A "defined baseline" in PTH monitoring increases surgical success in patients with multiple gland disease

Findings of pilot study following the implementation of point of care intraoperative PTH assay using whole blood during surgery for primary hyperparathyroidism

Objective

To report findings of pilot study using a novel point of care (POC) intraoperative parathyroid hormone (IOPTH) assay for parathyroid hormone (PTH) using whole blood during surgery for primary hyperparathyroidism (PHPT).

Methods

Patients undergoing surgery for primary hyperparathyroidism from March to November 2022 where intraoperative PTH assay was performed using the NBCL CONNECT IOPTH and the laboratory PTH assay were included (group 1). The biochemistry results were reviewed to determine concordance between NBCL and lab PTH values and diagnostic test parameters of the NBCL CONNECT assay. 'In-theatre' times were then compared with a historical cohort (group 2) where the lab-based IOPTH assay alone was used.

Results

Of the 141 paired samples in group I, correlation between NBCL and the lab assay was high (rho=0.82; p<0.001). PTH levels using the NBCL assay dropped satisfactorily (>50% of the basal or 0 min sample; whichever was lower - i.e. positive test) in 23 patients; giving a positive predictive value of 100%. Of the 9 patients that did not demonstrate a drop, two were true negative (negative predictive value of 22%) leading to cure after excision of another gland. Group 1 (150 mins) had a significantly shorter 'in-theatre' time compared to group 2 (167 mins) (p=0.007); despite much higher use of near infra-red autofluorescence (NIRAF) (72% vs 11.6% in group I and 2 respectively).

Conclusion

The NBCL CONNECT POC IOPTH assay gives comparable results to lab based PTH assays and can be performed without need for a centrifuge or qualified technicians. Surgeons, however, need to be aware of the potential for false-negative results.

Treatment for secondary hyperparathyroidism focusing on parathyroidectomy

Secondary hyperparathyroidism (SHPT) is a major problem for patients with chronic kidney disease and can cause many complications, including osteodystrophy, fractures, and cardiovascular diseases. Treatment for SHPT has changed radically with the advent of calcimimetics; however, parathyroidectomy (PTx) remains one of the most important treatments. For successful PTx, removing all parathyroid glands (PTGs) without complications is essential to prevent persistent or recurrent SHPT. Preoperative imaging studies for the localization of PTGs, such as ultrasonography, computed tomography, and 99mTc-Sestamibi scintigraphy, and intraoperative evaluation methods to confirm the removal of all PTGs, including, intraoperative intact parathyroid hormone monitoring and frozen section diagnosis, are useful. Functional and anatomical preservation of the recurrent laryngeal nerves can be confirmed via intraoperative nerve monitoring. Total or subtotal PTx with or without transcervical thymectomy and autotransplantation can also be performed. Appropriate operative methods for PTx should be selected according to the patients' need for kidney transplantation. In the case of persistent or recurrent SHPT after the initial PTx, localization of the causative PTGs with autotransplantation is challenging as causative PTGs can exist in the neck, mediastinum, or autotransplanted areas. Additionally, the efficacy and cost-effectiveness of calcimimetics and PTx are increasingly being discussed. In this review, medical and surgical treatments for SHPT are described.

Primary Hyperparathyroidism and Intraoperative Parathyroid Hormone Monitoring: Application of a Modified Interpretation in Patients With "Parathyroid Hormone Spikes"

INTRODUCTION

Intraoperative parathyroid hormone (PTH) spikes occur in up to 30% of patients during surgery for primary hyperparathyroidism. This can lead to a prolonged PTH decline and cause difficulties in using current interpretation criteria of intraoperative PTH monitoring. The aim of this study aim was to evaluate an alternative interpretation model in patients with PTH spikes during exploration.

METHODS

1035 consecutive patients underwent surgery for primary hyperparathyroidism in a single center. A subgroup of patients with intraoperative PTH spikes of >50 pg/mL were selected (n = 277; 27.0%). The prediction of cure applying the Miami and Vienna criteria was compared with a decay of ≥50% 10 min after excision of the enlarged parathyroid gland using the "visualization value" (VV; =PTH level immediately after visualization of the gland) as basal value. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were calculated.

RESULTS

Using the VV, sensitivity was 99.2% (Vienna 71.0%; Miami 97.7%), specificity was 18.2 (Vienna 63.6%; Miami 36.4%), and accuracy was 92.8 (Vienna 70.4%; Miami 92.8%). Of 255 single-gland disease patients, 72 were identified correctly as cured by applying the VV (P < 0.001), yet 10 of 22 patients with multiple-gland disease were missed compared with the Vienna Criterion (P = 0.002). The comparison with the Miami Criterion showed that six more patients were correctly identified as cured (P = 0.219), whereas four patients with multiple-gland disease were missed (P = 0.125).

CONCLUSIONS

Using the VV as a baseline in patients with intraoperative PTH spikes may prove to be an alternative and therefore can be recommended. However, if the VV is higher than the preexcision value, it should not be applied.

Surgery for primary hyperparathyroidism

Primary hyperparathyroidism (PHPT) is a hypercalcemic disorder that occurs when one or more parathyroid glands produces excessive parathyroid hormone (PTH). PHPT is typically treated with surgery, and it remains the only definitive therapy, whose techniques have evolved over previous decades. Advances in preoperative localization exams and the intraoperative PTH monitoring have become the cornerstones of recent parathyroidectomy techniques, as minimally invasive techniques are appropriate for most patients. Nevertheless, these techniques, are not suitable for PHPT patients who are at risk for multiglandular disease, especially in those who present with familial forms of PHPT that require bilateral neck exploration. This manuscript also explores other conditions that warrant special consideration during surgical treatment for PHPT: normocalcemic primary hyperparathyroidism, pregnancy, reoperation for persistent or recurrent PHPT, parathyroid carcinoma, and familial and genetic forms of hyperparathyroidism.

The value of intraoperative parathyroid hormone monitoring in patients with primary hyperparathyroidism and varying baseline parathyroid hormone levels

BACKGROUND

When applying intraoperative parathyroid hormone monitoring (IOPTH) to patients with primary hyperparathyroidism (PHPT), there are established criteria predicting biochemical cure in patients with basal parathyroid hormone (PTH) levels in the medium range (100-400 pg/ml); however, there is a challenge concerning patients with low (less than 100 pg/ml) or high (more than 400 pg/ml) basal PTH levels. The aim of this study was to investigate the value of the 'Vienna criterion' applied during IOPTH in patients with PHPT and various basal PTH concentrations.

METHODS

Consecutive patients between 1999-2009 with a biochemical diagnosis of PHPT who underwent surgical parathyroidectomy were included. Based on preoperative PTH levels they were divided into three groups: group 1 (low) (<100 pg/ml), group 2 (medium) (100-400 pg/ml) and group 3 (high) (>400 pg/ml) basal PTH. PTH was measured at the start of the operation, when the gland was excised and then at 5, 10 and 15 min after. Calcium and PTH levels were measured at 7 days and 12 months postoperatively. Sensitivity, specificity, positive and negative predictive value, as well as accuracy of IOPTH were calculated for the different groups postoperatively.

