Intraoperative parathyroid hormone estimation: a valuable adjunct to parathyroid surgery.

Serial measurements of serum intact parathyroid hormone (PTH) and adjusted total calcium levels were performed on 10 patients during unilateral neck exploration for a solitary parathyroid adenoma localised preoperatively by ultrasound scan. Frozen section was performed peroperatively to establish the presence of parathyroid tissue. Levels of PTH were shown to be within the normal range within 15 min of adenoma removal (a mean of 13.4% of their preoperative values), allowing clear early distinction from unsuccessful surgery where no change occurred. Frozen section wrongly identified thyroid tissue as parathyroid in one case leading to a failure of the initial neck exploration. Our findings show that intraoperative PTH measurements can accurately predict whether all hyperfunctioning parathyroid tissue has been removed. This is not always possible using frozen section techniques. The wider use of intraoperative PTH measurement, particularly in difficult cases, may avoid the need for prolonged explorations to identify all four glands and, perhaps, biopsy of normal glands, replacing the current standard use of frozen section as a more reliable indicator of the success of parathyroid surgery.