PTH Spikes During Surgical Treatment for Secondary and Tertiary Hyperparathyroidism: A Prospective Observational Study.

BACKGROUND: The aim of the present study was to determine whether PTH spikes in renal hyperparathyroidism can interfere with the interpretation of intraoperative PTH monitoring and to determine its frequency and characteristics. METHODS: This was a prospective observational study of consecutive patients who underwent surgical treatment in a single tertiary institution. Patients were divided into two groups: spike and no spike. Patients with secondary and tertiary hyperparathyroidism were analyzed separately. Intraoperative PTH monitoring by venous serial samples: two samples were taken before the excision of the parathyroid gland, and two others were taken after resection. RESULTS: PTH spikes occurred in 23.5% (53 of 226), and their occurrence was similar between secondary and tertiary hyperparathyroidism patients (p = 0.074). The relative PTH spike intensity was higher in transplanted patients than in dialysis patients (55 vs. 20%, p = 0.029). A characteristic of the secondary hyperparathyroidism patients was the highest frequency of surgical failure (23 vs. 7.5%, p = 0.016) and the higher occurrence of supernumerary glands in the spike group (23 vs. 10.3%, p = 0.035). Supernumerary parathyroid was associated with surgical failure [19.1 (6.5-55.7) odds ratio [confidence interval], p < 0.001). In the studies evaluating the diagnostic test validity for patients on dialysis and experiencing spikes, the most significant impacts were in the sensitivity, accuracy, and negative predictive value of the method. CONCLUSIONS: PTH spikes occurred in up to 23.5% of renal hyperparathyroidism surgical treatments and can negatively influence the intraoperative parathyroid hormone monitoring. Regarding the phenomenon of PTH spikes, it is prudent to think about the possibility of a hyperplastic supernumerary gland.

Critical analysis of the intraoperative parathyroid hormone decrease during parathyroidectomy for secondary and tertiary hyperparathyroidism.

BACKGROUND: This study aims to determine whether intraoperative parathyroid hormone monitoring helps to predict early surgical outcomes in patients with renal hyperparathyroidism and evaluate the impact on decision making during surgery. METHODS: A prospective study was conducted. Serial samples of the intraoperative parathyroid hormone were collected; 2 of these were taken before the excision, and 2 were taken after the planned parathyroid resection (10 minutes and 15 minutes). We tested the criterion of an intraoperative parathyroid hormone percentage decay ≥80% of the highest value of the basal samples as a predictor of success. RESULTS: Of the 228 patients, parathyroidectomy achieved success in 92.1%. In patients with secondary hyperparathyroidism, the failure group showed a tendency to stabilize or even increase the intraoperative parathyroid hormone values from the 10-minute measure (577 pg/mL) to the 15-minute measure (535 pg/mL) (P = .903). Conversely, intraoperative parathyroid hormone continued to drop in those with a successful outcome: 245 pg/mL (10 minutes) and 206 pg/mL (15 minutes) (P < .001). The failure group had a significantly lower percentage decay (P < .001) from baseline when compared with the success group. The intraoperative parathyroid hormone influenced the surgical management in up to 7% of the cases. The intraoperative parathyroid hormone dosage method showed an accuracy of 86%, a sensitivity of 88%, and specificity of 67%. CONCLUSION: In patients with renal hyperparathyroidism undergoing parathyroidectomy, the use of intraoperative parathyroid hormone may help to predict an early therapeutic outcome with high sensitivity and accuracy by indicating the operation's success when there is an 80% reduction of baseline intraoperative parathyroid hormone 15 minutes after removal of the enlarged glands, an associated continuous decrease in serum intraoperative parathyroid hormone levels between 10 and 15 minutes, and achievement of plasma target values <500 pg/mL.

Parathyroidectomy in patients with chronic kidney disease: Impacts of different techniques on the biochemical and clinical evolution of secondary hyperparathyroidism.

BACKGROUND: Parathyroidectomy (PTx) decreases the mortality rate of refractory secondary hyperparathyroidism (rSHP) due to chronic kidney disease. A consensus regarding which techniques of PTx are associated with better outcomes is not available. The aims of this study are to evaluate the clinical and laboratory evolution of 49 hemodialysis patients with rSHP who underwent PTx using different techniques. METHODS: Patients underwent subtotal PTx (sub-PTx) or total PTx with autotransplantation (AT) of 45 (PTx-AT45) or 90 parathyroid fragments (PTx-AT90) and were followed for 12 months. We analyzed the expression of proliferating cell nuclear antigen (PCNA), calcium-sensing receptor (CasR), vitamin D receptor (VDR), fibroblast growth factor receptor-1 (FGFR1), sodium-dependent phosphate cotransporter-1 (PIT1), and Klotho in parathyroid glands. RESULTS: Baseline median serum intact parathyroid hormone (iPTH) levels were 1,466 (1,087-2,125) pg/mL; vascular calcification scores correlated with serum iPTH (r = 0.529; P = .002) and serum phosphate levels (r = 0.389; P = .028); and Klotho expression was negatively correlated with serum phosphate levels (r = -0.4; P = .01). After 12 months, serum iPTH and alkaline phosphatase levels were significantly controlled in all groups, as was bone pain. The proportions of patients with serum iPTH levels within the ranges recommended by Kidney Disease: Improving Global Outcomes were similar among the treatment groups. During the hungry bone disease (HBS), patients received 3,786 g (1,412-7,580) of elemental calcium, and a trend toward a positive correlation between the cumulative calcium load at the end of follow up and VC score post-PTx was noted (r = 0.390; P = .06). Two cases evolved to clinically uncontrolled hyperparathyroidism in the sub-PTx group. The expression patterns of PCNA, VDR, CasR, PIT1, FGFR1, and Klotho in parathyroid glands did not correlate with serum systemic iPTH levels or the duration of HBS. CONCLUSIONS: All 3 operative techniques were effective at controlling rSHP, both in clinical and laboratory terms. Neither the quantity nor quality of parathyroid fragments influenced serum systemic iPTH and AT-iPTH levels. The cumulative calcium load appeared to correlate with the VC score and may have affected its progression. The effects of phosphate restriction on Klotho expression in human parathyroid glands and the subsequent decrease in FGF23 resistance must be addressed in further studies.