Type II Thyroplasty: A Surgical Treatment for Adductor Spasmodic Dysphonia

Type II Thyroplasty is a surgical procedure that separates the vocal folds and it is used to treat the adductor form of spasmodic dysphonia. It is reasoned that speaking in those with AdSD is affected due to the tight closure of the vocal folds during speech. During the procedure, the surgeon physically separates the vocal folds to limit their ability to excessively contact one another. A titanium bridge is inserted to maintain the separation. The operation is typically performed under local anesthesia with sedation so that the patient can talk while the surgeon adjusts the vocal folds to the optimal distance. The result is a slightly weaker and breathier voice with improved fluency. Long term outcomes have not yet been published.

This procedure was developed by Dr. Isshiki and his group around 2000. The concept of this surgery is aiming to smooth the airflow by making the glottal gap wider during phonation. The titanium bridges used in this procedure are manufactured and approved for use in Japan only at the Isshiki Memorial Voice Center. They are not FDA approved and not yet available for use in the United States. The NSDA has been working with Nobel Pharma to bring these bridges to the US for a clinical trial for adductor spasmodic dysphonia.