Parathyroidectomy in dialysis patients

[Risk factors affecting graft survival after parathyroidectomy and parathyroid autotransplantation in patients on maintenance hemodialysis]

OBJECTIVE

To investigate the risk factors affecting the survival of parathyroid autograft following total parathyroidectomy combined with autologous sternocleidomastoid muscle transplantation (TPTX + AT) in patients on maintenance hemodialysis (MHD) complicated with secondary hyperparathyroidism (SHPT).

OBJECTIVE

This retrospective study was conducted among the patients on maintenance hemodialysis with SHPT, who underwent successful parathyroidectomy and autotransplantation from January, 2010 to February, 2020 in our hospital. The clinical data and serum levels of calcium, phosphorus, intact parathyroid hormone, hemoglobin, and alkaline phosphatase (ALP) of the patients were collected. The enrolled patients were divided into survival group with bilateral forearm parathyroid hormone (iPTH) ratio > 1.5 and death group with a ratio < 1.5 at 2 weeks after surgery for comparison of the clinical data and perioperative indicators. The risk factors of postoperative parathyroid autograft survival were analyzed using logistic regression analysis.

OBJECTIVE

A total of 87 patients were included in the study, among whom the graft survival rate after parathyroid transplantation was 78.16%. In both groups, serum levels of calcium, phosphorus, iPTH and ALP decreased and hemoglobin level increased significantly at 1 week and 1, 2, 3, 6 and 12 months after surgery (P < 0.01). Logistic regression analysis showed that serum ALP level was an independent risk factor for graft survival following parathyroid autotransplantation [OR=1.003, 95% CI: 1.001-1.005, P=0.004].

OBJECTIVE

TPTX+AT is a safe and effective treatment for SHPT, and parathyroid autografts are less likely to survive following parathyroid transplantation in patients with high preoperative level of ALP.

Pediatric hyperparathyroidism: review and imaging update

Hyperparathyroidism, due to increased secretion of parathyroid hormones, may be primary, secondary or tertiary. Most pediatric patients with sporadic primary hyperparathyroidism will be symptomatic, presenting with either end-organ damage or nonspecific symptoms. In younger patients with primary hyperparathyroidism, there is a higher prevalence of familial hyperparathyroidism including germline inactivating mutations of the calcium-sensing receptor genes that result in either neonatal severe hyperparathyroidism or familial hypocalciuric hypercalcemia. Parathyroid scintigraphy and ultrasound are complementary, first-line imaging modalities for localizing hyperfunctioning parathyroid glands. Second-line imaging modalities are multiphase computed tomography (CT) and magnetic resonance imaging. In pediatrics, multiphase CT protocols should be adjusted to optimize radiation dose. Although, the role of these imaging modalities is better established in preoperative localization of hyperfunctioning parathyroid glands in primary hyperparathyroidism, the same principles apply in secondary and tertiary hyperparathyroidism. In this manuscript, we will review the embryology, anatomy, pathophysiology and preoperative localization of parathyroid glands as well as several subtypes of primary familial hyperparathyroidism. While most of the recent imaging literature centers on adults, we will focus on the issues that are pertinent and applicable to pediatrics.

Behavior of Bone Mineral Metabolism in Renal Posttransplantation Patients with Severe Hyperparathyroidism

BACKGROUND

Secondary hyperparathyroidism usually improves after renal transplantation. When it becomes persistent, it is associated with deleterious effects on the graft, bone demineralization, fractures, calcifications, and cardiovascular events. In this study we describe the development of cases of severe hyperparathyroidism occurring after renal transplantation.

OBJECTIVE

To describe the behavior of the indicators of bone mineral metabolism in the renal transplantation patient with severe secondary hyperparathyroidism before transplantation, treated with or without parathyroidectomy.

METHODS

This is a case series study conducted between 2004 and 2017 on renal transplantation patients presenting with PTH > 800 pg/mL or who required pretransplantation parathyroidectomy.

