Time to parathyroid function recovery in patients with protracted hypoparathyroidism after total thyroidectomy

Risk factors of transient and permanent hypoparathyroidism after thyroidectomy: a systematic review and meta-analysis

BACKGROUND

Postoperative hypoparathyroidism (hypoPT) is a common complication following thyroid surgery. However, current research findings on the risk factors for post-thyroid surgery hypoPT are not entirely consistent, and the same risk factors may have different impacts on transient and permanent hypoPT. Therefore, there is a need for a comprehensive study to summarize and explore the risk factors for both transient and permanent hypoPT after thyroid surgery.

MATERIALS AND METHODS

Two databases (PubMed and Embase) were searched from inception to 2024. The Newcastle-Ottawa Scale was used to rate study quality. Pooled odds ratios were used to calculate the relationship of each risk factor with transient and permanent hypoPT. Subgroup analyses were conducted for hypoPT with different definition-time (6 or 12 months). Publication bias was assessed using Begg's test and Egger's test.

RESULTS

A total of 19 risk factors from the 93 studies were included in the analysis. Among them, sex and parathyroid autotransplantation were the most frequently reported risk factors. Meta-analysis demonstrated that sex (female vs. male), cN stage, central neck dissection, lateral neck dissection, extent of central neck dissection (bilateral vs. unilateral), surgery [total thyroidectomy (TT) vs. lobectomy], surgery type (TT vs. sub-TT), incidental parathyroidectomy, and pathology (cancer vs. benign) were significantly associated with transient and permanent hypoPT. Preoperative calcium and parathyroid autotransplantation were only identified as risk factors for transient hypoPT, while preoperative PTH was a protective factor. Additionally, node metastasis and parathyroid in specimen were associated with permanent hypoPT.

CONCLUSION

The highest risk of hypoPT occurs in female thyroid cancer patients with lymph node metastasis undergoing TT combined with neck dissection. The key to preventing postoperative hypoPT lies in the selection of surgical approach and intraoperative protection.

The effect of carbon nanoparticles vs. immune colloidal gold technique test strips on parathyroid protection in total thyroidectomy: A randomized clinical trial study

BACKGROUND

The long-term effect of intraoperative usage of carbon nanoparticles (CN) and parathyroid hormone (PTH) test strip using immune colloidal gold technique (ICGT) is unclear. This study aims to compare the effect of intraoperative usage of CN and ICGT test strips on PG function.

METHODS

This randomized clinical study involved adult patients who underwent total thyroidectomy. They were randomly allocated into three groups (control, CN, and ICGT group). Clinical data were analyzed.

RESULTS

Each group involved 98 patients. Serum calcium and PTH concentrations at 24 h postoperatively (PTH24h) were higher in CN group. The parathyroid function recovered quicker in CN group. Use of CN increased in situ PG preservation and PTH24h. Mediation analysis indicated that 23.05% of the total effect of CN on PTH24h was attributed to PGRIS.

CONCLUSION

CN holds promise to improve in situ PG preservation and protect PG vasculature, thereby reducing the incidence of early hypoparathyroidism. The value of ICGT test strips for PG protection is dubious.

Effects of magnesium supplementation on post-thyroidectomy hypocalcemia: a prospective single-center study

BACKGROUND

Severe and/or symptomatic hypocalcemia due to hypoparathyroidism is the main contraindication for discharge in patients who have undergone thyroid surgery. Hypomagnesemia may contribute to the onset of hypoparathyroidism and is frequently observed after thyroid surgery in hypocalcemic patients. The impact of prophylactic and postoperative Magnesium supplementation on postoperative hypocalcemia and hypomagnesemia was prospectively evaluated by comparing patients undergoing prophylactic supplementation to a control group of patients who had only received magnesium after evidence of postoperative hypomagnesemia.

METHODS

One hundred and twenty patients who underwent a total thyroidectomy participated in the study. Seventy-three patients were included in the study group, 47 in the control group. Prior to surgery, patients in the study group were given magnesium orally for 5 days; postoperatively, calcium and magnesium was administered to all patients who displayed hypocalcemia and hypomagnesemia.

RESULTS

Postoperative biochemical hypocalcemia (serum calcium <8.5 mg/dL, regardless of its clinical severity) was found in 60 patients (50%) on D1 and in 58 patients (48.4%) on D2. Among hypocalcemic patients, hypomagnesemia was recorded in 29 at D1 (48%), and in 46 at D2 (79%). A significant positive correlation was found between magnesium, calcium, and parathyroid hormone in the first two postoperative days, while a significant inverse correlation occurred for these same parameters and length of hospital stay (P<0.001). One hundred and five patients (87.5%) were discharged as expected on the second postoperative day (65 in the study group, 40 in the control group, P=0.724), whereas 15 patients (12.5%) required prolonged hospitalization (eight in the study group, seven in the control group, P=0.721). The Study group only showed significantly higher magnesium levels on the first postoperative day (P=0.03).

CONCLUSIONS

Although magnesium and calcium levels showed the same trend after thyroidectomy, neither Magnesium prophylaxis nor Magnesium treatment influenced the clinical course of postoperative hypocalcemia.

Hypoparathyroidism and mortality after total thyroidectomy: A nationwide matched cohort study

OBJECTIVE

Total thyroidectomy (TT) carries a risk of hypoparathyroidism (hypoPT). Recently, hypoPT has been associated with higher overall mortality rates. We aimed to evaluate the frequency of hypoPT and mortality in patients undergoing TT in Denmark covering 20 years.

DESIGN

Retrospective Cohort study.

PATIENTS AND MEASUREMENTS

Using population-based registries, we identified all Danish individuals who had undergone TT between January 1998 and December 2017. We included a comparison cohort by randomly selecting 10 citizens for each patient, matched on sex and birth year. HypoPT was defined as treatment with active vitamin D after 12 months postoperatively. We used cumulative incidence to calculate risks and Cox regression to compare the rate of mortality between patients and the comparison cohort. We evaluated patients in different comorbidity groups using the Charlson Comorbidity Index and by different indications for surgery.

RESULTS

7912 patients underwent TT in the period. The prevalence of hypoPT in the study period was 16.6%, 12 months postoperatively. After adjusting for potential confounders the risk of death due to any causes (hazard ratio; 95% confidence intervals) following TT was significantly increased (1.34; 1.15-1.56) for patients who developed hypoPT. However, subgroup analysis revealed mortality was only increased in malignancy cases (2.48; 1.99-3.10) whereas mortality was not increased when surgery was due to benign indications such as goitre (0.88; 0.68-1.15) or thyrotoxicosis (0.86; 0.57-1.28).

CONCLUSIONS

The use of active vitamin D for hypoPT was prevalent one year after TT. Patients with hypoPT did not have an increased risk of mortality following TT unless the indication was due to malignancy.

Dynamics of PTH levels in the development of post-operative hypoparathyroidism

BACKGROUND

Post-operative hypoparathyroidism is the most frequent complication after total thyroidectomy. The identification of preoperative predictors could be helpful to identify patients at risk. This study aimed to evaluate the potential influence of preoperative PTH levels and their perioperative dynamics as a predictor of transient, protracted, and permanent post-operative hypoparathyroidism.

METHODS

A prospective, observational study that includes 100 patients who underwent total thyroidectomy between September 2018 and September 2020.

