The Correlation of Thyroid Hormone Levels and Anti-Thyroidal Drugs on Thyroid Size, Weight, and Ease of Surgical Dissection for Thyroidectomy for Graves' Disease.

Abstract

Patients with Graves' Disease often have a larger thyroid size than patients without thyroid disease. These patients also have elevated T3 and T4 with decreased TSH. We evaluate whether these thyroid labs, the use of antithyroid agents, or the size of a thyroid on ultrasound, correlate with the pathological size of a thyroid in patients who undergo total thyroidectomy for Graves' Disease. We further determine whether these parameters affect perioperative complications. A retrospective review of patients undergoing total thyroidectomy for Graves' Disease was performed from January 2004 to December 2016 in a single institution. 392 patients were included in the study. Univariate analyses were performed to compare thyroid size on US and pathology as well as weight to preoperative thyroid hormone values and medical comorbidities. Spearman rank correlation and ANOVA were used to identify factors associated with thyroid weight, total pathology size, and differences in size. Multivariate analysis was also performed to evaluate for correlation between thyroid function and perioperative complications. We found that elevated pre-operative T3 levels were associated with larger pathologic size (P = .027) and a greater difference in pathology vs. US thyroid volumes (P = .005), but not increased thyroid weight (P = .286). No significant differences were found for thyroid weight, pathology size, or difference in size for TSH, T4, or any specific preoperative ATD given. Only postoperative calcium levels were found to be statistically significant for TSH < 0.27 (P = .024) for peri-operative complications. These findings may allow for more accurate preoperative planning and intraoperative expectations in patients with Graves' Disease.