Predicting postoperative total calcium requirements after parathyroidectomy in secondary hyperparathyroidism

A nomogram prediction model for hungry bone syndrome in dialysis patients with secondary hyperparathyroidism after total parathyroidectomy

OBJECTIVE

Secondary hyperparathyroidism (SHPT) is a common complication of chronic kidney disease (CKD). Hungry bone syndrome (HBS) after parathyroidectomy (PTX) is a serious complication, which can lead to diarrhea, convulsion, arrhythmia and even death. This study was aimed to determine the risk factors for HBS after PTX in dialysis patients with SHPT and construct a nomogram prediction model to predict the incidence of postoperative complications.

METHODS

Clinical data were collected from 80 maintenance hemodialysis (MHD) patients with SHPT who received total PTX in the Second Hospital of Jilin University from January 2018 to September 2021. In line with the inclusion and exclusion criteria, totally 75 patients were finally enrolled for analysis. Patients were divided into two groups for retrospective analysis according to the severity of postoperative HBS, including HBS group and non-HBS (N-HBS) group. Univariate and multivariate logistic regression analyses were conducted to determine the risk factors for postoperative HBS. Afterwards, the receiver operating characteristic (ROC) curves were plotted based on the statistical analysis results, aiming to compare the prediction effects of different predicting factors. Finally, the nomogram was established to evaluate the occurrence probability of postoperative complications predicted by the risk factors.

RESULTS

Among the 75 patients, 32 had HBS (HBS group), while 43 did not have HBS (N-HBS group). Univariate analysis results indicated that, the preoperative intact parathyroid hormone (iPTH) and serum alkaline phosphatase (ALP) levels in HBS group were significantly higher than those in N-HBS group, while preoperative hemoglobin and preoperative albumin (Alb) levels were significantly lower than those in N-HBS group. As discovered by multivariate logistic regression analysis, preoperative iPTH (OR = 1.111, P = 0.029) and ALP (OR = 1.010, P < 0.001) were the independent risk factors for postoperative HBS. ROC curve analysis suggested that the area under the curve (AUC) values of these two indicators were 0.873 and 0.926, respectively (P < 0.0001). Subsequently, the nomogram model for predicting HBS was constructed. The model verification results indicated that the predicted values were basically consistent with the measured values, with the C-index of 0.943 (95% CI 0.892-0.994). Besides, the calibration curve was consistent with the ideal curve, demonstrating the favorable accuracy and discrimination of the model.

CONCLUSIONS

Preoperative iPTH and preoperative ALP are the risk factors for postoperative HBS, which can be used to guide the early clinical intervention.

Brown Tumour in Chronic Kidney Disease: Revisiting an Old Disease with a New Perspective

Osteitis fibrosa cystica (OFC) and Brown Tumours are two related but distinct types of bone lesions that result from the overactivity of osteoclasts and are most often associated with chronic kidney disease (CKD). Despite their potential consequences, these conditions are poorly understood because of their rare prevalence and variability in their clinical manifestation. Canonically, OFC and Brown Tumours are caused by secondary hyperparathyroidism in CKD. Recent literature showed that multiple factors, such as hyperactivation of the renin-angiotensin-aldosterone system and chronic inflammation, may also contribute to the occurrence of these diseases through osteoclast activation. Moreover, hotspot KRAS mutations were identified in these lesions, placing them in the spectrum of RAS-MAPK-driven neoplasms, which were until recently thought to be reactive lesions. Some risk factors contributed to the occurrence of OFC and Brown Tumours, such as age, gender, comorbidities, and certain medications. The diagnosis of OFC and Brown Tumours includes clinical symptoms involving chronic bone pain and laboratory findings of hyperparathyroidism. In radiological imaging, the X-ray and Computed tomography (CT) scan could show lytic or multi-lobular cystic alterations. Histologically, both lesions are characterized by clustered osteoclasts in a fibrotic hemorrhagic background. Based on the latest understanding of the mechanism of OFC, this review elaborates on the manifestation, diagnosis, and available therapies that can be leveraged to prevent the occurrence of OFC and Brown Tumours.

