Clinical Features of Early and Late Postoperative Hypothyroidism After Lobectomy.
Lobectomy is preferred in thyroid cancer to decrease surgical complications and avoid lifelong thyroid-hormone replacement. However, postoperative hypothyroidism, requiring thyroid-hormone replacement, may occur.



We aimed to identify the incidence and risk factors of postoperative hypothyroidism to develop a surveillance strategy after lobectomy for papillary thyroid microcarcinoma (PTMC).



This historical cohort study involved 335 patients with PTMC treated by lobectomy. Postoperative thyroid functions were measured regularly, and patients were prescribed levothyroxine according to specific criteria. Patients not satisfying hormone-replacement criteria were closely followed up.



Postoperative hypothyroidism occurred in 215 patients (64.2%) including 5 (1.5%) with overt hypothyroidism and 210 (62.7%) with subclinical hypothyroidism. Forty patients (11.9%) were required thyroid hormone replacement. One hundred nineteen patients (33.5%) experienced temporary hypothyroidism and spontaneously recovered to euthyroid state. High preoperative thyroid-stimulating hormone (TSH) was the most important factor predicting postoperative hypothyroidism and failure of recover from hypothyroidism (odds ratio [OR], 2.82 and 1.77; 95% confidence interval [CI], 2.07 to 3.95 and 1.22 to 2.63; P < 0.001 and 0.002, respectively). Of the 215 patients eventually developing postoperative hypothyroidism, 70 (32.6%) developed hypothyroidism after the first postoperative year. Postoperative 1-year TSH levels were able to differentiate patients developing late hypothyroidism or euthyroidism (OR, 2.29; 95% CI, 1.68 to 3.26; P < 0.001).



Preoperative and postoperative TSH levels might be predictive for patients who develop postlobectomy hypothyroidism and identify those requiring long-term surveillance for hypothyroidism. Additionally, mild postoperative hypothyroidism cases should be followed up without immediate levothyroxine replacement with the expectation of spontaneous recovery.
Departments of Internal Medicine and.
Suyeon
S
Park
Departments of Internal Medicine and.
Min Ji
MJ
Jeon
Departments of Internal Medicine and.
Eyun
E
Song
Departments of Internal Medicine and.
Hye-Seon
HS
Oh
Departments of Internal Medicine and.
Mijin
M
Kim
Departments of Internal Medicine and.
Hyemi
H
Kwon
Departments of Internal Medicine and.
Tae Yong
TY
Kim
Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea.
Suck Joon
SJ
Hong
Departments of Internal Medicine and.
Young Kee
YK
Shong
Departments of Internal Medicine and.
Won Bae
WB
Kim
Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea.
Tae-Yon
TY
Sung
Departments of Internal Medicine and.
Won Gu
WG
Kim
D000328:Adult; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D002291:Carcinoma, Papillary / Q000453:epidemiology* / Q000534:rehabilitation / Q000601:surgery*; D015331:Cohort Studies; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D007037:Hypothyroidism / Q000188:drug therapy / Q000453:epidemiology* / Q000209:etiology* / Q000473:pathology; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000188:drug therapy / Q000453:epidemiology* / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000453:epidemiology* / Q000534:rehabilitation / Q000601:surgery*; D013965:Thyroidectomy / Q000009:adverse effects* / Q000379:methods; D013974:Thyroxine / Q000627:therapeutic use; D013997:Time Factors
D013974:Thyroxine