Salivary Gland Neoplasms

P. J. Bradley, D. W. Eisele

• Publisher: S. Karger
• Year: 2016
• ISBN:
  9783318058024
• Topic: Medicine
• Subtopic: Pathology

This volume in the book series 'Advances in Oto-Rhino-Laryngology' summarizes the current scientific knowledge of salivary gland neoplasms and illustrates recent advances in this clinical area. Chapters are authored by world renowned experts who cover the full breadth of salivary gland neoplasms, from benign to malignant, primary to secondary, and pediatric to adult. This comprehensive review highlights the outcome of treatments as well as the classification, diagnosis, and management of salivary gland neoplasms. It also includes commentary on the future perspective necessary for improvement. All clinicians, both surgical and non-surgical, involved in the diagnosis and treatment of patients with symptoms and diseases of the salivary gland, will find this book indispensable reading. It is also a beneficial educational resource for clinicians, students, and experts in the field.

Bradley PJ, Eisele DW (eds): Salivary Gland Neoplasms.
Adv Otorhinolaryngol. Basel, Karger, 2016, vol 78, pp 120-131 (DOI: 10.1159/000442132)

______________________

Facial Reconstruction and Rehabilitation

Orlando Guntinas-Lichius^a · Dane J. Genther^b · Patrick J. Byrne^{b, c}

^aDepartment of Otorhinolaryngology, Jena University Department, Jena, Germany; Departments of ^bOtolaryngology - Head and Neck Surgery and ^cDermatology, The Johns Hopkins University School of Medicine, Baltimore, Md., USA

______________________

Abstract

Extracranial infiltration of the facial nerve by salivary gland tumors is the most frequent cause of facial palsy secondary to malignancy. Nevertheless, facial palsy related to salivary gland cancer is uncommon. Therefore, reconstructive facial reanimation surgery is not a routine undertaking for most head and neck surgeons. The primary aims of facial reanimation are to restore tone, symmetry, and movement to the paralyzed face. Such restoration should improve the patient's objective motor function and subjective quality of life. The surgical procedures for facial reanimation rely heavily on long-established techniques, but many advances and improvements have been made in recent years. In the past, published experiences on strategies for optimizing functional outcomes in facial paralysis patients were primarily based on small case series and described a wide variety of surgical techniques. However, in the recent years, larger series have been published from high-volume centers with significant and specialized experience in surgical and nonsurgical reanimation of the paralyzed face that have informed modern treatment. This chapter reviews the most important diagnostic methods used for the evaluation of facial paralysis to optimize the planning of each individual's treatment and discusses surgical and nonsurgical techniques for facial rehabilitation based on the contemporary literature.

© 2016 S. Karger AG, Basel

Introduction

Facial paralysis is caused by a tumor invading the facial nerve along its course from the brainstem to the facial musculature and affects approximately 5% of patients with salivary gland tumors [1]. The most frequent etiology among this subset of patients is the topic of this chapter: extracranial infiltration of the facial nerve by a malignant parotid tumor. The incidence of facial palsy in individuals with parotid cancer at the time of presentation is 12-15% [2]. For resectable salivary gland cancer with preoperative paralysis, the treatment of choice is radical parotidectomy with resection of the involved segment of the facial nerve [3]. The degree to which the facial nerve is infiltrated varies from partial involvement of one branch to complete involvement of the main trunk. If feasible from a technical and oncologic standpoint, the facial nerve should be reconstructed immediately following tumor resection. Another, albeit less common scenario, is resection and reconstruction of the marginal mandibular branch in the case of submandibular gland cancer. Finally, patients treated for salivary gland cancer who have long-term facial palsy, either because primary nerve reconstruction was not performed following resection or because full recovery of postoperative palsy was expected but not realized, may desire secondary facial reanimation.

When confronted with facial weakness secondary to a salivary gland neoplasm that requires surgical correction, achievement of an optimal patient outcome requires experience in a variety of facial reanimation techniques [1, 4, 5]. The exact techniques and procedures to be employed depend on many factors, including the site of the lesion, extent of the current and/or expected palsy, viability of the proximal facial nerve stump, denervation time, and sensory function of the trigeminal nerve. Additionally, the surgeon must consider the patient's age, medical comorbidities, and wishes. Adept assessment of these factors allows for determination of an individualized approach to repair and reanimation. Fortunately, facial analysis and diagnostics have undergone some important advances in recent years with regard to the establishment of objective tools for the assessment of facial weakness that have largely replaced traditional subjective facial nerve grading [6, 7]. The goal of these objective tools is to more accurately and reliably evaluate facial nerve function prior to and after facial nerve reconstruction.

