Preoperative administration of excess iodide increases thyroid volume of patients with Graves' disease.
Preoperative excess iodide administration for patients with Graves' disease has been widely adopted by surgeons to perform surgery safely, because it decreases blood flow in the thyroid. However, surgeons often encounter the enlargement of thyroid volume after iodide administration, which makes surgery even more difficult. In this study, we retrospectively investigated the change in thyroid volume in Graves' disease that was evaluated on ultrasonography between before and after iodide administration. Eighty-nine patients who received iodide administered (KI(+) patients) and 24 in whom iodide was not administrated (KI(-) patients) before surgery for Graves' disease were enrolled in the study. The level of free T4 (FT4) significantly decreased and that of thyroid stimulating hormone (TSH) significantly increased after iodide administration. Average thyroid volume also significantly increased for KI(+) patients after iodide administration and 17% of these patients showed a 30% or more increase in thyroid volume. In KI(-) patients who were preoperatively treated only by anti-thyroid drugs, thyroid volume did not change before surgery. Preoperative TSH levels remained below measurement sensitivity in 37 of KI(+) patients, but the average thyroid volume also significantly increased after iodide administration. These findings suggest that thyroid volume in Graves' disease can increase with iodide administration not only due to TSH stimulation but also due to reasons other than TSH. Surgeons should be careful when preoperatively iodide administering to patients with Graves' disease, especially when the goiter is large.
Yabuta
Tomonori
T
Department of Surgery, Kuma Hospital, Kobe, Japan.
Ito
Yasuhiro
Y
Hirokawa
Mitsuyoshi
M
Fukushima
Mitsuhiro
M
Inoue
Hiroyuki
H
Tomoda
Chisato
C
Higashiyama
Takuya
T
Kihara
Minoru
M
Uruno
Takashi
T
Takamura
Yuuki
Y
Kobayashi
Kaoru
K
Miya
Akihiro
A
Matsuzuka
Fumio
F
Miyauchi
Akira
A
D000328:Adult; D005260:Female; D006111:Graves Disease / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008297:Male; D011193:Potassium Iodide / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D011300:Preoperative Care; D012189:Retrospective Studies; D013961:Thyroid Gland / Q000000981:diagnostic imaging* / Q000473:pathology*; D014463:Ultrasonography
D011193:Potassium Iodide