Retrospective analysis of the role of intra-operative parathyroid hormone monitoring during parathyroidectomy for primary hyperparathyroidism; a single center experience over 2 decades

Background: The role of intra-operative parathyroid hormone (IOPTH) monitoring during parathyroidectomy for primary hyperparathyroidism has long been debated. Objectives: Our main goal was to investigate the cure rates of parathyroidectomy for primary hyperparathyroidism with and without IOPTH monitoring. Our secondary goal was to investigate if operating room time can be saved when not using IOPTH monitoring. Design: A retrospective analysis of patients who underwent parathyroidectomy for PHPT for a single adenoma between 2004-2019 was performed. Cure rates and operating room time were compared. Results: 423 patients were included. IOPTH was used in 248 patients (59%). Four patients were not cured, two from each group, with no significant difference between the groups (98.8% vs. 99.1%, p=0.725). Surgery time was significantly longer in the IOPTH group, p<0.001. Conclusions: There is no advantage for using IOPTH during parathyroidectomy in suitable clinical setting. A focused procedure may be safely performed without IOPTH while achieving non-inferior success rates and reducing operative time.

Feasibility of Intraoperative Parathyroid Hormone Monitoring in Minimally Invasive Surgery

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.

Recent advances in the understanding and management of primary hyperparathyroidism

Primary hyperparathyroidism is a hormonal disorder whose prevalence is approximately 1–2% in the United States of America. The disease has become more recognizable to clinicians in an earlier phase and, at present, patients can be diagnosed with “classic”, “normocalcemic”, “normohormonal”, or “mild, asymptomatic” primary hyperparathyroidism. Surgery, with a focused parathyroidectomy when possible, or a four-gland exploration, is the only way to cure the disease. Cure is determined by use of intra-operative parathyroid hormone monitoring with long-term cure rates ranging from 90–95%. Newer adjuncts to surgery include CT or PET imaging and near-infrared immunofluorescence. This article highlights updates in parathyroid disease and advances in parathyroid surgery; it does not provide a comprehensive summary of the disease process or a review of surgical indications, which can be found in the AAES guidelines or NIH Symposium on primary hyperparathyroidism.