Intraoperative parathyroid hormone measurement during parathyroidectomy for treatment of primary hyperparathyroidism: When should you end the operation?

Abstract

IntroductionThe study objective was to evaluate the intraoperative 50% decrease in PTH level ± PTH normalization for its accuracy and efficiency in predicting cure during parathyroidectomy (PTx) for the treatment of primary hyperparathyroidism (PHP). MethodsA retrospective review of patients undergoing PTx was conducted. The timepoints at which the 50% PTH decrease was reached were recorded. The accuracy of intraoperative PTH for predicting cure, defined as normocalcemia at 6 months postoperatively, was evaluated. ResultsThe study population was made up of 248 PHP patients, with 247 patients achieving normocalcemia at 6 months postoperatively. If a 50% PTH decrease was used to indicate operation conclusion, 1 patient would not be cured. Persistent PTH elevation above normal range at T10 had a PPV of 77%, NPV of 99.5%, sensitivity of 95.2% and specificity of 97.3% for predicting the presence of a contralateral pathological parathyroid gland. For the study cohort, 24.5 h of cumulative operating time would be saved if the 50% PTH decrease triggered operation conclusion. DiscussionA decrease in the pre-excision PTH level to 50% of the baseline level, or a decrease in the higher of the baseline or pre-excision PTH levels by 50% at 5 or 10 min post pathological parathyroid gland removal, regardless of whether the PTH level normalizes, reliably predicts cure from PHP and should be used to guide the surgeon during parathyroidectomy.