Total parathyroidectomy with autotransplantation versus subtotal parathyroidectomy for renal hyperparathyroidism: A systematic review and meta-analysis

Parathyroid Imaging

Primary hyperparathyroidism (1° HPT) is a relatively common endocrine disorder usually caused by autonomous secretion of parathormone by one or several parathyroid adenomas. 1° HPT causing hypercalcemia, kidney stones and/or osteoporosis should be treated whenever possible by parathyroidectomy. Accurate preoperative location of parathyroid adenomas is crucial for surgery planning, mostly when performing minimally invasive surgery. Cervical ultrasonography (US) is usually performed to localize parathyroid adenomas as a first intention, followed by 99mTc- sestamibi scintigraphy with SPECT/CT whenever possible. 4D-CT is a possible alternative to 99mTc- sestamibi scintigraphy. Recently, 18F-fluorocholine positron emission tomography/computed tomography (18F-FCH PET/CT) has made its way in the clinics as it is the most sensitive method for parathyroid adenoma detection. It can eventually be combined to 4D-CT to increase its diagnostic performance, although this results in higher dose exposure to the patient. Other forms of hyperparathyroidism consist in secondary (2° HPT) and tertiary hyperparathyroidism (3° HPT). As parathyroidectomy is not usually part of the management of patients with 2° HPT, parathyroid imaging is not routinely performed in these patients. In patients with 3° HPT, total or subtotal parathyroidectomy is often performed. Localization of hyperfunctional glands is an important aid to surgery planning. As 18F-FCH PET/CT is the most sensitive modality in multigland disease, it is the preferred imaging technic in 3° HPT patients, although its cost and availability may limit its widespread use in this setting.

Investigating the effectiveness of intraoperative rapid parathyroid hormone assay in parathyroidectomy surgery in patients with secondary hyperparathyroidism

INTRODUCTION

The use of Rapid Intraoperative parathyroid hormone (Io-PTH) assay during surgery in the management of parathyroid tissue in cases of primary hyperparathyroidism has been proven to be effective, while its utilization in secondary hyperparathyroidism (SHPT) has been rarely reported. In the present study, we aim to demonstrate the application of rapid Io-PTH assay in patients with SHPT following chronic kidney disease undergoing parathyroidectomy surgery.

METHOD

In this prospective study, five blood samples were taken from patients undergoing parathyroidectomy and upper thymectomy. Among the samples, two were pre-excision, including prior to the first incision, after exploration, and before parathyroids resection. Two additional samples were taken 10 and 20 min after the excision of the parathyroid glands. Another sample was collected twenty-four hours after the operation. Serum Calcium levels and PTH levels were evaluated and analyzed.

RESULTS

We successfully managed SHPT in all 36 patients in our study. The patients included 24 males (66.7%) with a mean age of 49.97 ± 14.92. The mean PTH decreased significantly at 10 min, 20 min, one day, and six months after surgery (P < 0.001). The highest reduction occurred 10 min after removal of the parathyroid glands so the mean PTH compared to time zero was reduced from 1737 to 439, and in 100% of cases, more than 50% reduction was seen in PTH.

CONCLUSION

A 60% or more reduction in PTH Rapid at 10 min after parathyroidectomy has an accuracy of 94.4% and a positive predictive value of 100%. Thus, if the PTH level does not decrease by more than 60% at 10 min or more than 80% at 20 min, tissue exploration is continued with the aim of finding the ectopic parathyroid gland.

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.

Mineral Bone Disorders in Kidney Disease Patients: The Ever-Current Topic

Chronic kidney disease (CKD) is a complex and multifactorial disease, and one of the most prevalent worldwide. Chronic kidney disease–mineral bone disorders (CKD–MBD) with biochemical and hormonal alterations are part of the complications associated with the progression of CKD. Pathophysiology of CKD–MBD focused on abnormalities in serum levels of several biomarkers (such as FGF-23, klotho, phosphate, calcium, vitamin D, and PTH) which are discussed in this review. We therefore examine the prognostic association between CKD–MBD and the increased risk for cardiovascular events, mortality, and CKD progression to end-stage kidney disease (ESKD). Lastly, we present specific treatments acting on CKD to prevent and treat the complications associated with secondary hyperparathyroidism (SHPT): control of hyperphosphatemia (with dietary restriction, intestinal phosphate binders, and adequate dialysis), the use of calcimimetic agents, vitamin D, and analogues, and the use of bisphosphonates or denosumab in patients with osteoporosis.