Preoperative Assessment

In accordance with oncologic principles, reconstruction of the facial nerve is subordinate to primary treatment of the salivary gland neoplasm. The goal of surgical reconstruction of the facial nerve is to restore function of the mimic musculature. Ideally, this includes reestablishment of the resting tone of all mimic muscles and restoration of frontal frowning with lifting of the eyebrows, closure of the eyes, symmetry of the nasolabial fold, and the ability to laugh symmetrically. Practically, restoration of eye closure and smile reanimation receive the highest priority in facial reanimation surgery [8]. During preoperative assessment, the evaluator must confirm the facial nerve lesion as the etiology of the facial palsy, confirm the irreversibility of the damage, and determine the exact extent of the lesion. The most useful diagnostic tools are the patient's history, clinical examination, electrodiagnostics, and in some cases, imaging. More recently, assessment of an individual patient's concerns using patient-reported outcome measures (PROMs) has gained increased attention [9].

Electrophysiological Profile

In contrast to acute facial palsy, electroneurography does not play a significant role in patients with a proven facial nerve lesion due to a salivary gland neoplasm; however, electromyography (EMG) does play a central role in the electrophysiological evaluation of such patients. Each facial muscle of interest and its related facial nerve branch can be assessed by EMG, establishing an individual electrophysiological profile [10]. Acute facial nerve damage due to a malignant tumor or due to tumor resection causes pathologic alterations in the innervation of target facial muscles [11]. Chronic facial nerve damage in long-term palsy leads to muscular atrophy, which can be demonstrated by alterations of the insertion potentials during needle EMG. EMG can be used to monitor the process of nerve regeneration after facial nerve reconstruction and precedes clinical regeneration [12]. Finally, EMG allows for quantification of the functional outcome after facial reanimation [13, 14], as well as quantification of defective healing, namely synkinesis and dyskinesis, after recovery is complete [12].

Imaging

Preoperative facial palsy from salivary gland cancer can be the result of tumor invasion or perineural spread. MRI is the method of choice for localization of the site of the lesion and for determination of the extent of perineural spread, providing useful information for determining appropriate surgical resection [15]. Additionally, MRI can be used to evaluate the degree of atrophy of the facial musculature in cases of long-term denervation and to monitor facial muscle growth after reinnervation following facial nerve surgery [16].

Recently, protocols have been established for standardized quantitative ultrasound investigations of most major facial muscles [17, 18]. This technology can be used for regional and quantitative evaluation of facial muscles in patients with facial palsy [19], and after facial nerve reconstruction, serial ultrasound examinations can be used to monitor regeneration of the facial muscles, ideally showing progressive facial muscle regrowth [20].

Evaluation of Facial Motor Function

Clinicians need a uniform, objective, accurate, reliable, simple, and sensitive facial grading system to characterize fa...

Table of contents

• Cover Page
• Front Matter
• Classification of Salivary Gland Neoplasms
• Frequency and Histopathology by Site, Major Pathologies, Symptoms and Signs of Salivary Gland Neoplasms
• Molecular Pathology and Biomarkers
• Evaluation: Imaging Studies
• Evaluation: Fine Needle Aspiration Cytology, Ultrasound-Guided Core Biopsy and Open Biopsy Techniques
• Facial Nerve Monitoring
• Surgery for Benign Salivary Neoplasms
• Recurrent Benign Salivary Gland Neoplasms
• Prognostic Scoring for Malignant Salivary Gland Neoplasms
• Surgery for Primary Malignant Parotid Neoplasms
• Metastatic Cancer to the Parotid
• Surgery for Malignant Submandibular Gland Neoplasms
• Surgery for Malignant Sublingual and Minor Salivary Gland Neoplasms
• Facial Reconstruction and Rehabilitation
• Management of Regional Metastases of Malignant Salivary Gland Neoplasms
• Indications for Salivary Gland Radiotherapy
• Chemotherapy and Targeted Therapy
• Management of Inoperable Malignant Neoplasms
• Management of Recurrent Malignant Salivary Neoplasms
• Salivary Gland Neoplasms in Children and Adolescents
• Distant Metastases and Palliative Care
• Quality of Life after Salivary Gland Surgery
• Salivary Gland Neoplasms: Future Perspectives
• Author Index
• Subject Index