Which criterion of intraoperative iPTH assay is the most accurate in prediction of true serum calcium levels after thyroid surgery?

Early parathyroid hormone (PTH) level as a predictor of post-surgical hypoparathyroidism

INTRODUCTION

Post-operative hypocalcemia and postoperative persistent hypoparathyroidism remain the most common complications after thyroidectomy. Many approaches have been developed to prevent them, but actually, a common protocol is not yet individuated.

MATERIALS AND METHODS

We retrospectively analyzed the results of a prospectively collected database. We dosed PTH preoperatively and 4 h after surgery (PTH_4); calcium was evaluated preoperatively, on the first (I_POD) and on the second postoperative day (II_POD). Hypocalcemia was defined when calcium <8 mg/dl. PTH_4 and I_POD calcium serum levels are identified to predict postoperative hypocalcemia.

RESULTS

Three hundred and forty-eight patients were enrolled, 37 patients resulted as hypocalcemic on I_POD and 41 on the II_POD. PTH_4 is related to I_POD (p < 0.001, r = 0.45) and II_POD (p < 0.001, r = 0.44) calcemia. PTH_4-cut-off predicting I_POD hypocalcemia was 10.50 pg/ml (sensitivity: 78.7%, specificity: 72.7%). A PTH_4 value of 11.5 pg/ml is able to predict hypocalcemia during II_POD (sensitivity: 76.5%, specificity: 69.2%). We set up a combined test to predict II_POD hypocalcemia, using PTH_4 and I_POD calcium (sensitivity: 77.8%, specificity: 89.9%).

CONCLUSION

This research shows the association between PTH_4 and postoperative hypocalcemia. The PTH_4 cut-off to predict I_POD-hypocalcemia was 10.5 pg/ml. We analyzed the calcemia trend during the postoperative period and we realized a combined test using PTH_4 and I_POD-calcemia. This test improves the accuracy of the previous test. Further studies, in particular multicentric, with a larger sample are necessary to validate the combined model.

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.

Serum PTH at 4 h after total thyroidectomy as a predictor of hypocalcemia: a prospective time frame analysis in search of evidence

INTRODUCTION

There has not been a universal agreement about the timings and the threshold level of PTH that can accurately predict the risk of hypocalcemia. Our study aimed to investigate the changes in the serum PTH levels at various time intervals and correlate it with the development of subsequent hypocalcemia.

MATERIALS AND METHODS

All patients had a pre-operative serum PTH done and were again assessed intra-operatively, at 4 h, 24 h, 72 h, and 1 month after the thyroid surgery. Absolute serum PTH value at various time points, absolute change in serum PTH values compared to pre-operative level, and relative change (percentage change) in serum PTH values compared with pre-operative levels were used to predict post-operative Hypocalcemia.

RESULTS

49 patients were included in the study. The sensitivity and negative predictive value was 100% for serum PTH at 4 h. There was a statistically significant difference between the groups that required calcium supplementation versus the group that did not require it. The maximum relative reduction in serum PTH value with respect to the pre-operative level occurred at 4 h in the calcium supplement required group which was 82.5%. Use of combination of 4 h serum PTH and relative change at 4 h yielded the best results.

CONCLUSION

A combination of absolute serum PTH level at 4 h and the relative decline in serum PTH at 4 h has the highest diagnostic accuracy. The use of this combined parameter helps to reliably predict patients who would require supplementation.

A Parathyroid Hormone-guided Calcium and Calcitriol Supplementation Protocol Reduces Hypocalcemia-related Readmissions Following Total Thyroidectomy

OBJECTIVE

To determine the effect of a 4 hour postoperative serum parathyroid hormone (PTH) guided calcium and calcitriol supplementation protocol on the incidence of hypocalcemia and hospital readmissions in patients undergoing total thyroidectomy.

METHODS

This was a single institution, retrospective chart review of patients who underwent total thyroidectomy, 148 had been operated on prior to the protocol implementation and 389 after. Hypocalcemia risk was stratified as low (PTH >30 pg/ml), medium (15-30 pg/ml), and high (<15 pg/ml), using serum PTH values obtained 4 hours postoperatively. Hypocalcemia was defined as a total serum calcium level <8 mg/dl. Baseline demographic and operative characteristics, and postoperative outcome were recorded for both groups. Fisher's exact test or Wilcoxon rank sum test were used to compare the characteristics of the two groups. A multivariable logistic regression model was applied to account for potentially confounding variables.

RESULTS

Postoperative hypocalcemia occurred significantly less frequently in the protocol group compared to the preprotocol group (10.3% vs. 20.9%, P=.002). The reduction in hypocalcemia in the protocol group was observed both in patients with (16.3% vs. 25.6%) and without (8.4% vs. 19.3%) cervical lymph node dissection. There was a significantly lower incidence of hospital readmission events in the protocol group compared to the preprotocol group (1.0% vs. 4.7%, P=.013).

CONCLUSIONS

Compared to a historical cohort, a PTH-guided protocol for calcium and calcitriol supplementation significantly reduces postoperative hypocalcemia and hospital readmission rates, in patients undergoing total thyroidectomy.

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).

Evaluation and Management of Hypoparathyroidism Summary Statement and Guidelines from the Second International Workshop

This clinical practice guideline addresses the prevention, diagnosis, and management of hypoparathyroidism (HypoPT) and provides evidence-based recommendations. The HypoPT task forces included four teams with a total of 50 international experts including representatives from the sponsoring societies. A methodologist (GG) and his team supported the taskforces and conducted the systematic reviews. A formal process following the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology and the systematic reviews provided the structure for seven of the guideline recommendations. The task force used a less structured approach based on narrative reviews for 20 non-GRADEd recommendations. Clinicians may consider postsurgical HypoPT permanent if it persists for >12 months after surgery. To predict which patients will not develop permanent postsurgical HypoPT, we recommend evaluating serum PTH within 12 to 24 hours post total thyroidectomy (strong recommendation, moderate quality evidence). PTH > 10 pg/mL (1.05 pmol/L) virtually excludes long-term HypoPT. In individuals with nonsurgical HypoPT, genetic testing may be helpful in the presence of a positive family history of nonsurgical HypoPT, in the presence of syndromic features, or in individuals younger than 40 years. HypoPT can be associated with complications, including nephrocalcinosis, nephrolithiasis, renal insufficiency, cataracts, seizures, cardiac arrhythmias, ischemic heart disease, depression, and an increased risk of infection. Minimizing complications of HypoPT requires careful evaluation and close monitoring of laboratory indices. In patients with chronic HypoPT, the panel suggests conventional therapy with calcium and active vitamin D metabolites as first-line therapy (weak recommendation, low-quality evidence). When conventional therapy is deemed unsatisfactory, the panel considers the use of PTH. © 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).

Definition and diagnosis of postsurgical hypoparathyroidism after thyroid surgery: meta-analysis

Background

Postsurgical hypoparathyroidism (PH) is the most frequent complication after thyroid surgery. The aim of this systematic review and meta-analysis is to summarize a unifying definition of PH and to elucidate the best possible approach for early detection of PH.

Methods

A systematic review of the literature according to the PICO framework using Embase, PUBMED and the Cochrane library was carried out on 1 December 2021 followed by analysis for risk of bias, data extraction and meta-analysis. All studies addressing the definition of postoperative hypoparathyroidism and/or diagnostic approaches for early detection and diagnosis were included. Case reports, commentaries, non-English articles, book chapters and pilot studies and reviews were excluded.

Results

From 13 704 articles, 188 articles were eligible for inclusion and further analysis. These articles provided heterogeneous definitions of PH. Meta-analysis revealed that postoperative measurements of parathormone (PTH) levels have a higher sensitivity and specificity than intraoperative PTH measurements to predict PH after thyroid surgery. None of the timeframes analysed after surgery within the first postoperative day (POD1) was superior to predict the onset of PH. PTH levels of less than 15 pg/ml and less than 10 pg/ml are both reliable threshold levels to predict the postoperative onset of PH. A relative reduction of mean(s.d.) PTH levels from pre- to postoperative values of 73 (standard deviation 11) per cent may also be predictive for the development of PH. The estimation of calcium levels on POD1 are recommended.

