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

An individual approach to intraoperative parathyroid hormone measurement during total thyroidectomy

PURPOSE

Hypocalcemia is a common complication of thyroidectomy. Measurement of the intraoperative serum parathyroid hormone (PTH) levels became an established technique but it requires further improvements. We aimed to assess intraoperative PTH level testing results against the hypothesis that the PTH assay may be performed almost immediately after thyroid gland removal.

METHODS

A retrospective cohort study. During total thyroidectomy surgery, the patients had PTH levels measured at the cutting time and again immediately after the thyroid gland is removed. Post-operatively, serial total blood calcium levels were obtained twice daily and recorded.

RESULTS

Among 63 enrolled patients, 39 had multinodular goiter, 15 thyroid carcinoma, and nine had Graves' disease. The mean age was 59.8 ± 15.3 years, 43 females. The mean PTH level before surgery was 45.8 ± 22.0 pg/mL. Post-operatively, 11/63 patients developed hypocalcemia with serum calcium levels <8 mg/dL. Four patients with ≥50 % decrease in PTH concentration were normocalcemic a day after surgery and were discharged early. Four patients with ≥70 % PTH decrease were treated accordingly during prolonged hospitalization and did not suffer from permanent hypocalcemia. The cut-off value of 70 % decrease after the gland removal was able to predict postoperative hypocalcemia with a sensitivity of 100 %, specificity 82.9 %, PPV 60.0 % and NPV 100 %.

CONCLUSION

Measurements of intraoperative PTH may not be performed at fixed time intervals but after 1-2 min after removal of the thyroid gland. Defining those not at risk would allow the majority of patients to be waived from post-operative blood calcium testing and safely discharged early after surgery.

Does preoperative calcium and 1, 25 OH vitamin D supplementation impact postoperative hypocalcemia and length of stay following pediatric thyroidectomy?

OBJECTIVE

To investigate whether perioperative calcium and 1,25 OH vitamin D supplementation (PCDS) influences the rates of postoperative hypocalcemia and length of stay (LOS) following pediatric thyroidectomy.

STUDY DESIGN

Retrospective Cohort Review.

SETTING

Tertiary children's hospital.

METHODS

94 patients who underwent completion or total thyroidectomy with or without concomitant neck dissection from 2010 to 2020 at a single institution were included. Patients with pre-existing hypocalcemia or preoperative vitamin D insufficiency were excluded. Rates of postoperative hypocalcemia and LOS were compared for patients receiving PCDS to those receiving no supplementation.

RESULTS

Thirty percent of patients with PCDS had documented postoperative hypocalcemia compared to 64% of patients without PCDS (p = 0.01). Patients with PCDS had a median LOS of 30 h compared to 36 h (p = 0.002). Multivariable analyses confirmed that patients with PCDS had lower odds of postoperative hypocalcemia (OR: 0.32, CI: 0.11, 0.89) and shorter LOS by 17 h (SE: 8, p = 0.04) after adjustment for confounders.

CONCLUSION

PCDS is associated with significantly lower risk of hypocalcemia and shorter LOS. Standardizing preoperative care for pediatric patients undergoing thyroidectomy may decrease variability and improve outcomes following surgery.

Management of hypocalcemia following thyroid surgery in children

Introduction

Pediatric post-thyroidectomy hypocalcemia management varies significantly from hospital to hospital. The current study has two aims: first, we evaluate demographic data in all pediatric patients submitted to thyroid surgery in our Spanish tertiary hospital over 20 years; secondly, we describe the way that hypocalcemia was diagnosed and treated in that period and present a multidisciplinary protocol for perioperative management of this condition.

Methods

This is a retrospective and observational study of all patients from 0 to 16 years old who underwent thyroid surgery from 2000 to 2020 at our institution. Demographic, surgical and electrolyte data were recorded from the electronic database.

Results

From 2000 to 2016, pediatric thyroid surgery at our institution was performed on 33 patients without a consistent approach or standard electrolyte management. A protocol for perioperative management of these patients was introduced in 2017, and applied to 13 patients. In 2019, the protocol was assessed and updated following a case of symptomatic hypocalcemia. From 2000 to 2016, 47 pediatric patients in all underwent thyroid surgery. We registered eight asymptomatic hypocalcemias. One child developed symptomatic hypocalcemia. Two patients have permanent hypoparathyroidism.

