A Retrospective Study of the Impact of Intraoperative Intact Parathyroid Hormone Monitoring During Total Parathyroidectomy for Secondary Hyperparathyroidism: STARD Study

Observation of the efficacy of parathyroidectomy for secondary hyperparathyroidism in hemodialysis patients: a retrospective study

PURPOSE

Parathyroidectomy (PTX) is commonly performed as a treatment for secondary hyperparathyroidism (SHPT) in patients with end-stage renal disease (ESRD). We aimed to evaluate the efficacy of PTX in patients with SHPT who underwent hemodialysis.

METHODS

This retrospective study analyzed the clinical treatment of 80 hemodialysis patients with SHPT who underwent either total PTX with forearm auto transplantation (TPTX + AT) or subtotal parathyroidectomy (SPTX). We compared the changes in biochemical indices before and after surgery as well as the attenuation of intact parathyroid hormone (iPTH) in the TPTX and SPTX groups. We also evaluated clinical symptoms and quality of life using the Visual Analog Scale (VAS) and the Short Form-36 Questionnaire (SF-36) before and at 3, 6, and 12 months after surgery.

RESULTS

Serum iPTH and serum phosphorus levels decreased significantly after surgery in 80 patients with SHPT (P < 0.05). Within one month of surgery, there was a difference in iPTH levels between the TPTX + AT and SPTH groups, but there was no difference over time. Patients experienced significant improvement in their clinical symptoms of restless leg syndrome, skin itching, bone pain, and joint pain at 1 week post operation (P < 0.001). Quality of life significantly improved after surgery, as assessed by SF-36 scores (P < 0.05). Hypocalcemia was the most common postoperative complication, occurring in 35% of patients. Within the first 12 months post surgery, 5 patients had a recurrence.

CONCLUSION

PTX is effective in rapidly reducing iPTH levels, improving calcium and phosphorus metabolism disorders, and enhancing patients' quality of life by safely and effectively relieving clinical symptoms.

Maximal parathyroid gland diameter as a predictive factor for autograft-dependent recurrent secondary hyperparathyroidism after total parathyroidectomy

Introduction

Following total parathyroidectomy (PTx), transcervical thymectomy, and forearm autograft for secondary hyperparathyroidism (SHPT), recurrent SHPT can occur in the autografted forearm. However, few studies have investigated the factors contributing to re-PTx due to autograft-dependent recurrent SHPT before the completion of the initial PTx.

Methods

A total of 770 patients who had autografted parathyroid fragments derived from only one of the resected parathyroid glands (PTGs) and who had undergone successful initial total PTx and transcervical thymectomy-defined by serum intact parathyroid hormone level < 60 pg/mL on postoperative day 1-between January 2001 and December 2022 were included in this retrospective cohort study. Factors contributing to re-PTx due to graft-dependent recurrent SHPT before the completion of the initial PTx were investigated using multivariate Cox regression analysis. Receiver operating characteristic (ROC) curve analysis was performed to obtain the optimal maximum diameter of PTG for autograft.

Results

Univariate analysis showed that dialysis vintage and maximum diameter and weight of the PTG for autograft were significant factors contributing to graft-dependent recurrent SHPT. However, multivariate analysis revealed that dialysis vintage (P=0.010; hazard ratio [HR], 0.995; 95% confidence interval [CI], 0.992-0.999) and the maximum diameter of the PTG for autograft (P=0.046; HR, 1.107; 95% CI, 1.002-1.224) significantly contributed to graft-dependent recurrent SHPT. ROC curve analysis showed that < 14 mm was the optimal maximum diameter of PTG for autograft (area under the curve, 0.628; 95% CI, 0.551-0.705).

Conclusions

The dialysis vintage and maximum diameter of PTG for autograft may contribute to re-PTx due to autograft-dependent recurrent SHPT, which can be prevented by using PTGs with a maximum diameter of < 14 mm for autograft.

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.

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.

Intraoperative intact parathyroid hormone monitoring and frozen section diagnosis are essential for successful parathyroidectomy in secondary hyperparathyroidism

BACKGROUND

Total parathyroidectomy (PTx) is often performed to treat secondary hyperparathyroidism (SHPT). Successful PTx is essential to prevent recurrent and persistent SHPT because remnant parathyroid glands (PTGs) in the neck can be stimulated and may secrete excessive parathyroid hormone (PTH) in end-stage renal disease. However, to date, few studies have investigated factors contributing to successful PTx before the completion of surgery.

