Secondary and tertiary hyperparathyroidism, state of the art surgical management

The Molecular Mechanisms Underlying the Systemic Effects Mediated by Parathormone in the Context of Chronic Kidney Disease

Chronic kidney disease (CKD) stands as a prominent non-communicable ailment, significantly impacting life expectancy. Physiopathology stands mainly upon the triangle represented by parathormone-Vitamin D-Fibroblast Growth Factor-23. Parathormone (PTH), the key hormone in mineral homeostasis, is one of the less easily modifiable parameters in CKD; however, it stands as a significant marker for assessing the risk of complications. The updated "trade-off hypothesis" reveals that levels of PTH spike out of the normal range as early as stage G2 CKD, advancing it as a possible determinant of systemic damage. The present review aims to review the effects exhibited by PTH on several organs while linking the molecular mechanisms to the observed actions in the context of CKD. From a diagnostic perspective, PTH is the most reliable and accessible biochemical marker in CKD, but its trend bears a higher significance on a patient's prognosis rather than the absolute value. Classically, PTH acts in a dichotomous manner on bone tissue, maintaining a balance between formation and resorption. Under the uremic conditions of advanced CKD, the altered intestinal microbiota majorly tips the balance towards bone lysis. Probiotic treatment has proven reliable in animal models, but in humans, data are limited. Regarding bone status, persistently high levels of PTH determine a reduction in mineral density and a concurrent increase in fracture risk. Pharmacological manipulation of serum PTH requires appropriate patient selection and monitoring since dangerously low levels of PTH may completely inhibit bone turnover. Moreover, the altered mineral balance extends to the cardiovascular system, promoting vascular calcifications. Lastly, the involvement of PTH in the Renin-Angiotensin-Aldosterone axis highlights the importance of opting for the appropriate pharmacological agent should hypertension develop.

Outcomes of subtotal parathyroidectomy for renal hyperparathyroidism

BACKGROUND

Renal hyperparathyroidism due to end-stage kidney disease is associated with considerable morbidity, and when refractory is treated with parathyroidectomy. Recurrent renal hyperparathyroidism is a major surgical complication, yet initial target parathyroid remnant size and outcomes, including rates of recurrence are not well elucidated.

METHODS

This is a single-institution retrospective cohort study of patients who underwent initial subtotal parathyroidectomy for renal hyperparathyroidism on dialysis, from 1990-2022. The subtotal parathyroidectomy was defined as resection of 3 parathyroid glands ± partial resection of the fourth gland leaving a remnant of ∼75-100 mg, and postresection intraoperative parathyroid hormone goal was 150-250 pg/mL. Clinical data were examined for outcomes.

RESULTS

Among 204 patients who met inclusion criteria, 139 (68%) had follow-up data; 58% (80/139) were women and median age was 45 years. Surgical complications included 2 hematomas (1.4%), 1 recurrent laryngeal nerve injury (<1%), and no patient required readmission for intravenous calcium. Using a target remnant size of 75-100 mg, recurrent renal hyperparathyroidism was uncommon (14/139, 10%) and arose at a median interval of 58.6 months (range, 8-180). In cases of recurrence, the postresection intraoperative parathyroid hormone level was less likely to drop <250 pg/mL (40%, 4/10 vs nonrecurrence 65%, 80/123; P = .11) with a slightly lower median decrease (70% vs 81% in nonrecurrence, P = .8); however, neither were significant. Recurrence did not occur in the 19 patients who later received kidney transplantation (P = .2).

CONCLUSION

In subtotal parathyroidectomy for renal hyperparathyroidism, use of a target 75-100 mg remnant size results in low complication rates. Durable cure appears to be more likely with renal transplantation.

Dynamic nomogram for predicting hungry bone syndrome before parathyroidectomy

PURPOSE

The objective of this study was to develop a dependable and uncomplicated prediction model utilizing clinical information readily accessible to patients before surgery. This model aimed to assess the likelihood of hungry bone syndrome occurrence in post-surgery patients with secondary hyperparathyroidism (SHPT), and to assist clinicians in adjusting treatment plans promptly.

METHODS

In this study, we constructed an online nomogram utilizing independent variables determined through multiple logistic regression to predict the probability of HBS occurrence after parathyroidectomy in patients with secondary hyperparathyroidism. To evaluate the precision and dependability of the nomogram, we used receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA).

RESULTS

Multivariate logistic regression analyses on 136 eligible patients identified age, parathyroid hormone (PTH), and blood calcium as independent HBS risk factors, which were then integrated into the nomogram. The area under ROC curve demonstrated the nomogram's strong predictive accuracy. The calibration curve demonstrates consistency between the model's prediction probability and observed probability, reflecting high prediction accuracy of the nomogram. Dynamic nomograms were found to hold significant practical clinical value as demonstrated by clinical decision analysis. It can be accessed on https://min115.shinyapps.io/dynnomapp/ .

CONCLUSION

In patients with secondary hyperparathyroidism, the dynamic nomogram based on age, parathyroid hormone, and blood calcium can more accurately predict the likelihood of HBS after parathyroidectomy, allowing doctors to make clinical decisions more quickly and adjust treatment plans in a timely manner to reduce the incidence of HBS.

Microwave ablation versus radiofrequency ablation for patients with primary and secondary hyperparathyroidism: a meta-analysis

OBJECTIVE

Thermal ablation, including microwave ablation (MWA) and radiofrequency ablation (RFA), has been recommended for the treatment of primary hyperparathyroidism (PHPT) and refractory secondary hyperparathyroidism (SHPT). This meta-analysis was conducted to evaluate the efficacy and safety of MWA and RFA in patients with PHPT and refractory SHPT.

METHODS

Databases including PubMed, EMbase, the Cochrane Library, CNKI (China National Knowledge Infrastructure), and Wanfang were searched from inception to December 5, 2022. Eligible studies comparing MWA and RFA for PHPT and refractory SHPT were included. Data were analyzed using Review Manager software, version 5.3.

RESULTS

Five studies were included in the meta-analysis. Two were retrospective cohort studies, and three were RCTs. Overall, 294 patients were included in the MWA group, and 194 patients were included in the RFA group. Compared with RFA for refractory SHPT, MWA had a shorter operation time for a single lesion (P < 0.01) and a higher complete ablation rate for a single lesion ≥ 15 mm (P < 0.01) but did not show a difference in the complete ablation rate for a single lesion < 15 mm (P > 0.05). There were no significant differences between MWA and RFA for refractory SHPT concerning parathyroid hormone (P > 0.05), calcium (P > 0.05), and phosphorus levels (P > 0.05) within 12 months after ablation, except that calcium (P < 0.01) and phosphorus levels (P = 0.02) in the RFA group were lower than those in the MWA group at one month after ablation. There was no significant difference between MWA and RFA concerning the cure rate of PHPT (P > 0.05). There were no significant differences between MWA and RFA for PHPT and refractory SHPT concerning the complications of hoarseness (P > 0.05) and hypocalcaemia (P > 0.05).

CONCLUSION

MWA had a shorter operation time for single lesions and a higher complete ablation rate for large lesions in patients with refractory SHPT. However, there was no significant difference in efficacy and safety between MWA and RFA in cases of both PHPT and refractory SHPT. Both MWA and RFA are effective treatment methods for PHPT and refractory SHPT.

[The role of calcium sensitive and vitamin D receptors in the pathogenesis of sporadic multiple parathyroid gland disease]

BACKGROUND

Sporadic multiple parathyroid gland disease is ¼ cases of primary hyperparathyroidism (PHPT). However, a single tactic for diagnosing and operating volume in patients with this variant of PHPT has not yet been developed. One of the possible directions in the search for pathogenetically substantiated methods of diagnosis and treatment is the study of the molecular genetic features of the disease and associated clinical and laboratory factors.

AIM

To study the features of the expression of calcium sensitive (CaSR) and vitamin D (VDR) receptors on the surface of parathyroid cells in primary hyperparathyroidism with solitary and multiple lesions of the parathyroid glands, as well as its changes under the influence of a decrease in the filtration function of the kidneys.

MATERIALS AND METHODS

In a single center observational prospective study with retrospective data collection, there were patients who during 2019-2021. operated on for PHPT, secondary hyperparathyroidism (SHPT) and all cases of tertiary hyperparathyroidism (THPT) operated during 2014-2021. The expression of CaSR, VDR and its relationship with the main laboratory parameters, the clinical variant of hyperparathyroidism, and the morphological substrate were studied.