Discussion

Our incidence of general complications following thyroidectomy was low; hypocalcemia was the most prevalent. All the cases of hypocalcemia submitted to the protocol were identified early by iPTH measurements. Intraoperative iPTH levels and percentage drop from baseline could help stratify patients according to their risk of hypocalcemia. High risk patients require immediate postoperative supplementation, including calcitriol and calcium carbonate.

Approach to the Patient: Management and the Long-term Consequences of Graves' Disease in Children

In children, Graves' disease (GD) is the most common cause of hyperthyroidism. Most pediatric patients with GD will not go into lasting remission, even following many years of antidrug therapy. Thus, most pediatric patients will require radioactive iodine (RAI) or surgery. When antithyroid drugs are used, methimazole is the drug of choice. When methimazole is used in children, up to 20% will have minor adverse reactions and serious adverse events occur in up to 1%. RAI is an effective form of therapy when the thyroid size is less than 80 g. Because of concerns of whole-body radiation exposure, it is recommended that RAI be avoided in children under 5 years of age, and dosages less than 10 mCi be used between 5 and 10 years of age. Surgery is an effective treatment in children if performed by a high-volume thyroid surgeon. Because of the scarcity of high-volume pediatric thyroid surgeons, a multidisciplinary approach using pediatric surgeons and endocrine surgeons can be considered. Whereas there is a trend toward long-term antithyroid drug therapy in adults, for several reasons, this approach may not be practical for children. Determining the optimal treatment for the pediatric patient with GD, requires consideration of the risks and benefits relating to age and likelihood of remission.

Incidental Parathyroidectomy Among Pediatric Patients Undergoing Thyroid Surgery

OBJECTIVE

To evaluate rates of incidental parathyroidectomy(IP) and to determine risk factors among children undergoing thyroid surgery.

STUDY DESIGN

Retrospective case-control study.

METHODS

Pediatric patients undergoing thyroidectomy with or without neck dissection were included in this retrospective cohort study over a 20 year period. Demographics, clinical features, and surgical outcomes were evaluated. The primary outcome was the presence of parathyroid tissue in the surgical specimen.

RESULTS

Two hundred and eighty-six patients were included (100 cases with ≥1 parathyroid gland found in the pathology specimen and 186 controls). The most common surgical indication was cancer (49%), followed by benign nodule (25%). Hemithyroidectomy was performed in 119 (42%) patients, total thyroidectomy in 138 (48%), and completion in 29 (10%). Central neck dissection (CND) and lateral neck dissection were performed in 41% and 13%, respectively. 27 (9%) patients had parathyroid reimplantation. On univariable analysis, diagnosis, adenopathy on preoperative ultrasound, extent of thyroidectomy, neck dissection, and parathyroid reimplantation were significant predictors of IP. On multivariate analysis, CND > 5 nodes were the sole predictor of IP. Patients with IP were more likely to require postoperative calcium/vitamin D supplementation compared to those without (44% vs. 16%; P < .001).

CONCLUSIONS

Incidental parathyroidectomy during pediatric thyroidectomy is relatively common. CND was independently predictive of IP. There were increased rates of postoperative hypocalcemia when 1 or more parathyroid gland was identified in the specimen. Reimplantation of 1 parathyroid gland was predictive of another gland in the specimen. Anticipating outcomes may help optimize patient care by allowing for early supplementation, frequent monitoring, and consideration of ancillary monitoring modalities in high-risk procedures.

LEVEL OF EVIDENCE

Level 4 Laryngoscope, 132:2262-2269, 2022.

The Effect of Pre-Thyroidectomy Calcitriol Prophylaxis on Post-Thyroidectomy Hypocalcaemia in Children

INTRODUCTION

Transient or persistent hypoparathyroidism is one of the most well-known complications of total thyroidectomy and may lead to symptomatic hypocalcaemia. In children, treatment of post-thyroidectomy hypocalcaemia usually consists of postoperative calcium and/or vitamin D supplementation. In 2013, we implemented prophylactic pre-thyroidectomy calcitriol supplementation for all children undergoing total thyroidectomy at the Amsterdam UMC. The objective of this study was to evaluate the efficacy of this prophylactic calcitriol supplementation in preventing post-thyroidectomy hypocalcaemia in children.

METHODS

In a retrospective case study, we included all children (age <18 years), who underwent a total or completion thyroidectomy in the Amsterdam UMC, between 2000 and 2020. Patients were divided into two groups, patients with preoperative calcitriol supplementation and those without (controls). Hypocalcaemia was defined as total serum calcium concentration of <2.0 mmol/L. The primary outcome measure was the occurrence of hypocalcaemia in the first 72 h after surgery. Secondary outcome measures were occurrence of symptomatic hypocalcaemia, need for medical intervention within the first 72 h after surgery, and length of hospitalization.