RESULTS

We found 36 patients with severe hyperparathyroidism, corresponding to 10.8% of transplantation recipients, with an average age of 54.5 years (±12.35). The median follow-up after transplantation was 128 months (16-159). Fourteen patients underwent parathyroidectomy before transplantation, with a median intact parathyroid hormone at the time of transplantation of 56 (3-382) pg/mL, with more episodes of hypocalcaemia and oral calcium requirement. The other patients were transplanted with a median intact parathyroid hormone of 1010 (range, 802-1919) pg/mL, reaching a median intact parathyroid hormone of 98.8 (43.8-203) at 3 years of follow-up. Only 2 patients underwent parathyroidectomy for tertiary hyperparathyroidism.

CONCLUSIONS

Renal transplantation improves secondary hyperparathyroidism. Sixty-eight percent of patients presented PTH of less than 130 pg/mL after renal transplantation. Only 2 patients underwent posttransplantation parathyroidectomy.

Surgical Outcomes of Subtotal Parathyroidectomy for Renal Hyperparathyroidism

OBJECTIVES

The aim of this study was to evaluate the effectiveness of subtotal parathyroidectomy for patients with renal hyperparathyroidism.

METHODS

We studied 25 patients with renal hyperparathyroidism who underwent subtotal parathyroidectomy from October 2002 to October 2017. We analyzed serum intact parathyroid hormone (iPTH), calcium, and inorganic phosphorus levels before and at multiple time points following surgery, and evaluated the surgical outcomes and complications.

RESULTS

Of the 25 patients, 13 (52%) were male and 12 (48%) were female, and the mean age was 53.4±9.3 years. The mean duration of dialysis before parathyroidectomy was 156.8±79.5 months. Mean preoperative serum iPTH and calcium levels were 1,199.0±571.3 pg/mL and 10.5±1.0 mg/dL, respectively. At 6 months postoperatively, the mean iPTH and calcium levels decreased to 49.2±47.6 pg/mL (P<0.01) and 8.0±1.0 mg/dL (P<0.01), respectively. Recurrent hyperparathyroidism occurred in two patients: one subsequently underwent kidney transplantation and the other continued hemodialysis and maintained normal calcium levels. One patient developed postoperative permanent hypoparathyroidism.

CONCLUSION

Subtotal parathyroidectomy is a safe and effective surgical treatment for renal 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.

Parathyroidectomy in dialysis patients: Indications, methods, and consequences

Secondary hyperparathyroidism, characterized by increased PTH synthesis and secretion, is often seen in advanced stages of chronic kidney disease. Excessive proliferation of parathyroid cells leads to the development of diffuse hyperplasia that subsequently progresses to nodular histology. Refractory hyperparathyroidism occurs when parathyroid glands fail to respond to medical therapy. Parathyroidectomy (PTX), surgical resection of parathyroid glands, is usually performed in cases of persistent serum levels of PTH above 1000 pg/mL associated with hypercalcemia or when hyperparathyroidism is refractory to conservative therapy. Parathyroidectomy can be carried out using different procedures: subtotal PTX or total PTX with or without parathyroid autotransplantation. Parathyroid surgery may have undesirable consequences due to PTH oversuppression, such as the development of adynamic bone disease; hungry bone syndrome is quite common after this surgery. However, PTX improves survival and parameters of mineral metabolism. Parathyroidectomy needs to be considered in those patients with severe hyperparathyroidism with a poor response to pharmacological treatment and with distinct undesirable effects of PTH on bone and mineral metabolism parameters.

The Calcium-Sensing Receptor Gene Polymorphism rs1801725 and Calcium-Related Phenotypes in Hemodialysis Patients

BACKGROUND/AIMS

The calcium-sensing receptor gene (CASR) rs1801725 variant is responsible for a non-conservative amino-acid change (A986S) in the calcium-sensing receptor cytoplasmic tail. We hypothesized that rs1801725 polymorphism might be helpful in understanding Ca-related abnormalities in HD patients.

METHODS

In 1215 subjects (245 on cinacalcet), we determined the associations of rs1801725 with secondary hyperparathyroidism (sHPT)-related laboratory parameters, PTH-decreasing effect of cinacalcet hydrochloride, coronary artery disease (CAD), myocardial infarction (MI), nephrolithiasis-related ESRD, and mortality. CASR rs7652589(AT) haplotypes and rs1801725 epistatic interactions with vitamin D signaling pathway genes were examined for associations with selected phenotypes.

