Surgical outcome after thyroidectomy due to Graves' disease and Lugol iodine treatment: a retrospective register-based cohort study.

ABSTRACT

PURPOSE: This study aimed to investigate the relationship between Lugol iodine treatment in a rescue setting and surgical outcomes in Graves' disease patients. METHODS: The retrospective register-based cohort study included 813 patients who had undergone primary total thyroidectomy with a primary diagnosis of Graves' disease (ICD-code E05.0) at Karolinska University Hospital in Stockholm, Sweden, between January 2008 and December 2015. Of 813 patients, 33 (4.1%) were given Lugol iodine before surgery and the remaining, the non-Lugol group, did not. The study's primary outcomes were post-operative calcium treatment day 1, calcium and vitamin D supplements at discharge and follow-up. Secondary outcomes were laryngeal nerve damage and bleeding (defined as re-operation). RESULTS: Differences were found between the Lugol and non-Lugol groups in the treatment of calcium day 1 (45.5% vs 26.7%, p = 0.018), at discharge (36.4% vs. 16.2%, p = 0.002) and vitamin D supplements at discharge (36.4% vs. 19.1%, p = 0.015) as surrogate variables for hypocalcemia post-operatively. No differences could be seen at 4-6 weeks and six-months follow-up. There were no differences between the Lugol and non-Lugol groups in terms of operation time, laryngeal nerve damage, and bleeding. CONCLUSION: Patients in our cohort undergoing thyroidectomy due to Graves' disease pre-operatively treated with Lugol iodine as a rescue therapy had a higher risk of experiencing short term post-operative hypocalcemia.