Quick Intraoperative Parathyroid Hormone Assay: Surgical Adjunct to Allow Limited Parathyroidectomy, Improve Success Rate, and Predict Outcome

Abstract

Intraoperative parathyroid hormone (PTH) assay (QPTH) has made possible less invasive operative approaches in the treatment of primary hyperparathyroidism with stated advantages. When compared to the traditional bilateral neck exploration (BNE), only the targeted, hypersecreting gland is excised, leaving in situ non-visualized but normally functioning parathyroids. The QPTH-guided limited parathyroidectomy (LPX) must be able to identify multiglandular disease (MGD), predict a successful outcome, and have a low recurrence rate. In our series, 421 patients who underwent LPX were compared to 340 undergoing BNE; all operative failures and patients followed for 6 months or longer were included. Operative failure occurred if serum calcium and PTH levels were elevated within 6 months of parathyroidectomy. Multiglandular disease was defined in the LPX group as more than one gland excision guided by QPTH or operative failure after removal of a single abnormal gland; in the BNE group it was defined as excision of more than one enlarged gland. Recurrence was defined as elevated calcium and PTH after 6 months of eucalcemia. Operative failure and MGD rates were compared using chi-squared analysis. The method of Kaplan-Meier and the log-rank test were used to compare recurrence rates. Operative success was seen in 97% of LPX patients and in 94% of the BNE group ( p = 0.02). Multiglandular disease was identified in 3% of LPX patients and 10% of BNE patients ( p < 0.001). There was no statistical difference in the overall recurrence rates ( p = 0.23). The QPTH-guided parathyroidectomy identifies MGD and allows an improved success rate with the same low recurrence rate when compared to the results of BNE.

Current evidence for recommendation of surgery, medical treatment and vitamin D repletion in mild primary hyperparathyroidism

“…These statements were based on a recent large number of operations that showed no obvious differences in the success or complication rates between traditional neck explorations or modern, minimally invasive techniques. Primary parathyroidectomy (PTX) is usually reported to have a cure rate of 95-98% and a complication rate as low as 1-3%, with a serious complication rate far below 1% (41)(42)(43). The operative results reported from centres of excellence, however, may be difficult to obtain for routine clinical practice in non-specialised surgical departments.…”

Bilateral neck exploration in patients with primary hyperparathyroidism and discordant imaging results: a single-centre study

“…However, 24-27% of preoperative imaging results are discordant (6,16) and 12-18% are negative (17,18,19); for these cases, the gold standard for surgery remains bilateral exploration (5). The choice between the treatment strategies of focused parathyroidectomy and bilateral exploration remains a matter of debate (20,21,22,23). However, recent data in the literature suggested that focused parathyroidectomy was less expensive and induced fewer side effects with at least identical remission rates, resulting in a shorter hospital stay (5,24).…”

Current Concepts in the Presentation, Diagnosis and Management of Primary Hyperparathyroidism

“…With a 97% accuracy rate, IoPTH is measured based on a 50% drop from an initial PTH level reading to the level measured 10 min after gland excision. When PTH levels remain elevated after an excision of the suspected gland, a bilateral neck exploration may be necessary to locate the remaining hypersecreting tissue [56,57]. The IoPTH test is also reliable in mild cases, even if PTH is not elevated [59].…”

“…The IoPTH assay is used to determine the appropriateness of a parathyroid tissue resection [56,57]. Numerous criteria have been suggested to confirm the sufficiency of parathyroid resections [58]; however, the most widely accepted is the Miami criterion.…”