Parathyroidectomy can improve bone mineral density in patients with symptomatic secondary hyperparathyroidism

Pretransplant Parathyroidectomy in Patients with Severe Secondary Hyperparathyroidism and Long-Term Effectiveness After Kidney Transplantation

Kidney transplantation (KT) is the best option for patients with end-stage renal disease, but recipients still have legacy bone mineral disease from the pretransplant period, especially patients with severe secondary hyperparathyroidism (sHPT). Patients who had severe sHPT and underwent KT were analyzed retrospectively. Two groups were identified (patients with severe sHPT who had parathyroidectomy or calcimimetic before KT). Bone mineral density (BMD) was measured in the first year and last follow-up at the femoral neck, total hip, and lumbar spine using the dual-energy X-ray absorptiometry (DXA). Persistent hyperparathyroidism (perHPT) incidence was significantly higher in the calcimimetic group (75% vs. 40%, p=0.007). In patients with parathyroidectomy, BMDs were higher at femoral neck (0.818±0.114 vs. 0.744±0.134, p=0.04) and lumbar spine (1.005±0.170 vs. 0.897±0.151, p=0.01) at the first assessment. The BMD comparison between patients treated with parathyroidectomy and calcimimetic found a significant difference only in the femoral neck at second evaluation (0.835±0.118 vs. 0.758±0.129; p=0.03). In multivariate, linear regression revealed a positive association between the last BMD of the femoral neck with body mass index (CC: 0.297, 95% CI, 0.002-0.017) and parathyroidectomy (CC: 0.319, 95% CI, 0.021-0.156). Parathyroidectomy is associated with a significantly better femoral neck BMD and a lower incidence of perHPT in patients with severe sHPT.

Does race impact outcomes after parathyroidectomy for secondary and tertiary hyperparathyroidism?

BACKGROUND

Racial disparities in care exist for diseases with heterogeneous treatment guidelines. The impact of these disparities on outcomes after parathyroidectomy for secondary(2HPT) and tertiary hyperparathyroidism(3HPT) was explored.

METHODS

The 2015-2019 NSQIP datasets were used. Patients who underwent parathyroidectomy for 2HPT and 3HPT were identified and analyzed separately. Patients were stratified by race (white vs. non-white); demographics, comorbidities, and outcomes were compared. Studied outcomes included 30-day morbidity, mortality, unplanned reoperation, readmission, and postoperative length of stay(LOS).

RESULTS

There were 1,150 patients with 2HPT and 262 with 3HPT. For 2HPT, 65.5% were non-white; morbidity, reoperation, and prolonged LOS(>3days) occurred disproportionately more often in non-white patients. Non-white race was independently associated with morbidity; higher ASA class and alkaline phosphatase levels were associated with prolonged LOS. For 3HPT, 53.1% were non-white; a prolonged LOS(>1day) occurred disproportionately more often in non-white patients. Higher alkaline phosphatase levels were independently associated with prolonged LOS.

CONCLUSION

Race and markers of advanced disease negatively impact outcomes after parathyroidectomy for 2HPT and 3HPT. Attention to racial disparities and earlier referral may positively impact outcomes.

Treatment for secondary hyperparathyroidism focusing on parathyroidectomy

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

Parathyroidectomy for dialysis patients in the era of calcimimetics: The surgeons' point of view

Calcimimetics is a new drug for lowering serum parathyroid hormone (PTH), calcium and phosphate in patients with hyperparathyroidism (HPT) on long-term dialysis. It became available on market in 2006. The impact of calcimimetics on the treatment by parathyroidectomy (PTx) was reviewed from the surgeons' point of view. Cure of renal HPT by calcimimetics is not feasible, but calcimimetics can improve preoperative cardiac ventricle ejection fractions by lowering serum PTH. Heart failure is not necessarily a contraindication for PTx. PTx should be done before irreversible organ damage occurs. Limb gangrenes is an ominous sign and should be prevented by frequent checkup for peripheral arterial circulation. The impact of renal osteodystrophy on the quality of life and as indirect cause of mortality deserves more attention in patients with renal HPT. Delayed referral to PTx leads to more complicated patients. A consensus between nephrologists and surgeons about propitious timing for PTx is necessary. Future prospect on the surgical treatment of renal HPT is proposed. Supplemental figure; http://links.lww.com/ASAIO/A782.

Predictors of Bone Mineral Density Improvement after Parathyroidectomy for Secondary Hyperparathyroidism: A Retrospective Single-Center Analysis

Background

Parathyroidectomy (PTx) reportedly increases bone mineral density (BMD) in patients with severe secondary hyperparathyroidism (SHPT). To date, however, there has not been sufficient evidence on predictors of BMD improvement post-PTx for SHPT, an issue the present retrospective cohort study aimed to address.

Methods

A total of 173 SHPT patients who underwent total PTx with forearm autograft between 2009 and 2017 were included in the present study. Demographic information, perioperative laboratory data and pre- and post-PTx BMD values (measured by dual-energy X-ray absorptiometry) were collected from their medical records. The change in BMD post-PTx in the lumbar spine was evaluated as the primary outcome. Then, a multivariate logistic regression analysis was performed for a ≥ 10% increase in BMD post-PTx.

Results

Overall, the median BMD in the lumbar spine was increased by 8.7% post-PTx. The multivariate logistic regression analysis revealed that age ≥ 70 years (P = 0.005; odds ratio [OR], 0.138; 95% confidence interval [CI]: 0.034–0.555), serum Ca level (P = 0.017; OR, 0.598; 95% CI: 0.392–0.911) and pre-PTx BMD in the lumbar spine (P = 0.003; OR, 0.013; 95% CI: 0.001–0.229) were negatively associated with a ≥ 10% increase in BMD post-PTx.

Conclusion

Our study demonstrated that presurgical age, serum Ca levels and BMD values could better predict an improvement in BMD post-PTx in SHPT patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00268-021-06186-1.