RESULTS

Transient hypoparathyroidism was present in 42% (42/100) of patients, 11% (11/100) developed protracted hypoparathyroidism, and 5% (5/100) permanent hypoparathyroidism. Patients who presented protracted hypoparathyroidism had higher preoperative PTH levels. The protracted and permanent hypoparathyroidism rate was higher in groups with greater preoperative PTH [0% group 1 (<40 pg/mL) vs. 5.7% group 2 (40-70 pg/mL) vs. 21.6% group 3 (>70 pg/mL); p = 0.03] and (0 vs. 8.3 vs. 20%; p = 0.442), respectively. The rate of protracted and permanent hypoparathyroidism was higher in patients with PTH at 24 h lower than 6.6 pg/mL and whose percentage of PTH decline was higher than 90%. The rate of transient hypoparathyroidism was higher in patients who showed a PTH decline rate of more than 60%. The percentage of PTH increase one week after surgery in patients with permanent hypoparathyroidism was significantly lower.

CONCLUSION

The prevalence of protracted hypoparathyroidism was higher in groups with higher preoperative PTH levels. PTH levels 24 h after surgery lower than 6.6 pg/mL and a decline of more than 90% predict protracted and permanent hypoparathyroidism. The percentage of PTH increase a week after surgery could predict permanent hypoparathyroidism.

Investigating the optimal parathyroid autotransplantation strategy in transareolar endoscopic thyroidectomy: A retrospective cohort study

BACKGROUND

There is ongoing debate about whether intraoperative parathyroid autotransplantation effectively prevents permanent hypoparathyroidism after thyroidectomy. This study aims to examine its impact on postoperative parathyroid function and determine the best autotransplantation strategy.

METHODS

A retrospective analysis was conducted on 194 patients who underwent total thyroidectomy with central lymph node dissection (CLND) for papillary thyroid carcinoma (PTC). Patients were divided into four groups based on the number of parathyroid autotransplants during surgery: Group 1 (none, n = 43), Group 2 (1 transplant, n = 60), Group 3 (2 transplants, n = 67), and Group 4 (3 transplants, n = 24). Various clinical parameters were collected and compared among the groups.

RESULTS

Parathyroid autotransplantation was identified as a risk factor for temporary hypoparathyroidism (OR: 1.74; 95% CI: 1.27-2.39, P = 0.001) and a protective factor for permanent hypoparathyroidism (OR: 0.27; 95% CI: 0.14-0.55, P < 0.001). At 12 months postoperative, systemic parathyroid hormone (PTH) levels increased progressively from Groups 1 to 4, with significant differences observed only between Group 1 and Group 2 (P < 0.02). Difference values in systemic PTH levels between Month 1 and Day 1 postoperative increased progressively from Groups 1 to 4, with statistically significant differences observed between adjacent groups (P < 0.02). The number of dissected positive lymph nodes increased progressively across the four groups, showing statistical differences (P < 0.02).

CONCLUSION

Parathyroid autotransplantation can prevent permanent hypoparathyroidism. Additionally, we recommend preserving parathyroids in situ whenever possible. If autotransplantation is required, it should involve no more than two glands.

Hypoparathyroidism-related health care utilization and expenditure during the first postoperative year after total thyroidectomy for cancer: a comprehensive national cohort study

Objectives

Hypoparathyroidism is the most common complication of total thyroidectomy for cancer, and requires calcium and/or vitamin D supplementation for an unpredictable period of time. The additional cost associated with this complication has not hitherto been assessed. The aim of this study was to assess the economic burden of postoperative hypoparathyroidism after total thyroidectomy for cancer in France.

Methods

Based on the French national cancer cohort, which extracts data from the French National Health Data System (SNDS), all adult patients who underwent a total thyroidectomy for cancer in France between 2011 and 2015 were identified, and their healthcare resource use during the first postoperative year was compared according to whether they were treated postoperatively with calcium and/or vitamin D or not. Univariate and multivariate cost analyses were performed with the non-parametric Wilcoxon test and generalized linear model (gamma distribution and log link), respectively.

Results

Among the 31,175 patients analyzed (75% female, median age: 52y), 13,247 (42%) started calcium and/or vitamin D supplementation within the first postoperative month, and 2,855 patients (9.1%) were still treated at 1 year. Over the first postoperative year, mean overall and specific health expenditures were significantly higher for treated patients than for untreated patients: €7,233 vs €6,934 per patient (p<0.0001) and €478.6 vs €332.7 per patient (p<0.0001), respectively. After adjusting for age, gender, Charlson Comorbidity index, ecological deprivation index, types of thyroid resection, lymph node dissection and complications, year and region, the incremental cost of overall health care utilization was €142 (p<0.004).

Conclusion

Our study found a significant additional cost in respect of health expenditures for patients who had hypoparathyroidism after thyroidectomy for cancer, over the first postoperative year. Five-year follow-up is planned to assess the impact of more severe long-term complications on costs.

The safety, benefits and future development of overnight and outpatient thyroidectomy

With the development of medical care, the safety of thyroidectomy is improving year by year. Due to economic benefits and other advantages of the overnight and outpatient thyroidectomy, more and more patients and medical institutions have favored overnight and outpatient thyroidectomy, and its proportion in thyroidectomy has increased year by year. However, overnight and outpatient thyroidectomy still faces many challenges and remains to be improved. In this review, we focused on the recent progress and the relevant clinical features of overnight and outpatient thyroidectomy, including its safety, economic benefits, etc., which may bring valuable clues and information for further improvements of patient benefits and promotions of overnight or outpatient thyroidectomy in the future.

Etiology and Pathophysiology of Hypoparathyroidism: A Narrative Review

The approach utilized a systematic review of the medical literature executed with specifically designed criteria that focused on the etiologies and pathogenesis of hypoparathyroidism. Enhanced attention by endocrine surgeons to new knowledge about parathyroid gland viability are reviewed along with the role of intraoperative parathyroid hormone (ioPTH) monitoring during and after neck surgery. Nonsurgical etiologies account for a significant proportion of cases of hypoparathyroidism (~25%), and among them, genetic etiologies are key. Given the pervasive nature of PTH deficiency across multiple organ systems, a detailed review of the skeletal, renal, neuromuscular, and ocular complications is provided. The burden of illness on affected patients and their caregivers contributes to reduced quality of life and social costs for this chronic endocrinopathy. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Clinical application of parathyroid autotransplantation in endoscopic radical resection of thyroid carcinoma

Purpose

This study aimed to examine the effect of selective inferior parathyroid gland autotransplantation on central lymph node dissection(CLND) and incidence of postoperative hypoparathyroidism in patients undergoing endoscopic radical resection of thyroid carcinoma.

Methods

The data of 310 patients undergoing endoscopic radical resection of thyroid carcinoma will be retrospectively analyzed. The patients will be divided into the experimental group and the control group according to whether they combined with parathyroid autotransplantation. Statistics of the incidence rate of postoperative hypoparathyroidism, the concentration of PTH and Calcium in the systemic circulation at different time points in the two groups, the concentration of PTH in the cubital fossa vein in the transplantation region in the experimental group, and the number of central lymph nodes and positive lymph nodes dissection will be carried out.

Results

The incidence rate of temporary and permanent hypoparathyroidism in the experimental group was 33.75% and 0.625%, respectively, and in the control group was 22% and 5%, respectively; its difference was statistically significant (X^{2 =} 10.255, P=0.006). Parathyroid autotransplantation increased incidence of transient hypoparathyroidism (OR, 1.806; Cl, 1.088-2.998; P=0.022), and lower incidence of permanent hypoparathyroidism (OR, 0.112; Cl, 0.014-0.904; P=0.040). The diameters of thyroid cancer nodules was not associated with the occurrence of transient hypoparathyroidism (OR, 0.769; Cl, 0.467-1.265; P=0.301) or permanent hypoparathyroidism (OR, 1.434; Cl, 0.316-6.515; P=0.641). Comparison of systemic circulation PTH, between the two groups showed that the PTH of patients in the experimental group was higher than that in the control group from 1 week to 12 months after the operation, and the difference was statistically significant (P<0.05). In the experimental group, from 1 week to 12 months after surgery, PTH concentrations was significantly higher in the cubital fossa of the transplantation side than in the contralateral side, and the differences were statistically significant (P<0.05). The mean number of central lymph node dissected per patient was significantly higher in the experimental group (7.94 ± 3.03 vs. 6.99 ± 2.86; P <0.05); The mean number of positive nodes per patient was significantly higher in the experimental group (3.16 ± 1.86 vs. 2.53 ± 1.59; P <0.05).

