Hypocalcemia following thyroid surgery: incidence and risk factors. A longitudinal multicenter study comprising 2,631 patients

Impact of parathyroid gland classification on hypoparathyroidism following total thyroidectomy with central neck dissection for differentiated thyroid cancer

OBJECTIVE

To assess the impact of parathyroid gland (PG) classification on hypoparathyroidism incidence following total thyroidectomy (TT) with central neck dissection (CND) in patients with differentiated thyroid carcinoma (DTC).

METHODS

In this prospective cohort study, adult patients with DTC who underwent TT with CND between 2021 and 2023 were enrolled, with a maximum follow-up duration of 32 months. A simplified PG classification system was employed, categorizing glands into four distinct types: tightly connected, loosely connected, non-connected, and thymic. The intraoperative frequency of each PG type was recorded based on this classification. Parathyroid hormone (PTH) levels were routinely tested 1 day, 1 month, 6 months and 1 year after surgery. The association between PG classification and the incidence of postoperative hypoparathyroidism was then systematically analysed.

RESULTS

Among 135 patients with DTC (mean age: 48.50 ± 10.52 years; 101 women), 62 patients (45.93%) developed hypoparathyroidism on postoperative day 1 (POD1), while 14 patients (10.37%) experienced hypoparathyroidism on postoperative month 1 (POM1). All patients exhibited PTH normalization within six months, with no permanent hypoparathyroidism cases. A total of 532 PGs were identified: 264 (49.62%) were tightly connected, 150 (28.20%) loosely connected, 95 (17.86%) non-connected, and 23 (4.32%) thymic. The highest prevalence of hypoparathyroidism on POD1 was observed in patients with four tightly connected PGs (p < 0.001). Patients with four tightly connected PGs had a significantly greater incidence of hypoparathyroidism than those with none (p = 0.024). Regression analysis revealed that each additional tightly connected PG increased the risk of hypoparathyroidism by 1.38 times (p = 0.019). Tightly connected PGs demonstrated predictive value for POD1 hypoparathyroidism (AUC = 0.604, cut-off: two tightly connected glands). In contrast, thymic PGs did not provide a protective effect.

CONCLUSION

PG classification may serve as a valuable tool for surgeons in intraoperative parathyroid preservation and the prediction of postoperative hypoparathyroidism in patients with DTC. Notably, DTC patients with more than two tightly connected PGs are at an elevated risk of developing temporary hypoparathyroidism, emphasizing the importance of meticulous parathyroid preservation during surgical procedures.

Prevalence and Predictors of Postoperative Hypoparathyroidism: A Multicenter Observational Study

Background/Objectives: Hypoparathyroidism (HPT) is a common complication following thyroid surgery with an incidence reaching up to 29%, potentially resulting in significant long-term morbidity. To improve its early identification and patient outcomes, we investigated the prevalence and predictors of postoperative HPT. Methods: This retrospective, multicenter observational study included patients who underwent thyroid surgery from 2016 to 2022 in four centers located in Saudi Arabia's Eastern Province. We analyzed demographic data, underlying thyroid or parathyroid conditions, surgical indications, types of procedures, pathology results, and preoperative corrected calcium and vitamin D levels, along with postoperative corrected calcium and parathyroid hormone (PTH) levels. For data analysis, IBM Statistical Package for the Social Sciences (SPSS) Statistics 22 was used, with categorical variables presented as frequencies/percentages and non-normal continuous variables as the median/first quartile (Q1) and third quartile (Q3). Associations were tested with chi-square/Fisher exact tests, medians with Mann-Whitney U-tests, and odds ratios (ORs) with 95% confidence intervals (CIs) via multivariate analysis with statistical significance set at p < 0.05. Results: A total of 679 cases were included. The median age of patients was 43 years (with 48.9% of them aged 41-60 years), and 82% were female. HPT occurred in 228 cases (35.3%), with 115 (81.0%) experiencing transient HPT and 27 (19.0%) permanent HPT. Multivariate analysis identified total thyroidectomy (OR 2.7, p = 0.005), completion thyroidectomy (OR 8.4, p = 0.004), and low immediate postoperative PTH level (OR 3.1, p < 0.001) as independent predictors of HPT. Central lymph node dissection (CLND; OR 4.03, p = 0.004) and low postoperative PTH level (OR 2.56, p = 0.049) were significant predictors of permanent HPT. Conclusions: Key predictors of HPT include surgical extent and low postoperative PTH level, while CLND and low postoperative PTH level are the strongest predictors of permanent HPT. Careful assessment of these risks when determining the extent of surgery and avoiding unnecessary aggressive procedures can help to minimize the occurrence of HPT. Measuring the PTH level immediately after surgery may aid in identifying high-risk patients for early intervention and appropriate follow-up.

Pilot study of ultrasound-guided microwave ablation for inactivating excess remnant thyroid after surgery in patients with differentiated thyroid cancer

OBJECTIVES

To evaluate the safety and efficacy of ultrasound (US)-guided microwave ablation (MWA) for inactivating excess remnant thyroid (RT) after surgery in patients with differentiated thyroid cancer (DTC).

METHODS

This study was registered in the Chinese Clinical Trial Registry under the identifier ChiCTR2200063200 on September 1, 2022. This study enrolled consecutive postsurgery DTC patients who were scheduled for radioactive iodine ablation (RAI) therapy. These patients exhibited excess RT, which was removed via MWA. Changes in RT volume/weight before and after MWA, as well as alterations in laboratory parameters, were assessed. Complications arising from MWA were documented and monitored.

RESULTS

Twenty-three patients participated in the study. Following US-guided MWA, there was a statistically significant decrease in the volume/weight of RT, from [2.90 (1.78, 4.28)] mL/[2.66 (1.63, 3.92] g to (0.93 ± 0.43) mL/(0.83 ± 0.40) g (P < 0.001). Nineteen patients had an RT weight < 1 g post-MWA. An observed threshold effect between TSH levels and post-MWA follow-up time revealed an inflection point at 17.0 days, with TSH levels increasing by 2.5 mU/L per day from 0 to 17.0 days (P < 0.001), peaking above 30 mU/L on day 17.0. The TSH level subsequently decreased by 1.6 mU/L per day (P = 0.028) after 17.0 days. No serious complications were noted.