RESULTS

The rs1801725 variant allele showed an increasing independent effect on plasma PTH (Pcorrected = 0.009). CASR rs7652589_rs1801725 AT haplotype was associated with 1.7-fold higher frequency of PTH levels over 437 pg/mL than the reference haplotype GG (P = 0.001). CASR rs7652589_rs1801725 AG haplotype was 1.5-fold more frequent in nephrolithiasis-related ESRD than the GG haplotype (P = 0.004). There were no significant associations between rs1801725, CAD, MI, and response to cinacalcet. Variant homozygosity of rs1801725 correlated independently with higher infection-related mortality compared with heterozygosity (HR 7.95, 95%CI 2.15 - 29.37, P = 0.003) and major homozygosity (HR 5.89, 95%CI 1.69 - 20.55, P = 0.040). CASR rs1801725 did not show epistatic interactions with vitamin D signaling pathway genes concerning tested associations.

CONCLUSION

The variant allele of CASR rs1801725 solely and together with the variant allele of rs7652589 increases risk of more advanced sHPT. Homozygosity of the rs1801725 variant allele contributes to infection-related mortality in HD patients.

PTH monitoring after total parathyroidectomy with forearm auto-transplantation: potential for spuriously high levels from grafted forearm

Background

We have identified a cause of falsely elevated parathyroid hormone (PTH) levels after total parathyroidectomy with forearm auto-transplantation (TPT-ATx). Our cases highlight the need to draw PTH samples remotely, away from forearm graft sites, to ensure accurate levels.

Case presentations

We report on four patients who were referred to our surgical team at an academic tertiary care center for what was perceived to be recurrent hyperparathyroidism 2–5 years following total parathyroidectomy with auto-transplantation. Further evaluation revealed highly discrepant results in these patients depending on where the blood was drawn, with spuriously high levels in blood drawn from the grafted arm (Range 337–3885 ng/l), and much lower levels when blood was drawn remotely away from the graft site (Range 9–242 ng/l). The difference in PTH level between the grafted forearm and remote site for these patients ranged between 328 and 3643 ng/l.

Over the period these cases were accrued (2008–2012), 89 patients underwent TPT-ATx in our institution. Therefore, our case report series suggests that this phenomenon will be evident to a clinically important extent in at least 4% of patients.

Conclusions

One can acquire spuriously high PTH levels from grafted forearms, leading to the false diagnosis of recurrent hyperparathyroidism. We recommend PTH levels be drawn remotely from graft sites to ensure accurate systemic levels are reflected.

Parathyroid ultrasonography and bone metabolic profile of patients on dialysis with hyperparathyroidism

AIM

To evaluate the parathyroid ultrasonography and define parameters that can predict poor response to treatment in patients with secondary hyperparathyroidism due to renal failure.

METHODS

This cohort study evaluated 85 patients with chronic kidney disease stage V with parathyroid hormone levels above 800 pg/mL. All patients underwent ultrasonography of the parathyroids and the following parameters were analyzed: Demographic characteristics (etiology of chronic kidney disease, gender, age, dialysis vintage, vascular access, use of vitamin D), laboratory (calcium, phosphorus, parathyroid hormone, alkaline phosphatase, bone alkaline phosphatase), and the occurrence of bone changes, cardiovascular events and death. The χ² test were used to compare proportions or the Fisher exact test for small sample frequencies. Student t-test was used to detect differences between the two groups regarding continuous variables.

RESULTS

Fifty-three patients (66.4%) had parathyroid nodules with higher levels of parathyroid hormone, calcium and phosphorus. Sixteen patients underwent parathyroidectomy and had higher levels of phosphorus and calcium × phosphorus product (P = 0.03 and P = 0.006, respectively). They also had lower mortality (32% vs 68%, P = 0.01) and lower incidence of cardiovascular or cerebrovascular events (27% vs 73%, P = 0.02). Calcium × phosphorus product above 55 mg²/dL² [RR 1.48 (1.06, 2.08), P = 0.03], presence of vascular calcification [1.33 (1.01, 1.76), P = 0.015] and previous occurrence of vascular events [RR 2.25 (1.27, 3.98), P < 0.001] were risk factors for mortality in this population. There was no association between the occurrence of nodules and mortality.