RESULTS

675 patients with PHPT were analysed. Sensitivity and specificity were 83.7 per cent and 66.7 per cent in group 1 (n = 187), 90.7 per cent and 69.2 per cent in group 2 (n = 433), and 94.4 per cent and 100 per cent in group 3 (n = 55) to predict cure. Preoperative creatinine (p = 0.002) showed significant statistical difference between the groups but was not related to intraoperative PTH decline. At 12 months follow-up normocalcaemia was documented in 98.9 per cent in group 1, 99.0 per cent group 2, and 98.0 per cent of group 3 patients.

CONCLUSION

Normocalcaemia was predicted intraoperatively by applying the 'Vienna criterion' in 98 to 100 per cent and was confirmed after 12 months follow-up in up to 99.0 per cent of patients. Low specificity and a high false-negative rate in patients with low basal PTH show that other criteria might be better suited for this group.

Diagnosis of Ectopic Intrathyroidal Parathyroid Adenoma with Nodular Goiter by 18F Fluorocholine: A Case Report

The occurrence of ectopic intrathyroidal parathyroid adenoma (EPTA) is very rare, which causes some difficulties in diagnosis and complicates treatment. In addition, the occurrence of EPTA with nodular goiter (NG) is rare, which makes diagnosis difficult and requires the assistance of clinical evidence, imaging data, and cytological examination results. Therefore, we present a patient with a final diagnosis of ETPA with NG.

Interpretation of intraoperative parathyroid hormone monitoring according to the Rome criterion in primary hyperparathyroidism

Intraoperative parathyroid hormone dosage allows real-time monitoring of the decrease in PTH levels during parathyroidectomy and verify procedure's efficacy. Currently, none of the interpretative criteria used has absolute accuracy. The aim of this study is to evaluate diagnostic accuracy of the Rome criterion verifying diagnostic significance of the individual assays. A total of 205 patients with primary hyperparathyroidism from a single adenoma were retrospectively evaluated and monitored with baseline PTH, PTH at 10 min and PTH at 20 min after adenoma excision. The accuracy of the latter two assays compared with baseline was compared by ROC curves. In addition, was evaluated the influence on these data of localization diagnostics (ultrasounds and scintigraphy), definitive histology, and type of surgery performed. The ratio of 20-min sampling to baseline in the Rome criterion showed highest diagnostic significance. This finding was not influenced by the type of surgery performed, definitive histologic examination, or intraoperative localization of the adenoma. The Rome criterion has shown its high reliability in detecting persistence. The ratio of sampling at 20 min to baseline is by far the best performing. Further studies are needed to evaluate whether sampling at 10 min after adenoma excision can be considered not mandatory.

Accessing the influence of 99mTc-Sesta-MIBI-positive thyroid nodules on preoperative localisation studies in patients with primary hyperparathyroidism

Purpose

Curative treatment for primary hyperparathyroidism (PHPT) is parathyroidectomy (PTX) with removal of the hyperfunctioning gland(s). In an endemic goitre region, 35–78% of PHPT patients show concomitant thyroid disease. This study aimed to evaluate if ^99mTc-sestamibi (MIBI)-positive thyroid nodules decrease sensitivity in regard to localising the hyperfunctioning parathyroid gland(s) in PHPT patients.

Methods

Within 5 years, 497 consecutive patients with biochemically proven PHPT were included in this study. The data was analysed retrospectively.

Results

In total, 198 patients underwent PTX with thyroid surgery and 299 patients underwent sole PTX. Sensitivity of MIBI scan for PTX with and without thyroid surgery was 72.1% and 73.6%, respectively. A statistically significant difference in sensitivity of ultrasound for PTX with and without thyroid surgery (57.0% and 70.9%, respectively) was observed (p = 0.029). Thyroid nodule histology did not have a significant effect on the MIBI scan. Unilateral neck exploration (UNE) was performed in 110 patients and bilateral neck exploration (BNE) in 177 patients. The probability of surgical conversion from UNE to BNE due to incorrect localisation was 1.733 times higher in patients with thyroid nodules.

Conclusions

Concomitant benign thyroid nodules did not influence MIBI sensitivity. No correlation between thyroid carcinoma and MIBI uptake was determined. However, MIBI detection of thyroid malignancy is important in patients initially being considered for minimal invasive parathyroidectomy. Sensitivity and positive predictive value of ultrasound were significantly lower in patients with thyroid nodules. The probability of conversion from UNE to BNE due to incorrect localisation was 1.733 times higher in patients with thyroid nodules.

Diagnostic Accuracy of Intraoperative Intact Parathyroid Hormone Monitoring for Surgical Outcomes of Secondary Hyperparathyroidism

BACKGROUND Intraoperative intact parathyroid hormone (IO-iPTH) monitoring has not reached a consensus in predicting surgical outcomes of secondary hyperparathyroidism. Here, we explore the predictive effect of IO-iPTH monitoring on surgical outcomes of secondary hyperparathyroidism as a potentially effective standard. MATERIAL AND METHODS We enrolled 119 patients who underwent total parathyroidectomy with autotransplantation from January 2016 to August 2019. Intact parathyroid hormone (iPTH) levels were tested 1 day before surgery (iPTHpre), 10 min after glands resection (iPTH10min), and 1 and 7 days after the operation (iPTHd1, iPTHd7). According to iPTHpre levels, patients were divided into a <2000 pg/ml group and a ≥2000 pg/ml group, and the cutoff values were compared. In patients with successful parathyroidectomy, the value of iPTHpre minus iPTH10min (iPTHdec) and relative-iPTH10min were compared between groups. RESULTS Using cutoff values, the predictive criterion was defined as iPTH10min ≤314.5 pg/ml or relative-iPTH10min ≤12.4%. In the iPTHpre ≥2000 pg/ml group, iPTH10min had a higher predictive value (318 pg/ml vs 218 pg/ml) whereas relative-iPTH10min had a lower predictive value (12.1% vs 20.3%). In patients with successful PTX, the iPTHdec value of the iPTHpre ≥2000 pg/ml group was significantly higher than that of the <2000 pg/ml group. Additionally, the relative-iPTH10min was significantly lower in the ≥2000 pg/ml group than in the <2000 pg/ml group. CONCLUSIONS An intraoperative predictive criterion of iPTH10min ≤314.5 pg/ml or relative-iPTH10min ≤12.4% is associated with effectively predicting surgical success of secondary hyperparathyroidism. The predictive value is affected by iPTHpre level; therefore, a variable prediction standard based on iPTHpre levels shall be established.

