Trends in parathyroidectomy rates in US hemodialysis patients from 1992 to 2007

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.

Black patients are more likely to undergo parathyroidectomy for secondary hyperparathyroidism

BACKGROUND

Prior studies have demonstrated racial disparities in the severity of secondary hyperparathyroidism among dialysis patients. Our primary objective was to study the racial and socioeconomic differences in the timing and likelihood of parathyroidectomy in patients with secondary hyperparathyroidism.

METHODS

We used the United States Renal Data System to identify 634,428 adult (age ≥18) patients who were on maintenance dialysis between 2006 and 2016 with Medicare as their primary payor. Adjusted multivariable Cox regression was performed to quantify the differences in parathyroidectomy by race.

RESULTS

Of this cohort, 27.3% (173,267) were of Black race. Compared to 15.4% of White patients, 23.1% of Black patients lived in a neighborhood that was below a predefined poverty level (P < .001). The cumulative incidence of parathyroidectomy at 10 years after dialysis initiation was 8.8% among Black patients compared to 4.3% among White patients (P < .001). On univariable analysis, Black patients were more likely to undergo parathyroidectomy (adjusted hazard ratio = 1.83; 95% confidence interval, 1.74-1.93). This association persisted after adjusting for age, sex, cause of end-stage renal disease, body mass index, comorbidities, dialysis modality, and poverty level (adjusted hazard ratio = 1.35; 95% confidence interval, 1.27-1.43). Therefore, patient characteristics and socioeconomic status explained 26% of the association between race and likelihood of parathyroidectomy.

CONCLUSION

Black patients with secondary hyperparathyroidism due to end-stage renal disease are more likely to undergo parathyroidectomy with shorter intervals between dialysis initiation and parathyroidectomy. This association is only partially explained by patient characteristics and socioeconomic factors.

Impact of parathyroidectomy among nondiabetic hemodialysis patients with severe hyperparathyroidism

Background

Parathyroidectomy (PTX) is a treatment for hyperparathyroidism (HPT) and has uncertain risks and benefits. The aim of this study was to evaluate the effect of PTX versus nonoperative treatment among nondiabetic hemodialysis patients.

Methods

A retrospective matched cohort study was performed. Each PTX patient was matched with one patient who had severe HPT but rejected PTX. The patients were matched by sex, birth date, date of first dialysis, nondiabetic status, and left ventricular ejection fraction. The serum markers, survival, main adverse cardiovascular and cerebrovascular event (MACCE) rates, and hospitalization were compared between the PTX patients and matched non-PTX patients.

Results

There were 1143 patients at our center in the Chinese National Renal Data System (CNRDS) between 2010 and 2020. Of these, 75 PTX patients were matched with 75 non-PTX patients. Rapid decreases in the mean intact parathyroid hormone, calcium and phosphorus concentrations, and a gradual increase in hemoglobin concentration were observed in the PTX group. The mortality was 2.9 per 100 patient-years in the PTX group and 10.9 per 100 patient-years in the non-PTX group (p < 0.001). Compared with non-PTX patients, PTX patients had an adjusted HR for death of 0.236 (95% CI 0.108–0.518). The cumulative MACCE rates were 6.7 per 100 patient-years in the PTX group and 15.2 per 100 patient-years in the non-PTX group (p < 0.001). The adjusted HR of the occurrence of first MACCE for PTX patients compared with non-PTX patients was 0.524 (95% CI 0.279-0.982). The cumulative hospitalization rates were 50.3 per 100 patient-years in the PTX group and 66.5 per 100 patient-years in the matched non-PTX group (p < 0.001).

Conclusions

Compared with non-PTX patients, PTX was associated with an improvement in the biochemical measures and patient-level outcomes in nondiabetic hemodialysis patients with severe HPT.

Ambulatory Parathyroidectomy for Secondary Hyperparathyroidism at a Large Dialysis Program in Toronto: A Program Report

Purpose of program:

Operative wait times for non-oncology-related procedures continue to rise in Canada, and this was further exacerbated by the COVID-19 pandemic. These challenges will remain prevalent beyond the pandemic given the limited number of acute care beds and resources required to care for patients. As a result, the need for innovative approaches to optimize the utilization of health care resources while maintaining equitable and timely access is needed. In this report, we describe the development of a collaborative ambulatory parathyroidectomy program between two centers in Toronto, allowing for more expedient surgical treatment of secondary hyperparathyroidism among patients from a large dialysis program.

Sources of information:

The need for expanded access to surgical care for secondary hyperparathyroidism was identified through interdepartmental communication between referring nephrologists and surgeons at Sunnybrook Health Sciences Centre and Women’s College Hospital, respectively.

Methods:

A multidisciplinary ambulatory parathyroidectomy planning team was formed that included nephrologists, endocrine surgeons, nurses, and patient care managers to conduct a needs assessment. It was identified that patients had long wait times, and to address that gap in care, a protocol was developed to identify suitable patients requiring treatment. The teams created a plan to coordinate patient care and transfers. A clinical tool and protocol for post-operative management of hypocalcemia was developed using a Delphi model, gathering input from many members of the care team. The Delphi process to finalize the protocol included a series of virtual meetings over a period of about 4 months with various stakeholders and included input from two departmental heads (medicine and surgery), three nephrologists, a nurse practitioner, a patient care manager, and two nurse educators. Meetings involved core members of the Nephrology Quality Improvement and Patient Safety at Sunnybrook Health Sciences Centre and finalized protocol was agreed upon by members of this group at a quarterly meeting.

Key findings:

In this article, we describe the development, initial deployment, and planned assessment of the ambulatory parathyroidectomy program at the Women’s College Hospital and Sunnybrook Health Sciences Centre. The primary aim of the program is to increase accessibility to parathyroidectomy for secondary hyperparathyroidism. A secondary aim was to allow patients to have streamlined care with a team that is well versed with maintenance dialysis needs and optimizing treatment of post operative hypocalcemia through standardized protocols.