Old and New Drugs for the Management of Bone Disorders in CKD

Disturbances in mineral and bone metabolism are common in patients with chronic kidney disease (CKD), especially those undergoing dialysis. Renal osteodystrophy, which describes an alteration of bone morphology, is an important component of this systemic disorder and may explain the elevated risk of fracture which adversely affects morbidity and mortality. The most common form of renal osteodystrophy is high-turnover bone disease (osteitis fibrosa), which is induced by secondary hyperparathyroidism (SHPT). During the past decade, there has been considerable advances in the management of SHPT, with the introduction of the calcimimetic agents, the optimized use of nutritional and active vitamin D, and the accumulated experience with surgical parathyroidectomy. Studies supported that these advances could translate into improvement of renal bone disease and fracture prevention, as well as decreasing the risk of cardiovascular events and mortality. In this review, we summarize the available clinical evidence on the effect of old and new drugs on bone disorders in patients with CKD.

Surgical Management of Secondary Hyperparathyroidism

Secondary hyperparathyroidism (SHPT) affects a majority of patients with chronic kidney disease (CKD) of stage 3 or worse. Despite the development of calcimimetics and their effectiveness in treating SHPT, many patients continue to fail medical management and should be referred to a parathyroid surgeon. In this narrative review, we summarize the indications for surgical referral, preoperative planning, intraoperative strategies to guide resection, and postoperative management. In the absence of universal guidelines, it can be difficult to determine when it is appropriate to make this referral. The majority of studies evaluating parathyroidectomy (PTX) for SHPT use the criteria of parathyroid hormone level (PTH) >800 pg/ml with hypercalcemia and/or hyperphosphatemia, which may be accompanied by symptoms such as bone pain and pruritis that can improve after surgery. Although the reported utility of the various imaging modalities (i.e., 99m-technetium-sestamibi scintigraphy with computed tomography [SPECT/CT], CT, or ultrasound) is highly variable in SHPT, SPECT/CT appears to be the most sensitive. Intraoperatively, PTH monitoring is effective in predicting long-term cure of SHPT but not in predicting hypoparathyroidism. Ectopic and supernumerary parathyroid glands are common in these patients and are often implicated in persistent or recurrent disease. Postoperatively, patients are at risk of severe hypocalcemia and hungry bone syndrome requiring close monitoring and replenishment.

Control of phosphorus and prevention of fractures in the kidney patient

Patients with chronic kidney disease have a higher risk of fractures than the general population due to the added factor of uraemia. Although the mechanisms behind uraemia-associated fractures are not fully understood, it is widely accepted that the decrease in bone mineral content and alteration in bone architecture both increase bone fragility. As chronic kidney disease progresses, the risk of fracture increases, especially once the patient requires dialysis. Among the many causes of the increased risk are advanced age, amenorrhoea, steroid exposure, decreased vitamin D, increased PTH, malnutrition and chronic inflammation. Serum phosphorus, whether high or very low, seems to correlate with the risk of fracture. Moreover, increased serum phosphate is known to directly and indirectly affect bone metabolism through the development of adaptive hormonal mechanisms aimed at preventing hyperphosphataemia, such as the increase in PTH and FGF23 and the reduction in calcitriol. These adaptive mechanisms are less intense if the intestinal absorption of phosphorus is reduced with the use of phosphorus captors, which seem to have a positive impact in reducing the risk of fractures. We describe here the possible mechanisms associating serum phosphorus levels, the adaptive mechanisms typical in kidney disease and the use of drugs to control hyperphosphataemia with the risk of fractures. We found no studies in the literature providing evidence on the influence of different treatments on the risk of fractures in patients with chronic kidney disease. We suggest that control of phosphorus should be an objective to consider.

Changes to bone mineral density, the trabecular bone score and hip structural analysis following parathyroidectomy: a case report

BACKGROUND

Reduction in bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) occurs in secondary hyperparathyroidism associated with chronic kidney disease. BMD generally increases following parathyroidectomy, however longitudinal changes to other DXA-derived parameters, the trabecular bone score (TBS) and hip structural analysis (HSA), have not been described. Postoperative calcium requirements and positive calcium balance raise concerns for an increased risk of vascular calcification. This case illustrates the dramatic increase in BMD that can follow parathyroidectomy in a patient on dialysis, and for the first time demonstrates improvements to HSA parameters and to the TBS.

CASE PRESENTATION

A 30-year old woman on haemodialysis underwent subtotal parathyroidectomy for secondary hyperparathyroidism. She developed a post-operative 'hungry bone syndrome' requiring substantial calcium and calcitriol supplementation. Six months post-parathyroidectomy, BMD increased by 42% at the lumbar spine, 30% at the femoral neck and 25% at the total proximal femur, with increases sustained over the following 18 months. The TBS increased by 8%. HSA showed a 63% increase in femoral neck cortical thickness and 38% reduction in the buckling ratio, consistent with increased femoral neck stability. The abdominal aortic vascular calcification score (0-24) increased from zero 8-years pre-parathyroidectomy to 2/24 at 18-months post-parathyroidectomy.

CONCLUSION

BMD losses incurred by secondary hyperparathyroidism recover rapidly after parathyroidectomy, particularly at sites of trabecular bone. Bone architectural parameters, measured as the TBS and by HSA, also improve. Greater BMD gains may be associated with higher post-operative calcium requirements. While bone is the major reservoir for post-parathyroidectomy calcium supplementation, positive calcium balance may contribute to vascular calcification risk.

Control of phosphorus and prevention of fractures in the kidney patient

Patients with chronic kidney disease have a higher risk of fractures than the general population due to the added factor of uraemia. Although the mechanisms behind uraemia-associated fractures are not fully understood, it is widely accepted that the decrease in bone mineral content and alteration in bone architecture both increase bone fragility. As chronic kidney disease progresses, the risk of fracture increases, especially once the patient requires dialysis. Among the many causes of the increased risk are advanced age, amenorrhoea, steroid exposure, decreased vitamin D, increased parathyroid hormone (PTH), malnutrition and chronic inflammation. Serum phosphorus, whether high or very low, seems to correlate with the risk of fracture. Moreover, increased serum phosphate is known to directly and indirectly affect bone metabolism through the development of adaptive hormonal mechanisms aimed at preventing hyperphosphataemia, such as the increase in PTH and fibroblast growth factor 23 (FGF23) and the reduction in calcitriol. These adaptive mechanisms are less intense if the intestinal absorption of phosphorus is reduced with the use of phosphorus captors, which seem to have a positive impact in reducing the risk of fractures. We describe here the possible mechanisms associating serum phosphorus levels, the adaptive mechanisms typical in kidney disease and the use of drugs to control hyperphosphataemia with the risk of fractures. We found no studies in the literature providing evidence on the influence of different treatments on the risk of fractures in patients with chronic kidney disease. We suggest that control of phosphorus should be an objective to consider.