A New Calculation Model for Calcium Requirements After Parathyroidectomy in Patients With Secondary Hyperparathyroidism

OBJECTIVES

We aimed to develop a new calculation model for calcium requirements in dialysis patients following parathyroidectomy.

METHODS

A total of 98 patients with secondary hyperparathyroidism receiving parathyroidectomy from January 2014 to January 2022 were enrolled in this study. Among these patients, 78 were randomly selected for construction of the calcium requirement calculation model, and the remaining 20 patients were selected for model validation. The calcium requirement model estimated the total calcium supplementation for 1 week after surgery using variables with significant relationships in the derivation group by stepwise multiple linear regression analysis. Bias, precision, and accuracy were measured in the validation group to determine the performance of the model.

RESULTS

The model was as follows: calcium requirement for 1 week after surgery=33.798-8.929×immediate postoperative calcium+0.190×C-reactive protein-0.125×age+0.002×preoperative intact parathyroid hormone+0.003×preoperative alkaline phosphatase (R2=0.8). The model was successfully validated.

CONCLUSION

We generated a novel model to guide calcium supplementation. This model can assist in stabilizing the serum calcium levels of patients during the early postoperative period. Furthermore, it contributes to the individualized and precise treatment of hypocalcemia in patients following parathyroidectomy.

A reappraisal of risk factors for early hypocalcemia after parathyroidectomy in dialysis patients

We aimed to identify risk factors for early hypocalcemia after parathyroidectomy in patients with secondary hyperparathyroidism. We retrospectively enrolled 106 of 120 consecutive patients with secondary hyperparathyroidism who underwent parathyroidectomy between January 2019 and July 2021. Perioperative laboratory parameters, preoperative computerized tomography (CT) images, and postoperative histology were evaluated. Parathyroid calcification was defined as hyperdense regions with a density of > 130 Hounsfield Units on CT images of the parathyroid. Subtotal parathyroidectomy, total parathyroidectomy without auto-transplantation, or total parathyroidectomy with auto-transplantation were performed in the present study. Postoperative hypocalcemia was defined as a serum calcium concentration < 2.1 mmol/L within 4 days of surgery. The participants were categorized according to the presence (n = 33) or absence (n = 73) of postoperative hypocalcemia. The demographics, comorbidities, and surgical details were similar in the two groups. Multivariate analysis showed that the preoperative alkaline phosphatase activity, serum intact parathyroid hormone and calcium concentrations, and parathyroid calcification were independent risk factors for postoperative hypocalcemia (all P < 0.05). Receiver operating characteristic analysis generated areas under the curves for preoperative alkaline phosphatase, intact parathyroid hormone, and parathyroid calcification of 0.82, 0.80, and 0.70, respectively (all P < 0.05). Cut-off values for preoperative alkaline phosphatase (> 242.9 IU/L) and intact parathyroid hormone (> 2,104 pg/mL) were found to be predictive of postoperative hypocalcemia. High preoperative alkaline phosphatase activity and serum intact parathyroid hormone concentration and low serum calcium are associated with higher risks of postoperative hypocalcemia. Calcification of the parathyroid may represent a novel radiologic means of predicting postoperative hypocalcemia.

Factors influencing the development of bone starvation syndrome after total parathyroidectomy in patients with renal hyperparathyroidism

Purpose

To investigate the factors affecting the development of bone starvation syndrome (HBS) after total parathyroidectomy in patients with renal hyperparathyroidism (SHPT).

Patients and methods

The clinical data and perioperative indices of 141 patients who underwent PTX for SHPT were retrospectively analyzed. The patients were divided into HBS and non-HBS groups based on postoperative minimum blood calcium <1.87 mmol/L. The differences in general clinical data and perioperative related indices between the two groups were compared; logistic regression analysis was performed to analyze the risk factors influencing HBS occurrence after surgery. Multiple linear regression method was used to analyze the factors influencing the maintenance time of intravenous calcium supplementation and total amount of calcium supplementation during intravenous calcium supplementation. The threshold value for the diagnosis of HBS was analyzed using the ROC subjects' working curve.

