Risk factors for severe hypocalcemia after parathyroidectomy in prevalent dialysis patients with secondary hyperparathyroidism

Identification of novel risk factors for postoperative severe hypocalcemia in patients with primary hyperparathyroidism undergoing parathyroidectomy: a case control study

BACKGROUND

Patients with primary hyperparathyroidism (PHPT) are at risk for severe hypocalcemia (SH) following parathyroidectomy (PTX), but limited data exist on the predictors of SH. We aimed to identify risk factors for early postoperative SH after PTX in patients with PHPT and to evaluate the predictive value of clinical parameters.

METHODS

A retrospective review of patients with PHPT who underwent PTX between January 2010 and December 2022 was performed. A total of 46 patients were included in the study, with 15 (32.6%) experiencing postoperative SH, 19 (41.3%) having calculi in the ureter or kidney, and 37 (80.4%) having osteoporosis. Patients were divided into SH and non-SH groups based on postoperative serum calcium levels. Preoperative biochemical indicators, bone turnover markers, and renal function parameters were analyzed and correlated with postoperative SH.

RESULTS

Statistically significant (P < 0.05) differences were found in preoperative serum calcium (serum Ca), intact parathyroid hormone, serum phosphorus (serum P), serum Ca/P, percentage decrease of serum Ca, total procollagen type 1 intact N-terminal propeptide, osteocalcin (OC), and alkaline phosphatase levels between the two groups. Multivariate analysis showed that serum P (odds ratio [OR] = 0.989; 95% confidence interval [95% CI] = 0.981-0.996; P = 0.003), serum Ca (OR = 0.007; 95% CI = 0.001-0.415; P = 0.017), serum Ca/P (OR = 0.135; 95% CI = 0.019-0.947; P = 0.044) and OC levels (OR = 1.012; 95% CI = 1.001-1.024; P = 0.036) were predictors of early postoperative SH. The receiver operating characteristic curve analysis revealed that serum P (area under the curve [AUC] = 0.859, P < 0.001), serum Ca/P (AUC = 0.735, P = 0.010) and OC (AUC = 0.729, P = 0.013) had high sensitivity and specificity.

CONCLUSION

Preoperative serum P, serum Ca/P and osteocalcin levels may identify patients with PHPT at risk for early postoperative SH after PTX.

A novel index to predict postoperative hypocalcemia in primary hyperparathyroidism

BAKGROUND

Vitamin D (Vit D) deficiency is common in patients with hyperparathyroidism, but the importance of replacement before surgery is controversial. It can be predicted that hypocalcemia risk will be higher in patients with high bone turnover.

AIM

In this study, the effect of preoperative ALP/Vit D ratio on postoperative hypocalcemia was investigated.

METHODS

Among the primary hyperparathyroidism cases who were operated between 2015 and 2022, 158 patients with complete data were included in the study. Preoperative laboratory results, radiological images, and pathology reports of the patients were evaluated retrospectively. The cross-sectional value of the ALP/Vit D value predicting hypocalcemia was calculated. The effect of these parameters on postoperative hypocalcemia was investigated.

RESULTS

The mean age of our patients was 54 (21-81 years). When factors affecting postoperative hypocalcemia were evaluated by univariable analysis, Vit D deficiency and insufficiency (p < 0.001), ALP (p < 0.001), ALP/Vit D ratio (p < 0.001), and T score (p = 0.026) found to be factors affecting postoperative hypocalcemia. In multivariate analysis, the ALP/Vit D ratio was found to be an independent variable in predicting hypocalcemia. It was found that hypocalcemia was 45 times more common in patients with ALP/Vit D > 6.34 (p < 0.001). ALP/Vit D ratio predicts patients who will develop postoperative hypocalcemia with 87.2% sensitivity and 87.1% specificity.