RESULTS

A total of 51 patients were included; 26 with calcitriol prophylaxis and 25 controls. There was no significant difference in occurrence of hypocalcaemia (17/26 prophylaxis group; 18/25 control group). Median postoperative calcium concentrations in the first 72 h were significantly higher in the group with prophylaxis at 30-35 h (2.26 vs. 2.01 mmol/L) and 36-41 h (2.17 vs. 1.92 mmol/L). Occurrence of symptomatic hypocalcaemia, need for medical intervention, and length of hospitalization were not significantly different between the groups.

CONCLUSION

Calcitriol prophylaxis resulted in somewhat higher postoperative calcium concentrations but did not reduce the occurrence of hypocalcaemia or affect clinical outcome measures such as occurrence of symptomatic hypocalcaemia and length of postoperative hospitalization.

Long-term Follow-up of a Toddler with Papillary Thyroid Carcinoma: A Case Report with a Literature Review of Patients Under 5 Years of Age

Papillary thyroid cancer (PTC) is extremely rare in children. Herein, we present a case diagnosed with PTC at 15 months of age. We conducted a literature review of the published cases with PTC under five years of age. A 1.25-year-old male patient had initially presented with a complaint of progressively enlarging cervical mass that appeared four months earlier. On physical examination, a mass located in the anterior cervical region with the largest measurements of around 3x3 cm was detected. Cervical and thyroid ultrasonography showed a 50x27 mm solid mass in the right lateral neck. Excisional biopsy revealed a follicular variant of PTC with capsular invasion. Subsequently, he underwent a complementary total thyroidectomy. He was diagnosed with intermediate-risk (T3N0M0) PTC. He developed permanent hypoparathyroidism. In the first year of the operation, he was treated with radioiodine ablation (RAI) since basal and stimulated thyroglobulin (Tg) levels tended to increase. Whole-body scintigraphy was normal in the first year of RAI ablation. On levothyroxine sodium (LT4) treatment, levels of thyroid stimulating hormone (TSH) and Tg were adequately suppressed. He is now 8.5-years-old and disease-free on LT4 replacement therapy for seven years and three months. Pediatric PTC has different biological behavior and an excellent prognosis compared to adults. The optimal treatment strategy for pediatric TC is total thyroidectomy, followed by RAI ablation. Post-operative management should include regular follow-up, TSH suppression by adequate LT4 therapy, serial Tg evaluation, and radioiodine scanning when indicated.

Risk factors for the development of hypocalcemia in pediatric patients after total thyroidectomy - A systematic review

OBJECTIVES

Post-thyroidectomy hypocalcemia is a common complication that causes increased morbidity. This review aims to identify the factors that predict occurrence of hypocalcemia after total thyroidectomy in children and adolescents.

METHODS

Comprehensive searches of English language pediatric (≤18 years of age) articles were performed in Medline, CINAHL, EMBASE, Web of Science and the Cochrane Library. Studies published between January 1, 1970 to August 20, 2020 regarding risk factors and strategies to prevent hypocalcemia were included if the study: 1. included only pediatric patients who were ≤18 years of age, 2. included only patients who had total, subtotal or completion thyroidectomy, 3. defined hypocalcemia as serum total calcium of <2.0 mmol/L (8 mg/dL) or ionized calcium of <1.0 mmol/L. The quality of included papers was assessed using the Newcastle-Ottawa scale. Results of all included studies were summarised. Meta-analyses were performed if appropriate.

RESULTS

Five studies with a total of 477 patients between 0 and 18 years, who had total/subtotal/completion thyroidectomy, were included. Overall rates of transient hypocalcemia were higher than permanent hypocalcemia (transient n = 104, 22%; permanent n = 48, 10%). Two studies found intraoperative parathyroid hormone (PTH) useful in predicting hypocalcemia. While two single institution cohort studies reported that neck dissection, male sex and a lower Parathyroid Gland Remaining In Situ score were associated with hypocalcemia, two other studies, including one population-based cohort study, reported that age at surgery, patient sex, hospital volume, type of thyroid disease, number of identified parathyroid glands, parathyroid auto-transplantation, operation time, thyroid specimen weight, and lymph node dissection were not risk factors for hypocalcemia.

