Cure Predictability During Parathyroidectomy

Does the Use of Probe-based Near-infrared Autofluorescence Parathyroid Detection Benefit Parathyroidectomy?: A Randomized Single-center Clinical Trial

OBJECTIVE

To evaluate the benefits of probe-based near-infrared autofluorescence (NIRAF) parathyroid identification during parathyroidectomy.

BACKGROUND

Intraoperative parathyroid gland identification during parathyroidectomy can be challenging, while additionally requiring costly frozen sections. Earlier studies have established NIRAF detection as a reliable intraoperative adjunct for parathyroid identification.

METHODS

Patients undergoing parathyroidectomy for primary hyperparathyroidism were prospectively enrolled by a senior surgeon (>20 years experience) and a junior surgeon (<5 years experience), while being randomly allocated to the probe-based NIRAF or control group. Data collected included procedure type, number of parathyroids identified with high confidence by the surgeon and the resident, number of frozen sections performed, parathyroidectomy duration, and number of patients with persistent disease at the first postoperative visit.

RESULTS

One hundred sixty patients were randomly enrolled under both surgeons to the probe group (n=80) versus control (n=80). In the probe group, parathyroid identification rate of the senior surgeon improved significantly from 3.2 to 3.6 parathyroids per patient ( P <0.001), while that of the junior surgeon also rose significantly from 2.2 to 2.5 parathyroids per patient ( P =0.001). Parathyroid identification was even more prominent for residents increasing significantly from 0.9 to 2.9 parathyroids per patient ( P <0.001). Furthermore, there was a significant reduction in frozen sections utilized in the probe group versus control (17 vs 47, P =0.005).

CONCLUSION

Probe-based NIRAF detection can be a valuable intraoperative adjunct and educational tool for improving confidence in parathyroid gland identification, while potentially reducing the number of frozen sections required.

New Techniques for Intraoperative Parathyroid Localization

Accurate identification of abnormal parathyroid glands (PGs) during parathyroidectomy and thyroidectomy can be challenging even for experienced surgeons given PGs variable location, size, and similar appearance to surrounding tissue. Inadvertent removal or devascularization of healthy PGs can lead to transient or permanent hypoparathyroidism. Permanent hypoparathyroidism is associated with increased rates of renal insufficiency, seizures, skeletal abnormalities, increased costs, decreased quality of life, and increased mortality. Conversely, the inability to identify and remove hyperfunctioning PGs results in failed parathyroidectomy which can result in need for reoperations that are associated with increased technical difficulty, operative duration, rates of hypoparathyroidism and recurrent laryngeal nerve damage, and cost.

Primary Adenoma Arising From Two Ipsilateral Supernumerary Inferior Parathyroid Adenomas

A single parathyroid adenoma is the most common cause of primary hyperparathyroidism (PHPT). However, multiple synchronous adenomas can be found at surgery. More uncommon are ipsilateral synchronous adenomas, and that combined with a supernumerary gland, is even more rare. Here we present a case of PHPT due to an ipsilateral double adenoma of the inferior parathyroid gland, which was supernumerary. The diagnosis was made preoperatively by ultrasonography; however, sestamibi scan showed only a single hyperfunctioning gland on the left side. This was further substantiated by the use of intraoperative parathyroid hormone (PTH) monitoring, wherein PTH levels decreased to less than 50% of preoperative values only after the complete removal of the second adenomatous gland. This case report highlights the importance of preoperative localization and intraoperative PTH monitoring in evaluating patients with PHPT in the setting of multiple synchronous parathyroid adenoma.

Educational Review: Intraoperative Parathyroid Fluorescence Detection Technology in Thyroid and Parathyroid Surgery

BACKGROUND

Accurate parathyroid gland (PG) identification is a critical yet challenging component of cervical endocrine procedures. PGs possess strong near-infrared autofluorescence (NIRAF) compared with other tissues in the neck. This property has been harnessed by image- and probe-based near-infrared fluorescence detection systems, which have gained increasing popularity in clinical use for their ability to accurately aid in PG identification in a rapid, noninvasive, and cost-effective manner. All NIRAF technologies, however, cannot differentiate viable from devascularized PGs without the use of contrast enhancement. Here, we aim to provide an overview of the rapid evolution of these technologies and update the surgery community on the most recent advancements in the field.