CONCLUSIONS

Vit D deficiency increases the risk of postoperative hypocalcemia, but it is not sufficient alone to predict it. The risk increases more in patients with high bone turnover. The preoperative ALP/Vit D ratio is the strongest predictor of postoperative hypocalcemia risk.

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.

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.

[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.

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 &lt;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 &lt; 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 &gt; 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.

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%.

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.

Risk factors for hypocalcemia in dialysis patients with refractory secondary hyperparathyroidism after parathyroidectomy: a meta-analysis

Objective

Hypocalcemia after parathyroidectomy (PTX) results in tetany, diarrhea, cardiac arrhythmia, and even sudden death. However, a meta-analysis or systematic evaluation of risk factors with the occurrence and development of hypocalcemia in patients with secondary hyperparathyroidism (SHPT) after PTX has never been performed.

Methods

A thorough search of electronic databases, including PubMed, Web of Science, the Cochrane Library, and EMBASE, was performed to retrieve relevant studies from database inception to June 2021. Quality of the included studies was assessed by two independent reviewers using the Newcastle–Ottawa Scale. Review Manager 5.3 and Stata 16.0 were used for meta-analysis. The random-effects model was adopted to calculate the 95% CIs (I²> 50% or p < 0.05) of the combined effect size and the corresponding homogeneous data. Otherwise, a fixed-effects model was used.

Results

Thirteen studies including 2990 participants who met the inclusion criteria were enrolled in the present meta-analysis. The overall quality of the enrolled studies had a score of >7 points. Risk factors significantly related to hypocalcemia in patients with SHPT after PTX were preoperative serum calcium (OR 0.19, 95%CI 0.11–0.31), preoperative alkaline phosphatase (ALP) (OR 1.01, 95% CI 1.01–1.02), and preoperative intact parathyroid hormone (iPTH) (OR 1.38, 95%CI 1.20–1.58). Meanwhile, age (OR 0.97, 95%CI 0.87–1.10) was not significantly correlated with hypocalcemia after PTX.

Conclusions

Based on the current evidence, preoperative serum calcium, preoperative ALP, and preoperative iPTH were significant predictors of hypocalcemia in patients with SHPT after PTX. More attention should be given to patients with these risk factors for the prevention of postoperative hypocalcemia.

A single-center experience of parathyroidectomy in 1500 cases for secondary hyperparathyroidism: a retrospective study

Background

Chronic kidney disease (CKD) is a global public health problem. With the deterioration of renal function, a certain proportion of CKD patients enter the uremic stage, and secondary hyperparathyroidism (SHPT) becomes a challenge. For refractory hyperparathyroidism, parathyroidectomy (PTX) plays a key role in reducing mortality and improving prognosis. Nevertheless, no consensus has been reached on the optimal surgical method. We aimed to provide evidence for the effectiveness of surgical treatment by summarizing the experience from our center.

Methods

Clinical data from 1500 patients undergoing parathyroidectomy were recorded, which included 1419 patients in a total parathyroidectomy without autotransplantation (tPTX) group, 54 patients in a total parathyroidectomy plus autotransplantation (tPTX + AT) group, and 27 patients in the other group. Perioperative basic data, intact parathyroid hormone (i-PTH) levels, serum calcium levels, serum phosphorus levels, pathological reports, coexisting thyroid diseases, short-term outcomes and complications were analyzed. Moreover, postoperative complications were compared between the tPTX and tPTX + AT groups.

Results

Parathyroid hormone, serum calcium and phosphorus levels decreased significantly post-surgery. Two patients died during the perioperative period. As the two most common complications, the incidences of severe hypocalcemia and hyperkalemia were 36.20% (543 cases) and 24.60% (369 cases), respectively. Pre-iPTH levels (OR = 1.001, 95% CI: 1.001–1.001, p < 0.01), serum alkaline phosphatase (ALP) levels (OR = 1.002, 95% CI: 1.001–1.002, p < 0.01) and the mass of excised parathyroid gland (OR = 3.06, 95% CI: 1.24–7.55, p = 0.02) were positively associated with postoperative severe hypocalcemia, while age and serum calcium were negatively associated with it. Pathological reports of resected parathyroid and thyroid glands indicated that 96.49% had parathyroid nodular hyperplasia, 13.45% had thyroid nodular hyperplasia, and 4.08% had thyroid papillary carcinoma.