CONCLUSION

The identification of nodules at ultrasonography strengthens the indication for parathyroidectomy in patients with secondary hyperparathyroidism due to renal failure.

Adynamic bone disease: from bone to vessels in chronic kidney disease

Adynamic bone disease (ABD) is a well-recognized clinical entity in the complex chronic kidney disease (CKD)-mineral and bone disorder. Although the combination of low intact parathyroid hormone (PTH) and low bone alkaline phosphatase levels may be suggestive of ABD, the gold standard for precise diagnosis is histomorphometric analysis of tetracycline double-labeled bone biopsies. ABD essentially is characterized by low bone turnover, low bone volume, normal mineralization, and markedly decreased cellularity with minimal or no fibrosis. ABD is increasing in prevalence relative to other forms of renal osteodystrophy, and is becoming the most frequent type of bone lesion in some series. ABD develops in situations with reduced osteoanabolic stimulation caused by oversuppression of PTH, multifactorial skeletal resistance to PTH actions in uremia, and/or dysregulation of Wnt signaling. All may contribute not only to bone disease but also to the early vascular calcification processes observed in CKD. Various risk factors have been linked to ABD, including calcium loading, ageing, diabetes, hypogonadism, parathyroidectomy, peritoneal dialysis, and antiresorptive therapies, among others. The relationship between low PTH level, ABD, increased risk fracture, and vascular calcifications may at least partially explain the association of ABD with increased mortality rates. To achieve optimal bone and cardiovascular health, attention should be focused not only on classic control of secondary hyperparathyroidism but also on prevention of ABD, especially in the steadily growing proportions of diabetic, white, and elderly patients. Overcoming the insufficient osteoanabolic stimulation in ABD is the ultimate treatment goal.

Clinical significance of parathyroid intervention on CKD-MBD management

Recently published ‘Guidelines for the management of secondary hyperparathyroidism in chronic dialysis patients’ by the Japanese Society for Dialysis Therapy advocate that percutaneous ethanol injection into enlarged glands, which has been considered as the only alternative to parathyroidectomy (PTx), should be indicated in patients with a single enlarged parathyroid gland (estimated volume >500 mm³, or estimated major axis >10 mm), and that PTx should be recommended in patients with multiple enlarged glands. Cinacalcet cannot achieve optimal control of chronic kidney disease–mineral bone disorder in all patients, and parathyroid intervention will be required in a considerable number of patients with refractory secondary hyperparathyroidism.

Serum levels of intact parathyroid hormone is a prognostic indicator of dialyzed patients: the Nishinomiya study

Patients with chronic kidney disease on dialysis are at higher risk for cardiovascular disease (CVD), which is the greatest cause of mortality. The target range of serum intact parathyroid hormone (iPTH) for prognosis, 60 to 240 pg/mL, was recommended by the Japanese Society for Dialysis Therapy guidelines. To investigate the impact of this iPTH target on CVD, dialysis patients were enrolled. A total 287 participants were observed. At the start of the study, serum iPTH levels, routine laboratory parameters, and certain factors related to CVD were evaluated. A survival analysis (Kaplan-Meier curve) was used. After 10 years of follow-up, 19.2% of patients had CVD. The subjects were divided into three groups according to their iPTH level at baseline based on the target range of 60 to 240 pg/mL: Low, Middle, and High groups. CVD was more common in the High and Low groups compared to the Middle group. A lower risk of CVD was evident in the extended dialysis patients with a range of 60 to 240 pg/mL iPTH. Further studies are needed to evaluate the impact of the iPTH level on poor outcome.

