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

Diagnostic value of contrast-enhanced ultrasound in judging the survival of graft after heteroautoplasty for secondary hyperparathyroidism

BACKGROUND

Secondary hyperparathyroidism (SHPT) is one of the common complications of end-stage renal disease-uremia, and is mainly manifested as parathyroid hyperplasia and abnormal secretion of parathyroid hormone (PTH).

OBJECTIVE

To investigate the value and advantages of contrast-enhanced ultrasound (CEUS) in evaluating the survival of autografts after parathyroidectomy + parathyroid autotransplantation.

METHODS

In this study, 125 patients with renal failure due to polycystic kidney disease, chronic nephritis, diabetic nephropathy, lupus nephritis, and atherosclerotic nephropathy were enrolled as the participants and each of them had 4 secondary hyperactive parathyroid glands and underwent parathyroid autotransplantation. One parathyroid gland was taken from each patient and equally divided into 4 parts and placed in the subcutaneous fat of one forearm for transplantation. CEUS was performed 14 days after the transplantation to observe the micro blood supply of the graft and assess the survival and secretory function of the transplanted parathyroid. The grafts were divided into the partial survival group and the total survival group based on the enhancement characteristics. The survival of the grafts was determined by comparing the parathyroid hormone level in bilateral elbow cephalic veins 1 month after surgery.

RESULTS

Among the 125 patients, 112 had linear or punctate enhancement of 2-4 parathyroid glands 14 days after surgery, and 13 patients had linear or punctate enhancement of 0-1 parathyroid gland. There were statistically significant differences in the perfusion pattern, enhancement uniformity, and parathyroid hormone levels in the cephalic veins at the elbow on both the graft and non-graft sides among all groups (P< 0.05).

CONCLUSION

Compared to the detection of the difference in the parathyroid hormone level in the cephalic vein of bilateral elbows 1 month after surgery, CEUS can reflect the parathyroid survival after transplantation more quickly and accurately 2 weeks later, and provide a more rapid and agile non-invasive clinical diagnosis method.

Outcomes of subtotal parathyroidectomy for renal hyperparathyroidism

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Parathyroid Carcinoma in a Patient With Secondary Hyperparathyroidism and Thyroid Hemiagenesis: A Case Report and Review of the Literature

Parathyroid carcinoma is a rare endocrine tumor. Parathyroid carcinoma in patients with secondary hyperparathyroidism due to chronic kidney disease is also rare. In addition, thyroid hemiagenesis is a rare congenital anomaly. We report an extremely rare case of parathyroid carcinoma in a patient with secondary hyperparathyroidism and thyroid hemiagenesis. We also present a review of the literature of this rare entity. We also discuss the surgical procedure performed for this patient. Our review of the literature found 34 case reports of parathyroid carcinoma in patients undergoing dialysis due to chronic renal failure; 14 reports of thyroid hemiagenesis with parathyroid disease; and no previous reports of thyroid hemiagenesis with secondary hyperparathyroidism and parathyroid carcinoma. Although surgical treatment of parathyroid carcinoma requires combined resection with the thyroid, peritracheal dissection with total parathyroidectomy, and monitoring intact parathyroid hormone as a tumor marker, our procedure preserved the patient's thyroid function. There has been no evidence of recurrence for over 8 years.

Advantages of total parathyroidectomy in patients with secondary hyperparathyroidism induced by end stage renal disease

Introduction

Secondary hyperparathyroidism, as a result of chronic kidney disease could be treated medically or surgically. When pharmacotherapy fails, patients undergo surgery - parathyroidectomy, the curative treatment of secondary hyperparathyroidism (SHPT). There are currently 3 accepted surgical techniques, each with supporters or opponents - total parathyroidectomy, subtotal parathyroidectomy and parathyroidectomy with immediate autotransplantation.

Methods

In this paper we described our experience on a series of 160 consecutive patients diagnosed with secondary hyperparathyroidism who underwent surgery, in 27 cases it was totalization of the intervention (patients with previously performed subtotal parathyroidectomy or with supernumerary glands and SHPT recurrence). We routinely perform total parathyroidectomy, the method that we believe offers the best results.

Results

The group of patients was studied according to demographic criteria, paraclinical balance, clinical symptomatology, pre- and postoperative iPTH (intact parathormone) values, SHPT recurrence, number of reinterventions. In 31 cases we found gland ectopy and in 15 cases we discovered supernumerary parathyroids. A percentage of 96.24% of patients with total parathyroidectomy did not show recurrence.

Discussions

After analyzing the obtained results, our conclusion was that total parathyroidectomy is the intervention of choice for patients suffering from secondary hyperparathyroidism when pharmacotherapy fails in order to prevent recurrence of the disease and to correct the metabolic parameters.