Bipolar Hemiarthroplasty and Parathyroidectomy at the Same Setting for Fragility Fractures Secondary to Renal Bone Disease

BACKGROUND

From 1980s to the new millennium, the number of patients surviving with end stage renal disease (ESRD) has increased by 3 fold. This is driven by early detection of primordial and primary risk factors, state of the art renal replacement therapy and ease of public access to healthcare. Renal osteodystrophy (RO) is a metabolic bone disease causing significant morbidity in patients with ESRD, in particular fragility fractures. In this case series, we present the surgical management of 3 ESRD patients with pathological fractures of the neck of femur (NOF) and surgical treatment (parathyroidectomy) of tertiary hyperparathyroidism of ESRD patients in the same surgical setting. Up to date there has been no reports on bipolar hemiarthroplasty and total parathyroidectomy implemented in the same operative setting.

METHODS

We present 3 cases, 2 males and a female with an average age of 48 years. All patients presented with no trauma or minimal trauma. With high index of suspicion and after confirming the diagnosis with advanced imaging, the patients underwent cemented modular hemiarthroplasty with posterior approach. Parathyroidectomy was sequentially performed to address the tertiary hyperparathyroidism at the same setting. We followed them for 48 months.

RESULTS

At 48-month follow up, all the patients were at their pre-morbid ambulatory status and there were no major complications. They did not need any revision surgery or re-operation either for the hemiarthroplasty surgery or the parathyroidectomy during the follow up period.

CONCLUSION

To avoid diagnostic pitfalls in this group of patients we recommend MRIs of both hips in patients complaining of unilateral hip pain even when the roentgenograms are clear of fractures. Total parathyroidectomy at the same setting with the bipolar hemi-arthroplasty is a safe combination. This reduces the anaesthesia risk, the recovery time as well as the equilibrium time for calcium homeostasis.

Canadian Society of Nephrology Commentary on the Kidney Disease Improving Global Outcomes 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder

Purpose of review:

(1) To provide commentary on the 2017 update to the Kidney Disease Improving Global Outcomes (KDIGO) 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD); (2) to apply the evidence-based guideline update for implementation within the Canadian health care system; (3) to provide comment on the care of children with chronic kidney disease (CKD); and (4) to identify research priorities for Canadian patients.

Sources of information:

The KDIGO 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of CKD-MBD.

Methods:

The commentary committee co-chairs selected potential members based on their knowledge of the Canadian kidney community, aiming for wide representation from relevant disciplines, academic and community centers, and different geographical regions.

Key findings:

We agreed with many of the recommendations in the clinical practice guideline on the diagnosis, evaluation, prevention, and treatment of CKD-MBD. However, based on the uncommon occurrence of abnormalities in calcium and phosphate and the low likelihood of severe abnormalities in parathyroid hormone (PTH), we recommend against screening and monitoring levels of calcium, phosphate, PTH, and alkaline phosphatase in adults with CKD G3. We suggest and recommend monitoring these parameters in adults with CKD G4 and G5, respectively. In children, we agree that monitoring for CKD-MBD should begin in CKD G2, but we suggest measuring ionized calcium, rather than total calcium or calcium adjusted for albumin. With regard to vitamin D, we suggest against routine screening for vitamin D deficiency in adults with CKD G3-G5 and G1T-G5T and suggest following population health recommendations for adequate vitamin D intake. We recommend that the measurement and management of bone mineral density (BMD) be according to general population guidelines in CKD G3 and G3T, but we suggest against routine BMD testing in CKD G4-G5, CKD G4T-5T, and in children with CKD. Based on insufficient data, we also recommend against routine bone biopsy in clinical practice for adults with CKD or CKD-T, or in children with CKD, although we consider it an important research tool.

Limitations:

The committee relied on the evidence summaries produced by KDIGO. The CSN committee did not replicate or update the systematic reviews.

Impact of denosumab on cardiovascular calcification in patients with secondary hyperparathyroidism undergoing dialysis: a pilot study

The receptor activator of nuclear factor-kappa B ligand (RANKL)/RANK/osteoprotegerin system is dysregulated in hyperparathyroid bone diseases. The introduction of denosumab preceding elective surgery as an alternative option when surgery is not possible immediately.

INTRODUCTION

The effects of denosumab on vascular calcification in patients with chronic renal failure and low bone mass have been a subject of interest. Therefore, this investigation aimed to determine the short-term changes in vascular calcification after denosumab treatment using a serial electrocardiography-gated computed tomography (CT) to measure coronary artery calcification (CAC) in patients with secondary hyperparathyroidism (SHPT) and low bone mass.

METHODS

This 6-month study enrolled patients with SHPT and low bone mass (T-score < - 2.5) owing to dialysis. The 2 groups administered denosumab at a dose of 60 mg (denosumab group), and conventional treatment (control group) had 21 patients each. All patients underwent CT scans at baseline and at the follow-up examination at 6 months to determine the bone mineral density and CAC.

RESULTS

The control group demonstrated a significant increase in Agatston scores (187.79 ± 72.27) (P = 0.004). However, no significant change was noted in the denosumab group (P = 0.41). In the denosumab group, only the baseline serum alkaline phosphatase levels correlated negatively with changes in the CAC score (P = 0.01); the baseline alkaline phosphatase levels were the deciding biomarkers for non-responsive CAC scores by Berry Criteria after denosumab treatment (P = 0.02). The denosumab group demonstrated significantly increased bone mineral density in the femoral neck and lumbar spine (P < 0.01).

CONCLUSION

The findings provide evidence that denosumab may suppress the progression of CAC and also regress osseous calcification in severe cases of high bone turnover.

