Parathyroid Hormone Concentration From Internal Jugular Veins of Patients With Primary Hyperparathyroidism: A Cohort Study

Introduction: Surgical intervention remains the only curative therapy for primary hyperparathyroidism (PHPT) . The objective of the study is to evaluate whether the values of parathyroid hormone (PTH) collected from the internal jugular veins of patients with PHPT can assist in the surgical approach.

Methods: This was a prospective study, from April 2018 to November 2023, of patients with PHPT who underwent parathyroidectomy. Data was collected from medical records on gender, age, exams, surgery performed and complications. As a study protocol, PTH samples were collected from the internal jugular veins. Inclusion criteria were patients diagnosed with PHPT (elevated PTH and symptomatic or asymptomatic hypercalcemia) and eligible for surgery. Statistical analysis, numerical variables were expressed as mean and standard deviation of minimum and maximum values, and categorical variables as number and percentage. For nonparametric values analysis of variance (ANOVA) was used, followed by Tukey’s a posteriori test considering a statistically significant p-value < 0.05.

Results: A total of 124 patients underwent surgery. All patients had a decrease in peripheral PTH greater than 50% with a mean of 72%. PTH collection from the internal jugular veins was positive regarding the confirmation of parathyroid adenoma laterality in 102 cases (82.3%) (p = 0.001). Comparing the success rates of the methoxyisobutylisonitrile parathyroid scintigraphy (MIBI), parathyroid ultrasonography (USG) and PTH of internal jugulars in relation to location of adenoma laterality, we observed Jugular PTH as localizer in 82.3% of the cases followed by MIBI whit 77.4% and USG with 41.9%. Receiver Operating Characteristic (ROC) curve analysis was conducted to identify the optimal cutoff point for the percentage difference in Parathyroid Hormone (PTH) levels from the jugular veins. Area Under the Curve (AUC) was 0.882, and the optimal cutoff point was 16.7%, with 76.5% sensitivity and 95.5% specificity.

Conclusions: PTH collection from the internal jugular veins is useful in patients with PHPT as a possible method of localized exams, indicating adenoma laterality.