Int J Thyroidol.  2023 May;16(1):120-127. 10.11106/ijt.2023.16.1.120.

Effects of Isthmus Preservation on Postoperative Hypothyroidism after Lobectomy

• Jeon YS
• Kim WW

• KMID: 2543019
• DOI: http://doi.org/10.11106/ijt.2023.16.1.120

Abstract

Background and Objectives
Many patients experience hypothyroidism after lobectomy. The purpose of this study was to investigate the effects of the extent of surgery (isthmus-saving lobectomy vs. isthmus-removing lobectomy) on postoperative hypothyroidism after lobectomy.
Materials and Methods
In total, 144 consecutive benign or low-risk papillary thyroid cancer patients with euthyroid status were retrospectively enrolled from January 2016 to June 2018; 100 patients underwent isthmus-saving lobectomy (IS group), and 44 patients underwent isthmus-removing lobectomy (IR group). Thyroid function tests (TSH) were performed at 3, 6, 12, and 24 months after surgery. Levothyroxine was administered to patients with overt hypothyroidism and those with subclinical hypothyroidism who complained of obvious symptoms of hypothyroidism.
Results
The TSH level was significantly lower in the IS group at 3 and 6 months after surgery (p=0.049 and 0.026, respectively). Among patients with TSH ＜2 μIU/mL preoperatively, 17 patients (17/66=25.8%) in the IS group had significantly maintained TSH levels at ＜2 μIU/mL compared with 2 patients (2/21=9.5%) in the IR group even after surgery (p=0.039). Postoperative overt hypothyroidism was found in 5 patients (5.0%) in the IS group and 6 patients (13.6%) in the IR group (p=0.048), and the numbers of patients who took medication after the surgery, 10 (10%) and 14 (31.8%), were significantly lower in the IS group (p=0.001).
Conclusion
Isthmus-saving lobectomy in patients with euthyroid status reduced the incidence of postoperative hypothyroidism and thyroid hormone replacement and helped in maintaining a low TSH level when compared with isthmus-removing lobectomy.

Keyword

Isthmus; Lobectomy; Hypothyroidism

Figure

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  Fig. 1 Isthmus-saving right lobectomy and isthmus-removing right lobectomy.

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  Fig. 2 As a follow-up flow of the patient, medication was administered if overt hypothyroidism or subclinical hypothyroidism with obvious symptoms occurred.

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  Fig. 3 As a result of all patients, the incidence of overt hypothyroidism and medi-cation was lower in the isthmus-saving lobectomy group.

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  Fig. 4 As a result of patients with a preoperative TSH of <2, the number of patients with a TSH <2 was higher in the isthmus-saving lobectomy group postoperatively.

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  Fig. 5 As a result of patients with preoperative TSH of ≥3 and <4.2, the incidence of hypothyroidism and medication was less in the isthmus-saving lobectomy group.

Reference

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