Conclusion

PH is best defined as an undetectable or inappropriately low postoperative PTH level in the context of hypocalcaemia with or without hypocalcaemic symptoms. PTH levels should be measured after surgery within 24 h. Both threshold levels below 10 and 15 pg/ml or relative loss of PTH before/after thyroid surgery are reliable to predict the onset of PH.

Transoral endoscopic thyroidectomy by vestibular approach in Viet Nam: surgical outcomes and long-term follow-up

BACKGROUND

The transoral endoscopic thyroidectomy by vestibular approach (TOETVA) has been developed for early-stage thyroid cancer treatment as well as benign thyroid nodules worldwide including Viet Nam, with low rate of complications and excellent results. However, there has not been any comprehensive studies with a large number of patients and long-term follow-up in our country. Therefore, we conducted this study to evaluate the results of treatment by TOETVA for benign and malignant lesions of thyroid gland in Viet Nam.

METHODS

A prospective study was performed on 326 eligible patients who underwent TOETVA due to thyroid cancer and benign thyroid nodules in Department of Oncology and Palliative Care, Hanoi Medical University Hospital from July 2018 to April 2021. The clinical, surgical, and pathological characteristics, postoperative complications, and visual analog scale (VAS, 0-10 cm) score in day 1, 4, and 7 after surgery, long-term oncological and surgical outcomes were recorded.

RESULTS

The mean age was 36.9 ± 9.8 years. 231 patients (70.9%) were diagnosed with differentiated cancer and 95 patients (29.1%) were diagnosed benign tumors of thyroid gland. In the cancer group, 12 patients (5.2%) undergone TOETVA had T3b-intraoperative-stage diagnosis, 219 patients (92.2%) were diagnosed T1 according to AJCC 8th. After 1 month of surgery, among thyroid cancer patients, there was no abnormality reported by thyroid scintigraphy and neck ultrasound as well as in unstimulated-Tg and anti-Tg values. The mean number lymph-node dissected in the cancer group was 6.1 ± 4.1 (range 0-21 nodes). However, only 2.6 ± 1.8 metastasis nodes were discovered (range 1-8 nodes), and the maximum size of these nodes was less than 2 mm. 81 patients presented occult lymph-node metastasis among thyroid cancer patients with cN0 stage (account for 35%). The occult lymph-node metastasis was 34.2% and 50% in patients diagnosed with T1 and T3b groups, respectively. The median postoperative hospital stay was 5.4 ± 0.7 days. Postoperatively, transient hypoparathyroidism was recorded in 12 patients (4.8%), transient hoarse was noted in 9 patients (3.6%), and numb chin was identified in 7 patients (2.8%). No permanent complication was noted. VAS score on first postoperative day was 4.5 ± 0.8. Median follow-up time was 12 (3-25) months. No recurrence was recorded.

CONCLUSIONS

TOETVA is an innovative and revolutionary technique in the treatment of benign thyroid nodules, as well as early-stage differentiated thyroid cancer. The results of oncology, postoperative complications, and satisfied outcomes supported the wide application of TOETVA in Viet Nam.

Early Postoperative Parathormone and Calcium as Prognostic Factors for Postoperative Hypocalcemia

BACKGROUND

Postoperative hypocalcemia is one of the most common complications after total thyroidectomy. Parathormone (PTH) and calcium levels, measured several hours after surgery, have been suggested as valuable markers for detecting patients at risk for post-thyroidectomy hypocalcemia. We aimed to determine if early post-surgery PTH and calcium levels can be used for the early identification of patients at risk for symptomatic hypocalcemia.

METHODS

PTH and calcium were measured before surgery and at 10 min and 4 h post-thyroidectomy, in 77 patients. Performance characteristics of PTH and calcium levels and their post/pre-surgery ratios were calculated.

RESULTS

Four-hour calcium was a sensitive (93.75%) but not specific (67.61%) indicator of patients at risk for symptomatic hypocalcemia. The 4-h/pre-surgery PTH ratio was the most accurate (90.81%) and the most specific (94.37%) test to identify patients at risk. Serum calcium at 4-h, 4-h/pre-surgery PTH ratio, and PTH at 10 min post-surgery had the higher diagnostic odds ratios (50.86, 32.85, and 29.04, respectively). The 4-h/pre-surgery PTH ratio also had the highest (0.694) Youden's J statistic.

CONCLUSIONS

Low serum calcium levels 4 h after thyroidectomy and the 4-h/pre-surgery PTH ratio could be valuable additions to everyday clinical practice in post-thyroidectomy patients.

Questionable value of [99mTc]-sestamibi scintigraphy in patients with pHPT and negative ultrasound

PURPOSE

A successful focused surgical approach in primary hyperparathyroidism (pHPT) relies on accurate preoperative localization of the parathyroid adenoma (PA). Most often, ultrasound is followed by [^99mTc]-sestamibi scintigraphy, but the value of this approach is disputed. Here, we evaluated the diagnostic approach in patients with surgically treated pHPT in our center with the aim to further refine preoperative diagnostic procedures.

METHODS

A single-center retrospective analysis of patients with pHPT from 01/2005 to 08/2021 was carried out followed by evaluation of the preoperative imaging modalities to localize PA. The localization of the PA had to be confirmed intraoperatively by the fresh frozen section and significant dropping of the intraoperative parathyroid hormone (PTH) levels.

RESULTS

From 658 patients diagnosed with pHPT, 30 patients were excluded from the analysis because of surgery for recurrent or persistent disease. Median age of patients was 58.0 (13-93) years and 71% were female. Neck ultrasound was carried out in 91.7% and localized a PA in 76.6%. In 23.4% (135/576) of the patients, preoperative neck ultrasound did not detect a PA. In this group, [^99mTc]-sestamibi correctly identified PA in only 25.4% of patients. In contrast, in the same cohort, the use of [¹¹C]-methionine or [¹¹C]-choline PET resulted in the correct identification of PA in 79.4% of patients (OR 13.23; 95% CI 5.24-33.56).

CONCLUSION

[¹¹C]-Methionine or [¹¹C]-choline PET/CT are superior second-line imaging methods to select patients for a focused surgical approach when previous ultrasound failed to identify PA.

Predicting risk factors of postoperative hypocalcemia after total thyroidectomy: is safe discharge without supplementation possible? A large cohort study

PURPOSE

With increasing economic pressures to shorten the length of hospital stay, there has been much recent interest in studying risk factors for the development of postoperative hypocalcemia after total thyroidectomy. The aim of this study was to investigate whether serum calcium and/or PTH levels can predict post-thyroidectomy hypoparathyroidism.

METHODS

From January to December 2014, 477 consecutive patients undergoing total thyroidectomy were included. Corrected calcemia and PTH were systematically performed on postoperative day 1/(POD1). Symptomatic patients were treated on POD1 or POD2 with calcium and vitamin D.

RESULTS

Sixty-eight patients (14.25%) were treated for postoperative hypocalcemia. No patients with calcemia ≥ 2.16 mmol/l and PTH ≥ 1.9 pmol/l were supplemented and therefore were safely discharged on POD1 (specificity = 100%). All patients with calcemia ≤ 1.89 mmol/l were treated regardless the PTH values (n = 10) (specificity = 100%). For calcium value between 1.9 and 2.16 mmol/l with a PTH > 4.7 pmol/l, nobody was treated. With a calcemia between 1.9 and 2.16 mmol/l and a PTH > 1.9 pmol/l, 44 patients did not develop any symptom. ROC curve analysis showed that combination of Cac = 2.16 mmol/l and iPTH = 4.7 pmol/l provided a sensitivity of 97.06% and a specificity of 76.53% (p < 0.0001). We therefore propose an algorithm that would allow to 70% of patients could have been discharged on POD1 without risk of hypocalcemia or overtreatment.