Limitations:

Ambulatory parathyroidectomy relies on effective communication, flow, and availability of acute care beds. It is anticipated that occasionally, unexpected hospital demands, and health care disruptions may occur, which can limit efficiency of the program. We will also need to examine the cost-effectiveness of this program as it may improve access but increase costs related to the procedure. As the program is implemented, useful adaptations and policies to our protocol to help mitigate these limitations will be documented and published in our outcomes report.

Implications:

Ontario residents with chronic kidney disease with secondary hyperparathyroidism who have failed medical management will have increased and timely access to parathyroidectomy.

Increasing rates of parathyroidectomy to treat secondary hyperparathyroidism in dialysis patients with Medicare coverage

BACKGROUND

Secondary hyperparathyroidism affects nearly all patients with renal failure on dialysis. Medical treatment of secondary hyperparathyroidism has considerably evolved over the past 2 decades, with parathyroidectomy reserved for severe cases. The primary objective of our study was to understand how trends in medical treatments affected parathyroidectomy rates in patients with secondary hyperparathyroidism on dialysis.

METHODS

We used the United States Renal Data System to identify 379,835 adult patients (age ≥18) who were on maintenance dialysis in the United States between 2006 and 2016 with Medicare as the primary payor and ascertained treatment for secondary hyperparathyroidism. Adjusted rate ratios for rates of parathyroidectomy were calculated using multivariable-adjusted Poisson regression.

RESULTS

Of 379,835 secondary hyperparathyroidism patients, 4,118 (1.1%) underwent parathyroidectomy, 39,835 (10.5%) received cinacalcet, 243,522 (64.1%) received phosphate binders, 17,571 (4.6%) received vitamin D analogs, and 86,899 (22.9%) received no treatment during the 10 years of follow-up. Over the entire study period, there was a 3.5-fold increase in the use of calcimimetics and a 3.4-fold increase in rates of parathyroidectomy. Compared to 2006 through 2009, utilization of parathyroidectomy increased 52% (adjusted rate ratio = 1.52, 95% confidence interval: 1.39-1.65) between 2010 and 2013 and by 106% (adjusted rate ratio = 2.06, 95% confidence interval: 1.90-2.24) between 2014 and 2016. The greatest increase in parathyroidectomy utilization occurred in younger patients (age 18-64 years), Black patients, female patients, those living in higher poverty neighborhoods, those listed for kidney transplant, and those who live in the Southern region of the United States.

CONCLUSION

Despite the evolution of medical treatments and an increase in the use of calcimimetics to treat secondary hyperparathyroidism, parathyroidectomy rates have been steadily increasing among dialysis patients with Medicare coverage.

Does Etelcalcetide reverse myelofibrotic bone changes due to hyperparathyroidism? A case report

Secondary hyperparathyroidism (SHPT) in dialysis is common. A young man on chronic hemodialysis with SHPT developed pancytopenia with resistant anemia requiring transfusions. A bone marrow biopsy showed grade 3 fibrosis, depleted cellularity, osteosclerosis, and decreased myelopoiesis. He initiated Etelcalcetide 7⋅5 mg 3 times weekly with improvement in SHPT concomitant with near normalization of blood counts. Marrow biopsy at 12 months showed clearance of marrow reticulin, improvement of osteosclerosis and normalization of bone trabeculae, cellularity and myelopoiesis. This is a unique case in which Etelcalcetide treatment is comparable to parathyroidectomy on SHPT and is associated with significant improvement in severe myelofibrosis.

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.

Effects of Social Disparities on Management and Surgical Outcomes for Patients with Secondary Hyperparathyroidism

INTRODUCTION

Nearly 80% of chronic renal failure patients have secondary hyperparathyroidism. Cinacalcet is used to lower parathyroid hormone; however, it is expensive and has side effects. When secondary hyperparathyroidism is resistant to medication or medications are inaccessible, parathyroidectomy is performed. Race and socioeconomic status influence access to care and surgical outcomes. We sought to evaluate the effect of race and socioeconomic status on parathyroidectomy rate as well as surgical outcomes of patients with secondary hyperparathyroidism.

METHODS

We undertook cross-sectional analysis of adults diagnosed with secondary hyperparathyroidism in the USA between 2012 and 2014, using the National Inpatient Sample. Univariate and multivariate analyses were used to determine associations between social disparities, likelihood to undergo parathyroidectomy, and surgical outcomes.

RESULTS

Between 2012 and 2014, a national estimate of 724,170 hospitalizations were identified where patients had a diagnosis of secondary hyperparathyroidism. Operative rate was 0.67%. By socioeconomic status, differences in rates of surgery in the poorest compared to the richest were not significant (0.74% vs. 0.55%, OR 1.08, p = 0.5). African-American patients had higher rates of parathyroidectomy compared to Caucasians (1 vs. 0.74%, OR 1.49, p < 0.001). African-American patients also had a trend toward more complications and greater length of stay.

CONCLUSIONS

According to a large administrative dataset, parathyroidectomy for secondary hyperparathyroidism is seldom used in the USA. African-American patients have higher rates of surgical management. Surgical outcomes may be affected by race. Clinicians treating secondary hyperparathyroidism should be aware of existing disparities within their health system.

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.

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.

Long-term outcomes and management considerations after parathyroidectomy in the dialysis patient

Parathyroidectomy (PTX) remains an important intervention for dialysis patients with poorly controlled secondary hyperparathyroidism (SHPT), though there are only retrospective and observational data that show a mortality benefit to this procedure. Potential consequences that we seek to avoid after PTX include persistent or recurrent hyperparathyroidism, and parathyroid insufficiency. There is considerable subjectivity in defining and diagnosing these conditions, given that we poorly understand the optimal PTH targets (particularly post PTX) needed to maintain bone and vascular health. While lowering PTH after PTX decreases bone turnover, long-term changes in bone activity have been poorly explored. High turnover bone disease, usually present at the time a PTX is considered, often swings to a state of low turnover in the setting of sufficiently low PTH levels. It remains unclear if all low bone turnover equate with disease. However, such changes in bone turnover appear to predispose to vascular calcification, with positive calcium balance after PTX being a potential contributor. We know little of how the post-PTX state resets calcium balance, how calcium and VDRA requirements change or what kind of adjustments are needed to avoid calcium loading. The current consensus cautions against excessive reduction of PTH although there is insufficient evidence-based guidance regarding the management of chronic kidney disease - mineral bone disease (CKD-MBD) parameters in the post-PTX state. This article aims to compile existing research, provide an overview of current practice with regard to PTX and post-PTX chronic management. It highlights gaps and controversies and aims to re-orient the focus to clinically relevant contemporary priorities in CKD-MBD management after PTX.