CONCLUSIONS

US-guided MWA is a relatively safe and effective method for inactivating excess RT after surgery and represents a potentially innovative minimally invasive approach. The relationship between TSH and follow-up time after MWA for inactivating excess RT reveals a threshold effect, aiding in determining the optimal timing for RAI therapy post-MWA, yet its universal applicability necessitates additional investigation.

Indocyanine green angiography to evaluate immediate hypoparathyroidism after thyroid cancer surgery

INTRODUCTION

Indocyanine green (ICG) fluorescence angiography has been introduced to assess parathyroid perfusion intraoperatively. This study aimed to evaluate whether the number of well-vascularized parathyroid glands identified using ICG fluorescence could predict the maintenance of adequate parathyroid hormone (PTH) levels in the immediate postoperative period.

MATERIALS AND METHODS

A retrospective study was conducted on 150 consecutive patients who underwent total thyroidectomy for papillary thyroid cancer between March 2021 and December 2023. Parathyroid perfusion was assessed using ICG fluorescence angiography, and glands were classified on a scale from 0 (no vascularization) to 2 (good vascularization). PTH levels were measured 1 h postoperatively, and biochemical hypoparathyroidism was defined as PTH < 15 pg/dL. Statistical analyses were performed using Fisher's exact test and Chi-square test, with p < 0.05 considered significant.

RESULTS

Transient biochemical hypoparathyroidism occurred in 34.7% of patients. Among patients with two or more well-vascularized parathyroid glands (score 2), 70.2% did not experience a decrease in parathyroid hormone levels below 15 pg/mL (NPV 70.2%, 95% CI: 62.4-78.1%). However, 29.8% of patients with two or more well-vascularized glands still developed hypoparathyroidism, highlighting the limitations of using this metric alone to predict postoperative outcomes. The overall accuracy for predicting hypoparathyroidism was 70% (95% CI: 62.7-77.3%). No patient developed permanent hypoparathyroidism.

CONCLUSION

ICG fluorescence angiography is a reliable tool for assessing parathyroid gland perfusion during thyroidectomy. However, the identification of two or more well-vascularized parathyroid glands does not completely exclude the risk of transient hypoparathyroidism, indicating that additional factors must be considered in predicting postoperative outcomes.

Optimal cutoff values of intraoperative parathyroid hormone for predicting early and permanent hypoparathyroidism after total thyroidectomy

PURPOSE

Measurement of intraoperative intact parathyroid hormone (ioPTH) levels is a reliable predictor of postsurgical hypocalcemia. We assessed the optimal cutoff values of ioPTH decline for predicting postoperative early and permanent hypoparathyroidism.

METHODS

This was a retrospective study of a prospectively maintained database of patients undergoing thyroid surgery in a tertiary care hospital in L'Hospitalet de Llobregat (Barcelona, Spain). All consecutive patients undergoing total thyroidectomy with or without central neck dissection between January 2005 and May 2021 were analyzed. The best cutoff value of the decrease of ioPTH level between PTH assessed after induction of anesthesia and at 10 min after completion of surgery for predicting hypocalcemia was evaluated.

RESULTS

We included 742 patients (mean age 52 years) (thyroid cancer 48%, neck dissection 42%) undergoing total thyroidectomy. Postoperative hypocalcemia was diagnosed in 383 (51.6%) patients, which was transient in 296 (39.9%) and permanent in 87 (11.7%). The optimal cutoff value for predicting transient hypocalcemia was a decline of ioPTH level of ≤ 62.5% (overall efficacy 87%), but calcium supplementation may be indicated in high-risk cutoff values of ≥ 79.9%. In patients with an ioPTH decline ≤ 39%, the probability of postoperative hypocalcemia is extremely unlikely. Patients with declines > 93.7% should be followed very closely since they are high-risk for developing permanent hypoparathyroidism.

CONCLUSION

The decline of ioPTH, measured as the difference between ioPTH before thyroidectomy and after completion of the surgical procedure is a reliable indicator of the likelihood of postoperative transient hypocalcemia, with optimal cutoff value of 62.5%.

Hypercalcemia Following Adrenalectomy for Cushing Syndrome in a Patient with Post-Surgical Hypoparathyroidism

Background: Hypercalcemia is a frequently encountered laboratory finding in endocrinology, warranting accurate clinical and laboratory evaluation to identify its cause. While primary hyperparathyroidism and malignancies represent the most common causes, many other etiologies have been described, including some reports of hypercalcemia secondary to adrenal insufficiency. On the contrary, hypoparathyroidism is a relatively common cause of hypocalcemia, often arising as a complication of thyroid surgery. In real-world clinical practice, however, many challenges come into play, and a comprehensive approach may not be enough to establish a diagnosis. Case presentation: we describe a peculiar case of severe hypercalcemia occurring in a 47-year-old woman with a previous history of post-surgical permanent hypoparathyroidism treated with calcitriol (0.5 µg bid) and calcium carbonate (1 g qd), which persisted after withdrawal of these drugs. During her follow-up, an ACTH-independent Cushing syndrome was diagnosed, leading to a unilateral right adrenalectomy. In the two months following surgery, she was admitted to the emergency ward on three occasions because of severe, persistent, idiopathic hypercalcemia. On each occasion, parathyroid hormone levels were confirmed to be undetectable, with low vitamin D levels. Common and rare causes of hypercalcemia were excluded, and the persistence of severely elevated calcium levels led to the empirical use of intravenous clodronate, achieving remission of both hypercalcemia and, unexpectedly, hypoparathyroidism. After 8 months, due to borderline-reduced calcium, calcitriol at 0.5 µg qd was restarted. After 18 months of follow-up, the patient is well and normocalcemic, with low-dose calcitriol. Notably, the patient had no acute adrenal insufficiency, distinguishing this case from other post-adrenalectomy hypercalcemia reports. Conclusions: the history of hypoparathyroidism makes this case even more unusual, and it encourages careful follow-up of hypoparathyroid patients with Cushing syndrome. Ongoing observation, as well as new research on the physiopathology of cortisol and calcium metabolism, are needed to clarify the pathogenesis of this case.