CONCLUSION

Combination of corrected calcemia and PTH on POD1 can efficiently predict hypocalcemia and be integrated into clinical practice for personalizing lengths of hospitalization and appropriate treatment.

TRIAL REGISTRATION

ClinicalTrials.gov PRS. Unique Identifying number or registration ID: NCT04372225.

Does number of autotransplanted parathyroid glands affects postoperative hypoparathyroidism and serum parathyroid hormone levels?

BACKGROUND

To investigate how number of autotransplanted parathyroid glands (PGs) affects the incidence of postoperative hypoparathyroidism and the recovery of parathyroid function.

METHODS

A systematic search was performed in the MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases. The evaluated indices included the incidence of postoperative transient and permanent hypoparathyroidism and parathyroid hormone (PTH) levels during follow-up.

RESULTS

Twenty articles with 7291 patients were included. A higher incidence of transient hypoparathyroidism was found in the PG autotransplantation group than in the preservation group (odds ratio [OR]: 2.37; 95% confidence interval [CI]: 1.90, 2.96). However, there was no significant difference between the two groups regarding permanent hypoparathyroidism (OR: 1.17; 95% CI: 0.71, 1.91). Parathyroid hormone (PTH) levels in the PG autotransplantation group changed significantly more than the preservation group at postoperative 1-day and 1-month, but became similar at the 6-month, 1-year and 2-year follow-up. Autotransplantation of 2 and 3 PGs demonstrated a higher incidence of transient hypoparathyroidism than 1 PG (OR: 2.09; 95% CI: 1.41, 3.11 and OR: 9.70; 95% CI: 2.11, 44.39, respectively), but no significant difference was observed between the autotransplantation of 3 and 2 PGs (OR: 0.99; 95% CI: 0.03, 29.06). Additionally, the incidence of permanent hypoparathyroidism was not significantly different when different number of PGs was autotransplanted.

CONCLUSIONS

PG autotransplantation is an effective mid- and long-term strategy for the preservation of parathyroid function. Although transient hypoparathyroidism was positively correlated with the number of autotransplanted PGs, no remarkable correlation was observed for permanent hypoparathyroidism.

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.

[Postoperative hypocalcemia - the most common complication of endocrine head and neck surgery: acute management]

BACKGROUND

In Germany, 8000 patients are affected by postoperative hypoparathyroidism per year following surgery of the thyroid gland, parathyroidal glands and the larynx. Patients do not only suffer from paresthesia in the acute phase of this complication, but are also adversely affected by the fear of loss of control following episodes of tetany even years after the first episode.

OBJECTIVES

Discussion of a diagnostic pathway and presentation of a management pathway for postoperative hypocalcemia.

METHODS

Narrative review, analysis and discussion of current literature and expert recommendations.

RESULTS

Early determination of calcium and parathyroid hormone allows timely diagnosis and treatment of postoperative hypoparathyroidism. Active vitamin D is pivotal for the resorption of calcium. Only the combined treatment with active vitamin D and calcium can mitigate or prevent the postoperative drop of calcium levels.

CONCLUSIONS

A standard operating procedure (SOP) for postoperative hypoparathyroidism should be implemented in every surgical department. An SOP for diagnosis and treatment of postoperative hypoparathyroidism is proposed for institutional individualization and implementation.

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.

Surgical strategy when identifying less than four parathyroid glands during total thyroidectomy: a retrospective cohort study

Background

Parathyroid glands protection is still controversial in patients with less than 4 parathyroid glands during thyroidectomy. The aim of this study was to investigate the strategy of parathyroid autotransplantation or in situ preservation in patients with 3 parathyroid glands.

Methods

Consecutive patients who underwent primary total thyroidectomy with bilateral central neck dissection for papillary thyroid carcinoma (PTC) in our center were included retrospectively. Serum calcium and parathyroid hormone (PTH) levels (pg/mL), incidence of hypocalcemia and hypoparathyroidism during 24 months follow-up were compared grouping by the number of parathyroid glands both identified intraoperatively and confirmed postoperatively by pathology.

Results

A total of 1,424 patients were included. Serum PTH and calcium levels were lower and the incidence of hypocalcemia was higher in patients with 3 identified parathyroid glands. When excluding patients with accidental parathyroid resection, the results remained similar. Of the 212 patients with 3 identified parathyroid glands, PTH levels at postoperative 12-month in patients underwent autotransplantation were significantly lower than patients with all parathyroid glands preserved in situ (3.65±1.30 vs. 4.67±1.89, P=0.026).

Conclusions

The parathyroid function was weaker in patients with 3 parathyroid glands than patients with 4 before and after operation. Parathyroid glands preserved all in situ promoted better recovery of postoperative function in patients with 3 identified parathyroid glands.

Development and validation of a new model for predicting hypocalcaemia after total thyroidectomy: the NuGra model

BACKGROUND

Hypocalcaemia is the most frequent complication after total thyroidectomy. Finding a method for its early detection has become a priority. A single-center prospective cohort study was conducted to identify risk factors for postoperative hypocalcaemia, develop an early detection model, and test its validity in a different group of patients.

METHODS

The sample was composed of patients who underwent a total thyroidectomy between May 2012 and September 2015. Demographic, clinical, laboratory, and surgical data were collected. The incidence of hypocalcaemia and permanent hypoparathyroidism was calculated. Bivariate and multivariate analysis identified several independent predictors of hypocalcaemia, which were used to design a predictive model. The validity of the model was subsequently tested in a different cohort. Area under the ROC curve (AUROC) was calculated to determine its predictive power.

RESULTS

The study and validation groups included 352 and 118 patients, respectively. Seventy-three patients developed laboratory-confirmed hypocalcaemia (20.7%), and symptomatic in 43 (12.2%). Multivariate analysis confirmed as independent predictors of hypocalcaemia the higher number of parathyroid glands identified [OR 1.41(0.98, 2.02); p = 0.063] and pre-to-postoperative gradient of parathormone decline [OR 1.06(1.04, 1.08); p < 0.001]. Based on these variables, the NuGra (Number of parathyroid glands identified-Gradient of decline) model was developed for predicting laboratory-confirmed hypocalcaemia. Its predictive power was high (AUROC 0.902, CI 0.857-0.947) for the study and the validation group (AUROC 0.956, CI 0.919-0.993).

CONCLUSIONS

A higher number of parathyroid glands identified and a higher gradient of parathormone decline are risk factors for post-thyroidectomy hypocalcaemia. The NuGra model is useful for early prediction of individual risk for hypocalcaemia.

Transoral Endoscopic Thyroidectomy by Vestibular Approach with Central Lymph Node Dissection for Thyroid Microcarcinoma

Background: The transoral endoscopic thyroidectomy by vestibular approach (TOETVA) has been developed for thyroid microcarcinoma (TMC) treatment worldwide, with low rate of complications and excellent oncological results. However, this approach has still not been routinely performed. Thus, in this study, we aim to demonstrate the feasibility and safety of this technique in the clinical practice. Methods: In this prospective cohort study, 29 patients diagnosed TMC and clinically node negative underwent thyroidectomy and prophylactic central lymph node dissection by TOETVA. The clinicopathologic characteristics, surgical outcomes, and cosmetic results were evaluated. Results: The mean age was 34.7 ± 8.5 years. Three patients had underlying Grave's disease. Thyroid lobectomy with isthmusectomy was performed in the majority of cases (72.4%). All patients underwent prophylactic central node dissection. The mean number of retrieved central node was 7.8 ± 3.7 (3-19). Seven patients (24.1%) had lymph node metastasis in postoperative pathology. Among them, the mean number of metastatic lymph nodes was 2.1 ± 1.7 (1-5). The mean operative time was 121.2 ± 22.6 minutes. Four patients experienced transient hoarse and 1 patient had hematoma. Visual analog scale score on first postoperative day was 2.8 ± 1.4 (0-5). Most of patients were satisfied with cosmetic outcome. Conclusions: The TOETVA is new technique for TMC in Vietnam. The initial results of oncology, postoperative complications, and cosmetic supported the application of TOETVA in TMC.

