The importance of pre- and postoperative laryngeal examination for thyroid surgery.

In this issue of Thyroid, Lee and colleagues, at Soonchunhyang University Bucheon Hospital, Korea, prospectively report on the effect of percutaneous injection of the vocalis muscle (injection thyroplasty) in a series of patients with transient and permanent vocal cord paralysis (VCP) after thyroidectomy (1). They attempted to medialize the paralyzed atrophic and lateralized vocalis muscle through this injection, allowing more normal glottic closure for improved speech and swallowing. In their study (1) they demonstrate injection thyroplasty to be a safe and simple transcutaneous procedure accomplished with a 25-gauge needle under local anesthesia. Less than 1 mL of either polyacrylamide hydrogel or hyaluronic acid was injected through the cricoid-thyroid membrane or thyroid cartilage while the patient was examined in the office with fiber optic laryngeal endoscopy. They measured a variety of acoustic, perceptual, stroboscopic, aerodynamic, and voice-related data and found that significant improvements in these measures were durable over their 6-month period, with some patients responding up to 2 years. They report no complications of airway obstruction, migration of the injected material, or granuloma formation. While this study (1) is a large series relating to VCP postthyroidectomy, the efficacy and safety of such injection are supported by the work of others (2–4). Such vocal cord injection can be done as a transcutaneous or transoral office procedure, typically without antibiotics or steroids. The patient is observed for about 15–20 minutes after the procedure and then maintains voice rest for a period of time. In recent years there has been a substantial expansion of such in-office procedures, including laser laryngeal treatment, Botox laryngeal injection, laryngeal biopsy, and transnasal esophagoscopy (5). In the past, injection of polytetrafluoroethylene (Teflon) fell from favor due to problems of migration and granulomatous reaction. Certainly other treatment options exist for repair of postoperative VCP, including formal open thyroplasty, which involves a cervical skin incision, partial thyroid cartilage removal, and placement of silastic implant or other spacer material lateral to the vocal cord. This procedure may be combined with arytenoid adduction whereby the arytenoid cartilage is repositioned through suture placement to modify the desired vector of force on the repositioned paralytic cord so as to optimize the voice. Simpler and less invasive injection thyroplasty may be less suitable for patients with large posterior glottic gaps and may be less durable. The simplicity, safety, and effectiveness of injection thyroplasty have resulted in recent gains in its popularity. Lee and colleagues’ work (1) emphasizes the importance of recognition and treatment of postoperative voice changes.