Conclusions

In endoscopic radical resection of thyroid carcinoma, parathyroid autotransplantation is more beneficial to postoperative parathyroid glands function recovery, effectively preventing postoperative permanent hypoparathyroidism and realizing more thorough CLND.

Parathyroid hormone of ≥1.6 pmol/L at 6 months is associated with recovery in 'long-term' post-surgical hypoparathyroidism

Objective

Post-surgical hypoparathyroidism (PoSH) usually settles within few months after thyroid surgery, but several patients require long-term supplementation with calcium/activated vitamin D. When PoSH persists beyond 6 months, it is considered 'chronic' or 'permanent', however, late recovery has been reported. The aim of this study was to determine the frequency of late recovery and explore factors predicting late recovery of parathyroid function.

Methods

Adult patients undergoing total/completion thyroidectomy between 2009 and 2018 were included in this retrospective cohort observational study. The records of patients with evidence of PoSH were reviewed to identify those with persisting PoSH at 6 months. Demographic, biochemical, surgical, pathological, and clinical follow-up data were collected and analysed.

Results

Out of 911 patients undergoing thyroidectomy, 270 were identified with PoSH. Of these, 192 were started on supplements and 138 (71.9%) recovered within 6 months. Of the remaining 54 patients, 35 had ongoing PoSH with median (range) follow-up of 3.4 (0.5-11.1) years. Nineteen patients were weaned off supplements and achieved remission at median (range) follow-up of 1.3 (0.6-4.8) years. All of those who recovered had a PTH of ≥1.6 pmol/L at 6 months. There was no difference in age, gender, diagnosis, type, and extent of surgery between those who did and did not show late recovery.

Conclusions

Recovery from PoSH is common beyond 6 months, raising the question whether a 6-month threshold to define 'long-term' PoSH is appropriate. The chances of recovery are high (~50%) in patients with PTH level ≥1.6 pmol/L at 6 months, where attempts at weaning may be focussed.

Persistent post-thyroidectomy hypoparathyroidism: A multicenter retrospective cohort study

BACKGROUND AND OBJECTIVE

The reported incidence of persistent hypoparathyroidism varies widely, and consensus on a definition is lacking. The objective was to evaluate the real-life incidence of persistent hypoparathyroidism by investigating a new pragmatic definition.

METHODS

This retrospective multicenter cohort study evaluated the effect of different definitions for persistent hypoparathyroidism on the incidence of hypoparathyroidism. In addition, risk factors for hypoparathyroidism were analyzed.

RESULTS

In total, 749 patients were included. Using the new pragmatic definition, we report an incidence of 7.9% of persistent hypoparathyroidism. When applying other commonly used definitions, incidence varied between 11.8% and 22.1%. Risk factors were parathyroid autotransplantation, presence of another surgical complication, and low postoperative serum calcium.

CONCLUSIONS

Our data show that the incidence of persistent hypoparathyroidism in the literature may vary through the use of different definitions. This study indicates that a new pragmatic definition of persistent hypoparathyroidism has the potential to enable unbiased comparison between studies.

Late Recovery of Parathyroid Function after Total Thyroidectomy in Children and Adults: Is There a Difference?

BACKGROUND

Parathyroid failure after total thyroidectomy is the commonest adverse event amongst both children and adults. The phenomenon of late recovery of parathyroid function, especially in young patients with persistent hypoparathyroidism, is not well understood. This study investigated differences in rates of parathyroid recovery in children and adults and factors influencing this.

METHODS

A joint dual-centre database of patients who underwent a total thyroidectomy between 1998 and 2018 was searched for patients with persistent hypoparathyroidism, defined as dependence on oral calcium and vitamin D supplementation at 6 months. Demographic, surgical, pathological, and biochemical data were collected and analysed. <F00_Regular>Parathyroid Glands Remaining</F00_Regular> in Situ (PGRIS) score was calculated.

RESULTS

Out of 960 patients who had total thyroidectomy, 94 (9.8%) had persistent hypoparathyroidism at 6 months, 23 (24.5%) children with a median [range] age 10 [0-17], and 71 (75.5%) adults aged 55 [25-82] years, respectively. Both groups were comparable regarding sex, indication, extent of surgery, and PGRIS score. After a median follow-up of 20 months, the parathyroid recovery rate was identical for children and adults (11 [47.8%] vs. 34 [47.9%]; p = 0.92). Sex, extent, and indication for surgery had no effect on recovery (all p > 0.05). PGRIS score = 4 (HR = 0.48) and serum calcium >2.25 mmol/L (HR = 0.24) at 1 month were associated with a decreased risk of persistent hypoparathyroidism on multivariate analysis (p < 0.05).

CONCLUSION

Almost half of patients recovered from persistent hypoparathyroidism after 6 months; therefore, the term persistent instead of permanent hypoparathyroidism should be used. Recovery rates of parathyroid function in children and adults were similar. Regardless of age, predictive factors for recovery were PGRIS score = 4 and a serum calcium >2.25 mmol/L at 1 month.

Recovery of parathyroid function in patients with thyroid cancer treated by total thyroidectomy: An analysis of 685 patients with hypoparathyroidism at discharge of surgery

OBJECTIVE

We aimed to study the predictive factors for recovery of parathyroid function in hypoparathyroid patients after total thyroidectomy for thyroid cancer.

METHODS

We designed a retrospective, multicentre and nation-wide analysis of patients with total thyroidectomy who were seen in twenty endocrinology departments from January to March 2018. We selected patients with histologically proven thyroid cancer and retrieved information related to surgical procedure and thyroid cancer features. Survival analysis and Cox regression analysis were used to study the relationship between these variables and the recovery of parathyroid function.

RESULTS

From 685 patients with hypoparathyroidism at discharge of surgery, 495 (72.3%) recovered parathyroid function over time. Kaplan-Meier analysis showed that this recovery was significantly related to the presence of specialized surgical team (P<0.001), identification of parathyroid glands at surgery (P<0.001), papillary histopathology (P=0.040), and higher levels of postoperative calcium (Ca) (P<0.001) and parathyroid hormone (PTH) (P<0.001). Subjects with gross extrathyroidal extension (P=0.040), lymph node metastases (P=0.004), and surgical re-intervention after initial surgery (P=0.024) exhibited a significant risk of persistence of hypoparathyroidism. Multivariate Cox regression analysis showed that the significant and independent factors for recovery of parathyroid function were postoperative concentrations of Ca (P=0.038) and PTH (P=0.049). The presence of lymph node metastases was a negative predictor of recuperation of parathyroid function (P=0.042) in this analysis.

CONCLUSION

In patients with thyroid cancer, recovery of parathyroid function after total thyroidectomy was directly related to postoperative Ca and PTH concentrations, and inversely related to lymph node metastases.