Prediction of post-idroidectomy hypocalcemia through rapid PTH determination

INTRODUCTION

Hypocalcemia is the most frequent complication after thyroidectomy. The aim of this work is to identify biochemical risk factors of hypocalcemia using quick perioperative (pre and post-thyroidectomy) intact parathyroid hormone (PTHi) and postoperative calcemias.

METHODS

In a consecutive series of 310 total thyroidectomies, samples of quick PTHi at the anaesthetic induction and 10 minutes after surgery, together with serum calcemias every 12 hours were obtained. The sensitivity, specificity, positive and negative predictive value are analyzed and related to hypocalcemia. A control group of hemithyroidectomies is also analyzed to compare the effects of surgery on PTH secretion.

RESULTS

Of the 310 patients, 202 (65.1%) remained normocalcemic and asymptomatic (group A), 108 (34.9%) presented hypocalcemia (Group B), requiring oral calcium (79 symptomatic). After analysis of several cut-off points, combining a PTHr drop gradient of 60% or calcemia inferior to 7.4 mg/dl at 24 hours, a sensitivity of 100% is achieved without leaving false negatives. Compared to the control group, there is a significant difference with respect to the post-operative calcemias and PTHr, p < 0.001.

CONCLUSIONS

Total thyroidectomy affects parathyroid function with evident decrease in rPTH and risk of hypocalcemia. The combination of PTHr decrease of 60% or less than 7.4 mg/dl calcemia at 24 hours gives a 100% sensitivity for predicting patients at risk of hypocalcemia.

Combined ionized calcium and PTH evaluation in the management of post-thyroidectomy hypocalcemia

BACKGROUND

The aim of our study was to investigate the postoperative course of calcium and parathyroid hormone (PTH) levels after total thyroidectomy to define a proper and low cost protocol.

METHODS

We studied 144 patients who underwent total thyroidectomy between 2007 and 2010. Ionized calcium was determined preoperatively and on day 1 (POD1), day 2 (POD2) and day 7 (POD7) postoperatively; PTH preoperatively and on POD7. Patients with ionized calcium ≤1.11 mmol/L were considered hypocalcemic and treated only if symptoms, ≤1 mmol/L were treated in all cases.

RESULTS

Ionized calcium and PTH declined postoperative in all patients compared to preoperative levels (P=0.000). Ionized calcium increased on POD7 compared to POD1 and POD2 (P=0.000). All hypocalcemic untreated 30 patients returned normocalcemic on POD7. Thirty-eight hypocalcemic patients were treated but 23 (61%) safely suspended therapy on POD7. We tested PTH and ionized calcium as independent factors of prolonged hypocalcemia (that required therapy beyond 7 days) with the following results (sensitivity, specificity, positive predictive value, negative predictive value and overall accuracy): PTH ≤11 pg/mL (80%, 100%, 100%, 96% and 97%, respectively), ionized calcium ≤1.11 mmol/L (80%, 88%, 59%, 95%, and 87%, respectively) and ionized calcium ≤1 mmol/L (28%, 100%, 100%, 87% and 88%, respectively).

CONCLUSIONS

Our data show that our protocol, including serum ionized calcium on 1^st, 2^nd, 7^th days and PTH on 7^th day after surgery, is safe and low cost and therefore may be useful in the post-surgical management of total thyroidectomy.

Effects of active localization and vascular preservation of inferior parathyroid glands in central neck dissection for papillary thyroid carcinoma

Background

The purpose of present study is to assess the effects of active localization and vascular preservation of inferior parathyroid glands in central neck dissection (CND) for papillary thyroid carcinoma (PTC).

Methods

A classification of IPGs according to their location and vascular features was developed, and, based on this classification, a CND procedure was designed, and IPGs and their vascular were actively localized and strategically preserved. A total of 197 patients with PTC who underwent a total thyroidectomy and concomitant CND were enrolled. Eighty-nine patients with traditional meticulous fascia dissection were allocated to group A, and 108 patients with active location and vascular preservation of IPGs were allocated to group B. Those with inferior parathyroid glands auto-transplantation in each group were assigned as group At (18) and group Bt (12). Variables including serum intact parathyroid hormone (PTH), total calcium, the incidence of transient, and permanent hypoparathyroidism were studied.

Results

Compared with group A, serum intact PTH (P < 0.001) and total calcium levels (P < 0.05) in group B significantly improved on the first postoperative day, and the incidence of transient hypoparathyroidism significantly dropped in group B (P < 0.001). A total of 170 patients in the two groups had complete follow-up data. The incidence of permanent hypoparathyroidism significantly decreased in group B, from 8.8% to 1.0% (P = 0.017). However, there were no significant differences in all variables between group Bt and group At.

Conclusion

Active location and vascular preservation of inferior parathyroid glands effectively protected the function of IPGs in CND for PTC.

The American Association of Endocrine Surgeons Guidelines for the Definitive Surgical Management of Thyroid Disease in Adults

OBJECTIVE

To develop evidence-based recommendations for safe, effective, and appropriate thyroidectomy.

BACKGROUND

Surgical management of thyroid disease has evolved considerably over several decades leading to variability in rendered care. Over 100,000 thyroid operations are performed annually in the US.

METHODS

The medical literature from 1/1/1985 to 11/9/2018 was reviewed by a panel of 19 experts in thyroid disorders representing multiple disciplines. The authors used the best available evidence to construct surgical management recommendations. Levels of evidence were determined using the American College of Physicians grading system, and management recommendations were discussed to consensus. Members of the American Association of Endocrine Surgeons reviewed and commented on preliminary drafts of the content.

RESULTS

These clinical guidelines analyze the indications for thyroidectomy as well as its definitions, technique, morbidity, and outcomes. Specific topics include Pathogenesis and Epidemiology, Initial Evaluation, Imaging, Fine Needle Aspiration Biopsy Diagnosis, Molecular Testing, Indications, Extent and Outcomes of Surgery, Preoperative Care, Initial Thyroidectomy, Perioperative Tissue Diagnosis, Nodal Dissection, Concurrent Parathyroidectomy, Hyperthyroid Conditions, Goiter, Adjuncts and Approaches to Thyroidectomy, Laryngology, Familial Thyroid Cancer, Postoperative Care and Complications, Cancer Management, and Reoperation.

CONCLUSIONS

Evidence-based guidelines were created to assist clinicians in the optimal surgical management of thyroid disease.

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.

FIRST DAY SERUM CALCIUM AND PARATHYROID HORMONE LEVELS AS PREDICTIVE FACTORS FOR SAFE DISCHARGE AFTER THYROIDECTOMY

Context

Permanent hypocalcemia is a rare but significant complication of thyroid surgery.

Objective

The aim of this study was to identify predictive factors of hypocalcemia and hypoparathyroidism after thyroidectomy.

Design

Study included 134 total patients submitted to thyroidectomy from two endocrine units (January 2015 - August 2016).

Methods

We measured total serum calcium (sCa) and intact PTH (iPTH) on postoperative day one and 1 month after surgery.

Results

118 patients were women with F/M ratio of 7.3/1 and a mean age of 51.8 years. 64 patients were included in group A (iPTH <12 pg/mL) and 70 patients in group B (iPTH >12 pg/mL). sCa and hypocalcemia symptoms were correlated with iPTH, measured 24 hours after surgery. The cut-off value was for sCa 8.05 mg/dL with a sensitivity of 85.29% and a specificity of 88.0% and for iPTH 11.2 pg/mL, with a sensitivity of 82.3% and a specificity of 71.0%. SCa (< 8.05 mg/dL) was a predictive factor with a 99 (IC95%:12.86-761.58) and iPTH (<11.2 pg/mL) with a 10.77 higher risk (CI95%: 3.83-30.30) to be associated with symptoms.

Conclusion

SCa and iPTH represent good predictive factors of early and safe hospital discharge and can predict the risk of prolonged and permanent hypoparathyroidism.