RESULTS

The study included 69 patients: 19 with multiple and 25 with solitary PTG near PHPT, 15 with SHPT, 10 with THPT. A statistically significant decrease in the frequency of detection of normal expression of CaSR and VDR receptors occurs in any morphological variant of hyperparathyroidism and is observed in 93-60% of drugs. A decrease in the normal expression of CaSR in hyperplasia is detected statistically significantly less frequently than in adenoma (p≤0.01). The median expression intensity in adenoma was 2.5 (2:3), in hyperplasia 3.5 (3-4) (p≤0.01). The difference in the molecular mechanisms of the development of hyperparathyroidism with a predominance of a morphological substrate in the form of adenoma (PHPT with solitary adenoma) or hyperplasia (SHPT and PHPT with multiple PTG lesions) is realized in the frequency of maintaining normal CaSR expression in the PTG tissue. These mechanisms are implemented at the local level, their variability does not change under the influence of RRT. A common molecular genetic mechanism for the development of hyperparathyroidism with a predominance of a morphological substrate in the form of adenoma or hyperplasia has been found to reduce the frequency of maintaining normal VDR expression in PTG (up to 7-13%), p<0.01. This mechanism is implemented at the local level, its variability changes under the influence of RRT, reaching statistically significant differences in patients with THPT.

CONCLUSION

The study demonstrates the features of changes in the expression of CaSR and VDR in PHPT with multiple lesions of the parathyroid glands. The relationship between the expression of these receptors and the clinical variant of hyperparathyroidism, the morphological substrate, the main laboratory parameters, and renal function was shown.

Factors Associated With Persistent Post-transplant Hyperparathyroidism After Index Renal Transplantation

INTRODUCTION

Secondary hyperparathyroidism (SHP) is common in end-stage renal disease and may progress to persistent post-transplant hyperparathyroidism (PTHP) following renal transplantation (RT). We sought to describe the frequency and determine factors associated with the incidence of PTHP for patients undergoing RT at a single institution that restricts RT for patients with uncontrolled SHP with a parathyroid hormone (PTH) of >800pg/mL at time of initial transplant evaluation.

METHODS

We conducted a single-institution retrospective study of adults undergoing index RT from 2012 to 2020 who had a calcium and PTH level within 12 mo prior to RT and at least 6 mo following RT. PTHP was defined as calcium of >10 mg/dL with an elevated PTH > 88pg/mL at six or more months following RT. Univariate analysis and multivariable logistic regression were performed for factors associated with developing PTHP.

RESULTS

We identified 1110 patients with RT, 65 were excluded for prior RT, 549 did not have a pre-RT and post-RT calcium, and PTH laboratories for inclusion, yielding 496 for analysis. Following RT, 39 patients (7.9%) developed PTHP, compared to those who did not develop PTHP; these patients had significantly higher pre-RT PTH, pre-RT calcium, and frequency of calcimimetic therapy. In multivariable logistic regression factors significantly associated with PTHP were pre-RT calcium of more than 10 mg/dL with an odds ratio (OR) of 3.57 (95% confidence interval [CI] 1.52-8.39, P = 0.003) and pre-RT calcimimetic therapy with an OR 1.30 (95% CI 1.06-2.85, P = 0.041). Compared with patients who had a pre-RT PTH of less than 200 pg/mL, a PTH of 200-399 pg/mL increased risk of PTHP with an OR of 4.52 (95% CI 1.95-21.5, P = 0.048) and a PTH of > 400 pg/mL increased risk of PTHP with an OR of 7.17 (95% CI 1.47-34.9, P = 0.015). In this cohort, 11 patients (28.2%) with PTHP underwent parathyroidectomy (PTx) at a mean of 1.4 y post-RT (standard deviation 0.87).

CONCLUSIONS

For patients required to have a PTH < 800pg/mL for initial transplant candidacy, the subsequent incidence of PTHP is relatively low at 7.9%. Risk factors for PTHP include higher pre-RT calcium and PTH levels and pre-RT calcimimetic therapy. PTx remains underused in the treatment of PTHP. Further study is warranted to determine the optimal PTH cutoff for transplant candidacy and recommendation for PTx in patients requiring calcimimetic therapy for SHP.

A retrospective case series of the treatment of spontaneous quadriceps tendon rupture in patients with uremia and secondary hyperparathyroidism

Background

Spontaneous quadriceps tendon rupture (QTR) is a rare complication of uremia. Secondary hyperparathyroidism (SHPT) is considered the leading cause of QTR in uremia patients. QTR in patients with uremia and SHPT are treated with active surgical repair along with the treatment of SHPT using medication or parathyroidectomy (PTX). The impact of PTX for SHPT on tendon healing remains unclear. The purpose of this study was to introduce surgical procedures for QTR and to determine the functional recovery of the repaired quadriceps tendon (QT) after PTX.

Methods

Between Jan 2014 and Dec 2018, eight uremia patients underwent PTX after a ruptured QT was repaired by figure-of-eight trans-osseous sutures with an overlapping tightening suture technique. Biochemical indices were measured before and one year after PTX to evaluate the control of SHPT. The changes in bone mineral density (BMD) were determined by comparing x-ray images at pre-PTX and during follow-up. The assessment of the functional recovery of the repaired QT was conducted at the last follow-up using multiple functional parameters.

Results

Eight patients (fourteen tendons) were retrospectively evaluated at an average follow-up of 3.46 ± 1.37 years after PTX. ALP and iPTH levels one year after PTX were significantly lower than at pre-PTX (P = 0.017, P < 0.001, respectively). Although there was no statistical differences compared to pre-PTX, serum phosphorus levels decreased and returned to normal one year after PTX (P = 0.101). BMD significantly increased at the last follow-up compared to pre-PTX. The average Lysholm score was 73.5 ± 11.07 and the average Tegner activity score was 2.63 ± 1.06. The active knee ROM after repair averaged an extension of 2.85 ± 3.78° to a flexion angle of 113.21 ± 10.12°. The quadriceps muscle strength was grade IV and the mean Insall-Salvati index was 0.93 ± 0.10 in all of the knees with tendon ruptures. All patients were able to walk without external help.

Conclusions

Figure-of-eight trans-osseous sutures with an overlapping tightening suture technique is an economical and effective treatment for spontaneous QTR in patients with uremia and SHPT. PTX may promote tendon-bone healing in patients with uremia and SHPT.

Limited disease progression in endocrine surgery patients with treatment delays due to COVID-19

BACKGROUND

The COVID-19 pandemic profoundly impacted the delivery of care and timing of elective surgical procedures. Most endocrine-related operations were considered elective and safe to postpone, providing a unique opportunity to assess clinical outcomes under protracted treatment plans.

METHODS

American Association of Endocrine Surgeon members were surveyed for participation. A Research Electronic Data Capture survey was developed and distributed to 27 institutions to assess the impact of COVID-19-related delays. The information collected included patient demographics, primary diagnosis, resumption of care, and assessment of disease progression by the surgeon.

RESULTS

Twelve out of 27 institutions completed the survey (44.4%). Of 850 patients, 74.8% (636) were female; median age was 56 (interquartile range, 44-66) years. Forty percent (34) of patients had not been seen since their original surgical appointment was delayed; 86.2% (733) of patients had a delay in care with women more likely to have a delay (87.6% vs 82.2% of men, χ² = 3.84, P = .05). Median duration of delay was 70 (interquartile range, 42-118) days. Among patients with a delay in care, primary disease site included thyroid (54.2%), parathyroid (37.2%), adrenal (6.5%), and pancreatic/gastrointestinal neuroendocrine tumors (1.3%). In addition, 4.0% (26) of patients experienced disease progression and 4.1% (24) had a change from the initial operative plan. The duration of delay was not associated with disease progression (P = .96) or a change in operative plan (P = .66).

CONCLUSION

Although some patients experienced disease progression during COVID-19 delays to endocrine disease-related care, most patients with follow-up did not. Our analysis indicated that temporary delay may be an acceptable course of action in extreme circumstances for most endocrine-related surgical disease.

Hyperparathyroidism at 1 year after kidney transplantation is associated with graft loss

BACKGROUND

Hyperparathyroidism persists in many patients after kidney transplantation. The purpose of this study was to evaluate the association between post-transplant hyperparathyroidism and kidney transplantation outcomes.

METHODS

We identified 824 participants from a prospective longitudinal cohort of adult patients who underwent kidney transplantation at a single institution between December 2008 and February 2020. Parathyroid hormone levels before and after kidney transplantation were abstracted from medical records. Post-transplant hyperparathyroidism was defined as parathyroid hormone level ≥70 pg/mL 1 year after kidney transplantation. Cox proportional hazards models were used to estimate the adjusted hazard ratios of mortality and death-censored graft loss by post-transplant hyperparathyroidism. Models were adjusted for age, sex, race/ethnicity, college education, parathyroid hormone level before kidney transplantation, cause of kidney failure, and years on dialysis before kidney transplantation. A Wald test for interactions was used to evaluate the risk of death-censored graft loss by age, sex, and race.