Efficacy and safety of total parathyroidectomy with autotransplantation vs. subtotal parathyroidectomy for secondary hyperparathyroidism: A retrospective study

Background

No consensus has been reached on the best surgical approach for secondary hyperparathyroidism (SHPT). We evaluated the short-term and long-term efficacy and safety of total parathyroidectomy with autotransplantation (TPTX + AT) and subtotal parathyroidectomy (SPTX).

Methods

We retrospectively analyzed the data of 140 patients undergoing TPTX + AT and 64 undergoing SPTX between 2010 and 2021 in Second Affiliated Hospital of Soochow University, and carried out follow-up. We compared the differences in symptoms, serological examinations, complications and mortality between the two methods, and explored the independent risk factors of secondary hyperparathyroidism recurrence.

Results

In short time after surgery, serum intact parathyroid hormone and calcium level was lower in TPTX + AT group than that in SPTX group (both P < 0.05). Severe hypocalcemia was more common in TPTX group (P = 0.003). The recurrent rate was 17.1% for TPTX + AT and 34.4% for SPTX (P = 0.006). There was no statistical difference in all-cause mortality, cardiovascular events, cardiovascular mortality between the two methods. Higher preoperative serum phosphorus level (HR: 1.929 95% CI 1.045-3.563, P = 0.011) and the SPTX surgical method (HR: 2.309, 95% CI 1.276-4.176, P = 0.006) were found to be independent risk factors for SHPT recurrence.

Conclusions

Compared with SPTX, TPTX + AT is more effective in reducing the recurrent risk of SHPT without increasing the risk of all-cause mortality and cardiovascular events.

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.

18F-Fluorocholine PET/CT Compared with Current Imaging Procedures for Preoperative Localization of Hyperfunctioning Parathyroids in Patients with Chronic Kidney Disease

Hyperparathyroidism (HPT) in patients with chronic kidney disease (CKD) includes secondary (sHPT) and tertiary hyperparathyroidism (tHPT). Considering that the role of preoperative imaging in the clinical setting is controversial, in the present study we have retrospectively compared pre-surgical diagnostic performances of ¹⁸F-Fluorocholine (¹⁸F-FCH) PET/CT, cervical ultrasonography (US), parathyroid scintigraphy, and 4D-CT in a group of 30 patients with CKD and HPT (18/12 sHPT/tHPT), 21 CKD G5 including 18 in dialysis, and 9 kidney transplant recipients. All patients underwent ¹⁸F-FCH, and 22 had cervical US, 12 had parathyroid scintigraphy, and 11 had 4D-CT. Histopathology was the gold standard. Seventy-four parathyroids were removed: 65 hyperplasia, 6 adenomas, and 3 normal glands. In the whole population, in a per gland analysis, ¹⁸F-FCH PET/CT was significantly more sensitive and accurate (72%, 71%) than neck US (25%, 43%), parathyroid scintigraphy (35%, 47%), and 4D-CT (40%, 47%). The specificity of ¹⁸F-FCH PET/CT (69%) was lower than that of neck US (95%) and parathyroid scintigraphy (90%), without, however, achieving significance. ¹⁸F-FCH PET/CT was more accurate than all other diagnostic techniques when sHPT and tHPT patients were considered separately. ¹⁸F-FCH PET/CT sensitivity was significantly higher in tHPT (88%) than in sHPT (66%). Three ectopic hyperfunctioning glands (in three different patients) were all detected by ¹⁸F-FCH PET/CT, two by parathyroid scintigraphy, and none by cervical US and 4D-CT. Our study confirms that ¹⁸F-FCH PET/CT is an effective preoperative imaging option in patients with CKD and HPT. These findings may be of greater importance in patients with tHPT (who could benefit from minimally invasive parathyroidectomy) than in patients with sHPT, who often undergo bilateral cervicotomy. In these cases, preoperative ¹⁸F-FCH PET/CT may be helpful in locating ectopic glands and may guide the surgical choice for gland preservation.

Comparative Effectiveness of MRI, 4D-CT and Ultrasonography in Patients with Secondary Hyperparathyroidism

Objective

Accurate preoperative localization of abnormal parathyroid glands is crucial for successful surgical management of secondary hyperparathyroidism (SHPT). This study was conducted to compare the effectiveness of preoperative MRI, 4D-CT, and ultrasonography (US) in localizing parathyroid lesions in patients with SHPT.

Methods

We performed a retrospective review of prospectively collected data from a tertiary-care hospital and identified 52 patients who received preoperative MRI and/or 4D-CT and/or US and/or ^99mTc-MIBI and subsequently underwent surgery for SHPT between May 2013 and March 2020. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of each imaging modality to accurately detect enlarged parathyroid glands were determined using histopathology as the criterion standard with confirmation using the postoperative biochemical response.

