Total thyroidectomy boosted patient-reported general health in euthyroid Hashimoto's thyroiditis for up to 5 years, an extension of a randomized trial showed.

Measured via the Short Form-36 Health Survey, the big bump in quality of life right after thyroidectomy was fully maintained among 65 patients who were tracked for 60 months post-surgery, Geir Hoff, MD, PhD, of the University of Oslo in Norway, and colleagues reported.

Prior to surgery, patients' average general health score was around 40 on the 0-100 scale, where the highest score indicates no disability. Five years after surgery, their score continued to be around 70, they detailed in a letter in the Annals of Internal Medicine.

At the end of the initial 18-month trial published in 2019, those who underwent total thyroidectomy scored 29 points higher (95% CI 22-35 points) on the Short Form-36 Health Survey compared with patients who only had hormonal medical management.

"The primary endpoint in the study was patient experience and the patients' own estimate of 'general health' using a validated questionnaire -- i.e. a very 'soft' endpoint and very prone to give scores that could be explained by placebo effects of surgery," Hoff explained to MedPage Today. "Placebo effects in drug trials may be expected to last only for a limited time. Although expected duration of observed drug-placebo effects cannot be extrapolated to surgery, we felt obliged to follow the effect seen after 18 months for as long as possible -- up to 5 years -- in this study."

"A gradual tapering of the effect seen at 18 months would suggest a high degree of placebo, but the maintained effect now seen after 5 years does not exclude a placebo mechanism," he added.

Despite the sustained jump in quality of life, total-thyroidectomy patients ran into a few bumps along the way. During follow-up, 10 of the 73 surgery patients (14%) experienced long-term complications, while another 13 had short-term complications lasting less than a year. These included recurrent laryngeal nerve paralysis, hypoparathyroidism, and postoperative hematoma or infection.

"The study was based on the hypothesis that any auto-antigen thyroid tissue left behind at thyroidectomy might contribute to maintain an antigen-antibody response and persistent symptoms," Hoff explained. "Therefore, a more stringent dissection than usual was performed to achieve total thyroidectomy, carrying a higher risk of nerve palsy and hypoparathyroidism."

While this was an "unacceptably high" complication rate, as dubbed by the researchers, Hoff pointed out that these complications still didn't seem to affect patients' general health scores. Nonetheless, this high complication rate should give clinicians pause before moving forward with total thyroidectomy for this particular patient population.

"Total thyroidectomy for euthyroid patients with Hashimoto disease and persistent symptoms may achieve an improved sense of good health, but at the risk of a high complication rate," said Hoff. "This, combined with lack of a documented, satisfactory pathophysiological mechanism to explain these findings, leads up to not recommending this as a treatment option unless centralized to dedicated centers as part of further research."

All adults included in the study had chronic and persistent Hashimoto's-related symptoms. The surgical group was on a 618 μg (range 157 to 1,450 μg) median weekly dose of levothyroxine compared with a 550 μg (range 88 to 1,500 μg) weekly dose for the medical management group at baseline.

During follow-up, levothyroxine dose was adjusted every third month if necessary to maintain euthyroid status. All had serum antithyroid peroxidase antibody titers >1,000 IU/mL and thyroid-stimulating hormone levels >3.5 mIU/L before hormone replacement. A total of 73 received surgery while another 74 only received medical treatment.

Over the 5-year follow-up, the Short Form-36 dimensions for total fatigue and chronic fatigue also maintained significant improvements. At the 18-month mark, fatigue score decreased from 23 to 14 points and chronic fatigue frequency decreased from 82% to 35%.