Conclusions

Parathyroidectomy is a safe and effective treatment for refractory secondary hyperparathyroidism. Severe hypocalcemia is the main complication, and coexistent thyroid diseases should never be neglected.

Construction and validation of a predictive model for hypocalcemia after parathyroidectomy in patients with secondary hyperparathyroidism

OBJECTIVE

We aimed to construct and validate a predictive model for the risk of hypocalcemia following parathyroidectomy (PTX) for the treatment of secondary(renal) hyperparathyroidism (SHPT).

METHODS

Information regarding patients with SHPT who underwent PTX between January 2019 and April 2022 was collected retrospectively. Univariate and multivariate logistic regression analyses were used to identify independent risk factors for hypocalcemia following PTX and to construct predictive models. The areas under the receiver operating characteristic curve (AUC), the calibration curve, and the clinical decision curve (decision curve analysis, DCA) were used to assess the discrimination, calibration, and level of clinical benefit obtained using the predictive models.

RESULTS

We studied 238 patients who were randomly allocated in a 7:3 ratio to a training group (n=166) and a test group (n=72). Univariate and multivariate logistic regression analyses were performed, in which three variables (the circulating parathyroid hormone (PTH) and Ca concentrations, and alkaline phosphatase (ALP) activity) were interrogated for possible roles as independent risk factors for hypocalcemia in patients with SHPT who undergo PTX, and used to construct predictive models. The AUCs for the constructed models were high for both the training (0.903) and test (0.948) groups. The calibration curve showed good agreement between the incidence of postoperative hypocalcemia estimated using the predictive model and the actual incidence. The DCA curve indicated that the predictive model performed well.

CONCLUSION

A predictive model constructed using a combination of preoperative PTH, Ca, and ALP may represent a useful means of identifying patients with SHPT at high risk of developing hypocalcemia following PTX in clinical practice.

Use of 99mTc-sestamibi SPECT/CT imaging in predicting the degree of pathological hyperplasia of the parathyroid gland: semi-quantitative analysis

Background

Previous studies have demonstrated that ^99mTc-sestamibi (^99mTc-MIBI) Single-Photon Emission Computed Tomography/ Computed Tomography (SPECT/CT) imaging is an effective isotopic technique for locating the parathyroid in secondary hyperparathyroidism (SHPT). This study aimed to explore further the correlation between ^99mTc-MIBI SPECT/CT imaging and SHPT to demonstrate the value of ^99mTc-MIBI SPECT/CT in evaluating the degree of pathological hyperplasia of the parathyroid gland (PG).

Methods

The demographics, surgical records, and follow-up information of 91 patients were recorded and analyzed. A total of 216 paraffin-embedded PGs of 54 patients were obtained and analyzed.

Results

Patients with ^99mTc-MIBI negative PG(s) had significantly lower preoperative serum phosphorus and higher serum calcium levels at 6 months postoperatively compared to those with ^99mTc-MIBI positive PG(s) (P<0.05). We also found a higher total uptake ratio of the region of interest (URRI) and higher URRI max in the hypocalcemia group than in the non-hypocalcemia group. Both URRI total (P=0.003) and URRI max (P=0.028) were independent risk factors for hypocalcemia 6 months postoperatively. The URRI values of the PGs were significantly positively correlated with glandular weight (R²=0.343, P<0.001), glandular volume (R²=0.240, P<0.001), and degree of pathological hyperplasia (P<0.001). However, the URRI value of the PGs exhibited a notably weak correlation with proliferating cell nuclear antigen (PCNA) (R²=0.035, P=0.006). The area under the receiver operating characteristic curve showed a URRI evaluative value of 0.771 for diffuse and nodular types in 216 PGs (P<0.001). We further evaluated 167 nodular-type PGs, distinguishing between nodular hyperplasia and a single nodule; the URRI evaluative value reached 0.819, which was higher than the volume or weight (P<0.001).