Surgical outcome after focused parathyroidectomy: experience from a tertiary care centre in North India

&lt;b style=&quot;color: #075541&quot;&gt; Introduction:&lt;/b&gt; Focused parathyroidectomy is the gold standard treatment for primary hyperparathyroidism (PHPT) due to single gland disease with a comparable success rate as that of conventional four gland exploration. It is also associated with fewer surgical complications. Despite these benefits, there is still controversy about the high recurrence following the focused approach. &lt;/br&gt; &lt;/br&gt; &lt;b style=&quot;color: #075541&quot;&gt;Aim:&lt;/b&gt; The aim was to analyse our experience regarding the success rate of focused parathyroidectomy for PHPT. &lt;/br&gt; &lt;/br&gt; &lt;b style=&quot;color: #075541&quot;&gt;Methods:&lt;/b&gt; This was a retrospective analysis of 192 patients of PHPT between January 2017 and August 2020 who underwent focused parathyroidectomy without intraoperative parathormone analysis, and had a minimum follow up of six months. Demographic profile, biochemical (pre and postoperative), radiological, operative and histological detail of all patients were recorded. Parathyroidectomy was considered curative if the patient maintained normal serum calcium and parathormone (PTH) levels six months after surgery. Persistent hyperparathyroidism was considered if hypercalcemia or high PTH levels persisted, or recurrent disease when a patient had rising serum calcium and / or PTH levels six months after curative parathyroidectomy. &lt;/br&gt; &lt;/br&gt; &lt;b style=&quot;color: #075541&quot;&gt;Results:&lt;/b&gt; No patient had pain and wound-related complications after parathyroidectomy. Two patients had voice change in the immediate postoperative period which recovered subsequently; no patient had documented vocal cord paralysis. The persistent disease was present in two patients; both required neck exploration. Five patients had recurrence of PHPT within six months of parathyroidectomy; all of them had hyperplasia on the final biopsy. The overall cure rate was 97.92%. &lt;/br&gt; &lt;/br&gt; &lt;b style=&quot;color: #075541&quot;&gt;Conclusion:&lt;/b&gt; Therefore, we propose focused surgery for sporadic PHPT should be considered as a preferred treatment with acceptable recurrence rate and surgical complications.&lt;/br&gt; &lt;/br&gt; &lt;b style=&quot;color: #075541&quot;&gt;KEYWORDS:&lt;/b&gt;focused parathyroidectomy, parathyroidectomy, primary hyperparathyroidism.

Intra-operative parathyroid hormone evaluation is superior to frozen section analysis in parathyroid surgery

BACKGROUND

Surgery is currently the only treatment option for patients with primary hyperparathyroidism (PHPT). Recently, minimally invasive parathyroidectomy (MIP) has begun to replace traditional bilateral neck exploration (BNE).

OBJECTIVE

The aim of this study is to compare the results of parathyroidectomies performed in our hospital over the past decade that were guided by intra-operative parathyroid hormone (IOPTH) sampling or frozen section (FS) analysis.

MATERIAL AND METHODS

Data on 697 patients who underwent parathyroidectomies in the Department of Endocrine Surgery, Dokuz Eylul University between January 2005 and 2018 were included in this study. Patients with malignancies other than thyroid papillary microcarcinoma and parathyroid cancer were excluded from the study.

RESULTS

The concomitant use of neck ultrasound (US) and technetium 99m Sestamibi (^99mTc MIBI) scintigraphy successfully localized the hyperfunctioning parathyroid glands in nearly 96% of cases. As compared with the IOPTH group, the operation time was longer in the FS group (p < 0.001), and the need for postoperative calcium (Ca) supplementation was higher (p < 0.001). The duration of hospitalization (days) was significantly higher in the FS group (4.2 ± 3.4 vs. 2.6 ± 1.9) as compared with that in the IOPTH group (p < 0.001). In addition, the recurrence rate in the FS group was significantly higher than that in the IPOTH group (p = 0.002).

CONCLUSION

IOPTH sampling is a safe and effective method when performed by experienced surgeons and with appropriate preoperative screening. This study emphasizes that IOPTH sampling. We believe that the success in parathyroid surgery is due to three factors: correct indication, accurate localization and experienced surgeon.

Influence of common clinical variables on intraoperative parathyroid hormone monitoring during surgery for primary hyperparathyroidism

BACKGROUND

Intraoperative monitoring of parathyroid hormone (IOPTH) is a reliable method of predicting the cure of primary hyperparathyroidism (PHPT). The aim of this study is to assess whether common clinical variables (CCV) frequently encountered in patients with PHPT may affect the magnitude of PTH drop or the likelihood of patients meeting the intraoperative cure criterion.

DESIGN

Patients who were surgically cured from PHPT caused by single gland disease (SGD) and had full IOPTH protocol (4 measurements) were stratified according to age, gland weight, renal function, vitamin D status and severity of hypercalcemia. The percentage of IOPTH drop and the frequency of patients who had true positive IOPTH test results were compared among groups.

RESULTS

762 patients had surgery for PHPT, of whom 746 were (98%) cured. Of these 746 patients, 511 who had SGD and a full IOPTH protocol were included in this study. The median IOPTH drop was significantly higher among younger patients, those with severe hypercalcaemia at 5, 10, 15 min after gland excision, giant glands (at 5-min only), patients with vitamin D deficiency (at 10, 15 min), and those with normal renal function (at 15 min only). The likelihood of the patients meeting the intraoperative cure criterion was not significantly affected among the groups except in patients with mild hypercalcaemia, who were significantly less likely to have 50% IOPTH drop than those with severe hypercalcaemia at all time points. The frequency of mildly hypercalcaemic patients who met cure criterion was significantly improved by extending measurement to 15 min.

CONCLUSIONS

IOPTH monitoring has the ability to mitigate the variability of IOPTH kinetics associated with most clinical variables. Mildly hypercalcemic patients in particular may benefit from waiting for 15-min measurement before any surgical decision is made.

The role of intraoperative parathyroid hormone (IOPTH) determination for identification and surgical strategy of sporadic multiglandular disease in primary hyperparathyroidism (pHPT)

Intraoperative PTH monitoring (IOPTH) made minimally invasive parathyroidectomy in patients with primary HPT possible. However, with the increasing accuracy of preoperative localization studies there is a growing discussion if IOPTH is necessary in patients with localized single gland disease (concordant preoperative localization studies). Different interpretation criteria have been developed - each with their particular advantages and disadvantages, but the "perfect" criterion is still missing. Despite several pitfalls, which can be recognized intraoperatively and do not necessarily lead to a more extensive surgery, IOPTH seems to be a useful adjunct in surgery for PHPT. However, according to current guidelines, selected patients may be operated without IOPTH but need to be informed about the possibly increased risk of recurrent disease.

Focused Parathyroidectomy Using Accurate Preoperative Imaging and Intraoperative PTH: Tertiary Care Experience

INTRODUCTION

The cure rate after focused parathyroidectomy (FP) is dependent upon two critical adjuncts- concordant preoperative imaging and intraoperative parathyroid hormone (PTH), a technique which can reliably determine whether any other hyperfunctioning gland or glands are still present after resection of the lesion shown by imaging. We wanted to see the cure rate of FP by using these two adjuncts. We also sought to discern whether utilizing the central lab rapid PTH assay will lead to wider acceptance of this FP with intraoperative PTH in resource-constrained countries. This analysis was also undertaken to find out cost-effective way of doing intraoperative PTH by minimizing the samples for intraoperative PTH study.

RESULT

Data were collected on 83 patients with sporadic primary hyperparathyroidism (PHPT) who underwent parathyroidectomy in two tertiary centers between '2009 and 2017'. A total of 75 patients had concordant imaging, while seven had discordant imaging. The sensitivity and specificity of intraoperative PTH in FP was 100%. All the 78 patients who had fall in intraoperative PTH (50%) at 10 min also had fall of more than 50% at 5 min except one patient (98.7%).

CONCLUSION

We strongly advocate routine use of intraoperative PTH in all patients undergoing minimally invasive parathyroidectomy, as this adjunct offers maximum safety for the patient and confidence for the surgeon. Cost can be minimized by utilizing the central laboratory and reducing the number of samples.