Results

A total of 198 lesions were identified intraoperatively among the 52 patients included in this investigation. MRI outperformed 4D-CT and US in terms of sensitivity (P < 0.01), specificity (P = 0.455), PPV (P = 0.753), and NPV (P = 0.185). The sensitivity and specificity for MRI, 4D-CT, and US were 90.91%, 88.95%, and 66.23% and 58.33%, 63.64%, and 50.00%, respectively. The PPV of combined MRI and 4D-CT (96.52%) was the highest among the combined 2 modalities. The smallest diameter of the parathyroid gland precisely localized by MRI was 8×3 mm, 5×5 mm by 4D-CT, and 5×3 mm by US.

Conclusion

MRI has superior diagnostic performance compared with other modalities as a first-line imaging study for patients undergoing renal hyperparathyroidism, especially for ectopic or small parathyroid lesions. We suggest performing US first for diagnosis and then MRI to make a precise localization, and MRI proved to be very helpful in achieving a high success rate in the surgical treatment of renal hyperparathyroidism in our own experience.

Recurrent renal secondary hyperparathyroidism caused by supernumerary mediastinal parathyroid gland and parathyromatosis: A case report

Background

Surgical parathyroidectomy (PTX) is necessary for patients with severe and progressive secondary hyperparathyroidism (SHPT) refractory to medical treatment. Recurrence of SHPT after PTX is a serious clinical problem. Both supernumerary mediastinal parathyroid gland and parathyromatosis are the rare causes of recurrent renal SHPT. We report a rare case of recurrent renal SHPT due to supernumerary mediastinal parathyroid gland and parathyromatosis.

Case presentation

A 53-year-old man underwent total parathyroidectomy with autotransplantation due to the drug-refractory SHPT 17 years ago. In the last 11 months, the patient experienced symptoms including bone pain and skin itch, and the serum intact parathyroid hormone (iPTH) level elevated to 1,587 pg/ml. Ultrasound detected two hypoechoic lesions located at the dorsal area of right lobe of the thyroid gland, and both lesions presented as characteristics of hyperparathyroidism in contrast-enhanced ultrasound. ^99mTc-MIBI/SPECT detected a nodule in the mediastinum. A reoperation involved a cervicotomy for excising parathyromatosis lesions and the surrounding tissue and a thoracoscopic surgery for resecting a mediastinal parathyroid gland. According to a histological examination, two lesions behind the right thyroid lobe and one lesion in the central region had been defined as parathyromatosis. A nodule in the mediastinum was consistent with hyperplastic parathyroid. The patient remained well for 10 months with alleviated symptoms and stabilized iPTH levels in the range of 123-201 pg/ml.

Conclusion

Although rare, recurrent SHPT may be caused by a coexistence of both supernumerary parathyroid glands and parathyromatosis, which should receive more attention. The combination of imaging modalities is important for reoperative locations of parathyroid lesions. To successfully treat parathyromatosis, all the lesions and the surrounding tissue must be excised. Thoracoscopic surgery is a reliable and safe approach for the resection of ectopic mediastinal parathyroid glands.

A preoperative parathyroid scan is important for the total removal of the transplanted parathyroid tissue in recurrent secondary hyperthyroidism: A case report and literature review

RATIONALE

Secondary hyperparathyroidism was one of mineral and bone disorders owing to chronic kidney disease. Patients who suffer from secondary hyperparathyroidism would receive medical treatment or parathyroidectomy with or without autotransplantation (AT). However, some patients receiving parathyroidectomy with AT have recurrent hyperparathyroidism, which impacts their lives. Patients with recurrent hyperparathyroidism may present persistent hypercalcemia and hyperphosphatemia, which would cause cardiovascular disease, like atherosclerosis.

PATIENT CONCERNS

A 63-year-old female of Asian descent with chronic kidney disease who suffered from recurrent hyperparathyroidism for twice. The patient underwent parathyroidectomy with AT in the left thigh when secondary hyperparathyroidism happened. After 3 months, recurrent hyperparathyroidism happened.

DIAGNOSIS

The patient was diagnosed with recurrent hyperparathyroidism due to chronic kidney disease with hyperparathyroidism status post parathyroidectomy with AT in the left thigh. Our patient also suffered from mineral and bone disorder.

INTERVENTION

Two parathyroid adenoma in the left thigh were found. However, one of them was too small to found in the operation. Therefore, autograftectomy of the large one was performed. However, hyperparathyroidism happened again. This time, the autograftectomy was performed under dual phase Tc-99m MIBI (99m Tc-methoxy isobutyl isonitrile) parathyroid scintigraphy and it succeeded.

OUTCOMES

After secondary autograftectomy, the value of intact parathyroid hormone was surveyed immediately and dropped by two-third followed by gradual reduction in the following weeks. The calcemia and phosphatemia were back to normal gradually.

LESSONS

In our case, importance of scintigraphy in the parathyroidectomy was confirmed.