Routine low-dose calcium supplementation after thyroidectomy does not reduce the rate of symptomatic hypocalcemia: a prospective randomized trial

Purpose

Routine supplementation of high-dose calcium significantly decreased the risk of postoperative symptomatic hypocalcemia after thyroidectomy. However, there is an ongoing debate about whether the same results can be achieved with low-dose calcium supplementation.

Methods

Patients (n = 138) who underwent total thyroidectomy for thyroid cancer were 1:1 randomly assigned to receive oral supplements of 1,500 mg/day elemental calcium and 1,000 IU/day cholecalciferol for 2 weeks or no supplementation. Primary objective was to compare the incidence of symptomatic hypocalcemia for 3 days after total thyroidectomy. Secondary objective was to find the predictors for postoperative hypocalcemia in patients with thyroid cancer.

Results

Sixty-five patients in the calcium group and 69 patients in the control group were finally analyzed. The incidence of symptomatic hypocalcemia showed no difference between the calcium and control group (32.3% vs. 21.7%, P = 0.168). The total dosage of intravenous calcium (593.4 ± 267.1 mg vs. 731.6 ± 622.7 mg, P = 0.430) administered to patients with symptomatic hypocalcemia was also comparable between groups. In a multivariate analysis, parathyroid hormone level of 13 pg/mL at postoperative day 1 was only predictive for symptomatic hypocalcemia, and its incidence was 20.9 times (95% confidence interval, 6.8-64.5) higher in patients with parathyroid hormone <13 pg/mL. Other factors did not predict the development of hypocalcemia, including clinicopathological features and routine supplementation of low-dose calcium.

Conclusion

Routine low-dose calcium supplementation did not reduce the risk of postoperative hypocalcemia. Patients who may benefit from calcium supplementation should be carefully selected.

Clinical Utility of Intraoperative Parathyroid Hormone Measurement in Children and Adolescents Undergoing Total Thyroidectomy

Background: Hypoparathyroidism is one of the most common complications for patients undergoing total thyroidectomy. Our study's primary objective was to assess if intraoperative PTH levels correlate with parathyroid gland function recovery time in pediatric patients following total thyroidectomy. Methods: Retrospective review of pediatric patients who underwent thyroid surgery at CHOP for demographics and laboratory test values (calcium, phosphorus, and parathyroid hormone). We defined Time of Recovery (TOR) as the time difference from first intra-operative parathyroid hormone level (ioPTH) timepoint until normalization of PTH (> 10 pg/mL) post-thyroidectomy. Calcium and vitamin D supplements were weaned following normalization of calcium and phosphorous levels postoperatively. Patients were excluded if they lacked three intraoperative PTH timepoints or were missing postoperative follow-up PTH data. Results: 65 patients (54 female), median age 15 (range 5-23 years), underwent thyroid surgery and met study inclusion criteria. The correlations of 2nd and 3rd ioPTHs with TOR were statistically significant (p < 0.05): the lower the ioPTH, the greater the recovery time. Stratifying patients into high-risk (2nd ioPTH ≤ 10 pg/mL), moderate-risk (2nd ioPTH between 10 and 20 pg/mL), and low-risk (2nd ioPTH ≥ 20 pg/mL) tertiles, the TOR decreased by orders of magnitudes from an average of 43.13 ± 76.00 to 6.10 ± 17.44 to 1.85 ± 6.20 days. These differences were statistically significant (p < 0.05). Conclusions: Our study results confirm the usefulness of intraoperative PTH levels to predict pediatric patient recovery post-surgery and provides useful anticipatory guidance to optimize timing and frequency of postoperative laboratory surveillance.

The timing of parathyroid hormone measurement defines the cut-off values to accurately predict postoperative hypocalcemia: a prospective study

PURPOSE

Serum intact parathyroid hormone (iPTH) level is an early marker of post-thyroidectomy hypocalcemia. However, lack of methodological standardization to define timing and cut-off points of iPTH measurement limit its clinical applicability. Here, we evaluated the relationship between two distinct postoperative time sampling and iPTH accuracy on predicting hypocalcemia.

METHODS

iPTH was measured within 4 h after surgery (iPTH 4 h) and on the morning of the first postoperative day (iPTH 1st PO). Hypocalcemia was defined by levels of total calcium corrected by serum albumin ≤ 8.0 mg/dL and/or by the presence of symptoms. The most accurate iPTH cut-off point for hypocalcemia prediction was established from a ROC curve comparing both time-points.

RESULTS

The study included 101 patients. The mean age was 52.4 ± 12.9 years, 93 were women (92.1%) and 69 patients underwent total thyroidectomy (68.3%). Hypocalcemia occurred in 25 patients (24.8%), of whom 12 were symptomatic. Total thyroidectomy, longer duration of surgery, surgical complications related to parathyroid glands and lower levels of iPTH 4 h and iPTH 1st PO were associated with postoperative hypocalcaemia (all P < 0.05). Using the ROC curve, the optimal cut-off points were 19.55 pg/mL and 14.35 pg/mL for iPTH 4 h and iPTH 1st PO, respectively. The comparison of the AUC showed no significant difference between these two points of evaluation (0.935 vs. 0.940; P = 0.415).

CONCLUSIONS

Serum iPTH levels measured within 4 h or on the first morning after surgery are predictors of postoperative hypocalcemia. Notably, both time-points have the same accuracy to predict postoperative hypocalcemia (with different cutoff points).

American Thyroid Association Statement on Postoperative Hypoparathyroidism: Diagnosis, Prevention, and Management in Adults

BACKGROUND

Hypoparathyroidism (hypoPT) is the most common complication following bilateral thyroid operations. Thyroid surgeons must employ strategies for minimizing and preventing post-thyroidectomy hypoPT. The objective of this American Thyroid Association Surgical Affairs Committee Statement is to provide an overview of its diagnosis, prevention, and treatment.

SUMMARY

HypoPT occurs when a low intact parathyroid hormone (PTH) level is accompanied by hypocalcemia. Risk factors for post-thyroidectomy hypoPT include bilateral thyroid operations, autoimmune thyroid disease, central neck dissection, substernal goiter, surgeon inexperience, and malabsorptive conditions. Medical and surgical strategies to minimize perioperative hypoPT include optimizing vitamin D levels, preserving parathyroid blood supply, and autotransplanting ischemic parathyroid glands. Measurement of intraoperative or early postoperative intact PTH levels following thyroidectomy can help guide patient management. In general, a postoperative PTH level <15 pg/mL indicates increased risk for acute hypoPT. Effective management of mild to moderate potential or actual postoperative hypoPT can be achieved by administering either empiric/prophylactic oral calcium and vitamin D, selective oral calcium, and vitamin D based on rapid postoperative PTH level(s), or serial serum calcium levels as a guide. Monitoring for rebound hypercalcemia is necessary to avoid metabolic and renal complications. For more severe hypocalcemia, inpatient management may be necessary. Permanent hypoPT has long-term consequences for both objective and subjective well-being, and should be prevented whenever possible.

The Impact of Postoperative Percent Change of Parathormone Level From Baseline Value on the Rate of Hypocalcemia After Total Thyroidectomy

Background

The purpose of this study was to investigate the impact of the percent change of postoperative parathormone (PoPTH) level from baseline value (ΔPTH) on the rate of hypocalcemia after total thyroidectomy.

Methods

Assays of serum PTH and calcium (Ca) were performed preoperatively and at 24 hours postoperatively in 222 consecutive patients who underwent total thyroidectomy. Postoperative hypocalcemia was defined as serum calcium level corrected for albumin concentration (cCa) &lt;8.5 mg/dL. Patients with postoperative hypocalcemia were classified as group 1 (n = 100) and those with normal Ca levels as group 2 (n = 122). The PoPTH levels and ΔPTH were compared between the 2 groups. Receiver operating characteristic analysis was performed to determine the cutoff values for PoPTH and ΔPTH.

