Impact of potassium iodide on thyroidectomy for Graves' disease: Implications for safety and operative difficulty.

BACKGROUND: Potassium iodide often is prescribed prior to thyroidectomy for Graves' disease, but the effect of potassium iodide on the ease and safety of thyroidectomy for Graves' is largely unknown.

METHODS: We conducted a prospective, cohort study of patients with Graves' disease undergoing thyroidectomy. For the first 8 months, no patients received potassium iodide; for the next 8 months, potassium iodide was added to the preoperative protocol for all patients. Outcomes included operative difficulty (based on the Thyroidectomy Difficulty Scale) and complications.

RESULTS: We included a total of 31 patients in the no potassium iodide group and 28 in the potassium iodide group. According to the Thyroidectomy Difficulty Scale, gland vascularity decreased in the potassium iodide group (mean score 2.6 vs 3.3, P = .04), but there were no differences in friability, fibrosis, or size of the thyroid or in overall difficulty of operation (P = not significant for all). Despite similar operative difficulty, patients prescribed potassium iodide were less likely to experience transient hypoparathyroidism (7% vs 26%, P = .018) and transient hoarseness (0% vs 16%, P = .009) compared with the no potassium iodide group.

CONCLUSION: Potassium iodide administration decreases gland vascularity, but does not change the overall difficulty of thyroidectomy. Preoperative use of potassium iodide solution was, however, associated with less transient hypoparathyroidism and transient hoarseness, suggesting that potassium iodide improves the safety of thyroidectomy for Graves' disease.