Minimally invasive video-assisted parathyroidectomy (MIVAP) versus conventional parathyroidectomy for renal hyperparathyroidism: a retrospective multicenter study

To compare minimally invasive video-assisted parathyroidectomy (MIVAP) versus conventional surgery for renal hyperparathyroidism (rHPT). Between 2006 and 2020, 53 patients underwent MIVAP and 182 underwent conventional parathyroidectomy for rHPT at the Kliniken Essen-Mitte and Knappschaftskrankenhaus Bochum, respectively. Two propensity score-matched groups were retrospectively analyzed: the MIVAP group (VG; n = 53) and the conventional group (CG; n = 53). To assess long-term results, the patients were questioned prospectively (VG; n = 17, and CG; n = 26). The VG had a smaller incision (2.8 vs. 4.8 cm), shorter operation duration (81.0 vs. 13.9 min), and shorter duration of stay (2.4 vs. 5.7 days) (p < 0.0001) but a smaller drop in parathyroid hormone (PTH) postoperatively (81.3 vs. 85.5%. p = 0.022) than the CG. The conversion rate was 9.4% (n = 5). The VG had better Patient Scar Assessment Scale (PSAS) scores (10.8 vs. 11.7 p = 0.001) but worse SF-12 health survey scores (38.7 vs. 45.8 for physical health and 46.7 vs. 53.4 for mental health) (p < 0.0001). The PTH level at follow-up was higher in the VG (162.7 vs. 59.1 ng/l, p < 0.0001). There were no differences in morbidity, number of removed parathyroid glands, disease persistence, late rHPT relapse and need for repeat surgery between groups. MIVAP was superior to conventional parathyroidectomy regarding aesthetic outcomes and cost effectiveness. Conventional surgery showed better control of PTH levels and health scores on follow-up than MIVAP, without any impact on rHPT relapse and need for repeat surgery.

Trail registration number and date of registration: DRKS00022545 on 14.12.2020.

OUP accepted manuscript

Background

Several studies have reported on the use of intraoperative parathyroid hormone (ioPTH) measurements during parathyroidectomy (PTX) for renal hyperparathyroidism (rHPT), but there is no consensus on whether it is helpful and, if so, what protocol should be used. Therefore, the literature was systematically reviewed to assess a correlation between ioPTH and early postoperative parathyroid hormone (PTH) levels in patients undergoing PTX for rHPT, separately for those on dialysis and those with a functioning renal transplant.

Methods

A systematic literature search was performed in electronic databases. Quality assessment was performed using the Quality In Prognosis Studies tool. Mean ioPTH values were calculated at different time points and correlated to the postoperative PTH levels within 1 month. Fixed-effect and random-effects models were performed to assess the mean ioPTH levels at 10 or 20 min after resection (T10 and T20). Stratified analyses were performed for patients on dialysis and those with a functioning renal transplant.

Results

Of the 3087 records screened, 14 studies were included, including some 1177 patients; 1091 were on dialysis and 86 had a functioning kidney transplant. Risk of bias was moderate for most studies. For patients on dialysis, T10 and T20 mean ioPTH levels were 32.1 (95 per cent c.i. 24.3 to 39.9) pmol/l and 15.4 (95 per cent c.i. 7.8 to 22.9) pmol/l) in the random effects meta-analysis. Between individual studies, ioPTH ranged from 4.0–65.1 pmol/l at T10 and 8.6–25.7 pmol/l at T20. T10 and T20 ioPTH were 9.6 and 4.1 times the postoperative PTH—after T20 ioPTH stabilized in those on dialysis. In patients with a functioning renal transplant, ioPTH levels seemed to plateau after 10 min and measured 2.6 times the postoperative PTH.

Conclusion

There is a strong correlation between ioPTH and early postoperative PTH levels, indicating that ioPTH is potentially a useful instrument during PTX in patients with rHPT. For patients on dialysis, at T20 ioPTH levels have stabilized and are approximately four times the postoperative PTH. Therefore, it is recommended to use ioPTH 20 min after resection in patients on dialysis, which might be longer than necessary for those with a kidney transplant.

OUP accepted manuscript

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

Management of primary and renal hyperparathyroidism: guidelines from the German Association of Endocrine Surgeons (CAEK)

BACKGROUND AND AIMS

The purpose of this review is to provide updated recommendations for the surgical management of primary (pHPT) and renal (rHPT) hyperparathyroidism, formulating a new guideline of the German Association of Endocrine Surgeons (CAEK).

