The use of high-resolution ultrasound to locate parathyroid tumors during reoperations for primary hyperparathyroidism

In a previous report we compared intraoperative ultrasound (IOUS) to preoperative ultrasound (US) in 25 consecutive patients undergoing reoperations for primary hyperparathyroidism. We demonstrated the superior effectiveness of IOUS to image abnormal parathyroid glands compared to US, and a 50% reduction in operative time resulting from this superior imaging capability. The present study extends these comparisons of preoperative imaging techniques to include computed tomography (CT) and technetium/thallium scintigraphy (Tc/Tl) in an updated series of 39 patients undergoing reoperative parathyroid surgery. All 39 patients underwent successful reoperations for either parathyroid adenoma (34 patients), parathyroid hyperplasia (4 patients), or parathyroid carcinoma (1 patient). IOUS was more effective than preoperative US, CT scan, or Tc/Tl scintigraphy in imaging 41 abnormal glands in these 39 patients. IOUS was not dependent on size or anatomic location of an abnormal gland for successful imaging. Abnormal glands in unusual locations, such as intrathyroidal adenomas or undescended adenomas, were imaged accurately with IOUS. Multiglandular disease was detected by IOUS, with correct imaging of 3 hyperplastic glands in a single patient; no other imaging technique was able to identify more than 1 abnormal gland in any patient. No imaging study (including IOUS restricted to the neck alone) was able to identify accurately a mediastinal parathyroid adenoma (1 patient). A clinical decision analysis revealed that IOUS had the highest sensitivity and positive predictive value of any imaging study. IOUS is thus a tool to be used by the surgeon in reoperations for parathyroid disease to facilitate dissection and identification of abnormal glands. When positive, IOUS can help the surgeon proceed quickly and easily to the location of abnormal tissue.