State of the art of neuromonitoring in thyroid surgery

Thyroidectomy is a common procedure in endocrine surgery, frequently performed to treat benign and malignant thyroid conditions. Recurrent laryngeal nerve (RLN) injury, a major complication, underscores the necessity for meticulous nerve dissection during surgery. Intraoperative neuromonitoring (IONM) has emerged as a valuable adjunct to visual identification in RLN preservation. This review synthesizes current literature on IONM in thyroid surgery, emphasizing its role in enhancing RLN integrity assessment and reducing surgical complications such as vocal cord paralysis. IONM techniques include intermittent and continuous monitoring, each offering distinct benefits in nerve function evaluation. While debate persists regarding IONM's efficacy in mitigating unilateral RLN injuries, protocols integrating IONM data have significantly reduced the incidence of bilateral RLN injury, exemplifying advancements in surgical safety. Challenges remain, including variability in study outcomes and the optimal timing of IONM application.

The predictive role of intraoperative parathyroid hormone measurement on postoperative parathyroid function in patients undergoing total thyroidectomy

Hypocalcemia is a common complication of thyroidectomy, particularly total thyroidectomy. The higher incidence of hypocalcemia following total thyroidectomy is primarily due to inadvertent damage to the parathyroid glands during surgery. This study aims to investigate the predictive value of intraoperative parathyroid hormone (IOPTH) in determining hypocalcemia during hospitalization and the recovery of parathyroid function after total thyroidectomy, as well as the factors that may influence IOPTH. In this retrospective study, we analyzed a cohort of 164 patients who underwent total thyroidectomy at our institution between 2018 and 2019. IOPTH was measured either 15 min after bilateral thyroidectomy combined with area VI lymph node dissection, or 15 min after bilateral thyroidectomy alone. We plotted ROC curves for IOPTH and ΔPTH% in relation to hypocalcemia during hospitalization and recovery of parathyroid function. Additionally, we explored risk factors for the development of hypocalcemia during hospitalization and factors that may influence IOPTH. IOPTH and ΔPTH% demonstrated good specificity and sensitivity for predicting hypocalcemia during hospitalization and for assessing recovery of parathyroid function. Lower preoperative PTH levels, chronic lymphocytic thyroiditis, and intraoperative parathyroid auto-transplantation were identified as risk factors for IOPTH < 15 pg/mL. IOPTH and ΔPTH% are predictive of hypocalcemia during the postoperative hospital stay and recovery of parathyroid function. Patients with chronic lymphocytic thyroiditis, intraoperative parathyroid auto-transplantation, and low preoperative PTH levels should be closely monitored for the recovery of parathyroid function after surgery.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Risk Factors for Transient Hypoparathyroidism after Total Thyroidectomy: Insights from a Cohort Analysis

Background: Transient hypoparathyroidism (TH) is the main post-thyroidectomy complication, significantly impacting surgical outcomes, hospitalization length, and perceived perceived quality of life understood as mental and physical well-being. This study aims to identify possible associated risk factors. Methods: We analyzed 238 thyroidectomies (2020-2022), excluding instances of partial surgery, primary hyperparathyroidism, neck irradiation history, and renal failure. The variables considered were as follows: demographics, histology, autoimmunity, thyroid function, pre- and postoperative Vitamin D levels (where available), type of surgery, number of incidentally removed parathyroid glands (IRP), and surgeons' experience (>1000 thyroidectomies, <500, in training). Univariate analysis applied: χ2, Fisher's exact test for categorical variables, and Student's t-test for continuous variables. Subsequently, logistic multivariate analysis with stepwise selection was performed. Results: Univariate analysis did not yield statistically significant results for the considered variables. The 'No Complications' group displayed a mean age of 55 years, whereas the TH group showed a mean age of 51 (p-value = 0.055). We considered this result to be marginally significant. Subsequently, we constructed a multivariate logistic model. This model (AIC = 245.02) indicated that the absence of incidental parathyroidectomy was associated with the age class >55 years, presenting an odds ratio (OR) of 9.015 (p-value < 0.05). Simultaneously, the age class >55 years exhibited protective effects against TH, demonstrating an OR of 0.085 (p-value < 0.01). Similarly, the absence of incidental parathyroidectomy was found to be protective against TH, with an OR of 0.208 (p-value < 0.01). Conclusions: Multivariate analysis highlighted that having "No IRP" was protective against TH, while younger age was a risk factor. Surgeon experience does not seem to correlate with IRP or outcomes, assuming there is adequate tutoring and a case volume close to 500 to ensure good results. The effect of reimplantation has not been evident in transient hypoparathyroidism.

Mapping the lymph node metastasis landscape: A bibliometric Odyssey of papillary thyroid carcinoma publications (2012-2022)

Objective

Lymph node metastasis in papillary thyroid carcinoma (PTC) has become an area of great interest in the study of thyroid diseases. The aim of this study was to elucidate the research trends and impact of lymph node metastasis of PTC in the study of thyroid diseases through a comprehensive bibliometric analysis.

Methods

We conducted an extensive bibliometric review of the literature on lymph node metastasis in PTC using the Web of Science Core Database (WOSCC), which included approximately 3292 publications from 2012 to 2022. Data analysis and visualization were performed, using advanced bibliometric tools including VOSviewer, CiteSpace, and bibliometrix R software packages.

Results

A total of 3292 publications from 81 one countries were identified. The analysis showed a pattern of growth in the number of publications per year from 2012 to 2022, with China having the highest number of papers. Outstanding contributions were made by China, Korea, USA, Italy and Japan, with Thyroid being the most important journal. The author who published the most papers was Jingqiang Zhu. The institutions that published the most papers were Shanghai Jiao Tong University and Yonsei University. The analysis found that prognosis, recurrence, and ultrasound were the keywords with the highest frequency of occurrence in addition to those related to the title of this article.

Conclusion

Our bibliometric analysis outlines the current state of research on lymph node metastasis in PTC, highlighting significant contributions, trends, and future research directions.

Comparison of indocyanine green angiography vs intraoperative parathyroid hormone in early prediction of risk of post-thyroidectomy hypocalcemia: a prospective cohort study

Introduction

Indocyanine green (ICG) angiography is the 'real-time intraoperative imaging' technique used to reduce the chances of hypoparathyroidism in post-thyroidectomy patients. In our study, the authors predicted the risk of early post-thyroidectomy hypocalcemia by intraoperative evaluation of parathyroid gland perfusion by ICG angiography.

Materials and methods

In patients who underwent total thyroidectomy, ICG angiography was done using the SPY PHI imaging system (Stryker). Post-thyroid specimen removal, scoring of parathyroids was done in spy contrast mode. All 4 or <4 visualized parathyroids were scored for vascularity with the highest score of 8. Serum ionized calcium was done 6 h postsurgery and on the morning and evening of postoperative days 1 and 2. Calcium supplements were given to only those who developed clinical or severe biochemical hypocalcemia.

