COULD THE RATE OF DECREASE IN INTRAOPERATIVE PARATHYROID HORMONE LEVEL BE A DETERMINANT OF SURGICAL TECHNIQUE IN TERTIARY HYPERPARATHYROIDISM?

ObjectivesSecondary hyperparathyroidism (sHPT) is a prevalent complication of end stage renal disease in which serious morbid conditions and mortality can be encountered. Although the best solution of this severe problem is renal transplantation, because of the huge demand and limited resources, this cannot be possible most of the time. Initial treatment alternative is medical treatment in patients with sHPT and parathyroidectomy (PTX) should be applied if does not help. Subtotal PTX, total PTX and total PTX together with autotransplantation are the current surgical options preferred for sHPT. Intraoperative parathyroid hormone (IO PTH) monitoring can increase surgical success in sHPT. We aimed to determine the ideal surgical technique and relation of IO PTH monitoring with surgical success in patients with sHPT through our study.MethodsWe analyzed all the data of the 35 patients who had PTX and follow up between January 2001 and December 2021 because of sHPT at General Surgery Department of Akdeniz University Medical Faculty Hospital in retrospective manner.ResultsTwenty-seven of the patients had been applied subtotal PTX while six of the cases had experienced limited surgery and two of them had undergone total PTX. Persistance happened to be present in the follow-up of nine patients and recurrence in one of them. Four persistant and one recurrent cases were present in 23 patients with IO PTH monitoring (78.3% surgical success), while there were persistences in each of the three patients with no IO PTH monitoring (0% success of surgery) (p=0.022). IO PTH monitoring data of nine patients could not be reached. In this study, 20 patients had IO PTH decline of 80% or more (90% surgical success) and three patients had IO PTH decline below 80% (0% surgical success) (p=0.006). Subtotal PTX was applied to 17 (94.1% surgical success) of these 20 patients.ConclusionIn surgical treatment of patients with sHPT, IO PTH monitoring should be maintained and operation should not be finished until 80% or more decline in IO PTH level had been detected. Among the surgical alternatives for sHPT, subtotal PTX appears as an effective and valid method when performed together with IO PTH monitoring, provided that there is a decline in PTH level of 80% or more.

Surgery is the definitive treatment for primary hyperparathyroidism (PHPT). However, surgical outcomes can be affected by numerous factors, some of which are still a matter of debate. We examined cases at the First Affiliated Hospital of Zhejiang University, and assessed the risk factors affecting surgical success and postoperative recurrence. We conducted a retrospective analysis of the clinical data of patients who underwent surgery for PHPT without intraoperative parathyroid hormone (IOPTH) monitoring at the First Affiliated Hospital of Zhejiang University between August 2017 and June 2022. We analyzed the surgical success rates, recurrence rates, and persistent disease rates, and performed univariate and multivariate analyses to identify the risk factors associated with surgical success and postoperative recurrence/persistent lesions. The overall surgical success rate was 97.8%, and the postoperative recurrence rate was 8.2%. Univariate analysis confirmed that a higher level of preoperative parathyroid hormone (PTH) and blood calcium is associated with a lower success rate of surgery (P<0.05). However, the multivariate analysis did not reveal any significance in them. The univariate analysis identified preoperative target organ damage, urolithiasis, and preoperative alkaline phosphatase (ALP), PTH, and phosphorus levels as risk factors for postoperative recurrence/persistent lesions (P<0.05). The multivariate analysis revealed that only the phosphorus level was a significant risk factor for postoperative recurrence/persistent lesions (P<0.05). The receiver operating characteristic (ROC) curve analysis indicated that phosphorus levels below 0.865 mmol/L were associated with a higher incidence of recurrence/persistent lesions, and had a sensitivity of 0.718 and a specificity of 0.67. In PHPT, satisfactory surgical success rates can be achieved without IOPTH monitoring. The blood phosphorus level is a significant predictor of postoperative recurrence or persistent lesions, and thus could guide clinical decision making.

Ectopic mediastinal parathyroid adenoma is rare and is generally managed by surgical resection as a definitive treatment. Intraoperative parathyroid hormone (ioPTH) monitoring is valuable for ensuring the complete removal of a target lesion. However, there is no consensus criteria regarding the utilization of ioPTH for complete resection in patients with ectopic mediastinal parathyroid adenomas. A 65-year-old woman presented with asymptomatic hypercalcemia, and was subsequently diagnosed as having hyperparathyroidism. Radiological imaging displayed a solid mediastinal tumor, suspected to be ectopic mediastinal parathyroid adenoma. Surgical resection was performed together with ioPTH monitoring. Although a transient increase in intact parathyroid hormone (iPTH) level was noted, a 22% decrease in iPTH level compared with the preoperative peak iPTH level was observed 30 minutes after the resection. Intraoperative frozen section diagnosis confirmed complete resection of the ectopic mediastinal parathyroid adenoma. Serum iPTH and calcium levels rapidly decreased postoperatively. The patient was discharged without any complications, and no recurrence was found. We herein report a case of a patient in whom thoracoscopic removal of an ectopic mediastinal parathyroid adenoma using ioPTH monitoring resulted in a successful postoperative outcome. Our present case demonstrates that although ioPTH monitoring is important, it is also crucial to avoid stimulation of the tumor by intraoperative compression and to confirm complete resection by additional modalities, such as by pathological analysis.