Late Recovery of Parathyroid Function After Total Thyroidectomy: A Case-Control Study

The clinical characteristics of patients with postoperative hypoparathyroidism who recover parathyroid function more than 12 months after surgery have not been studied. We aimed to evaluate whether the intensity of replacement therapy with calcium and calcitriol is related to the late recovery of parathyroid function. We compared the demographic, surgical, pathological, and analytical features of two groups of patients: cases, i. e., late recovery patients (those who recover parathyroid function>1 year after thyroidectomy, n=40), and controls, i. e., patients with permanent hypoparathyroidism (n=260). Replacement therapy with calcium and calcitriol was evaluated at discharge of surgery, 3-6 months, 12 months, and last visit. No significant differences were found in clinical, surgical, pathological, or analytical characteristics between cases and controls. The proportion of cases who required treatment with calcium plus calcitriol at 12 months was significantly lower than that found in controls (p<0.001). Furthermore, daily calcium and calcitriol doses in controls were significantly higher than those in cases at 3-6 months (p=0.014 and p=0.004, respectively) and at 12 months (p<0.001 and p=0.043, respectively). In several models of logistic regression analysis therapy with calcium and calcitriol at 12 months was negatively related to late recovery of parathyroid function. Although delayed recuperation of parathyroid function after total thyroidectomy is uncommon (13%), follow-up beyond 12 months is necessary in patients with postoperative hypoparathyroidism, especially in those whose needs of treatment with Ca and calcitriol are reducing over time.

Role of the 2018 American Thyroid Association statement on postoperative hypoparathyroidism: a 5-year retrospective study

Background

Definitions of postoperative hypoparathyroidism (hypoPT) have never reached consent until the American Thyroid Association (ATA) statement was released, with new characteristics and challenges.

Methods

Patients with papillary thyroid carcinoma who underwent primary total thyroidectomy between January 2013 and June 2018 were retrospectively enrolled. Symptoms of hypocalcemia and their frequency were stringently followed. Patients were divided into groups according to the ATA statement. Incidence of postoperative hypoPT and serum parathyroid hormone levels accompanied by calcium levels, from 1-day to at least 24-month follow-up.

Results

A total of 1749 patients were included: 458 (26.2%) had transient and 63 (3.6%) had permanent hypoPT. Transient hypoPT was found in 363 (20.7%) patients with biochemical hypoPT, 72 (4.1%) with clinical hypoPT, and 23 (1.3%) with relative hypoPT; permanent hypoPT was detected in 8 (0.5%) patients with biochemical hypoPT, 55 (3.1%) with clinical hypoPT, and none with relative hypoPT. Female sex, age ≥ 55 years, unintentional parathyroid gland resection, and autotransplantation of ≥ 2 parathyroid glands were independent risk factors for transient biochemical hypoPT. Age ≥ 55 years, bilateral central neck dissection, and isthmus tumor location were independent risk factors for transient clinical hypoPT. A postoperative 1-day percentage of parathyroid hormone (PTH) reduction of > 51.1% was an independent risk factor for relative hypoPT (odds ratio, 4.892; 95% confidence interval, 1.653–14.480; P = 0.004). No independent risk factor for permanent hypoPT was found.

Conclusion

ATA diagnostic criteria for postoperative hypoPT are of great value in differentiating patients by hypocalcemia symptoms and choosing corresponding clinical assistance; however, they may underestimate the actual incidence.

What are the real rates of temporary hypoparathyroidism following thyroidectomy? It is a matter of definition: a systematic review

INTRODUCTION

Post-operative hypoparathyroidism is the most encountered complication of thyroid surgery and is classified as temporary or permanent. However, its incidence varies greatly in the literature ranging from 0.5% to 65%. This can be mainly attributed to the different definition of hypoparathyroidism used in each study and especially to the different time cutoff applied to distinguish temporary from permanent hypoparathyroidism.

METHODS

We conducted a systematic literature search in PubMed, Scopus, Cochrane and GoogleScholar databases, as well as grey literature. Ultimately, 45 articles with 23,164 patients in total were included in this review. These articles used either the cutoff of six or twelve post-operative months to distinguish temporary from permanent hypoparathyroidism.

RESULTS

The overall incidence of permanent hypoparathyroidism diagnosed at 6 months post-operatively was 4.11% and 4.08% at 12 months post-operatively. There was no statistically significant difference between the two groups (p = 0.92).

CONCLUSIONS

We suggest that adhering to the current guidelines that recommend diagnosing temporary hypoparathyroidism when recovery is made within 6 months after surgery is important when conducting future research in order to narrow the gap that exists currently in the literature, as well as when deciding to put patients on long-term calcium supplements.

Identification of Patients at High Risk for Postsurgical Hypoparathyroidism

BACKGROUND/AIM

Postsurgical hypoparathyroidism (PostHypo) is a common complication after total thyroidectomy. We studied the risk factors associated with PostHypo.

PATIENTS AND METHODS

The study included 109 women, (mean age: 50.7±10.75 years), who underwent total thyroidectomy for thyroid diseases.

RESULTS

Based on the development of biochemical hypocalcemia on the first postoperative day following total thyroidectomy, (cCa<8.4 mg/dl), 37 women developed PostHypo and 72 did not. Younger age, a lower preoperative corrected calcium and the presence of parathyroid glands in the specimens were related to the development of PostHypo. Of all patients, 51.4% had a vitamin D deficiency. A parathyroid hormone (PTH) value ≤9.4 pg/ml was 84.9% sensitive and 71.4% specific to predict PostHypo on the 1^st postoperative day. A 50% reduction of the PTH value on the 1^st postoperative day from the preoperative level could identify patients who develop PostHypo with 76% sensitivity and 75% specificity.

CONCLUSION

PTH postoperative measurement and its alteration from the preoperative level can be used to identify patients who are at increased risk to develop PostHypo.

Risks and prediction of postoperative hypoparathyroidism due to thyroid surgery

We aimed to investigate the prevalence of postoperative hypoparathyroidism (PoH), the relevant factors, and predictors of transient or permanent hypoparathyroidism. The files of 352 patients who underwent bilateral total thyroidectomy alone or with central lymph node dissection and/or lateral neck dissection between June 1, 2019, and November 30, 2019, were retrospectively evaluated. Also, calcium and parathyroid hormone levels measured preoperatively and 4–6 h after surgery, follow-up examination results, and time to resolution of transient PoH were recorded. 16.48% (n = 58) of the surgical patients developed transient PoH and 3.98% (n = 14) developed permanent PoH. Length of hospital stay increased in patients who developed PoH (p < 0.001). Transient PoH developed less in patients who underwent parathyroid autotransplantation, while permanent PoH was not detected (p = 0.001). PoH development was not significantly correlated with nodule size as measured by preoperative thyroid ultrasonography (p = 0.944). Patients who had a serum PTH level ≤ 5.95 pmol/L 4–6 h after surgery had a greater risk of developing permanent PoH (OR 134.84, 95% CI 17.25–1053.82). PoH is more common in female gender and is not significantly correlated with nodule size. Parathyroid autotransplantation can prevent the development of PoH.

Complications after medullary thyroid carcinoma surgery: multicentre study of the SQRTPA and EUROCRINE® databases

BACKGROUND

Surgery is the curative therapy for patients with medullary thyroid carcinoma (MTC). In determining the extent of surgery, the risk of complications should be considered. The aim of this study was to assess procedure-specific outcomes and risk factors for complications after surgery for MTC.

METHODS

Patients who underwent thyroid surgery for MTC were identified in two European prospective quality databases. Hypoparathyroidism was defined by treatment with calcium/active vitamin D. Recurrent laryngeal nerve (RLN) palsy was diagnosed on laryngoscopy. Complications were considered at least transient if present at last follow-up. Risk factors for at-least transient hypoparathyroidism and RLN palsy were identified by logistic regression analysis.

RESULTS

A total of 650 patients underwent surgery in 69 centres at a median age of 56 years. Hypoparathyroidism, RLN palsy and bleeding requiring reoperation occurred in 170 (26·2 per cent), 62 (13·7 per cent) and 17 (2·6 per cent) respectively. Factors associated with hypoparathyroidism were central lymph node dissection (CLND) (odds ratio (OR) 2·20, 95 per cent c.i. 1·04 to 4·67), CLND plus unilateral lateral lymph node dissection (LLND) (OR 2·78, 1·20 to 6·43), CLND plus bilateral LLND (OR 2·83, 1·13 to 7·05) and four or more parathyroid glands observed (OR 4·18, 1·46 to 12·00). RLN palsy was associated with CLND plus LLND (OR 4·04, 1·12 to 14·58) and T4 tumours (OR 12·16, 4·46 to 33·18). After compartment-oriented lymph node dissection, N0 status was achieved in 248 of 537 patients (46·2 per cent).

