Persistently Elevated Parathyroid Hormone Despite Successful Parathyroid Surgery

Abstract

Objectives: (1) Recognize that a number of patients with primary hyperparathyroidism will continue to manifest elevated parathyroid hormone (ePTH) despite achieving eucalcemia after curative parathyroidectomy. (2) Identify the preoperative factors that may contribute to this phenomenon. (3) Counsel patients and physicians regarding these factors to prevent unnecessary reoperative surgical procedures in response to postoperative elevated parathyroid hormone. Methods: Records of all patients who underwent curative primary surgery for single gland parathyroid adenomas at Georgia Regents Department of Otolaryngology Head and Neck Surgery between January 2009 and April 2013 were retrospectively reviewed. Patient demographic data and preoperative PTH, calcium, ionized calcium, 25-OH-vitamin D, creatinine, and glomerular filtration rate (GFR) levels were recorded, along with postoperative calcium, ionized calcium, and PTH levels. The values from patients with ePTH and normal PTH postoperatively were compared. Results: Of 119 patients meeting inclusion criteria, 30 (25.2%) demonstrated postoperative ePTH with eucalcemia. This group had significantly higher preoperative PTH ( P = .0021) and creatinine ( P = .0065) levels and a lower GFR ( P = .0016) than those with a normal postoperative PTH. The preoperative vitamin D level was not significantly associated with ePTH postoperatively (odds ratio [OR] = 1.56). Preoperative compromised renal function, specifically abnormal GFR (OR = 12.8), was significantly associated with ePTH postoperatively. Conclusions: The postoperative PTH levels remain elevated in 25.2% of patients achieving eucalcemia after surgery for primary hyperparathyroidism. This phenomenon was associated with compromised preoperative renal function. Physicians and patients must be aware of this condition to avoid subjecting patients to unnecessary further intervention.