METHODS

Evidence-based recommendations for the diagnosis and therapy of pHPT and rHPT were assessed by a multidisciplinary panel using PubMed for a comprehensive literature search together with a structured consensus dialogue (S2k guideline of the Association of the German Scientific Medical Societies, AWMF).

RESULTS

During the last 20 years, a variety of new preoperative localization procedures, such as sestamibi-SPECT, 4D-CT, and various PET/CT procedures, were established for pHPT. High-resolution imaging, together with intraoperative parathyroid hormone (IOPTH) measurement, enabled focused or minimally invasive surgery to become the most favored surgical technique. Patients with pHPT and nonlocalizing imaging have a higher risk of multiglandular disease. Surgical therapy provides very high cure rates, with a clear relation to the surgeon's experience in parathyroid procedures. Reoperative parathyroidectomy, children with pHPT or familial forms, and parathyroid carcinoma are addressed and require special surgical expertise. A multidisciplinary team of experienced nephrologists, transplant, and endocrine surgeons should assess the diagnosis and treatment of renal HPT.

CONCLUSION

Surgery is the only curative treatment for pHPT and should be considered for all patients with pHPT. For rHPT, a more selective approach is required, and parathyroidectomy is indicated only when conservative treatment options fail. In parathyroid carcinoma, the adequacy of local resection influences local disease control.

Bone Mineral Disease After Kidney Transplantation

Chronic kidney disease-mineral bone disorder (CKD-MBD) after kidney transplantation is a mix of pre-existing disorders and new alterations. The final consequences are reflected fundamentally as abnormal mineral metabolism (hypercalcemia, hypophosphatemia) and bone alterations [high or low bone turnover disease (as fibrous osteitis or adynamic bone disease), an eventual compromise of bone mineralization, decrease bone mineral density and bone fractures]. The major cause of post-transplantation hypercalcemia is the persistence of severe secondary hyperparathyroidism, and treatment options include calcimimetics or parathyroidectomy. On turn, hypophosphatemia is caused by both the persistence of high blood levels of PTH and/or high blood levels of FGF23, with its correction being very difficult to achieve. The most frequent bone morphology alteration is low bone turnover disease, while high-turnover osteopathy decreases in frequency after transplantation. Although the pathogenic mechanisms of these abnormalities have not been fully clarified, the available evidence suggests that there are a number of factors that play a very important role, such as immunosuppressive treatment, persistently high levels of PTH, vitamin D deficiency and hypophosphatemia. Fracture risk is four-fold higher in transplanted patients compared to general population. The most relevant risk factors for fracture in the kidney transplant population are diabetes mellitus, female sex, advanced age (especially > 65 years), dialysis vintage, high PTH levels and low phosphate levels, osteoporosis, pre-transplant stress fracture and high doses or prolonged steroids therapy. Treatment alternatives for CKD-MBD after transplantation include minimization of corticosteroids, use of calcium and vitamin D supplements, antiresorptives (bisphosphonates or Denosumab) and osteoformers (synthetic parathyroid hormone). As both mineral metabolism and bone disorders lead to increased morbidity and mortality, the presence of these changes after transplantation has to be prevented (if possible), minimized, diagnosed, and treated as soon as possible.

Muscle strength, physical performance, and metabolic changes after subtotal parathyroidectomy for secondary hyperparathyroidism

BACKGROUND

Hyperparathyroidism in patients on chronic hemodialysis presents with bone pain, pruritus, and extra-skeletal calcifications. Little attention has been paid to low plasma protein concentrations and muscle weakness in these patients. The present study was undertaken to characterize the impact of subtotal parathyroidectomy for chronic hemodialysis on body composition, muscle strength, plasma proteins, quality of life, and long-term clinical course.

METHODS

We performed a prospective observational before-after assessment study of consecutive chronic hemodialysis patients referred for parathyroidectomy. Patients were investigated at baseline before parathyroidectomy and then at 1 and 6 months after surgery, with the aim to assess changes in metabolic parameters, body composition by bioimpedance, muscle strength, and quality of life (36-items Short Form Health Survey questionnaire). Follow-up was terminated when patients reached 1 of the 3 pre-defined end points: recurrence of secondary hyperparathyroidism, transplantation, or death.

