Background: Unilateral parathyroidectomy for primary hyperparathyroidism (PHPT) has a high success rate in patients with concordant imaging by sestamibi and ultrasound. However, the optimal procedure when imaging is discordant remains controversial; therefore we compared unilateral exploration with intraoperative parathyroid hormone (IOPTH) monitoring to bilateral neck exploration without IOPTH monitoring in patients with discordant localization studies.
Methods: We conducted a retrospective study of 324 consecutive patients with PHPT treated at our institution from October 2005 to September 2009. We collected information regarding imaging, localization site, procedure performed, operative time, and calcium/PTH measurements.
Results: Of the 324 patients in the study, 79 (24 %) had discordant imaging by sestamibi and ultrasound. Of these, 62 patients (78 %) underwent bilateral neck exploration without IOPTH monitoring, and 14 patients (18 %) had unilateral exploration with IOPTH monitoring. IOPTH monitoring during unilateral exploration correctly predicted removal of single adenomas in 10/14 patients (71 %) and altered operative management in 4/14 cases (29 %), resulting in conversion to bilateral neck exploration. Operative time for unilateral exploration with IOPTH [median time: 96 min (range: 51-153 min)] was significantly increased relative to bilateral exploration [median time: 52 min (range: 28-149 min)]; p = 0.0027. We identified single-gland disease in 53/76 patients (70 %), double adenomas in 13/76 patients (17 %), and multiglandular hyperplasia in 10/76 patients (13 %). There was no difference in cure rate between these two surgical approaches (p = 1.0) CONCLUSIONS: In contrast with prior studies, we found that operative time for unilateral exploration with IOPTH was significantly increased compared to bilateral neck exploration. In patients with discordant imaging, IOPTH is a useful adjunct in limiting exploration to a single side despite a high false negative rate.