CKD-MBD management: what is the role of parathyroidectomy? Results from a nationwide survey in Italy

We herein report on a nationwide survey conducted in Italy to investigate the use of parathyroidectomy (PTX). In spite of the availability of newer and more effective drugs to control chronic kidney disease mineral bone disorder (CKD-MBD) biochemical abnormalities, PTX still remains a resource for nephrologists to use. However, observational analyses suggest that in recent years there has been a constant decline in the number of patients undergoing PTX. The reasons are not clear, though the increasing age and number of comorbidities of dialysis patients may partly explain this trend. Poor adherence to guidelines and/or geographical as well as logistic factors may also contribute to the lower use of PTX. The working group on CKD-MBD of the Italian Society of Nephrology launched a nationwide survey to investigate clinical practice patterns for PTX in Italy and identify modifiable factors that may limit accessibility to surgery.

Managing hyperparathyroidism in hemodialysis: role of etelcalcetide

Secondary hyperparathyroidism (SHPT) is common in patients receiving maintenance hemodialysis and is associated with adverse outcomes. Currently, SHPT is managed by reducing circulating levels of phosphate with oral binders and parathyroid hormone (PTH) with vitamin D analogs and/or the calcimimetic cinacalcet. Etelcalcetide, a novel calcimimetic administered intravenously (IV) at the end of a hemodialysis treatment session, effectively reduces PTH in clinical trials when given thrice weekly. Additional clinical effects include reductions in circulating levels of phosphate and FGF-23 and an improved profile of markers of bone turnover. However, despite being administered IV, etelcalcetide appears to be associated with rates of nausea and vomiting comparable to those of cinacalcet. Additionally, etelcalcetide, relative to placebo, causes hypocalcemia and prolonged electrocardiographic QT intervals, effects that must be considered when contemplating its use. Etelcalcetide likely has a role in treating hemodialysis patients with uncontrolled SHPT or with hypercalcemia or hyperphosphatemia receiving activated vitamin D compounds. However, its use should be at least partially constrained by consideration of the risk of hypocalcemia and resultant prolonged QT intervals in vulnerable patients. Because of its effectiveness as a PTH-reducing agent administered in the dialysis unit, etelcalcetide represents a potentially promising new therapeutic approach to the often vexing problem of SHPT in hemodialysis patients. However, whether its use is associated with changes in surrogate clinical end points, such as effects on rates of parathyroidectomy, fracture, vascular calcification, or mortality or on quality of life, remains to be studied.

SURGERY OUTCOMES IN PATIENTS WITH SECONDARY HYPERPARATHYROIDISM AND IMPACT OF INTRA-OPERATIVE PTH MEASUREMENT

Context

The current therapeutical management of secondary hyperparathyroidism (S-HPTH) is difficult to obtain due to the lack of kidney donors. Surgical intervention on the pathologic parathyroid tissue has been suggested as a method to alleviate symptoms in patients with chronic kidney disease (CKD).

Objective

The aim of our study was to evaluate the outcomes of parathyroid surgery in patients with S-HPTH and the advantages of intraoperative quick PTH (iqPTH) to improve surgical results.

Material and methods

In a real-life study, we compared one group of S-HPTH with iqPTH performed after removing all suspected glands and before wound suture (Group 1) and one group in that iqPTH was not assessed (Group 2). When iqPTH dropped less than 50%, additional exploration followed.

Results

Eight out of the 34 patients from Group 1, who underwent subtotal parathyroidectomy, showed elevated levels of serum PTH and calcium, which remained elevated during follow-up, thus, suggesting disease persistence. From the 21 patients in Group 2, none showed early postoperative disease persistence. Serum calcium, but not PTH was increased in one patient from the iqPTH group but normalized after one month. Overall, iqPTH allowed detection of a supplementary parathyroid gland in one case, thereby increasing early post-surgery remission to 100% in Group 2 compared to 76.47% in Group 1. Late postoperative remission of hyperparathyroidism with no further increase in the rate of hypoparathyroidism was obtained in Group 2.

Conclusions

Assessment of intra-operative PTH levels proved to be a useful tool in augmenting the outcome of S-HPTH surgery. In patients which are eligible for renal transplantation who undergo a subtotal resection, iqPTH can enhance the post-operative quality of life by lowering disease recurrence rates until the kidney transplant procedure.

Severe hyperkalaemia complicating parathyroidectomy in patients with end-stage renal disease

We evaluated the incidence of perioperative hyperkalaemia in end-stage renal disease (ESRD) patients undergoing parathyroidectomy and investigated possible contributors to this phenomenon. This was a retrospective cohort study looking at patients who had undergone parathyroidectomy for chronic kidney disease-associated mineral bone disease (CKD-MBD) at The Alfred Hospital, Melbourne, since 2001. Baseline demographics including age, gender, aetiology of renal failure and mode of renal replacement therapy as well as anaesthetic technique and duration of surgery were studied as possible contributors. Perioperative potassium values were compared to preoperative baseline. Following stratification into normokalaemic and hyperkalaemic groups, demographic and operative data were compared. Twenty-two patients met the inclusion criteria with a median (interquartile range, IQR) age of 48.5 (42-59) years. There was a male predominance of 68%. The median (IQR) surgical time was 131 (115-164) minutes. Potassium levels rose perioperatively, with a 27.3% incidence of perioperative hyperkalaemia. Median duration of surgery was longer in the hyperkalaemic patients (167 minutes versus 125 minutes). Following the withdrawal of cinacalcet, parathyroidectomy is increasingly required in ESRD patients with CKD-MBD. Potentially life-threatening hyperkalaemia poses a significant risk in the perioperative period. Serial electrolyte monitoring is crucial to safety in this patient group. A multidisciplinary approach to perioperative management is required to ensure optimal timing of renal replacement therapy and appropriate means of serial blood sampling.