CONCLUSION

Complications after surgery for MTC are procedure-specific and may relate to the unavoidable consequences of radical dissection needed in some patients.

Short-term recovery in patients suffering hypoparathyroid after thyroidectomy: a case control study

BACKGROUND

Postoperative hypoparathyroidism is the main reason for outpatient follow-up and long-term oral calcium and calcitriol treatment. Our study investigated the influencing factors and powerful predictors of short-term postoperative parathyroid function recovery.

METHODS

Logistic regression was used to compare the clinicopathological characteristics; surgical details; and serum calcium (Ca), magnesium (Mg), and phosphorus (P) concentrations of patients. A receiver operating characteristic (ROC) curve was used to analyze the predictors of normal parathyroid hormone (PTH).

RESULTS

Among the 111 patients with PTH < 10 pg/mL on the first postoperative day, most patients experienced a return to normal PTH (PTH > 15 pg/mL) within 30 days postoperatively. Univariate analysis showed that Pod (postoperative day) 1 PTH, Pod3 PTH, Pod7 Ca, Pod7 Mg, and Pod7 P (P < 0.05) were associated with parathyroid function recovery to normal on the seventh postoperative day. Multivariate logistic regression analysis revealed the following independent risk factors for normal PTH levels at Pod7 after thyroidectomy: Pod3 PTH (P = 0.038), Pod1 PTH (P = 0.056), Pod7 Mg (P = 0.001), Pod7 P (P = 0.020), and the number of parathyroid glands in situ intraoperatively. The combined sensitivity of serum magnesium concentration and phosphorus concentration to predict parathyroid function recover to normal on the seventh postoperative day was 82.76%, with a sensitivity of 76.83%.

CONCLUSION

Serum magnesium, phosphorus and PTH concentrations are important influencing factors and effective predictors of short-term postoperative parathyroid function recovery to normal. Serum ion is an effective auxiliary diagnostic method for hypoparathyroidism after thyroidectomy.

The Relationship of Magnesium Level with the Recovery of Parathyroid Function in Post-thyroidectomy Hypoparathyroidism

Objectives

Hypocalcemia is the most common complication and acute parathyroid gland insufficiency is the main cause of it after thyroidectomy. In this study, we aimed to evaluate the relationship between the recovery time of parathyroid gland function and patient characteristics, preoperative and postoperative electrolyte changes, and intraoperative parathyroid findings in patients with postoperative hypoparathyroidism.

Methods

Patients who underwent total thyroidectomy (TT) with or without central neck dissection ± lateral neck dissection with a parathyroid hormone (PTH) value of <15 pg/mL within the postoperative 4th hour were included in this study. Postoperative calcium level of <8mg/dL was defined as biochemical hypocalcemia and a PTH value of <15 pg/mL was defined as hypoparathyroidism. The patients were divided into three groups according to the time of PTH recovery (>15 pg/mL); within the first 24 hours, between one day and 30 days, after 30 days, respectively.

Results

One hundred eleven patients (mean age, 49.3±14.4 years) consisted of Groups 1, 2 and 3, including 19 (16F, 3M), 67 (54F, 13M) and 25 (19F, 6M), respectively. Vitamin D deficiency rates for Groups 1, 2, 3 were 41.7%, 53.1% and 88.2%, respectively (p=0.018). Postoperative day 0 PTH values were 11.69±2.79pg/mL, 6.92±3.45 pg/mL, 4.99±2.36 pg/mL, (p<0.001). Biochemical hypocalcemia rates of Groups 1, 2, 3 on postoperative day 1 were 15.8%, 53.7%, 64%, (p=004) respectively, and calcium values were 8.68±0.67 mg/dL, 8.15±0.66 mg/dL, 7.75±1 mg/dL, (p=0.014), respectively. Magnesium values on postoperative day 1 and 7 for Groups 1, 2, 3 were 1.85±0.1 mg/dL, 1.77±0.17 mg/dL, 1.64±0.17 mg/dL, (p=0.005), and 1.86±0.16mg/dL, 1.82±0.21mg/dL, 1.59±0.15mg/dL (p=0.001), respectively. PTH values on postoperative day 1 and 7 in Groups 1, 2, 3 were 20.5±6.4 pg/mL, 7.06±4.35 pg/mL, 4.66±3.26 pg/mL (p<0.001), and 31.04±10.54pg/mL, 18.72±13.84pg/mL, 4.55±4.9pg/mL (p<0.0001), respectively. Parathyroid function improved in 106 patients, and permanent hypoparathyroidism developed in five patients (4.5%).

Conclusion

Hypoparathyroidism can recover rapidly in the first 24 hours in patients with a PTH value of around 10 pg/mL at postoperative 4th hour. As the number of preserved parathyroids increased, recovery time decreased. In patients with postoperative hypoparathyroidism, postoperative low magnesium levels may be associated with delayed recovery of parathyroid function.

Etiology and Diagnosis of Permanent Hypoparathyroidism after Total Thyroidectomy

Postoperative parathyroid failure is the commonest adverse effect of total thyroidectomy, which is a widely used surgical procedure to treat both benign and malignant thyroid disorders. The present review focuses on the scientific gap and lack of data regarding the time period elapsed between the immediate postoperative period, when hypocalcemia is usually detected by the surgeon, and permanent hypoparathyroidism often seen by an endocrinologist months or years later. Parathyroid failure after thyroidectomy results from a combination of trauma, devascularization, inadvertent resection, and/or autotransplantation, all resulting in an early drop of iPTH (intact parathyroid hormone) requiring replacement therapy with calcium and calcitriol. There is very little or no role for other factors such as vitamin D deficiency, calcitonin, or magnesium. Recovery of the parathyroid function is a dynamic process evolving over months and cannot be predicted on the basis of early serum calcium and iPTH measurements; it depends on the number of parathyroid glands remaining in situ (PGRIS)—not autotransplanted nor inadvertently excised—and on early administration of full-dose replacement therapy to avoid hypocalcemia during the first days/weeks after thyroidectomy.

Recovery of severely damaged parathyroid function after total thyroidectomy for thyroid cancer

Background

An extremely low parathyroid hormone (PTH) concentration after thyroidectomy may reflect the immediate severely damaged parathyroid function. The current study aimed to examine time-related changes of severely damaged parathyroid function on postoperative day 1 (SDPF-D1), which was here defined as serum PTH ≤1 pg/mL, and the risk factors of SDPF-D1.

Methods

This is a retrospective review of patients with thyroid cancer undergoing total thyroidectomy with or without central neck dissection (CND). The number of parathyroids preserved in situ, autotransplanted, or found in the final pathology was recorded and the corresponding parathyroid glands remaining in situ (PGRIS) score (PGRIS = 4 - parathyroids autotransplanted-parathyroids found in the final pathology) was calculated. Chronological changes of serum levels of PTH and total calcium were investigated for at least one year after surgery.

Results

One hundred and twenty-two of 344 patients included for analysis suffered from SDPF-D1. Patients with SDPF-D1 had a prolonged recovery in comparison with hypoparathyroidism patients without SDPF-D1, who fully recovered within 6 months after thyroidectomy. The PGRIS score in patients with permanent hypoparathyroidism was significantly lower than other patients with SDPF-D1who fully recovered.

Conclusions

Most patients with SDPF-D1 could fully recover within one year after total thyroidectomy. Less parathyroids removed and autotransplanted contributed to a quick recovery of SDPF-D1.