Intraoperative parathyroid hormone levels ≤40 pg/mL are associated with the lowest persistence rates after parathyroidectomy for primary hyperparathyroidism

BACKGROUND

Intraoperative parathyroid hormone (IOPTH) monitoring is used to predict biochemical cure during parathyroidectomy for primary hyperparathyroidism; however, there is variability in the intraoperative parathyroid hormone criteria used by surgeons to predict normocalcemia after parathyroidectomy. This study sought to determine the intraoperative parathyroid hormone criteria correlated with the lowest rates of persistent hyperparathyroidism after parathyroidectomy for primary hyperparathyroidism.

MATERIALS AND METHODS

This is a retrospective cohort study of 2,654 patients with primary hyperparathyroidism who underwent parathyroidectomy with intraoperative parathyroid hormone monitoring at a single institution from 1999 to 2014. Multivariate logistic regression analysis was used to measure the association between the lowest intraoperative parathyroid hormone level and the persistence of primary hyperparathyroidism after parathyroidectomy.

RESULTS

A total of 66 patients (2.5%) had persistent hyperparathyroidism after parathyroidectomy. Using the traditional intraoperative parathyroid hormone criteria of a ≥50% decrease from the baseline level, the rate of persistent primary hyperparathyroidism was greater when intraoperative parathyroid hormone did not decrease to ≥50% from the baseline level (17 of 180 patients [9.4%] vs 49 of 2,474 [2.0%], [OR 5.9, 95% CI 3.2-10.5, P < .001]). Regardless of whether intraoperative parathyroid hormone decreased ≥50%, patients with a lowest intraoperative parathyroid hormone above the normal range (10-65 pg/mL) had greater persistence rates compared with patients with an intraoperative parathyroid hormone <65 pg/mL (30 of 350 [8.6%] vs 36 of 2,304 [1.6%], [OR 6.6, 95% CI 3.4-12.7, P < .001]). Furthermore, patients with a lowest intraoperative parathyroid hormone 40 to 65 pg/mL had increased rates of adjusted persistence compared with patients with lowest intraoperative parathyroid hormone ≤40 pg/mL (13 of 385 [3.4%] vs 23 of 1,919 [1.2%], [OR 4.2, 95% CI 2.0-8.7, P < .001]). Patients with lowest intraoperative parathyroid hormone <5 to 20 pg/mL did not have decreased rates of persistence compared with patients with lowest intraoperative parathyroid hormone 20 to 40 pg/mL (9 of 996 [0.9%] vs 14 of 923 [1.5%], [OR 0.5, 95% CI 0.2-1.2, P = .14]).

CONCLUSION

Patients with a lowest intraoperative parathyroid hormone ≤40 pg/mL compared with the traditional criteria of a ≥50% decrease from baseline and a final parathyroid hormone in the normal range (<65 pg/mL) had the lowest rates of persistent primary hyperparathyroidism after parathyroidectomy for primary hyperparathyroidism. The single criteria of a lowest intraoperative parathyroid hormone level ≤40 pg/mL may best predict the lowest persistent disease rates after parathyroidectomy for primary hyperparathyroidism.

Applicability of a shortened interpretation model for intraoperative parathyroid hormone monitoring in patients with primary hyperparathyroidism in an endemic goiter region

Background

In primary hyperparathyroidism (pHPT), quick intraoperative parathyroid hormone monitoring (IOPTH) is performed to predict complete excision of hyperfunctioning tissue and therefore cure. In recent years, efforts have been made to make this prediction more accurate and to shorten the duration of the test, respectively, and therefore reduce waiting and total operating time. The aim of this study was to evaluate the practicability and safety of a time-reduced criterion (decline ≥ 35% after 5 min) in a large cohort of patients.

Methods

In an 11-year period, all patients operated for pHPT were analyzed. After preoperative localization studies, hyperfunctioning parathyroid tissue was removed and IOPTH monitoring was performed. Intraoperatively, a decline of ≥50% from baseline 10 min after excision of the gland predicted cure. The performance of an interpretation model, using an earlier PTH level was analyzed retrospectively (decline ≥ 35% from baseline 5 min after excision). Differences in sensitivity, specificity, positive/negative predictive value and accuracy were calculated.

Results

According to the inclusion criteria, 1018 patients were analyzed. IOPTH predicted cure in 854 patients (83.9%) 10 min after gland excision with a false positive decline in 13 patients (1.5%). Applying the modified criterion (≥35% decline within 5 min), 814 patients (80%) showed an appropriate decline (false positive in 18 [2.2%]). Overall, multiple gland disease would have been missed in 7 patients. McNemar’s test showed a significantly lower sensitivity, specificity and accuracy applying the “35%” criterion.

Conclusions

In an endemic goiter region, a criterion, demanding a ≥ 35% decline 5 min after excision can not be recommended for IOPTH monitoring in patients with pHPT.

Niche point-of-care endocrine testing - Reviews of intraoperative parathyroid hormone and cortisol monitoring

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.

Primary hyperparathyroidism: Dynamic postoperative metabolic changes

OBJECTIVE

Little is known about the natural changes in parathyroid function after successful parathyroid surgery for primary hyperparathyroidism. The association of intact parathyroid hormone (iPTH) and calcium (Ca) with "temporary hypoparathyroidism" and "hungry bone syndrome" (HBS) was evaluated.

DESIGN

Potential risk factors for temporary hypoparathyroidism and HBS were evaluated by taking blood samples before surgery, intra-operatively, at postoperative day (POD) 1, at POD 5 to 7, in postoperative week (POW) 8 and in postoperative month (POM) 6.

PATIENTS

Of 425 patients, 43 (10.1%) had temporary hypoparathyroidism and 36 (8.5%) had HBS.

MEASUREMENTS

The discriminative ability of iPTH and Ca on POD 1 for temporary hypoparathyroidism and HBS.

RESULTS

Intact parathyroid hormone (IPTH) on POD 1 showed the highest discriminative ability for temporary hypoparathyroidism (C-index = 0.952), but not for HBS. IPTH was helpful in diagnosing HBS between POD 5 and 7 (C-index = 0.708). Extending the model by including Ca resulted in little improvement of the discriminative ability for temporary hypoparathyroidism (C-index = 0.964) and a decreased discriminative ability for HBS (C-index = 0.705). Normal parathyroid metabolism was documented in 139 (32.7%) patients on POD 1 and in 423 (99.5%) 6 months postoperatively, while 2 (0.5%) patients had persistent hyperparathyroidism, one diagnosed between POD 5 and 7 and another at POW 8. No patients suffered from permanent hypoparathyroidism.

CONCLUSIONS

The necessity for Ca and vitamin D3 substitution cannot be predicted with certainty before POD 5 to 7 without serial laboratory measurements. Based on the results, a routine 8-week course of Ca and vitamin D3 treatment seems reasonable and its necessity should be evaluated in a follow-up study.

The impact of vitamin D status on hungry bone syndrome after surgery for primary hyperparathyroidism

OBJECTIVE

Prolonged hypocalcemia but normal intact parathyroid hormone (iPTH) levels after surgery for primary hyperparathyroidism (PHPT) are referred to as 'hungry bone syndrome' (HBS). The aim was to evaluate preoperative risk factors for HBS with a focus on the impact of 25-hydroxyvitamin D (25(OH)D) deficiency.

DESIGN

Patients having undergone initial successful surgery for sporadic PHPT within 6 years were considered for retrospective analysis.

METHODS

A total of 385 patients were evaluated, of whom 33 (8.6%) developed HBS influencing negatively the postoperative bone metabolism. All patients underwent biochemical evaluations two days before parathyroid surgery and were followed biochemically on a daily basis in the first postoperative week and thereafter at 8 weeks and 6 months.

