INTRAOPERATIVE PARATHYROID-HORMONE ASSAY FOR SIMPLIFIED LOCALIZATION OF PARATHYROID ADENOMAS

Lack of success in parathyroid surgery is usually due to failure to id entify the abnormal parathyroid gland correctly at operation. The surg eon may be helped by rapid parathyroid hormone (PTH) assay in peripher al blood after removal of a suspected adenoma, and by frozen section h istology, but these are not true localization techniques, We have adap ted a non-isotopic immunoassay for rapid measurement of PTH in samples from the upper, middle and lower thyroid veins taken at operation, be fore exploration begins. Fifteen patients with primary hyperparathyroi dism were operated on, In 10 the parathyroid adenoma was located easil y, and was associated with high local venous PTH levels, In four patie nts the abnormal parathyroid was not immediately apparent but the assa y indicated its location, which was confirmed after further exploratio n, In one patient there was no difference in PTH levels in the six ven ous samples. An ectopic adenomatous gland was successfully identified behind the thymus, The operation was successful in all patients as sho wn by a fall in the plasma calcium to the normal range. We conclude th at intra-operative selective venous sampling and rapid PTH assay facil itates operative localization of parathyroid adenomas.