAHL, the Cochrane Central Register of Controlled Trials (CENTRAL), the World Health Organization International Clinical Trials Registry (ICTRP), and the ISRCTN registry were all searched. All randomised controlled trials and observational studies comparing endoscopic with conventional parotid tumour excision were included. Five studies were identified and analysis was reported in forest plots with 95% confidence intervals. Outcomes of interest included operating time, cosmesis, blood loss, facial nerve injury, Frey syndrome, duration of hospital stay, and tumour recurrence. Endoscopic tumour excision had a comparable operating time to conventional resection with an insignificant mean difference (p=0.08). Scar cosmesis in the endoscopic group was superior (mean difference: 2.95, p<0.05) and it also reported a lower volume of blood loss (mean difference: -31.84, p<0.05). No significant difference was found in the incidence of facial nerve injury or Frey syndrome between the two groups, but overall, fewer miscellaneous complications were observed in the endoscopic cohorts. Endoscopic parotid surgery reported a shorter duration of hospital stay, and tumour recurrence was similar in both treatment arms. Endoscopic parotid gland surgery is an effective alternative to conventional approaches with comparable operating times, reduced blood loss and fewer complications, as well as shorter inpatient stay and improved cosmesis. Further studies are, however, required with longer follow-up periods to assess outcomes between different subtypes of parotid tumour.

[Classification and surgical strategy of Work Ⅰ congenital first branchial cleft anomaly based on adjacent anatomy]

Objective:To explore the adjacent anatomic relationship and classification of Work Ⅰ congenital first branchial cleft anomaly（CFBCA） in order to guide clinical practice. Method:The data of 48 cases of Work Ⅰ CFBCA with complete data were analyzed retrospectively. Result:All 48 lesions were completely resected. 48 sides（100.0%） were anatomically preserved facial nerve, partial parotidectomy was performed on 33 sides（68.8%）, superficial lobe+deep lobe partial parotidectomy was performed on 9 sides（18.8%）, and 6 sides（12.5%） was not performed parotidectomy. External auditory canal reconstruction was performed on 32 sides（66.7%）; 43 sides（89.6%） underwent the anatomical preservation of the auricular lobe branch of the great auricular nerve; 9 sides（18.8%） was performed selective cervical lymphadenectomy at the same time. 45 sides of Work Ⅰ CFBCA presented irregular cystic or lobulated structure, the lesion was located below and behind the junction of the external auditory meatus bone and cartilage and distributed along the longitudinal axis of the external auditory canal; 3 sides were isolated in superficial lobe parenchyma of parotid gland. All lesions were located on the superficial surface of the main trunk and branches of the facial nerve. The average value of the shortest vertical distance between the lower edge of the lesion and the outlet of the main trunk of the facial nerve at the stylomastoid foramen was 7.2 （0-13.4 ）mm. Based on preoperative images and intraoperative findings, according to the adjacent relation with external auditory meatus , parotid gland and facial nerve, the classification of Work Ⅰ congenital first branchial cleft anomaly is proposed, which is specifically divided into 4 types: C1（posterior wall of the external auditory meatus） 17 cases（35.4%）, C2（inferior wall of the external auditory meatus） 13 cases（27.1%）, C3 （multi wall of the external auditory meatus） 15 cases（31.3%）, C4（isolated from parotid gland parenchyma） 3 cases（6.3%）. Conclusion:Work Ⅰ CFBCA has a close relationship with the adjacent anatomy of the region, and familiar with the classification of Work Ⅰ congenital first branchial cleft anomaly is helpful for the treatment of type and accurate resection.

The underappreciated role of auriculotemporal nerve involvement in local failure following parotidectomy for cancer

BACKGROUND

Locoregional recurrence rates following parotidectomy for cancer remain as high as 20-30%. The auriculotemporal nerve (ATN) may allow parotid cancers to spread from the facial nerve (FN) toward the skull base, causing local recurrence.

METHODS

Retrospective review of 173 parotidectomies for malignancy. Preoperative and post-recurrence imaging were reviewed by a neuroradiologist for signs of tumor adjacent to the ATN.