Results

The mean PoPTH level was significantly lower in group 1 compared with group 2 (18.6 ± 15.3 versus 32.3 ± 15.6 pg/mL, respectively; P &lt; 0.0001). PoPTH values were within the normal range in 54% of the patients with hypocalcemia and 35% of those with symptomatic hypocalcemia. PoPTH &lt;28 pg/mL or ΔPTH &gt;45 were significantly associated with increased risk of post-thyroidectomy hypocalcemia (P = 0.0001). A ΔPTH &gt;70%, PoPTH ≤15.5 pg/mL, and postoperative serum cCa concentrations&lt;8.0 mg/dL significantly predicted symptomatic hypocalcemia (P = 0.009, P = 0.006, and P = 0.0001, respectively). The sensitivities of ΔPTH, PoPTH level, and postoperative serum cCa concentration to predict symptomatic hypocalcemia were 67%, 64%, and 100%, respectively.

Conclusion

Although PTH decline significantly correlates with symptomatic hypocalcemia, a considerable number of patients may experience hypocalcemic symptoms despite normal PoPTH levels. Analysis of serum Ca concentrations at 24 hours postoperatively help to achieve a more precise prediction of patients who bear a high risk for developing hypocalcemic symptoms.

Failure of fragmented parathyroid gland autotransplantation to prevent permanent hypoparathyroidism after total thyroidectomy

PURPOSE

Parathyroid autotransplantation during total thyroidectomy leads to higher rates of postoperative hypocalcaemia. It has been argued, however, that it prevents permanent hypoparathyroidism. The impact of autografted normal parathyroid gland fragments on long-term parathyroid status has not been assessed properly. To clarify this, the short- and long-term parathyroid function was assessed in patients with three glands remaining in situ after total thyroidectomy, in whom the fourth gland was either autotransplanted (Tx) or accidentally resected (AR).

METHODS

Consecutive patients (n = 669) undergoing first-time total thyroidectomy were prospectively studied recording the number of parathyroid glands remaining in situ: PGRIS =4-(glands autografted + glands in the specimen). The study was focused on the subgroup of 186 patients with three parathyroid glands remaining in situ as a result of either accidental resection (AR, n = 76) or autotransplantation into the sternocleidomastoid muscle (Tx, n = 110). Prevalence of postoperative hypocalcaemia, protracted, and permanent hypoparathyroidism were compared between the two groups. Demographic, disease-related, laboratory, and surgical variables were recorded. All patients were followed for at least 1 year.

RESULTS

Both groups were comparable in terms of disease and extent of surgery. Mean postoperative serum calcium was the same (AR: 1.97 ± 0.2 vs Tx: 1.97 ± 0.22 mmol/L). Rates of protracted (AR: 24% vs Tx: 25.5%) and permanent hypoparathyroidism (AR: 5.3% vs Tx: 7.3%) were similar in both groups.

CONCLUSIONS

The prevalence of parathyroid failure syndromes after total thyroidectomy was similar whether a parathyroid gland was inadvertently excised or autotransplanted. Autotransplantation did not influence the permanent hypoparathyroidism rate.

Parathyroid Autotransplantation During Thyroid Surgery: A Novel Technique Using a Cell Culture Nutrient Solution

INTRODUCTION

Parathyroid autotransplantation is an easy procedure with a low complication rate. We adopted the transplantation into the sternocleidomastoid muscle, which allows an easier and time-saving surgical procedure using the same surgical incision.

METHODS

In this study, we retrospectively reviewed the records of 396 consecutive patients, who underwent total thyroidectomy for benign thyroid disease. In all cases in which a parathyroid was damaged or inadvertently removed, the gland was transplanted; before the autotransplantation, the parathyroid tissue was put in a cell culture nutrient solution for 5 min, afterward fragmented, and then was transplanted in the sternocleidomastoid muscle. To demonstrate a beneficial effect of the cell nutrient solution step, we compared data of transplanted patients with a control group of cases (n = 190) undergoing a standard immediate autotransplantation.

RESULTS

We divided patients in two main groups: group A (n = 160) including subjects that underwent one or more parathyroid gland autotransplantation using the cell nutrient solution, and group B (n = 236) concerning those who were not transplanted. Among patients, 62 hypocalcemias occurred, 40 in the group A and 22 in the group B (P < 0.001): 91.9 % were transient and 8.1 % (5 patients) definitive, all pertaining to the group B. Among controls (group C), 42 hypocalcemias occurred (P = 0.616 vs. group A and P = 0.002 vs. group B) and 3/42 became definitive (P = 0.096 vs. group A and P = 0.121 vs. group B). All differences concerning pre- and postoperative calcium values were statistically significant (P < 0.001).

CONCLUSIONS

We recommend the routine parathyroid autotransplantation, when a vascular damage is certain or suspected, in order to reduce the rate of permanent hypoparathyroidism, using a cell culture nutrient solution before gland transplantation.

Outcome of hypocalcaemia after thyroidectomy treated only in symptomatic patients

BACKGROUND

Calcium supplementation has been proposed after bilateral thyroid surgery, either to all patients or to those with biochemical hypocalcaemia. It has also been suggested that supplementation aids parathyroid recovery and prevents permanent hypoparathyroidism. This single-centre study investigated the feasibility of a restrictive management of post-thyroidectomy hypocalcaemia.

METHODS

Serum calcium was checked before surgery, on postoperative day 1 (POD) 1, at a follow-up visit 6-8 weeks after surgery and after a minimum of 12 months in all patients. Regardless of serum calcium levels, patients with symptoms of hypocalcaemia were prescribed oral calcium supplementation (0·5-1·0 g twice daily) and asymptomatic patients were not. Asymptomatic patients were informed about hypocalcaemic symptoms and instructed to contact the surgical ward should symptoms appear.

RESULTS

Some 640 patients underwent bilateral thyroid surgery without previous or intentional simultaneous parathyroidectomy. A subnormal serum calcium level (below 2·15 mmol/l) was observed in 412 patients (64·4 per cent) on POD 1. By comparison, only 63 patients (9·8 per cent) experienced symptoms of hypocalcaemia in the postoperative period, all but one with a corresponding biochemical hypocalcaemia on POD 1. Calcium levels in all patients with asymptomatic postoperative hypocalcaemia recovered to normal without supplementation. Serum calcium was also normalized during follow-up in all symptomatic patients, except 22 (3·4 per cent) who became permanently hypoparathyroid. No patient without early hypocalcaemic symptoms developed permanent hypoparathyroidism.

CONCLUSION

The proposed restrictive management of postoperative hypocalcaemia after bilateral thyroid surgery avoids unnecessary supplementation for most patients.

[Avoidance and management of hypoparathyroidism after thyroid gland surgery]

Postoperative hypoparathyroidism after bilateral thyroid gland surgery or after interventions for recurrence is defined as intact parathyroid hormone levels (iPTH) < 15 pg/ml with simultaneous normal, below normal and markedly decreased serum calcium levels. After bilateral thyroid surgery and after reoperations a single iPTH measurement performed 12-24 h postoperatively can be used to predict parathyroid metabolism. Patients with an iPTH level ≥ 15 pg/ml may be discharged safely, patients with an iPTH < 10 pg/ml must be substituted with calcium and vitamin D and patients with an iPTH between 10 and 15 pg/ml (grey zone) may be discharged if a second measurement 48 h after surgery documents an iPTH ≥ 15 pg/ml. This procedure increases the length of hospital stay. Patients in the (grey zone) must be substituted. The iPTH level and its course determine the necessity, dose and length of calcium and vitamin D substitution.