Parathyroid Hormone: A Uremic Toxin

Parathyroid hormone (PTH) has an important role in the maintenance of serum calcium levels. It activates renal 1α-hydroxylase and increases the synthesis of the active form of vitamin D (1,25[OH]₂D₃). PTH promotes calcium release from the bone and enhances tubular calcium resorption through direct action on these sites. Hallmarks of secondary hyperparathyroidism associated with chronic kidney disease (CKD) include increase in serum fibroblast growth factor 23 (FGF-23), reduction in renal 1,25[OH]₂D₃ production with a decline in its serum levels, decrease in intestinal calcium absorption, and, at later stages, hyperphosphatemia and high levels of PTH. In this paper, we aim to critically discuss severe CKD-related hyperparathyroidism, in which PTH, through calcium-dependent and -independent mechanisms, leads to harmful effects and manifestations of the uremic syndrome, such as bone loss, skin and soft tissue calcification, cardiomyopathy, immunodeficiency, impairment of erythropoiesis, increase of energy expenditure, and muscle weakness.

Efficacy analysis of medical and surgical treatments in chronic kidney disease patients with secondary hyperparathyroidism

PURPOSE

To investigate the effects of surgical and medical treatments on chronic kidney disease (CKD) patients with secondary hyperparathyroidism (SHPT).

MATERIALS AND METHODS

A total of 198 CKD patients with SHPT were identified at Tongji Hospital from January 2013 to June 2017.

RESULTS

Surgical group (53 patients) received maintenance dialysis for 78.0 ± 4.9 months, while medical group (84 patients) for 62.0 ± 6.4 months. The serum intact parathyroid hormone (iPTH) in surgical group reduced apparently compared with medical group (P = 0.015) and maintained satisfied result during three years of follow-up (67.4 ± 7.4 pg/ml). The recurrence rate in surgical group was 7.5% and in medical group was 15.5% (P = 0.024). Beyond that, 5 (5.9%) patients suffered persistent hyperparathyroidism in medical group.

CONCLUSION

Although the progress of medical treatment is changing rapidly, surgical treatment is still an effective way to control serum iPTH and calcium chronically for SHPT patients. Complex SHPT patients can also receive satisfied effect by surgical treatment, without apparently increasing the risk of complications.

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.

Subtotal Parathyroidectomy vs Total Parathyroidectomy with Autotransplantation for Secondary Hyperparathyroidism in Dialysis Patients: Short- and Long-Term Outcomes

BACKGROUND

Two operations are performed for management of secondary hyperparathyroidism, subtotal parathyroidectomy (SPTX) and total parathyroidectomy with autotransplantation (TPTX-AT). There is no consensus among endocrine surgeons about which operation is the preferred treatment. This study compares the short- and long-term outcomes of SPTX and TPTX-AT for dialysis patients with secondary hyperparathyroidism.

STUDY DESIGN

This is a retrospective review of 46 dialysis patients undergoing PTX from 2006 to 2017 at a 719-bed tertiary care hospital.

RESULTS

Calcium on postoperative day 1 was 7.7 ± 0.8 mg/dL for SPTX and 7.9 ± 1.3 mg/dL for TPTX-AT (p = 0.49). Parathyroid hormone values on postoperative day 1 were 32.6 ± 26.0 pg/mL for SPTX and 9.5 ± 4.2 pg/mL for TPTX-AT (p ≤ 0.05). Hospital length of stay was 3.7 ± 1.9 days for SPTX and 4.4 ± 3.5 days for TPTX-AT (p = 0.46). The required doses of calcium and calcitriol at discharge did not differ significantly. Reoperation for recurrence or persistence of disease was required in 6 SPTX patients and 2 TPTX-AT patients (p = 0.12). Parathyroid hormone values <15 pg/mL at long-term follow-up occurred in 5.6% of SPTX patients and 26.7% of TPTX-AT patients (p = 0.09). Parathyroid hormone values >200 pg/mL at long-term follow-up occurred in 38.9% of SPTX patients vs 6.7% of the TPTX-AT patients (p ≤ 0.05). Calcium supplementation at more than 6 months was required for 36.8% of SPTX and 71.4% of TPTX-AT patients (p < 0.05).

CONCLUSIONS

The long-term control of parathyroid hormone elevation and avoidance of recurrent disease is improved with TPTX-AT, but carries a higher risk of long-term hypocalcemia.

Treatment of hypocalcemia in hungry bone syndrome: A case report

INTRODUCTION

Hungry bone syndrome (HBS) is rapid, intense and prolonged hypocalcemia that follows parathyroidectomy. The focus of this paper is HBS in patients with secondary hyperparathyroidism (SHPT) due to end stage renal disease (ESRD). Various risk factors are correlated with developing HBS post-parathyroidectomy due to SHPT which include: old age (>60 years); the preoperative level of parathyroid hormone (PTH); increased osteoclasts; and evidence of bone disease before surgery.

PRESENTATION OF CASE

A 25-year-old woman, who underwent parathyroidectomy of all four parathyroid glands due to SHPT caused by ESRD. Her calcium deficit was prolonged, as expected in patients who undergo parathyroidectomy, however her calcium levels remained low despite unprecedented supplementation of elemental calcium and calcitriol.

DISCUSSION

Unfortunately, there is not enough data-based evidence to help prevent or minimize severe complications of hypocalcemia prior to parathyroidectomy. The main goal of treatment is replenishing the calcium deficiency through supplementation with calcium salts, high doses of active metabolites of vitamin D, and electrolytes.

CONCLUSION

The ultimate goal of reviewing and analyzing this particular case is to obtain a better understanding for the treatment of Hungry bone syndrome. Although, there are very few cases as severe as this patient, hopefully this case study will result in greater insight and lead to improvement in the overall treatment of hypocalcemia.

Resurgence of parathyroidectomy: evidence and outcomes

PURPOSE OF REVIEW

Parathyroidectomy (PTx) is the definitive therapy for refractory secondary hyperparathyroidism (SHPT). The drastic effects of PTx on biochemical parameters of SHPT increases the possibility that this intervention will lead to a reduction in the adverse outcomes related to uncontrolled SHPT.

RECENT FINDINGS

The effect of PTx on mortality and cardiovascular outcomes among dialysis patients with severe SHPT have been evaluated in many observational studies from different regions of the world, including Asia, Europe, North America, and South America. In all but one small study, there was a significant association of PTx with lower all-cause mortality. In addition, in all studies, there was a trend in favor of PTx for cardiovascular morbidity and mortality. The effect of PTx on fractures has been evaluated in only one epidemiological study from the United States, which demonstrated a significant association of PTx and lower hip and combined fractures.

SUMMARY

Although randomized evidence is lacking, these highly consistent results may suggest a strong beneficial effect of PTx on long-term clinical outcomes and eliminate the potential concern of low parathyroid hormone after PTx.

