Comparison of swallowing disorder following gasless transaxillary endoscopic thyroidectomy versus conventional open thyroidectomy.

Background: In conventional open thyroidectomy, it is necessary to create a sub-platysma muscle flap in front of the strap muscle to provide working space. Adhesion between the flap and the strap muscle can occur after the operation, disrupting strap muscle movement and causing a swallowing disorder. Gasless transaxillary endoscopic thyroidectomy approaches the thyroid through the posterior of the strap muscle and does not require a sub-platysma muscle flap. The present study compared flap/muscle adhesion and occurrence of swallowing disorder following gasless transaxillary endoscopic thyroidectomy versus conventional open thyroidectomy.

Methods: Patients (N = 47) receiving thyroidectomy at the Kangbuk Samsung Medical Center, Seoul, Korea, were divided into two groups: group O (24 patients) underwent conventional open thyroidectomy, and group E (23 patients) underwent gasless transaxillary endoscopic thyroidectomy. The subjective Swallowing Impairment Index (SIS)-6 was used to evaluate the degree of post-operative swallowing disorder. Video recordings of swallowing movement were used to determine the contraction/relaxation (CR) ratio and evaluate adhesion, pre-operation, 3 days post-operation, and 1 month post-operation. Barium videofluoroscopy was used to measure movement of the hyoid bone and strap muscle.

Results: Group O had significantly higher post-operative SIS-6 scores than group E (p < 0.027), indicating greater swallowing disorder. The CR ratio increased in group O after the operation and continued to increase during 1 month post-operation, but decreased in group E (p < 0.001). Videofluoroscopy showed that hyoid bone movement in group O decreased by 55.46 and 56.75% at 3 days and 1 month post-operation, respectively, while the corresponding decreases in group E were 84.04 and 83.69%.

Conclusions: Conventional open thyroidectomy allowed adhesion of the strap muscle and sub-platysma muscle flap, resulting in non-specific dysphagia. These complications did not occur following gasless transaxillary endoscopic thyroidectomy.