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-Dopp ler in the analysis of the low resistance thyroid vascularization in diffus e toxic goiter (DTG), and the effectiveness of Lugol's solution (iodine-iod ide 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 increasin g doses of Lugol's solution 2% for 7 days until a total dose of 75 mg of io dine 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 cont rols (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 aft er 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 Lug ol's solution therapy induces normalization of those changes for safer thyr oidectomy. (J Am Coll Surg 2000;191:607-612. (C) 2000 by the American Colle ge of Surgeons).