RESULTS

A group of 23 patients on hemodialysis were included. Preoperative handgrip strength was diminished by 52.4 ± 17%. After parathyroidectomy, a drop of immunoreactive parathyroid hormone concentrations (1,153 vs 237 pg/mL; P < .001) was observed together with increases in plasma protein (total: 6.8 vs7.8 g/dL, s-albumin 3.7 vs 4.4 g/dL and prealbumin: 31.7 vs 35.2 mg/dL; P < .001), handgrip strength (18.3 vs 22.9 kg: P = .001) as well as an improvement in physical dimension (32.9 vs 35.6; P = .004) and vitality (32.3 vs 47.1; P = .002) domains of the 36-items Short Form Health Survey questionnaire. After10 years, one-third of the patients had died, one-third of the patients had a recurrence of secondary hyperparathyroidism, and one-third of patients had received a kidney transplant and maintained a normal parathyroid function.

CONCLUSION

Subtotal parathyroidectomy improves protein metabolic markers, muscle strength, and physical performance in chronic hemodialysis patients.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

The role of preoperative ultrasound, contrast-enhanced ultrasound, and 99mTc-MIBI scanning with single-photon emission computed tomography/X-ray computed tomography localization in refractory secondary hyperparathyroidism

OBJECTIVE

The aim of our study was to evaluate the role of preoperative US, CEUS, and 99mTc-MIBI scanning with SPECT/CT in localizing diseased parathyroid glands in cases of refractory secondary hyperparathyroidism (SHPT).

MATERIAL AND METHODS

Using pathological results as the gold standard, we compared the operative findings with the preoperative localization of each modality in 73 nodules and evaluated the accuracy, and sensitivity of each modality and combinations of the four modalities.

RESULTS

The sensitivity of US, CEUS, 99mTc-MIBI and SPECT/CT was 98.59%, 94.37%, 50.70% and 78.87%, respectively. US had the highest sensitivity of the four imaging methods and the diagnostic sensitivity of US and CEUS was superior to that of 99mTc-MIBI (p < 0.001 and p < 0.001) and SPECT/CT (p = 0.001 and p = 0.012). In addition, we found that the sensitivity of the combination of US with CEUS, US with 99mTc-MIBI and/or SPECT/CT, CEUS with 99mTc-MIBI and/or SPECT/CT, US with CEUS and two other imaging modalities (99mTc-MIBI and/or SPECT/CT) was 98.59%, 100%, 95.77%, and 100%, respectively.

CONCLUSIONS

The combination of US with SPECT/CT is the best choice for the comprehensive preoperative localization of glands in refractory SHPT. CEUS can elevate the accuracy of US in differential diagnosis via the interpretation of dynamic microvascular features.

Is dual-phase SPECT/CT with 99mTc-sestamibi better than single-phase SPECT/CT for lesion localization in patients with hyperparathyroidism?

This study aimed to establish an optimal protocol for Tc-sestamibi parathyroid imaging for lesion localization in patients with hyperparathyroidism (HPT).We retrospectively enrolled 35 consecutive patients who underwent dual-phase (at 10 minutes and 120 minutes) Tc-sestamibi parathyroid scintigraphy with single-photon emission computed tomography (SPECT)/computed tomography (CT). Twenty seven patients had primary HPT, and 8 had secondary or tertiary HPT. Three nuclear medicine physicians independently analyzed the parathyroid images for lesion localization at 9 predefined parathyroid locations using the following 4 different image sets blinded to the clinical information:All SPECT or SPECT/CT image sets were analyzed with dual-phase planar images. The image results were compared with the histopathological results after surgery.Dual-phase SPECT/CT showed the highest positive rate of 85.7% in the patient-based analysis and 13.7% in the location-based analysis. Of 35 patients, surgical pathological results were available in 21 (16 adenomas in 16 primary HPTs and 16 hyperplasias in 5 secondary or tertiary HPTs). Dual-phase SPECT/CT showed the sensitivity values of 100% and 84.4% in the patient-based and location-based analysis, respectively, which were the highest sensitivity values among all image sets. In the primary HPT subgroup, dual-phase SPECT/CT showed the highest sensitivity value of 93.8% in the location-based analyses, whereas dual-phase SPECT, early SPECT/CT, and delayed SPECT/CT showed the sensitivity values of 62.5%, 81.3%, and 81.3%, respectively. In the secondary or tertiary HPT subgroup, dual-phase SPECT/CT also showed the highest sensitivity value of 75.0%, whereas early SPECT/CT, delayed SPECT/CT, and dual-phase SPECT showed the sensitivity values of 43.8%, 56.3%, and 68.8%, respectively.Compared with dual-phase SPECT or single-phase SPECT/CT, the dual-phase SPECT/CT imaging protocol for Tc-sestamibi scintigraphy showed the highest positive rate and sensitivity, and was optimal for parathyroid lesion localization.