Evaluation of Parathyroidectomy for Secondary and Tertiary Hyperparathyroidism by the Parathyroid Surgeons' Society of Japan

Secondary hyperparathyroidism (SHPT) remains a serious complication in patients with chronic kidney disease, and some patients require parathyroidectomy. The Parathyroid Surgeons' Society of Japan (PSSJ) evaluated parathyroidectomy for SHPT and tertiary hyperparathyroidism (THPT) in Japan. The annual numbers of parathyroidectomies between 2004 and 2013 were evaluated using questionnaires. Since 2010, the PSSJ has registered the patients. In total, 826 patients from 42 institutions were registered. The annual number of parathyroidectomies for SHPT and THPT in Japan increased from 2004 to 2007 and then decreased markedly after 2007, with 296 operations performed in 2013. The number of women and men was almost equal (397/427). Median (interquartile range) age of these patients was 59.0 (24-87) years, the duration of hemodialysis before parathyroidectomy was 10.83 (0.0-38.7) years, and diabetic nephropathy was 87/826 (10.5%). Of these patients 59.6% were treated with cinacalcet at undergoing parathyroidectomy. In 75.3% of patients, a total parathyroidectomy with forearm autograft was performed. In 77.7% of patients, four or more parathyroid glands were removed during the initial operation. The incidences of husky voice and wound hemorrhage were 2.9% and 1.1%, respectively. The number of parathyroidectomies for SHPT in Japan decreased markedly after the introduction of cinacalcet. Based on the evaluation of registered patients, parathyroidectomies have been successfully performed at the institutions participating in the PSSJ.

Facility-level CKD-MBD composite score and risk of adverse clinical outcomes among patients on hemodialysis

BACKGROUND

Patients receiving hemodialysis with values outside of target levels for parathyroid hormone (PTH: 150-600 pg/mL), calcium (Ca: 8.4-10.2 mg/dL), and phosphate (P: 3.5-5.5 mg/dL) are at elevated morbidity and mortality risk. We examined whether patients receiving care in dialysis facilities where greater proportions of patients have at least two values out of target have a higher risk of adverse clinical outcomes.

METHODS

The study cohort consisted of 39,085 prevalent hemodialysis patients in 1298 DaVita dialysis facilities as of September 1, 2009, followed from January 1, 2010, until an outcome, a censoring event, or December 31, 2010. We determined the quintile of the distribution across facilities of the proportion of patients with at least two of three parameters out of, or above, target over a 4-month baseline period. The primary composite outcome was cardiovascular hospitalization or death. Secondary outcomes included death, cardiovascular hospitalization, and parathyroidectomy. Poisson regression models were used to estimate the association of facility quintile with outcomes.

RESULTS

Facility quintile was associated with a 7 % increased risk of cardiovascular hospitalization or death (quintile 5 versus 1, RR 1.07, 95 % CI 1.01-1.13) using the out-of-target measure of exposure and a 12 % increased risk (RR 1.12, 95 % CI 1.06-1.19) using the above-target measure. No association was seen for death using either measure. Patients in facility quintiles 3-5 (versus 1) were at increased parathyroidectomy risk (RR ranged from 2.05, 95 % CI 1.10-3.82, for quintile 3 to 2.73, 95 % CI 1.50-4.98, for quintile 5).

CONCLUSIONS

Facility level analysis of a large prevalent sample of US patients on hemodialysis demonstrates that patients in facilities with the least control of PTH, Ca, and P had the greatest risk of parathyroidectomy or the combination of cardiovascular hospitalization or death.

Hyperparathyroidism of Renal Disease

Renal hyperparathyroidism (rHPT) is a common complication of chronic kidney disease characterized by elevated parathyroid hormone levels secondary to derangements in the homeostasis of calcium, phosphate, and vitamin D. Patients with rHPT experience increased rates of cardiovascular problems and bone disease. The Kidney Disease: Improving Global Outcomes guidelines recommend that screening and management of rHPT be initiated for all patients with chronic kidney disease stage 3 (estimated glomerular filtration rate, < 60 mL/min/1.73 m(2)). Since the 1990s, improving medical management with vitamin D analogs, phosphate binders, and calcimimetic drugs has expanded the treatment options for patients with rHPT, but some patients still require a parathyroidectomy to mitigate the sequelae of this challenging disease.

Rates and Outcomes of Parathyroidectomy for Secondary Hyperparathyroidism in the United States

BACKGROUND AND OBJECTIVES

Secondary hyperparathyroidism is common among patients with ESRD. Although medical therapy for secondary hyperparathyroidism has changed dramatically over the last decade, rates of parathyroidectomy for secondary hyperparathyroidism across the United States population are unknown. We examined temporal trends in rates of parathyroidectomy, in-hospital mortality, length of hospital stay, and costs of hospitalization.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using the Healthcare Cost and Utilization Project's Nationwide Inpatient Sample, a representative national database on hospital stay regardless of age and payer in the United States, we identified parathyroidectomies for secondary hyperparathyroidism from 2002 to 2011. Data from the US Renal Data System reports were used to calculate the rate of parathyroidectomy.

