M. LoPinto1, G. A. Rubio1, Z. F. Khan1, T. M. Vaghaiwalla1, J. I. Lew1 1University Of Miami,Division Of Endocrine Surgery, DeWitt Daughtry Family Department Of Surgery,Miami, FL, USA
Introduction: Despite effective preoperative localization of single abnormal parathyroid glands for targeted parathyroidectomy (PTX) in patients with primary hyperparathyroidism (pHPT), localization failure by imaging studies can nevertheless occur. Knowledge of parathyroid gland location remains paramount, and provides the surgeon with a starting point for PTX when preoperative gland localization is unsuccessful. This purpose of this study was to determine any difference in the anatomic location for single abnormal parathyroid glands, which may help guide the surgeon in PTX when preoperative localization is unavailable or negative in patients with pHPT.
Methods: A retrospective review of prospectively collected data of 824 consecutive patients with pHPT who underwent initial PTX at a tertiary medical center was performed. All patients had elevated serum calcium and parathormone (PTH) levels above normal reference range, and single gland disease. Eutopic location of abnormal parathyroid glands in each patient was determined at time of operation, correlated with operative and pathology reports, and confirmed by operative success. Operative success was defined as continuous eucalcemia for >6 months after PTX. Patients with MEN, secondary, tertiary or familial hyperparathyroidism, multiglandular disease (MGD), parathyroid cancer and ectopic glands were excluded. Data were analyzed by chi squared and Z test analyses.
Results: Of these patients, single abnormal parathyroid glands were not evenly distributed among their 4 eutopic locations in the neck (left superior, n=128 (15.5%), left inferior, n=259 (31.4%), right superior, n=131 (16%), right inferior, n=306 (37.1%); p<0.0001). Abnormal inferior parathyroid glands were significantly more common than abnormal superior glands, respectively (n=565 (68.6%) vs. n=259 (31.4%); p <0.0001). Overall, there was no significant difference in abnormal gland laterality (right, n=437 (53%) vs. left, n=387 (47%), p=0.08). However, in the subset of men, the most common location for abnormal parathyroid glands was right inferior position (43.5%, 95% CI 36.3-50.8% p<0.0001).
Conclusion: This large series of patients with pHPT suggests that single eutopic abnormal parathyroid glands are more likely to be found in the inferior location. In women, this finding can be used in conjunction with intraoperative selective venous sampling and/or parathyroid hormone monitoring for further lateralization of abnormal gland position. In men, however, if an abnormal parathyroid gland is not localized preoperatively, the right inferior location should be explored first. Nevertheless, success of such operations remains predicated on knowledge of parathyroid anatomy and the experience and judgement of the surgeon.