Conclusions

The ^99mTc-MIBI SPECT/CT scintigraphy results were related to serum calcium levels at 6 months after total parathyroidectomy with autotransplantation (TPTX+AT), suggesting the occurrence of hypocalcemia (6 months after TPTX+AT). More importantly, this technique effectively evaluated the pathological hyperplasia of PGs preoperatively, and therefore, could assist surgeons in selecting the PGs with the lowest degree of hyperplasia intraoperatively.

Risk Factors for Severe Hypocalcemia in Patients with Secondary Hyperparathyroidism after Total Parathyroidectomy

BACKGROUND

Hypocalcemia is the most common complication of total parathyroidectomy in secondary hyperparathyroidism (SHPT) and is associated with adverse consequences such as spasms, epilepsy, and arrhythmia and even death if the serum calcium level decreases rapidly. Previous studies have identified several risk factors for postoperative severe hypocalcemia (SH) in patients with SHPT, but the sample sizes were small and thus the results may not be reliable.

OBJECTIVES

This study was performed to investigate the risk factors for SH after total parathyroidectomy without autotransplantation (tPTX) in a large sample of patients with uremic hyperparathyroidism.

METHODS

We retrospectively investigated the records of 1,095 patients with SHPT treated with tPTX between January 2008 and December 2018. Based on the postoperative serum calcium concentration, the patients were grouped into SH and non-SH groups. The clinical characteristics and biochemical results were analyzed, and binary logistic regression analysis was used to identify the risk factors for SH.

RESULTS

After surgery, 25.9% of the patients developed SH. Age, diastolic blood pressure (DBP), heart rate, frequency of bone pain, weight of resected glands, preoperative serum calcium, intact parathyroid hormone (iPTH), alkaline phosphatase (ALP), and hemoglobin levels differed between the two groups. Binary logistic regression analyses identified preoperative serum calcium, iPTH, and ALP levels as independent predictors of SH after surgery.

CONCLUSIONS

The preoperative serum calcium, iPTH, and ALP levels can be used to assess the risk of postoperative SH in patients with SHPT. Such patients should thus be monitored closely in order to initiate prompt interventions to avoid SH.

Risk factors predicting severe hypocalcemia after total parathyroidectomy without autotransplantation in patients with secondary hyperparathyroidism

Objective

This study was performed to investigate the risk factors for severe hypocalcemia (SH) after total parathyroidectomy without autotransplantation (TPTX) in patients with secondary hyperparathyroidism.

Methods

We retrospectively analyzed the records of 136 patients with secondary hyperparathyroidism treated by TPTX. The patients were categorized as having SH or non-SH based on their postoperative blood calcium concentration. The risk factors for SH were identified by comparing the clinical characteristics between the two groups and by performing multiple logistic regression analyses.

Results

After surgery, 46.0% of the patients had hypocalcemia and 31.7% had SH. Evidence of renal osteodystrophy on lumbar radiographs and the serum concentrations of intact parathyroid hormone (iPTH), calcium, and alkaline phosphatase (ALP) were different between the two groups. The SH group had higher preoperative iPTH and ALP concentrations than the non-SH group. In addition, more patients with SH showed renal osteodystrophy. Logistic regression analyses indicated that preoperative hypocalcemia and a high ALP concentration were independent predictors of SH.

Conclusion

Preoperative hypocalcemia and a high ALP concentration were identified as risk factors for SH following TPTX.