RESULTS

We identified 32,971 parathyroidectomies for secondary hyperparathyroidism between 2002 and 2011. The overall rate of parathyroidectomy was approximately 5.4/1000 patients (95% confidence interval [95% CI], 5.0/1000 to 6.0/1000). The rate decreased from 2003 (7.9/1000 patients; 95% CI, 6.2/1000 to 9.6/1000), reached a nadir in 2005 (3.3/1000 patients; 95% CI, 2.6/1000 to 4.0/1000), increased again through 2006 (5.4/1000 patients; 95% CI, 4.4/1000 to 6.4/1000), and remained stable since that time. Rates of in-hospital mortality decreased from 1.7% (95% CI, 0.8% to 2.6%) in 2002 to 0.8% (95% CI, 0.1% to 1.6%) in 2011 (P for trend <0.001). In-hospital mortality rates were significantly higher in patients with heart failure (odds ratio [OR], 4.23; 95% CI, 2.59 to 6.91) and peripheral vascular disease (OR, 4.59; 95% CI, 2.75 to 7.65) and lower among patients with prior kidney transplantation (OR, 0.20; 95% CI, 0.06 to 0.65).

CONCLUSIONS

Despite the use of multiple medical therapies, rates of parathyroidectomy of secondary hyperparathyroidism have not declined in recent years.

[Management of secondary hyperparathyroidism-current impact of parathyroidectomy]

Parathyroidectomy still presents an adequate and efficient therapeutic option for the management of refractory secondary hyperparathyroidism (sHPT). Dependent on the selected surgical technique it allows the highest rate of "laboratory cure" of sHPT. The question remains as to whether these improvements translate into clinical long-term benefits regarding the sHPT-associated vascular calcification and the increased risk for cardiovascular morbidity and mortality as well as overall mortality. Recent large observational studies point in this direction but definite evidence through prospective randomized controlled trials is still lacking.

Clinical and Practical Use of Calcimimetics in Dialysis Patients With Secondary Hyperparathyroidism

CKD and CKD-related mineral and bone disorders (CKD-MBDs) are associated with high cardiovascular and mortality risks. In randomized clinical trials (RCTs), no single drug intervention has been shown to reduce the high mortality risk in dialysis patients, but several robust secondary analyses point toward important potential beneficial effects of controlling CKD-MBD-related factors and secondary hyperparathyroidism. The advent of cinacalcet, which has a unique mode of action at the calcium-sensing receptor, represented an important step forward in controlling CKD-MBD. In addition, new RCTs have conclusively shown that cinacalcet improves achievement of target levels for all of the metabolic abnormalities associated with CKD-MBD and may also attenuate the progression of vascular and valvular calcifications in dialysis patients. However, a final conclusion on the effect of cinacalcet on hard outcomes remains elusive. Tolerance of cinacalcet is limited by frequent secondary side effects such as nausea, vomiting, hypocalcemia and oversuppression of parathyroid hormone, which may cause some management difficulties, especially for those lacking experience with the drug. Against this background, this review aims to summarize the results of studies on cinacalcet, up to and including the publication of the recent ADVANCE and EVOLVE RCTs, as well as recent post hoc analyses, and to offer practical guidance on how to improve the clinical management of the most frequent adverse events associated with cinacalcet, based on both currently available information and personal experience. In addition, attention is drawn to less common secondary effects of cinacalcet treatment and advisable precautions.

The effect of parathyroidectomy on patient survival in secondary hyperparathyroidism

BACKGROUND

Secondary hyperparathyroidism is a common condition in patients with end-stage renal disease and is associated with osteoporosis and cardiovascular disease. Despite improved medical treatment, parathyroidectomy (PTX) is still necessary for many patients on renal replacement therapy. The aim of this study was to evaluate the effect of PTX on patient survival.

METHODS

A nested index-referent study was performed within the Swedish Renal Registry (SRR). Patients on maintenance dialysis and transplantation at the time of PTX were analysed separately. The PTX patients in each of these strata were matched for age, sex and underlying renal diseases with up to five referent patients who had not undergone PTX. To calculate survival time and hazard ratios, indexes and referents were assigned the calendar date (d) of the PTX of the index patient. The risk of death after PTX was calculated using crude and adjusted Cox proportional hazards regressions.

RESULTS

There were 20 056 patients in the SRR between 1991 and 2009. Of these, 579 (423 on dialysis and 156 with a renal transplant at d) incident patients with PTX were matched with 1234/892 non-PTX patients. The adjusted relative risk of death was a hazard ratio (HR) of 0.80 [95% confidence interval (CI) 0.65-0.99] for dialysis patients at d who had undergone PTX compared with matched patients who had not. Corresponding results for the patients with a renal allograft at d were an HR of 1.10 (95% CI 0.71-1.70).

CONCLUSIONS

PTX was associated with improved survival in patients on maintenance dialysis but not in patients with renal allograft.

Health state utilities associated with major clinical events in the context of secondary hyperparathyroidism and chronic kidney disease requiring dialysis

BACKGROUND

Patients with chronic kidney disease (CKD) and secondary hyperparathyroidism (SHPT) who require dialysis are at increased risk for cardiovascular events and bone fractures. To assist in economic evaluations, this study aimed to estimate the disutility of these events beyond the impact of CKD and SHPT.

METHODS

A basic one-year health state was developed describing CKD and SHPT requiring dialysis. Further health states added acute events (cardiovascular events, fractures, and surgical procedures) or chronic post-event effects. Acute health states described a year including an event, and chronic health states described a year subsequent to an event. General population participants in Canada completed time trade-off interviews from which utilities were derived. Pairwise comparisons were made between the basic state and event, and between comparable health states.

RESULTS

A total of 199 participants (54.8% female; mean age = 46.3 years) completed interviews. Each health state had ≥130 valuations. The mean (SD) utility of the basic health state was 0.60 (0.34). For acute events, mean utility differences versus the basic state were: myocardial infarction, -0.06; unstable angina, -0.05; peripheral vascular disease (PVD) with amputation, -0.33; PVD without amputation, -0.11; heart failure, -0.14; stroke, -0.30; hip fracture, -0.14; arm fracture, -0.04; parathyroidectomy, +0.02; kidney transplant, +0.06. Disutilities for chronic health states were: stable angina, -0.09; stroke, -0.27; PVD with amputation, -0.30; PVD without amputation, -0.12; heart failure, -0.14.

