Surgical Treatments for Glottal Insufficiency
The most common causes of glottal insufficiency are vocal fold paralysis, paresis (partial paralysis), and presbylaryngis (age related structural changes).
Several surgical treatment options are available. All involve crowding the vocal folds together by placing a material lateral to the vocal fold in an attempt to improve vocal closure and increase tone. Each method has advantages and disadvantages and will be outlined below.
A procedure done in the operating room with the patient awake but relaxed (sedated). A small incision (3 to 5cm) is made in the neck along a preexisting cosmetic skin crease. The thyroid cartilage is identified and a small window (3-5 mm) of cartilage lateral to the thyroarytenoid muscle is removed.
An implant is then carefully placed into the window to medialize the vocal folds and improve closure. Materials frequently used include Gore Tex and silastic. The surgeon typically evaluates vocal fold closure during the procedure via fiberoptic laryngoscopy. The patient usually spends the evening in the hospital and goes home the next morning. There is usually no need for voice rest, although voice conservation is often necessary. Advantages of the procedure include the ability to fine-tune the voice with the patient awake, no need for general anesthesia, permanent improvement, reversibility, and excellent results even with large glottal gaps. Disadvantages include a neck incision and the need for the patient to be awake and cooperative during the procedure. The procedure is also technically more difficult to perform than some of the other augmentation procedures.
Autologous fat augmentation of the vocal folds is done with the patient asleep under general anesthesia. A small (1 cm) incision is made in the periumbilical region of the stomach and approximately 15 cc of fat is harvested. This procedure is performed nearly identical to a cosmetic liposuction. After the fat is obtained, the patient’s larynx is brought into view with a laryngoscope under microscopic visualization. The fat is then injected lateral to the thyroarytenoid muscle and the vocal folds are medialized. Please click on this text to view an endoscopic fat injection (4MB). Notice how the slightly atrophic vocal folds are plump and fully medialized after the injection.
The advantages of fat injection are that the procedure is technically straightforward and easily performed. Vocal fold mass is enhanced and vocal quality is improved in the majority of patients. The procedure is performed with the patient asleep and requires no cooperation on the patient’s part. The primary disadvantage of fat injection is that it is difficult to predict how much of the fat will be reabsorbed by the body. Research suggests that anywhere from 30 to 60% will be reabsorbed. Thus, the surgeon must over-inject the fat by at least 30%. This results in a brief period of dysphonia until the excess fat is reabsorbed. In addition, excellent initial results may diminish over time if too much fat is reabsorbed by the body. It is also difficult to correct large gaps (>2 mm) with fat augmentation. Gaps greater than 2 mm are more successfully treated with laryngoplasty. Other disadvantages include the need for general anesthesia as well as a small incision on the stomach.
Intraoperative Collagen Injection
Human acellular dermis is now available for injection into the vocal fold. The material is readily obtained and has no antigenic (allergic) potential or risk of infectious disease acquisition. The procedure is done with the patient asleep under general anesthesia. There is no need for fat harvest. The patient’s larynx is brought into view with a laryngoscope under microscopic visualization. The collagen is then injected lateral to the thyroarytenoid muscle and the vocal folds are medialized. Initial results with this new form of collagen have been very promising. The advantages are that the procedure is very easy to perform, the collagen can be precisely placed in optimal position under microscopic visualization, and no skin incision is necessary. The disadvantages are that a general anesthesia is required, it is difficult to correct large gaps (>2 mm), and we are currently unsure how much long term reabsorption of the material will take place. Further investigation is necessary to evaluate its long-term efficacy.
In-office Collagen Injection
Collagen can also be injected into the vocal fold in the office without general anesthesia. The injection can be performed through the mouth with an elongated syringe or through a percutaneous injection. The procedure is performed under fiberoptic guidance to ensure adequate localization of the injection. The advantage of the in-office injection is that it can be performed safely and easily during a routine office visit. The procedure takes approximately 15 minutes and the patient goes home directly afterward. The disadvantage is that it is technically more difficult to perform than injection under the microscope in the operating room. Precise injections can be obtained in motivated patients, however. Similar to injection performed in the operating room, it is difficult to correct large gaps (>2 mm), and we are currently unsure how much long term reabsorption of the material will take place.
Autologous human fascia can also be injected similar to the technique of fat augmentation. Instead of harvesting fat, however, a small incision is made over the lateral thigh and fascia is obtained. Although controversial, the main advantage to fascia over collagen and fat is that there appears to be significantly less reabsorption, thus providing longer treatment success. The disadvantages to fascia are an incision on the lateral thigh, which may be associated with mild to moderate discomfort, resorption of the fascia, and the need for a general anesthetic.