Hypocalcemia after ultrasound-guided microwave ablation and total parathyroidectomy for secondary hyperparathyroidism: a retrospective study

OBJECTIVE

To compare the postoperative hypocalcemia between ultrasound-guided microwave ablation (MWA) and total parathyroidectomy (TPTX) for secondary hyperparathyroidism (SHPT).

METHODS

The retrospective study reviewed 286 SHPT patients (171 received MWA and 115 underwent TPTX) between March 2018 and May 2019. Propensity-score matching was used to assemble a cohort of patients with similar baseline characteristics. A total of 184 SHPT patients (92 in each group) were finally enrolled, the occurrence and prognosis of postoperative hypocalcemia were compared. And the risk factors associated with severe hypocalcemia (SH) in each group were analyzed.

RESULTS

Hypocalcemia encountered in 95cases (49 in the MWA group and 46 in the TPTX group). SH occurred in 76 cases (40 in the MWA group and 36 in the TPTX group). There were no statistically significant differences in the detection time, incidence, minimum value of serum calcium and symptomatic hypocalcemia between MWA and TPTX group (all p values > 0.05). Of patients developing hypocalcemia, serum calcium did not recover to normal range in 5 cases (10.2%) in the MWA group, while 13 cases (28.3%) were still hypocalcemia at 6 months follow-up in TPTX group (p = 0.035). The time to recovery from hypocalcemia in the TPTX group (mean 30 days, range 3-180 days) was longer than the WA group (mean 14 days, range 3-126 days) (p = 0.000). High serum alkaline phosphatase (ALP) level and low serum calcium level were the main risk factors of postoperative SH.

CONCLUSION

There was no difference in hypocalcemia between MWA and TPTX group. Hypocalcemia in the TPTX group might need a longer time to recover.

Risk Factors of Severe Hypocalcemia After US-Guided Percutaneous Microwave Ablation of the Parathyroid Gland in Patients with Secondary Hyperparathyroidism

Our aim was to identify potential risk factors associated with severe hypocalcemia (SH) after microwave ablation (MWA) in patients with secondary hyperparathyroidism (SHPT). This retrospective cross-sectional study enrolled 204 consecutive patients (with 387 parathyroid glands) who underwent MWA between July 2015 and May 2018. Clinical parameters, laboratory indices, and parathyroid gland characteristics were analyzed to assess risk factors associated with SH after MWA. SH was defined as serum calcium level lower than 1.875 mmol/L (7.5 mg/dL) after MWA. Two models (I and II) for pre-MWA and post-MWA prediction were established, respectively. In accordance with the KDIGO guidelines, the target value for intact parathyroid hormone (iPTH) less than 300 pg/mL within 7 days after MWA was considered as a successful procedure. The success rate of MWA was 71.6% (146/204). The incidence of hypocalcemia and SH after MWA was 35.8% and 22.06%, respectively. The pre-MWA prediction models I and II showed that high pre-MWA iPTH, a dramatic reduction in iPTH, low pre-MWA serum calcium, multiple ablated gland, and lack of pruritus symptoms were risk factors for developing SH. The accuracy (82.23% versus 83.25% in models I and II, respectively), sensitivity (34.88% versus 44.19%), specificity (95.45% versus 94.59%), positive predictive value (PPV) (68.18% versus 70.37%), and negative predictive value (NPV) (84% versus 85.37%) of both models were promising. The logistic regression fitting of the nomograms showed high prediction efficiency (0.845 and 0.863). High pre-MWA iPTH, dramatic reductions in iPTH, low pre-MWA serum calcium, multiple gland ablation, and no pruritus symptoms were predictors of SH. © 2019 American Society for Bone and Mineral Research.

Predictors of early postoperative hypocalcemia after total parathyroidectomy in renal hyperparathyroidism

Purpose

Patients with secondary hyperparathyroidism are at high risk for developing postoperative hypocalcemia. However, there are limited data regarding predictors of postoperative hypocalcemia in renal failure patient with secondary hyperparathyroidism. This study aimed to determine the clinical presentations of renal hyperparathyroidism and the predictors of early postoperative hypocalcemia after total parathyroidectomy.

