Development of hypothyroidism following hemithyroidectomy: A population-based study.

Area of Science:

• Endocrinology
• Surgical Oncology
• Public Health

Background:

• Hypothyroidism is a potential complication following hemithyroidectomy.
• The reported incidence of hypothyroidism post-hemithyroidectomy varies significantly in existing literature (8-60%).

Purpose of the Study:

• To evaluate the incidence of hypothyroidism after hemithyroidectomy.
• To specifically assess the incidence of hypothyroidism in patients with pre-existing Hashimoto's disease undergoing hemithyroidectomy.

Main Methods:

• A retrospective analysis of 6845 patients who underwent hemithyroidectomy within the last 15 years was conducted using the TriNetX research network.
• Exclusion criteria included prior thyroid surgery, thyroid cancer history, pre-operative levothyroxine use, or elevated Thyroid Stimulating Hormone (TSH) levels (≥4 mIU/L).
• Postoperative hypothyroidism was defined by International Classification of Diseases codes, TSH levels (≥4 mIU/L), or initiation of levothyroxine treatment within 3 months.

Main Results:

• The overall 3-month incidence of hypothyroidism after hemithyroidectomy was 23.58%.
• The median time to diagnosis of hypothyroidism was 41.8 months post-surgery.
• In a subgroup of patients with Hashimoto's disease, the 3-month incidence of hypothyroidism was 31.1%.

Conclusions:

• This population-based study offers valuable insights into the incidence of hypothyroidism following hemithyroidectomy.
• Findings can aid in improving perioperative patient counseling and clinical management strategies for this patient group.