Hungry bone syndrome

PURPOSE OF REVIEW

In the United States, the number of parathyroidectomies among patients with chronic dialysis has remained stable in the last decade. A fall in serum calcium concentration is common postparathyroidectomy in patients with hyperparathyroidism, which usually resolves in 2-4 days. A severe drop in serum total calcium concentration less than 2.1 mmol/L and/or prolonged hypocalcemia for more than 4 days postparathyroidectomy is called hungry bone syndrome (HBS). Concomitant hypophosphatemia, hypomagnesemia, and hyperkalemia can be seen. Hypocalcemia and hypophosphatemia can persist for months to years. In contemporary clinical practice, HBS may be more commonly seen in patients with secondary compared to primary hyperparathyroidism. Preoperative radiological changes in bone, elevated serum alkaline phosphatase and parathyroid hormone (PTH) levels, and high numbers of osteoclasts on bone biopsy may identify patients at risk. Treatment consists of high-dose oral calcium and calcitriol supplementation. A low-dose pamidronate infusion 1-2 days prior to surgery may prevent HBS.

RECENT FINDINGS

Recent in-vitro studies reported net calcium movement into bone because of a sudden fall in serum PTH level after a prolonged period of elevation. This supports a previous hypothesis that a sudden drop in serum PTH level after surgery results in the unopposed action of osteoblasts and influx of calcium into bone.

SUMMARY

Incidence of HBS and its association with morbidity and mortality remains unclear in contemporary clinical practice. It is more common to encounter HBS in chronic dialysis patients with secondary hyperparathyroidism than those with primary hyperparathyroidism that undergo parathyroidectomies. Use of bisphosphonates to prevent HBS should be explored in future studies.

Impact of surgical parathyroidectomy on chronic kidney disease-mineral and bone disorder (CKD-MBD) - A systematic review and meta-analysis

For more than 6 decades, many patients with advanced chronic kidney disease (CKD) have undergone surgical parathyroidectomy (sPTX) for severe secondary hyperparathyroidism (SHPT) mainly based historical clinical practice patterns, but not on evidence of outcome.We aimed in this meta-analysis to evaluate the benefits and harms of sPTX in patients with SHPT. We searched MEDLINE (inception to October 2016), EMBASE and Cochrane Library (through Issue 10 of 12, October 2016) and website clinicaltrials.gov (October 2016) without language restriction. Eligible studies evaluated patients reduced glomerular filtration rate (GFR), below 60 mL/min/1.73 m² (CKD 3–5 stages) with hyperparathyroidism who underwent sPTX. Reviewers working independently and in duplicate extracted data and assessed the risk of bias. The final analysis included 15 cohort studies, comprising 24,048 participants. Compared with standard treatment, sPTX significantly decreased all-cause mortality (RR 0.74 [95% CI, 0.66 to 0.83]) in End Stage Kidney Disease (ESKD) patients with biochemical and / or clinical evidence of SHPT. sPTX was also associated with decreased cardiovascular mortality (RR 0.59 [95% CI, 0.46 to 0.76]) in 6 observational studies that included almost 10,000 patients. The available evidence, mostly observational, is at moderate risk of bias, and limited by indirect comparisons and inconsistency in reporting for some outcomes (eg. short term adverse events, including documented voice change or episodes of severe hypocalcaemia needing admission or long-term adverse events, including undetectable PTH levels, risk of fractures etc.). Taken together, the results of this meta-analysis would suggest a clinically significant beneficial effect of sPTX on all-cause and cardiovascular mortality in CKD patients with SHPT. However, given the observational nature of the included studies, the case for a properly conducted, independent randomised controlled trial comparing surgery with medical therapy and featuring many different outcomes from mortality to quality of life (QoL) is now very strong.

Pharmacological Management of Secondary Hyperparathyroidism in Patients with Chronic Kidney Disease

Secondary hyperparathyroidism (SHPT) is a common complication of chronic kidney disease (CKD) and is part of the CKD-mineral bone disorder (CKD-MBD). SHPT is associated with increased risk of fracture and mortality; thus, SHPT control is recommended as kidney function declines. Effective SHPT management becomes more difficult once skeletal and cardiovascular adverse effects associated with severe SHPT have become established. However, interventional studies to lower parathyroid hormone (PTH) have so far shown inconsistent results in improving patient-centred outcomes such as mortality, cardiovascular events and fracture. Pharmacological treatment effect on PTH level is also inconsistent between pre-dialysis CKD and dialysis patients, which adds to the complexity of SHPT management. This review aims to give an overview on the pathophysiology, pharmacological and non-pharmacological treatment for SHPT in CKD including some of the limitations of current therapeutic options.

An open-label, prospective pilot clinical study of denosumab for severe hyperparathyroidism in patients with low bone mass undergoing dialysis

CONTEXT

Denosumab is widely used for bone diseases with increased bone resorption. Its effectiveness in patients with severe secondary hyperparathyroidism on dialysis is unclear.

OBJECTIVE

This study aimed to evaluate the efficacy and safety of denosumab in patients with severe secondary hyperparathyroidism who are on dialysis.

DESIGN

This 6-month prospective, open-labeled study evaluated 12 patients (five women, seven men; mean age 53.5 ± 3.8 y). All had intact PTH (iPTH; > 1000 pg/mL), low bone mass (T-score < -1.0 SD), and bone pain and were poor surgical candidates. Serum calcium, phosphorus, alkaline phosphatase (AP), and iPTH levels were assessed at baseline and every month thereafter. Vertebral spine x-rays and bone mineral densities (BMDs) (lumbar spine and femoral neck) were assessed at the start and end of the study. All patients received denosumab (60 mg), calcitriol, phosphate binders, and dialysate calcium that were adjusted according to the biochemistry data.

RESULTS

The BMD increased in both the femoral neck (mean increase 23.7% ± 4.0%) and lumbar spine (17.1% ± 2.6%) after 6 months. In the first month, most patients had increased iPTH levels, which dramatically decreased from 1702.1 ± 181.9 to 518.8 ± 126.8 pg/mL by the end of the study after increasing the calcitriol dose. All patients had significant decreases in AP, calcium × phosphorus, and bone pain. Changes in femoral neck BMD correlated only with AP and iPTH levels.