Methods

Data of patients with renal hyperparathyroidism who underwent total parathyroidectomy between January 2007 to December 2014 were reviewed retrospectively. Patients were divided into 2 cohort groups according to their serum calcium levels within 24 hours of parathyroidectomy: the hypocalcemia group (calcium levels of 2 mmol/L or less), and the normocalcemia group (calcium levels more than 2 mmol/L). With the use of multivariable logistic regression analyses, the predictors of early postoperative hypocalcemia after total parathyroidectomy in patients with renal hyperparathyroidism were investigated.

Results

Among 68 patients, 56 patients (82.4%) were symptomatic preoperatively. Fifty patients (73.5%) presented with bone pain and 14 patients (20.6%) had muscle weakness. Early postoperative hypocalcemia occurred in 25 patients (36.8%). Preoperative alkaline phosphatase level was the predictor of early postoperative hypocalcemia (adjusted odds ratio, 1.004; 95% confidence interval, 1.001–1.006; P = 0.002).

Conclusion

Results from our study show that most of the patients with renal hyperparathyroidism were symptomatic preoperatively and the most common clinical presentations were bone pain and muscle weakness. The significant predictor of early postoperative hypocalcemia after total parathyroidectomy was the preoperative alkaline phosphatase levels.

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.

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.

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.

Risk factors for severe hypocalcemia after parathyroidectomy in dialysis patients with secondary hyperparathyroidism

Severe hypocalcemia (SH) is a common and serious complication in dialysis patients with secondary hyperparathyroidism (SHPT) after parathyroidectomy (PTX). The aim is to explore the risk predictors of SH in post-PTX dialysis ESRD patients with SHPT. 129 consecutive dialysis patients with SHPT underwent PTX were retrospectively reviewed. A total of 22 clinical parameters were included in the study. SH was defined as the minimum values of serum calcium lower than 1.875 mmol/L (7.5 mg/dL) after surgery. Univariate analysis showed that pruritus, lumbar X-ray changes of renal osteodystrophy, pre- and post-operative intact parathyroid hormone (iPTH), Calcium, alkaline phosphatase, and gland mass were significantly different between SH and non-SH groups. In the multivariate logistic regression model, the pre-operative serum iPTH, calcium, and pruritus were independent risk predictors of SH. AUCs for pre-operative serum iPTH, calcium and pruritus were 0.810, 0.714 and 0.591, respectively. Patients with higher level of pre-operative serum iPTH, lower level of serum calcium and with no/mild symptoms of pruritus are at greater risk of developing SH after PTX.

Risk Factors for Elevated Preoperative Alkaline Phosphatase in Patients with Refractory Secondary Hyperparathyroidism

Elevated preoperative levels of alkaline phosphatase (ALP) in patients with refractory secondary hyperparathyroidism are correlated with postoperative hypocalcemia and mortality. The aim of this study was to identify the predictors of preoperative ALP in patients with secondary hyperparathyroidism. From April 2012 to December 2015, 220 patients with refractory secondary hyperparathyroidism undergoing total parathyroidectomy without autotransplantation were reviewed. A total of 164 patients presented with elevated preoperative ALP. Univariate analysis showed that patients with elevated ALP were significantly younger. The elevated ALP group had significantly higher levels of preoperative parathyroid hormone (PTH), lower preoperative serum calcium, higher preoperative phosphorus, lower postoperative hypocalcemia, and a longer hospital stay. Logistic regression analysis showed that elevated preoperative PTH was a significant independent risk factor for elevated preoperative ALP (P = 0.000), and its value of 1624 pg/mL was the optimal cutoff point. Factors predictive of elevated preoperative ALP in patients with secondary hyperparathyroidism include preoperative PTH. Earlier surgery, aggressive calcium supplementation, and more careful or aggressive postoperative care for high-risk patients are needed.