European Society of Endocrinology Clinical Guideline: Treatment of chronic hypoparathyroidism in adults

Hypoparathyroidism (HypoPT) is a rare (orphan) endocrine disease with low calcium and inappropriately low (insufficient) circulating parathyroid hormone levels, most often in adults secondary to thyroid surgery. Standard treatment is activated vitamin D analogues and calcium supplementation and not replacement of the lacking hormone, as in other hormonal deficiency states. The purpose of this guideline is to provide clinicians with guidance on the treatment and monitoring of chronic HypoPT in adults who do not have end-stage renal disease. We intend to draft a practical guideline, focusing on operationalized recommendations deemed to be useful in the daily management of patients. This guideline was developed and solely sponsored by The European Society of Endocrinology, supported by CBO (Dutch Institute for Health Care Improvement) and based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) principles as a methodological base. The clinical question on which the systematic literature search was based and for which available evidence was synthesized was: what is the best treatment for adult patients with chronic HypoPT? This systematic search found 1100 articles, which was reduced to 312 based on title and abstract. The working group assessed these for eligibility in more detail, and 32 full-text articles were assessed. For the final recommendations, other literature was also taken into account. Little evidence is available on how best to treat HypoPT. Data on quality of life and the risk of complications have just started to emerge, and clinical trials on how to optimize therapy are essentially non-existent. Most studies are of limited sample size, hampering firm conclusions. No studies are available relating target calcium levels with clinically relevant endpoints. Hence it is not possible to formulate recommendations based on strict evidence. This guideline is therefore mainly based on how patients are managed in clinical practice, as reported in small case series and based on the experiences of the authors.

Defining the syndromes of parathyroid failure after total thyroidectomy

Acute and chronic parathyroid insufficiency syndromes are the most common complication after total thyroidectomy. Permanent hypoparathyroidism imposes an important medical burden on patient lifestyle due to the need for lifetime medication, regular visits and significant long-term costs. Its true prevalence has been underestimated due to lack of clear definitions, inadequate follow-up and conflicts of interest when reporting individual patient series. The aim of this review is to propose precise definitions for the different syndromes associated to parathyroid failure based on the follow-up and management of patients developing hypocalcemia (<8 mg/dL at 24 hours) after first-time total thyroidectomy for cancer or goiter at our unit. Short and long-term post-thyroidectomy parathyroid failure presents as three different metabolic syndromes: (I) postoperative hypocalcemia is defined as a s-Ca <8 mg/dL (<2 mmol/L) within 24 hours after surgery requiring calcium/vit D replacement therapy at the time of hospital discharge; (II) protracted hypoparathyroidism as a subnormal iPTH concentration (<13 pg/mL) and/or need for calcium/vit D replacement at 4-6 weeks; and (III) permanent hypoparathyroidism as a subnormal iPTH concentration (<13 pg/mL) and/or need for calcium/vit D replacement 1 year after total thyroidectomy. Each of these syndromes has its own pattern of recovery and should be approached with different therapeutic strategies.

Importance of in situ preservation of parathyroid glands during total thyroidectomy

Background

Parathyroid failure is the most common complication after total thyroidectomy but factors involved are not completely understood. Accidental parathyroidectomy and parathyroid autotransplantation resulting in fewer than four parathyroid glands remaining in situ, and intensity of medical treatment of postoperative hypocalcaemia may have relevant roles. The aim of this study was to determine the relationship between the number of parathyroid glands remaining in situ and parathyroid failure after total thyroidectomy.

Methods

Consecutive patients undergoing first-time total thyroidectomy were studied prospectively, recording the number of Parathyroid Glands Remaining In Situ (PGRIS = 4 − (glands autografted + glands in the specimen)) and the occurrence of postoperative hypocalcaemia, and protracted and permanent hypoparathyroidism. Demographic, disease-related, laboratory and surgical variables were recorded. Patients were classified according to the PGRIS number into group 1–2 (one or two PGRIS), group 3 (three PGRIS) and group 4 (all four glands remaining in situ), and were followed for at least 1 year.

Results

A total of 657 patients were included, 43 in PGRIS group 1–2, 186 in group 3 and 428 in group 4. The prevalence of hypocalcaemia, and of protracted and permanent hypoparathyroidism was inversely related to the PGRIS score (group 1–2: 74, 44 and 16 per cent respectively; group 3: 51·1, 24·7 and 6·5 per cent; group 4: 35·3, 13·1 and 2·6 per cent; P &lt; 0·001). Intact parathyroid hormone concentrations at 24 h and 1 month were inversely correlated with PGRIS score (P &lt; 0·001). Logistic regression identified PGRIS score as the most powerful variable influencing acute and chronic parathyroid failure. In addition, a normal–high serum calcium concentration 1 month after thyroidectomy influenced positively the recovery rate from protracted hypoparathyroidism in all PGRIS categories.

Conclusion

In situ parathyroid preservation is critical in preventing permanent hypoparathyroidism after total thyroidectomy. Active medical treatment of postoperative hypocalcaemia has a positive synergistic effect.

Clinicopathological risk factors and biochemical predictors of safe discharge after total thyroidectomy and central compartment node dissection for thyroid cancer: a prospective study

To determine the clinicopathological risk factors and reliable biochemical predictors of the development of hypocalcemic symptoms after total thyroidectomy on the basis of serum calcium and intact parathyroid hormone (PTH) levels measured 1 hour after surgery, a prospective study was performed on 817 patients who underwent a total thyroidectomy with central compartment node dissection (CCND) due to well-differentiated thyroid cancer. We evaluated the correlations between hypocalcemic symptom development and clinicopathological factors. And the predictability for hypocalcemic symptom development of intact PTH cut-offs (<10 pg/mL and <20 pg/mL, resp.) according to serum calcium level subgroup was analyzed. Female gender (P < 0.001) was the only independent risk factor for hypocalcemic symptom development in multivariate regression analysis. The negative predictive value (NPV) of intact PTH, signifying nondevelopment of hypocalcemic symptoms, was higher than the positive predictive value (PPV) which signified development of hypocalcemic symptoms. In addition, when we applied the different adoption of the intact PTH cut-off according to serum calcium level, we could obtain more increased NPVs. A female gender and the application of more specific cut-offs for intact PTH according to the serum calcium levels measured 1 hour after surgery may help the patients to be more safely discharged.

Systematic review and meta-analysis of predictors of post-thyroidectomy hypocalcaemia

BACKGROUND

Hypocalcaemia is common after thyroidectomy. Accurate prediction and appropriate management may help reduce morbidity and hospital stay. The aim of this study was to perform a systematic literature review and meta-analysis of predictors of post-thyroidectomy hypocalcaemia.

METHODS

A systematic search of PubMed, EMBASE and the Cochrane Library databases was undertaken, and the quality of manuscripts assessed using a modified Newcastle-Ottawa Scale.

RESULTS

Some 115 observational studies were included. The median (i.q.r.) incidence of transient and permanent hypocalcaemia was 27 (19-38) and 1 (0-3) per cent respectively. Independent predictors of transient hypocalcaemia included levels of preoperative calcium, perioperative parathyroid hormone (PTH), preoperative 25-hydroxyvitamin D and postoperative magnesium. Clinical predictors included surgery for recurrent goitre and reoperation for bleeding. A calcium level lower than 1·88 mmol/l at 24 h after surgery, identification of fewer than two parathyroid glands (PTGs) at surgery, reoperation for bleeding, Graves' disease and heavier thyroid specimens were identified as independent predictors of permanent hypocalcaemia in multivariable analysis. Factors associated with transient hypocalcaemia in meta-analyses were inadvertent PTG excision (odds ratio (OR) 1·90, 95 per cent confidence interval 1·31 to 2·74), PTG autotransplantation (OR 2·03, 1·44 to 2·86), Graves' disease (OR 1·75, 1·34 to 2·28) and female sex (OR 2·28, 1·53 to 3·40).

CONCLUSION

Perioperative PTH, preoperative vitamin D and postoperative changes in calcium are biochemical predictors of post-thyroidectomy hypocalcaemia. Clinical predictors include female sex, Graves' disease, need for parathyroid autotransplantation and inadvertent excision of PTGs.

Do low preoperative vitamin D levels reduce the accuracy of quick parathyroid hormone in predicting postthyroidectomy hypocalcemia?