RESULTS

Clinical and imaging signs of possible ATN involvement correlated with FN weakness and sacrifice. Eight patients had pathologically confirmed tumor from the ATN or V3. Forty-four percent of local recurrences had post-recurrence imaging showing tumor along the course of the ATN. Locoregional failure along the ATN was also associated with preoperative FN weakness, intraoperative FN sacrifice, and failure to complete recommended adjuvant therapy.

CONCLUSIONS

Parotid cancers may invade the FN and spread to the skull base via the ATN. If not appropriately managed, this may lead to local recurrence.

Advances in facial nerve management in the head and neck cancer patient

PURPOSE OF REVIEW

The purpose of this review is to summarize best practices in facial nerve management for patients with head and neck cancer. In addition, we provide a review of recent literature on novel innovations and techniques in facial reanimation surgery.

RECENT FINDINGS

Although recommended when tumor ablation surgery requires facial nerve sacrifice, facial reanimation procedures are not always performed. Concurrent dynamic facial reanimation with masseteric nerve transfers and cable graft repair can preserve native facial muscle function. Static suspension can provide facial support and immediate resting symmetry for patients. Eyelid weight and eye care should not be delayed, particularly in patients with trigeminal sensory deficits. Choice of neural source to innervate a gracilis-free muscle transfer for smile reanimation remains controversial; however, new techniques, such as dual innervation and multivector muscle transfer, may improve aesthetic and functional outcomes.

SUMMARY

Management of the facial nerve in the setting of head and neck cancer presents unique challenges. When possible, simultaneous oncologic resection and facial reanimation is ideal given the open surgical field, newly dissected and electrically stimulatable facial nerve branches, as well as minimizing postoperative healing time to prevent postsurgical treatment delays. A coordinated approach to facial nerve management with a multidisciplinary surgical team may help provide optimal, comprehensive care.

Clinical-pathological prognostic factors and treatment failure patterns in T1-2 high-grade parotid gland cancer

OBJECTIVES

The purpose of this study was to evaluate the treatment outcomes of patients with T1-2, high-grade parotid cancer, and to analyze the prognostic factors and treatment failure patterns.

MATERIALS AND METHODS

Of the 101 patients who were diagnosed with high-grade parotid cancer from March 2003 to December 2018, a total of 39 males and 23 females who had T1-2 tumor were enrolled in this study.

RESULTS

The average follow-up period of patients in this study was 63.9 months. The 5-year overall survival rate was 73.0%, and the 5-year disease-free survival rate was 57.6%. Thirty-nine patients underwent less-than-total parotidectomies, and the remaining 23 patients underwent total parotidectomies. After surgery, 50 patients received adjuvant treatment. During the study, 25 recurrences were documented, including nine local recurrences and 16 distant metastases. The average time period between the end of initial treatment and disease relapse was 17.0 months. A total of 16 patients succumbed to disease progression. Multivariate Cox proportional regression analysis showed that lymphovascular invasion (LVI) was an independent prognostic factor affecting disease recurrence and patient deaths. Among various factors, LVI and lymph node (LN) metastasis showed statistically significant correlations with distant metastasis.

CONCLUSION

Although we achieved favorable therapeutic results using standard treatments in selected patients, T1-2 high-grade parotid cancers generally have poor prognosis. Distant metastases that occur during follow-up are a major factor in treatment failure and LVI and LN metastasis are significantly associated with distant metastasis.

Facial nerve electrodiagnostics for patients with facial palsy: a clinical practice guideline

PURPOSE

Facial nerve electrodiagnostics is a well-established and important tool for decision making in patients with facial nerve diseases. Nevertheless, many otorhinolaryngologist-head and neck surgeons do not routinely use facial nerve electrodiagnostics. This may be due to a current lack of agreement on methodology, interpretation, validity, and clinical application. Electrophysiological analyses of the facial nerve and the mimic muscles can assist in diagnosis, assess the lesion severity, and aid in decision making. With acute facial palsy, it is a valuable tool for predicting recovery.