CONCLUSIONS

No relationship was established between preoperative 25(OH)D deficiency and HBS. The only significant risk factor for HBS in multivariable analysis was high levels of preoperative iPTH. As HBS therefore cannot be predicted preoperatively, we recommend a consistent postoperative calcium and vitamin D supplementation to improve the bone metabolism.

Contemporary surgical treatment of primary hyperparathyroidism without intraoperative parathyroid hormone measurement

INTRODUCTION

Primary hyperparathyroidism (pHPT) is usually the result of a single adenoma that can often be accurately located preoperatively and excised by a focused operation. Intraoperative parathyroid hormone (IOPTH) measurement is used occasionally to detect additional abnormal glands. However, it remains controversial as to whether IOPTH monitoring is necessary. This study presents the results of a large series of focused parathyroidectomy without IOPTH measurement.

METHODS

Data from 2003 to 2014 were collected on 180 consecutive patients who underwent surgical treatment for pHPT by a single surgeon. Preoperative ultrasonography and sestamibi imaging was performed routinely, with computed tomography (CT) and/or selective venous sampling in selected cases. The preferred procedure for single gland disease was a focused lateral approach guided by on-table surgeon performed ultrasonography. Frozen section was used selectively and surgical cure was defined as normocalcaemia at the six-month follow-up appointment.

RESULTS

Focused surgery was undertaken in 146 patients (81%) and 97% of these cases had concordant results with two imaging modalities. In all cases, an abnormal gland was discovered at the predetermined site. Of the 146 patients, 132 underwent a focused lateral approach (11 of which were converted to a collar incision), 10 required a collar incision and 4 underwent a mini-sternotomy. At 6 months following surgery, 142 patients were normocalcaemic (97% primary cure rate). Three of the four treatment failures had subsequent surgery and are now biochemically cured. There were no complications or cases of persistent hypocalcaemia.

CONCLUSIONS

This study provides further evidence that in the presence of concordant preoperative imaging, IOPTH measurement can be safely omitted when performing focused parathyroidectomy for most cases of pHPT.

[Avoidance and management of hypoparathyroidism after thyroid gland surgery]

Postoperative hypoparathyroidism after bilateral thyroid gland surgery or after interventions for recurrence is defined as intact parathyroid hormone levels (iPTH) < 15 pg/ml with simultaneous normal, below normal and markedly decreased serum calcium levels. After bilateral thyroid surgery and after reoperations a single iPTH measurement performed 12-24 h postoperatively can be used to predict parathyroid metabolism. Patients with an iPTH level ≥ 15 pg/ml may be discharged safely, patients with an iPTH < 10 pg/ml must be substituted with calcium and vitamin D and patients with an iPTH between 10 and 15 pg/ml (grey zone) may be discharged if a second measurement 48 h after surgery documents an iPTH ≥ 15 pg/ml. This procedure increases the length of hospital stay. Patients in the (grey zone) must be substituted. The iPTH level and its course determine the necessity, dose and length of calcium and vitamin D substitution.

Compliance with recommendations on surgery for primary hyperparathyroidism-from guidelines to real practice: results from an Iberian survey

PURPOSE

Knowledge about compliance with recommendations derived from the positional statement of the European Society of Endocrine Surgeons on modern techniques in primary hyperparathyroidism surgery and the Third International Workshop on management of asymptomatic primary hyperparathyroidism is scarce. Our purpose was to check it on a bi-national basis and determine whether management differences may have impact on surgical outcomes.

METHODS

An online survey including questions about indications, preoperative workup, surgical approach, intraoperative adjuncts, and outcomes was sent to institutions affiliated to the endocrine surgery divisions of the National Surgical Societies from Spain and Portugal. A descriptive evaluation of the responses was performed. Finally, we assessed the correlation between the different types of management with the achievement of optimal results, defined as a cure rate equal or greater than the median of all interviewed institutions.

RESULTS

Fifty-seven hospitals (41 Spanish, 16 Portuguese) answered the survey. First-ordered imaging tests were neck ultrasound and sestamibi scan. Facing negative or non-concordant results, 44 % of surgeons ordered additional tests before first-time surgery, and 84 % before reoperations. When indicated, selective parathyroidectomy was an acceptable option for 95 % of institutions as first-time surgery and for 51 % in reoperations. Intraoperative parathormone measurements were used by 92 % of departments. The surgical outcomes were good in most institutions (median cure rate 97 %) and were influenced mostly by the presence of an endocrine surgery unit in the surgical department (p = 0.038).

CONCLUSIONS

Practice of Iberian endocrine surgeons is consistent with current recommendations on surgery for primary hyperparathyroidism, with variability in some areas.

Sporadic multiple parathyroid gland disease--a consensus report of the European Society of Endocrine Surgeons (ESES)

BACKGROUND

Sporadic multiglandular disease (MGD) has been reported in literature in 8-33 % of patients with primary hyperparathyroidism (pHPT). This paper aimed to review controversies in the pathogenesis and management of sporadic MGD.

METHODS

A literature search and review was made to evaluate the level of evidence concerning diagnosis and management of sporadic MGD according to criteria proposed by Sackett, with recommendation grading by Heinrich et al. and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. Results were discussed at the 6th Workshop of the European Society of Endocrine Surgeons entitled 'Hyperparathyroidism due to multiple gland disease: An evidence-based perspective'.

RESULTS

Literature reports no prospective randomised studies; thus, a relatively low level of evidence was achieved. Appropriate surgical therapy of sporadic MGD should consist of a bilateral approach in most patients. Unilateral neck exploration guided by preoperative imaging should be reserved for selected patients, performed by an experienced endocrine surgeon and monitored by intraoperative parathormone assay (levels of evidence III-V, grade C recommendation). There is conflicting or equally weighted levels IV-V evidence supporting that cure rates can be similar or worse for sporadic MGD than for single adenomas (no recommendation). Best outcomes can be expected if surgery is performed by an experienced parathyroid surgeon working in a high-volume centre (grade C recommendation). Levels IV-V evidence supports that recurrent/persistence pHPT occurs more frequently in patients with double adenomas hence in situations where a double adenoma has been identified, the surgeon should have a high index of suspicion during surgery and postoperatively for the possibility of a four-gland disease (grade C recommendation).

CONCLUSIONS

Identifying preoperatively patients at risk for MGD remains challenging, intraoperative decisions are important for achieving acceptable cure rates and long-term follow-up is mandatory in such patients.

Intraoperative Parathyroid Hormone Monitoring: Optimal Utilization

Intraoperative parathyroid hormone (IOPTH) monitoring is a highly accurate surgical adjunct used to determine the extent of surgery in the setting of primary hyperparathyroidism. It is the successful interpretation of changes in PTH levels that is essential for using this technique in a way to optimize cure. Thus, it is imperative that the surgeon has an understanding of PTH dynamics and carefully chooses the appropriate IOPTH protocol and interpretation criteria that will best predict operative success, minimize unnecessary bilateral exploration, decrease the likelihood of resecting parathyroid glands that are not hypersecreting, and prevent recurrence.