Subtotal parathyroidectomy versus total parathyroidectomy with autotransplantation for secondary hyperparathyroidism: an updated systematic review and meta-analysis

PURPOSE

The optimal surgical approach of parathyroidectomy for patients with secondary hyperparathyroidism (SHPT) has been controversial. The updated meta-analysis aimed to compare the effectiveness of subtotal parathyroidectomy (SPTX) versus total parathyroidectomy with autotransplantation (TPTX + AT).

METHODS

A thorough systematic search was performed on the databases of PubMed, EMBASE, and Cochrane library to identify eligible studies. Data were extracted and pooled into a meta-analysis. The primary outcomes were the symptomatic improvement, radiological changes, hypocalcemia rate, the requirement for vitamin D analogues, time to recurrence, recurrence, persistence, and reoperation rates of SPTX versus TPTX + AT.

RESULTS

A total of 18 studies with 3656 patients (1864 patients in SPTX and 1792 patients in TPTX + AT group) were included, and 15 studies were included in quantitative synthesis. No significant difference was observed in symptomatic improvement (93.3%, 89.0%; P = 0.99), radiological changes (85.4%, 85.3%; P = 0.91), hypocalcemia rate (16.6%, 18.1%; P = 0.29), persistence rate (6.1%, 2.0%; P = 0.16), time to recurrence (mean difference 1.46; P = 0.87), recurrence rate (9.2%, 7.1%; P = 0.76), and reoperation rate (5.3%, 5.8%; P = 0.66) between SPTX and TPTX + AT groups. Longer operative time (150 vs. 120 min), prolonged in-hospital stay (5.0 vs. 4.1 days), lower 1-month serum calcium level, and higher requirement for vitamin D analogues at 12 months were significantly observed in patients who underwent TPTX + AT compared to SPTX.

CONCLUSIONS

The two surgical approaches were both effective at controlling SHPT in clinical and laboratory terms. However, most of the data shown were not statistically significant. It was acceptable that surgeons chose either SPTX or TPTX + AT for SHPT.

Secondary and Tertiary Hyperparathyroidism: A Narrative Review

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

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

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

Management of Post-transplant Hyperparathyroidism and Bone Disease

Significant advances in immunosuppressive therapies have been made in renal transplantation, leading to increased allograft and patient survival. Despite improvement in overall patient survival, patients continue to require management of persistent post-transplant hyperparathyroidism. Medications that treat persistent hyperparathyroidism include vitamin D, vitamin D analogues, and calcimimetics. Medication side effects such as hypocalcemia or hypercalcemia, and adynamic bone disease, may lead to a decrease in the drugs. When medical management fails to control persistent post-transplant hyperparathyroidism, treatment is a parathyroidectomy. Surgical techniques are not uniform between centers and surgeons. Undergoing the surgery may include a subtotal technique or a technique including total parathyroid gland resection with partial heterotopic gland reimplantation. In addition, there are possible post-surgical complications. The ideal treatment for persistent post-transplant hyperparathyroidism is the treatment and prevention of the condition while patients are being managed for their late-stage chronic kidney disease and end-stage renal disease.

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.

How radical is total parathyroidectomy in patients with renal hyperparathyroidism?

Purpose

Total parathyroidectomy (tPTX) in patients with renal hyperparathyroidism (RHPT) aims at the complete removal of all hyperfunctioning parathyroid tissue. Whenever parathyroidectomy is termed “total,” undetectable postoperative parathyroid hormone (PTH) levels within the first postoperative week are expected. The aim of this study was to evaluate if tPTX is technically possible using a radical surgical procedure.

Methods

In 109 consecutive patients with RHPT (on hemodialysis: n = 50; after kidney grafting n = 59), removal of all visible parathyroid tissue, bilateral thymectomy, bilateral central neck dissection (level VI), and immediate autotransplantation (AT) was performed. Intact PTH (iPTH) levels were measured in the first postoperative week. PTX was classified “total” when iPTH dropped below 10 pg/ml, “subtotal” between 10 and 65 pg/ml, and “insufficient” where levels stayed above 65 pg/ml.