MATERIALS AND METHODS

Between August 2010 and February 2020, 344 patients underwent total PTx, transcervical thymectomy, and forearm autograft for SHPT at our institute. Factors contributing to successful PTx before the completion of surgery were investigated. Preoperative imaging diagnoses, including computed tomography, ultrasonography, technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) scintigraphy, intraoperative intact PTH (IOIPTH) monitoring, and frozen section histologic diagnosis, were performed. Successful PTx was defined as intact PTH level < 60 pg/mL on postoperative day 1. A sufficient decrease in IOIPTH level was defined as > 70% decrease in intact PTH levels measured 10 min after total PTx and transcervical thymectomy compared to intact PTH levels measured before skin incision. Logistic regression analysis was conducted to investigate factors contributing to PTx success.

RESULTS

Univariate analysis showed that the number of all PTGs identified preoperatively by imaging modalities and the specimens submitted for frozen section diagnosis, which surgeon presumed to be PTGs, were not significant factors contributing to successful PTx. However, multivariate analysis revealed that the number of PTGs identified by frozen section diagnosis (P < 0.001, odds ratio [OR] 4.356, 95% confidence interval [CI] 2.499-7.592) and sufficient decrease in IOIPTH levels (P = 0.001, OR 7.847, 95% CI 2.443-25.204) significantly contributed to successful PTx.

CONCLUSION

Sufficient intact PTH level decrease observed on IOIPTH monitoring and the number of PTGs identified by frozen section diagnosis contributed to successful PTx for SHPT. IOIPTH monitoring and frozen section diagnosis are essential for achieving successful PTx for SHPT.

Renal hyperparathyroidism

The number of the patients with chronic kidney disease is now increasing in the world. The pathophysiology of renal hyperparathyroidism is closely associated with Klotho-FGF-endocrine axes, which must be solved definitively as early as possible. It was revealed that the expression of fgf23 is activated by calciprotein particles, which induces vascular ossification. And it is well known that phosphorus overload directly increases parathyroid hormone and hyperparathyroid bone disease develops in those subjects. On the other hand, low turnover bone disease is often recently. Both the patients with chronic kidney disease suffering from hyperparathyroid bone disease or low turnover bone disease are associated with increased fracture risk. Micropetrosis may be one of the causes of increased fracture risk in the subjects with low turnover bone disease. In this chapter, we now describe the diagnosis, pathophysiology and treatments of renal hyperparathyroidism.

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.

PTH Spikes During Surgical Treatment for Secondary and Tertiary Hyperparathyroidism: A Prospective Observational Study

BACKGROUND

The aim of the present study was to determine whether PTH spikes in renal hyperparathyroidism can interfere with the interpretation of intraoperative PTH monitoring and to determine its frequency and characteristics.

METHODS

This was a prospective observational study of consecutive patients who underwent surgical treatment in a single tertiary institution. Patients were divided into two groups: spike and no spike. Patients with secondary and tertiary hyperparathyroidism were analyzed separately. Intraoperative PTH monitoring by venous serial samples: two samples were taken before the excision of the parathyroid gland, and two others were taken after resection.

RESULTS

PTH spikes occurred in 23.5% (53 of 226), and their occurrence was similar between secondary and tertiary hyperparathyroidism patients (p = 0.074). The relative PTH spike intensity was higher in transplanted patients than in dialysis patients (55 vs. 20%, p = 0.029). A characteristic of the secondary hyperparathyroidism patients was the highest frequency of surgical failure (23 vs. 7.5%, p = 0.016) and the higher occurrence of supernumerary glands in the spike group (23 vs. 10.3%, p = 0.035). Supernumerary parathyroid was associated with surgical failure [19.1 (6.5-55.7) odds ratio [confidence interval], p < 0.001). In the studies evaluating the diagnostic test validity for patients on dialysis and experiencing spikes, the most significant impacts were in the sensitivity, accuracy, and negative predictive value of the method.

CONCLUSIONS

PTH spikes occurred in up to 23.5% of renal hyperparathyroidism surgical treatments and can negatively influence the intraoperative parathyroid hormone monitoring. Regarding the phenomenon of PTH spikes, it is prudent to think about the possibility of a hyperplastic supernumerary gland.