Results

Out of 60, postoperative hypocalcemia was noted in 41 patients. Total ICG score ≤5 was seen in 34 patients, out of which 28 developed postoperative hypocalcemia showing PPV 82.3% and diagnostic accuracy of 68.3% while iPTH (4.28 pmol/l) showed PPV 76.7 and diagnostic accuracy 70 %. In eight patients, none of the glands was scored as 2 (White) and all these patients developed hypocalcemia requiring calcium infusion.

Conclusion

The absence of visualization of at least 1 well-perfused (score 2) gland on ICG angiography is highly predictive of hypocalcemia and the majority of patients with total ICG score ≤5 developed hypocalcemia in the immediate postoperative period. ICG is a good predictor of the absence of hypoparathyroidism after thyroidectomy and is comparable to iPTH in the prediction of post-thyroidectomy hypocalcemia.

Management of Postthyroidectomy Hypoparathyroidism and Its Effect on Hypocalcemia-Related Complications: A Meta-Analysis

OBJECTIVE

The aim of this Meta-analysis is to evaluate the impact of different treatment strategies for early postoperative hypoparathyroidism on hypocalcemia-related complications and long-term hypoparathyroidism.

DATA SOURCES

Embase.com, MEDLINE, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, and the top 100 references of Google Scholar were searched to September 20, 2022.

REVIEW METHODS

Articles reporting on adult patients who underwent total thyroidectomy which specified a treatment strategy for postthyroidectomy hypoparathyroidism were included. Random effect models were applied to obtain pooled proportions and 95% confidence intervals. Primary outcome was the occurrence of major hypocalcemia-related complications. Secondary outcome was long-term hypoparathyroidism.

RESULTS

Sixty-six studies comprising 67 treatment protocols and 51,096 patients were included in this Meta-analysis. In 8 protocols (3806 patients), routine calcium and/or active vitamin D medication was given to all patients directly after thyroidectomy. In 49 protocols (44,012 patients), calcium and/or active vitamin D medication was only given to patients with biochemically proven postthyroidectomy hypoparathyroidism. In 10 protocols (3278 patients), calcium and/or active vitamin D supplementation was only initiated in case of clinical symptoms of hypocalcemia. No patient had a major complication due to postoperative hypocalcemia. The pooled proportion of long-term hypoparathyroidism was 2.4% (95% confidence interval, 1.9-3.0). There was no significant difference in the incidence of long-term hypoparathyroidism between the 3 supplementation groups.

CONCLUSIONS

All treatment strategies for postoperative hypocalcemia prevent major complications of hypocalcemia. The early postoperative treatment protocol for postthyroidectomy hypoparathyroidism does not seem to influence recovery of parathyroid function in the long term.

Risk factors for postoperative cervical haematoma in patients undergoing thyroidectomy: a retrospective, multicenter, international analysis (REDHOT study)

Background

Postoperative cervical haematoma represents an infrequent but potentially life-threatening complication of thyroidectomy. Since this complication is uncommon, the assessment of risk factors associated with its development is challenging. The main aim of this study was to identify the risk factors for its occurrence.

Methods

Patients undergoing thyroidectomy in seven high-volume thyroid surgery centers in Europe, between January 2020 and December 2022, were retrospectively analysed. Based on the onset of cervical haematoma, two groups were identified: Cervical Haematoma (CH) Group and No Cervical Haematoma (NoCH) Group. Univariate analysis was performed to compare these two groups. Moreover, employing multivariate analysis, all potential independent risk factors for the development of this complication were assessed.

Results

Eight thousand eight hundred and thirty-nine patients were enrolled: 8,561 were included in NoCH Group and 278 in CH Group. Surgical revision of haemostasis was performed in 70 (25.18%) patients. The overall incidence of postoperative cervical haematoma was 3.15% (0.79% for cervical haematomas requiring surgical revision of haemostasis, and 2.35% for those managed conservatively). The timing of onset of cervical haematomas requiring surgical revision of haemostasis was within six hours after the end of the operation in 52 (74.28%) patients. Readmission was necessary in 3 (1.08%) cases. At multivariate analysis, male sex (P < 0.001), older age (P < 0.001), higher BMI (P = 0.021), unilateral lateral neck dissection (P < 0.001), drain placement (P = 0.007), and shorter operative times (P < 0.001) were found to be independent risk factors for cervical haematoma.

Conclusions

Based on our findings, we believe that patients with the identified risk factors should be closely monitored in the postoperative period, particularly during the first six hours after the operation, and excluded from outpatient surgery.

Parathyroid gland detection using an intraoperative autofluorescence handheld imager - early feasibility study

Introduction

Parathyroid glands may be compromised during thyroid surgery which can lead to hypoparathyroidism and hypocalcemia. Identifying the parathyroid glands relies on the surgeon's experience and the only way to confirm their presence was through tissue biopsy. Near infrared autofluorescence technology offers an opportunity for real-time, non-invasive identification of the parathyroid glands.

Methods

We used a new research prototype (hANDY-I) developed by Optosurgical, LLC. It offers coaxial excitation light and a dual-Red Green Blue/Near Infrared sensor that guides anatomical landmarks and can aid in identification of parathyroid glands by showing a combined autofluorescence and colored image simultaneously.

Results

We tested the imager during 23 thyroid surgery cases, where initial clinical feasibility data showed that out of 75 parathyroid glands inspected, 71 showed strong autofluorescence signal and were correctly identified (95% accuracy) by the imager.

Conclusions

The hANDY-I prototype demonstrated promising results in this feasibility study by aiding in real-time visualization of the parathyroid glands. However, further testing by conducting randomized clinical trials with a bigger sample size is required to study the effect on levels of hypoparathyroidism and hypocalcemia.