CONCLUSIONS

Cardiovascular events and fractures were associated with lower utility scores, suggesting a perceived decrease in quality of life beyond the impact of CKD and SHPT.

Kidney Disease Improving Global Outcomes guidelines and parathyroidectomy for renal hyperparathyroidism

BACKGROUND

Patients with end-stage renal disease develop hypocalcemia, resulting in secondary hyperparathyroidism (SHPT). No clear criterions exist to aid in surgical decision making for SHPT. The 2009 Kidney Disease Improving Global Outcomes (KDIGO) guidelines provide target ranges for serum calcium, phosphate, and parathyroid hormone (PTH) levels in patients with end-stage renal disease. Parathyroidectomy can help achieve these targets. The study purpose was to examine how parathyroidectomy for SHPT impacts KDIGO targets during immediate and long-term follow-up and to evaluate KDIGO categorization with receipt of additional surgical intervention.

METHODS

A retrospective review of a prospective parathyroidectomy database was performed. Included patients had SHPT, were on dialysis, and underwent parathyroidectomy. Calcium, phosphate, and PTH values were classified as below, within, or above KDIGO targets.

RESULTS

Between 2000 and 2013, 36 patients with SHPT met criteria. Subtotal parathyroidectomy was performed in 89%, total parathyroidectomy in 11%. Follow-up time was 54 ± 7 mo. Eight patients (22%) required additional surgery. Twenty-eight patients (76%) were alive at the last follow-up. At the last-follow up, patients had phosphate (46%), and PTH (17%) above KDIGO ranges. Factors associated with reoperation were assessed. Patient PTH within or above target immediately postoperative had a higher rate of reoperation (P < 0.01). At the last follow-up, higher phosphate (P = 0.054) and PTH (P < 0.001) were associated with higher reoperation rates, but calcium (P = 0.33) was not.

CONCLUSIONS

PTH and phosphate levels above KDIGO indices were associated with additional surgical intervention. Many patients had laboratory indices above range at the last follow up, suggesting more patients had persistent or recurrent disease than those who underwent reoperation. Patients may benefit from more aggressive medical and/or surgical management.

Clinical outcomes after parathyroidectomy in a nationwide cohort of patients on hemodialysis

BACKGROUND AND OBJECTIVES

Patients receiving dialysis undergo parathyroidectomy to improve laboratory parameters in resistant hyperparathyroidism with the assumption that clinical outcomes will also improve. However, no randomized clinical trial data demonstrate the benefits of parathyroidectomy. This study aimed to evaluate clinical outcomes up to 1 year after parathyroidectomy in a nationwide sample of patients receiving hemodialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using data from the US Renal Data System, this study identified prevalent hemodialysis patients aged ≥18 years with Medicare as primary payers who underwent parathyroidectomy from 2007 to 2009. Baseline characteristics and comorbid conditions were assessed in the year preceding parathyroidectomy; clinical events were identified in the year preceding and the year after parathyroidectomy. After parathyroidectomy, patients were censored at death, loss of Medicare coverage, kidney transplant, change in dialysis modality, or 365 days. This study estimated cause-specific event rates for both periods and rate ratios comparing event rates in the postparathyroidectomy versus preparathyroidectomy periods.

RESULTS

Of 4435 patients who underwent parathyroidectomy, 2.0% died during the parathyroidectomy hospitalization and the 30 days after discharge. During the 30 days after discharge, 23.8% of patients were rehospitalized; 29.3% of these patients required intensive care. In the year after parathyroidectomy, hospitalizations were higher by 39%, hospital days by 58%, intensive care unit admissions by 69%, and emergency room/observation visits requiring hypocalcemia treatment by 20-fold compared with the preceding year. Cause-specific hospitalizations were higher for acute myocardial infarction (rate ratio, 1.98; 95% confidence interval, 1.60 to 2.46) and dysrhythmia (rate ratio 1.4; 95% confidence interval1.16 to 1.78); fracture rates did not differ (rate ratio 0.82; 95% confidence interval 0.6 to 1.1).

CONCLUSIONS

Parathyroidectomy is associated with significant morbidity in the 30 days after hospital discharge and in the year after the procedure. Awareness of clinical events will assist in developing evidence-based risk/benefit determinations for the indication for parathyroidectomy.

Recent changes in therapeutic approaches and association with outcomes among patients with secondary hyperparathyroidism on chronic hemodialysis: the DOPPS study

BACKGROUND AND OBJECTIVES

Elevated parathyroid hormone levels may be associated with adverse clinical outcomes in patients on dialysis. After the introduction of practice guidelines suggesting higher parathyroid hormone targets than those previously recommended, changes in parathyroid hormone levels and treatment regimens over time have not been well documented.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using data from the international Dialysis Outcomes and Practice Patterns Study, trends in parathyroid hormone levels and secondary hyperparathyroidism therapies over the past 15 years and the associations between parathyroid hormone and clinical outcomes are reported; 35,655 participants from the Dialysis Outcomes and Practice Patterns Study phases 1-4 (1996-2011) were included.

RESULTS

Median parathyroid hormone increased from phase 1 to phase 4 in all regions except for Japan, where it remained stable. Prescriptions of intravenous vitamin D analogs and cinacalcet increased and parathyroidectomy rates decreased in all regions over time. Compared with 150-300 pg/ml, in adjusted models, all-cause mortality risk was higher for parathyroid hormone=301-450 (hazard ratio, 1.09; 95% confidence interval, 1.01 to 1.18) and >600 pg/ml (hazard ratio, 1.23; 95% confidence interval, 1.12 to 1.34). Parathyroid hormone >600 pg/ml was also associated with higher risk of cardiovascular mortality as well as all-cause and cardiovascular hospitalizations. In a subgroup analysis of 5387 patients not receiving vitamin D analogs or cinacalcet and with no prior parathyroidectomy, very low parathyroid hormone (<50 pg/ml) was associated with mortality (hazard ratio, 1.25; 95% confidence interval, 1.04 to 1.51).