Background

Although some studies have suggested that low preoperative 25-hydroxyvitamin D (25-OHD) levels may increase the risk of hypocalcemia and decrease the accuracy of single quick parathyroid hormone in predicting hypocalcemia after total thyroidectomy, the literature remains scarce and inconsistent. Our study aimed to address these issues.

Methods

Of the 281 consecutive patients who underwent a total/completion total thyroidectomy, 244 (86.8 %) did not require any oral calcium and/or calcitriol supplements (group 1), while 37 (13.2 %) did (group 2) at hospital discharge. 25-OHD level was checked 1 day before surgery, and postoperative quick parathyroid hormone (PTH) was checked at skin closure (PTH-SC). Postoperative serum calcium was checked regularly. Hypocalcemia was defined by the presence of symptoms or adjusted calcium of <1.90 mmol/L. Significant factors for hypocalcemia were determined by univariate and multivariate analyses. The accuracy of PTH-SC in predicting hypocalcemia was measured by area under a receiver operating characteristic curve (AUC), and the AUC of PTH-SC was compared between patients with preoperative 25-OHD <15 and ≥15 ng/mL via bootstrapping.

Results

Preoperative 25-OHD level was not significantly different between groups 1 and 2 (13.1 vs. 12.5 ng/mL, p = 0.175). After adjusting for other significant factors, PTH-SC (odds ratio 2.49, 95 % confidence interval 1.52–4.07, p < 0.001) and parathyroid autotransplantation (odds ratio 3.23, 95 % confidence interval 1.22–8.60, p = 0.019) were the two independent factors for hypocalcemia. The AUC of PTH-SC was similar between those with 25-OHD <15 and ≥15 ng/mL (0.880 vs. 0.850, p = 0.61)

Conclusions

Low 25-OHD was not a significant factor for hypocalcemia and did not lower the accuracy of quick PTH in predicting postthyroidectomy hypocalcemia.

A prospective evaluation of quick intraoperative parathyroid hormone assay at the time of skin closure in predicting clinically relevant hypocalcemia after thyroidectomy

Background

Post-thyroidectomy hypocalcemia is a major contributing factor in delayed hospital discharge and dissuading surgeons from ambulatory thyroidectomy. We prospectively evaluated the accuracy and reliability of quick parathyroid hormone level measurement at skin closure (PTH-SC) in predicting clinically relevant hypocalcemia (i.e., patients requiring calcium ± calcitriol supplements on hospital discharge).

Methods

Of the 117 patients who underwent a total or completion total thyroidectomy and PTH-SC, 17 (14.5 %) had hypocalcemic symptoms or adjusted calcium <1.90 mmol/L requiring calcium and/or calcitriol supplements on discharge. Serum calcium was checked regularly in the perioperative period until stabilization and an additional quick PTH was checked on the following morning (PTH-D1). Univariate and multivariate analyses were performed to evaluate potential preoperative clinicopathologic factors and postoperative day 0 biochemical indicators. Youden’s index and the area under the ROC curve (AUC) were used to determine the best cutoff value and predictability of significant variables or criteria, respectively.

Results

In the multivariate analysis, low preoperative adjusted calcium (p = 0.041) and low PTH-SC (p = 0.001) were the two independent variables associated with hypocalcemia. PTH-SC (≤1 or >1 pmol/L) had a higher specificity (95.0 %) and AUC (0.887) than serial calcium monitoring or PTH-D1 alone. Although 3/98 of patients with PTH-SC >1 pmol/L required calcium supplements on discharge, they required only the minimum amount to maintain normocalcemia.

Conclusion

PTH-SC is an accurate and reliable means of predicting clinically relevant hypocalcemia. It would be reasonable to discharge those with PTH-SC >1 pmol/L on the same operative day as the risk of life-threatening hypocalcemia would seem unlikely.

Parathyroid function after open thyroidectomy: A prospective randomized study for ligasure precise versus harmonic FOCUS

BACKGROUND

Options for controlling hemostasis during thyroidectomy include bipolar vessel sealing system and ultrasonic technology. The purpose of this study was to compare these energy-based devices on the performance of open thyroidectomy for benign disease with emphasis given to postoperative parathyroid function.

METHODS

Among the available energy-based devices, the LigaSure Precise (LP; Valleylab, Boulder, CO) and FOCUS Shears (FS; Ethicon Endo-Surgery, Cincinnati, OH) were evaluated. One hundred ninety-nine consecutive patients scheduled for open thyroidectomy were prospectively randomized into 2 similar-sized groups. Operative time, morbidity, incision length, postoperative pain, and hospital stay were analyzed. Postoperative hypoparathyroidism was monitored with serial determinations of intact parathyroid hormone (iPTH) and serum calcium.

RESULTS

Early postoperative measurement of iPTH plasma level, although within the reference range, was significantly lower in the FS group (p < .001). Oral calcium supplementation was significantly higher and prolonged in the FS group.

CONCLUSION

The present study demonstrates a significant difference of the rates for postoperative parathyroid malfunction when using different energy-based devices.

The safety of energy-based devices in open thyroidectomy: a prospective, randomised study comparing the LigaSure™ (LF1212) and the Harmonic® FOCUS

PURPOSE

The options for haemostasis and dissection during modern thyroid surgery include the use of a bipolar vessel sealing system and ultrasonic technology. The aim of this study was to compare these energy-based devices (EBDs) with respect to their use in open thyroidectomy.

METHODS

The FOCUS Shear (F) and LigaSure LF1212 (L) were evaluated. A total of 182 consecutive patients scheduled for open thyroidectomy were prospectively randomised into two similarly sized groups. The parameters of operative time, morbidity, incision length, postoperative pain and hospital stay were analysed.

RESULTS

The main clinically primary endpoints of the two devices were identical in the study as the rate of nerve lesions, bleeding, drainage, operative time and postoperative calcium concentration with no significant differences with respect to the instrument utilised. The mean length of the incision was greater in the F group (p < 0.05). Patients in the F group were more likely to complain of pain while swallowing (p < 0.001). Early postoperative measurements of intact parathyroid hormone plasma levels revealed that although the levels were within the reference range, they were significantly lower in the F group (p < 0.001). Oral calcium supplementation was significantly higher and more prolonged in the F group.

CONCLUSIONS

The present study demonstrated no significant difference in the rates of postoperative morbidity associated with these two different EBDs used. Differences in clinically less significant were founded and focused on.

Outcome of protracted hypoparathyroidism after total thyroidectomy

BACKGROUND

Although the variables that influence the development of post-thyroidectomy hypocalcaemia are now better understood, the risk factors and long-term outcome of persistent hypoparathyroidism (HPP) are poorly defined. A retrospective review of a prospective protocol for the management of post-thyroidectomy hypocalcaemia was performed.

METHODS

Patients with a serum calcium level below 8 mg/dl (2 mmol/l) 24 h after total thyroidectomy were prescribed oral calcium with or without calcitriol and followed for at least 1 year. Protracted HPP was defined as an intact parathyroid hormone (iPTH) level below 13 pg/ml and need for calcium medication at 1 month after thyroidectomy.

RESULTS

Of 442 patients (343 with goitre, 99 with carcinoma) undergoing total thyroidectomy, 222 (50.2 per cent) developed postoperative hypocalcaemia. Eleven patients were lost to follow-up. Parathyroid function recovered in 131 patients within 1 month and 80 developed protracted HPP, which was associated with lymphadenectomy, fewer than three glands left in situ and incidental parathyroidectomy. Parathyroid function recovered within 1 year in 78 per cent of patients with protracted HPP. Factors associated with late recovery of parathyroid function were higher serum calcium and low but detectable iPTH levels 1 month after surgery. These factors were associated with higher calcitriol and calcium dosages at hospital discharge. Parathyroid autotransplantation did not protect against permanent HPP.

CONCLUSION

Higher serum calcium levels at 1 month after total thyroidectomy are associated with recovery of parathyroid function. It is hypothesized that intensive medical treatment of hypocalcaemia-'parathyroid splinting'-may improve the outcome of patients with protracted HPP.