A Retrospective Study of the Impact of Intraoperative Intact Parathyroid Hormone Monitoring During Total Parathyroidectomy for Secondary Hyperparathyroidism: STARD Study

The study aimed to evaluate the diagnostic accuracy of intraoperative intact parathyroid hormone (IO-iPTH) in patients with secondary hyperparathyroidism (HPT). The cut-off for IO-iPTH monitoring remains unknown. This was a single-center retrospective review of 226 consecutive patients (107 males and 119 females) who underwent parathyroidectomy for secondary HPT between May 2010 and March 2014. The predetermined cut-off for IO-iPTH was a 70% IO-iPTH drop from baseline 10 minutes after total parathyroidectomy and thymectomy. We used <60 pg/mL iPTH value on postoperative day 1 (POD1) as an indicator of successful removal of parathyroid glands and reviewed the frequency of reoperation other than in autografted sites during the observation period. This study was based on the Standards for the Reporting of Diagnostic accuracy compliant. The reoperation rate in patients with >60 pg/mL iPTH value (POD1) was significantly higher than that in patients with <60 pg/mL iPTH value (POD1), (13.0% versus 0.5% P = 0.003). Sensitivity, specificity, and accuracy of >70% IO-iPTH drop were 97.5%, 52.2%, and 92.9%, respectively, this criterion was demonstrated to be beneficial in 26 patients. In 5 patients, <70% IO-iPTH drop was observed and further exploration enabled sufficient removal of parathyroid glands. In 21 patients, although fewer than 4 parathyroid glands were removed after enough explorations, >70% IO-iPTH drop enabled termination of operations and iPTH value (POD1) was <60 pg/mL.An iPTH value of <60 pg/mL (POD1) was a good predictor for successful parathyroidectomy. A 70% IO-iPTH drop from the baseline was appropriate to determine sufficient parathyroid gland removal during parathyroidectomy for patients with secondary HPT. [Corrected]

The current status of intraoperative iPTH assay in surgery for primary hyperparathyroidism

Intraoperative intact parathyroid hormone (iPTH) monitoring has been accepted by many centers specializing in parathyroid surgery as a useful adjunct during surgery for primary hyperparathyroidism. This method can be utilized in three discreet modes of application: (I) to guide surgical decisions during parathyroidectomy in one of the following clinical contexts: (i) to confirm complete removal of all hyperfunctioning parathyroid tissue, which allows for termination of surgery with confidence that the hyperparathyroid state has been successfully corrected; (ii) to identify patients with additional hyperfunctioning parathyroid tissue following the incomplete removal of diseased parathyroid/s, which necessitates extended neck exploration in order to minimize the risk of operative failure; (II) to differentiate parathyroid from non-parathyroid tissue by iPTH measurement in the fine-needle aspiration washout; (III) to lateralize the side of the neck harboring hyperfunctioning parathyroid tissue by determination of jugular venous gradient in patients with negative or discordant preoperative imaging studies, in order to increase the number of patients eligible for unilateral neck exploration. There are many advantages of minimally invasive parathyroidectomy guided by intraoperative iPTH monitoring, including focused dissection in order to remove the image-indexed parathyroid adenoma with a similar or even higher operative success rate, lower prevalence of complications and shorter operative time when compared to conventional bilateral neck exploration. However, to achieve such excellent results, the surgeon needs to be aware of hormone dynamics during parathyroidectomy and carefully choose the protocol and interpretation criteria that best fit the individual practice. Understanding the nuances of intraoperative iPTH monitoring allows the surgeon for achieving intraoperative confidence in predicting operative success and preventing failure in cases of unsuspected multiglandular disease, while safely limiting neck exploration in the majority of patients with sporadic primary hyperparathyroidism. Thus, parathyroidectomy guided by intraoperative iPTH monitoring for the management of sporadic primary hyperparathyroidism is an ideal option for the treatment of this disease entity. However, the cost-benefit aspects of the standard application of this method still remain a matter of controversy.

Preoperative localization and intraoperative parathyroid hormone assay in korean patients with primary hyperparathyroidism

BACKGROUND

The intraoperative parathyroid hormone (IOPTH) assay is widely used in patients with primary hyperparathyroidism (PHPT). We investigated the usefulness of the IOPTH assay in Korean patients with PHPT.

METHODS

We retrospectively reviewed the data of 33 patients with PHPT who underwent parathyroidectomy. Neck ultrasonography (US) and 99mTc-sestamibi scintigraphy (MIBI scan) were performed preoperatively and IOPTH assays were conducted.

RESULTS

The sensitivity of neck US and MIBI scans were 91% and 94%, respectively. A 50% decrease in parathyroid hormone (PTH) levels 10 minutes after excision of the parathyroid gland was obtained in 91% (30/33) of patients and operative success was achieved in 97% (32/33) of patients. The IOPTH assay was 91% true-positive, 3% true-negative, 0% false-positive, and 6% false-negative. The overall accuracy of the IOPTH assay was 94%. In five cases with discordant neck US and MIBI scan results, a sufficient decrease in IOPTH levels helped the surgeon confirm the complete excision of the parathyroid gland with no additional neck exploration.

CONCLUSION

The IOPTH assay is an accurate tool for localizing hyperfunctioning parathyroid glands and is helpful for evaluating cases with discordant neck US and MIBI scan results.

Outcomes of Total Parathyroidectomy with Autotransplantation versus Subtotal Parathyroidectomy with Routine Addition of Thymectomy to both Groups: Single Center Experience of Secondary Hyperparathyroidism

BACKGROUND

Secondary hyperparathyroidism is a common acquired disorder seen in chronic renal failure. It may result in potentially serious complications including metabolic bone diseases, severe atherosclerosis and undesirable cardiovascular events. Parathyroidectomy is required in about 20% of patients after 3-10 years of dialysis and in up to 40% after 20 years.

AIMS

The aim of the current study was to evaluate the short-term and long-term outcomes of patients with secondary hyperparathyroidism who had undergone total parathyroidectomy with autotransplantation and thymectomy or subtotal parathyroidectomy with thymectomy by the same surgical team during the study period.

STUDY DESIGN

Retrospective comparative study.

METHODS

Clinical data of 50 patients who underwent parathyroid surgery for secondary hyperparathyroidism between 2003 and 2011 were reviewed retrospectively. Patients were divided into two subgroups of total parathyroidectomy with autotransplantation or subtotal parathyroidectomy. Thymectomy was routinely performed for both groups. Short term outcome parameters included intact parathyroid hormone, ionized calcium and alkaline phosphatase levels. Bone pain, bone fractures, persistent or recurrent disease were included in long term outcome parameters.

RESULTS

The mean duration of dialysis was eight years. The mean ionized calcium levels dropped significantly in the total parathyroidectomy with autotransplantation group (p=0.016). No serious postoperative complications were observed. Postoperative intravenous calcium supplementation was required in four patients in the total parathyroidectomy with autotransplantation group (total PTX+AT) and in three patients in the subtotal parathyroidectomy group (subtotal PTX). Postoperatively, all patients received oral calcium carbonate and calcitriol. The length of average hospital stay was 5 (3-10) days. Including nine patients who underwent successful renal transplantation pre-operative bone symptoms, hypercalcemia, hyperphosphatemia, and an increased alkaline phosphatase levels were improved or resolved in all patients. After a mean follow-up of 65 months, three patients (6%) had persistent and one (2%) had recurrent disease.