Diagnostic Accuracy of Intraoperative Intact Parathyroid Hormone Monitoring for Surgical Outcomes of Secondary Hyperparathyroidism

BACKGROUND Intraoperative intact parathyroid hormone (IO-iPTH) monitoring has not reached a consensus in predicting surgical outcomes of secondary hyperparathyroidism. Here, we explore the predictive effect of IO-iPTH monitoring on surgical outcomes of secondary hyperparathyroidism as a potentially effective standard. MATERIAL AND METHODS We enrolled 119 patients who underwent total parathyroidectomy with autotransplantation from January 2016 to August 2019. Intact parathyroid hormone (iPTH) levels were tested 1 day before surgery (iPTHpre), 10 min after glands resection (iPTH10min), and 1 and 7 days after the operation (iPTHd1, iPTHd7). According to iPTHpre levels, patients were divided into a <2000 pg/ml group and a ≥2000 pg/ml group, and the cutoff values were compared. In patients with successful parathyroidectomy, the value of iPTHpre minus iPTH10min (iPTHdec) and relative-iPTH10min were compared between groups. RESULTS Using cutoff values, the predictive criterion was defined as iPTH10min ≤314.5 pg/ml or relative-iPTH10min ≤12.4%. In the iPTHpre ≥2000 pg/ml group, iPTH10min had a higher predictive value (318 pg/ml vs 218 pg/ml) whereas relative-iPTH10min had a lower predictive value (12.1% vs 20.3%). In patients with successful PTX, the iPTHdec value of the iPTHpre ≥2000 pg/ml group was significantly higher than that of the <2000 pg/ml group. Additionally, the relative-iPTH10min was significantly lower in the ≥2000 pg/ml group than in the <2000 pg/ml group. CONCLUSIONS An intraoperative predictive criterion of iPTH10min ≤314.5 pg/ml or relative-iPTH10min ≤12.4% is associated with effectively predicting surgical success of secondary hyperparathyroidism. The predictive value is affected by iPTHpre level; therefore, a variable prediction standard based on iPTHpre levels shall be established.

The Usefulness of Intraoperative PTH as a Predictor for Successful Parathyroidectomy in Secondary Hyperparathyroidism

Introduction: Secondary hyperparathyroidism (SHPT) is a multisystemic syndrome that affects calcium and bone homeostasis in patients with chronic kidney disease (CKD). Despite medical treatment, 1–2% of patients require parathyroidectomy annually. The use of an intraoperative parathormone protocol (IOPTH) to predict cure is still in debate, due to the lack of standardized protocols, the use of different assays, and uneven PTH clearance. This study aimed to determine the diagnostic accuracy of an IOPTH in patients with SHPT for predicting successful surgery after parathyroidectomy.

Methods: About 30 patients were enrolled. A prospective observational study (cohort) was performed in patients who were submitted to parathyroidectomy by an endocrine surgeon for SHPT. All were submitted to a bilateral neck exploration with a subtotal parathyroidectomy. Three IOPTH determinations were withdrawn: at anesthetic induction (PTH₀), 15 min (PTH₁₅), and 30 min (PTH₃₀) after completion of gland resection. Another sample was taken 24 h after the procedure (PTH₂₄), values <150 pg/mL defined a successful surgery, and patients were assigned to the success or failure group. IOPTH drop was analyzed to predict successful surgery with drops of 70 and 90% at 15 and 30 min, respectively.

Results: A total of 26 patients were included, 19 patients were in the successful group. IOPTH showed a significant difference between groups in their absolute PTH₁₅ and PTH₃₀ values. A significant difference was also found in their PTH drop at 30 min (81 vs. 91%, p = 0.08). For predicting a successful surgery, having a PTH drop >90% at 30 min was the most significant factor [Odds Ratio (OR) 3.0 (1.5–4) IC 95%].

Conclusions: This study points toward a stricter and staggered IOPTH protocol to predict a successful surgery. Our results suggest taking a PTH₁₅ expecting a PTH drop of >90%. If this is not achieved, reexploration and a PTH₃₀ sample are suggested to accurately predict success.

Intraoperative recurrent laryngeal nerve monitoring using endotracheal electromyography during parathyroidectomy for secondary hyperparathyroidism

Objective

To investigate the factors associated with adherence of an enlarged parathyroid gland to the recurrent laryngeal nerve (RLN) and the effectiveness of intraoperative neural monitoring (IONM).

Methods

This single-center retrospective study involved samples from 197 consecutive patients (394 RLNs; 733 parathyroid glands) who underwent parathyroidectomy and transcervical thymectomy between September 2010 and December 2014. The presence of parathyroid gland adhesion to the RLN and the clinical characteristics of patients with and without nerve adhesion were recorded. All patients underwent intraoperative monitoring of the electromyographic responses of the vocal cords using the endotracheal NIM-Response 3.0 system. The patients’ postoperative clinical outcomes were recorded.