Radioguided parathyroidectomy in forearm graft for recurrent hyperparathyroidism

We report a peculiar case of recurrent hyperparathyroidism caused by hyperplasia of a forearm graft implanted following a total parathyroidectomy in a 38-year-old patient with chronic renal failure. The forearm graft hyperplasia was detected using (99)Tc(m)-sestamibi scanning, which identified hyperplastic transplanted parathyroid tissue in the forearm of the patient. During the initial surgery, the surgeon failed to mark the parathyroid tissue with sutures or clips to facilitate locating it. Therefore, we referred the patient for radioguided surgery. This surgical procedure allowed us to locate and completely remove the hyperfunctioning transplanted parathyroid tissue.

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.

Use of percutaneous ethanol injection therapy for recurrent secondary hyperparathyroidism after subtotal parathyroidectomy

We evaluated the efficacy of percutaneous ethanol injection therapy (PEIT) as a therapeutic option for recurrence of secondary hyperparathyroidism after subtotal parathyroidectomy in ESRD patients. Six patients underwent PEIT. A mean of 1.3 ± 0.8 ethanol injections was performed. Nodular volume was 1.5 ± 1.7 cm³, and 2.8 ± 2.8 cm³ of ethanol was injected per patient. After ethanol injection PTH decreased significantly (1897 ± 754 to 549 ± 863 pg/mL (P < .01)). There was also a reduction in serum calcium, phosphorus and calcium-phosphorus product. A positive and significant correlation was found between nodular volume with ethanol injected and time from parathyroidectomy. Only one patient required hospitalization due to severe hypocalcaemia. In other two cases, local discomfort and temporary mild dysphonia were registered. PEIT is an effective treatment to control recurrences of secondary hyperparathyroidism postsubtotal parathyroidectomy.

Ultrasound features of malignancy in the preoperative diagnosis of parathyroid cancer: a retrospective analysis of parathyroid tumours larger than 15 mm

OBJECTIVE

Nearly all reported parathyroid cancers are >15 mm at presentation. The objective was to identify ultrasound criteria of malignancy in parathyroid lesions of >15 mm in size.

MATERIALS AND METHODS

This study was approved by a local ethics committee. A retrospective review of patients identified from a database from 2004-2009 was performed. All patients underwent ultrasound imaging according to the protocol. Two trained observers categorized findings using the pre-determined features: shape, calcification, pattern of vascularity, local infiltration and internal lesion gray scale appearances.

RESULTS

Sixty-nine patients (mean age 54.3 years, range 19-79 years; male = 16, female = 53) fulfilled the criteria of a parathyroid lesion >15 mm; 8/69 (11.6%) with parathyroid cancer and 61/69 (88.4%) with benign solitary parathyroid adenoma. A high positive predictive value (PPV) for cancer was identified for infiltration (PPV 100%) and calcification (PPV 100%), whilst a high negative predictive value (NPV) was found for the absence of suspicious vascularity (NPV 97.6%), a thick capsule (NPV 96.7) and inhomogeneity (NPV 100%).

CONCLUSION

In lesions >15 mm systematic ultrasound assessment of specific features provides a valuable tool to identify parathyroid cancers before surgery.

[Surgical treatment of secondary hyperparathyroidism in patients with chronic renal failure]

OBJECTIVE

To identify the indications for subtotal parathyroidectomy (PTX) in secondary hyperparathyroidism (SHPT) and report postoperative, early and late complications of PTX.

PATIENTS AND METHODS

We conducted a retrospective study of subjects with chronic renal failure operated in Tunisian hospitals who received subtotal PTX over 10 years from January 1997 to December 2007. We analyzed the clinical, biological and radiological parameters pre- and postoperatively.

