Influence of the position and size of the hyperfunctioning parathyroid gland on intraoperative PTH levels collected from the ipsilateral jugular and peripheral veins

Introduction: Primary hyperparathyroidism (PHPT) has an estimated prevalence of 0.78%.Its most frequent presentation is sporadic and uniglandular.In surgical treatment, the measurement of intraoperative parathyroid hormone (IOPTH) is fundamental in ensuring therapeutic success.The position and size of the hyperfunctioning parathyroid gland may influence baseline IOPTH values at different collection sites.Objective: Examine the relationship between the position and size of the parathyroid gland and baseline IOPTH values from the ipsilateral internal jugular vein (PTH-c), peripheral vein (PTH-p), and the absolute and percentage differences between these measurements (ΔPTHc-p and Δ%PTHc-p).Methods: A retrospective analysis was conducted on patients undergoing parathyroidectomy for sporadic uniglandular PHPT.Results: Of the 300 eligible patients, 54 were males and 246 females, with a median age of 59 years.Right superior glands exhibited larger volumes and higher ΔPTHc-p and Δ%PTHc-p values compared with the right inferior glands.Left superior glands displayed higher Δ%PTHc-p values than the left inferior glands.Larger glands showed increased PTH-p, PTH-c, and ΔPTHp-c values.No correlation was found between volume and Δ%PTHp-c.Conclusion: The position of the parathyroid gland, either superior or inferior, influences the difference between PTH-c and PTH-p values.Glandular volume correlates with ΔPTHc-p but not with Δ%PTHc-p.Elevated Δ%PTHc-p measurements may be of intraoperative significance, indicating a superior position of the gland.