Persistent hyperparathyroidism requiring surgical treatment after kidney transplantation

There are not many publications describing long-term follow-up of persistent hyperparathyroidism requiring surgical treatment after kidney transplantation (PHSKT). In some patients adenomas, rather than multiglandular disease, have been incriminated as the cause of PHSKT. We reviewed the charts of 45 patients followed for 12 to 146 months (median 45 months) after parathyroidectomy for PHSKT. We compared them with (1) those of 951 patients receiving a kidney graft during the same period but not submitted to parathyroidectomy or (2) 90 matched controls selected from this cohort to determine the characteristics of PHSKT patients. The duration of pretransplant dialysis was significantly longer in PHSKT patients than in controls (5.78 +/- 0.41 vs. 3.41 +/- 0.24 years; p < 0.0001). A total of 166 glands were removed or biopsied. Except for one questionable case, no true adenoma was observed even when only one gland was enlarged. The outcome of surgery was not influenced by the technique (subtotal parathyroidectomy versus total parathyroidectomy and autografting) but depended on the amount of resected parathyroid tissue: no failures and 4 cases of hypoparathyroidism in 34 cases with no missing gland at cervical exploration; 3 failures and no permanent hypoparathyroidism in 11 cases with one or two missing glands. Excision of the enlarged glands only was sufficient to cure the patient. No recurrence was observed. Our results suggest that single gland enlargement in PHSKT results in most cases from different rates of involution of the parathyroids after successful kidney transplantation. When fewer than four glands are discovered, resection of all visible glands with or without grafting corrects hypercalcemia in more than 70% of the cases.