BLOOD-SUPPLY AND PARATHYROID-HORMONE SECRETION IN PATHOLOGICAL PARATHYROID-GLANDS

The blood supply of pathologic parathyroid glands and the relation bet ween parathyroid hormone secretion and parathyroid blood perfusion was studied during surgery for hyperparathyroidism. Blood flow in 39 sing le adenomas and 20 glands classified as primary or secondary hyperplas ia were studied intraoperatively with laser Doppler flowmetry. The ips ilateral inferior thyroid artery was occluded during continuous flowme try recording, which resulted in a 40% reduction of parathyroid blood flow in both groups. In 12 patients with single adenomas, intact parat hormone (iPTH) was measured intraoperatively before and during occlusi on of the ipsilateral inferior thyroid artery and after extirpation of the adenoma. During occlusion the iPTH levels were mainly unchanged d espite blood flow reduction of up to 80%. After removal of the adenoma the iPTH normalized within 15 minutes. In a control group of eight si ngle adenomas, iPTH was measured similarly without vascular occlusion, demonstrating comparable iPTH levels. This study demonstrates similar routes of vascularization for single adenomas and hyperplastic glands , as was earlier seen for normal parathyroid glands. The increased par athyroid hormone secretion from single adenomas appears to remain main ly unchanged during significant blood flow reduction.