Endocrine Abstracts

Selective Parathyroid Venous Sampling in Patients with Complicated Primary Hyperparathyroidism

CM Ogilvie, PL Brown, M Matson, R Carpenter, WM Drake, PJ Jenkins, SL Chew, JP Monson

Centre for Endocrinology and Departments of Surgery and Radiology, St Bartholomew's Hospital, QMUL, London EC1A 7BE

The role of pre-operative localisation of abnormal parathyroid glands remains controversial but is particularly relevant to the management of patients with recurrent or uncured hyperparathyroidism and familial syndromes. We present our 10 year experience of the use of parathyroid venous sampling in complicated primary hyperparathyroidism. Venous sampling was used in patients who had undergone previous neck surgery, had familial hyperparathyroid syndromes, non-concordant or negative MIBI and ultrasound/CT/MR scans or imaging evidence of multiple abnormalities. A total of 23 patients were studied (13 recurrent/uncured, 8 MEN1, 1 familial hyperparathyroidism, 1 tertiary hyperparathyroidism). Transfemoral venous catheterisation was performed and serum parathormone measured in samples from high and low internal jugular, thyroid, inferior thyroid, thymic mediastinal, subclavian, innominate, azygos, left superior intercostal veins, superior vena cava and right atrium. A gradient of >2 vs. peripheral parathormone concentration was considered positive for localisation and absence of a mediastinal gradient as negative for the presence of intrathoracic parathyroid pathology. 21 patients underwent surgery and in 12 of these the catheter results were completely concordant with surgical and histological findings; 4 catheters were indicative of mediastinal disease and 6 catheters were judged to be useful in excluding mediastinal disease. 6 catheters gave a false negative and 3 a false positive result. Of 13 patients referred after previous failed surgery, 12 underwent further surgery which was curative in 9. In total, 15 catheters out of 21 in patients undergoing surgery yielded useful positive (n=10) and/or negative information (n=6). Parathyroid venous sampling is a valuable adjunct to cross-sectional and isotopic imaging in patients with complicated hyperparathyroidism.