Results

According to the postoperative PTH value, tPTX was achieved in 80 of 109 (73.4%) patients (hemodialysis n = 27, normal kidney function: n = 43, restricted: n = 10). PTX was “subtotal” in 25 patients (22.9%), 19 on hemodialysis, 2 had normal, and 4 had restricted kidney graft function. PTX turned out to be insufficient in four patients (3.7%); all of them were on hemodialysis. Insufficient PTX was not observed in kidney-grafted patients. Postoperative temporary laryngeal nerve morbidity was 1.8% (no permanent paresis).

Conclusions

Although applying a very radical concept in patients with RHPT, PTX was “total” in only 73.4%. Persistence of disease was avoided in 91.7%, and low morbidity was documented. In conclusion, it seems difficult to remove all parathyroid tissue from the neck which has to be considered when choosing the surgical procedure.

Total versus subtotal parathyroidectomy for secondary hyperparathyroidism

BACKGROUND

It remains unclear whether total or subtotal parathyroidectomy for secondary hyperparathyroidism yields the best outcomes. We investigated mortality, cardiovascular events, hip fracture, and recurrent parathyroidectomy after total versus subtotal parathyroidectomy in patients on renal replacement therapy.

METHODS

Using the Swedish Renal Registry, the surgical registry for thyroid and parathyroid surgery, and the National Inpatient Registry, we identified patients who underwent parathyroidectomy between 1991 and 2013. We calculated the risk of outcome after total versus subtotal parathyroidectomy using COX's regression, adjusting for age, sex, cause of renal disease, time with a functioning graft before and after parathyroidectomy, Charlson comorbidity index, year of surgery, prevalent cardiovascular disease, time on dialysis, renal transplantation at parathyroidectomy, and treatment with calcimimetics before parathyroidectomy.

RESULTS

There were 824 patients who underwent parathyroidectomy, 388 total and 436 subtotal. There was no difference in mortality or risk of incident hip fracture between groups. Comparing the subtotal with the total parathyroidectomy, the adjusted hazard ratio (95% confidence interval) for cardiovascular events was 0.43 (0.25-0.72) and for recurrent parathyroidectomy 3.33 (1.33-8.32).

CONCLUSION

There was a higher risk of cardiovascular events in patients after total parathyroidectomy compared with subtotal parathyroidectomy, but a lower risk of recurrent parathyroidectomy.

Treatment strategy of end stage renal disease-related hyperparathyroidism before, during, and after the era of calcimimetics

BACKGROUND

Since 2004, end-stage renal disease related hyperparathyroidism patients are treated mainly with cinacalcet, which ceased to be subsidized through the Australian Pharmaceutical Benefits Scheme in 2015. We aimed to investigate the impact of these changes on the treatment strategy in the Australian end-stage renal disease population.

METHODS

The following groups were formed according to the date of parathyroidectomy: A, before calcimimetics; B, during the era of calcimimetics; and C, after cinacalcet removal by the Australian Pharmaceutical Benefits Scheme. The primary outcome was time from start of dialysis to parathyroidectomy. Regression analysis was used to examine trends in parathyroidectomy rates.

RESULTS

Between 1998 and 2016, 195 parathyroidectomies were performed. Median time to referral was 69 (33-123), 67 (31-110) and 44 (23-102) months for groups A, B, and C, respectively (P = .55). Parathyroidectomy rates increased throughout the years (CI 0.09-1.13, R²=0.27, P = .02). A trend toward a dip in parathyroidectomy rates was seen during the era of cinacalcet (P = .08). Median preoperative parathyroid hormone levels increased significantly (842 [418-1,553] versus 1,040 [564-1,810] versus 1,350 [1,037-1,923] pg/mL, for groups A, B, and C, respectively [P < .01]).

CONCLUSION

Parathyroidectomy rates seem to vary according to the availability of cinacalcet. This change in treatment strategy is accompanied with increased preoperative parathyroid hormone levels, reflecting delayed surgery and increased disease severity.

