IONM for Thyroid Surgery

The thyroid gland is an endocrine gland and responsible for production and regulation of various hormones. Due to lifestyle, environment or just by chance, undesired alterations can occur and lead to malfunction. In some cases, a surgical removal of the thyroid is inevitable. During this procedure surrounding nerves are endangered, since especially the recurrent laryngeal nerve and the superior laryngeal nerve run very close to the operation field. Both are responsible for movement of the vocal cords and their injury can cause problems with the pitch of the voice, hoarseness and even breathing.

IONM for thyroid surgery offers intermediate as well as continuous stimulation of the endangered nerves. Both are based on the EMG and the innervated muscles are the vocal cords. They can be monitored with intubation tubes covered with recording electrodes

The intermittent electrical stimulation helps the surgeon to find and to preserve the recurrent laryngeal nerve. Direct stimulation of the recurrent laryngeal nerve and its prior nerve, the vagal nerve, are a common standard procedure and the EMG signals before and after the thyroid resection are reviewed.

Additionally, continuous stimulation can be used to trigger and record the EMG signal throughout the procedure. An electrode especially designed for this purpose is attached to the vagal nerve and stimulates it continuously. By setting a baseline before resection, the changes in amplitude and latency can be calculated automatically during the whole procedure. Thus, nerve irritations can be detected within seconds and countermeasures can be initiated