Duration of Parathyroid Function Recovery in Patients With Protracted Hypoparathyroidism After Total Thyroidectomy for Papillary Thyroid Carcinoma

PURPOSE

The aim of the present study is to investigate the time to recovery of parathyroid function in patients with protracted hypoparathyroidism at 1 month after total thyroidectomy of papillary thyroid carcinoma.

MATERIALS AND METHODS

Adult patients who underwent total thyroidectomy for papillary thyroid cancer were included. Cases of long-term hypoparathyroidism were studied for recovery of parathyroid function during the follow-up. The duration of recovery and associated variables were recorded.

RESULTS

Out of the 964 patients, 128 (13.28%) developed protracted hypoparathyroidism and of these, 23 (2.39%) developed permanent hypoparathyroidism and 105 (10.89%) recovered: 86 (8.92%) before 6 months, 11 (1.14%) within 6 and 12 months and 8 (0.83%) after 1 year follow-up. Variables significantly associated with the time to parathyroid function recovery were number of autotransplanted parathyroid glands (HR, 1.399; 95% CI, 1.060 - 1.846; P = 0.018), serum calcium concentration >2.07 mmol/L (Hazard ratio [HR], 1.628; 95% confidence interval [CI], 1.009 - 2.628; P = 0.046) and PTH level > 1.2 pmol/L (HR, 1.702; 95% CI, 1.083 - 2.628; P = 0.021) at 1 month postoperatively.

CONCLUSION

Permanent hypoparathyroidism should not be diagnosed easily by time, since up to one-fifth of the patients will experience recovery after a period of 6 months and a few patients even beyond one year. The number of autotransplanted parathyroid glands is positively associated with the time to parathyroid function recovery.

Permanent postoperative hypoparathyroidism: an analysis of prevalence and predictive factors for adequacy of control in a cohort of 260 patients

Background

Recent guidelines for the treatment of hypoparathyroidism emphasize the need for long-term disease control, avoiding symptoms and hypocalcaemia. Our aim has been to analyze the prevalence of poor disease control in a national cohort of patients with hypoparathyroidism, as well as to evaluate predictive variables of inadequate disease control.

Methods

From a nation-wide observational study including a cohort of 1792 patients undergoing total thyroidectomy, we selected 260 subjects [207 women and 53 men, aged (mean ± SD) 47.2±14.8 years] diagnosed with permanent hypoparathyroidism. In every patient demographic data and details on surgical procedure, histopathology, calcium (Ca) metabolism, and therapy with Ca and calcitriol were retrospectively collected. A patient was considered not adequately controlled (NAC) if presented symptoms of hypocalcemia or biochemical data showing low serum Ca levels or high urinary Ca excretion.

Results

Two hundred and twenty-one (85.0%) patients were adequately controlled (AC) and 39 (15.0%) were NAC. Comparison between AC and NAC patients did not show any significant difference in demographic, surgical, and pathological features. Rate of hospitalization during follow-up was significantly higher among NAC patients in comparison with AC patients (35.9% vs. 10.9%, P<0.001). Dose of oral Ca and calcitriol were also significantly higher in NAC subjects. In a subgroup of 129 patients with serum parathyroid hormone (PTH) levels available, we found that NAC patients exhibited significantly lower postoperative PTH concentrations than AC patients [median (interquartile range) 3 (1.9-7.8) vs. 6.9 (3.0-11) pg/mL; P=0.009].

Conclusions

In a nation-wide cohort of 260 subjects with definitive hypoparathyroidism, 15% of them had poor disease control. These patients required higher doses of oral Ca and calcitriol, had higher rate of hospitalization during follow-up and showed lower PTH concentrations in the postoperative period.

Prevalence of basal ganglia and carotid artery calcifications in patients with permanent hypoparathyroidism after total thyroidectomy

OBJECTIVE

Permanent hypoparathyroidism is an uncommon disease resulting most frequently from neck surgery. It has been associated with visceral calcifications but few studies have specifically this in patients with post-surgical hypoparathyroidism. The aim of the present study was to assess the prevalence of basal ganglia and carotid artery calcifications in patients with long-term post-thyroidectomy hypoparathyroidism compared with a control population.

DESIGN

Case-control study.

METHODS

A cross-sectional review comparing 29 consecutive patients with permanent postoperative hypoparathyroidism followed-up in a tertiary reference unit for Endocrine Surgery with a contemporary control group of 501 patients who had an emergency brain CT scan. Clinical variables and prevalence of basal ganglia and carotid artery calcifications were recorded.

RESULTS

From a cohort of 46 patients diagnosed with permanent hypoparathyroidism, 29 were included in the study. The mean duration of disease was 9.2 ± 7 years. Age, diabetes, hypertension, smoking and dyslipidemia were similarly distributed in case and control groups. The prevalence of carotid artery and basal ganglia calcifications was 4 and 20 times more frequent in patients with permanent hypoparathyroidism, respectively. After propensity score matching of the 28 the female patients, 68 controls were matched for age and presence of cardiovascular factors. Cases showed a four-fold prevalence of basal ganglia calcifications, whereas that of carotid calcifications was similar between cases and controls.

CONCLUSION

A high prevalence of basal ganglia calcifications was observed in patients with post-surgical permanent hypoparathyroidism. It remains unclear whether carotid artery calcification may also be increased.

A registry for patients with chronic hypoparathyroidism in Russian adults

Hypoparathyroidism and pseudohypoparathyroidism are rare endocrine disorders, characterized by low serum calcium due to inappropriate parathyroid hormone (PTH) levels or resistance to its action. There is little epidemiological information regarding chronic hypoparathyroidism in Russia. This study aims to build a registry database of Russian patients with chronic hypoparathyroidism who were referred for hospital treatment in order to conduct initial analysis of clinical presentations and hospital management. The Italian registry model was taken to be able to integrate our data in the future. Two hundred patients with hypoparathyroidism (n = 194) and pseudohypoparathyroidism (n = 6) were enrolled over 2 years (2017-2019). The most frequent cause of hypoparathyroidism was neck surgery (82.5%, mostly females), followed by idiopathic hypoparathyroidism (10%), syndromic forms of genetic hypoparathyroidism (4.5%) and forms of defective PTH action (3%). Calcium supplements and alfacalcidol were prescribed in most cases. However, a minority of patients (n = 6) needed to receive teriparatide as the only way to maintain calcium levels and to prevent symptoms of hypocalcemia. Consequently, substitution treatment with parathyroid hormone should be available in certain cases of hypoparathyroidism. This database will be useful to estimate the potential requirement for recombinant PTH in Russia and standards for clinical and therapeutic approaches.

Children are at a high risk of hypocalcaemia and hypoparathyroidism after total thyroidectomy

PURPOSE

Disruption of calcium homeostasis is the most common complication after total thyroidectomy in adults. We explored the incidence and risk factors of hypocalcaemia and hypoparathyroidism after total thyroidectomy in children (≤18 years of age).

METHODS

One hundred six children underwent total thyroidectomy. Patient, operative and outcome data were collected and analyzed.

RESULTS

The indication for surgery was Graves' disease in 52 children (49.1%), Multiple Endocrine Neoplasia type-2 in 36 (33.9%), multinodular goiter in 3 (2.8%) and follicular/papillary thyroid carcinoma in 15 (14.2%). Neck dissection was performed in 23 children (18.9%). In 14 children (13.2%), autotransplantation was performed; in 31 (29.2%), ≥1 glands were found in the specimen. Hypocalcaemia within 24 h of thyroidectomy was observed in 63 children (59.4%) and 52 (49.3%) were discharged on supplements. Hypoparathyroidism at 6 months persisted in 23 children (21.7%). The ratios of all forms of calcium-related-morbidity were larger among children with less than four parathyroid glands remaining in situ: hypocalcaemia within 24 h of thyroidectomy (54.0% versus 47.5%; p = 0.01), hypoparathyroidism on discharge (64.4% versus 37.7%; p = 0.004) and long-term hypoparathyroidism (31.1% versus 14.8%; p = 0.04).

