Endocrine Abstracts

Introduction: The only curative treatment of primary hyperparathyroidism (pHPT) is surgery. Accurate pre-operative localization of abnormal parathyroid glands is an essential prerequisite to reduce the complication risk associated with surgery. We aimed to determine the diagnostic value of jugular venous sampling (JVS) in cases of pHPT in which the location of parathyroid adenomas could not be determined through various preoperative imaging studies.

Methods: A retrospective study was conducted with 22 patients with pHPT who underwent bilateral JVS. The samples were collected from the most inferior portion of each internal jugular vein and sent for standart PTH measurement. >10% gradient difference between the sides was accepted as positive. The patients’ laboratory results, preoperative ultrasonography (US) and parathyroid scintigraphy findings, JVS results, and postoperative pathology results were recorded.

Results: JVS was performed in 22 patients (1 M/21 F) with pHPT. 15 of the patients had negative ultrasound and scintigraphy findings. Gradient differences were found in a total of 12 patients (54%), 9 on the right and 3 on the left. Gradient difference was found in JVS in 6 patients with negative scintigraphy and in 5 patients with negative US findings. Although 4 of them were positive in ultrasound and 3 of them were positive in scintigraphy, no gradient difference was found in JVS. Among 12 patients, the JVS gradient localization was found to be incompatible with surgical exploration in only one patient. All patients’ pathology results were reported as parathyroid adenoma.

Discussion: In cases with small or multiple parathyroid lesions, the location of lesions cannot be determined using US and ^99mTc-sestamibi SPECT. JVS is generally recommended to lateralize the lesion in scintigraphy-negative patients undergoing primary surgery. Alvarado et al. found a 56% positive lateralization in a study with both positive and negative pHPT patients, and a positive lateralization of 76% in the control group without parathyroid disease. The authors reported that JVS was not sufficient to determine the location of imaging negative parathyroid adenomas. On the otherhand, Denise et al. found that JVS was correct in in localization the side of the abnormal gland in 81% of the patients with pHPT.

Conclusions: JVS may be used as an adjunctive technique for preoperative localization of parathyroid lesions that cannot be located by non-invasive imaging studies if a gradient difference is reached and more extensive studies are needed to confirm the role of this tecnique before surgery.