Aspiration Prevention Surgery: Clinical Factors Associated With Improvements in Oral Status Intake and Suction Frequency

Vocal Fold Motion Impairment in Neurodegenerative Diseases

Vocal fold motion impairment (VFMI) is the inappropriate movement of the vocal folds during respiration, leading to vocal fold adduction and/or abduction problems and causing respiratory and vocal impairments. Neurodegenerative diseases (NDDs) are a wide range of disorders characterized by progressive loss of neurons and deposition of altered proteins in the brain and peripheral organs. VFMI may be unrecognized in patients with NDDs. VFMI in NDDs is caused by the following: laryngeal muscle weakness due to muscular atrophy, caused by brainstem and motor neuron degeneration in amyotrophic lateral sclerosis; hyperactivity of laryngeal adductors in Parkinson's disease; and varying degrees of laryngeal adductor hypertonia and abductor paralysis in multiple system atrophy. Management of VFMI depends on whether there is a presence of glottic insufficiency or insufficient glottic opening with/without severe dysphagia. VFMI treatment options for glottic insufficiency range from surgical interventions, including injection laryngoplasty and medialization thyroplasty, to behavioral therapies; for insufficient glottic opening, various options are available based on the severity and underlying cause of the condition, including continuous positive airway pressure therapy, botulinum toxin injection, tracheostomy, vocal fold surgery, or a combination of interventions. In this review, we outline the mechanisms, clinical features, and management of VFMI in NDDs and provide a guide for physicians who may encounter these clinical features in their patients. NDDs are always progressive; hence, timely evaluation, proper diagnosis, and appropriate management of the patient will greatly affect their vocal, respiratory, and swallowing functions as well as their quality of life.

Management and Treatment for Dysphagia in Neurodegenerative Disorders

Patients with neurodegenerative disorders (NDDs) often experience functional dysphagia, which may involve dysfunction in a specific phase of swallowing or in the entire process. This review outlines the approach to dysphagia in the setting of NDDs. Distinguishing the etiology of dysphagia can be difficult, and it is important to always look out for signs pointing to NDD as the cause. Thorough diagnostic work-up is essential, and it includes a comprehensive history and physical examination, alongside swallowing function tests, such as fiberoptic endoscopic evaluation of swallowing, videofluoroscopic swallowing study, and high-resolution manometry. Management requires a multidisciplinary approach with a treatment plan tailored to each patient. This involves dietary guidance, swallowing rehabilitation, and surgery in cases in which improvement with rehabilitation is inadequate. Surgery may involve altering certain pharyngolaryngeal structures to facilitate swallowing and reduce the risk of aspiration (swallowing improvement surgery) or separating the airway and digestive tract while sacrificing laryngeal function, with the main goal of preventing aspiration (aspiration prevention surgery). Proper management stems from recognizing the impact of these disorders on swallowing and consistently finding ways to improve the quality of life of patients.

Aspiration prevention surgeries: a review

BACKGROUND

Severe dysphagia can cause intractable pneumonia and lead to life-threatening conditions. Intractable aspiration can occur despite medical management for aspiration prevention. Surgical intervention is indicated for intractable aspiration to prevent potentially life-threatening complications. Since the 1970s, several surgical treatments to prevent aspiration have been reported, and various aspiration prevention surgeries have been introduced, but little is known about them or their benefits. This is a review of the types of aspiration prevention surgery, with the aim of increasing aspiration prevention surgery awareness and their clinical outcomes among medical professionals, which will guide the choices of aspiration prevention surgeries for patients with intractable aspiration.

MAIN BODY

Aspiration prevention surgeries can be categorized into three according to their approaches: removal of the larynx, altering the structure of the trachea, and closure of the larynx. Aspiration prevention surgeries to remove the larynx include total and central-part laryngectomy. Aspiration prevention surgeries to alter the structure of the trachea include tracheoesophageal diversion, laryngotracheal separation, and the tracheal flap method. Surgeries to close the larynx can be divided into supraglottic laryngeal closure, glottic laryngeal closure, and subglottic laryngeal closure. Aspiration prevention surgeries prevent aspiration and increase oral intake in 50-80% of patients. Most patients lose vocal function after aspiration prevention surgeries; however, some patients who have undergone total laryngectomy or laryngotracheal separation restored their speech function through tracheoesophageal puncture and use of voice prosthesis. Postoperative suture failure is frequent after epiglottic flap closure and total laryngectomy but rare after central-part laryngectomy, laryngotracheal separation, glottic closure, and subglottic closure. Furthermore, aspiration prevention surgeries improve the quality of life of patients and their caregivers by decreasing suctioning frequency.

CONCLUSIONS

In this review, we described the history and development of aspiration prevention surgeries. Medical professionals need to continually improve their knowledge and skills to facilitate appropriate aspiration prevention surgeries according to patient condition.