Utilization of Ultrasound for Management of Surgical Intervention of Secondary Hyperparathyroidism and Prolonged Hypocalcemia Post-Parathyroidectomy

Abstract

Objective: To evaluate the application of ultrasound (US) for the surgical intervention in patients with moderate and severe secondary hyperparathyroidism (SHPT), and to identify the risk of prolonged hypocalcemia after parathyroidectomy (PTX). Methods: A consecutive series of moderate and severe SHPT patients (n = 64) underwent ultrasound evaluation of parathyroid glands. Among the 64 patients who received 6-month medication therapies, ten patients with parathyroid hormone (PTH) 300~500 pg/mL were excluded from the study while 32 patients unresponsive to medication therapy (PTH > 500 pg/mL) received surgical interventions and 22 patients with PTH < 300 pg/mL received medication treatment alone. The correlations between the number, location, volume, sonographic features of parathyroid glands (PTGs), laboratory examinations, the duration of dialysis and the surgical necessity were analyzed. Total parathyroidectomy with synchronous auto-transplantation (PTX + AT) was performed in the surgical group. In both the surgical and medication group, patients with hyper-vascularity of the PTGs dominated (≥50%) were classified as a hyper-vascular subgroup, and the others as a hypo-vascular subgroup. The differences of post-operative calcium (Ca2+) levels and the incidence of prolonged hypocalcemia between hyper- and hypo- vascular subgroups were assessed. Results: Sonographic evaluations revealed that the numbers of detectable PTGs were higher in the surgical group than that of the medication group (p < 0.05). The detection of supernumerary PTGs was higher in the surgical group than that in the medication group (13/121, 10.7% vs. 2/71, 2.8%, p < 0.05). Baseline PTH, >2 detectable PTGs, detection of supernumerary PTGs, patients with hyper-vascular, and the duration of dialysis were positively associated with the necessity of surgical intervention. For patients in the hyper-vascular subgroup, the serum Ca2+ level was lower than that in the hypo-vascularity subgroup (p < 0.01). Conclusion: Ultrasonic features can provide useful information for management of surgical intervention of SHPT and prediction of the risk of prolonged hypocalcemia after PXT.

Keywords

• |secondary hyperparathyroidism|ultrasound|total parathyroidectomy|auto transplantation|hypocalcemia