RESULTS

Of 824 recipients, 60.9% had post-transplant hyperparathyroidism. Compared with non-hyperparathyroidism patients, those with post-transplant hyperparathyroidism were more likely to be Black (47.2% vs 32.6%), undergo dialysis before kidney transplantation (86.9% vs 76.6%), and have a parathyroid hormone level ≥300 pg/mL before kidney transplantation (26.8% vs 9.5%) (all P < .001). Patients with post-transplant hyperparathyroidism had a 1.6-fold higher risk of death-censored graft loss (adjusted hazard ratio = 1.60, 95% confidence interval: 1.02-2.49) compared with those without post-transplant hyperparathyroidism. This risk more than doubled in those with parathyroid hormone ≥300 pg/mL 1 year after kidney transplantation (adjusted hazard ratio = 4.19, 95% confidence interval: 1.95-9.03). The risk of death-censored graft loss did not differ by age, sex, or race (all Pinteraction > .05). There was no association between post-transplant hyperparathyroidism and mortality.

CONCLUSION

The risk of graft loss was significantly higher among patients with post-transplant hyperparathyroidism when compared with patients without post-transplant hyperparathyroidism.

Localization and surgical approach to mediastinal parathyroid glands

BACKGROUND

Hyperactive parathyroid glands (PTGs) are in the mediastinum 4.3% of the time. Historically, localization and resection of these glands can be challenging.

METHODS

We searched all operative notes involving a thoracic surgeon and a preoperative diagnosis of hyperparathyroidism from 2001 to 2019.

RESULTS

Eighty-five cases were reviewed, of which 63 were included. Only 14 patients (22%) had de novo hyperparathyroid operations. Seventeen patients (27%) had single-photon emission computed tomography with computed tomography fusion (SPECT-CT) as the only preoperative localization test (excluding chest radiography and ultrasound), and all were resected successfully. The initial surgical approach was transcervical for 16 (27%) patients, however only 7 remained transcervical. 4 (6%) patients had an exploration in which the target lesion was resected but it was not parathyroid tissue.

CONCLUSION

Most patients presenting with mediastinal PTG have had prior HPT surgery. The trend toward more focused HPT surgery may mean more de novo mediastinal PTG resections. An unambiguous functional and anatomic localization test, such as a spect-ct scan, is the best predictor of a successful resection. Ambiguous or discordant scans should be approached cautiously, and additional confirmatory tests are recommended. For suspected PTG located in the thymus, the thoracic surgeon should choose the most familiar approach to achieve complete thymectomy.

Alendronate treatment in cats with persistent ionized hypercalcemia: A retrospective cohort study of 20 cases

BACKGROUND

Limited information is available concerning treatment of ionized hypercalcemia in cats.

HYPOTHESIS/OBJECTIVES

Describe clinical findings in a cohort of cats with persistent ionized hypercalcemia and evaluate long-term tolerance and efficacy of alendronate in these patients.

ANIMALS

Twenty cats with persistent ionized hypercalcemia of undetermined origin, presented for routine or referral consultation at the teaching hospital of Maisons-Alfort (France).

METHODS

Medical records were retrospectively reviewed. Cats were divided into Group 1 (cats that received alendronate as well as other treatments, n = 11) and Group 2 (cats that did not receive alendronate, n = 9). Survival analysis (Kaplan-Meier method, log-rank test, and Cox proportional hazard models) was conducted to compare time to selected outcomes.

RESULTS

Azotemia was present in 15 cats (75%). Alendronate treatment was administered and well tolerated during the entire follow-up period (median, 9.5 months; interquartile range [IQR], 6.3; 27) in all cats from Group 1, except in 1 cat that developed severe hypophosphatemia, prompting treatment discontinuation. Univariate analysis determined that alendronate treatment was significantly associated with shorter time to reach a 15% decrease in ionized calcium concentration (iCa) from baseline during follow-up (119 days vs median not reached, P = .02). This association was no longer significant after adjustment for age and initial iCa.

CONCLUSIONS AND CLINICAL IMPORTANCE

Alendronate overall was well tolerated with chronic use in this cohort, and can be considered a treatment option for persistent ionized hypercalcemia in cats.

The American Association of Endocrine Surgeons Guidelines for the Definitive Surgical Management of Secondary and Tertiary Renal Hyperparathyroidism

OBJECTIVE

To develop evidence-based recommendations for safe, effective, and appropriate treatment of secondary (SHPT) and tertiary (THPT) renal hyperparathyroidism.

BACKGROUND

Hyperparathyroidism is common among patients with chronic kidney disease, end-stage kidney disease, and kidney transplant. The surgical management of SHPT and THPT is nuanced and requires a multidisciplinary approach. There are currently no clinical practice guidelines that address the surgical treatment of SHPT and THPT.

METHODS

Medical literature was reviewed from January 1, 1985 to present January 1, 2021 by a panel of 10 experts in SHPT and THPT. Recommendations using the best available evidence was constructed. The American College of Physicians grading system was used to determine levels of evidence. Recommendations were discussed to consensus. The American Association of Endocrine Surgeons membership reviewed and commented on preliminary drafts of the content.

RESULTS

These clinical guidelines present the epidemiology and pathophysiology of SHPT and THPT and provide recommendations for work-up and management of SHPT and THPT for all involved clinicians. It outlines the preoperative, intraoperative, and postoperative management of SHPT and THPT, as well as related definitions, operative techniques, morbidity, and outcomes. Specific topics include Pathogenesis and Epidemiology, Initial Evaluation, Imaging, Preoperative and Perioperative Care, Surgical Planning and Parathyroidectomy, Adjuncts and Approaches, Outcomes, and Reoperation.

CONCLUSIONS

Evidence-based guidelines were created to assist clinicians in the optimal management of secondary and tertiary renal hyperparathyroidism.

Machine Learning-Derived Integer-Based Score and Prediction of Tertiary Hyperparathyroidism among Kidney Transplant Recipients: An Integer-Based Score to Predict Tertiary Hyperparathyroidism

BACKGROUND AND OBJECTIVES

Tertiary hyperparathyroidism in kidney allograft recipients is associated with bone loss, allograft dysfunction, and cardiovascular mortality. Accurate pretransplant risk prediction of tertiary hyperparathyroidism may support individualized treatment decisions. We aimed to develop an integer score system that predicts the risk of tertiary hyperparathyroidism using machine learning algorithms.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We used two separate cohorts: a derivation cohort with the data of kidney allograft recipients (n=669) who underwent kidney transplantation at Severance Hospital, Seoul, Korea between January 2009 and December 2015 and a multicenter registry dataset (the Korean Cohort Study for Outcome in Patients with Kidney Transplantation) as an external validation cohort (n=542). Tertiary hyperparathyroidism was defined as post-transplant parathyroidectomy. The derivation cohort was split into 75% training set (n=501) and 25% holdout test set (n=168) to develop prediction models and integer-based score.

RESULTS

Tertiary hyperparathyroidism requiring parathyroidectomy occurred in 5% and 2% of the derivation and validation cohorts, respectively. Three top predictors (dialysis duration, pretransplant intact parathyroid hormone, and serum calcium level measured at the time of admission for kidney transplantation) were identified to create an integer score system (dialysis duration, pretransplant serum parathyroid hormone level, and pretransplant calcium level score [DPC]; 0-15 points) to predict tertiary hyperparathyroidism. The median DPC score was higher in participants with post-transplant parathyroidectomy than in those without (13 versus three in derivation; 13 versus four in external validation; P<0.001 for all). Pretransplant dialysis duration, pretransplant serum parathyroid hormone level, and pretransplant calcium level score predicted post-transplant parathyroidectomy with comparable performance with the best-performing machine learning model in the test set (area under the receiver operating characteristic curve: 0.94 versus 0.92; area under the precision-recall curve: 0.52 versus 0.47). Serial measurement of DPC scores (≥13 at least two or more times, 3-month interval) during 12 months prior to kidney transplantation improved risk classification for post-transplant parathyroidectomy compared with single-time measurement (net reclassification improvement, 0.28; 95% confidence interval, 0.02 to 0.54; P=0.03).

CONCLUSIONS

A simple integer-based score predicted the risk of tertiary hyperparathyroidism in kidney allograft recipients, with improved classification by serial measurement compared with single-time measurement.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Korean Cohort Study for Outcome in Patients with Kidney Transplantation (KNOW-KT), NCT02042963 PODCAST: This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2022_06_10_CJN15921221.mp3.

Tertiary hyperparathyroidism in patients with pseudohypoparathyroidism type 1a

Pseudohypoparathyroidism type 1a (PHP1a) is a genetic disorder caused by heterozygous loss-of-function mutations on the maternal allele of the GNAS gene. Patients with PHP1a predominantly exhibit parathyroid hormone (PTH) resistance and physical features of Albright's hereditary osteodystrophy. We report two unrelated cases with PHP1a who developed tertiary hyperparathyroidism (HPT). Molecular analyses of the GNAS gene identified a previously known heterozygous 4-bp deletion (c. 565_568delGACT) in exon 7 in case 1 and a novel heterozygous missense mutation (p.Lys233Glu) in exon 9 in case 2. Both patients developed tertiary HPT associated with hyperfunctioning parathyroid glands during long-term treatment of hypocalcemia. Case 1 had severe osteoporosis and underwent parathyroidectomy. Case 2 was asymptomatic with no evidence of bone diseases associated with tertiary HPT. PHP1a patients are at risk of developing tertiary HPT and should be treated with sufficient doses of calcium and vitamin D to achieve serum PTH levels within the mid - normal to double the upper limit of the normal range, regardless of serum calcium levels.