RESULTS

We included 70 patients with average age of 39.4 years, 55.7% men and 44.3% in dialysis for 7.75 ± 4.8 years before PTX. The initial nephropathy was interstitial in 50% of cases. No cases of diabetic nephropathy have been reported. The clinical signs were bone pain (88.6%), muscle pain (85.6%), pruritus (81.4%). Radiological signs of osteitis fibrosa were observed in the majority of patients mainly resorption of extremities (92.9%), thinning of cortical (85.7%) and osteosclerosis (87.1%). The most common indication of PTX (85.7% of cases) was the persistence of serum PTH of more than 800 pg/ml associated with hypercalcemia and/or hyperphosphatemia refractory to medical treatment. A subtotal PTX (3/4 or 7/8) was performed after ultrasound and scintigraphy in the majority of cases. The histology of the parathyroid glands showed diffuse hyperplasia (51.4%), nodular hyperplasia (45.7%) and adenoma (2.8%). The postoperative evolution was marked by an improvement of the clinical and radiological criteria in 80% of cases. A PTH level of less than 15 pg/ml was rarely observed (10% of cases), and a PTH level of more than 300 pg/ml concerned 13% of patients. We noted a low morbidity and mortality (no cases laryngeal paralysis or cervical hematoma).

CONCLUSION

Surgical treatment of SHPT in Tunisia is very effective in our experience. The biological results are comparable to treatment with calcimimetics, not available in Tunisia and whose price is higher. An early treatment of disorders of bone and mineral metabolism should reduce the incidence of SHPT.

Evaluation of intraoperative parathormone measurement for predicting successful surgery in patients undergoing subtotal/total parathyroidectomy due to secondary hyperparathyroidism

OBJECTIVES/BACKGROUND

The aim of this study is to investigate the predictive value of intraoperative parathormone measurement addressing successful surgical resection in patients with secondary hyperparathyroidism.

METHODS

The study included 42 consecutive patients operated on between May 2006 and July 2008. Patients were grouped according to successful surgery (Group 1, n = 36) and persistent postoperative hyperparathyroidism (Group 2, n = 6). Serum phosphorus (P), total calcium (tCa), ionized calcium (iCa), intact parathormone (iPTH), and alkaline phosphatase (ALP) were drawn preoperatively and intraoperatively upon 15 minutes after completion of resection (iPTH(15)). The rate of decrease of pith detected by iPTH(15) compared to preoperative values was calculated (iPTH(%)).

RESULTS

Preoperative P, tCa, iCa, iPTH, and ALP were comparable. Subtotal parathyroidectomy (sPx) (n = 27) and total parathyroidectomy with autotransplantation (tPx) (n = 15) were performed. Mean iPTH(15) value, iPTH(%) rates were 145.9 +/- 12.3 pg/mL, % 91.6 +/- 0.7, and 522.5 +/- 85.4 pg/mL, % 75.1 +/- 2.0 (P = ,001) in Groups 1 and 2, respectively. Mean serum tCa and iCa at POD#1 in Group 1 were 7.6 +/- 0.1 mg/dL, 0.910 +/- 0.4 mmol/L, and Group 2 were 8.3 +/- 0.3 mg/dL, 1.050 +/- 0.4 mmol/L (P < .05), respectively. ALP levels were similar.

CONCLUSION

iPTH(15) value and iPTH(%) rate accurately predicts the completeness of resection in secondary hyperparathyroidism. The rate of decrease in serum iPTH detected intraoperatively compared to preoperative baseline levels exceeding 90% in sPx, 95% in tPx, accurately predicts the success of surgery. Postoperative normocalcemia without calcium replacement would raise a suspicion about completeness of surgical resection.

Viability and functionality of fresh and cryopreserved human hyperplastic parathyroid tissue tested in vitro

BACKGROUND/AIMS

This study aimed to test the viability and functionality of fresh and cryopreserved human hyperplastic parathyroid glands cultured in vitro.

METHODS

Small fragments of 18 parathyroid glands from 18 patients with secondary hyperparathyroidism were cultured in vitro, freshly or after cryopreservation, during 60 h. Cell viability and functionality of the parathyroid fragments exposed to calcium and calcitriol were studied.

RESULTS

Human parathyroid glands obtained from renal patients with secondary hyperparathyroidism maintained their viability and functionality for 60 h in culture. Sixty percent of the fresh but only 10% of the cryopreserved parathyroid glands showed the expected response with higher intact parathyroid hormone secretion when cultured with 0.6 mM calcium compared to 1.2 mM calcium. On the contrary, 44 of fresh and 40% of cryopreserved glands behaved in the same manner, showing a similar decrease in intact parathyroid hormone synthesis and secretion when cultured with calcitriol (10(-8)M).