CONCLUSION

Intraoperative PTH may be useful in predicting hypocalcemia in children after total thyroidectomy. No consistent clinical risk factors or preventative methods were identified in the pediatric literature. High-quality pediatric research is urgently required to address this knowledge gap.

Hypocalcemia prevention and management after thyroidectomy in children: A systematic review

INTRODUCTION

Hypocalcemia is the most common complication following thyroidectomy in children. Guidelines to manage post-thyroidectomy hypocalcemia are available for adults, but not children. The objective of this review was to identify practices related to hypocalcemia prevention and management in pediatric patients.

METHODS

We identified studies examining the prevention and management of hypocalcemia in pediatric patients post-thyroidectomy within PubMed, EMBASE, Web of Science and Cochrane databases. Three independent reviewers screened citations and reviewed full-text papers.

RESULTS

A total of 15 studies were included, representing 1552 patients. The overall study quality was weak with lack of randomization and inconsistent outcome reporting. The pooled incidence of hypocalcemia from the 15 studies was 35.5% for transient hypocalcemia and 4.2% for permanent hypocalcemia. All studies discussed post-operative hypocalcemia treatment, with most patients requiring admission for intra-venous calcium therapy. One study described a protocol discharging asymptomatic patients on calcitriol and calcium. Three studies discussed preoperative calcium supplementation in patients at risk of hypocalcemia. No studies examined routine use of calcium and/or vitamin D supplementation to prevent post-operative hypocalcemia.

CONCLUSION

A significant number of children undergoing thyroidectomy develop hypocalcemia. Despite this high incidence, our systematic review demonstrates significant practice variation surrounding post-thyroidectomy hypocalcemia prevention and management in children.

LEVEL OF EVIDENCE

III (systematic review of studies of which some were case-control studies (III) and some were case series (IV)).

Intraoperative parathyroid hormone measurement facilitates outpatient thyroidectomy in children

INTRODUCTION

We hypothesize that intraoperative parathyroid hormone (ioPTH) measurement after a total thyroidectomy predicts children at risk for hypoparathyroidism and allow for outpatient procedure.

METHODS

Between 2015 and 2019, we reviewed all patients under the age of 21 undergoing a thyroidectomy (total or lobectomy). Based on the ioPTH concentration, the patients were treated by the following protocol: a) PTH ≥20 pg/mL: no treatment; b) PTH = 10-19 pg/mL: 1000 mg calcium orally TID; c) PTH = 5-9 pg/mL: calcitriol 250 μg orally BID plus 1000 mg calcium orally TID; or d) PTH <5 pg/mL calcitriol 500 μg orally BID plus 1000 mg calcium orally TID.

RESULTS

Fifty-two patients were included with a median age of 16 (range 6-21 years). Thirty-two patients (62%) had normal PTH (≥10 pg/mL) while 20 (38%) had low PTH levels (<10 pg/mL). Of those patients with low PTH, 60% had normalization of levels within 2 weeks of surgery.

CONCLUSIONS

Thyroid surgery in children can be performed as an outpatient procedure. The ioPTH measurements and a protocol to treat patients with low PTH assists in safe discharge.

Management of Differentiated Thyroid Carcinoma in Pediatric Patients

Differentiated thyroid carcinomas are rare in young children but represent almost 10% of all malignancies diagnosed in older adolescents. Differentiated thyroid carcinoma in children is more likely to demonstrate nodal involvement and is associated with higher recurrence rates than seen in adults. Decisions regarding extent of surgical resection are based on clinical and radiologic features, cytology, and risk assessment. Total thyroidectomy and compartment-based resection of involved lymph node basins form the cornerstone of treatment. The use of molecular genetics to inform treatment strategies and the use of targeted therapies to unresectable progressive disease is evolving.

Consensus statement by the American Association of Clinical Endocrinology (AACE) and the American Head and Neck Society Endocrine Surgery Section (AHNS-ES) on Pediatric Benign and Malignant Thyroid Surgery

OBJECTIVES

To provide a clinical disease state review of recent relevant literature and to generate expert consensus statements regarding the breadth of pediatric thyroid cancer diagnosis and care, with an emphasis on thyroid surgery. To generate expert statements to educate pediatric practitioners on the state-of-the-art practices and the value of surgical experience in the management of this unusual and challenging disease in children.

METHODS

A literature search was conducted and statements were constructed and subjected to a modified Delphi process to measure the consensus of the expert author panel. The wording of statements, voting tabulation, and statistical analysis were overseen by a Delphi expert (J.J.S.).