Prevention of hypocalcemia and hypoparathyroidism after total thyroidectomy. Recommendations of the Francophone Association of Endocrine Surgery (AFCE) with the French Society of Endocrinology (SFE) and the French Society of Nuclear Medicine (SFMN)

Postoperative hypoparathyroidism, resulting from removal and/or devascularization of one or more parathyroid glands, is a feared complication of total thyroidectomy. Two forms, which are distinguished by their frequency, their time to onset and their duration as well as by their presentation, must be individualized: early postoperative hypocalcemia, often secondary to early hypoparathyroidism is a frequent and often transient situation occurring within the first days after surgery; permanent hypoparathyroidism, which is rarer, manifests when parathyroid function remains impaired for more than six months after surgery. Because of their severity, these conditions must be known and ideally prevented during total thyroidectomy. The objective of this article is to provide surgeons with practical recommendations for the prevention, diagnosis, and treatment of hypoparathyroidism after total thyroidectomy. These recommendations, which are the fruit of a medico-surgical consensus, were developed by the Francophone Association of Endocrine Surgery (AFCE), the French Society of Endocrinology (SFE) and the French Society of Nuclear Medicine and Molecular Imaging. (SFMN). The content, grade and level of evidence for each recommendation was decided after consultation within a panel of experts, based on an analysis of recent literature.

Ultrasound-Guided Radiofrequency Ablation versus Thyroidectomy for the Treatment of Benign Thyroid Nodules in Elderly Patients: A Propensity-Matched Cohort Study

BACKGROUND AND PURPOSE

Ultrasound-guided radiofrequency ablation has been recommended as an alternative to surgery for benign thyroid nodules. However, little is known about the benefit from the application of radiofrequency ablation for benign thyroid nodules in elderly patients. The purpose of this study was to compare the clinical outcomes of radiofrequency ablation versus thyroidectomy for elderly patients with benign thyroid nodules.

MATERIALS AND METHODS

This retrospective study evaluated 230 elderly patients (60 years of age or older) with benign thyroid nodules treated with radiofrequency ablation (R group, n = 49) or thyroidectomy (T group, n = 181). Complications, thyroid function, and treatment variables, including procedural time, estimated blood loss, hospitalization, and cost, were compared after propensity score matching. The volume, volume reduction rate, symptoms, and cosmetic score were also evaluated in the R group.

RESULTS

After 1:1 matching, each group had 49 elderly patients. The rate of overall complications and hypothyroidism was 26.5% and 20.4% in the T group, respectively, but these complications were totally absent from the R group (P < .001, P = .001). Patients in the R group had a significantly shorter procedural time (median, 4.8 versus 95.0 minutes, P < .001) and lower cost (US $1979.02 versus US $2208.80, P = .013) than those treated by thyroidectomy. After radiofrequency ablation, the volume reduction rate was 94.1%, and 12.2% of nodules had completely disappeared. The symptom and cosmetic scores were both significantly reduced at the last follow-up.

CONCLUSIONS

Radiofrequency ablation could be considered as a first-line treatment for elderly patients with benign thyroid nodules.

Risk factors for hypocalcemia and correlation between thyroid volume and incidental parathyroidectomy after total thyroidectomy: single center experience

Aim: We aimed to investigate correlation between the effects of age, sex, disease, pathologic diagnosis, parathyroid autotransplantation, presence of parathyroid in the pathology specimen and clinicopathological variables and thyroid volume, postoperative hypocalcemia after bilateral total thyroidectomy. Material and Method: A retrospective study planned in tertiary university hospital on patients undergone bilateral total thyroidectomy and neck dissection when necessary surgery for thyroid pathologies. Minimum calcium values in the postoperative period were recorded as transient or permanent hypocalcemia. The cases were statistically analyzed for the relationship between the volume of the thyroid gland removed and hypocalcemia. The effects of sex, pathological diagnosis, preoperative hyperthyroidism, anatomical retrosternal extension, number of parathyroid glands seen and preserved intraoperatively, parathyroid gland autoimplantation, parathyroid gland removal in the pathological specimen, nerve monitoring, bilateral total thyroidectomy and central and lateral neck dissection were analyzed for postoperative hypocalcemia. Results: Totally 763 patients were included in the study. The mean age of the patients was 50.6 years (SD:12.8) and the sex of 575 (75.4%) patients was female. Hypocalcemia was more common in women than in men (31% vs 17%; p

Evaluation of an early detection protocol, intensive treatment and control of post-surgical hypoparathyroidism in the first month after total thyroidectomy

BACKGROUND AND OBJECTIVE

Hypoparathyroidism is the most common complication of total thyroidectomy and usually requires monitoring of calcaemia, whereby it is one of the factors that most contributes to hospital stay. The objective of the study is to evaluate the clinical usefulness of the application of our protocol for early detection, intensive treatment and control of hypoparathyroidism in the first month after thyroidectomy.

PATIENTS AND METHOD

Retrospective observational cross-sectional study of 79 patients who underwent total thyroidectomy in whom parathormone (PTH) and calcemia determinations were performed at 6-8 h and 18-24 h post-surgery. When the PTH value was lower than inferior limit of the reference (15 pg/ml), oral treatment was started with 1000 mg of calcium and 0.25 μg of calcitriol every 8 h followed by calcemia controls.

RESULTS

Twenty-six cases (32.9%) of normocalcemic hypoparathyroidism were detected in whom treatment prevented their progression to hypocalcaemia, except for 3 cases that had an episode of mild asymptomatic hypocalcaemia. There were no cases of moderate/severe hypocalcaemia and only one case of asymptomatic mild hypercalcaemia. There were no readmissions due to calcium abnormalities. No case with PTH > 15 pg/ml had hypocalcaemia. The protocol allowed a hospital stay of 24 h. The prevalence of permanent hypoparathyroidism was 5.1%.

CONCLUSIONS

The application of our protocol during the first month after thyroidectomy is very useful because it avoids the appearance of moderate/severe hypocalcaemia and hypercalcaemia, allows a short hospital stay and is associated with a low prevalence of permanent hypoparathyroidism.

Effect of near infrared autofluorescence guided total thyroidectomy on postoperative hypoparathyroidism: a randomized clinical trial

PURPOSE

The purpose of this single-blinded, 2-centre, randomized controlled trial was to test if near-infrared (NIR) autofluorescence image guidance for parathyroid gland (PG) detection during total thyroidectomy can reduce the incidence of hypoparathyroidism in both malignant and benign cases.

METHOD

Patients admitted for primary or completion total thyroidectomy were randomized to either the NIR intervention group or the standard care NONIR (no near infrared) group. The primary endpoint was the rate of hypoparathyroidism at the 3-month follow-up, defined as hypocalcemia and inappropriately low parathyroid hormone levels and/or continuous treatment with active vitamin D. The secondary endpoint was the PG identification rate.