Results

Parathyroid gland adhesion to the RLN was significantly associated with maximum gland diameter (>15 mm), weight (>500 mg), and the presence of nodular hyperplasia. IONM demonstrated a sensitivity of 97.8%, specificity of 43.5%, and accuracy of 94.7% for detecting nerve damage. Parathyroid gland adhesion to 17 RLNs occurred in 3 cases (17.6%) of vocal cord paralysis, whereas the 377 glands without nerve adhesion resulted in vocal cord paralysis in 20 cases (5.3%).

Conclusion

Our findings demonstrated the effectiveness of IONM using endotracheal electromyography in patients who underwent parathyroidectomy for secondary hyperparathyroidism.

Diagnostic Values of Intraoperative (1-84) Parathyroid Hormone Levels are Superior to Intact Parathyroid Hormone for Successful Parathyroidectomy in Patients With Chronic Kidney Disease

OBJECTIVE

Persistent secondary hyperparathyroidism (SHPT) may occur because of residual cervicothoracic parathyroids in parathyroidectomy (PTX) patients with chronic kidney disease. We prospectively compared the predictive values of intraoperative plasma (1-84) parathyroid hormone (PTH) and intact PTH (iPTH) levels to improve the safety and efficacy of PTX.

METHODS

We included 100 healthy controls, 162 stage 5 chronic kidney disease patients without SHPT, and 214 patients who underwent PTX because of SHPT. Plasma iPTH and (1-84) PTH levels were measured before incision (io-iPTH0 and io-[1-84]PTH0, respectively) and 10 minutes (io-iPTH10 and io-[1-84]PTH10, respectively) and 20 minutes (io-iPTH20 and io-[1-84]PTH20, respectively) after removing all parathyroids. The percentage reduction of iPTH and (1-84) PTH at 10 minutes (io-iPTH10% and io-[1-84]PTH10%, respectively) and 20 minutes (io-iPTH20%, and io-[1-84]PTH20%, respectively) was calculated. iPTH and (1-84) PTH were measured using second- and third-generation PTH assays, respectively.

RESULTS

Compared with the controls and non-PTX patients, the PTX group had more obvious mineral metabolism disorders. There were 187 successful PTXs, 19 patients with persistent SHPT, and 8 patients lost to follow-up. The receiver operating characteristic curves revealed that io-(1-84)PTH10% >86.6% and io-(1-84)PTH20% >87.5% suggested successful PTX. The sensitivity of io-iPTH20% and io-(1-84)PTH20% were higher than those at the timepoint of 10 minutes. Moreover, the specificity and sensitivity of the (1-84) PTH reduction percentage were superior to that of iPTH.

CONCLUSION

Intraoperative reduction percentages of plasma (1-84) PTH levels are superior to iPTH for accurately predicting successful PTX, especially at 20 minutes after all cervicothoracic parathyroids had been resected.

Intact parathyroid hormone levels localize causative glands in persistent or recurrent renal hyperparathyroidism: A retrospective cohort study

Persistent or recurrent renal hyperparathyroidism may occur after total parathyroidectomy and transcervical thymectomy with forearm autograft under continuous stimulation due to uremia. Parathyroid hormone (PTH) levels may reflect persistent or recurrent renal hyperparathyroidism because of the enlarged autografted parathyroid glands in the forearm or remnant parathyroid glands in the neck or mediastinum. Detailed imaging requires predictive localization of causative parathyroid glands. Casanova and simplified Casanova tests may be convenient. However, these methods require avascularization of the autografted forearm for >10 min with a tourniquet or Esmarch. The heavy pressure during avascularization can be incredibly painful and result in nerve damage. An easier method that minimizes the burden on patients in addition to predicting the localization of causative parathyroid glands was developed in this study. Ninety patients who underwent successful re-parathyroidectomy for persistent or recurrent renal hyperparathyroidism after parathyroidectomy between January 2000 and July 2019 were classified according to the localization of causative parathyroid glands (63 and 27 patients in the autografted forearm and the neck or mediastinum groups, respectively). Preoperatively, intact PTH levels were measured from bilateral forearm blood samples following a 5-min avascularization of the autografted forearm. Cutoff values of the intact PTH ratio (intact PTH level obtained from the non-autografted forearm before re-parathyroidectomy/intact PTH level obtained from the autografted forearm before re-parathyroidectomy) were investigated with receiver operating characteristic curves to localize the causative parathyroid glands. Intact PTH ratios of <0.310 with an area under the curve (AUC) of 0.913 (95% confidence interval [CI]: 0.856–0.970; P < 0.001) and >0.859 with an AUC 0.744 (95% CI: 0.587–0.901; P = 0.013) could predict causative parathyroid glands in the autografted forearm and the neck or mediastinum with diagnostic accuracies of 81.1% and 83.3%, respectively. Therefore, we propose that the intact PTH ratio is useful for predicting the localization of causative parathyroid glands for re-parathyroidectomy.

