Thyrotropin level and thyroid volume for prediction of hypothyroidism following hemithyroidectomy in an Asian patient cohort.
BACKGROUND
As more patients undergo diagnostic thyroid surgery, the development of posthemithyroidectomy hypothyroidism is becoming a major concern. We hypothesized that the preoperative thyrotropin (thyroid-stimulating hormone, TSH) level and ultrasonographically measured thyroid volume, both commonly available in thyroid nodule patients, may predict the development of posthemithyroidectomy hypothyroidism.


METHODS
Among the 132 patients who underwent hemithyroidectomy from January 2004 to January 2006, a total of 101 patients who were followed for more than a year were included in the analysis.


RESULTS
Biochemical hypothyroidism developed in 37 patients (36.6%). Patients who developed postoperative hypothyroidism showed higher TSH levels (P < 0.001) and smaller remnant thyroid volumes (P = 0.014). Logistic regression analysis showed that the TSH level and remnant thyroid volume were independent predictors of posthemithyroidectomy hypothyroidism (P < 0.001 and P = 0.04, respectively). A risk scoring system using these two factors was created based on the results of logistic regression analyses. The incidences of hypothyroidism were 5.3%, 12.1%, 51.7%, and 85.0% according to the risk scores of 0, 1, 2, and 3, respectively.


CONCLUSIONS
Patients with a high preoperative TSH level and small thyroid volume are at high risk of developing hypothyroidism following hemithyroidectomy. Potential risk of postoperative hypothyroidism should be discussed with these patients when thyroid surgery is being considered for a diagnostic purpose.
Moon
Hyeong-Gon
HG
Department of Surgery, Gyeongsang National University Hospital, 90 Chilam-dong, Jinju, Gyeongsangnam-do, 660-702, South Korea.
Jung
Eun-Jung
EJ
Park
Soon-Tae
ST
Jung
Tae Sik
TS
Jeong
Chi-Young
CY
Ju
Young-Tae
YT
Lee
Young-Joon
YJ
Hong
Soon-Chan
SC
Choi
Sang-Kyung
SK
Ha
Woo-Song
WS