CONCLUSIONS

In a large international sample of patients on hemodialysis, parathyroid hormone levels increased in most countries, and secondary hyperparathyroidism treatments changed over time. Very low and very high parathyroid hormone levels were associated with adverse outcomes. In the absence of definitive evidence in support of a specific parathyroid hormone target, there is an urgent need for additional research to inform clinical practice.

Role of surgery in the treatment of renal secondary hyperparathyroidism

Surgery is cost-effective

Temporal trends and risk factors for parathyroidectomy in the Swedish dialysis and transplant population - a nationwide, population-based study 1991 - 2009

BACKGROUND

Many patients on renal replacement therapy (RRT) require parathyroidectomy (PTX). Trends and current rates of PTX on a national level are not known. Furthermore, it is not completely clear which factors influence rates of PTX. Thus, our aim was to investigate the incidence, regional distribution and factors associated with PTX as well as possible temporal changes, in the Swedish RRT population.

METHODS

From the Swedish Renal Registry we extracted data on 20 015 patients on RRT between 1991 and 2009. In these, 679 incident PTX (3.4%) were identified by linkage with the National Inpatient Registry, and the Scandinavian Quality Registry for Thyroid Parathyroid and Adrenal Surgery. Poisson models were used to estimate rates per calendar year, adjusted for risk factors such as gender, age, time with renal transplant, and underlying cause of renal disease.

RESULTS

The PTX rate was 8.8/1 000 person-years. There was a significant increase 2001-2004 after which the rate fell, as compared with year 2000. Female gender, non-diabetic cause of renal disease and age between 40-55 were all associated with an increased frequency of PTX.

CONCLUSION

The rise in PTX rates after year 2000 might reflect increasing awareness of the potential benefits of PTX. The introduction of calcimimetics and paricalcitol might explain the decreased rate after 2005.

Parathyroidectomy improves symptomatology and quality of life in patients with secondary hyperparathyroidism

BACKGROUND

The parathyroidectomy assessment of symptoms (PAS) score was designed initially for primary hyperparathyroidism to provide a specific symptom assessment and was validated later in secondary and tertiary hyperparathyroidism. The aim of our study was to evaluate changes in the PAS scores and quality of life before and after parathyroidectomy for secondary hyperparathyroidism.

METHODS

This prospective study included 49 consecutive patients who underwent parathyroidectomy for secondary hyperparathyroidism. The PAS and Short Form (SF)-36 questionnaires were completed before parathyroidectomy and at 12 months postoperatively.

RESULTS

All 13 symptoms included in the PAS score improved significantly. The mean ± standard deviation PAS score decreased from 545 ± 263 to 284 ± 201 (P < .0001) after parathyroidectomy. Quality of life was enhanced in both physical (40.3 ± 17.1 to 59.0 ± 14.9; P < .0001) and mental (47.6 ± 17.1 to 63.7 ± 13.0; P < .0001) components. The PAS score was inversely correlated with the SF-36 global score preoperatively and postoperatively (r(2) = 0.48 and 0.25; P < .001). The change in PAS score also correlated with the change in SF-36 global score (r(2) = 0.29; P < .001). Multiple linear regression analysis showed that preoperative PAS score and bone mineral density T-score were predictors of the decrease in PAS score. Preoperative SF-36 global score and intact parathyroid hormone levels were predictors of the increment in SF-36 score.

CONCLUSION

The symptom burden of secondary hyperparathyroidism has a negative impact on a patient's quality of life. Parathyroidectomy is associated with a marked improvement in symptoms and quality of life.

Healthcare use and costs before and after parathyroidectomy in patients on dialysis

BACKGROUND

Parathyroidectomy (PTX) is often performed in dialysis patients when medical treatment fails to control secondary hyperparathyroidism (SHPT). PTX is viewed by many as a cost-containing measure for patients who have been treated with vitamin D analogs and calcimimetics. Yet, information about health resource utilization and costs before and after PTX is limited.

METHODS

This retrospective cohort study used professional service and pharmacy claims to identify subjects on dialysis undergoing PTX from 1/1/2008-12/31/2010. Only subjects with at least six months of information before and after PTX were considered. Subjects with primary hyperparathyroidism or kidney transplant were excluded. Prescription use, physician encounters, and surgical complications were compared during the six months immediately before and after PTX.

RESULTS

The mean (SD) age of the 181 study subjects was 51 (15) years; 59% female; and 80% insured by Medicare. Overall, the percentage of patients receiving medications to manage altered mineral metabolism increased from 67% before to 79% after PTX. Specifically, oral vitamin D use increased, while the utilization of cinacalcet decreased resulting in mean (SD) monthly medication charges decreasing from $486 (507) to $226 (288) (p < 0.01). The mean (SD) number of physician encounters rose from 15 (14) before to 21 (22) per 6 months after PTX (p < 0.01) resulting in the corresponding increase in mean (SD) monthly charges from $1531 (2150) to $1965 (3317) (p = 0.08). Hypocalcemia was the predominant diagnosis recorded for post-surgical physician encounters occurring in 31% of all subjects; 84% of hypocalcemic episodes were managed in acute care facilities.

CONCLUSIONS

The cost of medications to manage SHPT decreased after PTX largely due to reduction in cinacalcet use, whereas vitamin D use increased likely to manage hypocalcemia. The frequency and cost of physician encounters, especially in acute care settings, were higher in the 6 months after PTX attributable largely to episodes of severe hypocalcemia. Overall, the reduction in prescription costs during the 6 months after PTX is outweighed by the higher costs associated with physician care.