Critical analysis of the intraoperative parathyroid hormone decrease during parathyroidectomy for secondary and tertiary hyperparathyroidism

BACKGROUND

This study aims to determine whether intraoperative parathyroid hormone monitoring helps to predict early surgical outcomes in patients with renal hyperparathyroidism and evaluate the impact on decision making during surgery.

METHODS

A prospective study was conducted. Serial samples of the intraoperative parathyroid hormone were collected; 2 of these were taken before the excision, and 2 were taken after the planned parathyroid resection (10 minutes and 15 minutes). We tested the criterion of an intraoperative parathyroid hormone percentage decay ≥80% of the highest value of the basal samples as a predictor of success.

RESULTS

Of the 228 patients, parathyroidectomy achieved success in 92.1%. In patients with secondary hyperparathyroidism, the failure group showed a tendency to stabilize or even increase the intraoperative parathyroid hormone values from the 10-minute measure (577 pg/mL) to the 15-minute measure (535 pg/mL) (P = .903). Conversely, intraoperative parathyroid hormone continued to drop in those with a successful outcome: 245 pg/mL (10 minutes) and 206 pg/mL (15 minutes) (P < .001). The failure group had a significantly lower percentage decay (P < .001) from baseline when compared with the success group. The intraoperative parathyroid hormone influenced the surgical management in up to 7% of the cases. The intraoperative parathyroid hormone dosage method showed an accuracy of 86%, a sensitivity of 88%, and specificity of 67%.

CONCLUSION

In patients with renal hyperparathyroidism undergoing parathyroidectomy, the use of intraoperative parathyroid hormone may help to predict an early therapeutic outcome with high sensitivity and accuracy by indicating the operation's success when there is an 80% reduction of baseline intraoperative parathyroid hormone 15 minutes after removal of the enlarged glands, an associated continuous decrease in serum intraoperative parathyroid hormone levels between 10 and 15 minutes, and achievement of plasma target values <500 pg/mL.

Perioperative hyperkalemia in hemodialysis patients undergoing parathyroidectomy for renal hyperparathyroidism

The present study investigates the incidence of perioperative hyperkalemia and the influence factors of serum potassium levels during and after parathyroidectomy (PTX) in hemodialysis patients with renal hyperparathyroidism (rHPT). A total of 204 hemodialysis patients with refractory rHPT undergoing successful total parathyroidectomy with autotransplantation (tPTX + AT) were analyzed retrospectively. Hyperkalemia was defined as serum potassium levels ≥ 5.5 mmol/L. The preoperative baseline level of serum potassium (K _base⁺ ) was defined as a mean of the three preoperative prehemodialysis serum potassium levels. The higher levels of serum potassium during and immediately after surgery were recorded as K _d0⁺ and the peak prehemodialysis serum potassium levels 3 days after surgery as K _d3⁺ . 136/204 (66.7%) patients suffered from hyperkalemia during or immediately after surgery and 65/204 (31.9%) patients were affected with prehemodialysis hyperkalemia 3 days after surgery. K _base⁺ was the only influencing factor for K _d0⁺ . Serum K _base⁺ , preoperative serum alkaline phosphatase, and total calcium supplement dosage during intravenous calcium supplement were the influencing factors for K _d3⁺ . In the case of PTX, the serum potassium levels of patients with higher serum K _base⁺ and severe postoperative hypocalcemia need to be monitored with extended attention perioperatively.

Pattern of Intraoperative Parathyroid Hormone and Calcium in the Treatment of Tertiary Hyperparathyroidism

OBJECTIVE

Tertiary hyperparathyroidism, an autonomous hyperproduction of parathyroid hormone (PTH), has a challenge in its treatment. This study asked whether the intraoperative PTH and calcium drop can confirm the resection of all parathyroid tissues.

STUDY DESIGN

Case series with planned data collection.