Parathyroidectomy in the Management of Secondary Hyperparathyroidism

Secondary hyperparathyroidism develops in CKD due to a combination of vitamin D deficiency, hypocalcemia, and hyperphosphatemia, and it exists in nearly all patients at the time of dialysis initiation. There is insufficient data on whether to prefer vitamin D analogs compared with calcimimetics, but the available evidence suggests advantages with combination therapy. Calcium derangements, patient adherence, side effects, and cost limit the use of these agents. When parathyroid hormone level persists >800 pg/ml for >6 months, despite exhaustive medical interventions, monoclonal proliferation with nodular hyperplasia is likely present along with decreased expression of vitamin D and calcium-sensing receptors. Hence, surgical parathyroidectomy should be considered, especially if concomitant disorders exist, such as persistent hypercalcemia or hyperphosphatemia, tissue or vascular calcification including calciphylaxis, and/or worsening osteodystrophy. Parathyroidectomy is associated with 15%-57% greater survival in patients on dialysis, and it also improves hypercalcemia, hyperphosphatemia, tissue calcification, bone mineral density, and health-related quality of life. The parathyroidectomy rate in the United States declined to approximately seven per 1000 dialysis patient-years between 2002 and 2011 despite an increase in average parathyroid hormone levels, reflecting calcimimetics introduction and uncertainty regarding optimal parathyroid hormone targets. Hospitalization rates are 39% higher in the first postoperative year. Hungry bone syndrome occurs in approximately 25% of patients on dialysis, and profound hypocalcemia requires high doses of oral and intravenous calcium along with calcitriol supplementation. Total parathyroidectomy with autotransplantation carries a higher risk of permanent hypocalcemia, whereas risk of hyperparathyroidism recurrence is higher with subtotal parathyroidectomy. Given favorable long-term outcomes from observational parathyroidectomy cohorts, despite surgical risk and postoperative challenges, it is reasonable to consider parathyroidectomy in more patients with medically refractory secondary hyperparathyroidism.

Targeted surgical parathyroidectomy in end-stage renal disease patients and long-term metabolic control: A single-center experience in the current era

BACKGROUND

The long-term results of surgical parathyroidectomy (PTX) in end-stage renal disease (ESRD) patients are less well known in the modern era of newer activated vitamin-D analogs, calcimimetics and intraoperative monitoring of parathyroid hormone (PTH).

METHODS

We performed a retrospective chart review of all ESRD patients undergoing PTX at the University of Mississippi Medical Center between January 2005 and August 2011, with follow-up data as available up to 4 years. All PTXs were performed with intraoperative second-generation PTH monitoring and targeted gland size reduction.

RESULTS

The cohort (N = 37) was relatively young with a mean (±SD) age of 48.4 ± 13.9. 94.6% of the subjects were African American and 59.5% female. Preoperatively, 45.9% received cinacalcet (CNC) at a mean dose of 63.5 ± 20.9 mg. The size of the largest removed glands measured 1.7 ± 0.8 cm and almost all (94.6%) glands had hyperplasia on histology. The mean length of inpatient stay was 5.5 ± 2.4 days. Preoperative calcium/phosphorus measured 9.6 ± 1.2/6.6 ± 1.7 mg/dL with PTH concentrations of 1589 ± 827 pg/mL. Postoperative PTH values measured 145.4 ± 119.2 pg/mL. Preoperative PTH strongly correlated (P < 0.0001) with both alkaline phosphatase (ALP) levels (r: 0.596) and the number of inpatient days (r: 0.545), but not with CNC administration. Independent predictors for the duration of hospitalization were preoperative ALP (beta 0.469; P = 0.001) and age (beta -0.401; P = 0.005) (R² 0.45); for postoperative hypocalcemia, age (beta: -0.321; P = 0.006) and preoperative PTH (beta: 0.431; P = 0.036) were significant in linear regression models with stepwise selection.

CONCLUSION

Gland-sparing PTX achieved acceptable control of ESRD-associated hyperparathyroidism in most patients from a socioeconomically challenged, underserved population of the United States.

Near total parathyroidectomy for the treatment of renal hyperparathyroidism

Background

Different surgical strategies are used to treat medical refractory renal hyperparathyroidism. Our preferred choice in patients with moderate secondary hyperparathyroidism (SHPT) and in patients with low compliance with medical treatment is to leave a very small parathyroid remnant in situ: we name this operation "near total parathyroidectomy" (ntPTX). We report here our results with this technique.

Methods

Retrospective study [2001-2015] of all patients submitted to ntPTX in a single centre.

