Medical Edge Newspaper Column

When Vocal Cord Paralysis Affects Speaking, Breathing

August 12, 2007
Dear Mayo Clinic:
How can bilateral paralysis of the vocal cords be treated? -- Windsor, Ontario

Answer:
The vocal cords are basically two folds of tissue composed of muscle in the front and cartilage in the back. They are positioned side by side at the top of the airway in the voice box (larynx). The vocal cords open to enable us to breathe easily, and close to allow us to speak or sing. They also close when we eat or drink, to prevent solids or liquids from getting into our airway.

The vocal cords are activated by signals from the recurrent laryngeal nerves. In bilateral paralysis, the signal to both vocal cords has been interrupted. Common symptoms of this interruption include changes in the voice, choking or coughing while swallowing, and, most important, airway obstruction with shortness of breath.

Vocal cord paralysis can result from neck or chest injury, stroke, tumors, inflammation of the laryngeal nerves, and some neurological conditions such as polio. However, surgery on or near the neck or upper chest is the most common cause of bilateral paralysis, with the vast majority of operations involving the thyroid gland. The nerves that control the movements of the vocal cords lie close to the thyroid gland and they can be injured during thyroid surgery.

Generally, we treat bilateral vocal cord paralysis by addressing the airway and swallowing problems associated with the condition. If the vocal cords are immobilized in the closed position, the patient has trouble breathing, and a tracheotomy is performed. In this procedure, an incision is made in the front of the neck below the vocal cords and a breathing tube is inserted through a surgically created hole into the windpipe (trachea). The patient then breathes through the tube, bypassing the paralyzed vocal cords. The small tube may be fitted with a valve that opens for breathing and closes for talking.

Other common surgical options for treating bilateral vocal cord paralysis are designed to make the space between the cords wide enough to permit breathing but narrow enough so that exhaled air can vibrate the vocal cord tissue and allow patients to have a voice. These options, briefly described below, are not listed in any particular order because the best treatment for each patient is determined in large part by the condition of the larynx after paralysis.

Total arytenoidectomy involves complete removal of the cartilage at the back of one vocal cord to create more space between the vocal cords for air to pass through. Although this operation severs the connection between the two parts of a vocal cord (cartilage and muscle), the remaining muscle usually scars enough to partially restore voice function.

Medial arytenoidectomy creates space for breathing in much the same way as the total option, except that only part of that cartilage is removed and the vocal cord muscle remains attached. This procedure, if feasible, is a surer way to preserve the voice while improving breathing.

Suture lateralization of the arytenoid cartilage involves repositioning tissue rather removing it. A suture is placed around one vocal cord, which is then pulled to the side to open up the airway.

Transverse cordotomy opens the airway by detaching one arytenoid cartilage from the vocal cord muscle and then partially removing muscle to further open the airway.

Lateral type 2 thyroplasty allows the vocal cord on one side to remain intact but it is stretched and pulled slightly to the side by modifying the thyroid cartilage surrounding the vocal cords. The stretching and the slight lateralization of one vocal cord can lead to easier breathing with voice preservation.

Each of these surgical options entails a trade-off between breathing and voice; maximizing one compromises the other. And because no two situations are the same, it is essential that doctor and patient work together to choose the most promising option.

-- Nicolas Maragos, M.D., Otorhinolaryngology, Mayo Clinic, Rochester, Minn.