SETTING

Tertiary referral medical center.

SUBJECTS AND METHODS

The study assessed patients with tertiary hyperparathyroidism who were treated at the Hospital of the State University of Campinas from 2007 to 2015. All patients underwent total parathyroidectomy with autotransplantation of parathyroid fragments. PTH and calcium were collected during the preoperative period; at 10, 20, and 240 minutes after resection of the glands; and at 1 year after the procedure. Data were analyzed by analysis of variance and logistic regression analysis with statistical values of P < .05.

RESULTS

Thirty-five patients were assessed: 17 women (48.57%) and 18 men (51.43%). The percentage of PTH drop was statistically significant at all times, unlike the calcium analysis, but only PTH collected at 20 minutes was able to confirm the removal of all parathyroid tissues (P = .029). Based on the receiver operating characteristic curve, the 71.2% drop obtained high sensitivity and specificity (P = .028).

CONCLUSIONS

Treatment success can be predicted by analyzing the decrease of intraoperative PTH and not by calcium. The 71.2% PTH drop at 20 minutes after parathyroidectomy had high sensitivity and specificity to predict surgical cure.

Bone metabolism markers and hungry bone syndrome after parathyroidectomy in dialysis patients with secondary hyperparathyroidism

OBJECTIVE

To explore the short-term variation in bone metabolic markers and the characteristics of hungry bone syndrome (HBS) after parathyroidectomy (PTX) with forearm autotransplantation in uremic patients with secondary hyperparathyroidism (SHPT) and to provide a basis for the pathogenesis, diagnosis and treatment of metabolic bone disease in SHPT.

METHODS

A total of 115 patients with SHPT receiving PTX from July 2015 to December 2017, hospitalized at the First Affiliated Hospital of Nanjing Medical University, were enrolled in our study. We retrospectively analyzed the baseline clinical data, the levels of bone metabolism markers before and on the third day after PTX, and the risk factors predicting HBS.

RESULTS

Preoperative baseline data showed that the levels of bone metabolic markers such as bone metabolism-regulating hormones: iPTH, calcitonin (CT); bone formation markers: phosphatase (ALP), osteocalcin (OC); bone resorption markers: type I collagen cross-linked N-telopeptides (NTX), type I collagen cross-linked C-telopeptides (CTX), tartrate-resistant acid phosphatase 5b (TRAP-5b) were all increased compared to normal levels. The levels of postoperative serum iPTH, CT, CTX and TRAP-5b decreased significantly compared to preoperative levels, while the levels of OC and ALP increased significantly. Of the 115 patients, 101 (87.8%) developed HBS after PTX. High preoperative serum ALP and low preoperative serum calcium level independently predicted the occurrence of HBS. Younger preoperative age, high preoperative serum ALP and iPTH level independently predicted the severity of HBS.

CONCLUSIONS

In severe SHPT, both bone formation and resorption were active, which suggested the presence of high-turnover bone diseases characterized by up-regulation of osteoclasts-osteoblasts functionally coupling activation in the patients. PTX could promote osteoblast activity and reduce osteoclast activity. HBS was common after PTX. Preoperative higher serum ALP and lower calcium were independent predictors of the occurrence of HBS. Younger patients with higher preoperative ALP and PTH may need to closely monitor serum calcium levels and intensive calcium supplementation after 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.

Peritoneal dialysis can alleviate the clinical course of hungry bone syndrome after parathyroidectomy in dialysis patients with secondary hyperparathyroidism

PURPOSE

It is unclear whether clinical courses of hungry bone syndrome (HBS) after parathyroidectomy (PTX) in peritoneal dialysis (PD) and hemodialysis (HD) patients are different. The present study aimed to investigate the possible differences of postoperative hypocalcemia and hyperkalemia between PD and HD patients.

METHODS

We performed retrospectively 29 PD patients as the PD group and 169 HD patients as the HD group undergoing successful total PTX with autotransplantation. Calcium supplement after surgery was recorded. Higher levels of serum potassium during and immediately after surgery were recorded as K⁺_d0. K⁺_d3 was recorded as peak pre-dialysis serum potassium level 3 days post-surgery.

