Doppler evaluation of intrathyroid arterial resistances during preoperative treatment with Lugol's iodide solution in patients with diffuse toxic goiter

Background: The aim of this study was to ascertain the utility of echo-Doppler in the analysis of the low resistance thyroid vascularization in diffuse toxic goiter (DTG), and the effectiveness of Lugol's solution (iodine-iodide solution) in patients undergoing thyroidectomy. Study Design: Twenty-five patients with diffuse toxic goiter were evaluated and compared with 19 normal subjects. Patients were treated with increasing doses of Lugol's solution 2% for 7 days until a total dose of 75 mg of iodine was given. Echo-Doppler was performed on the last day of treatment, 12 hours before operation. Results: Mean basal Doppler Resistance Index (RI) of intrathyroid arterial flow was significantly lower in patients with DTG compared with normal controls (0.4718 +/- 0.0625 versus 0.55 +/- 0.05, range: 0.472 to 0.643; p = 0.008). Moreover, the RI was significantly increased in patients with DTG after Lugol's solution (+16.46 +/- 10.22%, range: -2.59 to +39.97; p < 0.0005). Conclusions: Echo-Doppler RI allowed documenting lower arterial resistances within the thyroid gland in patients with DTG. The use of preoperative Lugol's solution therapy induces normalization of those changes for safer thyroidectomy. (J Am Coll Surg 2000;191:607-612. (C) 2000 by the American College of Surgeons).