METHODS

This paper presents a guideline prepared by members of the International Head and Neck Scientific Group and of the Multidisciplinary Salivary Gland Society for use in cases of peripheral facial nerve disorders based on a systematic literature search.

RESULTS

Required equipment, practical implementation, and interpretation of the results of facial nerve electrodiagnostics are presented.

CONCLUSION

The aim of this guideline is to inform all involved parties (i.e. otorhinolaryngologist-head and neck surgeons and other medical specialists, therapeutic professionals and the affected persons) and to provide practical recommendations for the diagnostic use of facial nerve electrodiagnostics.

Primary parotid lymphoepithelial carcinoma: A case report and literature review of a rare pathological entity

•

A high index of suspicion is required for primary parotid lymphoepithelial cancer in Caucasians with a pre-auricular mass.

•

LEC can afflict patients of any ethnicity in Epstein-Barr Virus non-endemic areas.

•

LEC of the parotid gland is a rare entity that requires complete surgical resection and post-operative radiation therapy.

Background

Lymphoepithelial carcinoma (LEC) of the salivary glands is a rare, but distinct, poorly-differentiated neoplasm that resembles undifferentiated nasopharyngeal carcinomas (NPC). Among primary salivary gland LECs, they most commonly arise in the parotid gland. These lesions have a noticeable racial predilection, mostly occurring in Asians and Arctic region native populations. They are strongly associated with Epstein-Barr virus (EBV), and are more common in EBV-endemic areas. The most common presenting symptoms of primary parotid LEC are parotid mass development and cervical lymphadenopathy. We report an unusual case of EBV-negative LEC in a Canadian Caucasian woman.

Case presentation

A 40-year-old female from Atlantic Canada presented with a rapidly enlarging preauricular mass and cervical lymphadenopathy. Preoperative diagnostics via radiology and fine needle aspiration alluded to an ambiguous primary parotid malignancy. She underwent a total parotidectomy with facial nerve sacrifice and ipsilateral selective neck dissection. The facial nerve was reconstructed with a lateral antecubital nerve graft. Pathology came back positive for LEC, and she began adjuvant radiotherapy. At her 1-year follow up, she was disease-free and obtained a House-Brackmann facial nerve function grade of 3.

Conclusions

The case report highlights the importance of having a high index of suspicion and the need for interdisciplinary collaboration in reaching the diagnosis of primary parotid LEC. LEC can afflict patients of any ethnicity in non-EBV endemic areas and should therefore be considered in all patients with a painless parotid mass regardless of ethnicity. Further studies are required to elucidate the oncogenic role of EBV in these cancers.

Facial nerve neurorrhaphy due to unexpected facial nerve injury during parotid gland tumor surgery

BACKGROUND

Unexpected facial nerve damage can occur during parotid gland tumor surgery. We sought to determine the incidence and treatment outcomes of unexpected facial nerve injuries in patients with parotid gland tumor surgery.

METHODS

We retrospectively enrolled in this study five patients, who underwent facial nerve neurorrhaphy due to unexpected facial nerve injury during parotid gland tumor surgery January 2012-August 2019.

RESULTS

There were five patients (0.008%) with unexpected facial nerve injuries during the parotid gland tumor surgery of 577 patients in our hospital for approximately 8 years. The most common injury site of facial nerve was the marginal mandibular branch (n = 3), followed by the buccal branch (n = 1), and the cervicofacial division (n = 1). In the case of unexpected facial nerve damage, our treatment is immediate primary neurorrhaphy and steroid treatment. Three patients of five recovered and two did not worsen immediately after surgery.

CONCLUSION

Unexpected facial nerve injury during parotid gland tumor surgery is extremely unfortunate. In this case, immediate primary neurorrhaphy and systemic steroids are recommended to restore facial function and reduce cosmetic deficits.