METHODS

A PubMed literature review was performed using the key terms "parathyroid," "near-infrared," and "fluorescence." Recommendations regarding the use of these technologies in clinical practice were developed on the basis of the reviewed literature and in conjunction with expert surgeons' opinions.

RESULTS

The use of near-infrared fluorescence detection can be broadly categorized as (1) using parathyroid NIRAF to identify both healthy and diseased PGs, and (2) using contrast-enhanced (i.e., indocyanine green) near-infrared fluorescence to evaluate PG perfusion and viability. Each of these approaches possess unique advantages and disadvantages, and clinical trials are ongoing to better define their utility.

CONCLUSIONS

Near-infrared fluorescence detection offers the opportunity to improve our collective ability to identify and preserve PGs intraoperatively. While additional work is needed to propel this technology further, we hope this review will be valuable to the practicing surgeon.

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.

Predictors of adenoma size and location in primary hyperparathyroidism

Purpose

In primary hyperparathyroidism (PHPT), intraoperative localization of the parathyroid adenoma can be challenging, especially in cases of negative preoperative imaging. Since a focused unilateral parathyroidectomy has benefits compared to a conventional bilateral neck exploration, the question arises whether adenoma size prediction can facilitate a targeted approach. We investigated whether single parathyroid adenoma size can be estimated using preoperative parathyroid hormone (PTH), calcium, and phosphate in patients with PHPT. Preoperative imaging accuracy was evaluated.

Methods

The data of 156 patients who underwent curative parathyroidectomy for single adenoma PHPT were analyzed retrospectively. Information obtained included laboratory data, imaging results, intraoperative data, and final pathology. Imaging accuracy was analyzed descriptively. The association between preoperative biochemical markers and adenoma dimensions was investigated using Spearman’s correlation coefficient and multivariable regression modeling.

Results

Cervical ultrasound correctly predicted adenoma laterality in 95.5%, sestamibi scintigraphy in 80.6%, both had lower true-positive rates for quadrant prediction. Patients with negative imaging results showed higher thyroid volumes than those with positive results. Adenoma volume was positively correlated with preoperative PTH (p < 0.001) and calcium (p < 0.001) and negatively correlated with preoperative phosphate (p = 0.001). Using these preoperative biochemical markers and patient age and BMI, adenoma volume can be significantly predicted using the multivariable regression algorithm.

Conclusion

Cervical ultrasound is superior to scintigraphy for predicting adenoma location and should be the first-choice imaging method, but both methods may be limited by increased thyroid volume. Large adenomas are more likely with higher PTH, higher calcium, and lower phosphate levels. In cases of undetermined adenoma location, an estimation of adenoma volume via our algorithm could corroborate sonographic volume measurements of the suspected adenoma.

Minimally invasive parathyroidectomy guided by intraoperative parathyroid hormone monitoring (IOPTH) and preoperative imaging versus bilateral neck exploration for primary hyperparathyroidism in adults

BACKGROUND

Bilateral neck exploration (BNE) is the traditional approach to sporadic primary hyperparathyroidism. With the availability of the preoperative imaging techniques and intraoperative parathyroid hormone assays, minimally invasive parathyroidectomy (MIP) is fast becoming the favoured surgical approach.

OBJECTIVES

To assess the effects of minimally invasive parathyroidectomy (MIP) guided by preoperative imaging and intraoperative parathyroid hormone monitoring versus bilateral neck exploration (BNE) for the surgical management of primary hyperparathyroidism.

SEARCH METHODS

We searched CENTRAL, MEDLINE, WHO ICTRP and ClinicalTrials.gov. The date of the last search of all databases was 21 October 2019. There were no language restrictions applied.

SELECTION CRITERIA

We included randomised controlled trials comparing MIP to BNE for the treatment of sporadic primary hyperparathyroidism in persons undergoing surgery for the first time.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts for relevance. Two review authors independently screened for inclusion, extracted data and carried out risk of bias assessment. The content expert senior author resolved conflicts. We assessed studies for overall certainty of the evidence using the GRADE instrument. We conducted meta-analyses using a random-effects model and performed statistical analyses according to the guidelines in the latest version of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