RESULTS

A total of 147 patients were included of whom 73 were allocated to NIR. Primary or completion thyroidectomy was conducted in 84 and 63 cases, respectively. A total of 130 completed 3 months follow-up. Postoperative hypoparathyroidism in the NIR group at 12 h, 1 month and 3 months was, respectively, 31.8, 14.1, 6.5% compared with 35.9, 18.9, 11.8% in the NONIR group (all p > 0.46). In the NIR group, the identification rate of PGs was 69.5% (146 of 210 PGs), and 9% (19 of 210 PGs) were identified only due to additional use of NIR. For 15 out of 69 patients (21.7%) additionally PGs was found.

CONCLUSION

Hypoparathyroidism was nominally less frequent in the NIR group, although not statistically significant. Further studies are needed to confirm if NIR may be a supportive PG identification tool to minimize the number of PG which would have been otherwise missed, especially during more complicated thyroid procedures.

TRIAL REGISTRY

ClinicalTrials.gov: NCT04193332. Registration date: 16.08.2019.

Prevalence and Risk Factors for Hypoparathyroidism Following Total Thyroidectomy in Taif City

Background Postoperative hypoparathyroidism has been investigated in health records and surgical cohorts, but the results have been highly variable and imprecise. It is not clear how often endocrinologists encounter this hormone deficit in clinical practice. Thus, the aim of this study is to determine the incidence of permanent hypoparathyroidism and the factors associated with it in a group of post-thyroidectomy patients followed at three tertiary care institutions in Taif city. Materials and Methods A retrospective cohort analysis was done to examine patients who had a total thyroidectomy in the city of Taif between January 1, 2015, and December 31, 2019. Patients were eligible for the study if they received total thyroidectomy, were above the age of 18 years, had surgical and pathological data available, and had been monitored in the same institution for at least a year after their thyroidectomy. Patients who did not return for follow-up care following surgery were excluded from the study. Results The incidence of hypoparathyroidism was 10.3%, and females had a higher prevalence (12.1%) than males (3.2%). In patients with two and three parathyroid glands, hypoparathyroidism was found to be more prevalent (33.3% and 25.5%) in permanent histological sections. There was no single independent risk factor for hypoparathyroidism according to a logistic regression model. Conclusion The incidence rate of hypoparathyroidism following total thyroidectomy was about 10.3%. There were no independent risk factors identified for hypoparathyroidism after total thyroidectomy. Permanent hypoparathyroidism severely affects the quality of life, and research should be done to prevent its incidence after thyroidectomy.

Epidemiology and Financial Burden of Adult Chronic Hypoparathyroidism

Chronic hypoparathyroidism is characterized by low serum calcium, increased serum phosphorus, and inappropriately low or decreased serum parathyroid hormone. This rare disorder is associated with a variety of complications. The prevalence, incidence, mortality, financial burden, and epidemiology of complications of this disorder are not well understood. This narrative review summarizes current information on the epidemiology and complications of chronic hypoparathyroidism. The reported prevalence of chronic hypoparathyroidism ranges from 6.4-37/100,000, and the incidence is reported to be 0.8-2.3/100,000/year. Mortality is not increased in studies from Denmark or South Korea but was increased in studies from Scotland and Sweden. The financial burden of this disorder is substantial because of increased health care resource utilization in two studies but not well quantitated. Recognized complications include hypercalciuria, nephrocalcinosis, kidney stones, and chronic kidney disease; low bone turnover and possibly upper extremity fractures; cardiac and vascular calcifications; basal ganglia calcifications, cataracts, infections, neuropsychiatric complications, and difficulties with pregnancy. This review concludes that chronic hypoparathyroidism is a rare disorder associated with significant morbidity that may not increase overall mortality but is associated with a substantial financial burden. © 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).

Does the continuation of low-dose acetylsalicylic acid during the perioperative period of thyroidectomy increase the risk of cervical haematoma? A 1-year experience of two Italian centers

BACKGROUND

A growing number of patients taking antiplatelet drugs, mainly low-dose acetylsalicylic acid (ASA) (75-150 mg/day), for primary or secondary prevention of thrombotic events, are encountered in every field of surgery. While the bleeding risk due to the continuation of these medications during the perioperative period has been adequately investigated in several surgical specialties, in thyroid surgery it still needs to be clarified. The main aim of this study was to assess the occurrence of cervical haematoma in patients receiving low-dose acetylsalicylic acid, specifically ASA 100 mg/day, during the perioperative period of thyroidectomy.

METHODS

Patients undergoing thyroidectomy in two high-volume thyroid surgery centers in Italy, between January 2021 and December 2021, were retrospectively analysed. Enrolled patients were divided into two groups: those not taking ASA were included in Group A, while those receiving this drug in Group B. Univariate analysis was performed to compare these two groups. Moreover, multivariate analysis was employed to evaluate the use of low-dose ASA as independent risk factor for cervical haematoma.

RESULTS

A total of 412 patients underwent thyroidectomy during the study period. Among them, 29 (7.04%) were taking ASA. Based on the inclusion criteria, 351 patients were enrolled: 322 were included in Group A and 29 in Group B. In Group A, there were 4 (1.24%) cervical haematomas not requiring surgical revision of haemostasis and 4 (1.24%) cervical haematomas requiring surgical revision of haemostasis. In Group B, there was 1 (3.45%) cervical haematoma requiring surgical revision of haemostasis. At univariate analysis, no statistically significant difference was found between the two groups in terms of occurrence of cervical haematoma, nor of the other early complications of thyroidectomy. At multivariate analysis, the use of low-dose ASA did not prove to be an independent risk factor for cervical haematoma.

CONCLUSIONS

Based on our findings, we believe that in patients receiving this drug, either for primary or secondary prevention of thrombotic events, its discontinuation during the perioperative period of thyroidectomy is not necessary.

Actual prevalence of hypoparathyroidism after total thyroidectomy: a health insurance claims-database study

PURPOSE

Persistent hypoparathyroidism (hypoPT) is a major complication of total thyroidectomy. Nonetheless, previous reports may have underestimated the prevalence of hypoPT due to patient selection bias. We aimed to estimate the actual prevalence of persistent hypoPT after total thyroidectomy and to find predictive factors for postoperative hypoPT.

METHODS

This study retrospectively reviewed data from a health insurance claims-based database provided by the Japan Medical Data Center Co., Ltd. From 2009 to 2019, 2388 patients who underwent total thyroidectomy were identified using the medical procedure codes. Persistent hypoPT was defined as the prescription of active vitamin D supplements for >1 year postoperatively and the assignment of hypoPT codes. The prevalence of persistent hypoPT was estimated at two different levels: minimum and maximum estimations with or without postoperative osteoporosis and/or renal failure codes. Correlates for persistent hypoPT were investigated among several demographic and clinical variables.

