Background and aims: Intra-operative parathyroid hormone (IOPTH) results are not known in the setting of tertiary hyperparathyroidism (HPT) after renal transplantation. Materials and methods: A retrospective analysis of 35 tertiary HPT patients who all underwent subtotal parathyroidectomy and IOPTH monitoring was conducted. Results: The mean follow-up time was 2.2±1.4years. Thirty-four patients were cured; one patient (2.8%) had a persistent disease and was cured after reoperation. Median parathyroid hormone (PTH) (median percent decrease from highest) at baseline and at 5, 10, 20, and 30min were 244, 78 (69%), 63 (75%), 53 (79%), and 49pg/ml (83%), respectively. Four patients who were cured had a decrease of 50% at 10min. The sensitivity of the test was 94% at 10min using the Miami criteria. Conclusion: This study shows that IOPTH in tertiary hyperparathyroidism has a high sensitivity. However, because of the low risk of persistent hyperparathyroidism when a subtotal parathyroidectomy is performed, its potential impact on the overall success rate is very small. We therefore do not recommend the routine use of IOPTH in tertiary hyperparathyroidis