CONCLUSIONS

Denosumab is effective in restoring bone mass and reducing bone pain in patients on dialysis with secondary hyperparathyroidism. It also allows for a more aggressive use of calcitriol to control hyperparathyroidism.

Is three-gland-or-less parathyroidectomy a clinical failure for secondary hyperparathyroidism?

OBJECTIVE

To compare the clinical and biochemical outcomes between adequate and inadequate parathyroidectomies in patients with chronic renal failure.

MATERIAL AND METHODS

All secondary hyperparathyroidism patients who were previously operated in the Marmara University Hospital Breast and Endocrine Surgery Unit were planned to be included in the study. Patients were divided into two groups according to their extent of surgery: "adequate" and "inadequate" surgery groups. "Adequate surgery" was regarded as either subtotal (3½) or total parathyroidectomy. Removing fewer than 3½ parathyroids was defined as "inadequate surgery." Demographic, preoperative clinical symptoms, and their severity, as well as biochemical (e.g., tCa, PTH) findings, were recorded. Patients were followed monthly. The course of biochemical findings (tCa, PTH, P, ALP) and symptoms (by a scoring system of 1-4) was determined by comparing preoperative findings to those at the patient's last follow-up. Primary outcome of the study was treatment failure (biochemical persistence/recurrence) rates in both study cohorts. Secondary outcomes of the study were the levels of biochemical findings and improvement rates of clinical symptoms after parathyroidectomy, as well as complication rates related to the initial surgery in each surgery cohort.

RESULTS

Forty-two patients with secondary hyperparathyroidism who underwent parathyroidectomy were included into the study. Twenty-six were male and 16 were female. Median age was 46. Forty (95%) patients had at least one symptom as the indication for surgery, whereas only 2 (5%) patients were asymptomatic, but biochemical findings were the indication. Twenty-two (52%) patients underwent adequate operation, whereas 20 (48%) patients had inadequate operation. Mean follow-up duration after initial parathyroidectomy was 60 [3-244] months. Significantly more patients (n=15; 75%) in the inadequate surgery group had biochemical persistence/recurrence when compared with those (n=8; 36%) who underwent adequate surgery (OR [odds ratio] 5.25; 95% CI 1.38-19.93; p=0.012). However, symptom improvement rates were similar in both adequate and inadequate surgery groups.

CONCLUSION

Although there is high biochemical treatment failure after inadequate parathyroidectomy in patients with renal hyperparathyroidism, clinical symptom improvement rates are also surprisingly high in this patient group. On the other hand, the adequate surgery group also had an increased biochemical failure rate well above expected in longer follow-ups.

The surgical management of renal hyperparathyroidism

Secondary and tertiary hyperparathyroidism (HPT) develop in patients with renal failure due to a variety of mechanisms including increased phosphorus and fibroblast growth factor 23 (FGF23), and decreased calcium and 1,25-dihydroxy vitamin D levels. Patients present with various bone disorders, cardiovascular disease, and typical laboratory abnormalities. Medical treatment consists of controlling hyperphosphatemia, vitamin D/analog and calcium administration, and calcimimetic agents. Improved medical therapies have led to a decrease in the use of parathyroidectomy (PTX). The surgical indications include parathyroid hormone (PTH) levels >800 pg/ml associated with hypercalcemia and/or hyperphosphatemia despite medical therapy. Other indications include calciphylaxis, fractures, bone pain or pruritis. Transplant recipients often show decreased PTH, calcium and phosphorus levels, but some will have persistent HPT. Evidence suggests that PTX may cause deterioration in renal graft function in the short-term calling into the question the indications for PTX in these patients. Pre-operative imaging is only occasionally helpful except in re-operative PTX. Operative approaches include subtotal PTX, total PTX with or without autotransplantation, and possible thymectomy. Each approach has its proponents, advantages and disadvantages which are discussed. Intraoperative PTH monitoring has a high positive predictive value of cure but a poor negative predictive value and therefore is of limited utility. Hypocalcemia is the most common complication requiring aggressive calcium administration. Benefits of surgery may include improved survival, bone mineral density and alleviation of symptoms.

Proton pump inhibitor omeprazole use is associated with low bone mineral density in maintenance haemodialysis patients

OBJECTIVE

Limited studies have shown that proton pump inhibitor (PPI) therapy may decrease bone density or insoluble calcium reabsorption through induction of hypochlorhydria. However, PPI therapy may also reduce bone resorption via inhibition of osteoclastic vacuolar proton pumps. The aim of this study was to determine whether the opposing effects of PPI therapy may cause clinically important alterations in bone mineral densitometry (BMD) parameters in maintenance haemodialysis patients.

METHODS

Sixty-eight maintenance haemodialysis patients were enrolled in this study. Patients were classified into two groups involving users of PPI therapy (omeprazole 20 mg/day, group 1, n = 36 patients) and non-users of acid suppression drugs (group 2, n = 32 patients). Patients had radius, hip and spine BMD assessed by dual-energy X-ray absorptiometry.

RESULTS

The mean duration of PPI therapy with omeprazole was 27 +/- 5 months. The users of PPI therapy had lower values of bone mineral density and T-scores at the anatomical regions than non-users of acid suppression drugs. Serum calcium and phosphate levels, calcium-phosphate product and serum intact parathormone levels and the ratio of users of vitamin D therapy were similar among groups. A mutivariable adjusted odds ratio for lower bone density associated with more than 18 months of omeprazole, when all the potential confounders were considered, was 1.31 in the proximal radius, 0.982 in the femur neck, 0.939 in the trochanter and 1.192 in the lumbal spine.

CONCLUSION

The present data suggest that PPI therapy should be cautiously prescribed in maintenance haemodialysis patients, especially with lower BMD values.

Effect of cinacalcet on hypercalcemia and bone mineral density in renal transplanted patients with secondary hyperparathyroidism

BACKGROUND

Persistent secondary hyperparathyroidism (SHP) is the most frequent cause of hypercalcemia observed in approximately 10% of renal transplanted (RT) patients 1 year after surgery. Persistent SHP with hypercalcemia is an important factor of bone loss after renal transplantation. This study prospectively evaluates the effects of cinacalcet therapy on serum calcium (SCa) and parathyroid hormone (PTH) blood levels, and basically on bone mineral density (BMD) in RT patients with persistent hyperparathyroidism.