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Pseudohypoparathyroidism type 1a induces tertiary hyperparathyroidism.

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Tertiary hyperparathyroidism can be complicated by hungry bone syndrome.

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Serum PTH levels should be within doubled the upper limit of normal.

Surgery is Underutilized in the Management of Tertiary Hyperparathyroidism

INTRODUCTION

Tertiary hyperparathyroidism (3HPT) is observed in up to 40% of renal transplant patients. Standard guidelines defining 3HPT and indications for operative intervention are not well described.

METHODS

We conducted a retrospective, single-institution cohort study of patients who underwent renal transplant between January 1, 2012 and January 30, 2018, with a minimum of 13-month follow-up and at least 1 y of allograft function. We defined 3HPT as having elevated serum level parathyroid hormone (>88 pg/mL) after successful renal transplantation or multiple instances of elevated serum calcium starting at least 3 mo after transplant. We compared graft failure rates after stratifying the cohort based on management strategy: expectant, medical management with cinacalcet, and parathyroidectomy.

RESULTS

Out of the 381 transplanted patients with functional grafts at 1 y, 178 patients (46.6%) were found to have 3HPT. One hundred twenty-nine patients (72.5%) were managed expectantly without medications, 35 patients (19.7%) were managed medically, and 14 patients (7.8%) were managed with parathyroidectomy. Twenty-two patients (17.1%) in the observation group had graft failure, 4 patients (11.4%) in the medically managed group had graft failure, and 0 patients in the surgery group had graft failure. Surgical intervention was associated with decreased renal allograft failure when compared to the combined cohort of nonoperative 3HPT patients (P = 0.03). All patients who underwent parathyroidectomy were cured and did not have graft failure as of December 30, 2019. Calcium elevation, but not PTH elevation, was associated with referral for parathyroidectomy on multivariable logistic regression analysis (P < 0.01).

CONCLUSIONS

At our institution, the referral rate for parathyroidectomy among patients with 3HPT remains low. Parathyroidectomy was associated with high cure rates and reduced graft failure. Surgery may be underutilized in the management of 3HPT.

A pilot feasibility study to assess vascularity and perfusion of parathyroid glands using a portable hand-held imager

OBJECTIVES

Intraoperative localization and preservation of parathyroid glands (PGs) are challenging during thyroid surgery. A new noninvasive technique of combined near-infrared PG autofluorescence detection and dye-free imaging angiography that allows intraoperative feedback has recently been introduced. The objective of this study was to evaluate this technique in real-time.

MATERIALS AND METHODS

A pilot feasibility study of a portable imaging device in four patients who underwent either thyroid lobectomy or total thyroidectomy is presented. PG autofluorescence and vascularity/tissue perfusion were monitored using a real-time screen display during the surgical procedure.

RESULTS

Three lobectomies and one total thyroidectomy were performed. Among the nine PGs identified by the operating surgeon, eight PGs were confirmed using the autofluorescence device. Each PG was successfully determined to be either well-perfused or devascularized, and devascularized PGs were autotransplanted.

CONCLUSIONS

The preliminary results suggest that the combination of PG autofluorescence detection and dye-free angiography can potentially be used to assess PG function. With further validation studies, the effectiveness of this technique in clinical practice can be further delineated.

Prevalence and risk factors for tertiary hyperparathyroidism in kidney transplant recipients

BACKGROUND

Tertiary hyperparathyroidism after kidney transplantation has been associated with graft dysfunction, cardiovascular morbidity, and osteopenia; however, its true prevalence is unclear. The objective of our study was to evaluate the prevalence of and risk factors for tertiary hyperparathyroidism.

METHODS

A prospective cohort of 849 adult kidney transplantation recipients (December 2008-February 2020) was used to estimate the prevalence of hyperparathyroidism 1-year post-kidney transplant. Tertiary hyperparathyroidism was defined as hypercalcemia (≥10mg/dL) and hyperparathyroidism (parathyroid hormone≥70pg/mL) 1-year post-kidney transplantation. Modified Poisson regression models were used to evaluate risk factors associated with the development of both persistent hyperparathyroidism and tertiary hyperparathyroidism.

RESULTS

Among kidney transplantation recipients, 524 (61.7%) had persistent hyperparathyroidism and 182 (21.5%) had tertiary hyperparathyroidism at 1-year post-kidney transplantation. Calcimimetic use before kidney transplantation was associated with 1.30-fold higher risk of persistent hyperparathyroidism (adjusted prevalence ratio = 1.30, 95% CI: 1.12-1.51) and 1.84-fold higher risk of tertiary hyperparathyroidism (adjusted prevalence ratio = 1.84, 95% CI: 1.25-2.72). Pre-kidney transplantation parathyroid hormone ≥300 pg/mL was associated with 1.49-fold higher risk of persistent hyperparathyroidism (adjusted prevalence ratio = 1.49, 95% CI = 1.19-1.85) and 2.21-fold higher risk of tertiary hyperparathyroidism (adjusted prevalence ratio = 2.21, 95% CI = 1.25-3.90). Pre-kidney transplantation tertiary hyperparathyroidism was associated with an increased risk of post-kidney transplantation tertiary hyperparathyroidism (adjusted prevalence ratio = 1.71, 95% CI = 1.29-2.27), but not persistent hyperparathyroidism. Furthermore, 73.0% of patients with persistent hyperparathyroidism and 61.5% with tertiary hyperparathyroidism did not receive any treatment at 1-year post-kidney transplantation.

CONCLUSION

Persistent hyperparathyroidism affected 61.7% and tertiary hyperparathyroidism affected 21.5% of kidney transplantation recipients; however, the majority of patients were not treated. Pre-kidney transplantation parathyroid hormone levels ≥300pg/mL and the use of calcimimetics are associated with the development of tertiary hyperparathyroidism. These findings encourage the re-evaluation of recommended pre-kidney transplantation parathyroid hormone thresholds and reconsideration of pre-kidney transplantation secondary hyperparathyroidism treatments to avoid the adverse sequelae of tertiary hyperparathyroidism in kidney transplantation recipients.

OUP accepted manuscript

Chronic kidney disease mineral and bone disorder may persist after successful kidney transplantation. Persistent hyperparathyroidism has been identified in up to 80% of patients throughout the first year after kidney transplantation. International guidelines lack strict recommendations about the management of persistent hyperparathyroidism. However, it is associated with adverse graft and patient outcomes, including higher fracture risk and an increased risk of all-cause mortality and allograft loss. Secondary hyperparathyroidism may be treated medically (vitamin D, phosphate binders and calcimimetics) or surgically (parathyroidectomy). Guideline recommendations suggest medical therapy first but do not clarify optimal parathyroid hormone targets or indications and timing of parathyroidectomy. There are no clear guidelines or long-term studies about the impact of hyperparathyroidism therapy. Parathyroidectomy is more effective than medical treatment, although it is associated with increased short-term risks. Ideally parathyroidectomy should be performed before kidney transplantation to prevent persistent hyperparathyroidism and improve graft outcomes. We now propose a roadmap for the management of secondary hyperparathyroidism in patients eligible for kidney transplantation that includes the indications and timing (pre- or post-kidney transplantation) of parathyroidectomy, the evaluation of parathyroid gland size and the integration of parathyroid gland size in the decision-making process by a multidisciplinary team of nephrologists, radiologists and surgeons.

Data to inform counseling on parathyroidectomy for secondary hyperparathyroidism of renal origin

BACKGROUND

The risk of postoperative hungry bone syndrome after parathyroidectomy for secondary hyperparathyroidism of renal origin may alter the course of treatment, including the hospital length of stay and readmission rates. We sought to identify additional patient or hospital factors that might contribute to hungry bone syndrome after parathyroidectomy in patients with secondary hyperparathyroidism of renal origin.

METHODS

Patients who underwent a parathyroidectomy for secondary hyperparathyroidism of renal origin were identified in a geographically diverse, 10-state, discharge data set. Covariates included demographic data, payer status, 31 comorbidities, and hospital characteristics. The primary outcome variable of interest was hospital length of stay. Secondary outcomes were complications and 30-day readmission.

