Feasibility of intraoperative parathyroid hormone monitoring in minimally invasive surgery

Abstract

Background and Objectives There has been a long debate on whether intraoperative parathyroid hormone (IOPTH) monitoring is mandatory or not in the excision of a single abnormal parathyroid gland. The aim of this study is to suggest a new criteron of IOPTH monitoring. Subjects and Method We retrospectively analyzed 31 patients who underwent parathyroidectomy from 2005 to 2019. Patients had IOPTH not measured and those with secondary hyperparathyroidism were excluded. IOPTH was measured preoperatively (EX00), at 10 minutes (EX10) and 20 minutes (EX20) after the excision and analyzed. We determined the surgery as a 'successful excision of lesion (SEOUL)' when it met the following criteria: Criterion 1) the level of EX10 or EX20 decreased under the upper normal or under upper limit of parathyroid hormone (65 pg/mL); criterion 2) EX20 decreased below 50% of EX00 and less than 195 pg/ mL (3 times the upper normal limit); criterion 3) multiglandular disease. Results Twenty-five patients among 31 patients were included this study (M:F=8:17). Twenty- two patients were suspected of single lesion and three patients of multiple lesions on preoperative images (99mTc-sestamibi scan, neck CT, and PET-CT). IOPTH of EX00, EX10, and EX20 were 488.92±658.74, 121.36±134.73, and 92.44±111.55 pg/mL, respectively. Sixty-four percent patients (16/25) met the criterion 1. Six patients (24%) successfully excised a lesion meeting the criterion 2. Three patients had multiglandular disease, meeting the criterion 3. Conclusion Our new criteria suggest when we could stop the procedure. If the level of IOPTH does not meet the SEOUL criteria, it means that there might be more lesions. © 2021 Korean Society of Otorhinolaryngology-Head and Neck Surgery.