Of all patients in whom hypothyroidism developed, 40 were treated with levothyroxine. The remaining 175 patients had subclinical hypothyroidism with an average postoperative TSH in the 7 mIU/L range. These patients were followed without thyroid hormone treatment and 68.0% recovered normal thyroid function at an average time interval of 12.2 months. Despite a normal preoperative TSH level in the 2 mIU/L range, 64% of patients who underwent thyroid lobectomy experienced at least temporary post-surgical hypothyroidism. The majority of these patients had subclinical hypothyroidism, and two thirds recovered normal thyroid status. A preoperative TSH level >1.7 mIU/L was predictive of postoperative hypothyroidism and lack of recovery to normal thyroid hormone levels.
WHAT ARE THE IMPLICATIONS OF THIS STUDY?
The benefits of lobectomy over total thyroidectomy include a decreased risk of surgical complications and the potential to avoid long-term thyroid hormone supplementation. Many patients are very interested in undergoing lobectomy to retain their own thyroid function and avoid the need for long-term medication. The current study will help to inform preoperative counseling about the risk of postoperative hypothyroidism in individual patients.
This study shows that 64% of patients who undergo lobectomy will develop hypothyroidism, although in the vast majority these patients this will be mild with only a slightly increased TSH (subclinical hypothyroidism). Further, 68% of patients in whom subclinical hypothyroidism developed after surgery recovered normal thyroid function. Thus, patients with subclinical hypothyroidism after lobectomy may benefit from a prolonged period of observation without thyroid hormone therapy to determine whether the reamining lobe will eventually compensate and maintain normal thyroid function. An additional factor to consider is quality of life after surgery, particularly during a period of “subclinical” hypothyroidism. Hypothyroidism (even in the absence of overt symptoms) may contribute to this. Quality of life was not included in the current analysis but will be important to assess in future studies, particularly given the long time interval to recover the normal thyroid status.
— Ronald B. Kuppersmith, MD, FACS
ATA THYROID BROCHURE LINKS
Thyroid Surgery: https://thyroid.org/patients/patient_ brochures/surgery.html
Hypothyroidism (Underactive): https://www.thyroid.org/ hypothyroidism/
Thyroid Hormone Treatment: https://www.thyroid.org/ thyroid-hormone-treatment/