[Evolution of the incidence and results at 12 months of parathyroidectomy: 40 years of experience in a dialysis center with two successive surgical departments]

INTRODUCTION

Secondary hyperparathyroidism remains the main complication of mineral and bone metabolism in patients with chronic kidney disease. In case of resistance to medical treatment (native and active vitamin D, calcium and calcimimetics), surgical parathyroidectomy is indicated. The aim of this retrospective study is to show the evolution of the incidence and results of surgical parathyroidectomy in our center between 1980 and 2020 as patient characteristics, diagnostic and therapeutic strategies have changed.

PATIENTS AND METHODS

We collected data from dialysis patients who had a first surgical parathyroidectomy between 2000 and 2020 (period 2) in the same surgical department and compared them with historical data between 1980 and 1999 (period 1) operated in one other center.

RESULTS

In period 1, 53 surgical parathyroidectomy were performed (2.78/year, 0 to 5, 8.5/1000 patients-year) vs.56 surgical parathyroidectomy in period 2 (2.8/year, 0 to 9, 8/1000 patients-year). The patients of the 2 periods were comparable except for the higher dialysis vintage in period 1 (149±170 vs.89±94 months; P=0.02). In comparison with dialysis patients not requiring surgical parathyroidectomy during the same period, patients who had surgical parathyroidectomy were younger, had higher dialysis vintage and lower diabetes prevalence, but more frequently carriers of glomerulopathy or polycystosis. Systematically performed in period 2, cervical ultrasound identified at least one visible gland in 78.6% of cases while the scintigraphy, performed only in 66% of cases, found at least one gland in 81% of cases. Twelve months after surgery, PTH > 300 pg/mL (marker of secondary hyperparathyroidism recurrence or surgery failure) was present in 30% of patients in period 1 vs. 5.3% in period 2. Hypoparathyroidism was also more frequently observed in period 2 (35.7 vs. 18.8%). Surgical complications were also higher in period 1.

CONCLUSION

Despite therapeutic and strategic advances, severe secondary hyperparathyroidism is still as common as ever. It is favored by excessively high PTH targets, by suboptimal prevention before dialysis and poor tolerance of calcimimetics. The surgical parathyroidectomy is effective and safe in the hands of a specialized team with an ultrasound and scintigraphic preoperative assessment.

Effect of total parathyroidectomy in patients with secondary hyperparathyroidism: a retrospective study

Purpose

To investigate the therapeutic efficacy, feasibility, and safety of total parathyroidectomy (tPTX) in the treatment of secondary hyperparathyroidism (SHPT).

Methods

The clinical data of 34 SHPT patients admitted to the Department of Nephrology, Yuxi People’s Hospital, from January 2018 to January 2021 who had received tPTX, were retrospectively analyzed. The indications for tPTX were severe SHPT that did not respond to medical treatment and was ineligible for kidney transplantation. tPTX without autotransplantation was adopted to compare the level of symptom relief and changes in serum intact parathyroid hormone (iPTH), blood calcium, and blood phosphorus pre- and postoperatively.

Results

In 34 patients, 142 parathyroid glands were removed, including 21 ectopic parathyroid glands (14.78%). Six patients (17.64%, 6/34) had supernumerary parathyroid glands. At 6 h postoperatively, arthralgia and bone pain were significantly reduced to almost zero in 94.12% (32/34) of patients. At 24 h postoperatively, relief of bone pain and improvement of limb movement were observed in 100% (34/34) of patients, and pruritus almost disappeared in 86.36% (19/22) of patients. There were significant differences in iPTH (χ2 = 134.93, P < 0.05), calcium (χ2 = 23.02, P < 0.05), and phosphorus (χ2 = 102.11, P < 0.05) levels preoperatively and 40 min, 24 h, 1 week, half a year, and last available (> 1 year) postoperatively.

The patients were followed up for 15–47 months (median 33 months). Hypoparathyroidism was observed in three patients, who underwent neck dissection or partial thymotomy concurrently for different reasons. No intractable hypocalcemia or adynamic bone disease occurred during the follow-up period.

Conclusion

In SHPT patients who were ineligible for renal transplantation, tPTX was effective, safe, and reliable, with a low recurrence rate. However, when tPTX was performed alone without autologous transplantation, bilateral neck exploration was sufficient, and central neck dissection and thymic resection were inadvisable.