Results

HBS occurred in 46 (32.6%) patients. Univariate analysis showed statistically significant differences in dialysis age, preoperative calcitonin, preoperative parathyroid hormone, preoperative blood phosphorus, and preoperative alkaline phosphatase between both groups (P < 0.05). Logistic regression analysis using stepwise entry method concluded that preoperative alkaline phosphatase was an independent factor for the development of HBS after surgery. Preoperative parathyroid hormone was an independent factor for the duration of intravenous calcium supplementation and total calcium supplementation during intravenous calcium supplementation in the HBS group. Based on the ROC curve, for postoperative HBS, the cut-off ALP value was 199.5 U/L, with a sensitivity of 80.85% and specificity of 82.61%.

Conclusion

Preoperative serum ALP may be an independent factor for HBS occurrence after surgery. When preoperative ALP > 199.5 U/L, patients with SHPT are prone to HBS after surgery, and the higher the preoperative ALP, the higher the incidence of HBS, and vice versa. In addition, preoperative PTH may be the factor in the timing of postoperative intravenous calcium supplementation and the total amount of calcium supplementation during intravenous calcium supplementation in patients with HBS.

Effect of calcium supplementation on severe hypocalcemia in patients with secondary hyperparathyroidism after total parathyroidectomy

BACKGROUND

Severe hypocalcemia (SH) is a dreaded complication of total parathyroidectomy (TPTX) without auto-transplantation.

AIM

To compare conventional and preventive calcium supplementation (CS) regimens in terms of SH occurrence after TPTX.

METHODS

This retrospective study included patients who underwent TPTX between January 2015 and May 2018 at the China-Japan Friendship Hospital. From January 2015 to May 2016, conventional CS was performed in patients who underwent TPTX, with calcium amounts adjusted according to postoperative serum calcium levels. From October 2016 to May 2018, preventive CS was performed according to preoperative alkaline phosphatase (ALP) levels. The patients were defined as low-risk (ALP < 500 U/L) and high-risk (ALP > 500 U/L) for SH. All preoperative blood samples were collected in the fasting state on the day before surgery. Postoperative blood samples were obtained at 6-7 AM from the first postoperative day.

RESULTS

A total of 271 patients were included. These patients were 47.7 ± 11.1 years old, and 57.6% were male. Their mean body mass index (BMI) was 22.9 ± 3.8 kg/m². There were no significant differences in sex, age, BMI, preoperative ALP, serum calcium, serum phosphorus, calcium-phosphorus ratio, and intact parathyroid hormone (iPTH) between the two CS groups. Compared with conventional CS, preventive CS led to lower occurrence rates of hypocalcemia within 48 h (46.0% vs 74.5%, P < 0.001) and SH (31.7% vs 64.1%, P < 0.001). Multivariable analysis showed that preoperative iPTH levels [odds ratio (OR) = 1.001, 95% confidence interval (CI): 1.000-1.001, P = 0.009), preoperative ALP amounts (OR = 1.002, 95%CI: 1.001-1.003, P = 0.002), preoperative serum phosphorus levels (OR = 8.729, 95%CI: 1.518-50.216, P = 0.015) and preventive CS (OR = 0.132, 95%CI: 0.067-0.261, P < 0.001) were independently associated with SH. In patients with preoperative ALP ≥ 500 U/L, only preventive CS (OR = 0.147, 95%CI: 0.038-0.562. P = 0.005) was independently associated with SH.

CONCLUSION

This study suggests that preventive CS could reduce the occurrence of SH, indicating its critical value for hypocalcemia after TPTX.

Outcomes following parathyroidectomy for secondary hyperparathyroidism in patients with chronic kidney disease - a single-centre study

BACKGROUND

Surgical parathyroidectomy may be required for severe and refractory secondary hyperparathyroidism (SHPT) in patients with chronic kidney disease (CKD). Parathyroidectomy is associated with long-term survival benefit despite an increase in short-term morbidity and mortality. Global variation in practice exists, with limited Australian data on outcomes following parathyroidectomy.