We identified five eligible studies, all conducted in European university hospitals. They included 266 adults, 136 participants were randomised to MIP and 130 participants to BNE. Data were available for all participants post-surgery up to one year, with the exception of missing data for two participants in the MIP group and for one participant in the BNE group at one year. Nine participants in the MIP group and 11 participants in the BNE group had missing data at five years. No study had a low risk of bias in all risk of bias domains. The risk ratio (RR) for success rate (eucalcaemia) at six months in the MIP group compared to the BNE group was 0.98 (95% confidence interval (CI) 0.94 to 1.03; P = 0.43; 5 studies, 266 participants; very low-certainty evidence). A total of 132/136 (97.1%) participants in the MIP group compared with 129/130 (99.2%) participants in the BNE group were judged as operative success. At five years, the RR was 0.94 (95% CI 0.83 to 1.08; P = 0.38; 1 study, 77 participants; very low-certainty evidence). A total of 34/38 (89.5%) participants in the MIP group compared with 37/39 (94.9%) participants in the BNE group were judged as operative success. The RR for the total incidence of perioperative adverse events was 0.50, in favour of MIP (95% CI 0.33 to 0.76; P = 0.001; 5 studies, 236 participants; low-certainty evidence). Perioperative adverse events occurred in 23/136 (16.9%) participants in the MIP group compared with 44/130 (33.9%) participants in the BNE group. The 95% prediction interval ranged between 0.25 and 0.99. These adverse events included symptomatic hypocalcaemia, vocal cord palsy, bleeding, fever and infection. Fifteen of 104 (14.4%) participants experienced symptomatic hypocalcaemia in the MIP group compared with 26/98 (26.5%) participants in the BNE group. The RR for this event comparing MIP with BNE at two days was 0.54 (95% CI 0.32 to 0.92; P = 0.02; 4 studies, 202 participants). Statistical significance was lost in sensitivity analyses, with a 95% prediction interval ranging between 0.17 and 1.74. Five out of 133 (3.8%) participants in the MIP group experienced vocal cord paralysis compared with 2/128 (1.6%) participants in the BNE group. The RR for this event was 1.87 (95% CI 0.47 to 7.51; P = 0.38; 5 studies, 261 participants). The 95% prediction interval ranged between 0.20 and 17.87. The effect on all-cause mortality was not explicitly reported and could not be adequately assessed (very low-certainty evidence). There was no clear difference for health-related quality of life between the treatment groups in two studies, but studies did not report numerical data (very low-certainty evidence). There was a possible treatment benefit for MIP compared to BNE in terms of cosmetic satisfaction (very low-certainty evidence). The mean difference (MD) for duration of surgery comparing BNE with MIP was in favour of the MIP group (-18 minutes, 95% CI -31 to -6; P = 0.004; 3 studies, 171 participants; very low-certainty evidence). The 95% prediction interval ranged between -162 minutes and 126 minutes. The studies did not report length of hospital stay. Four studies reported intraoperative conversion rate from MIP to open procedure information. Out of 115 included participants, there were 24 incidences of conversion, amounting to a conversion rate of 20.8%.

AUTHORS' CONCLUSIONS

The success rates of MIP and BNE at six months were comparable. There were similar results at five years, but these were only based on one study. The incidence of perioperative symptomatic hypocalcaemia was lower in the MIP compared to the BNE group, whereas the incidence of vocal cord paralysis tended to be higher. Our systematic review did not provide clear evidence for the superiority of MIP over BNE. However, it was limited by low-certainty to very low-certainty evidence.

[Intraoperative measurement of parathyroid hormone in hyperparathyroidism]

Intraoperative parathyroid hormone (IOPTH) determination is based on the short half-life of parathyroid hormone (PTH) and the rapid analytical technology. The IOPTH provides functional information regarding correction of the overproductive state in hyperparathyroidism (HPT) and is superior to macroscopic evaluation of the parathyroid gland (PG) as well as any (intraoperative frozen section) form of histology (so-called biochemical frozen section). In this article the relevance and evaluation of IOPTH is defined for the most important forms of HPT, for primary HPT, renal secondary and tertiary HPT, multiple endocrine neoplasia type 1 (MEN1) and parathyroid carcinoma and clinical scenarios based on the currently available data. It becomes apparent that the additional benefits of IOPTH depend on diverse prerequisites of the specific type of HPT, the diagnostics as well as individual patient factors and strategic considerations for resection. Overall, the costs for IOPTH are comparably low and seem to be justified with respect to the gain in quality. In the hands of specialized endocrine surgeons IOPTH is an essential tool for intraoperative decision-making and quality assurance.