RESULTS

Of the 2388 patients, 1752 (73.4%) were women with a mean age of 45 years. The types of diseases were: benign thyroid disease (n = 235), malignant thyroid tumors (n = 1570), Graves ' disease (n = 558), and malignancy combined with Graves' disease (n = 25). The minimum and the maximum estimation of the prevalence of persistent hypoPT were 15.0 and 20.3%, respectively. Multivariate logistic regression analysis showed that the malignant tumor (odds ratio, 1.8) independently correlated with persistent hypoPT.

CONCLUSIONS

The prevalence of persistent hypoPT after total thyroidectomy estimated by the claims-based database was higher than previously recognized. Comprehensive attempts to preserve parathyroid function, especially in malignant diseases, are essential.

Evaluating the safety and efficacy of microwave ablation in treatment of cervical metastatic lymph nodes of papillary thyroid carcinoma compared to repeat surgery

OBJECTIVE

To evaluate the safety and efficacy of microwave ablation (MWA) versus repeat surgery for treating metastatic lymph nodes (MLNs) in papillary thyroid carcinoma (PTC).

METHODS

Between July 2017 and October 2020, 67 patients were enrolled in this retrospective study. 19 and 48 patients underwent MWA and repeat surgery, respectively. The primary and secondary endpoints were recurrence-free survival and complication rates, respectively. The largest diameter, volume and volume reduction ratio (VRR) were analyzed before and after MWA. The effects of different ablation powers on the largest diameter, volume and VRR were investigated. Pre and posttreatment variables (e.g., baseline characteristics, serum thyroglobulin [Tg] levels, hospitalization time, treatment costs, recurrence-free survival and complication rates) were compared between groups.

RESULTS

The largest diameter and volume postablation at each follow-up were smaller than the preablation levels (p < 0.05), except at the 1-month follow-up (p > 0.05). The largest diameter, volume, and VRR among the different ablation powers were not significantly different (p > 0.05). The mean serum Tg levels and biochemical remission rates were not significantly different between the groups (p > 0.05). Compared to reoperation, MWA had a shorter hospitalization time and lower treatment cost (p < 0.001). Total and minor complications were higher in the reoperation group (p < 0.05), but major complications were comparable (p > 0.05). The recurrence-free survival rate between groups was not significantly different (p = 0.401). The 1- and 3-year recurrence-free survival rates were comparable between the groups.

CONCLUSIONS

MWA may be a safe and effective alternative to repeat surgery for treating MLNs of PTC in select patients.

Microwave Ablation Vs Traditional Thyroidectomy for Benign Thyroid Nodules: A Prospective, Non-Randomized Cohort Study

RATIONALE AND OBJECTIVES

To evaluate the efficacy of microwave ablation (MWA) for benign thyroid nodules (BTNs) and compare trauma and complication rates between MWA and traditional thyroidectomy for BTNs.

MATERIALS AND METHODS

84 patients with BTNs were recruited and followed up at 1, 3, 6, and 12months. 56 and 28 patients chose to undergo MWA (group A) and traditional thyroidectomy (group B), respectively. Efficacy was assessed by volume reduction rate (VRR) and therapeutic success rate (TSR) at each follow-up. Trauma was compared using inflammation response parameters, visual analog scale (VAS) scores, quality of life (QOL) and thyroid function measures at 1, 3, and 6 months. Complications rates were also compared.

RESULTS

The VRR was 80.70 ± 18.60%, and TSR was 91.70% at 6-months. Furthermore, the VRR increased to 90.45 ± 11.51%, and TSR increased to 100% at 12-months. C-reactive protein levels were significantly higher in group B on the first postoperative day (POD) (3.89 ± 0.86 mg/mL vs 3.39 ± 0.56 mg/mL, p = 0.002). Visual analog scale scores were significantly lower in group A on the first and second POD. Thyroid stimulating hormone levels were significantly lower in group A at three (1.71 ± 1.12uIU/mL vs 2.37 ± 1.24uIU/mL, p = 0.013) and 6-months (1.34 ± 0.70uIU/mL vs 1.97 ± 0.94uIU/mL, p = 0.002). There were no significant between-group differences in QOL and complication rates.

CONCLUSION

Microwave ablation shows acceptable and promising efficacy. Compared with thyroidectomy, MWA was associated with less trauma and comparable complication rates.

The Use of Harmonic Focus and Thunderbeat Open Fine Jaw in Thyroid Surgery: Experience of a High-Volume Center

Background: In thyroid surgery, achieving accurate haemostasis is fundamental in order to avoid the occurrence of complications. Energy-based devices are currently extensively utilized in this field of surgery. This study aims to compare Harmonic Focus and Thunderbeat Open Fine Jaw with regard to surgical outcomes and complications. Methods: Patients submitted to total thyroidectomy in our center, between January 2017 and June 2020, were retrospectively analysed. Based on the energy-based device utilized, two groups were identified: Group A (Harmonic Focus) and Group B (Thunderbeat Open Fine Jaw). Results: A total of 527 patients were included: 409 in Group A and 118 in Group B. About surgical outcomes, the mean operative time was significantly shorter in Group B than in Group A (p < 0.001), while as regards complications, the occurrence of transient recurrent laryngeal nerve injury was significantly greater in Group B than in Group A (p = 0.019). Conclusions. Both Harmonic Focus and Thunderbeat Open Fine Jaw have proven to be effective devices. Operative times were significantly shorter in thyroidectomies performed with Thunderbeat Open Fine Jaw; however, the occurrence of transient recurrent laryngeal nerve injury was significantly greater in patients operated on with this device.

Transient Hypocalcemia After Total Thyroidectomy: The Obesity Paradox at Work?

INTRODUCTION

With increasing rates of obesity worldwide, a correlation between high body mass index (BMI) and postoperative morbidity after thyroid surgery remains unclear. Postoperative transient hypocalcemia is common after total thyroidectomy due to interruption of parathyroid function. This study examines the relationship between BMI and hypocalcemia after total thyroidectomy.

MATERIALS AND METHODS

A retrospective review of prospectively collected data for 1135 patients who underwent total thyroidectomy for cancer, multinodular goiter (MNG), or Graves' disease between June 2009 and November 2020 at a single institution was performed. BMI groups followed the World Health Organization classification. Hypocalcemia was defined as serum calcium ≤8 mg/dL. Calcium levels measured on postoperative day 0 and the following morning were compared between the BMI groups.