CONCLUSION

These results demonstrate differences in the response to calcium between fresh and cryopreserved glands and no differences in the response to calcitriol. This in vitro culture method may be useful to discriminate between responsive and nonresponsive hyperplastic human parathyroid glands.

Rapid recurrence of hyperparathyroidism from both nodularly hyperplastic autograft at forearm and residual tissues at neck after parathyroidectomy in a hemodialysis patient with calciphylaxis

A 42-year-old woman underwent hemodialysis secondary to diabetic nephropathy. Total parathyroidectomy with forearm autograft was performed due to secondary hyperparathyroidism (HPT) complicated with calciphylaxis. Rapidly progressive enlargement of autograft with unusual "gourd-shape" developed, and then it was removed. Pathologic examination of the autograft disclosed multinodular hyperplasia. Residual parathyroid gland in the retrothyroid region was found later. Rapidly recurrent HPT originating from both the residual parathyroid tissues and the enlarged autograft within such short time after parathyroidectomy is rare in the literature. The multinodular hyperplasia pattern of the parathyroid gland may be a major factor for such rapid recurrence. In addition to good control of calcium and phosphate, regular follow-up of parathyroid hormone level and imaging studies of not only autografted gland at the forearm but also possibly residual parathyroid tissues at the neck are important for monitoring recurrence in maintenance hemodialysis patients after parathyroidectomy with forearm autograft, especially in those with pathologic type of nodular hyperplasia and calciphylaxis.

Cinacalcet HCl: a novel therapeutic for hyperparathyroidism

Hyperparathyroidism (HPT) is a significant clinical concern for patients with a variety of diseases, notably the secondary HPT associated with chronic kidney disease requiring dialysis. Secondary HPT is associated with elevated para-thyroid hormone (PTH) levels, decreased levels of 1,25 dihydroxyvitamin D, and disordered mineral levels (usually high calcium and phosphorus). If not controlled, secondary HPT can result in bone disease, vascular calcification, and ultimately, patient mortality. Established, conventional therapies, such as 1,25dihydroxyvitamin D analogues (vitamin D analogues) and phosphate binders, have proven to be inadequate in enabling patients to meet the National Kidney Foundation's-Kidney Disease Outcomes Quality Initiative (NKF-K/DOQI) treatment goals for PTH, calcium and phosphorus levels. A novel therapeutic, cinacalcet HCl (formerly AMG 073; Sensipar in the US and Mimpara in Europe; Amgen, Inc.), binds directly to the calcium-sensing receptor (CaR) on the cells of the parathyroid gland, increasing the receptor's sensitivity to calcium and reducing PTH, serum calcium and phosphorus levels. Treatment with cinacalcet in clinical trials has safely and effectively improved achievement of the NKF-K/DOQI goals. Cinacalcet has also reduced serum calcium levels in patients with primary HPT, including parathyroid carcinoma, in the clinical trial setting. Evidence suggesting the utility of cinacalcet in these diseases and the potential for additional therapeutic applications will be discussed.

Survival following parathyroidectomy among United States dialysis patients

BACKGROUND

Secondary hyperparathyroidism (SHPTH) is highly prevalent among persons with end-stage renal disease (ESRD). SHPTH has been linked to uremic bone disease, vascular calcification, and a higher risk of death. Parathyroidectomy (PTX) can dramatically reduce parathyroid hormone (PTH) and phosphate levels; however, the relationship between PTX and survival is not known.

METHODS

We conducted an observational matched cohort study utilizing data from the United States Renal Database System (USRDS) in which 4558 patients undergoing a first PTX while on hemodialysis or peritoneal dialysis were individually matched by age, race, gender, cause of ESRD, dialysis duration, prior transplantation status, and dialysis modality to 4558 control patients who did not undergo PTX. Patients were followed from the date of PTX until they died or were lost to follow-up.