Current applications of artificial intelligence for intraoperative decision support in surgery

Research into medical artificial intelligence (AI) has made significant advances in recent years, including surgical applications. This scoping review investigated AI-based decision support systems targeted at the intraoperative phase of surgery and found a wide range of technological approaches applied across several surgical specialties. Within the twenty-one (n = 21) included papers, three main categories of motivations were identified for developing such technologies: (1) augmenting the information available to surgeons, (2) accelerating intraoperative pathology, and (3) recommending surgical steps. While many of the proposals hold promise for improving patient outcomes, important methodological shortcomings were observed in most of the reviewed papers that made it difficult to assess the clinical significance of the reported performance statistics. Despite limitations, the current state of this field suggests that a number of opportunities exist for future researchers and clinicians to work on AI for surgical decision support with exciting implications for improving surgical care.

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.

CALCIUM CREATININE CLEARANCE RATIO IS NOT HELPFUL IN DIFFERENTIATING PRIMARY HYPERPARATHYROIDISM FROM FAMILIAL HERPERCALCEMIC HYPOCALCIURIA: A STUDY OF 1000 PATIENTS

OBJECTIVE

With increasing recognition of more subtle presentations of primary hyperparathyroidism (pHPT), laboratory values are frequently seen in a range that would be expected for patients who have familial hypercalcemic hypocalciuria (FHH). Calcium creatinine clearance ratio (CCCR) has been advocated as a diagnostic tool to differentiate between these two disorders. However, it is limited by an indeterminate range (0.01-0.02). The aim of this study is to assess the relevance of CCCR in a modern series of patients with surgically managed pHPT.

METHODS

We performed a retrospective cohort study of 1000 patients who underwent parathyroid surgery for pHPT over eleven years. CCCR was evaluated by degree of biochemical derangement, single versus multiple gland disease and interfering medications.

RESULTS

Patient demographics and resected histopathology were typical for a current series of patients with pHPT. In retrospect, none of the patients were suspected to have FHH post operatively. CCCR was less than 0.01 for 19.0%, between 0.01-0.02 for 43.7% and greater than 0.02 in 37.3%. Distribution of CCCR for patients free from interfering medications and different histological subtypes were the same. One third of the cohort had mild calcium elevations, more typical for FHH. Of these, almost two thirds had a CCCR in a range suspect for FHH (<0.02).

CONCLUSION

To our knowledge this is the largest series to evaluate the validity of CCCR for patients with surgically confirmed pPHT. The utility of CCCR in screening for FHH is limited, as 63% of modern patients with confirmed pHPT have low values.

The surgical management of primary hyperparathyroidism: an updated review

Patients with primary hyperparathyroidism often present clinically asymptomatic with various biochemical compositions of serum calcium, parathyroid hormone, vitamin D and urinary calcium. Understanding the subtle differences in clinical and biochemical presentations is key for timely diagnosis and referral to an experienced parathyroid surgeon. Surgery remains the only option for cure of primary hyperparathyroidism, which now favors a directed parathyroidectomy with intra-operative adjuncts. However it is important to understand and revise the surgical approach for patients with hereditary conditions or nonlocalizing studies. Revised guidelines from the Fourth International Workshop on the Management of Asymptomatic Primary Hyperparathyroidism in 2013 and the American Association of Endocrine Surgeons in 2016 are reviewed in this paper for an updated review of this condition.

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.

Current predictive models do not accurately differentiate between single and multi gland disease in primary hyperparathyroidism: a retrospective cohort study of two endocrine surgery units

Background Minimally invasive parathyroidectomy (MIP) for primary hyperparathyroidism is dependent upon accurate prediction of single-gland disease on the basis of preoperative imaging and biochemistry. The aims of this study were to validate currently available predictive models of single-gland disease in two UK cohorts and to determine if these models can facilitate MIP. Methods This is a retrospectively cohort study of 624 patients who underwent parathyroidectomy for primary hyperparathyroidism in two centres between July 2008 and December 2013. Two recognised models: CaPTHUS (preoperative calcium, parathyroid hormone, ultrasound, sestamibi, concordance imaging) and Wisconsin Index (preoperative calcium, parathyroid hormone) were validated for their ability to predict single-gland disease. Results The rates of single- and multi-gland disease were 491 (79.6%) and 126 (20.2%), respectively. Cure rates in centres 1 and 2 were 93.2% and 93.8%, respectively (P = 0.789). The positive predictive value (PPV) of CaPTHUS score . 3 in predicting single-gland disease was 84.6%, compared with 100% in the original report. CaPTHUS . 4 and 5 had a PPV of 85.1 and 87.1, respectively. There were no differences in Wisconsin Index (WIN) between patients with single- and multi-gland (P = 0.573). A WIN greater than 1600 and weight of excised gland greater than 1 g had a positive predictive value of 86.7% for single-gland disease. Conclusions The use of CaPTHUS and WIN indices without intraoperative adjuncts (such as IOPTH) had the potential to result in failure to cure in up to 15% (CaPTHUS) and 13% (WIN) of patients treated by MIP targeting a single enlarged gland.