RESULTS

There were 157 (92.90%) patients in HD group and 22 (75.86%) patients in PD group suffered from HBS after surgery, with significant difference between the groups (P = 0.004). Patients in PD group had significantly shorter intravenous calcium supplement duration (P = 0.037) and significantly smaller intravenous calcium supplement dosage (P = 0.042) and total calcium supplement dosage during hospitalization (P = 0.012) than patients in HD group. The levels of serum K⁺_d0 (P < 0.001) and K⁺_d3 (P < 0.001) were both significantly lower in PD group than those in HD group. Peritoneal dialysis was one of the independent influencing factors with negative correlation for calcium supplement, serum K⁺_d0 and serum K⁺_d3.

CONCLUSIONS

Compared with HD patients, the clinical course of HBS after PTX in PD patients was alleviated. Efforts should be devoted to individual perioperative management for PD patients undergoing PTX.

Hypocalcemia-based prediction of hungry bone syndrome after parathyroidectomy in hemodialysis patients with refractory secondary hyperparathyroidism

Objective

This study was performed to explore the risk factors for hungry bone syndrome (HBS) and establish prediction equations for calcium supplementation after parathyroidectomy in hemodialysis patients with secondary hyperparathyroidism.

Methods

We retrospectively analyzed data from 252 hemodialysis patients undergoing successful total parathyroidectomy with autotransplantation. HBS was defined according to a minimum postoperative serum corrected calcium (PcCa) concentration of <2.0 mmol/L. Independent predictors of HBS were analyzed, and prediction equations for HBS were derived accordingly.

Results The incidence of HBS was 71.4%. The serum corrected calcium and preoperative serum alkaline phosphatase (ALP) concentrations were independent predictors of HBS. The preoperative serum ALP, intact parathyroid hormone (iPTH), and hemoglobin concentrations were independent factors influencing the average descending velocity of the PcCa concentration before calcium supplementation (PcCa-V), intravenous calcium supplement holding time (IVCa-T), and intravenous calcium supplement dosage (IVCa), while the serum ALP and iPTH concentrations were independent predictors of the oral calcium supplement dosage (OCa). Four prediction equations for PcCa-V, IVCa-T, IVCa, and OCa were established.

Conclusions

Establishment of prediction equations for HBS may contribute to a new individualized therapy for patients with HBS.

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.

Niche point-of-care endocrine testing - Reviews of intraoperative parathyroid hormone and cortisol monitoring

Point-of-care (POC) testing, which provides quick test results in near-patient settings with easy-to-use devices, has grown continually in recent decades. Among near-patient and on-site tests, rapid intraoperative and intra-procedural assays are used to quickly deliver critical information and thereby improve patient outcomes. Rapid intraoperative parathyroid hormone (ioPTH) monitoring measures postoperative reduction of parathyroid hormone (PTH) to predict surgical outcome in patients with primary hyperparathyroidism, and therefore contributes to the change of parathyroidectomy to a minimally invasive procedure. In this review, recent progress in applying ioPTH monitoring to patients with secondary and tertiary hyperparathyroidism and other testing areas is discussed. In-suite cortisol monitoring facilitates the use of adrenal vein sampling (AVS) for the differential diagnosis of primary aldosteronism and adrenocorticotropic hormone (ACTH)-independent Cushing syndrome. In clinical and psychological research settings, POC testing is also useful for rapidly assessing cortisol in plasma and saliva samples as a biomarker of stress. Careful resource utilization and coordination among stakeholders help to determine the best approach for implementing cost-effective POC testing. Technical advances in integrating appropriate biosensors with microfluidics-based devices hold promise for future real-time POC cortisol monitoring.

Value of Intraoperative Parathyroid Hormone Assay during Parathyroidectomy in Dialysis and Renal Transplant Patients with Secondary and Tertiary Hyperparathyroidism

BACKGROUND

In dialysis and renal transplant patients with secondary and tertiary hyperparathyroidism (HPT), the value of intraoperative parathyroid hormone (ioPTH) during parathyroidectomy (PTX) and its association with long-term PTH levels are unknown. The present study aims at evaluating the relationship of ioPTH with long-term PTH levels post-PTX in dialysis and renal transplant patients in a single-center study.

METHODS

The ioPTH was measured in 57 dialysis patients (33 females and 24 males) and 18 renal transplant recipients (12 males and 6 females) who underwent PTX from 2005 to 2015 for refractory HPT. Near-total PTX was performed in 56 patients and total PTX with autotransplantation in 20 patients. The PTH monitoring included 3 samples: pre-intubation, 10- and 20-min (pre-ioPTH, 10-ioPTH, and 20-ioPTH) post parathyroid gland excision. Patients were followed up for up to 5 years.