Dual Coaptation of Facial Nerve Using Masseteric Branch of Trigeminal Nerve for Iatrogenic Facial Palsy: Preliminary Reports

OBJECTIVES

Immediate facial nerve substitution or graft technique has been used for the repair of facial nerve defects occurring as a result of tumour dissection. However, some patients report unsatisfactory outcomes, such as difficulty in maintaining resting or smiling symmetry, due to persistent flaccid facial palsy. Here we evaluated the functional outcomes of transferring the masseteric branch of the trigeminal nerve to the facial nerve adjunct to facial nerve graft.

METHODS

We reviewed the medical records of seven patients who underwent facial reanimation surgery between 2014 and 2016. The patients were divided into two groups according to the type of facial reanimation surgery: group A, masseteric nerve innervation with interposition graft; group B, interposition graft only. The postoperative resting symmetry and dynamic movement were compared.

RESULTS

Facial contraction was first observed in group A at 4 months and in group B at 7.3 months. Most of the patients achieved reliable resting symmetry; however, one patient in group B exhibited unsatisfactory facial weakness on the affected side. Group A patients showed better dynamic movement than group B patients. Eye closure, oral excursion and oral continence were better in group A than in group B patients. Smile symmetry in both groups was similar due to hyperkinetic movement in group A patients and flaccidity in group B patients.

CONCLUSIONS

Dual innervation of the masseteric branch of the trigeminal nerve improves the dynamic movement of paralysed facial muscles and shortens the recovery period in patients with iatrogenic facial palsy.

A nomogram to estimate the risk of developing distant metastases in parotid cancer

BACKGROUND

Parotid cancer (PC) is a heterogeneous group of malignant tumors whose management mainly focuses on locoregional control. However, distant metastases (DM) can represent the most common cause of treatment failure. We have defined the predictors and developed a model that can predict a single patient's risk to develop DM.

METHODS

We have analyzed our institutional database of 259 patients with PC and use it to develop a nomogram. C-index and calibration curves were used to assess performance of our model.

RESULTS

DM appeared in 18.9% of patients. Age, cT, pN, perineural invasion, and adenoid cystic carcinoma were significantly associated with distant failure.

CONCLUSIONS

We here present the first model to identify patients with PC at high risk of DM. Such tool can be of great value in managing these rare cancers in terms of a more precise prognosis and follow-up while waiting for better systemic therapies to come in the future.

Altered facial muscle innervation pattern in patients with postparetic facial synkinesis

OBJECTIVES/HYPOTHESIS

Using surface electrostimulation, we aimed to use facial nerve mapping (FNM) in healthy subjects and patients with postparetic facial synkinesis (PPFS) to define functional facial target regions that can be stimulated selectively.

STUDY DESIGN

Single-center prospective cohort study.

METHODS

FNM was performed bilaterally in 20 healthy subjects and 20 patients with PPFS. Single-pulse surface FNM started at the main trunk of the facial nerve and followed the peripheral branches in a distal direction. Stimulation started with 0.1 mA and increased in 0.1 mA increments. The procedure was simultaneously video recorded and evaluated offline.

RESULTS

A total of 1,873 spots were stimulated, and 1,875 facial movements were evaluated. The stimulation threshold was higher on the PPFS side (average = 9.8 ± 1.0 mA) compared to the contralateral side (4.1 ± 0.8 mA) for all stimulation sites or compared to healthy subjects (4.1 ± 0.5 mA; all P < .01). In healthy subjects, selective electrostimulation ± one unintended coactivation was possible at all sites in >80% of cases, with the exception of pulling up the corner of the mouth (65%-75%). On the PPFS side, stimulation was possible for puckering lips movements in 60%/75% (selective stimulation ± one coactivation, respectively), blinking in 55%/80%, pulling up the corner of the mouth in 50%/85%, brow raising in 5%/85, and raising the chin in 0%/35% of patients, respectively.

CONCLUSIONS

FNM mapping for surgical planning and selective electrostimulation of functional facial regions is possible even in patients with PPFS. FNM may be a tool for patient-specific evaluation and placement of electrodes to stimulate the correct nerve branches in future bionic devices (e.g., for a bionic eye blink).

LEVEL OF EVIDENCE

2b Laryngoscope, 130:E320-E326, 2020.