METHODS

Nine RT patients (eight women, one man) with allograft function more than 6 months were included based on total SCa more than 10.5 mg/dL and intact parathyroid hormone (iPTH) concentration more than 65 pg/mL. After inclusion, patients started on a single daily oral dose of 30 mg of cinacalcet. At inclusion and every study visit blood levels of creatinine, Ca, P, alkaline phosphatase, iPTH 1,25- dihydroxyvitamin D3, and 25-hydroxyvitamin D3 were assessed. Baseline and at the end of study radial BMD were measured. Study follow-up was 12 months.

RESULTS

During the study period, SCa decreased from 11.72+/-0.39 to 10.03+/-0.54 mg/dL (P<0.001). iPTH decreased from 308.85+/-120.12 to 214.66+/-53.75 mg/dL (P<0.05). The mean serum creatinine decreased from 1.58+/-0.34 to 1.25+/-0.27 mg/dL (P=0.03) and the mean radial BMD increased from 0.881+/-0.155 to 0.965+/-0.123 gr/cm2 (P<0.05). There were no significant changes in the other parameters assessed. One patient was excluded for gastrointestinal intolerance.

CONCLUSIONS

In RT patients with hypercalcemia secondary to persistent SHP, cinacalcet corrects hypercalcemia and PTH, simultaneously improving BMD.

Fracture Risk after Parathyroidectomy among Chronic Hemodialysis Patients

The impact of parathyroidectomy (PTX) on the long-term risks for hip and other fractures is unknown. Uncontrolled case series have reported an increase in bone mineral density after PTX. However, very low serum parathyroid hormone levels have been associated with decreased bone mineral density, adynamic bone disease, and fractures. This study compared long-term fracture rates among hemodialysis patients who underwent PTX with a matched control group. Data were obtained from the US Renal Data System. Patients who underwent a first PTX while receiving hemodialysis were matched with up to three control patients by age, race, gender, year of dialysis initiation, primary cause of renal failure, and the dosage of intravenous vitamin D used before PTX. Patients with a history of fracture or renal transplantation were excluded. Study outcomes were incident hip, vertebral, and distal radius-wrist fractures identified using hospitalization codes. Incident hip fracture rates in the PTX and matched control groups were 6.0 and 9.3 fractures per 1000 person-years, respectively. After adjustment, PTX was associated with a significant 32% lower risk for hip fracture (95% confidence interval 0.54 to 0.86; P = 0.001) and a 31% lower risk for any analyzed fracture (95% confidence interval 0.57 to 0.83; P < 0.001) compared with matched control subjects. Fracture risks were lower among hemodialysis patients who underwent PTX compared with matched control subjects. Surgical amelioration of secondary hyperparathyroidism may outweigh the risk of parathyroid hormone oversuppression in terms of bone health.

25-Hydroxyvitamin D deficiency and diabetes predict reduced BMD in patients with chronic kidney disease

In this study of 242 patients with renal failure, women, patients with diabetes, and patients on peritoneal dialysis had the highest risk of 25-hydroxyvitamin D deficiency. Levels correlated positively to BMD Z scores, and hip BMD was inversely related to prevalent fracture. Increasing 25-hydroxyvitamin D levels may benefit these patients.

INTRODUCTION

25-Hydroxyvitamin D deficiency (<37 nM) is common in patients with chronic kidney disease (CKD) stage 5 (glomerular filtration rate < 15 ml/min/1.73 m(2) or on dialysis), but it is unclear if this deficiency is associated with bone disease and if supplementation is warranted.

MATERIALS AND METHODS

Blood samples were collected on 242 patients with CKD stage 5 caused by type 1 diabetes (33%), type 2 diabetes (2%), and other causes (65%), who were about to undergo kidney or kidney pancreas transplantation. Prevalent spinal fracture was assessed by X-ray and BMD by DXA.

RESULTS

25-Hydroxyvitamin D deficiency was present in 28% of patients with diabetes versus 12% without (p < 0.0001). Patients on peritoneal dialysis (PD) had lower levels of 25-hydroxyvitamin D than patients on hemodialysis (HD; 49 +/- 26 versus 77 +/- 34 nM; p < 0.0001), and women had lower levels than men (51 +/- 25 versus 77 +/- 35 pM; p < 0.0001). BMD Z scores were within 1 SD of the mean at all sites, except in patients with diabetes (femoral neck Z score, -1.07 +/- 1.2; p < 0.0001) and patients who had undergone parathyroidectomy (lumbar spine Z score, 1.03 +/- 1.34, femoral neck Z score, 1.24 +/- 1.35; p < 0.001 and p < 0.0001, respectively). In multiple stepwise linear regression analysis, levels of 25-hydroxyvitamin D correlated positively and intact PTH (iPTH) correlated negatively to Z scores at the lumbar spine and wrist. Time on dialysis correlated positively to Z scores at the femoral neck and lumbar spine. Diabetes and serum alkaline phosphatase levels correlated negatively with Z scores at the femoral neck. Lower femoral neck BMD was associated with an increased prevalence of vertebral fracture and fragility fracture at any site (p = 0.03 and p < 0.03, respectively).

CONCLUSIONS

This study of patients with CKD stage 5 identifies women, patients with diabetes, and patients on PD as being at particular risk of 25-hydroxyvitamin D deficiency. We describe positive associations of 25-hydroxyvitamin D levels and BMD Z scores and an association between femoral neck BMD and fragility fracture at any site. Treatment to improve 25-hydroxyvitamin D levels may benefit these patients.

Risk factors for decreased total body and regional bone mineral density in hemodialysis patients with severe secondary hyperparathyroidism

Hyperparathyroidism contributes significantly to decreased bone mineral density (BMD) in end-stage renal disease patients, but this negative influence is not homogeneous throughout the skeleton. We studied the BMD by dual-energy X-ray absorptiometry on total body and on different regions of the skeleton in 42 patients with severe hyperparathyroidism on hemodialysis. We also evaluated the relationship between different risk factors and BMD found on the regions examined in these patients. The legs and other sites where cortical bone predominate were mostly affected, whereas trabecular bone was relatively preserved. This is probably the result of the different effects of hyperparathyroidism on cortical and trabecular bone, but we cannot rule out the interference of ectopic calcifications and sclerotic lesions of vertebral end-plates falsely increasing lumbar spine BMD. The main determinants of low total-body BMD were, in order of importance, immobility, high intact parathyroid hormone levels, low body mass index, and low albumin. Eleven patients presented with pathologic fractures, mainly in the legs, and BMD was lower in this group than in patients without fractures. In conclusion, our study makes clear that hyperparathyroidism is a great threat to bone density in hemodialysis patients, mainly in the legs, the site mostly affected by fragility fractures in our patients. Physicians must worry not only with high parathyroid hormone levels, but also with the nutritional state of these patients.