RESULTS

Of 796 patients studied, 164 patients (20.6%) were diagnosed with hungry bone syndrome. There were no differences in the rates of hungry bone syndrome by race or number of comorbidities. The average age of hungry bone syndrome patients (45.7 years ± 13.9) was younger than that of non-hungry bone syndrome patients (50.7 ± 14.8; P < .001). Hungry bone syndrome was more common among obese patients than nonobese patients (25.0% vs 15.8%; P < .001). Parathyroid autotransplant was performed at similar rates in hungry bone syndrome and non-hungry bone syndrome patients (23.8% vs 23.1%; P = .821). Median length of stay was significantly longer for hungry bone syndrome patients (6 days, interquartile range: [4, 8] versus 3 days, interquartile range: [2-6]; P < .001). Similar 30-day readmission rates were observed (hungry bone syndrome: 41 (25%) versus non-hungry bone syndrome: 147 (23%); P = .640).

CONCLUSION

Hungry bone syndrome occurs in 1 of 5 patients after parathyroidectomy for secondary hyperparathyroidism of renal origin. Patients should be informed of the possibility of a relatively long (6 days) length of stay after surgery as well as the moderate possibility (>20%) of another hospitalization within the 30-day postdischarge period.

Association Between Treatment of Secondary Hyperparathyroidism and Posttransplant Outcomes

BACKGROUND

Secondary hyperparathyroidism (SHPT) affects nearly all patients on maintenance dialysis therapy. SHPT treatment options have considerably evolved over the past 2 decades but vary in degree of improvement in SHPT. Therefore, we hypothesize that the risks of adverse outcomes after kidney transplantation (KT) may differ by SHPT treatment.

METHODS

Using the Scientific Registry of Transplant Recipients and Medicare claims data, we identified 5094 adults (age ≥18 y) treated with cinacalcet or parathyroidectomy for SHPT before receiving KT between 2007 and 2016. We quantified the association between SHPT treatment and delayed graft function and acute rejection using adjusted logistic models and tertiary hyperparathyroidism (THPT), graft failure, and death using adjusted Cox proportional hazards; we tested whether these associations differed by patient characteristics.

RESULTS

Of 5094 KT recipients who were treated for SHPT while on dialysis, 228 (4.5%) underwent parathyroidectomy, and 4866 (95.5%) received cinacalcet. There was no association between treatment of SHPT and posttransplant delayed graft function, graft failure, or death. However, compared with patients treated with cinacalcet, those treated with parathyroidectomy had a lower risk of developing THPT (adjusted hazard ratio, 0.56; 95% confidence interval, 0.35-0.89) post-KT. Furthermore, this risk differed by dialysis vintage (Pinteraction = 0.039). Among patients on maintenance dialysis therapy for ≥3 y before KT (n = 3477, 68.3%), the risk of developing THPT was lower when treated with parathyroidectomy (adjusted hazard ratio, 0.43; 95% confidence interval, 0.24-0.79).

CONCLUSIONS

Parathyroidectomy should be considered as treatment for SHPT, especially in KT candidates on maintenance dialysis for ≥3 y. Additionally, patients treated with cinacalcet for SHPT should undergo close surveillance for development of tertiary hyperparathyroidism post-KT.

Analyzing Genetic Differences Between Sporadic Primary and Secondary/Tertiary Hyperparathyroidism by Targeted Next-Generation Panel Sequencing

Secondary hyperparathyroidism (SHPT) is characterized by excessive serum parathyroid hormone levels in response to decreasing kidney function, and tertiary hyperparathyroidism (THPT) is often the result of a long-standing SHPT. To date, several genes have been associated with the pathogenesis of primary hyperparathyroidism (PHPT). However, the molecular genetic mechanisms of uremic hyperparathyroidism (HPT) remain uncharacterized. To elucidate the differences in genetic alterations between PHPT and SHPT/THPT, the targeted next-generation sequencing of genes associated with HPT was performed using DNA extracted from parathyroid tissues. As a result, 26 variants in 19 PHPT or SHPT/THPT appeared as candidate pathogenic mutations, which corresponded to 9 (35%) nonsense, 8 (31%) frameshift, 6 (23%) missense, and 3 (11%) splice site mutations. The MEN1 (23%, 6/26), ASXL3 (15%, 4/26), EZH2 (12%, 3/26), and MTOR (8%, 2/26) genes were frequently mutated. Sixteen of 25 patients with PHPT (64%) had one or more mutations, whereas 3 (21%) of 21 patients with SHPT/THPT had only 1 mutation (p = 0.001). Sixteen of 28 patients (57%) with parathyroid adenoma (PA) had one or more mutations, whereas 3 of 18 patients (17%) with parathyroid hyperplasia (PH) had just one mutation (p = 0.003). Known driver mutations associated with parathyroid tumorigenesis such as CCND1/PRAD1, CDC73/HRPT2, and MEN1 were identified only in PA (44%, 7/16 with mutations). Our results suggest that molecular genetic abnormalities in SHPT/THPT are distinct from those in PHPT. These findings may help in analyzing the molecular pathogenesis underlying uremic HPT development.

Outcomes of Subtotal Parathyroidectomy Versus Total Parathyroidectomy With Autotransplantation for Tertiary Hyperparathyroidism: Multi-institutional Study

OBJECTIVES

Due to the paucity of data and controversy regarding the preferred surgical approach for managing tertiary HPT, we sought to investigate the outcomes of different surgical approaches in managing this challenging disease.

METHODS

We performed a multi-center retrospective study to include patients with tertiary HPT who underwent STPX or total parathyroidectomy with autotransplantation (TPX-A).

RESULTS

One hundred five patients had kidney transplant, and 43 were on dialysis. In the kidney transplant group, 61 patients underwent STPX, and 44 for TPX-A. Patients' demographics were not significantly different (48.61 ± 9.31 vs 47.95 ± 12.73 years, P = 0.759. The postoperative follow-up showed that the TPX-A cohort had a higher rate of hypoparathyroidism (N = 20, 45.45%) versus (N = 14, 22.95%) with the STPX cohort (P = 0.013). The cure among the TPX-A cohorts (84.09%) over the STPX cohort (73.77%) (P = 0.153). The long-term follow-up showed that the rate of developing temporary (N = 16, 41.03%) or permanent (N = 8, 20.51%) hypoparathyroidism was significantly higher among patients who underwent TPX-A over the patients who underwent STPX (N = 7, 17.95%), and (N = 4, 10.26%), respectively (P = 0.012). There was no statistical difference between the persistence (N = 3, 7.69%) or the recurrence (N = 2, 5.13%) of the HPT in the TPX-A cohort and the STPX cohort (N = 2, 5.13%). (N = 4, 10.26%), respectively, P = 0.644.

CONCLUSIONS

To our knowledge, this is the largest multi-center study that compared different approaches for managing tertiary HPT. Showing that STPX is the better modality in patients diagnosed with tertiary HPT and had kidney transplants avoiding the risk of hypoparathyroidism.

Parathyroid Surgery: What Radiologists Need to Know

Surgical intervention remains the mainstay of treatment of hyperparathyroidism and provides the highest chance at cure. After the disease is confirmed by biochemical testing, surgeons must use a combination of patient clinical history and radiographic imaging to determine the most appropriate surgical strategy. Through either minimally invasive parathyroidectomy or bilateral cervical exploration, surgeons provide high rates of cure for hyperparathyroidism with low rates of persistence or recurrence.

Imaging features of hypercalcemia: A primer for emergency radiologists

Hypercalcemia is a marker for a wide variety of underlying etiologies, and its presentation in the emergency setting may be asymptomatic, incidental, or a primary complaint with associated symptoms and physical exam findings. While the workup is initially driven through serum laboratory testing, imaging plays an important role in diagnosis and post-treatment follow up. This review covers multiple common and uncommon etiologies of hypercalcemia, details their underlying mechanisms, and identifies the most important associated imaging findings. It is important for radiologists to be familiar with these etiologies and imaging findings, particularly in the emergency setting since hypercalcemia may represent the only significant laboratory abnormality associated with the presenting condition. Furthermore, the radiologist's interpretation of a study may be directly influenced by knowing about a patient's hypercalcemia.

The Usefulness of Intraoperative PTH as a Predictor for Successful Parathyroidectomy in Secondary Hyperparathyroidism

Introduction: Secondary hyperparathyroidism (SHPT) is a multisystemic syndrome that affects calcium and bone homeostasis in patients with chronic kidney disease (CKD). Despite medical treatment, 1–2% of patients require parathyroidectomy annually. The use of an intraoperative parathormone protocol (IOPTH) to predict cure is still in debate, due to the lack of standardized protocols, the use of different assays, and uneven PTH clearance. This study aimed to determine the diagnostic accuracy of an IOPTH in patients with SHPT for predicting successful surgery after parathyroidectomy.