PRIMARY HYPERPARATHYROIDISM - STRATEGY FOR MULTIGLAND DISEASE IN THE ERA OF SPECT-CT

Purpose

To re-examine our clinical practice and review strategy for treatment of primary hyperparathyroidism in patients with multigland disease.

Methods

Retrospective analysis of 121 consecutive primary hyperparathyroidism (PHPT) patients who underwent surgery in a tertiary center between January 2010 and December 2014.

Results

Of 121 patients with PHPT 87% had single gland adenoma (SGD) and 13% had multigland disease (MGD). The overall cure rate was 95.86%. MGD was more frequent in younger persons (<40y)(50% vs. 13.2%). All patients had SPECT-CT (Single Proton Emission Computerized Tomography) with 28% being SPECT-CT negative. Patients with MGD had a higher rate of persistent disease (13.33% vs. 2.83%). Specimen weight was <600mg in 75% of MGD patients. 67% of SPECT-CT negative patients had mild hypercalcemia (Calcium <2.75 mmol/L) which was more frequent in MGD patients (43% vs. 19%).

Conclusions

MGD patients were more likely SPECT-CT negative (40% vs. 25.4%) and benefit from bilateral neck exploration (BNE) (74%). However, most SPECT-CT negative patients still have a single adenoma. In our series MGD was more frequent in younger patients, more likely SPECT-CT negative, often associated with mild hypercalcemia and had a higher persistence rate than SGD. BNE is the operation of choice in young, SPECT-CT negative patients. If ultrasound parathyroids suggests a single large adenoma, minimally invasive parathyroidectomy with intraoperative PTH monitoring can be considered.

Point-of-care diagnostics for niche applications

Point-of-care or point-of-use diagnostics are analytical devices that provide clinically relevant information without the need for a core clinical laboratory. In this review we define point-of-care diagnostics as portable versions of assays performed in a traditional clinical chemistry laboratory. This review discusses five areas relevant to human and animal health where increased attention could produce significant impact: veterinary medicine, space travel, sports medicine, emergency medicine, and operating room efficiency. For each of these areas, clinical need, available commercial products, and ongoing research into new devices are highlighted.

Imaging of the parathyroid glands in primary hyperparathyroidism

Primary hyperparathyroidism (PHPT) is one of the most frequent endocrine diseases worldwide. Surgery is the only potentially curable option for patients with this disorder, even though in asymptomatic patients 50 years of age or older without end organ complications, a conservative treatment may be a possible alternative. Bilateral neck exploration under general anaesthesia has been the standard for the definitive treatment. However, significant improvements in preoperative imaging, together with the implementation of rapid parathyroid hormone determination, have determined an increased implementation of focused, minimally invasive surgical approach. Surgeons prefer to have a localization study before an operation (both in the classical scenario and in the minimally invasive procedure). They are not satisfied by having been referred a patient with just a biochemical diagnosis of PHPT. Imaging studies must not be utilized to make the diagnosis of PHPT. They should be obtained to both assist in determining disease etiology and to guide operative procedures together with the nuclear medicine doctor and, most importantly, with the surgeon. On the contrary, apart from minimally invasive procedures in which localization procedures are an obligate choice, some surgeons believe that literature on parathyroidectomy over the past two decades reveals a bias towards localization. Therefore, surgical expertise is more important than the search for abnormal parathyroid glands.

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.

Aortopulmonary window parathyroid gland causing primary hyperparathyroidism in men type 1 syndrome

Primary hyperparathyroidism (HPT) is the most common endocrinopathy in Multiple Endocrine Neoplasia type 1 (MEN1) syndrome. Supernumerary and/or ectopic parathyroid glands, potentially causes of persistent or recurrent HPT after surgery, have been previously described. However, this is the first ever described case of ectopic parathyroid gland localized in the aortopulmunary window causing HPT in MEN1. After a consistent concordant pre-operative imaging assessment the patient, a 16 years old male affected by a severe hypercalcemia, underwent surgery. The parathyroid was found very deeply near the tracheal bifurcation, hidden by the aortic arch itself and for this reason not visible at the beginning of the dissection but only after being identified by palpation for its typical consistence. The intraoperative PTH decreased at normal level 10 min after removal of the ectopic gland. The patient remained with normal value of calcemia and PTH during the 10 months of follow-up.