Changes of bone remodeling immediately after parathyroidectomy for secondary hyperparathyroidism

BACKGROUND

Successful parathyroidectomy for secondary hyperparathyroidism alleviates bone pain and is followed by the development of hypophosphatemia and hypocalcemia, as well as an increase in bone mineral density. An increase in osteoblast surface (Ob.S/BS) is not observed several months after surgery. In this study, we investigated early bone changes at 1 week after parathyroidectomy and the mechanism underlying an increase in bone mineral density.

METHODS

Fourteen patients with severe secondary hyperparathyroidism underwent iliac bone biopsy before and 1 week after parathyroidectomy. Changes in histomorphometric parameters, including osteoclast surface (Oc.S/BS), eroded surface (ES/BS), erosion depth (E.De), fibrosis volume (Fb.V/TV), Ob.S/BS, osteoid volume (OV/BV), osteoid surface (OS/BS), and osteoid thickness (O.Th), were investigated. Changes in texture of mineralized bone and osteoid seams were also investigated.

RESULTS

Oc.S/BS (P < 0.001), ES/BS (P < 0.01), and E.De (P < 0.001) decreased, but Fb.V/TV did not change at 1 week postoperatively. In particular, osteoclasts disappeared in almost all patients. Ob.S/BS (P < 0.001) increased, and cuboidal osteoblasts were proliferating on the trabecular surface where osteoclasts had existed before parathyroidectomy. As a result, newly developed osteoblasts coexisted with fibrous tissue after surgery. OV/BV (P < 0.005), OS/BS (P < 0.005), and O.Th (P < 0.005) increased, with lamellar osteoid volume showing a particular increase. Bone mineralization continued despite the low postoperative serum parathyroid hormone level.

CONCLUSION

A rapid decrease in serum parathyroid hormone level after parathyroidectomy appears to suppress bone resorption, as well as cause a transient marked increase in bone formation and an increase in normal lamellar osteoid seams.

Surgical management of secondary hyperparathyroidism

Most patients with renal failure maintained on chronic dialysis have elevated parathyroid hormone (PTH) levels and PTH-mediated bone disease (secondary hyperparathyroidism [sHPT]). Elevated PTH production in this setting represents a progressive, exaggerated physiologic response to hypocalcemia by the parathyroid glands, and generalized growth of the parathyroids is an adaptive response to chronic stimulation. Effective medical strategies to reduce PTH secretion and PTH-mediated bone turnover in sHPT (eg, controlling hyperphosphatemia, normalizing serum calcium, and administering vitamin D analogs) has decreased the need for parathyroidectomy in recent years. However, failure of medical therapy because of inadequate treatment, persistent hyperphosphatemia, or acquired parathyroid neoplasia still leads to recommendations for parathyroidectomy in select patients. Furthermore, increased awareness of potential long-term, irreversible cardiovascular effects of uncorrected hyperparathyroidism has led some to advocate parathyroidectomy earlier in the course of this disease. This monograph will review parathyroidectomy for secondary and tertiary hyperparathyroidism.

Dialysis bone disease

The bone disease associated with end-stage renal failure (ESRD) and treatment are complex and multifactorial, and has changed in both clinical and imaging features over the past three decades. Whereas previously features of vitamin D deficiency (rickets/osteomalacia) and intense, and prolonged, secondary hyperparathyroidism (bone resorption, osteosclerosis, metastatic calcification) predominated, these features are now rarely evident radiologically. This has occurred through the better understanding of vitamin D metabolism and improvements in therapeutic management. However, metastatic calcification in soft tissues and 'adynamic" bone continue to be problematic. New complications have developed as a consequence of treatment (dialysis and transplantation), including amyloid deposition, noninfective sponyloarthropathy, osteonecrosis, and osteopenia/osteoporosis). Radiographs remain the most widely used imaging technique in examining for skeletal disease in patients with ESRD on maintenance dialysis. Occasionally, more sophisticated imaging (CT, MRI, nuclear medicine scanning) are helpful (parathyroid tumor localization, differentiation between infection and amyloid deposition). Developments in quantitative methods to assess bone density enable the effects of ESRD and treatment to be studied and monitored. Technical developments in computed tomography (rapid, multislice scanning) allow quantitation and monitoring of metastatic cardiac calcification in patients on hemodialysis, which has relevance to prognosis.

Parathyroidectomy in dialysis patients

Subtotal parathyroidectomy or total parathyroidectomy (PTx) with autotransplantation are surgical procedures considered while the patient is included on the waiting list for renal transplantation. Total PTx alone is based in the possibility that a fragment of tissue (nodular hyperplasia in particular) left in the same pathophysiological environment of long term dialysis would show the same behavior and reproduce in time the same clinicopathological picture. The persistence of uremia induces a continued growth stimulus developing residual hyperplasia and consequently a very high risk of recurrence. We performed total PTx alone in 15 uremic patients excluded for renal transplantation 10 patients with undetectable iPTH serum concentration and were followed up for 37 to 144 months. There was no evidence of clinical bone disease (bone pain or fractures). Bone mineral lumbar spine and hip density was measured at the end of follow-up. The z score data showed that all patients had a bone mass similar than that expected for their age. Bone biopsies performed in four patients showed a uniform picture of low turnover without aluminium staining. Calcification of small arteries (digital and arcade vessels in hands and feet) were evaluated pre and post total PTx alone in nine out of the 10 patients with undetectable PTH levels. The small vessel calcification was present in five patients at the moment of PTx. At the end of the long term follow-up only one patient showed progression. In conclusion, total PTx without autotransplantation is a very effective and adequate treatment for refractory severe hyperparathyroidism in patients excluded for renal transplantation. Aluminium related osteopathy post PTx is a risk to be controlled with aluminium "free" dialysis water and avoiding aluminium containing phosphate binders.