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

OBJECTIVE

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A predictive risk score to diagnose hypocalcemia after parathyroidectomy in patients with secondary hyperparathyroidism: a 22-year retrospective cohort study

Hypocalcemia is a common complication found in patients with secondary hyperparathyroidism (SHPT) who undergo parathyroidectomy. This study aimed to construct a predictive risk score for the occurrence of hypocalcemia after parathyroidectomy in patients with SHPT who underwent chronic renal replacement therapy (RRT). This 22-year retrospective cohort study enrolled 179 patients with SHPT who had their first parathyroidectomy. Eighty-two percent of patients developed hypocalcemia within 16.9 (95% CI 14.5–19.5) h after parathyroidectomy. This study demonstrated four factors as independent risk factors for post-parathyroidectomy hypocalcemia, including duration of RRT, preoperative serum phosphate, preoperative serum alkaline phosphatase (ALP) and mean difference of serum intact parathyroid hormone (iPTH). By using logistic regression analysis, this study demonstrated cut-off points for these four risk factors for the diagnosis of hypocalcemia after parathyroidectomy: 5 years for the duration of RRT, 5 mg/dL for serum phosphate, 387 U/L for serum ALP, and 97% for the mean difference of serum iPTH. Finally, the predictive risk score was constructed by assigning a score of one to each factor. With a total score of at least 2, the proposed predictive risk score has an AuROC of 0.755 with a sensitivity of 78.2%, a specificity of 71.4%, and an accuracy of 76.9%.

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.

Hyperkalemia Following Parathyroidectomy in Patients with Renal Hyperparathyroidism-New Thresholds for Urgent Perioperative Dialysis

Parathyroidectomy (PTX) is a mainstay of treating secondary hyperparathyroidism (SHPT) in patients with kidney failure in order to reduce the incidence of cardiovascular events (CVE), increase overall survival and improve quality of life. Perioperative hyperkalemia may lead to devastating cardiac complications. Distinct preoperative thresholds for serum potassium levels (SPL) were defined, but neither their usefulness nor consecutive risks are understood. This study compared the results and efficacy of different clinical procedures in preventing or treating perioperative hyperkalemia, including postoperative urgent hemodialysis (UHD). Methods: Patients from Charité-Universitätsmedizin Berlin and Rheinland Klinikum Lukaskrankenhaus, Neuss, undergoing PTX due to SHPT between 2008 and 2018 were analyzed retrospectively with regard to demographic parameters, surgery specific conditions and perioperative laboratory results. Comparisons of patient values from both centers with focus on perioperative hyperkalemia and the need for UHD were performed. Results: A total of 251 patients undergoing PTX for SHPT were included (Neuss: n = 121 (48%); Berlin: n = 130 (52%)). Perioperative hyperkalemia (SPL ≥ 5.5 mmol/L) was noted in 134 patients (53%). UHD on the day of surgery was performed especially in patients with intraoperative hyperkalemia, in females (n = 40 (16%) vs. n = 27 (11%); p = 0.023), in obese patients (n = 27 (40%) vs. n = 50 (28%), p = 0.040) and more often in patients treated in Neuss (n = 42 (35%) vs. 25 (19%); p = 0.006). For patients treated in Neuss, the intraoperative hyperkalemia cut-off level above 5.75 mmol/L was the most predictive factor for UHD (n = 30 (71%) vs. n = 8 (10%); p < 0.001). Concerning secondary effects of hyperkalemia or UHD, no patient died within the postoperative period, and only three patients suffered from acute CVE, with SPL > 5.5 mmol/L measured in only one patient. Conclusion: Perioperative values could not predict postoperative hyperkalemia with the need for UHD. Previously defined cut-off levels for SPL should be reconsidered, especially for patients undergoing PTX. Early postoperative dialysis in patients with postoperative hyperkalemia can be performed with a low risk for complications and may be indicated for all patients with increased perioperative SPL.

[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.

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.

The role of 99mTc-MIBI SPECT/CT in patients with secondary hyperparathyroidism: comparison with 99mTc-MIBI planar scintigraphy and ultrasonography

BACKGROUND

This study aimed to compare the sensitivity of ^99mTc-MIBI SPECT/CT, ^99mTc-MIBI planar scintigraphy and ultrasonography (US) in patients with secondary hyperparathyroidism (SHPT), and to explore the factors that affect the sensitivity of ^99mTc-MIBI SPECT/CT.

METHODS

In this retrospective study, forty-six patients with SHPT who underwent ^99mTc-MIBI planar scintigraphy, ^99mTc-MIBI SPECT/CT and US were enrolled. They underwent surgery within 1 month. We compared the sensitivity of the different imaging methods based on the lesions according to the pathological results. The parathyroid lesions on ^99mTc-MIBI SPECT/CT images were divided into missed diagnosis group (MDG) and non-missed diagnosis group (NMDG). We compared the lesion to background ratio (LBR), maximum diameter, volume, the mean CT Hounsfield unit values (CT_mean) and location of lesions between MDG and NMDG.

RESULTS

The sensitivity of ^99mTc-MIBI SPECT/CT, ^99mTc-MIBI planar scintigraphy and US were 70.30% versus 48.48% versus 61.82%, respectively. The sensitivity of ^99mTc-MIBI SPECT/CT combined US was 79.39%, which was higher than ^99mTc-MIBI SPECT/CT with significant difference (P = 0.000). On ^99mTc-MIBI SPECT/CT images, the LBR, maximum diameter and volume of lesions in MDG was smaller than those in NMDG with significant difference (P < 0.001). The average LBR, maximum diameter and volume of lesions in MDG and NMDG were 3.42 ± 1.28, 9.32 ± 2.69 mm, 208.51 ± 163.22 mm³ versus 6.75 ± 5.08, 15.03 ± 4.94 mm and 863.85 ± 1216.0 mm³, respectively.