CONCLUSION

Total parathroidectomy with autotransplantation is a beneficial and safe surgical procedure for patients on chronic dialysis with otherwise uncontrollable secondary hyperparathroidism and even in patients who have undergone renal transplantation after parathyroidectomy. Careful cervical exploration and routine thymectomy should be considered as a routine part of the surgical approach regardless of the preferred technique.

Intraoperative PTH monitoring: a new approach based on the identification of the "true" time origin of the decay curve

Some published criteria for intraoperative monitoring of PTH serum concentrations may cause misleading results, since the timing of samples measured between the pre-incision and pre-excision phase of surgery is often unrecorded. In our opinion this information is critical, as the time of an intermediate sample during surgical manipulation may represent the "true" beginning of the PTH decay. We modified the usual criterion of monitoring (cut-off at 10 minutes after clamping) proposing a further check at manipulation in case the primary check at clamping produces an apparently negative result. On the basis of a mathematical model, false negative curves were simulated by means of a time shift. This shift was assumed to be the interval between manipulation and clamping. Analysing the decay curve, we used the 50% cut-off at 10 minutes after the supposed "true" origin (clamping or manipulation). Using a rapid immunochemiluminometric assay (ICMA), data were collected from 22 patients successfully operated for parathyroid adenoma. The check at clamping correctly diagnosed 13 patients. Among the 9 false negative cases, 6 were correctly diagnosed considering the manipulation as the baseline value. In the remaining 3 patients, diagnosis required prolonged observation of the curves. In case the iPTH decay does not follow the expected curve, it can be useful to check the decay normalising to a pre-excision value. The advantages of our criterion are both the prompt recognition of false negative results and the construction of a "true" decay curve for each patient, supporting the surgeon during the excision of hyperfunctioning parathyroid tissue.

Anesthetic techniques and parathyroid hormone levels: Predictor of surgical decisions

Endocrine surgeries have always been challenging and throw numerous challenges to the surgeons, anesthesiologists, and the endocrinologists. A thorough knowledge of the pathophysiological aspects associated with endocrinopathies is mandatory for the attending anesthesiologist. Parathyroid surgery is a very delicate procedure that requires immense and meticulous preparation during the perioperative period for achieving a clinical outcome. Parathyroid hormone (PTH) levels during intra-operative period can influence the decision making in surgery. Anesthetic techniques also play a significant role in the secretion of PTH during perioperative period, which can be decisive in re-assessment of surgical procedure on operation table. The present communication briefly outlines the various anesthetic techniques, which influence the secretion of PTH and also influence surgical decision making.

Intra-operative parathyroid hormone kinetics and influencing factors with high baseline PTH: a prospective study

BACKGROUND AND OBJECTIVE

Intra-operative parathyroid hormone (IOPTH) kinetics and therefore the efficacy of IOPTH utilization as a predictor of cure are likely to be affected by baseline IOPTH levels, vitamin D deficiency and parathyroid weight.

PATIENTS AND METHODS

Consecutive subjects with primary hyperparathyroidism (PHPT, n = 51) undergoing parathyroidectomy with IOPTH monitoring were studied prospectively during the period October 2009-November 2011. Samples were collected pre-incision, pre-excision and post-excision (5, 10, 15 min). Iterative analysis of IOPTH kinetics and half-life calculation was carried out in subgroups. Nonparametric testing was used for group statistics.

RESULTS

Hypovitaminosis D (25(OH)D3 < 50 nm) was present in 39 (76%), serum PTH > 1000 ng/l in 23 (45%), and giant parathyroid adenoma (weight > 3000 mg) in 23 (45%). The percentage drop at 10 min was significantly higher in large adenomas (weight > 3000 mg). Miami and 5 min criteria showed the highest negative predictive value and maximum accuracy. The average percentage IOPTH drop observed at 5 min post-excision was 79.8%. Kinetic analysis showed a mean half-life of PTH of 2.57 ± 0.27 min (range: 0.07-11.55).

CONCLUSION

IOPTH monitoring is reliable even in patients with extremely high baseline IOPTH value, with a greater percentage drop at 5 and 10 min post-excision. In patients with high baseline IOPTH, a 50% decay in PTH value at 5 min may be indicative of cure, obviating the need for 10 and 15 min samples. IOPTH kinetics are altered by adenoma weight but not affected by vitamin D status or baseline IOPTH levels.

Creation of a "Wisconsin index" nomogram to predict the likelihood of additional hyperfunctioning parathyroid glands during parathyroidectomy

OBJECTIVE

The aim of our study was to create a preoperative "index" that could predict the likelihood of additional hyperfunctioning parathyroid glands and let the surgeon determine whether to wait for the intraoperative parathyroid hormone (ioPTH) or to explore further.

BACKGROUND

During parathyroidectomy for primary hyperparathyroidism (PHPT), discovering a minimally "enlarged" parathyroid gland creates a dilemma for the surgeon regarding the need for further exploration. Although ioPTH testing can potentially solve this problem after a 20- to 30-minute period, several surgeons recognize that further operative exploration may be more effective.

METHODS

We analyzed a prospective database of 1235 consecutive patients who underwent parathyroidectomy for PHPT at our institution between March 2001 and August 2010. The Wisconsin Index (WIN) was defined as the multiplication of preoperative serum calcium by preoperative parathyroid hormone (PTH). Patients were divided into 3 WIN categories: low (<800), medium (801-1600), and high (>1600). The utility of the WIN was then validated on a subsequent cohort of 216 patients.

RESULTS

The median age of the patients was 61 years (range, 10-91), and 77% of the patients were female. The mean preoperative calcium and PTH levels were 11.0 ± 0 mg/dL and 127 ± 3 pg/mL, respectively. The mean WIN for the entire cohort was 1461 ± 38 and highly correlated with gland weight (P < 0.000001). A single adenoma was identified in 1000 patients (81%), double adenoma in 100 patients (8%), and hyperplasia in 135 patients (11%). The mean gland weights for the 3 WIN catagories were low = 370 ± 33 mg, medium = 532 ± 39 mg, and high = 985 ± 28 mg, respectively (P < 0.000001). A WIN nomogram, consisting of the combination of WIN and parathyroid gland weight, accurately predicted the likelihood of additional hyperfunctioning parathyroid glands. For example, for a WIN of less than 800 and a gland weight of 500 mg, there is a 9% chance for additional hyperfunctioning parathyroid glands based on the WIN nomogram. In contrast, for the same gland weight, if the WIN is 801 to 1600, these chances increase to 28%, and if the WIN is more than 1600, the chance of multigland disease is 61%. Comparison between the predicted chances for another gland with the actual chance in the validation cohort identified an R(2) value of 0.96.

CONCLUSIONS

The WIN nomogram predicts the likelihood of additional hyperfunctioning parathyroid glands during parathyroidectomy. This simple intraoperative tool may be used to guide the decision of whether to wait for ioPTH results or to proceed with further neck exploration.

Current trends in surgery for renal hyperparathyroidism (RHPT)--an international survey

PURPOSE

The indications and results of preoperative localization, surgical strategy, indication for thymectomy, the application of intraoperative parathyroid hormone (PTH) monitoring, cryopreservation, and replantation of cryopreserved parathyroid tissue are not well documented in renal hyperparathyroidism (RHPT). The current trends in surgery for RHPT are to be evaluated in an international online survey.

METHODS

Thirty-three questions regarding preoperative localization, surgical management of RHPT, intraoperative PTH monitoring, immediate/delayed autotransplantation (AT), and parathyroid cryopreservation were sent to members of various societies of endocrine surgeons.

