Thyroid hormone replacement following lobectomy: Long-term institutional analysis 15 years after surgery

The decision to pursue lobectomy versus total thyroidectomy is highly individualized. The rate of thyroid hormone replacement therapy after lobectomy varies considerably (15%-48%) and studies are limited by short-term follow-up. We sought to assess long-term thyroid hormone replacement therapy-requirement for lobectomy.

Patients undergoing lobectomy from January 2005 to July 2010 at an academic institution were reviewed. Demographic, laboratory, pathology, and thyroid hormone replacement therapy use were compared.

In total, 235 patients were included. The rate of thyroid hormone replacement therapy after lobectomy was 46.8% (110/235). The majority were female (84.7%), with a mean age of 52 ± 1 years, 97% with benign pathology, and the median duration of follow-up was 7.2 years. Among the 110 thyroid hormone replacement therapy, the mean postoperative thyroid stimulating hormone level 9.08 ± 0.96m IU/L and the time to thyroid hormone replacement therapy-initiation was 621 days; 24% started therapy ≥2 years after surgery. There was no difference in age, sex, or malignancy. Hashimoto thyroiditis was diagnosed in 21.8% patients who underwent thyroid hormone replacement therapy versus 8.0% of those without thyroid hormone replacement therapy (odds ratio 3.2; 95% confidence interval, 1.43-6.79; P < .001). On multivariate analysis, only Hashimoto thyroiditis was independently associated with thyroid hormone replacement therapy use (odds ratio 2.88; 95% confidence interval, 1.3-6.6; P = .012).

With long-term follow-up, nearly 50% of patients who underwent lobectomy for benign disease required thyroid hormone replacement therapy and nearly one-quarter of these patients not starting until ≥2 years after surgery. Therefore, patients who undergo thyroid lobectomy should be counseled appropriately and thyroid function followed for a minimum of 2 years.