CONCLUSIONS

^99mTc-MIBI SPECT/CT exhibited the highest sensitivity among the three methods. When ^99mTc-MIBI SPECT/CT combined with US, the sensitivity can be further improved. Lesions with lower MIBI uptake and smaller lesions on ^99mTc-MIBI SPECT/CT images were easily missed.

Application of carbon nanoparticles in localization of parathyroid glands during total parathyroidectomy for secondary hyperparathyroidism

BACKGROUND

Intraoperative imaging is used to address the challenges of parathyroidectomy, but no standard modality has been established. This study aimed to assess whether carbon nanoparticle injection is useful in localizing parathyroid glands (PGs) during parathyroidectomy.

METHODS

Patients who underwent total parathyroidectomy (TPTX) between September 2015 and November 2018 were included. The operative duration and intact parathyroid hormones (iPTH) were analyzed.

RESULTS

A total of 61 patients were included; of these, 32 with carbon nanoparticle injection (TPTX + CN group) and 29 without (TPTX group). The operative duration in the TPTX + CN group was significantly shorter (90.6 ± 21.2 vs 101.4 ± 19.4 min, P = 0.042), which is more apparent in those with normal sized PGs. For those with four enlarged PGs, iPTH levels on 1 day and 1 year postoperatively were significantly lower in the TPTX + CN group (P = 0.032 and P = 0.036, respectively).

CONCLUSION

Carbon nanoparticles are useful in the identification normal sized PGs and complete resection of enlarged PGs.

Network meta-analysis of surgical treatment for secondary hyperparathyroidism

BACKGROUND

Main surgical treatments for secondary hyperparathyroidism (SHPT) include subtotal parathyroidectomy (sPTX), total parathyroidectomy with autotransplantation (tPTX+AT), and total parathyroidectomy (tPTX); however, determining the best treatment is debatable. We conducted a network meta-analysis (NMA) comparing three treatments in terms of postoperative hypocalcemia (or hypoparathyroidism), postoperative recurrence, and reoperation.

METHODS

We searched PubMed, Medline, the Cochrane Library, and Embase for relevant research from inception to July 30, 2019. We performed our Bayesian NMA using R 3.51 software to assess odds ratios (OR) and 95% confidence intervals (CI). Network and forest plots displayed study outputs. Potential publication bias was assessed with funnel plots using software Stata/MP 13.0.

RESULTS

Twenty-six articles comprising 5063 patients were included in our NMA, which showed that postoperative hypocalcemia (or hypoparathyroidism) occurred more frequently in tPTX than in sPTX (OR = 3.50, 95% CI 1.10-11.0) or tPTX+AT patients (OR = 1.80, 95% CI 0.66-5.20). Regarding postoperative hypocalcemia (or hypoparathyroidism), there was no significant difference between sPTX and tPTX+AT (OR = 0.53, 95% CI 0.24-1.10). As for recurrence rates, statistically significant differences were observed between sPTX and tPTX (OR = 25.0, 95% CI 5.1-260), tPTX+AT and tPTX (OR = 20.0, 95% CI 4.2-200), and sPTX and tPTX+AT (OR = 1.30, 95% CI 0.65-2.50). Regarding reoperation rates, sPTX experienced higher incidence compared with tPTX+AT (OR = 1.20, 95% CI 0.53-2.70) or tPTX patients (OR = 2.70, 95% CI 1.20-14.00).

CONCLUSIONS

TPTX+AT is recommended as the most efficient and safe surgical SHPT treatment with minimal adverse effects. Large-scale randomized controlled trials are recommended to confirm the NMA results.

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.

Parathyroid carcinoma arising from auto-transplanted parathyroid tissue after Total Parathyroidectomy in chronic kidney disease patient: a case report

BACKGROUND

Secondary hyperparathyroidism is a common complication in patients with chronic kidney disease that requires vigilant treatment due to its high mortality rate. Pharmacologic therapy is recommended as an initial treatment; if there is no response, a total parathyroidectomy is performed. In some cases, surgery is accompanied by auto-transplantation of parathyroid tissue.

CASE PRESENTATION

The patient was diagnosed with chronic kidney disease and received a kidney transplant. However, due to rejection of the transplanted kidney, medical nephrectomy was carried out and routine hemodialysis was initiated and observed. At this time, secondary hyperparathyroidism with elevated parathyroid hormone and hyperphosphatemia developed and pharmacologic treatment was applied. However, there was no response to pharmacologic treatment; therefore, total parathyroidectomy with auto-transplantation was performed. Eight years after surgery, a growing mass was observed in the transplantation site, accompanied by an elevation of parathyroid hormone. A complete resection of the mass was performed, and the patient was diagnosed with parathyroid carcinoma. Additional adjuvant radiation therapy was ordered, and the patient is being monitored.

