Doctoral defence: Linda Sõber “Impact of thyroid disease and surgery on patient’s quality of voice and swallowing”

On 31 March at 15:00 Linda Sõber will defend her doctoral thesis “Impact of thyroid disease and surgery on patient’s quality of voice and swallowing”.

Supervisors:
Professor Urmas Lepner, University of Tartu
Otorhinolaryngologist Priit Kasenõmm, Tartu University Hospital

Opponent: 
Associate Professor Ahmed Geneid, University of Helsinki (Finland)

Summary
Thyroid disorders are one of the most common endocrine disorders requiring surgical treatment. Voice and swallowing disturbances are well-known complications of both thyroid disease and surgery. Due to the close proximity of the laryngeal nerves, the most severe voice and swallowing problems are considered to be caused by postoperative nerve injury. However, other possible causes of voice and swallowing disturbances after thyroid surgery involve soft tissue edema, hematoma, localized neck pain, intubation tube induced tissue damage, laryngopharyngeal reflux disease etc. Previous studies have described alterations in voice and swallowing quality already in preoperative thyroid patients in up to 76% of cases.

The goal of the present PhD thesis was to evaluate pre- and postoperative voice and swallowing disorders in thyroid patients and to identify dynamic changes during postoperative period. Analysis revealed that changes in the laryngeal area caused by thyroid disorders do not impact patient’s voice but do cause marked disturbances in swallowing quality. In addition, we found a possible role of the enlarged gland in the aggravation of laryngopharyngeal reflux symptoms in thyroid patients. However, postoperatively we detected deterioration in voice and swallowing quality irrespective of laryngeal nerve injury. More profound impairment is observed in the patient group with permanent paralysis. Regardless of postoperative laryngeal nerve injury, both voice and swallowing quality recovered to preoperative values by the end of the follow-up period. Furthermore, in patients without laryngeal nerve injury, swallowing function improves following thyroid surgery. We found large thyroid mass to be a risk factor for postoperative laryngeal nerve injury. However, general anesthesia played no substantial role on postoperative voice and swallowing disturbances.