BACKGROUND
Thyroid surgery is done for both cancer and noncancerous (benign) conditions. Thyroid surgery can remove the whole thyroid (total thyroidectomy) or just a lobe (lobectomy) if that is all that is needed. For a variety of reasons, thyroid lobectomy is recognized to be preferred over removing the entire thyroid gland when possible. The most important reason is that patients many not need to be on life-long thyroid hormone replacement if they undergo a lobectomy. As such, there is an increasing number of adults and children who undergo this procedure. Although the majority of adult patients continue to have normal thyroid function after lobectomy, it is known that 15-30% of adults develop hypothyroidism and need to start thyroid hormone. Despite the fact that the frequency of lobectomy is also increasing in children, there is limited data regarding the risk of hypothyroidism in children and teenagers after having this operation.

This study was done to increase understanding of the risk of hypothyroidism in children after having a thyroid lobectomy in order to improve counseling to patients and their families before the surgery and to recommend management after the procedure.

THE FULL ARTICLE TITLE
Baran JA et al 2021 Clinical course of early postoperative hypothyroidism following thyroid lobectomy in pediatrics. Thyroid 31:1786–1793. PMID: 34714171.

SUMMARY OF THE STUDY
This study was done by reviewing medical charts of all patients younger than 19 years of age who underwent a thyroid lobectomy at Children’s Hospital of Philadelphia between 2004 and 2020. Patients who were noted to have had a second surgery to remove the remaining lobe within 12 months of the initial surgery, who did not have record of thyroid blood tests after surgery, who had Hashimoto’s thyroiditis, or who were prescribed levothyroxine even if thyroid levels were normal after surgery were excluded from the analysis.

A group of 110 patients met criteria for inclusion in study. They were separated in groups according to the TSH level obtained after surgery. These groups were : Normal: (TSH 0.45-4.5), Subclinical hypothyroidism ( TSH 4.51-10.0); overt hypothyroidism ( TSH >10) or hyperthyroidism ( TSH <0.45). Transient (short-lived) hypothyroidism was defined as having a temporary elevation of TSH ( >4.5), recovering to normal within 12 months after surgery.

The study included 94 female and 16 male patients with an average age of 14.9 years. Transient hypothyroidism developed in 17.5% of patients and permanent hypothyroidism in 7.8%. The majority of patients who required levothyroxine therapy began treatment in the first postoperative month although 2 patients needed to start treatment after the 12 month mark. Patients who had a suppressed TSH prior to surgery because of an overactive thyroid nodule had a higher risk of developing hypothyroidism after surgery.

WHAT ARE THE IMPLICATIONS OF THIS STUDY?
This study shows that the majority of children who undergo a lobectomy will have normal thyroid hormone levels within 12 months after surgery, Based on these findings, the authors suggest evaluating thyroid function at 4-6 weeks after a lobectomy, and every 3 months thereafter up to 12 months after surgery for those patients who have a TSH in the subclinical range ( >4.5 and <10). Levothyroxine should be started if TSH remains in the subclinical range or continues to trend upwards after 12 months. A shorter length of observation with initiation of treatment should be pursued for patients with TSH >10.0 after lobectomy. This is important for patients to discuss with their providers when evaluating surgical treatment options for thyroid disease in children.

— Jessie Block-Galarza, MD

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