Arytenoid Fixation - Causes, Types, Symptoms, Diagnosis, and Treatment

Introduction

Arytenoid cartilage is three-sided pyramid-shaped cartilage present in the voicebox (larynx). Vocal folds are the bands of tissue that vibrate to produce sound, close while swallowing, and open while breathing. The arytenoid cartilage is attached to the vocal folds and helps the vocal folds to open, close, and relax while different functions. Arytenoid fixation causes immobility of both the vocal folds that can disrupt the normal functioning of the vocal folds like swallowing, talking and breathing. Arytenoid fixation occurs due to paralysis of the recurrent laryngeal nerve (nerve supply to the larynx).

What Is the Cause of Arytenoid Fixation?

Arytenoid cartilage fixation can occur due to the following:

• Trauma During Surgery: Longer intubation (tube placed in the throat while surgery for airway) period for past surgeries.

• Nerve Paralysis: Recurrent laryngeal nerve paralysis due to vocal fold trauma.

• Laryngeal Cancers: Arytenoid cartilage fixation can occur due to cancer of the voice box (larynx).

• Bone and Joint Disorders: Like rheumatoid arthritis (an autoimmune disease where the body attacks its joint tissues) involving the voice box (larynx) leads to vocal fold or arytenoid cartilage fixation.

• Direct Trauma to the Vocal Cords: Trauma to the vocal folds resulting in bilateral recurrent laryngeal nerve paralysis.

• Nerve Disorders: Like amyotrophic lateral sclerosis (central nervous system disorder affecting nerve cells in the brain and spinal cord that controls the body).

• Radiation Therapy: Patients after radiotherapy for laryngeal cancer also develop vocal cord immobility due to arytenoid fixation.

What Are the Signs and Symptoms of Arytenoid Fixation?

Signs and symptoms associated with arytenoid fixation are:

• Stridor (high-pitched whistling sound while breathing).

• Dyspnea (shortness of breath).

• Dysphonia (abnormal voice).

• Difficulty in breathing.

• Difficulty in swallowing.

What Are the Different Patterns of Arytenoid Fixation Seen in Laryngeal Cancers?

There are four different patterns of cricoarytenoid joint fixation based on the tumor involvement:

• Type 1: Cancer mass encapsulating the cricoarytenoid (cartilage present in voicebox) from above. The weight of the tumor mass results in the fixation of the arytenoid from the upper end without the actual involvement of the cricoarytenoid unit (CAU). It is seen in the case of supraglottic cancer (cancer involving the upper part of the larynx).

• Type 2: It is seen in the case of glottic cancer (cancer involving actual vocal fold muscles). It involves superior (upper) and inferior (lower) paraglottic space (connective tissue chamber of the voice box or larynx).

• Type 3: Tumor mass involves cricoarytenoid joint (CAJ- cartilage joint present in voice box)) by wrapping around it. It involves thyroarytenoid muscles (broad muscles that form the body of the vocal folds).

• Type 4: Tumor mass completely involves the cricoarytenoid joint extending to the hypopharyngeal submucosa (lower part of the throat).

How To Diagnose Arytenoid Cartilage Fixation?

• History: Complete history of the patient for the symptoms present; any recent trauma or previous voice box surgery is recorded.

• Computed Tomography (CT) Scans: This scan for the larynx is performed to check the size and extent of the involvement of the tumor mass. It also helps to identify any structural abnormalities related to the vocal folds (vocal cords).

• Magnetic Resonance Imaging (MRI): It is done to check the involvement of the cartilaginous framework of the voice box by the tumor along with the involvement of the paraglottic spaces (connective tissue chamber of the voice box or larynx).

• Laryngeal Electromyography: It is done to check the movement of the larynx and vocal folds and rule out any nerve disorders of the larynx like paralysis of recurrent laryngeal nerve. It records the nerve signals generated by the movement of muscles of the larynx during contraction and relaxation.

• Fiberoptic Laryngoscopy: A fiberoptic laryngoscope (a thin tube with attached light and camera) is used by an ENT (ear, nose, and throat) surgeon to evaluate the movement of the vocal folds with breathing in and out. It helps to detect any vocal fold immobility present.

How To Manage Arytenoid Fixation?

• Arytenoidectomy: Arytenoidectomy (widening of the larynx or voice box by removing the arytenoids cartilage surgically) surgery can be done by endoscopic (a thin tube with attached light and camera which helps to view the body's internal structures) approach with the lasers or can be performed by open surgical approach under direct vision. It is done under general or local anesthesia. In this surgery, the laryngeal inlet (opening) is widened surgically to increase the airway for breathing. Arytenoidectomy (removal of arytenoid cartilage) can be partial or complete depending on the involvement of the arytenoid cartilage fixation.

• Micro Trapdoor Flap Technique: It is one of the surgical methods used to treat narrowing of the laryngeal or tracheal space (laryngeal or tracheal stenosis) caused by the arytenoid cartilage fixation (due to trauma to the voice box causing scarring) with conservation of the arytenoid cartilage to a certain extent. In this method, a cut is given by the laser on the upper part of the trachea (windpipe). Vaporization (cutting and removing) of the scar below the mucosal tissue is done, and a micro trapdoor flap (small tissue flap) is raised and placed over the region from where the scar was removed to cover the raw surface. This method improves the airway by treatment of tracheal or laryngeal stenosis (narrowing of the trachea or larynx) by widening the tracheal and laryngeal openings surgically.

• Neck Dissection: In cases of laryngeal (voicebox) cancer, neck dissection is done to remove the involved lymph nodes of the neck. Radiation therapy is recommended for cancer patients after surgery to prevent the recurrence of cancer.

Conclusion

Arytenoid fixation can cause immobility of the vocal folds resulting in problems like swallowing, breathing, and talking. Arytenoid cartilage fixation can occur by the trauma to the voice box during the surgery leading to a scar that further causes narrowing of the upper airway. Recurrent nerve paralysis, arthritis of the larynx, and cancer of the larynx are other causes that lead to the fixation of the arytenoid cartilage, thereby restricting vocal cord mobility. Although there are various surgical techniques available to treat vocal cords immobility due to arenoid fixation, further research is needed for the newer surgical techniques that have limited complications after the surgery and a more conservative approach to prevent complete removal of the arytenoid cartilage. Early and prompt diagnosis and management of the arytenoid fixation are crucial to prevent the worsening of the symptoms.