Pattern of Intraoperative Parathyroid Hormone and Calcium in the Treatment of Tertiary Hyperparathyroidism

Abstract

Objective Tertiary hyperparathyroidism, an autonomous hyperproduction of parathyroid hormone (PTH), has a challenge in its treatment. This study asked whether the intraoperative PTH and calcium drop can confirm the resection of all parathyroid tissues. Study Design Case series with planned data collection. Setting Tertiary referral medical center. Subjects and Methods The study assessed patients with tertiary hyperparathyroidism who were treated at the Hospital of the State University of Campinas from 2007 to 2015. All patients underwent total parathyroidectomy with autotransplantation of parathyroid fragments. PTH and calcium were collected during the preoperative period; at 10, 20, and 240 minutes after resection of the glands; and at 1 year after the procedure. Data were analyzed by analysis of variance and logistic regression analysis with statistical values of P < .05. Results Thirty-five patients were assessed: 17 women (48.57%) and 18 men (51.43%). The percentage of PTH drop was statistically significant at all times, unlike the calcium analysis, but only PTH collected at 20 minutes was able to confirm the removal of all parathyroid tissues ( P = .029). Based on the receiver operating characteristic curve, the 71.2% drop obtained high sensitivity and specificity ( P = .028). Conclusions Treatment success can be predicted by analyzing the decrease of intraoperative PTH and not by calcium. The 71.2% PTH drop at 20 minutes after parathyroidectomy had high sensitivity and specificity to predict surgical cure.

The American Association of Endocrine Surgeons Guidelines for the Definitive Surgical Management of Secondary and Tertiary Renal Hyperparathyroidism

“…356,359 Failure to decline may indicate the presence of ectopic or supernumerary glands. 358,359 Lastly, the rates of persistent and recurrent disease declined when ioPTH was employed during PTX when compared with operations where ioPTH was not used. 340 Recommendation 6-14: The benefits and limitations of ioPTH monitoring in patients with THPT should be understood by all surgeons performing these operations.…”

“…Conversely, other author groups concluded that ioPTH testing impacted the real-time operative care of THPT as ioPTH assays allow for limited rather than subtotal resections in 9% to 20% of patients 356,359. Failure to decline may indicate the presence of ectopic or supernumerary glands 358,359. Lastly, the rates of persistent and recurrent disease declined when ioPTH was employed during PTX when compared with operations where ioPTH was not used 340…”

Parathyroid Glands and Hyperparathyroidism: A General Overview

“…In tertiary HPT, the parathyroid glands become autonomous in the production of PTH, despite the improvement in renal function, observed mainly in post-kidney transplant patients [36]. There is not a sufficient decrease in PTH, which remains in the range of 5-10 times greater than normal.…”

“…Vitamin D levels also tend to normalize, since the absence of kidney damage in the post-transplant patient normalizes the conversion of vitamin D into its active form (calcitriol) and also normalizes the intestinal absorption of calcium. Thus, the mechanisms lead to increased serum calcium concentration [36,37].…”

“…Surgical treatment is indicated due to persistent hypercalcemia, in addition to symptoms that may be associated, such as bone pain, pathological fractures, and intractable pruritus. The surgical approach, as in secondary HPT, can be total parathyroidectomy with autograft of parathyroid fragments in muscle tissue, or subtotal parathyroidectomy [36,54]. The measurement of intraoperative rapid PTH in cases of secondary and tertiary HPT during surgical treatment is the subject of much current discussion, although it is increasingly accepted in order to avoid new approaches due to recurrent or persistent disease [36,51,55,56].…”