RESULTS

Twenty-five consensus statements were created and subjected to a modified Delphi analysis to measure the strength of consensus of the expert author panel. All statements reached a level of consensus, and the majority of statements reached the highest level of consensus.

CONCLUSION

Pediatric thyroid cancer has many unique nuances, such as bulky cervical adenopathy on presentation, an increased incidence of diffuse sclerosing variant, and a longer potential lifespan to endure potential complications from treatment. Complications can be a burden to parents and patients alike. We suggest that optimal outcomes and decreased morbidity will come from the use of advanced imaging, diagnostic testing, and neural monitoring of patients treated at high-volume centers by high-volume surgeons.

Consensus Statement by the American Association of Clinical Endocrinology (AACE) and the American Head and Neck Society Endocrine Surgery Section (AHNS) on Pediatric Benign and Malignant Thyroid Surgery

OBJECTIVES

To provide a clinical disease state review of recent relevant literature and to generate expert consensus statements regarding the breadth of pediatric thyroid cancer diagnosis and care, with an emphasis on thyroid surgery. To generate expert statements to educate pediatric practitioners on the state-of-the-art practices and the value of surgical experience in the management of this unusual and challenging disease in children.

METHODS

A literature search was conducted and statements were constructed and subjected to a modified Delphi process to measure the consensus of the expert author panel. The wording of statements, voting tabulation, and statistical analysis were overseen by a Delphi expert (J.J.S.).

RESULTS

Twenty-five consensus statements were created and subjected to a modified Delphi analysis to measure the strength of consensus of the expert author panel. All statements reached a level of consensus, and the majority of statements reached the highest level of consensus.

CONCLUSION

Pediatric thyroid cancer has many unique nuances, such as bulky cervical adenopathy on presentation, an increased incidence of diffuse sclerosing variant, and a longer potential lifespan to endure potential complications from treatment. Complications can be a burden to parents and patients alike. We suggest that optimal outcomes and decreased morbidity will come from the use of advanced imaging, diagnostic testing, and neural monitoring of patients treated at high-volume centers by high-volume surgeons.

Pediatric Thyroid Cancer: Genetics, Therapeutics and Outcome

An increasing number of children are diagnosed with thyroid cancer. Most patients do not have an identifiable cause; however, tumor predisposition syndromes may be associated with development of both differentiated and medullary thyroid cancer. With an excellent prognosis for most patients, the goal of therapy is to optimize outcome and reduce complications. The increased knowledge of the oncogenic drivers provides opportunities to improve the accuracy of diagnosis, stratify surgery, and select systemic therapy that may be considered for neoadjuvant and adjuvant treatment. Treatment complications can be reduced by referral to regional, high-volume pediatric thyroid centers.

Pediatric differentiated thyroid carcinoma: An update from the APSA Cancer Committee

BACKGROUND

Differentiated thyroid carcinomas (DTCs) are rare in young children but represent almost 10% of all malignancies diagnosed in older adolescents.

METHODS

This article reviews the recent literature describing surgical therapeutic approaches to pediatric DTC, associated complications, and long-term recurrence and survival outcomes.

RESULTS

Similar to adult thyroid cancers, pediatric DTCs are more common in females and are associated with thyroid nodules, family history of thyroid cancer, radiation exposure, iodine deficiency, autoimmune thyroid disease, and genetic syndromes. Management of thyroid cancers in children involves ultrasound imaging, fine needle aspiration, and surgical resection with treatment decisions based on clinical and radiological features, cytology and risk assessment.

CONCLUSIONS

Total thyroidectomy and compartment based resection of clinically involved lymph node basins form the cornerstone of treatment of DTC. There is an evolving literature regarding the use of molecular genetics to inform treatment strategies and the use of targeted therapies to treat iodine refractory and surgically unresectable progressive disease.

TYPE OF STUDY

Summary review.

LEVEL OF EVIDENCE

This is a review article of previously published Level 1-5 articles that includes expert opinion (Level 5).

Papillary and Follicular Thyroid Cancer in children and adolescents: Current approach and future directions

An increasing number of children are diagnosed with differentiated thyroid cancer. With an excellent prognosis for the majority of pediatric patients, the goal of therapy is to optimize outcome while reducing complications. Increased knowledge of the somatic, oncogenic driver mutations provides opportunities to improve the accuracy of diagnosis, to stratify surgery, and to treat patients with morbidly invasive or refractory disease. Treatment complications can be reduced by referral to regional, high-volume pediatric thyroid centers.