Intraoperative parathormone spikes during parathyroidectomy may be associated with multiglandular disease.

BACKGROUND: The importance of intraoperative parathormone "spikes" during parathyroidectomy remains unclear. This study compared patients with and without intraoperative parathormone spikes during parathyroidectomy using the criterion of a > 50% parathormone and determined the effect of intraoperative parathormone spikes on operative outcome.

METHODS: We performed a retrospective review of prospectively collected data on 683 patients who underwent parathyroidectomy guided by intraoperative parathormone monitoring. An intraoperative parathormone "spike value" was calculated by subtracting the preincision intraoperative parathormone value from the pre-excision intraoperative parathormone value (SV = PE - PI). An intraoperative parathormone spike was defined as having a positive spike value ≥9 pg/mL (≥10th percentile of all spike values).

RESULTS: Of 683 patients, 224 (33%) had intraoperative parathormone spikes and a greater rate of multiglandular disease (8% vs. 3%, P < 0.05) and bilateral neck exploration (10% vs. 5%, P < 0.05) compared with patients without intraoperative parathormone spikes. Overall, there were no differences between parathyroidectomy patients with and without intraoperative parathormone spikes in terms of operative success (98.2% vs. 98.0%), failure (1.8% vs. 2.0%), or recurrence rates (0.4% vs. 1.3%).

CONCLUSIONS: Although the presence of intraoperative parathormone spikes may increase suspicion for multiglandular disease, the ability of intraoperative parathormone monitoring to predict operative success after parathyroidectomy is not affected by spikes.