Results

Forty-seven patients were submitted to ntPTX (32 males) aged 47.3 years. Follow-up time is 8.5 years. Thirty-five patients (74%) are alive, 12 are dead. One patient in this series had a functioning renal transplant at time of ntPTX (tertiary hyperparathyroidism), and other 27 subsequently received a renal transplantation (RTx) after ntPTX (still functioning at last follow-up or at death in 19). Amongst the 35 current survivors, the renal graft is functioning in 16 (45.7%). Parathyroid hormone (PTH) at follow-up was 116.1±135.5 pg/mL and calcium 8.6±0.9 mg/dL. Among patients with a functioning RTx PTH was 83 pg/mL and calcium 8.7 mg/dL. There was no persistent disease, and 3 patients (6.4%) had a relapse of hyperparathyroidism at follow-up.

Conclusions

ntPTX is associated to very satisfying rates of normal parathyroid function and of relapse of hyperparathyroidism (6.4%) at long term, either in case of RTx or of maintenance hemodialysis: the concept of "small amount" remnant represents a valuable choice for patients undergoing PTX with a realistic chance of receiving a RTx.

To assess the effects of parathyroidectomy (TPTX versus TPTX+AT) for Secondary Hyperparathyroidism in chronic renal failure: A Systematic Review and Meta-Analysis

BACKGROUND

Secondary Hyperparathyroidism (SHPT) requiring parathyroidectomy (PTX) occurs more commonly in patients with progressive chronic kidney disease and in those on long-term lithium therapy. Successful PTX often results in a dramatic drop of parathyroid hormone level, relieves the patient from clinical symptoms, and reduces mortality. However, there is an ongoing debate on the optimal surgical treatment of SHPT. Currently, no clinical guidelines or trials have definitely answered the question of whether Total Parathyroidectomy (TPTX) is superior or equal to Total Parathyroidectomy with Autotransplantation (TPTX + AT).

OBJECTIVE

The aims of the study were to compare the efficacy of two different surgical procedures and to develop evidence-based practice guidelines for the treatment of SHPT.

METHODS

Citations were identified in the Medline, Cochrane, EMBASE, and Chinese Biomedical Literature databases through November 2016. The Newcastle-Ottawa Scale (NOS) score was used to assess the methodological quality of the studies included. All data were analyzed using Review Manager 5.3.

RESULTS

A total of nine cohort studies and one Randomized Controlled Trials (RCT), comprising 1283 patients, were identified. The NOS score of all the studies included was 5 or above. Compared with TPTX + AT, patients in the TPTX group had lower rates of "recurrence" (OR = 0.20; 95%CI, 0.11-0.38; P < 0.01), "recurrence or persistence" (OR = 0.18; 95%CI, 0.10-0.33; P < 0.01), "reoperation due to recurrence or persistence" (OR = 0.17; 95%CI, 0.06-0.54; P = 0.002), and shorter "operative time" (WMD = -17.30; 95%CI, -30.53 to -4.06; P < 0.05), except for a higher risk of "hypoparathyroidism" (OR = 2.97; 95%CI, 1.09-8.08; P = 0.01). However, none of the patients had developed permanent hypocalcemia or adynamic bone disease. No significant difference was found for "symptomatic improvement", "complications", "drug requirements", and "hospital stay" (P > 0.05).

CONCLUSION

The findings indicate that TPTX is superior to TPTX + AT, while referring to the rate of recurrent SHPT. However, this conclusion needs to be tested in large-scale confirmatory trials. TPTX seems to be a feasible alternative therapeutic option for the surgical treatment of refractory SHPT.

An Evidence-Based Approach to Conducting Systematic Reviews on CKD

With the growing need to integrate best evidence to inform clinical care, systematic reviews have continued to flourish. Although this type of review is integral to the synthesis of evidence-based information, systematic reviews are often conducted omitting well-established processes that ensure the validity and replicability of the study; elements of which are integral based on standards developed by the Cochrane Collaboration and the National Academy of Medicine. This review article will share best practices associated with conducting systematic reviews on the topic of CKD using an 8-step process and an evidence-based approach to retrieving and abstracting data. Optimal methods for conducting systematic review searching will be described, including development of appropriate search strategies and utilization of varied resources including databases, grey literature, primary journals, and handsearching. Processes and tools to improve research teams' coordination and efficiency, including integration of systematic review protocols and sophisticated software to streamline data management, will be investigated. In addition to recommended strategies for surveying and synthesizing CKD literature, techniques for maneuvering the complex field of Nephrology will also be explored.