RESULTS

The data from 86 responses were analyzed, 61.6 % reported more than 50 parathyroid surgeries per year, and 62.7 % operated on less than 16 patients with RHPT per year. Subtotal or total parathyroidectomy (with/without AT) was the standard procedure in 98.8 % of the cases. Immediate AT was performed in 40.7 % (72.7 % in the forearm). In most patients, the onset of graft function was documented later than 1 week after AT. Cryopreservation was routinely performed in 27.4 %. In 10.7 %, replantation was performed in more than five patients (hypo- or aparathyroidism: n = 41; fresh graft failure: n = 13; reoperations: n = 9). Intraoperative PTH monitoring (in RHPT) was routinely used in 46.2 %. Its influence on surgical strategy was confirmed in 40 %.

CONCLUSIONS

The survey reflects the divergent strategies applied for AT, cryopreservation, and PTH monitoring in RHPT.

Transient increases in intraoperative parathyroid levels related to anesthetic technique

BACKGROUND

Parathyroid hormone (PTH) secretion is partially regulated by circulating catecholamines. We examined the effect of different anesthetic techniques on intraoperative PTH (IOPTH) levels in patients undergoing parathyroidectomy for primary hyperparathyroidism.

METHODS

We prospectively studied 132 patients divided into 3 anesthetic cohorts: monitored anesthetic care (MAC; n = 45), general anesthesia with laryngeal mask airway (LMA; n = 43), or general endotracheal anesthesia (GETA; n = 39). IOPTH levels were drawn before induction and at defined intervals postinduction.

RESULTS

All anesthetic techniques increased IOPTH levels from preinduction to 3 minutes postinduction (MAC, 28%; LMA, 45%; GETA, 65%; P < .001). Temporal trends in postinduction IOPTH levels were similar in patients receiving general anesthesia, characterized by a peak effect at 6 minutes. Using a multivariate logistic regression analysis, GETA was >7 times more likely to increase the preinduction IOPTH by ≥ 50% at 3 minutes postinduction compared with MAC (P < .0001). Using immediate postinduction IOPTH levels in surgical decision making would have led to failed surgery in 2 of 6 patients with multiple gland disease receiving GETA.

CONCLUSION

Preincision IOPTH samples should be drawn before induction to avoid incorporation of potentially misleading anesthetic-related IOPTH elevations into surgical decision making.

A 10-year experience in intraoperative parathyroid hormone measurements for primary hyperparathyroidism: a prospective study of 91 previous unexplored patients

Introduction. Primary hyperparathyroidism (PHP) is characteristically determined by high levels of calcium and high or inappropriate levels of parathyroid hormone (PTH). Technological advances have dramatically changed the surgical technique over the years once intraoperative parathyroid hormone (IOPTH) assay had allowed for focused approaches. Objective. To evaluate our 10-year experience in employing a rapid intraoperative PTH assay for PHP. Methods. A prospective cohort of 91 PHP-operated patients in a tertiary institution in São Paulo, Brazil, from June 2000 to April 2011. Results. We had 85 (93.4%) successful parathyroidectomies, 6 (6.6%) failed parathyroidectomies in 91 previous unexplored patients, and 5 (100%) successful remedial surgeries. The IOPTH was true-positive in 88.5%, true-negative in 7.3%, false-positive in 2.1%, and false-negative in 2.1% of the procedures. IOPTH was able to obviate additional exploration or to ask for additional exploration in 92 (95.8%) procedures. Conclusion. The IOPTH revealed to be an important technological adjunct in the current parathyroid surgery for PHP.

Contemporary and practical uses of intraoperative parathyroid hormone monitoring

OBJECTIVE

To describe the evolution and current applications of intraoperative parathyroid hormone (PTH) monitoring along with a detailed description of intraoperative protocol and assay methodology.

METHODS

Review of the literature regarding the role of intraoperative PTH monitoring in parathyroidectomy, controversies associated with its use in the treatment of hyperparathyroidism, and outcomes using this operative approach. The technologies currently available for "quick" PTH measurement are summarized.

RESULTS

Since its inception, intraoperative PTH monitoring has become an essential tool in the endocrine surgeon's armamentarium for treatment of sporadic primary hyperparathyroidism. Intraoperative PTH monitoring changed the operative approach to this disease from bilateral neck exploration with identification of all parathyroid glands and excision based on size, to a highly successful procedure achieved with a limited dissection and gland excision guided by hormone hypersecretion instead of morphologic characteristics. Intraoperative PTH monitoring accuracy is directly associated with the intraoperative criteria used. Although controversy exists regarding the best intraoperative PTH monitoring criteria to be used, most specialized centers have shown excellent results with this intraoperative guidance. Currently, most parathyroid surgeons use intraoperative PTH monitoring, selectively or routinely, during parathyroidectomy.

CONCLUSION

Parathyroidectomy guided by intraoperative PTH monitoring to treat sporadic primary hyperparathyroidism is a highly successful and less-invasive approach associated with lower risks than bilateral neck exploration, and it has become the surgical treatment of choice for this disease.

[Relationship between parathormone concentration during surgery and the post-operative outcome of primary hyperparathyroidism]

INTRODUCTION

The relationship between the intra-operative concentration of parathyroid hormone (IOPTH) and the long-term outcome of patients intervened due to primary hyperparathyroidism (PHPT).

PATIENTS AND METHODS

A prospective observational study was performed with 120 patients. Three determinations were made of PTH in blood: baseline, when the diseases gland was located, and 10 minutes after its extirpation. The calcium, PTH and vitamin D (25-OH-D3) levels were measured during follow up.

RESULTS

A decrease in IOPTH > 50% was observed in 96 (80%) patients, and the post-extirpation value returned to the normal range (Group I), in 18 (15%) a decrease of > 50% but the final value remained higher than normal (Group II) and in 6 (5%) the decrease was<50% (Group III). Persistent PHPT was detected during follow up in 6 patients (5%): one in Group I (1%), 3 (16.7%) in II and 2 (33.3%) in group III (P<.001). The risk of persistent PHPT was higher in Group II (odds ratio: 19; 95% CI: 1.85-194) and in Group III (odds ratio: 47; 95% CI: 3.53-639). There were no cases of recurrent PHPT. A normal calcium with an increased PTH was detected in 20 patients of Group I (20.8%), 11 (61.1%) in II and 3 (50%) in III (P<.001). These patients had a lower concentration of post-operative vitamin D (17 ng/ml, range: 24; compared to 28 ng/ml, range: 21) (P=.008) and higher frequency of hypovitaminosis D (70.6% compared to 26.2%) (P>.001).

CONCLUSION

The risk of persistent PHPT is higher when the IOPTH decreases more than 50% but still remains high.

Intraoperative adjuncts for parathyroid surgery

In recent years, parathyroid surgery has evolved from traditional bilateral neck exploration to minimal invasive parathyroidectomy. This trend became possible due to preoperative localization imaging that guides the surgeon in the search for a parathyroid adenoma. Intraoperative adjuncts are complementary to preoperative localization and assist in localizing parathyroid glands, confirming parathyroid tissue and establishing a cure. Institutions and surgeons utilize different intraoperative adjuncts in different protocols with varying results. The purpose of this article is to review the available intraoperative adjuncts to parathyroid surgery and critically evaluate their utility, accuracy and their added value to the surgeon.