RESULTS

The 30-day postoperative mortality rate following PTX was 3.1%. Long-term relative risks of death among patients undergoing PTX were estimated to be 10% to 15% lower than those of matched control patients not undergoing surgery. Survival curves between the 2 groups crossed 587 days following PTX. Median survival was 53.4 months (95% CI: 51.2-56.4) in the PTX group, and 46.8 months (95% CI: 44.7-48.9) in the control group.

CONCLUSION

PTX was associated with higher short-term, and lower long-term, mortality rates among U.S. patients receiving chronic dialysis. Measures to attenuate SHPTH may play an important role in reducing mortality among patients with end-stage renal disease.

Re-operation for hyperparathyroidism

INTRODUCTION

Re-operation for hyperparathyroidism (HPT) represents a challenge for experienced endocrine surgeons. The present study reviews the technical and pathological factors for failure of initial surgery and identifies strategies to approach re-operative parathyroidectomy.

METHODS

Clinical details, operation notes, pathology, localization studies and complications for re-operative cases performed by three surgeons were reviewed.

RESULTS

Over a 10-year period there were 40 re-operative cases with a 98% success rate. There were 31 patients with primary HPT, 21 with persistent primary (PP) and 10 with recurrent primary (RP). Multigland disease (MGD) was present in 19 of the 31 (61%) primary HPT cases. The culprit gland was ectopic in 14 cases, at a normal location in 10 and there was regrowth at previously excised sites or remnant disease in 10. There were nine patients with secondary HPT, four with persistent secondary (PS) and five with recurrent secondary (RS). The culprit gland was ectopic in five, at a normal location in four and regrowth at a previously excised site in two. Pre-operative investigations were employed in all cases and the most helpful were sestamibi scan (S) and selective venous sampling (SVS) for parathyroid hormone (PTH) concentration. True positive localizations for S was in 20 of 34 cases (59%), SVS in seven of nine (78%), computed tomography (CT) in seven of 17 (41%) and ultrasound scan (USS) in 10 of 28 (36%).

CONCLUSIONS

Re-operative parathyroidectomy can be performed by experienced surgeons with a very high success rate and minimal complications.

Parathyroidectomy: whom and when?

Hyperparathyroidism (HPT) is common in patients on dialysis, and parathyroidectomy (PTx) is often required. We present a retrospective, descriptive analysis of data corresponding to 148 patients on dialysis undergoing PTx due to severe refractory HPT (PTH 1401 +/- 497 pg/mL, Ca 10.6 +/- 0.8 mg/dL, P 6.9 +/- 1.7 mg/dL). Demographic data were compared with those recorded in 309 patients on dialysis not subjected to PTx who were managed at the same hospital. In the PTx group, the factors age (49.3 +/- 14 years), male gender (48.6%), and diabetes (0.7%) were significantly lower than in the non-PTx group (61.5 +/- 14.9 years, male gender 59%, diabetes 19.4%), while time on dialysis was longer (8.6 +/- 5.8 vs. 5.5 +/- 5.4 years). In 129 of the study patients (87.4%), four or more glands were identified, and total PTx plus autotransplantation (AT) in the forearm was performed. In the remaining 19 patients, two to three glands were identified, and AT was not undertaken. Four of the 19 patients were successfully operated on again for persistent HPT, seven showed PTH levels <250 pg/mL, and eight maintained severe HPT. Perioperative complications included one death due to cardiac insufficiency, two repeat operations due to bleeding, and one patient with chronic hoarseness. Hospital stay was prolonged in 20% of patients due to a hungry bone syndrome. Among those patients with PTx and AT, HPT recurred in 21 patients (16.2%) at 3.1 +/- 2.3 years. In 13 of these patients, autograft was removed at 7.5 +/- 2.9 years. Serum calcium and phosphate levels improved after PTx, and these results were maintained for 5 years (9.6 +/- 0.8 and 4.2 +/- 1.2 mg/dL, respectively). In conclusion, PTx with AT is a safe option for the treatment of severe HPT that is accompanied by low morbidity and mortality and a good outcome. Medical treatment should not be prolonged at the expense of long repeated bouts of hypercalcemia and/or hyperphosphatemia with their irreversible consequences.