RESULTS

In the dialysis group, the median (25th-75th percentile) pre-, 10-, and 20-ioPTH levels were 1,447 pg/mL (938-2,176), 143 pg/mL (78-244) and 112 pg/mL (59-153) respectively. In the renal transplant group, pre-, 10-, and 20-ioPTH levels were 273 pg/mL (180-403), 42 pg/mL (25-72), and 34 pg/mL (23-45) respectively. All patients in the transplant group had a functional kidney transplant at the time of PTX with a median serum creatinine of 1.3 mg/dL (1.2-1.7) and estimated glomerular filtration rate of 55 mL/min (40-60). The median time between renal transplant and PTX surgeries was 22 months (7-81). The last median follow-up PTH level was 66 pg/mL (15-201) in the dialysis group and 54 pg/mL (17-72) in the transplant group (p = 0.438). The mean time for last PTH post-PTX was 2.3 ± 2.0 years. In both groups, there was no significant difference between 20-ioPTH and any-time post-PTX PTH levels (p = 0.6 and p = 0.9). Nineteen patients (25%) were readmitted within 90 days because of hypocalcemia. One patient in the dialysis group was readmitted for post-PTX hematoma evacuation. No patient required repeat PTX because of recurrent HPT that was refractory to medical therapy. Only one dialysis patient required repeat PTX because the first procedure failed.

CONCLUSIONS

The 20-ioPTH is a good indicator of long-term PTH levels in dialysis and renal transplant patients. Hypocalcemia is a common complication, particularly in dialysis patients, and it is the main reason for readmission after PTX. Hypoparathyroidism is a potential concern after PTX in dialysis patients.

Location Frequency of Missed Parathyroid Glands After Parathyroidectomy in Patients with Persistent or Recurrent Secondary Hyperparathyroidism

BACKGROUND

Reoperative parathyroidectomy (RPTX) because parathyroid glands have been missed is frequently required in patients with secondary hyperparathyroidism (SHPT). The usual locations of these missed glands in patients with SHPT are yet to be fully elucidated.

METHODS

We retrospectively investigated the locations of missed glands in 165 patients who underwent RPTX for persistent or recurrent SHPT at our institution from August 1982 to July 2014. At our institution, total parathyroidectomy with forearm autograft is the routine operative procedure for SHPT. We also routinely resect the thymic tongue.

RESULTS

Of 165 patients, 82 underwent initial parathyroidectomy at our institution (Group A), and the remaining 83 underwent initial parathyroidectomy at other institutions (Group B). A total of 239 parathyroid glands were resected (Group A, 93; Group B, 146). Missed glands were most commonly located in the mediastinum (Group A, 22/93) and the thymic tongue (Group B, 31/146).

CONCLUSIONS

In patients with persistent or recurrent SHPT, ectopic parathyroid glands are frequently located in the mediastinum and thymic tongue. Therefore, resecting the thymic tongue during the initial operation may reduce the need for RPTX.

Diagnostic Accuracy Study of Intraoperative and Perioperative Serum Intact PTH Level for Successful Parathyroidectomy in 501 Secondary Hyperparathyroidism Patients

Parathyroidectomy (PTX) is an effective treatment for severe secondary hyperparathyroidism (SHPT); however, persistent SHPT may occur because of supernumerary and ectopic parathyroids. Here a diagnostic accuracy study of intraoperative and perioperative serum intact parathyroid hormone (iPTH) was performed to predict successful surgery in 501 patients, who received total PTX + autotransplantation without thymectomy. Serum iPTH values before incision (io-iPTH0), 10 and 20 min after removing the last parathyroid (io-iPTH10, io-iPTH20), and the first and fourth day after PTX (D1-iPTH, D4-iPTH) were recoded. Patients whose serum iPTH was >50 pg/mL at the first postoperative week were followed up within six months. Successful PTX was defined if iPTH was <300 pg/mL, on the contrary, persistent SHPT was regarded. There were 86.4% patients underwent successful PTX, 9.8% remained as persistent SHPT and 3.8% were undetermined. Intraoperative serum iPTH demonstrated no significant differences in two subgroups with or without chronic hepatitis. Receiver operating characteristic (ROC) curves showed that >88.9% of io-iPTH20% could predict successful PTX (area under the curve [AUC] 0.909, sensitivity 78.6%, specificity 88.5%), thereby avoiding unnecessary exploration to reduce operative complications. D4-iPTH >147.4 pg/mL could predict persistent SHPT (AUC 0.998, sensitivity 100%, specificity 99.5%), so that medical intervention or reoperation start timely.