CONCLUSIONS

This is a rare but remarkable case of parathyroid carcinoma arising from auto-transplanted parathyroid tissue after total parathyroidectomy in a patient with secondary hyperparathyroidism. We suggest caution should be taken when choosing to auto- transplant parathyroid tissue and that careful postoperative observation should be performed.

Three Patients with Lithium-Associated Hyperparathyroidism: Literature Review Regarding Medical and Surgical Management

Lithium (Li) carbonate has been established as a mood stabilizer and an efficacious treatment for bipolar disorder since its discovery by Dr. John Cade in 1948. Li interacts significantly with organ systems and endocrine pathways. One of the most challenging side effects of Li to manage is its effect on the parathyroid glands. Dysregulation of parathyroid signaling due to Li results in hypercalcemia due to increased vitamin D₃ generation, increased calcium absorption from the gut, and bone resorption, occasionally resulting in concomitant hypercalciuria. However, hypercalciuria is not a definitive feature for hyperparathyroidism, and normal calcium excretion might be seen in these patients. Hypercalcemia may also result from volume contraction and decreased renal clearance, which are commonly seen in these patients. Anatomically the parathyroid abnormalities can present as single or multiglandular disease. We report 3 cases where the patients developed multiple side effects of Li therapy as well as hypercalcemia due to hyperparathyroidism. The literature is reviewed with regard to medical and surgical management of Li-associated hyperparathyroidism in the context of these 3 presented cases.

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.

Can we predict who will develop postoperative hyperkalaemia after parathyroidectomy in dialysis patients with secondary hyperparathyroidism?

BACKGROUND

Hyperkalaemia occurs frequently in many maintenance haemodialysis (MHD) patients after parathyroidectomy (PTX) with secondary hyperparathyroidism (SHPT). However, the clinical risk factors that predict postoperative hyperkalaemia are uncertain.

METHODS

This retrospective cohort study included 90 maintenance haemodialysis patients aged ≥18 years who underwent PTX between April 2011 and April 2016 at Aerospace Center Hospital (Peking University Aerospace School of Clinical Medicine). Pre- and post-PTX surgery venous samples were measured in quadruplicate. We examined univariate associations with demographics, dialysis characteristics, laboratory values and medications. Hyperkalaemia was defined as serum potassium >5.3 mmol/L.

RESULTS

Out of nighty patients, twenty-two (24.4%) developed postoperative hyperkalaemia, of whom sixteen (18.1%) developed hyperkalaemia on postoperative day 3. The univariate analysis showed that weight, dialysis duration, preoperative serum potassium, alkaline phosphate, triglyceride, and postoperative alkaline phosphate were independently associated with hyperkalaemia after parathyroidectomy. The univariate logistic regression model showed that preoperative serum potassium was the only independent factor that could predict hyperkalaemia after parathyroidectomy (odds ratio, 1.59; 95% confidence interval, 1.24-2.05). The optimal cut-off for pre-operative K was 3.9 mmol/L according to the receiver operating characteristic (ROC) curve. A higher incidence of postoperative hyperkalaemia was found in male and younger patients, but the difference was not statistically significant (p>0.05).

CONCLUSIONS

Pre-operative serum potassium less than 3.9 mmol/L was associated with less hyperkalaemia post-operatively in end-stage renal disease (ESRD) patients undergoing PTX.

Anatomical distribution and number of parathyroid glands, and parathyroid function, after total parathyroidectomy and bilateral cervical thymectomy

The normal distribution of parathyroid glands is well documented. However, this study aims to evaluate the efficacy of total parathyroidectomy (TPTx) and bilateral cervical thymectomy (BCTx) for the treatment of secondary hyperparathyroidism (SHPT) through identifying the location of parathyroid glands with attention to the pattern and frequency of orthotopic and ectopic glands.Between 2013 and 2018, sixty chronic hemodialysis patients with medically refractory SHPT underwent TPTx & BCTx. The adequacy of the operation was defined by the pathological confirmation of at least 4 parathyroid glands, accompanied by an intact parathormone (iPTH) value of <60 pg/mL on postoperative day 1(POD1). Based on their anatomical localizations, four distinct sites were identified for both the upper (Zone I-IV) and lower parathyroid glands (Zone V-VIII).The mean follow-up was 15.2 ± 14.6 months. The mean iPTH values on POD1 were normal in 50 patients, with an average of 11.7 ± 14.4 pg/mL. Ten patients (16.6%) had persistent HPT after the operation, three of whom underwent complementary parathyroidectomy. The surgical success rates after first and second operations were both 83.3%. A total of 235 parathyroid glands were detected. Ninety-two percent of the upper parathyroids were located in Zones I and II. However, almost 28% of the lower parathyroids were ectopic and located in Zones VII and VIII.At least one fourth of the lower parathyroids are ectopic; for this reason, Zones VII and VIII require careful investigation during surgery. For upper parathyroids not found in Zone I-III, total thyroidectomy on the same side is recommended.