CONCLUSION

The incidence of postoperative hypocalcaemia and hypoparathyroidism among children undergoing total thyroidectomy is considerable. The inability to preserve the parathyroid glands in situ during surgery seems an important factor. For optimal outcomes, the parathyroid glands should be preserved in situ.

TYPE OF STUDY

Prognosis Study.

LEVEL OF EVIDENCE

Level IV.

Ocular Findings Associated with Hypoparathyroidism

Purpose: To determine the corneal and retinal changes associated with serum calcium, phosphorus and parathyroid hormone (PTH) levels in patients with hypoparathyroidism.Methods: Patients who were under follow-up for hypoparathyroidism in the endocrinology department were included in the study. All participants underwent a complete ophthalmological examination. Moreover, central corneal thickness (CCT), anterior chamber depth (ACD), retinal nerve fiber layer (RNFL) thickness, ganglion cell layer (GCL) thickness were recorded. Serum biochemical parameters were recorded.Results: In a total of 75 patients (35 in the hypoparathyroidism group and 40 in the healthy control group) were included in this study. Central corneal thickness (519.95 ± 33.21 vs. 539.10 ± 32.96, p: 0.001) and RNFL (105.10 ± 11.89 vs. 113.56 ± 9.54, p: 0.005) were significantly thinner and ACD was significantly deeper in the hypoparathyroidism group.Conclusion: We determined thinner CCT and RNFL values in patients with hypoparathyroidism related to serum calcium levels together with a significant deepness in ACD.

[Hypoparathyroidism - un underestimated problem?]

BACKGROUND

Hypoparathyroidism is a rare and disabilitating disorder characterized by hypocalcemia and low parathyroid hormone levels. Most of the cases occur as a result of the removal of parathyroid glands or damage to the glands during neck surgery. More rare causes include nonsurgical causes such as autoimmune or genetic diseases.

METHOD

In this review, a panel of experts presents the current state of diagnosis and therapy of hypoparathyroidism and explains practical aspects of caring for the affected patients.

RESULTS

Common signs and symptoms are abnormal sensations and increased excitability in the lower limbs, paresthesia of perioral areas and nocturnal leg cramps. Renal complications frequently occur, but also basal ganglia calcification. Treatment consists of administration of vitamin D analogs in combination with 0.5-1.0 g calcium daily. An adjunctive treatment with the in April 2017 approved recombinant human parathyroid hormone (1-84) is an option for patients whose hypoparathyroidism is difficult to control by conventional treatment alone. Initially and after dose changes follow-up controls should be performed at least every 2 weeks, in well-controlled patients or in the case of chronic progression every 3-6 months.

Influence of gender and women's age on the prevalence of parathyroid failure after total thyroidectomy for multinodular goiter

Background

Female gender, particularly of a young age, has been reported as a risk factor for hypocalcemia after total thyroidectomy. There are no studies, however, addressing specifically the influence of women's age and menstrual status on postoperative parathyroid function.

Methods

Cohort study of consecutive patients undergoing total thyroidectomy for benign goiter between 2000-2017, excluding those with associated hyperparathyroidism, reoperation or conservative procedures. Prevalence of postoperative hypocalcemia (s-Ca <8 mg/dL at 24 hours), protracted (1-month) and permanent hypoparathyroidism (>1 year) were the main variables studied. Complete >1-year follow-up was achieved for all patients developing post-thyroidectomy hypocalcemia. Demographic, disease-related, number of parathyroid glands remaining in situ (PGRIS), biochemical and surgical variables were recorded. The impact of menstrual status on parathyroid function was analyzed by comparing two groups of women using a cut-off age of 45 years.

Results

A total of 811 patients were included: 14 percent were males and 86 percent females with a mean age of 53.2 years. The prevalence of postoperative hypocalcemia was ten points higher in women than in men (23.7% vs. 36.4%; P=0.008). Permanent hypoparathyroidism was more common in women than in men (5% vs. 0.9%; P=0.048). Compared to females ≥45 years, young women presented higher rates of all three parathyroid failure syndromes despite similar PGRIS scores. Age <45 years and low PGRIS scores were the only independent variables predicting postoperative hypocalcemia in females.

Conclusions

Premenopausal patients presented a higher prevalence of parathyroid failure and permanent hypoparathyroidism with similar PGRIS scores suggesting the presence of a sex-hormone factor influencing post-thyroidectomy parathyroid function.

Postoperative Hypoparathyroidism After Total Thyroidectomy in Children

BACKGROUND

Postoperative hypocalcemia because of hypoparathyroidism is the most common complication of total thyroidectomy in children. We hypothesized that most children with postoperative hypocalcemia would be eucalcemic by 12 mo and sought to define risk factors for permanent hypoparathyroidism.

METHODS

We retrospectively reviewed children who underwent total thyroidectomy at a single children's hospital from 2012 to 2019. Patients with prior neck surgery were excluded. Indication for operation, final pathologic diagnosis, and postoperative serum calcium up to 12 mo were recorded. Permanent hypoparathyroidism was defined as supplemental calcium requirement beyond 1 y postoperatively.

RESULTS

Sixty-eight patients underwent total thyroidectomy. Graves' disease was the most common benign indication for surgery (38 patients). Twenty-six patients (38%) had cancer on final pathology. Central lymph node dissection (CLND) was performed in 12 cancer patients. Twenty-eight patients (41%) had postoperative hypocalcemia. Eight patients (12%) had hypocalcemia at 6 mo. Risk factors for hypoparathyroidism at 6 mo were a cancer diagnosis (odds ratio [OR] 6.7; P = 0.02), CLND (OR 12.6; P < 0.01), and parathyroid tissue in the surgical specimen on pathologic analysis (OR 19.5; P < 0.01). Only two patients (3%) developed permanent hypoparathyroidism, both of whom had thyroidectomy for cancer and underwent CLND.

CONCLUSIONS

Children with thyroid cancer are at high risk for postoperative hypocalcemia after total thyroidectomy. The risk is further increased by CLND, which should be performed selectively. A majority of patients with hypoparathyroidism at 6 mo postoperatively regain normal parathyroid function by 1 y. Permanent hypoparathyroidism in children after total thyroidectomy at a pediatric endocrine surgery center is rare.

Risks of Hypoparathyroidism After Total Thyroidectomy in Children: A 21-Year Experience in a High-Volume Cancer Center

BACKGROUND

Hypoparathyroidism occurs relatively frequently after thyroid surgery in children. However, few studies have reported risk factors. We aimed to identify risk factors for hypoparathyroidism that occurred after total thyroidectomy for proven or suspected malignancy in children.

METHODS

Children (aged ≤ 18 years) who underwent total thyroidectomy for neoplasm or RET germline mutation at our institution between 1997 and 2018 were included. We retrospectively reviewed demographics, surgical indications, perioperative and follow-up laboratory results, pathologic results, and duration of calcium/calcitriol supplementation. Risk factors for hypoparathyroidism were identified by multivariate analysis.

RESULTS

Of 184 consecutive patients, 111 had undergone surgery for neoplasm; these diseases were primarily malignancies (106, 95.5%), predominantly papillary carcinoma (103, 92.8%). The remaining 73 patients had undergone early thyroidectomy for RET germline mutation. Among all patients, 67 (36.4%) had hypoparathyroidism: 61 transient and 6 permanent. In a multivariate analysis, central neck dissection (odds ratio 4.3, 95% confidence interval 2.0-9.1) and gross extrathyroidal extension (odds ratio 4.9, 95% confidence interval 2.0-12.1) predicted overall hypoparathyroidism; however, no significant factors were associated with permanent hypoparathyroidism. Most patients with permanent hypoparathyroidism (5 of 6) had undergone therapeutic central neck dissection. When central neck dissection was performed, younger children had a higher risk of overall hypoparathyroidism.

