Do Intraoperative Total Serum and Ionized Calcium Levels, Like Intraoperative Intact PTH Levels, Correlate with Cure of Hyperparathyroidism?

Secondary parathyromatosis in a patient with normal kidney function: review of diagnostic modalities and approaches to management

OBJECTIVE

To present a patient with secondary parathyromatosis, a rare complication of parathyroidectomy, and to discuss issues currently pertinent to its diagnosis and management.

METHODS

Data were derived from clinical and pathologic observations obtained during patient care.

RESULTS

The index patient developed intractable hyperparathyroidism and hypercalcemia that has persisted after 4 surgical procedures and has remained largely resistant to medication, albeit with partial amelioration with combined bisphosphonate and cinacalcet.

CONCLUSION

Despite the rarity of this difficult complication of parathyroidectomy, its iatrogenic basis emphasizes a need for heightened awareness and caution among surgeons and endocrinologists. Herein we report an instance of intractable secondary parathyromatosis in a patient with normal kidney function, and we review current approaches to diagnosis and management.

Intraoperative calcium monitoring is insufficient to predict the surgical success of parathyroidectomy for primary hyperparathyroidism

PURPOSE

Serum calcium has been suggested to be a surrogate marker for intraoperative monitoring during a parathyroidectomy (PTX) for primary hyperparathyroidism (pHPT). The objective of the present prospective study was to investigate whether serum calcium can be used as an alternative for parathyroid hormone intraoperative monitoring.

METHODS

Intact parathyroid hormone (iPTH), total and ionized serum calcium, total protein (tP), and pH were monitored in parallel in 25 patients during a successful directed PTX for pHPT.

RESULTS

All patients had at least a 50% decrease of iPTH 10 min after PTX. Simultaneously measured total serum calcium (tCa) and ionized serum calcium (iCa) did not correlate with iPTH or pH. However, tCa and iCa levels correlated with changes in tP (r = 0.859; P < 0.001; r = 0.483; P = 0.014). In addition, intraoperative iCa changes correlated with preoperative iCa levels (r = -0.475, P = 0.016). A linear regression analysis for parameters potentially influencing intraoperative tCa and iCa dynamics changes identified tP changes as the only parameter influencing tCa and iCa changes (P < 0.001).

CONCLUSION

Individual short-term intraoperative changes of tCa or iCa are not predictive for successful PTX, as they more likely reflect changes in intraoperative fluid management rather than decreased iPTH.

Significance of monitoring Bio-Intact PTH (1-84) during parathyroidectomy for secondary hyperparathyroidism

BACKGROUND

The Bio-Intact PTH (1-84) assay has recently been developed to specifically measure the intact PTH (1-84) molecule, and in this study we used it to investigate sequential changes in serum Bio-Intact PTH (1-84) levels during parathyroidectomy for secondary HPT.

MATERIAL AND METHODS

The subjects of this study were 70 patients (41 women, 29 men) who underwent parathyroidectomy between April 2002 and March 2005. Ethylene diamine tetraacetic acid serum samples were drawn via a peripheral venous catheter after induction of anesthesia (basal), and at 5, 10, and 30 min after diseased glands excision. Serum active PTH (1-84) was measured by the Bio-Intact PTH (1-84) assay, which is a two-site chemiluminometric assay.

RESULTS

When 4 or more diseased parathyroid glands were removed, the basal of Bio-Intact PTH (1-84) level in patients without persistent HPT (52 cases) was 539 +/- 355 pg/mL. The level of the Bio-Intact PTH (1-84) at 30 min after sufficient parathyroidectomy had decreased to less than 45 pg/mL, whereas the Bio-Intact PTH (1-84) level in patients with persistent HPT at 30 min was greater than 45 pg/mL (3 cases). After removal of three or fewer diseased parathyroid glands (15 cases), the Bio-Intact PTH (1-84) at 30 min in patients without persistent HPT (13 cases) was less than 45 pg/mL. The 2 patients whose the Bio-Intact PTH (1-84) at 30 min was greater than 45 pg/mL underwent reoperation, and residual enlarged parathyroid gland in the neck was removed.

CONCLUSIONS

The Bio-Intact PTH (1-84) level at 30 min after parathyroidectomy seems to be useful for judging whether the parathyroidectomy is complete irrespective of the number of glands removed from patients with secondary HPT. When only three diseased parathyroid glands are removed, the surgeon can decide whether to continue or stop neck exploration according to the level of Bio-Intact PTH (1-84) at 30 min.

[Modifications in intact parathyroid hormone, total serum calcium, and ionized calcium levels in the surgery of primary hyperparathyroidism for single adenoma]

INTRODUCTION

We evaluated total serum calcium (TSC) and ionized calcium (IC) and their correlation with intraoperative intact parathyroid hormone (iPTH) in the surgery of primary hyperparathyroidism in patients with a single adenoma.

MATERIAL AND METHOD

We performed a prospective, blind trial with determination of iPHT, TSC and IC in a cohort of surgical patients (n = 279; 244 were valid for the study) who underwent surgery in the Department of Surgery, Hospital de Cruces, between October 1999 and April 2006. Total calcium, ionic calcium and iPTH were measured in the outpatient department, on admission and intraoperatively (at anesthesia induction and every 5 minutes after surgical excision).

RESULTS

Levels of calcium and iPTH were corrected in 234 (95.9%) patients. iPTH decreased from abnormal preoperative values of 294.43 +/- 286.38 pg/ml to 97.89 +/- 121.01 mg/dl (minute 5), 58.58 +/- 58.37 pg/ml (minute 10), 44.62 +/- 54.77 pg/ml (minute 15), and 38.42 +/- 51.72 pg/ml (minute 20). TSC decreased from preoperative values of 10.93 +/- 1.04 mg/dl to 10.2 +/- 0.97 mg/dl (minute 5), 10.17 +/- 1.00 mg/dl (minute 10), 10.12 +/- 0.98 mg/ml (minute 15), and 10.09 +/- 1.03 mg/ml (minute 20). The results for ionized calcium were as follows: 4.90 +/- 0.63 mg/dl at induction, 4.84 +/- 0.61 mg/dl (minute 5), 4.84 +/- 0.66 mg/dl (minute 10), 4.82 +/- 0.63 mg/dl (minute 15), and 4.82 +/- 0.63 mg/dl (minute 20). Frozen samples were conclusive for parathyroid tissue (19.56 +/- 15.3 after excision).

CONCLUSIONS

Intraoperative total calcium levels may help to predict adequate elimination of parathyroid tissue in primary hyperparathyroidism when intraoperative iPTH is not available. Ionized calcium levels did not show the same decrease.