Use of intraoperative parathyroid hormone (ioPTH) monitoring during total parathyroidectomy for secondary hyperparathyroidism is common, although its ability to predict long-term normoparathyroid state is not known. Prospective evaluation of 57 consecutive patients undergoing total parathyroidectomy for renal hyperparathyroidism with ioPTH monitoring and follow-up PTH assays were used to categorize the patients into 3 groups: success, adequate biochemical control, and failure. There was no statistically significant difference in percentage reduction of ioPTH between the 3 groups (p = .07), although there was a moderate negative correlation between percentage reduction of ioPTH and percentage reduction of PTH at follow-up (R = 0.57). When used under current guidelines, ioPTH monitoring is of no use in predicting long-term cure for these patients because it does not predict success. Patients that undergo total parathyroidectomy are required to have long-term calcium and PTH assay follow-up because normoparathyroidism cannot be assumed. Using the regression equation calculated, success may be predicted for future patients.

Hyperparathyroidism is a common endocrine disorder that occurs secondary to abnormal parathyroid gland functioning. Depending on the type of hyperparathyroidism, surgical extirpation of hyperfunctioning parathyroid glands can be considered for disease cure. Intraoperative parathyroid hormone (IOPTH) monitoring improves outcomes in patients undergoing surgery for primary hyperparathyroidism, but studies are needed to characterize its institutional adoption and its role in surgery for secondary and tertiary hyperparathyroidism, as these entities can be difficult to cure. Hence, we will perform a cross-sectional survey study of surgeon rationale, operational details, and barriers associated with IOPTH monitoring adoption across North America. We will utilize a convenience sampling technique to distribute an online survey to head and neck surgeons and endocrine surgeons across North America. This survey will be distributed via email to three North American professional societies (i.e., Canadian Society for Otolaryngologists-Head and Neck Surgeons, American Head and Neck Society, and American Association of Endocrine Surgeons). The survey will consist of 30 multiple choice questions that are divided into three concepts: (1) participant demographics and training details, (2) details of surgical adjuncts during parathyroidectomy, and (3) barriers to adoption of IOPTH. Descriptive analyses and multiple logistic regression will be used to evaluate the impact of demographic, institutional, and training variables on the use of IOPTH monitoring in surgery for all types of hyperparathyroidism and barriers to IOPTH monitoring adoption. Ethics approval was obtained by the Hamilton Integrated Research Ethics Board (2024-17173-GRA). These findings will characterize surgeon and institutional practices with regards to IOPTH monitoring during parathyroid surgery and will inform future trials aimed to optimize the use of IOPTH monitoring in secondary and tertiary hyperparathyroidism.

BackgroundMinimally invasive parathyroidectomy (MIP) is the preferred approach to primary hyperparathyroidism (PHPT) when a single adenoma can be localized preoperatively. The added value of intraoperative parathyroid hormone (IOPTH) monitoring remains debated because its ability to prevent failed parathyroidectomy due to unrecognized multiple gland disease (MGD) must be balanced against assay-related costs. We used a decision tree and cost analysis model to examine IOPTH monitoring in localized PHPT.MethodsLiterature review identified 17 studies involving 4,280 unique patients, permitting estimation of base case costs and probabilities. Sensitivity analyses were performed to evaluate the uncertainty of the assumptions associated with IOPTH monitoring and surgical outcomes. IOPTH cost, MGD rate, and reoperation cost were varied to evaluate potential cost savings from IOPTH.ResultsThe base case assumption was that in well-localized PHPT, IOPTH monitoring would increase the success rate of MIP from 96.3 to 98.8%. The cost of IOPTH varied with operating room time used. IOPTH reduced overall treatment costs only when total assay-related costs fell below $110 per case. Inaccurate localization and high reoperation cost both independently increased the value of IOPTH monitoring. The IOPTH strategy was cost saving when the rate of unrecognized MGD exceeded 6% or if the cost of reoperation exceeded $12,000 (compared with initial MIP cost of $3733). Setting the positive predictive value of IOPTH at 100% and reducing the false-negative rate to 0% did not substantially alter these findings.ConclusionsInstitution-specific factors influence the value of IOPTH. In this model, IOPTH increased the cure rate marginally while incurring approximately 4% additional cost.

