Thyroid function after subtotal thyroidectomy for hyperthyroidism

Area of Science:

• Endocrinology
• Thyroidology
• Surgical Endocrinology

Background:

• Subtotal thyroidectomy is a common treatment for hyperthyroidism.
• Long-term thyroid function after surgery requires further investigation.
• Assessing postoperative thyroid hormone levels is crucial for patient management.

Purpose of the Study:

• To evaluate long-term thyroid function in patients after subtotal thyroidectomy for hyperthyroidism.
• To investigate the relationship between serum thyroid-stimulating hormone (TSH), thyroxine (T4), and triiodothyronine (T3) levels post-surgery.
• To determine if subtotal thyroidectomy leads to progressive thyroid function deterioration.

Main Methods:

• Analysis of thyroid function tests in 76 patients one to seven years post-subtotal thyroidectomy.
• Measurement of serum TSH, thyroxine (T4), and triiodothyronine (T3) levels.
• Clinical assessment of patients' thyroid status.

Main Results:

• Recurrent hyperthyroidism occurred in 3 patients, and hypothyroidism in 13.
• 60 of 76 patients were clinically euthyroid, but 39 had elevated TSH (>5.0 mU/ml).
• Patients with elevated TSH had lower T4 but similar T3 levels compared to those with normal TSH, indicating euthyroidism via T3 compensation.

Conclusions:

• Elevated TSH in clinically euthyroid patients post-thyroidectomy is compensated by normal T3 levels.
• Subtotal thyroidectomy for hyperthyroidism does not appear to cause long-term progressive thyroid function decline.
• Monitoring TSH and T3 is important for assessing thyroid status after surgery.