Unusual recurrent renal secondary hyperparathyroidism caused by hyperplastic autograft with supernumerary parathyroid adenoma: A case report

RATIONALE

Secondary hyperparathyroidism (SHPT) is often complicated with chronic renal failure. Though the total parathyroidectomy (TPTX) with forearm autotransplantation (FAT) has been commonly used to treatment refractory renal SHPT, the recurrence of SHPT is not infrequent, resulting from hyperplastic autograft, remnant parathyroid tissues, and supernumerary parathyroid gland (SPG).

PATIENT CONCERNS

A 67-year-old man undergoing TPTX+FAT 4 years previously for renal SHPT, who received regular hemodialysis with active vitamin D supplements of Rocaltrol treatment postoperatively, was admitted to our hospital with progressively elevated serum intact parathyroid hormone (iPTH) from 176 to 1266 pg/mL for 8 months and bilateral ankle joints pain for 1 month. Tc-sestamibi dual-phase imaging with single positron emission tomography (SPECT)/computed tomography (CT) revealed a nodule in suprasternal fossa, besides a nodule in autografted site, accompanied with intense radioactivity.

DIAGNOSIS

Recurrent SHPT was easily diagnosed based on previous medical history, painful joints, increased serum iPTH level and positive findings of Tc-sestamibi imaging. Routine postoperative pathology showed that the nodules were consistent with an adenomatoid hyperplasic autograft and a supernumerary parathyroid adenoma in suprasternal fossa, respectively.

INTERVENTIONS

Reoperation for removing nodules in suprasternal fossa and autografted site was performed 1 month later. Then regular hemodialysis 3 times a week with Rocaltrol was continued.

OUTCOMES

During 12 months of follow-up, the joints pain improved obviously and the serum iPTH level ranged from 30.1 to 442 pg/mL.

LESSONS

Although rare, recurrent renal SHPT may be caused by a coexistence of both hyperfunctional autograft and SPG after TPTX+FAT. The Tc-sestamibi parathyroid imaging with SPECT/CT is helpful to locate the culprits of recurrent renal SHPT before reoperation. To prevent recurrence of renal SHPT, the present initial surgical procedures should be further optimized in patient on permanent hemodialysis.

The relationship between inflammatory factors, oxidative stress and DIO-1 concentration in patients with chronic renal failure accompanied with or without euthyroid sick syndrome

Objective

To investigate the relationship between inflammatory factors, oxidative stress and type 1 deiodinase (DIO-1) concentration in patients with chronic renal failure (CRF) with or without euthyroid sick syndrome (ESS).

Methods

This study recruited patients with CRF and divided them into two groups: group 1 had low free triiodothyronine (FT3) levels; and group 2 had normal FT3 levels. Group 3 consisted of healthy volunteers. Serum levels of interleukin (IL)-6, IL-1β, tumour necrosis factor (TNF)-α, 8-isoprostane and DIO-1 were measured using enzyme-linked immunosorbent assays. Multiple regression analysis was used to analyse correlations between parameters.

Results

Sixty patients were enrolled into each group and the groups were comparable in terms of vital signs, white blood cell count, free thyroxine and thyroid stimulating hormone concentrations. The serum DIO-1 concentration was significantly higher in group 2 than in groups 1 and 3. Multivariate regression analysis revealed that the DIO-1 concentration was inversely correlated with the TNF-α concentration.

Conclusions

Patients with CRF without ESS showed higher concentrations of DIO-1 than patients with ESS. The DIO-1 concentration was inversely correlated with the TNF-α concentration, which might indicate that the inflammatory response was milder in the patients with CRF without ESS than in those with ESS.

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.

Endothelial Progenitor Cells and Kidney Diseases

Endothelial progenitor cells (EPC) are bone marrow derived or tissue-resident cells that play major roles in the maintenance of vascular integrity and repair of endothelial damage. Although EPCs may be capable of directly engrafting and regenerating the endothelium, the most important effects of EPCs seem to be depended on paracrine effects. In recent studies, specific microvesicles and mRNAs have been found to mediate the pro-angiogenic and regenerative effects of EPCs on endothelium. EPC counts have important prognostic implications in cardiovascular diseases (CVD). Uremia and inflammation are associated with lower EPC counts which probably contribute to increased CVD risks in patients with chronic kidney disease. Beneficial effects of the EPC therapies have been shown in studies performed on different models of CVD and kidney diseases such as acute and chronic kidney diseases and glomerulonephritis. However, lack of a clear definition and specific marker of EPCs is the most important problem causing difficulties in interpretation of the results of the studies investigating EPCs.