METHODS

We conducted a retrospective study of patients who underwent parathyroidectomy for SHPT between January 2010 and December 2019 at a single tertiary referral centre in Melbourne, Australia. Biochemical markers and medications were assessed 12 months pre- and post-surgery. Clinical outcomes, including hospital readmission, cardiovascular events and mortality were assessed following surgery.

RESULTS

During the 10-year study period, 129 patients underwent parathyroidectomy for SHPT (mean age 50.7 ± 15 years, 109 (85%) on dialysis). Significant immediate post-operative complications were seen in eight patients (6%), requiring admission to the intensive care unit (n = 6) or return to theatre (n = 2). Within the first 6 months, 24 patients (19%) required hospital readmission. Within 12 months post-parathyroidectomy, 100 (78%) and 103 patients (80%) experienced at least one episode of hypercalcaemia (corrected calcium >2.6 mmol/L) or hypocalcaemia (corrected calcium <2.1 mmol/L) respectively. Over a 12-month period there were six deaths (5%), and eight patients (6%) experienced a major cardiovascular event.

CONCLUSION

Significant fluctuations in serum calcium levels are common post-parathyroidectomy, however long-term morbidity and mortality in our cohort were lower than previously reported, highlighting that parathyroidectomy in a carefully selected cohort is safe for severe SHPT refractory to medical treatment. This article is protected by copyright. All rights reserved.

Evaluation of laboratory parameters and symptoms after parathyroidectomy in dialysis patients with secondary hyperparathyroidism

Objectives: The aim of the study was to evaluate the laboratory parameters and symptoms after parathyroidectomy (PTX) in dialysis patients with secondary hyperparathyroidism (SHPT), and to briefly analyze the different therapeutic effects of the three surgical methods.

Methods: A total of 182 dialysis patients who underwent PTX between February 2012 and January 2018 at the Second Affiliated Hospital of Soochow University were included in this study and followed for 12 months. Laboratory parameters such as calcium (Ca), phosphorus (P), alkaline phosphatase (ALP), and intact parathyroid hormone (iPTH) were measured before and after operation. According to the follow-up time and type of operation, we calculated the percentage of laboratory indicators reaching the recommended range of the KDIGO guidelines after surgery. We also analyzed the improvement of bone pain and pruritus, as well as surgical complications.

Results: After the operation, the levels of iPTH, Ca, and P decreased significantly at each time point. ALP increased at the first postoperative week and gradually decreased to normal range after 3 months. Symptoms, such as bone pain and pruritus, were significantly relieved. According to the follow-up time and three surgical methods (subtotal parathyroidectomy, total parathyroidectomy, total parathyroidectomy plus autologous transplantation), we found that the ratio of each laboratory parameter reaching the recommended range of KDIGO guidelines was significantly different.

Conclusion: PTX is a safe and effective therapy for treating SHPT that is refractory to medical therapies and accompanied by related signs and symptoms in dialysis patients. All three operative techniques were effective in controlling SHPT.

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.

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.

Total parathyroidectomy with forearm auto-transplantation improves the quality of life and reduces the recurrence of secondary hyperparathyroidism in chronic kidney disease patients

BACKGROUND

Our study aims to explore the effect of total parathyroidectomy (PTX) with forearm autotransplantation (FAT) on the quality of life and recurrence of secondary hyperparathyroidism (SHPT) in chronic kidney disease patients.

METHODS

A total of 104 chronic kidney disease patients with SHPT were enrolled and divided into the PTX (n = 62) and PTX + FAT (n = 42) groups. The operation efficacy was evaluated by analyzing preoperative and postoperative values, including levels of intact parathyroid hormone (iPTH), serum phosphorus, serum calcium, alkaline phosphatase (ALP), calcium-phosphorus product, signs and symptoms, and MOS 36-item short-form health survey (SF-36) scores. Moreover, complications and recurrences were followed up for 12 months after the operation. Binary logistic regression was to present the risk factors for the recurrence of chronic kidney disease patients with SHPT.