CONCLUSIONS

In pediatric total thyroidectomies, central neck dissection and gross extrathyroidal extension were major predictors for overall hypoparathyroidism. Surgeons performing thyroidectomy in such patients should be aware of the relatively high risk, preserve parathyroid tissue to the extent possible, and be conscientious regarding postoperative calcium monitoring and replacement.

Prevalence and risk factors for hypoparathyroidism following total thyroidectomy in Spain: a multicentric and nation-wide retrospective analysis

PURPOSE

The prevalence of postoperative hypoparathyroidism has been studied in registries and in surgical series with highly variable and imprecise results. However, the frequency of this hormonal deficiency in the clinical practice of endocrinologists is not known with accuracy. We aimed to assess the prevalence and risk factors of hypoparathyroidism in patients undergoing total thyroidectomy in Spain.

METHODS

We designed a retrospective, multicentre and nation-wide protocol including all patients with total thyroidectomy who were seen in the endocrinology clinic of the participant centers from January to March 2018. Prevalence of hypoparathyroidism was evaluated at discharge of surgery, 3-6 months after surgery, 12 months after surgery and at last visit. Twenty hospitals participated in the study.

RESULTS

Of 1792 patients undergoing total thyroidectomy, 866 (48.3%) developed postoperative hypoparathyroidism at discharge of surgery. Most of them recover parathyroid function over time. Prevalence of hypoparathyroidism at 3-6 months, 12 months and at last visit was 22.9%, 16.7% and 14.5%, respectively. The risk of developing definitive hypoparathyroidism was related to the presence of parathyroid tissue at histology, lymph node dissection, and two-stage thyroidectomy. Patients with thyroid cancer, with higher postoperative calcium levels and treated by expert surgical teams exhibited lower risk of developing permanent hypoparathyroidism.

CONCLUSIONS

Although most patients with postsurgical hypoparathyroidism recover parathyroid function, the prevalence of permanent disease in clinical practice is non negligible (14.5%). Postoperative calcium, extent and timing of surgery, the presence of cancer, expert surgical team, and parathyroid tissue at histology are predictors of permanent hypoparathyroidism.

MANAGEMENT OF ENDOCRINE DISEASE: Unmet therapeutic, educational and scientific needs in parathyroid disorders

PARAT, a new European Society of Endocrinology program, aims to identify unmet scientific and educational needs of parathyroid disorders, such as primary hyperparathyroidism (PHPT), including parathyroid cancer (PC), and hypoparathyroidism (HypoPT). The discussions and consensus statements from the first PARAT workshop (September 2018) are reviewed. PHPT has a high prevalence in Western communities, PHPT has a high prevalence in Western communities, yet evidence is sparse concerning the natural history and whether morbidity and long-term outcomes are related to hypercalcemia or plasma PTH concentrations, or both. Cardiovascular mortality and prevalence of low energy fractures are increased, whereas Quality of Life is decreased, although their reversibility by treatment of PHPT has not been convincingly demonstrated. PC is a rare cause of PHPT, with an increasing incidence, and international collaborative studies are required to advance knowledge of the genetic mechanisms, biomarkers for disease activity, and optimal treatments. For example, ~20% of PCs demonstrate high mutational burden, and identifying targetable DNA variations, gene amplifications and gene fusions may facilitate personalized care, such as different forms of immunotherapy or targeted therapy. HypoPT, a designated orphan disease, is associated with a high risk of symptoms and complications. Most cases are secondary to neck surgery. However, there is a need to better understand the relation between disease biomarkers and intellectual function, and to establish the role of PTH in target tissues, as these may facilitate the appropriate use of PTH substitution therapy. Management of parathyroid disorders is challenging, and PARAT has highlighted the need for international transdisciplinary scientific and educational studies in advancing in this field.

Correlation between iPTH Levels on the First Postoperative Day After Total Thyroidectomy and Permanent Hypoparathyroidism: Our Experience

Permanent hypoparathyroidism is the most common long-term complication after thyroidectomy. We evaluated whether iPTH concentrations on the first postoperative day may be a good predictor of this complication.

Patients undergoing thyroidectomy in our Unit between January 2017 and February 2018 who developed postsurgical hypoparathyroidism were analysed. According to iPTH values on the first postoperative day and on the basis of the detection threshold of the iPTH test used, patients were divided into 2 groups: Group A (iPTH < 6.3 pg/mL, undetectable), Group B (iPTH ≥ 6.3 pg/mL).

Seventy-five patients were included in this study: 64 in Group A and 11 in Group B. Permanent hypoparathyroidism occurred in 14 (21.88%) patients in Group A, while none developed this complication in Group B. When iPTH was < 6.3 pg/mL, the sensitivity for the prediction of permanent hypoparathyroidism was 100%, the specificity was 18.03%, the positive predictive value was 21.88% and the negative predictive value was 100%.

No patient with iPTH ≥ 6.3 pg/mL on the first postoperative day developed permanent hypoparathyroidism. On the other hand, iPTH concentrations < 6.3 pg/mL have not proved to be a strong predictor of this condition. However, this cut-off value can be useful to identify patients at risk of developing this complication.

Hypocalcemic disorders

Calcium is vital for life, and extracellular calcium concentrations must constantly be maintained within a precise concentration range. Low serum calcium (hypocalcemia) occurs in conjunction with multiple disorders and can be life-threatening if severe. Symptoms of acute hypocalcemia include neuromuscular irritability, tetany, and seizures, which are rapidly resolved with intravenous administration of calcium gluconate. However, disorders that lead to chronic hypocalcemia often have more subtle manifestations. Hypoparathyroidism, characterized by impaired secretion of parathyroid hormone (PTH), a key regulatory hormone for maintaining calcium homeostasis, is a classic cause of chronic hypocalcemia. Disorders that disrupt the metabolism of vitamin D can also lead to chronic hypocalcemia, as vitamin D is responsible for increasing the gut absorption of dietary calcium. Treatment and management options for chronic hypocalcemia vary depending on the underlying disorder. For example, in patients with hypoparathyroidism, calcium and vitamin D supplementation must be carefully titrated to avoid symptoms of hypocalcemia while keeping serum calcium in the low-normal range to minimize hypercalciuria, which can lead to renal dysfunction. Management of chronic hypocalcemia requires knowledge of the factors that influence the complex regulatory axes of calcium homeostasis in a given disorder. This chapter discusses common and rare disorders of hypocalcemia, symptoms and workup, and management options including replacement of PTH in hypoparathyroidism.

Parathyroid autotransplantation in thyroid surgery

BACKGROUND

Careful parathyroid gland dissection and in situ preservation was the time-honored approach to prevent parathyroid failure after total thyroidectomy. The relative success of parathyroid autotransplantation of hyperplastic parathyroid tissue in patients with renal or hereditary hyperparathyroidism did popularize the use of normal parathyroid tissue autografts during thyroidectomy to prevent permanent hypoparathyroidism. Proof of autograft function in this setting, however, is controversial.

PURPOSE

This narrative review aims at reviewing critically the current status of parathyroid autotransplantation during total thyroidectomy. It is also meant to analyze from the historical, methodological, and clinical points of view the claimed benefit of normal parathyroid gland autotransplantation. A focus is placed on the prevention of permanent hypoparathyroidism by parathyroid autotransplantation.

CONCLUSIONS

Liberal parathyroid autotransplantation was proposed in the mid 1970s but evidence of function is scarce. Proofs are accumulating that parathyroid autografts not only increase the rate of postoperative hypocalcemia, but may be also contribute to permanent hypoparathyroidism.