Intraoperative parathyroid hormone (ioPTH) monitoring (IPM) is vital to minimally invasive parathyroidectomy. Techniques vary in assay sampling, potentially affecting predictive accuracy of operative success. Initial guidelines were established using peripheral sites, but central sites may be preferred or necessary when peripheral access is not feasible. We hypothesize that changing collection sites from preexcision peripheral sites to postexcision central sites would not affect IPM accuracy. Analysis of 64 consecutive patients who underwent parathyroidectomy for primary hyperparathyroidism was undertaken. PTH assays were collected simultaneously from a peripheral vein (PV) and central vein (CV) preexcision and at a 10-min interval after initial parathyroid excision. IPM success was defined as PTH decrease ≥50% 10min after initial excision. Predictive accuracy was determined by the need to resect another abnormal gland and biochemical normalization in the postoperative clinic. Receiver operating characteristic (ROC) method with area under the curve (AUC) compared diagnostic accuracy of different assay approaches. Centrally, a statistically higher mean pre- and postexcision ioPTH of 391pg/ml and 58pg/ml was found compared with peripheral means of 156pg/ml and 49pg/ml, respectively (p<0.001). The AUC when changing from a PV preexcision to a CV postexcision ioPTH was 0.89, comparable to AUC for peripheral or central assay collections alone (AUC=0.83 and 0.85, respectively). This study suggests that altering collection sites does not alter assay validity. In cases where peripheral sampling is compromised, changing from a peripheral to central sites will not likely alter the predictive accuracy of IPM significantly.

Parathyroidectomy outcomes according to operative approach

Surgical resection is the only curative therapy for patients with primary hyperparathyroidism (1HPT). Although cure rates of parathyroidectomy are generally high, failure is most often due to unrecognized multigland disease (MGD), which compromises 15-20% of patients with 1HPT. The use of intraoperative PTH (ioPTH) monitoring is well established for single-gland disease. Controversy remains over the utility of ioPTH in MGD, with concern for false-positive results leading to prematurely concluding the operation and leaving behind abnormal parathyroid tissue, risking future recurrence. The aim of this study was to determine the utility of ioPTH monitoring for MGD. Between November 2000 and March 2008, data were prospectively collected on 755 patients with 1HPT who underwent parathyroidectomy. PTH samples were collected pre-incision, and then at 5, 10, and 15 min after excision of suspected abnormal parathyroid gland(s). Surgical cure was defined as a drop of greater than 50% in PTH level. Patients were clinically cured if they became normocalcemic postoperatively and remained so for 6 months. The data were analyzed to determine how accurately ioPTH predicted success or failure of parathyroidectomy. Of the 755 patients, 163 (21.5%) were found to have MGD on pathology. Intraoperative PTH monitoring was used in 161 of these cases. In 146/161 cases (90.7%), the ioPTH level fell by at least 50% after removal of all suspected abnormal glands. All of these patients (100%) remained normocalcemic postoperatively. In 15/161 cases (9.3%), the PTH level did not fall by >50%. For 11/15 cases (73%), patients remained hypercalcemic postoperatively or had recurrence. However, in the remaining four cases, the patients became normocalcemic postoperatively despite failure of the PTH to fall by >50%. In each of these patients, PTH levels fell by 40-50%. ioPTH monitoring accurately predicted success or failure of parathyroidectomy in 97.5% (157/161) of patients with MGD. A fall of ioPTH by >50% can be used as a highly accurate predictor of cure in patients with MGD. Therefore, ioPTH monitoring is a very useful tool in patients with 1HPT and MGD.

Background Surgery is the only curative treatment option for primary hyperparathyroidism (PHPT). The intraoperative parathormone (IOPTH) monitoring is recommended to confirm that all pathological glands have been removed. This study aimed to evaluate the effect of IOPTH monitoring on the surgical success of parathyroidectomy performed for PHPT. Methods The demographic, biochemical, operative and pathological data of patients who underwent parathyroidectomy for PHPT in a single institute over a three-year period were retrospectively analyzed. Results The total number of patients included in the study was 182. The IOPTH monitoring had been performed in 92 patients (50.5%). The IOPTH monitoring had a clinical accuracy of 89.2%, sensitivity of 89.8%, and specificity of 75%. The rate of surgical success was 95.7% in the group with IOPTH monitoring and 91.1% in the group without this monitoring (p = .21). Of the 40 patients who underwent minimally invasive parathyroidectomy (MIP), 25 patients had IOPTH monitoring, and the surgery was successful for all these patients (100%). Surgical success was achieved in 14 (93.3%) patients who underwent MIP without IOPTH monitoring (p = .37). Conclusion The IOPTH monitoring is a reliable test with high accuracy. The lack of IOPTH monitoring may result in lower than acceptable surgical success rates. Even though preoperative localization studies are compatible with surgical findings, the IOPTH monitoring should also be undertaken, especially in patients scheduled for MIP for PHPT.

