Tertiary Hyperparathyroidism: Why the Delay?

Abstract

To evaluate the reason for delay of surgical referral in tertiary hyperparathyroidism (THPT) and its impact on renal allograft function. Persistent hyperparathyroidism after renal transplant has been shown to negatively impact allograft function, yet referral for definitive treatment of THPT is often delayed. A retrospective review was performed of patients undergoing parathyroidectomy for THPT (n = 38) at a single institution from May 2016 to June 2018. The first elevated serum calcium after transplant and time to referral for parathyroid surgery were recorded. Baseline creatinine post-transplant and the most recent creatinine level were used to assess allograft function. Thirty-eight patients were included, with mean age 53 ± 2 years and 66% male. Mean preoperative calcium and parathyroid hormone were 10.8 ± 0.1 mg/dL and 328 ± 48 pg/mL, respectively. THPT after renal transplant was diagnosed at a median of 15 days (range of 1-4892 days). Median time to parathyroidectomy referral was 320 days (range 16-6281 days). In over 50% of patients, the cited reason for referral to an endocrine surgeon was difficulty with cinacalcet - either cost, poor calcium control, and poor compliance or tolerance. In comparing renal function between patients referred early (<278 days, n = 19) versus later (>278 days, n = 19) for parathyroidectomy, those referred early had an improvement in creatinine (27.6% vs -5%, P = 0.007). Patients with THPT wait approximately a year, on average, before referral to an endocrine surgeon for curative parathyroidectomy; earlier referral was associated with improvement in serum creatinine.