Value of Prophylactic Cervical Thymectomy in Parathyroid Hyperplasia

BACKGROUND

In parathyroid hyperplasia (HPT), parathyroid glands within the cervical thymus are a cause for recurrence. As a result of differences in pathophysiology, variable practice patterns exist regarding performing bilateral cervical thymectomy (BCT) in primary hyperplasia versus hyperplasia from renal failure or familial disease. The objective of this study was to capture patients where thymic tissue was found with subtotal parathyroidectomy (PTX) and intended BCT, identify number of thymic supernumerary glands (SNGs), and determine overall cure rate.

METHODS

Retrospective review of patients with four-gland exploration and intended BCT for HPT from 2000 to 2013 was performed. Identification of thymic tissue and SNGs were determined by operative/pathology reports. Univariate analysis identified differences in cure rate for patients undergoing subtotal PTX with or without BCT.

RESULTS

Thymic tissue was found in 52 % of 328 primary HPT (19 % unilateral, 33 % bilateral), 77 % of 128 renal HPT (28 % unilateral, 49 % bilateral), and 100 % of familial HPT (24 % unilateral, 76 % bilateral) patients. Nine percent of primary, 18 % of renal, and 10 % of familial HPT patients had SNGs within thymectomy specimens. Cure rates of primary HPT patients with BCT were 99 % compared to 94 % in subtotal PTX alone. Renal HPT cure rates were 94 % with BCT compared to 89 % without BCT.

CONCLUSIONS

Renal HPT patients benefited most in cure when thymectomy was performed. Although the rate of SNGs found in primary HPT was lower than renal HPT, the cure rate mimicked the pattern in renal disease. Furthermore, the incidences of SNGs in primary and familial HPT were similar. On the basis of these data, we advocate that BCT be considered in primary HPT when thymic tissue is readily identified.

Clinicopathological correlates of hyperparathyroidism

Hyperparathyroidism is a common endocrine disorder with potential complications on the skeletal, renal, neurocognitive and cardiovascular systems. While most cases (95%) occur sporadically, about 5% are associated with a hereditary syndrome: multiple endocrine neoplasia syndromes (MEN-1, MEN-2A, MEN-4), hyperparathyroidism-jaw tumour syndrome (HPT-JT), familial hypocalciuric hypercalcaemia (FHH-1, FHH-2, FHH-3), familial hypercalciuric hypercalcaemia, neonatal severe hyperparathyroidism and isolated familial hyperparathyroidism. Recently, molecular mechanisms underlying possible tumour suppressor genes (MEN1, CDC73/HRPT2, CDKIs, APC, SFRPs, GSK3β, RASSF1A, HIC1, RIZ1, WT1, CaSR, GNA11, AP2S1) and proto-oncogenes (CCND1/PRAD1, RET, ZFX, CTNNB1, EZH2) have been uncovered in the pathogenesis of hyperparathyroidism. While bi-allelic inactivation of CDC73/HRPT2 seems unique to parathyroid malignancy, aberrant activation of cyclin D1 and Wnt/β-catenin signalling has been reported in benign and malignant parathyroid tumours. Clinicopathological correlates of primary hyperparathyroidism include parathyroid adenoma (80-85%), hyperplasia (10-15%) and carcinoma (<1-5%). Secondary hyperparathyroidism generally presents with diffuse parathyroid hyperplasia, whereas tertiary hyperparathyroidism reflects the emergence of autonomous parathyroid hormone (PTH)-producing neoplasm(s) from secondary parathyroid hyperplasia. Surgical resection of abnormal parathyroid tissue remains the only curative treatment in primary hyperparathyroidism, and parathyroidectomy specimens are frequently encountered in this setting. Clinical and biochemical features, including intraoperative PTH levels, number, weight and size of the affected parathyroid gland(s), are crucial parameters to consider when rendering an accurate diagnosis of parathyroid proliferations. This review provides an update on the expanding knowledge of hyperparathyroidism and highlights the clinicopathological correlations of this prevalent disease.