Intraoperative parathyroid hormone (IOPTH) monitoring during surgery for primary hyperparathyroidism (PHPT) could improve cure rate and simplify current care pathways. This study assesses the performance of US, MIBI and IOPTH monitoring and their impact on outcomes and perioperative strategy. This is a retrospective study of a prospectively maintained database of patients who underwent parathyroidectomy guided by preoperative US, MIBI and IOPTH monitoring. Test performance (sensitivity, specificity, PPV, NPV, accuracy) and IOPTH added value (percentage of patients in whom test contributed to achieving cure) were calculated. A total of 617 patients (median age 59years, 75% females), 603 (97.7%) of them cured, were included in analysis. Sensitivity of US was higher than MIBI (78.2% vs 70%, P<0.05), but both were inferior to IOPTH (98.6%, P<0.05). US and MIBI were more sensitive at detecting single gland disease (SGD) than multigland disease (MGD) (85% vs 55% and 77.5% vs 45.5%, respectively, P<0.05), while IOPTH performed well in both situations (98.8% vs 96.7%, P>0.05). In 41 patients with incorrect US predictions, MIBI gave correct result only in 12 (29.3%) cases, while IOPTH gave correct predictions in all but one patient (97.6%). Minimally invasive parathyroidectomy (MIP) was completed in 409 patients, with a similar completion rate regardless whether both or one scan was positive. IOPTH added value was significant in whole cohort (14%) and in subgroups of patients with concordant vs discordant scans, minimally invasive vs conventional surgery, and initial vs reoperative surgery. Intraoperative parathyroid hormone monitoring is more accurate at predicting cure than US and MIBI are at identifying abnormal glands in patients undergoing parathyroidectomy for PHPT and significantly contributes to cure rate in range of clinical scenarios. This implies that its routine use could facilitate successful surgery in patients with single positive imaging and increase number of MIPs while maintaining high cure rate.

Point-of-care (POC) testing, which provides quick test results in near-patient settings with easy-to-use devices, has grown continually in recent decades. Among near-patient and on-site tests, rapid intraoperative and intra-procedural assays are used to quickly deliver critical information and thereby improve patient outcomes. Rapid intraoperative parathyroid hormone (ioPTH) monitoring measures postoperative reduction of parathyroid hormone (PTH) to predict surgical outcome in patients with primary hyperparathyroidism, and therefore contributes to the change of parathyroidectomy to a minimally invasive procedure. In this review, recent progress in applying ioPTH monitoring to patients with secondary and tertiary hyperparathyroidism and other testing areas is discussed. In-suite cortisol monitoring facilitates the use of adrenal vein sampling (AVS) for the differential diagnosis of primary aldosteronism and adrenocorticotropic hormone (ACTH)-independent Cushing syndrome. In clinical and psychological research settings, POC testing is also useful for rapidly assessing cortisol in plasma and saliva samples as a biomarker of stress. Careful resource utilization and coordination among stakeholders help to determine the best approach for implementing cost-effective POC testing. Technical advances in integrating appropriate biosensors with microfluidics-based devices hold promise for future real-time POC cortisol monitoring.

Characterizing the operative findings and utility of intraoperative parathyroid hormone (IOPTH) monitoring in patients with normal baseline IOPTH and normohormonal primary hyperparathyroidism

Role of intra-operative parathyroid hormone (IOPTH) monitoring during parathyroidectomy for primary hyperparathyroidism (PHPT) has long been debated. Our main goal was to investigate the cure rates of parathyroidectomy for primary hyperparathyroidism with and without IOPTH monitoring. Our secondary goal was to investigate if operating room time can be saved when IOPTH monitoring is not used. A retrospective analysis of patients who underwent parathyroidectomy for PHPT due to a single adenoma between 2004 and 2019 was performed. Cure rates and operating room time were compared. 423 patients were included. IOPTH was used in 248 patients (59%). Four patients were not cured, two from each group, with no significant difference between the groups (98.8% vs. 99.1%, p = 0.725). Surgery time was significantly longer in the IOPTH group, p < 0.001. There is no advantage for using IOPTH during parathyroidectomy in suitable clinical settings. The procedure may be safely performed without IOPTH while achieving non-inferior success rates and reducing operative time.

Parathyroidectomy for primary hyperparathyroidism: A retrospective analysis of localization, surgical characteristics, and treatment outcomes