RESULTS

Compared with the preoperative values, the PTX and PTX + FAT groups showed decrease postoperative levels of iPTH, serum phosphorus, serum calcium, calcium-phosphorus product, bone pain, and skin pruritus at all time periods. The PTX and PTX + FAT groups demonstrated decreased ALP, fracture or deformity, and coronary artery calcification at 1 month, decreased short stature at 3 months after the operation but increased SF-36 score after operation. Compared with the PTX group, the level of iPTH decreased and the levels of serum calcium, calcium-phosphorus product increased at 3, 6, and 12 months after the operation in the PTX + FAT group. The levels of ALP, fracture or deformity, short stature, and SF-36 decreased separately at 1 week and 6 and 12 months after the operation, along with the decrease of coronary artery calcification and the recurrence rate, respectively, at 6 and 12 months after the operation in the PTX + FAT group when compared with those in the PTX group. Logistic regression analysis evidenced that the preoperative iPTH level, SF-36 score, and operation type were the risk factors for the recurrence of chronic kidney disease with SHPT.

CONCLUSION

Total PTX combined with FAT is more effective in improving the quality of life and reducing the recurrence of chronic kidney disease with SHPT than PTX alone.

Serum parathyroid hormone and alkaline phosphatase as predictors of calcium requirements after total parathyroidectomy for hypocalcemia in secondary hyperparathyroidism

BACKGROUND

To prevent hypocalcemia, this study examined the efficiency of a calcium supplement formula guided by predicted calcium requirement in patients with renal failure after parathyroidectomy with autotransplantation.

METHODS

In the first phase, a protocol was followed whereby intravenous calcium gluconate was repeatedly titrated based on serum calcium levels in 22 patients with parathyroidectomy with autotransplantation. In the second phase, the first equation protocol was applied in 74 patients with parathyroidectomy with autotransplantation and revised.

RESULTS

There is a significant correlation between the postoperative amount of calcium requirement and preoperative serum alkaline phosphatase level (r = 0.442; P < .001) and parathyroid hormone level (PTH; r = 0.889; P < .001). For prediction of insufficient calcium supplement, the cutoff point of PTH and alkaline phosphatase level values were calculated by receiver operating characteristic (ROC) curve analysis and modified equations were developed by regression analysis.

CONCLUSION

The preoperative PTH and alkaline phosphatase levels can predict postoperative calcium requirements, such that equations of calcium supplement allow the management of hypocalcemia efficiently in patients on dialysis after parathyroidectomy with autotransplantation.

Peripherally inserted central catheters for calcium requirements after successful parathyroidectomy: a comparison with centrally inserted catheters

BACKGROUND Intravenous calcium supplements are often required following parathyroidectomy to avoid postoperative hypocalcaemia. The aim of this study was to compare application effect of a femoral central venous catheter (CVC) and peripherally inserted central catheter (PICC) on intravenous calcium supplements after parathyroidectomy. METHODS We retrospectively reviewed the hospital records of 73 patients with secondary hyperparathyroidism who underwent a successful parathyroidectomy at the Huashan Hospital attached to Fudan University between 1 April 2011 and 1 February 2016. RESULTS Of the 73 study participants, 39 (53.4%) had a PICC and 34 (46.6%) had a CVC, respectively. Patients in the CVC group needed 6-7 days of intravenous calcium supplements, while patients in PICC group needed only 2-3 days to achieve normal serum calcium concentration (2.2-2.6 mmol/L). Furthermore, the duration of calcium supplementation was 71.62 ± 4.48 hours in PICC group and 100.4 ± 5.43 hours in CVC group (P < 0.05). Of the patients in PICC group, the incidence of catheter occlusion, operation failure and hypocalcaemia was 0%, which was significantly lower than those in CVC group (2.56%, 7.69% and 7.69%, respectively). CONCLUSIONS PICC is a safe and efficient alternative in contrast to CVC for providing venous access for calcium supplementation in surgical patients after parathyroidectomy.