Methods: About 30 patients were enrolled. A prospective observational study (cohort) was performed in patients who were submitted to parathyroidectomy by an endocrine surgeon for SHPT. All were submitted to a bilateral neck exploration with a subtotal parathyroidectomy. Three IOPTH determinations were withdrawn: at anesthetic induction (PTH₀), 15 min (PTH₁₅), and 30 min (PTH₃₀) after completion of gland resection. Another sample was taken 24 h after the procedure (PTH₂₄), values <150 pg/mL defined a successful surgery, and patients were assigned to the success or failure group. IOPTH drop was analyzed to predict successful surgery with drops of 70 and 90% at 15 and 30 min, respectively.

Results: A total of 26 patients were included, 19 patients were in the successful group. IOPTH showed a significant difference between groups in their absolute PTH₁₅ and PTH₃₀ values. A significant difference was also found in their PTH drop at 30 min (81 vs. 91%, p = 0.08). For predicting a successful surgery, having a PTH drop >90% at 30 min was the most significant factor [Odds Ratio (OR) 3.0 (1.5–4) IC 95%].

Conclusions: This study points toward a stricter and staggered IOPTH protocol to predict a successful surgery. Our results suggest taking a PTH₁₅ expecting a PTH drop of >90%. If this is not achieved, reexploration and a PTH₃₀ sample are suggested to accurately predict success.

Advances in the diagnosis and the management of primary hyperparathyroidism

The parathyroid glands, one of the last organs to be discovered, are responsible for maintaining calcium homeostasis, and they continue to present the clinician with diagnostic and management challenges that are reviewed herein. Primary hyperparathyroidism (PHPT) comprises the vast majority of pathology of the parathyroid glands. The classic variant, presenting with elevated calcium and parathyroid hormone levels, has been studied extensively, but the current body of literature has added to our understanding of normocalcemic and normohormonal variants of PHPT, as well as syndromic forms of PHPT. All variants can lead to bone loss, kidney stones, declining renal function, and a variety of neurocognitive, gastrointestinal, and musculoskeletal complaints, although the majority of PHPT today is asymptomatic. Surgery remains the definitive treatment for PHPT, and advances in screening, evolving indications for surgery, new imaging modalities, and improvements in intra-operative methods have greatly changed the landscape. Surgery continues to produce excellent results in the hands of an experienced parathyroid surgeon. For those patients who are not candidates for surgery, therapeutic advances in medical management allow for improved control of the hypercalcemic state. Parathyroid cancer is extremely rare; the diagnosis is often made intra-operatively or on final pathology, and recurrence is common. The mainstay of treatment is normalization of serum calcium via surgery and medical adjuncts.

Practice variation in the treatment of patients with renal hyperparathyroidism: a survey-based study in the Netherlands

Background

Renal hyperparathyroidism is a disease entity that is complex and poorly understood. Although there are guidelines regarding how to manage this patient group, evidence is scarce. Therefore, this survey-based study aims to map the physicians’ attitude in terms of preference for management of renal hyperparathyroidism and the influence of patient and respondent factors.

Methods

A survey was sent to Dutch societies of nephrology, endocrinology, and surgeons with interest in endocrine surgery. The survey consisted of eight case vignettes of renal hyperparathyroidism patients who were on hemodialysis and suitable for kidney transplantation, and varied in one of three patient variables import for decision making: age (40 vs. 65 years), parathyroid hormone (40 vs. 90 pmol/L), and serum calcium level (2.25 vs. 2.8 mmol/L). For each case, respondents could choose between maintaining conservative treatment (active vitamin D metabolites), calcimimetics, or subtotal parathyroidectomy as their treatment of choice. Categorical multilevel logistic models were used to investigate the association of patient and respondent variables with treatment preference. The influence of patient variables was determined independently of each other and by means of logistic regression the probabilities of treatment choice were calculated.

Results

In total, 115 surveys were included in the analysis. In 6 out of 8 cases, less than two-thirds of respondents agreed on the most favoured treatment. Among patient characteristics, the main disincentive for respondents not to choose conservative therapy was an elevated serum calcium level (subtotal parathyroidectomy vs conservative OR 93.1, 95%-CI: 48.39–179.07 and calcimimetics vs conservative OR 31.2 95%-CI: 18.58–52.30). Additionally, the most significant treatment differences were found between medical specialties and the experience of the respondents, expressed as the amount of cases the physician was involved in during the past year.

Conclusions

Elevated serum calcium levels were widely recognized and the prime reason for respondents to abandon conservative treatment. However, considerable disagreement in treatment preferences remained throughout the cases, demonstrating the current literature available being inconclusive in guiding physicians. Therefore, a high-quality trial comparing subtotal parathyroidectomy to medical treatment is needed to determine optimal treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02361-7.

Parathyroidectomy or cinacalcet: Do we still not know the best option for graft function in kidney-transplanted patients? A meta-analysis

BACKGROUND

Tertiary hyperparathyroidism occurs in 25% to 50% of kidney-transplanted patients. Indication of parathyroidectomy is now discussed, since the calcimimetic agent, cinacalcet, is an alternate option. The effects of either of these treatments on graft function remain controversial, studied only in small cohorts showing either decrease or absence of modification. We performed a meta-analysis to evaluate the evolution of graft function after surgical or medical treatment.

METHODS

Studies assessing graft function in tertiary hyperparathyroidism after parathyroidectomy or cinacalcet introduction were enrolled into quantitative analysis using Pubmed, Embase, and Cochrane databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis reporting guidelines. Among 68 screened studies, 18 had no missing data and were included for statistical analyses. We performed random effect meta-analysis to determine changes in serum creatinine and estimated glomerular filtration rate.

RESULTS

Seven studies assessing the evolution of graft function 6 and/or 12 months after parathyroidectomy and 13 after administration of cinacalcet were included. Meta-analysis found no significant variations after parathyroidectomy in serum creatinine (6 studies, 314 patients) and estimated glomerular filtration rate (2 studies, 105 patients). No significant variation was found after administration of cinacalcet in serum creatinine (10 studies, 404 patients) and estimated glomerular filtration rate (6 studies, 149 patients). A significant heterogeneity between the studies (P < .01, Cochran's Q) was found.

CONCLUSION

Meta-analysis shows that parathyroidectomy and cinacalcet do not significantly impair graft function in patients with tertiary hyperparathyroidism. However, the significant heterogeneity between selected studies, partially explained by the lack of consensual definition of tertiary hyperparathyroidism, limits the conclusions of all previously published series.

Two parathyroid adenomas in a Saudi female on hemodialysis diagnosed with tertiary hyperparathyroidism: a case report

A case of a 51-year-old female on hemodialysis 3 times per week for the past seven years was admitted to the endocrine surgery department on July of 2018 in Al-Hada Armed Forces hospital in Taif city, Saudi Arabia. Presented with complains of bone ache in her hip and lower limbs. Her labs showed that parathyroid hormone (PTH) has reached 4,267.2 pg/mL and her calcium was 2.82 mmol/L, phosphate was 0.84. Her case was suggesting Tertiary Hyperparathyroidism (HPT). She was scheduled for total parathyroidectomy. Histopathological analysis of the resected parathyroid glands confirmed the presence of two parathyroid adenomas. Retrospective progression of PTH, calcium and phosphate were documented, starting from the time she started the hemodialysis seven years ago and it eliminated the presence of preexisting functioning adenomas prior to the kidney failure. The development of multiple parathyroid adenomas in a patient with Tertiary HPT who is on hemodialysis is rare with only one study of a similar case in Japan in 1982. We present a rare case of Tertiary HPT patient on hemodialysis for seven years with double parathyroid adenomas that developed after the establishment of kidney failure. This case may give some insight to the factors that might lead to the formation of parathyroid adenomas, and it provides a unique follow-up of biochemical parameters during 7 years of parathyroid adenomas development.

Hiperparatiroidismo primario: conceptos para el cirujano general

Durante las últimas décadas, la incidencia del hiperparatiroidismo primario ha venido en aumento, muy probablemente relacionado con la mayor accesibilidad a los estudios diagnósticos; sin embargo, la forma más común de presentación clínica del hiperparatiroidismo primario es asintomática, en más del 80% de los pacientes. En la actualidad, es menos frecuente el diagnóstico por las complicaciones renales (urolitiasis) u óseas (osteítis fibrosa quística) asociadas. Un tumor benigno de la glándula paratiroides (adenoma único), es la principal causa de esta enfermedad. Por tanto, su tratamiento usualmente es quirúrgico. A pesar de ello, no es frecuente el manejo de esta patología por el cirujano general. En este artículo se revisan conceptos claves para el diagnóstico y manejo de esta enfermedad para el médico residente y especialista en Cirugía general.

Association of Hyperparathyroidism and Papillary Thyroid Cancer: A Multicenter Retrospective Study

BACKGROUND

Concomitant papillary thyroid cancer (PTC) and hyperparathyroidism (HPT) have been reported in several studies. Our study aimed to investigate the incidence of concomitant PTC in HPT patients upon preoperative diagnosis and present a clinical opinion on detecting thyroid malignancy in case of parathyroidectomy.

