BT injection and TA myectomy combination treatment for adductor spasmodic dysphonia.

Most cases of spasmodic dysphonia are of the adductor spasmodic dysphonia (AdSD) type, for which botulinum toxin injection therapy (BT therapy) is the first choice worldwide. In Japan, botulinum toxin has been approved as an additional insurance indication for this disease since 2018.

On the other hand, thyroarytenoid myectomy (TAM) performed under microscopic laryngeal surgery was first reported by our team in 1998. Subsequently, additional trials were conducted in Japan and overseas, and in 2008, Nakamura et al. reported the “Muta method”.

Both BT and TAM are performed based on the same concept, aiming to reduce the function of the causative muscle, the thyroarytenoid muscle. The difference between the two is that BT therapy has only a short-term effect but is reversible, while TAM is semipermanent but irreversible.

For the 25 patients with suspected AdSD who visited the Osaka Voice Center in 2018 or later, multiple BT treatments were first performed for diagnosis and treatment purposes, and 18 patients with stable results were considered as confirmed cases of AdSD patients. After that, TAM was performed when the patient desired a semi-permanent effect.

In this article, we present the details of 15 cases in which TAM was performed under this treatment plan and report on the usefulness of the “Muta method”.