Temporal trends in the incidence, treatment, and outcomes of hip fracture in older patients initiating dialysis in the United States

BACKGROUND AND OBJECTIVES

Patients with ESRD experience a fivefold higher incidence of hip fracture than the age- and sex-matched general population. Despite multiple changes in the treatment of CKD mineral bone disorder, little is known about long-term trends in hip fracture incidence, treatment patterns, and outcomes in patients on dialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Fourteen annual cohorts (1996-2009) of older patients (≥67 years) initiating dialysis in the United States were studied. Eligible patients had Medicare fee-for-service coverage for ≥2 years before dialysis initiation and were followed for ≤3 years for a first hip fracture. Type of treatment (internal fixation or partial or total hip replacement) was ascertained along with 30-day mortality. Cox and modified Poisson regressions were used to describe trends in study outcomes.

RESULTS

This study followed 409,040 patients over 607,059 person-years, during which time 17,887 hip fracture events were recorded (29.3 events/1000 person-years). Compared with patients incident for ESRD in 1996, adjusted hip fracture rates increased until the 2004 cohort (+41%) and declined thereafter. Surgical treatment included internal fixation in 56%, partial hip replacement in 29%, and total hip replacement in 2%, which remained essentially unchanged over time; 30-day mortality after hip fracture declined from 20% (1996) to 16% (2009).

CONCLUSIONS

Hip fracture incidence rates remain higher today than in patients reaching ESRD in 1996, despite multiple purported improvements in the management of CKD mineral bone disorder. Although recent declines in incidence and steady declines in associated short-term mortality are encouraging, hip fractures remain among the most common and consequential noncardiovascular complications of ESRD.

Effect of cinacalcet availability and formulary listing on parathyroidectomy rate trends

Background

Recent trends in parathyroidectomy rates are not known. Our objective was to investigate the trend in parathyroidectomy rates between 2001 and 2010, and to evaluate if the availability and reimbursement of cinacalcet modified that trend.

Methods

Using a provincial administrative database, we included all adult patients receiving chronic dialysis treatments between 2001 and 2010 (incident and prevalent) in a time series analysis. The effect of cinacalcet availability on parathyroidectomy bimonthly rates was modeled using an ARIMA intervention model using different cut-off dates: September 2004 (Health Canada cinacalcet approval), January 2005, June 2005, January 2006, June 2006 (date of cinacalcet provincial reimbursement), and January 2007.

Results

A total of 12 795 chronic dialysis patients (mean age 64 years, 39% female, 82% hemodialysis) were followed for a mean follow-up of 3.3 years. During follow-up, 267 parathyroidectomies were identified, translating to an average rate of 7.0 per 1000 person-years. The average parathyroidectomy rate before cinacalcet availability was 11.4 /1000 person-years, and 3.6 /1000 person-years after cinacalcet public formulary listing. Only January 2006 as an intervention date in the ARIMA model was associated with a change in parathyroidectomy rates (estimate: -5.58, p = 0.03). Other intervention dates were not associated with lower parathyroidectomy rates.

Conclusions

A reduction in rates of parathyroidectomy was found after January 2006, corresponding to cinacalcet availability. However, decreased rates may be due to other factors occurring simultaneously with cinacalcet introduction and further studies are needed to confirm these findings.

Parathyroidectomy leads to decreased blood lead levels in patients with refractory secondary hyperparathyroidism

OBJECTIVE

Secondary hyperparathyroidism (SHPT) is characterized by high bone turnover and may result in increased release of lead (Pb) from bone stores. Parathyroidectomy (PTX) drastically changes bone remodeling. This study investigated the effects of PTX on the levels of blood lead (blood Pb) in patients with refractory SHPT.

METHODS

The study included 30 patients on long-term hemodialysis (HD) who underwent PTX in the nephrology units of two Taiwanese hospitals. Changes in serum levels of intact parathyroid hormone (iPTH), bone-specific alkaline phosphatase (BAP), type 5b tartrate-resistant acid phosphatase (TRAP), total calcium (tCa), and blood Pb were analyzed.

RESULTS

After PTX, serum iPTH was markedly decreased while serum BAP was progressively increased and peaked 2weeks after PTX. Serum TRAP levels were progressively decreased during the 4week follow-up period. Serum tCa and blood Pb levels decreased sharply immediately after PTX. There was a positive correlation between the percentage of decrease in tCa and blood Pb at one day after PTX. Further analysis indicated a significant positive correlation between levels of blood Pb and serum iPTH (r=0.378, p<0.001), blood Pb and serum TRAP (r=0.180, p<0.05), and a negative correlation between blood Pb and serum BAP (r=-0.205, p<0.05).

CONCLUSION

PTX effectively suppressed the elevated levels of blood Pb and serum bone remodeling markers, which are common features of SHPT. In addition to decreased Pb release from bone, an increased store of Pb in bone may play a role in decreasing serum blood Pb levels. These findings suggest that patients undergoing PTX for refractory SHPT should strictly avoid environmental exposure to Pb.

Life-Threatening Hypocalcemia following Subtotal Parathyroidectomy in a Patient with Renal Failure and Previous Roux-en-Y Gastric Bypass Surgery

Background. Roux-en-Y gastric bypass (RYGB) can result in calcium and vitamin D deficiency. Parathyroid surgery carries the risk of immediate and long-term hypocalcemia. Methods and Results. We describe a 54-year-old woman with history of end-stage renal disease and gastric bypass surgery who developed calciphylaxis requiring a 3.5-gland parathyroidectomy. Seven weeks later, she presented with weakness, perioral numbness, leg cramps, a positive Chvostek's sign, hypotension, prolonged QT-interval, and serum calcium of 5.4 mg/dL. Oral and intravenous calcium, calcitriol, and high calcium bath hemodialysis were given. She required 18 days of intravenous calcium and an outpatient maintenance regimen of calcitriol 6 mcg/day, calcium carbonate 8 grams/day, calcium citrate 1.2 grams/day, and ergocalciferol 50,000 IU/week. Conclusion. The patient's life-threatening prolonged hypocalcemia and large requirements of calcium and calcitriol were due to a combination of malabsorption, hypoparathyroidism, and renal failure. Special considerations should be given to bariatric surgery patients undergoing neck exploration.