METHODS

Patients who underwent parathyroidectomy between January 2009 and December 2019 in two medical centers were included. Of the 279 participants 154 were diagnosed as primary hyperparathyroidism (pHPT) and 125 as secondary hyperparathyroidism (sHPT). The incidence of concomitant PTC and its clinical characteristics were compared with 98 patients who underwent thyroidectomy and were diagnosed with classical PTC during the same period.

RESULTS

Concurrent PTC was detected in 14 patients (9.1%) with pHPT and in nine patients (7.2%) with sHPT. Ten (71.4%) and seven (77.8%) PTCs were microcarcinomas in the pHPT and sHPT cases respectively. In the pHPT patients, vitamin D was lower in the pHPT+PTC group (13.0±3.7 ng/mL) than in the pHPT-only group (18.5±10.4 ng/mL; P=0.01). Vitamin D levels were also lower in the sHPT+PTC group (12.3±5.6 ng/mL) than in the sHPT-only group (18.0±10.2 ng/mL; P=0.12). In the concomitant PTC group, lymph node ratio was higher than in the classical PTC group (P=0.00).

CONCLUSION

A high prevalence of concomitant PTC was seen in patients with pHPT and sHPT. Those concomitant PTCs were mostly microcarcinomas and had more aggressive features, suggesting that efforts should be made to detect concomitant malignancies in the preoperative parathyroidectomy evaluation.

Radiofrequency Ablation of Parathyroid Adenomas: Safety and Efficacy in a Study of 10 Patients

PURPOSE

To evaluate safety and effectiveness of ultrasound-guided percutaneous radiofrequency ablation of parathyroid adenoma in surgically unfit patients with hypercalcemia because of hyperparathyroidism.

MATERIALS AND METHODS

A retrospective review of hospital records from Jan 2012 to Dec 2018 revealed 10 patients, who had undergone ablation for solitary parathyroid adenoma. All 10 patients suffered from hyperparathyroidism because of parathyroid adenoma, resulting in hypercalcemia. These patients were surgically unfit because of comorbidities. Pre-ablation serum calcium and serum parathormone levels were measured and compared with the levels after the ablation.

RESULTS

Mean serum calcium level decreased significantly from 2.81 ± 0.17 mmol/L pre-ablation to 2.42 ± 0.17 mmol/L 72 h after ablation and parathyroid hormone levels became normal in all patients within 7 days. Seven patients remained normo-calcaemic at 6 months follow-up with no signs and symptoms of hyperparathyroidism. One patient with pancreatitis died after 15 days because of pre-existing multi-organ failure. Two patients were lost to follow-up before 6 months.

CONCLUSION

Radiofrequency ablation of parathyroid adenoma is a safe and effective alternate treatment method for symptomatic hypercalcemia in surgically unfit patients suffering from primary hyperparathyroidism because of parathyroid adenoma.

Parathyroidectomy for patients with secondary hyperparathyroidism in a changing landscape for the management of end-stage renal disease

BACKGROUND

The landscape of patients with end-stage renal disease is changing with the increasing availability of kidney transplantation. In the near future, a less aggressive approach to treat secondary hyperparathyroidism might be beneficial. We report outcomes of parathyroidectomy for end-stage renal disease-related hyperparathyroidism comparing the outcomes of limited, subtotal, and total parathyroidectomy.

METHODS

We performed a retrospective analysis of prospectively collected data. Patients were divided into 3 parathyroidectomy subgroups: limited (<3 glands removed), subtotal (3-3.5 glands), and total (4 glands) parathyroidectomy. Primary outcome was serum levels of parathyroid hormone. Secondary endpoints were serum levels of calcium, phosphate, and alkaline phosphatase, postoperative complications, and persistent or recurrent disease rates.

RESULTS

In total, 195 patients were included for analysis of whom 13.8% underwent limited parathyroidectomy, 46.7% subtotal parathyroidectomy, and 39.5% total parathyroidectomy. Preoperative parathyroid hormone levels (pg/mL) were 471 (210-868), 1,087 (627-1,795), and 1,070 (475-1,632) for the limited, subtotal, and total parathyroidectomy groups, respectively (P < .001). A decrease in serum parathyroid hormone was seen in all groups; however, postoperative levels remained greater in the limited parathyroidectomy group compared to the subtotal and total parathyroidectomy groups (P < .001). Serum calcium, phosphate, and alkaline phosphatase levels decreased in all groups to within the reference range. In the limited parathyroidectomy group, persistent disease and recurrence occurred more frequently (P = .02 and P = .07, respectively).

CONCLUSION

Subtotal parathyroidectomy is the optimal strategy in an era with an increasing availability of kidney transplantation and improved regimens of dialysis. In this changing practice, the approach to parathyroid surgery, however, might shift to a less aggressive and patient-tailored approach.

Parathyroid Imaging

Primary hyperparathyroidism (PHPT) is a common endocrine abnormality, caused in most cases by a single parathyroid adenoma. Surgery remains the first-line curative therapy in PHPT. Imaging plays a vital role in presurgical localization of parathyroid adenomas. Ultrasound provides a safe and quick imaging modality free of ionizing radiation, but is operator dependent. Sestamibi scan offers comparable sensitivity to ultrasound, improved with concurrent tomographic imaging. 4DCT remains a problem-solving technique in challenging cases and after failed neck exploration. We present an overview of various parathyroid imaging modalities, including protocols and findings, in addition to relevant pearls and pitfalls.

Three Rare Concurrent Complications of Tertiary Hyperparathyroidism: Maxillary Brown Tumor, Uremic Leontiasis Ossea, and Hungry Bone Syndrome

A 48-year-old woman in her 40’s with end-stage renal disease and tertiary hyperparathyroidism (HPT) presented for a rapidly progressive maxillary tumor. Initial workup was notable for elevated intact parathyroid hormone (PTH) and diffuse thickening of skull and facial bones on computed tomography, and maxillary tumor biopsy with multinucleated giant cells. She underwent subtotal parathyroidectomy (with removal of a parathyroid adenoma and 2 hyperplastic glands) and partial resection of maxillary brown tumor. The patient’s post-operative course was complicated by hungry bone syndrome, with hypocalcemia refractory to aggressive calcium repletion. Teriparatide (recombinant PTH) was utilized with rapid resolution of hypocalcemia. To our knowledge, this is the first case of maxillary brown tumor in tertiary HPT to be reported in the USA. This case also supports teriparatide as a novel therapeutic for hungry bone syndrome refractory to aggressive calcium repletion.

Critical analysis of the intraoperative parathyroid hormone decrease during parathyroidectomy for secondary and tertiary hyperparathyroidism

BACKGROUND

This study aims to determine whether intraoperative parathyroid hormone monitoring helps to predict early surgical outcomes in patients with renal hyperparathyroidism and evaluate the impact on decision making during surgery.

METHODS

A prospective study was conducted. Serial samples of the intraoperative parathyroid hormone were collected; 2 of these were taken before the excision, and 2 were taken after the planned parathyroid resection (10 minutes and 15 minutes). We tested the criterion of an intraoperative parathyroid hormone percentage decay ≥80% of the highest value of the basal samples as a predictor of success.

RESULTS

Of the 228 patients, parathyroidectomy achieved success in 92.1%. In patients with secondary hyperparathyroidism, the failure group showed a tendency to stabilize or even increase the intraoperative parathyroid hormone values from the 10-minute measure (577 pg/mL) to the 15-minute measure (535 pg/mL) (P = .903). Conversely, intraoperative parathyroid hormone continued to drop in those with a successful outcome: 245 pg/mL (10 minutes) and 206 pg/mL (15 minutes) (P < .001). The failure group had a significantly lower percentage decay (P < .001) from baseline when compared with the success group. The intraoperative parathyroid hormone influenced the surgical management in up to 7% of the cases. The intraoperative parathyroid hormone dosage method showed an accuracy of 86%, a sensitivity of 88%, and specificity of 67%.

CONCLUSION

In patients with renal hyperparathyroidism undergoing parathyroidectomy, the use of intraoperative parathyroid hormone may help to predict an early therapeutic outcome with high sensitivity and accuracy by indicating the operation's success when there is an 80% reduction of baseline intraoperative parathyroid hormone 15 minutes after removal of the enlarged glands, an associated continuous decrease in serum intraoperative parathyroid hormone levels between 10 and 15 minutes, and achievement of plasma target values <500 pg/mL.

