Definition and Overview
Thyroplasty is a specialised procedure performed on the larynx for patients with vocal cord paralysis, a serious condition that occurs when there is an injury to the recurrent laryngeal nerve, which supplies the majority of the muscles of the larynx. Nerve injury can be due to a number of causes, the most common of which is surgery, typically of the thyroid gland. It can also be caused by tumors, radiation injury, and neck trauma, among others.
Who Should Undergo and Expected Results
The vocal cords can be found at the entrance of the trachea. In a normal person, the vocal cords are in an open position at rest to allow breathing. When speaking or making a sound, the vocal cords close off and vibrate. In cases of vocal cord paralysis, there is weakness or immobility of at least one vocal cord, resulting in hoarseness. The condition can also present with aspiration or choking, especially during intake of liquids. Other symptoms include ineffective coughing and even breathing problems. Treatment of vocal cord paralysis depends on the cause. Speech therapy, which includes special exercises, is the primary treatment. Vocal fold injections using fillers, such as fat or collagen, can be performed to add some bulk to the vocal cord. However, in cases wherein the vocal cord is completely paralysed, augmentation may be inadequate. For such cases, thyroplasty is considered.
How is the Procedure Performed?
Thyroplasty, also known as laryngeal framework surgery or medialisation laryngoplasty, is a surgical procedure performed for vocal cord paralysis. Instead of using an injectable filler to augment the vocal cords, thyroplasty makes use of an implant, which can be composed of one or several materials, such as silicone, polytetrafluoroethylene (Goretex), titanium, or the patient’s own cartilage.
A thyroplasty is a short procedure and commonly performed under a combination of local anesthesia and intravenous sedation, allowing the surgeon to check the patient’s voice during the procedure.
A small incision is made in the neck near the area of the larynx and part of the thyroid cartilage is removed to provide access to the vocal cords. The implant is positioned near the vocal cord, pushing the vocal cord as close to the middle section as possible. An implant is usually required on the side of the injury alone. However, in about a third of patients, an implant may also be needed on the opposite side to strengthen it.
In cases wherein an implant cannot fully correct the condition, an additional technique, called arytenoid adduction, can also be performed during the procedure. A suture may be placed through the arytenoid cartilage, allowing the vocal cord to move towards the center and restore the optimal tension on the affected vocal cord. Many surgeons believe that a combination of these two techniques yields the best results in terms of restoring voice quality.
Once the implant has been positioned properly, a fiber optic scope is inserted, allowing the surgeon to view the larynx and check the placement of the implant. The patient may be requested to speak during the laryngoscopy, allowing the surgeon to check the movement of the cords. The results of a thyroplasty are permanent but are reversible by the removal of the implant. In some cases, a second surgery may be necessary if the implants need to be repositioned. Patients are usually sent home a day after the procedure and are advised to avoid strenuous activities for about a week. Resting the voice is also advised and shouting and whispering should be avoided.
Possible Risks and Complications
Thyroplasty is generally a safe procedure, but complications can still occur. These include:
- Poor voice quality – This is a common complication that can be caused by the improper placement of the implant or using the wrong size of the implant.
- Perioperative edema - In some cases, the occurrence of perioperative edema produces good voice quality immediately after the surgery, which changes once the swelling subsides. Some surgeons give steroids preoperatively to minimize edema. In cases where poor voice quality occurs, a revision thyroplasty may have to be performed.
- Implant migration. This is not a common complication, but there have been reports of migration into the airway or through the neck.
- Airway difficulties - Because the surgery involves the larynx, airway difficulties can be a major concern. Swelling, edema and hematoma can cause partial obstruction, which is a serious condition. Use of steroids in both the preoperative and postoperative periods may help prevent this complication.
Carpes LF, Kozak FK, Leblanc JG, et al. Assessment of vocal fold mobility before and after cardiothoracic surgery in children. Arch Otolaryngol Head Neck Surg. 2011 Jun. 137(6):571-5.
Yung KC, Likhterov I, Courey MS. Effect of temporary vocal fold injection medialization on the rate of permanent medialization laryngoplasty in unilateral vocal fold paralysis patients. Laryngoscope. 2011 Jul 6.