Parathyroidectomy for the treatment of hyperparathyroidism: Thirty-day morbidity and mortality

OBJECTIVES/HYPOTHESIS

Evaluate morbidity and mortality rates for patients with different levels of hyperparathyroidism (HPT) undergoing parathyroidectomy (PTX), specifically comparing primary hyperparathyroidism to secondary and tertiary hyperparathyroidism. Assess predictive factors of increased morbidity and mortality.

STUDY DESIGN

Retrospective national database review.

METHODS

Patients undergoing PTX, defined by Current Procedural Terminology codes 60500, 60502, 60505, for the treatment of HPT, were identified in the American College of Surgeons National Surgical Quality Improvement Program database between 2006 and 2014. Incidence of morbidity and mortality was calculated for primary, secondary, and tertiary HPT. A t test, analysis of variance, and χ² analyses were used to assess preoperative characteristics among the three groups.

RESULTS

A total of 21,267 patients were included in the analysis. There was an overall 7.2% morbidity and mortality rate, including 45 (0.21%) deaths, a 1.8% readmission rate, and a 1.9% reoperation rate, but morbidity and mortality rates were widely divergent when comparing primary to secondary and tertiary HPT. PTX resulted in a 4.9% morbidity and mortality rate for primary HPT (n = 14,500), 26.8% morbidity and mortality rate for secondary HPT (n = 1661), and 21.8% morbidity and mortality rate for tertiary HPT (n = 588). The primary reason for readmission was hypocalcemia (18.3%). Hematoma (7.2%) and postoperative hemorrhage (3.3%) were the two most common causes of reoperation. Elevated preoperative serum creatinine, alkaline phosphatase, and hypertension resulted in a higher rate of complications after PTX (P < .0001).

CONCLUSIONS

Although surgery for primary HPT is an extremely common and safe procedure with minimal morbidity and mortality rates, PTX for secondary and tertiary HPT has significantly higher rates of morbidity and mortality, requiring special attention in the postoperative period. Predictive factors of poor outcomes include hypertension, elevated creatinine, and elevated alkaline phosphatase.

LEVEL OF EVIDENCE

4. Laryngoscope, 128:528-533, 2018.

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.

Survival after parathyroidectomy in chronic hemodialysis patients with severe secondary hyperparathyroidism

INTRODUCTION

The life for end-stage renal disease patients has remarkably improved in the last years. Although mineral and bone disorders remain as unsolved complication, in severe secondary hyperparathyroidism (sHPT), the ultimate treatment is parathyroidectomy (PTX). It is an old treatment, but there are still insufficient data regarding survival after PTX. The study goals were to compare 2-year mortality and morbidity after PTX in surgically versus medically treated sHPT and to compare the efficacy and safety in subtotal versus total PTX in a cohort of patients receiving hemodialysis (HD).

METHODS

This prospective, longitudinal study was carried out on a cohort of chronic HD patients with severe sHPT (iPTH over 700 pg/ml). Among the overall HD population, 26 patients underwent PTX. This group was compared to a control group treated with specific drugs. Laboratory parameters, specific symptoms and mortality were registered after 24 months of follow-up for each group. The subgroups of subtotal and total PTX patients were also compared.

RESULTS

All average values of mineral markers were significantly reduced after PTX, as a proof that surgical treatment was effective. The reduction in mineral markers and the improvement in symptoms and mortality rates were similar after total and subtotal PTX. Bone pain was significantly lower in patients after PTX than in those drug treated (p = 0.0005), but not muscle weakness and itching. Survival at 2 years was better in patients surgically treated (PTX) despite significantly higher mean baseline values of iPTH, Ca and ALP compared to patients medically treated (p = 0.03).

CONCLUSIONS

We compared clinical and laboratory outcomes in HD patients with severe sHPT. Mortality, bone pain and mineral markers were improved by PTX. Total and subtotal PTX had similar clinical outcomes.