Clinical and Economical Outcomes Associated with Parathyroidectomy: A 5-Year Population-Based Study in a Middle-Income Country with Universal Health Coverage

Parathyroidectomy (PTX) is one of the most frequently performed surgeries in chronic kidney disease (CKD) patients. The objective of this study was to determine the intensive care unit (ICU) admission, mortality and hospital readmission rates within the 30-day postoperative period, and the total cost of the care episode and to determine possible prognostic factors in end-stage renal disease (ESRD) adult patients taken to PTX in the Colombian contributory health system. Methods. Retrospective cohort study of ESRD adult patients affiliated to the Colombian contributory health system, on dialysis for at least 3 months, undergoing PTX between January 1, 2012, and November 30, 2016. The clinical outcomes evaluated were rehospitalization at 30 days, hospital stay, and ICU requirement. The costs associated with the hospitalization event in which the PTX was performed from the perspective of the third payer were estimated. Results. The study included 478 patients. The mortality rate was 2.09 per 100 surgeries, the ICU admission rate was 32.64 per 100 surgeries, the 30-day hospital readmission percentage of the postoperative period was 16.74%, and the average length of hospital stay was 5.02 days. The median total costs of care for the entire procedure was USD $ 7,814.27 (p25-p75: 3,922.03-9,372.68), with significant regional differences. The geographical region was shown as a prognostic factor associated with clinical outcomes and the cost of care. Conclusions. There are large regional differences in readmission, ICU admission and mortality rates, and costs of dialysis ESRD patients undergoing PTX belonging to the Colombian contributory regime. The geographic region behaves as an independent predictor of clinical outcomes and costs.

Endoscopic parathyroidectomy using a three-port submental approach

PURPOSE

The three-port submental endoscopic approach and its variations were introduced in 2016 and have been used for thyroidectomy since. However, there has been no report of this approach being used for parathyroidectomy [1, 2]. The objective of this paper was thus to report our experience using a three-port submental approach for endoscopic parathyroidectomy in challenging cases such as tertiary parathyroidism.

METHODS

We compared the outcomes before and after endoscopic removal of the parathyroid glands using a three-port submental endoscopic approach.

RESULTS

Endoscopic subtotal parathyroidectomy was performed using submental approach in five patients with tertiary hyperparathyroidism from January 2018 to June 2019. The parathyroid hormone levels of the patients dropped significantly after undergoing subtotal parathyroidectomy (mean difference 2260 pg/ml; 95% CI 1883.74 to 2636.65), as did calcium levels (mean difference 2.84 mg/dl; 95% CI 1.90 to 3.78). No major adverse events occurred in this study.

CONCLUSIONS

Submental approach parathyroidectomy allows for visualization of all parathyroid glands. Surgical scarring was minor and was hidden under the chin. The surgical outcomes were promising, and there were no major complications.

The role of 18F-FCH PET/CT in patients with uremic hyperparathyroidism compared with 99mTc-sestaMIBI SPECT/CT and ultrasonography

BACKGROUND

The aim of this study was to evaluate the diagnostic efficacy of ¹⁸F-fluorocholine (¹⁸F-FCH) PET/CT for uremic hyperparathyroidism (uHPT) compared to ^99mTc-sestaMIBI SPECT/CT and ultrasonography (US).

METHODS

A total of 17 uHPT patients with stage 5 chronic kidney disease (CKD) were prospectively enrolled. All patients underwent US, ^99mTc-sestaMIBI SPECT/CT, and ¹⁸F-FCH within 2 months and received surgical treatment. Visual and quantitative methods were used for image analyses. Intraoperative localization and postoperative histological results of the reference standard as well as the sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of the three modalities were analyzed using Pearson's χ² tests. In addition, the diagnostic efficacy of ¹⁸F-FCH PET/CT for uHPT was evaluated. The relationships between PET parameters and laboratory parameters were assessed using the Spearman correlation coefficient.

RESULTS

A total of 63 parathyroid hyperplasia lesions were resected in 17 uHPT patients, and 53 lesions were detected using ¹⁸F-FCH PET/CT with no false-positive results. The sensitivity, specificity, accuracy, PPV, and NPV were 84.13%, 100%, 86.49%, 100%, and 52.38%, respectively. In comparison, the corresponding values for ^99mTc-sestaMIBI SPECT/CT and US were 63.49%, 90.91%, 67.57%, 97.56%, and 30.30% and 61.90%, 81.82%, 64.86%, 95.12%, and 27.27%, respectively. The volume of hyper-functioning parathyroid glands was significantly different between lesions positive in ¹⁸F-FCH PET/CT and negative in ¹⁸F-FCH PET/CT (mean volume 1.36 ± 0.55 cm³ vs. 0.83 ± 0.26 cm³; P = 0.019). US misidentified intrathyroidal parathyroid hyperplasia as thyroid nodules in three patients, while ¹⁸F-FCH PET correctly identified the anatomy. No significant associations were observed between PET parameters and laboratory parameters in uHPT.

CONCLUSION

¹⁸F-FCH PET/CT was more sensitive and accurate for uHPT than ^99mTc-sestaMIBI SPECT/CT and US, and had better preoperative diagnostic efficacy, particularly for lesions diagnosed as a thyroid nodule by US.

Disputable Issues of Etiology and Pathogenesis of Tertiary Hyperparathyroidism

Hyperparathyroidism is a clinical and laboratory syndrome characterized by high production of the chief cells of the parathyroid hormone, a calcium-phosphorus metabolism disorder and the organ failure (kidneys, bone tissue).There are primary, secondary and tertiary hyperparathyroidism.This literature review is focused on tertiary hyperparathyroidism and includes the following sections: definition of different forms of hyperparathyroidism, the role of vitamin D in the tertiary hyperparathyroidism development, the development of tertiary hyperparathyroidism in chronic kidney disease patients, the development of tertiary hyperparathyroidism in patients after kidney transplantation, differential diagnosis various forms of hyperparathyroidism, indications for surgical tertiary hyperparathyroidism treatment in patients with kidney disease, in patients with normal kidney function.Objective. The objective of this literature review is to study the current information about this definition, pathogenesis, diagnosis and treatment of tertiary hyperparathyroidism.Methodology. The literature review was taken in English data bases MEDLINE (Pubmed), Scopus, Cochlear library, using following keywords: “secondary hyperparathyroidism pathogenesis diagnosis treatment”, “tertiary hyperparathyroidism pathogenesis diagnosis treatment”, “development of tertiary hyperparathyroidism from secondary hyperparathyroidism”, “chronic vitamin D deficiency, hyperparathyroidism”, “early stages of chronic renal failure, hyperparathyroidism”. Also, search for the same keywords was completed in Russian data base Elibrary.Discussion. Both the lack of a common understanding of this problem, and the presence of diverse and contradictory data of the etiology and pathogenesis indicate the need for further study of tertiary hyperparathyroidism.

Timing of Parathyroidectomy Does Not Influence Renal Function After Kidney Transplantation

BACKGROUND

Parathyroidectomy (PTx) is the treatment of choice for end-stage renal disease (ESRD) patients with therapy-resistant hyperparathyroidism (HPT). The optimal timing of PTx for ESRD-related HPT-before or after kidney transplantation (KTx)-is subject of debate.

METHODS

Patients with ESRD-related HPT who underwent both PTx and KTx between 1994 and 2015 were included in a multicenter retrospective study in four university hospitals. Two groups were formed according to treatment sequence: PTx before KTx (PTxKTx) and PTx after KTx (KTxPTx). Primary endpoint was renal function (eGFR, CKD-EPI) between both groups at several time points post-transplantation. Correlation between the timing of PTx and KTx and the course of eGFR was assessed using generalized estimating equations (GEE).

RESULTS

The PTxKTx group consisted of 102 (55.1%) and the KTxPTx group of 83 (44.9%) patients. Recipient age, donor type, PTx type, and pre-KTx PTH levels were significantly different between groups. At 5 years after transplantation, eGFR was similar in the PTxKTx group (eGFR 44.5 ± 4.0 ml/min/1.73 m²) and KTxPTx group (40.0 ± 6.4 ml/min/1.73 m², p = 0.43). The unadjusted GEE model showed that timing of PTx was not correlated with graft function over time (mean difference -1.0 ml/min/1.73 m², 95% confidence interval -8.4 to 6.4, p = 0.79). Adjustment for potential confounders including recipient age and sex, various donor characteristics, PTx type, and PTH levels did not materially influence the results.

CONCLUSIONS

In this multicenter cohort study, timing of PTx before or after KTx does not independently impact graft function over time.

Secondary and Tertiary Hyperparathyroidism: A Narrative Review

End-stage renal disease is often complicated by the occurrence of secondary and eventually tertiary hyperparathyroidism, characterized by increased parathormone, calcium, and phosphate concentrations. Related symptoms include pruritus and osteodynia, concentration difficulties, and feelings of depression may be present. In the long-term, end-stage renal disease patients with hyperparathyroidism have an increased risk of all-cause and cardiovascular mortality. Among treatment options are vitamin D supplements, phosphate binders, calcimimetics, and surgical parathyroidectomy. Determining the optimal treatment for the individual patient is challenging for nephrologists and endocrine surgeons. This review resumes the pathogenesis of hyperparathyroidism, clinical presentation, required diagnostic work-up, and discusses indications for the available treatment options for patients with secondary and tertiary hyperparathyroidism.