RESULTS

Of 1135 total thyroidectomy patients, 85% were women. The mean age and standard deviation of patients was 49 (± 13) y, with most of Hispanic origin (64%). Overall, 41.5% of patients had cancer, 45% nontoxic MNG, 5.8% toxic MNG, and 12% Graves' disease. Stratified by BMI, 27% of patients were normal, 34% overweight, and 39% obese. Overall, overweight and obese patients experienced less transient hypocalcemia at both time points compared to normal patients postoperatively (P = 0.01 and P = 0.009). Furthermore, overweight and obese patients with Graves' disease experienced less transient hypocalcemia at both time points (P = 0.04 and P = 0.05). There was no statistical difference in other groups.

CONCLUSIONS

A protective role of higher BMI or "obesity paradox" for postoperative hypocalcemia may exist in those obese patients after total thyroidectomy.

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

Objective

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

Methods

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

Results

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

Conclusions

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

Indocyanine Green Angiography of Parathyroid Glands versus Intraoperative Parathyroid Hormone Assay as a Reliable Predictor for Post Thyroidectomy Transient Hypocalcemia

BACKGROUND

Prediction of postoperative hypocalcemia is a fundamental issue in thyroidectomy. Indocyanine green (ICG) angiography of parathyroid glands is a feasible method to detect the perfusion of parathyroid glands and predict postoperative hypocalcemia.

MATERIALS AND METHODS

A prospective observational study was conducted at Ain Shams University Hospitals between April 2018 and April 2021. The included cases of total thyroidectomy underwent intraoperative ICG fluorescence angiography to identify the four parathyroid glands and score each gland according to the viability. Patients in which less than four glands were identified were excluded. Intraoperative intact parathyroid hormone (ioPTH) level assay was also measured to compare with ICG in predicting postoperative transient hypocalcemia.

RESULTS

A total of 134 cases underwent total thyroidectomy during the study period. We could identify the four parathyroid glands in 90 patients, including them in the study. We had postoperative hypocalcemia in 28 cases (31.1%). The diagnostic accuracy of ICG angiography and ioPTH level assay was high and almost similar (82.22% versus 87.78%). Both were higher than the surgeons' diagnostic accuracy of visual inspection (62.22%).

CONCLUSIONS

ICG angiography of the parathyroid gland is a safe, reliable predictor for postoperative transient hypocalcemia with a high and almost similar accuracy compared to intraoperative parathyroid hormone level.

A pilot feasibility study to assess vascularity and perfusion of parathyroid glands using a portable hand-held imager

OBJECTIVES

Intraoperative localization and preservation of parathyroid glands (PGs) are challenging during thyroid surgery. A new noninvasive technique of combined near-infrared PG autofluorescence detection and dye-free imaging angiography that allows intraoperative feedback has recently been introduced. The objective of this study was to evaluate this technique in real-time.

MATERIALS AND METHODS

A pilot feasibility study of a portable imaging device in four patients who underwent either thyroid lobectomy or total thyroidectomy is presented. PG autofluorescence and vascularity/tissue perfusion were monitored using a real-time screen display during the surgical procedure.

RESULTS

Three lobectomies and one total thyroidectomy were performed. Among the nine PGs identified by the operating surgeon, eight PGs were confirmed using the autofluorescence device. Each PG was successfully determined to be either well-perfused or devascularized, and devascularized PGs were autotransplanted.

CONCLUSIONS

The preliminary results suggest that the combination of PG autofluorescence detection and dye-free angiography can potentially be used to assess PG function. With further validation studies, the effectiveness of this technique in clinical practice can be further delineated.

Persistent Postthyroidectomy Hypoparathyroidism in the Netherlands

Importance

Hypoparathyroidism is one of the most common complications after total or completion thyroidectomy. The reported incidence rate of hypoparathyroidism in the literature is highly variable. Data that provide a better understanding of the magnitude of this postoperative complication are warranted and can provide a stepping stone for further collaborations that aim to reduce complication rates and establish uniform treatment protocols.

Objective

To evaluate the incidence of postoperative, persistent hypoparathyroidism after total or completion thyroidectomy in patients who were referred to university hospital centers and assess the association of different definitions with the incidence of hypoparathyroidism.

Design, Setting, and Participants

This retrospective multicenter cohort study conducted throughout 2016 in 7 Dutch university hospital centers included 200 patients who were undergoing a total or completion thyroidectomy. Data analysis was conducted in January 2021.

Main Outcomes and Measures

We report on the incidence of persistent hypoparathyroidism, defined as the need for active vitamin D with or without calcium supplementation longer than 1 year after surgery.

Results

A total of 200 patients (143 women [71.5%]; mean [IQR] age, 49.0 [37.0-62.0] years) were included and 30 patients (15.0%) developed persistent hypoparathyroidism. The incidence of persistent hypoparathyroidism varied between 14.5% (calcium and active vitamin D 1 year postsurgery) to 28.5% (calcium and/or active vitamin D 6 months postsurgery) depending on the definition used.

Conclusions and Relevance

In this cohort study, the risk of persistent hypoparathyroidism after total or completion thyroidectomy was 15% in patients who were referred to university hospital centers. The high rate of persistent hypoparathyroidism warrants efforts to reduce this complication rate. There is discrepancy in the definition and treatment of persistent hypoparathyroidism, and use of uniform evidence-based treatment guidelines enables comparison of interventions.

Intraoperative Indocyanine Green Angiography of Parathyroid Glands and the Prevention of Post-Thyroidectomy Hypocalcemia

BACKGROUND

We compared the reliability of indocyanine green (ICG) angiography and intraoperative PTH levels for predicting early post-thyroidectomy hypocalcemia.

METHODS

Prospective study of 94 patients (71% women, mean age 53.7 years) undergoing total thyroidectomy. An ICG score of 2 (white) indicated a well-vascularized gland. PTH preoperative levels-PTH postresection levels divided by preoperative PTH × 100 was used to determine the PTH decline percentage. A decrease of at least 62.5% or <17.1 pg/mL in ioPTH was the criterion for predicting hypocalcemia.

RESULTS

At surgery, the four parathyroid glands were identified in 50 (53.2%) patients and <4 glands in 44. Calcium supplements were needed by 22 patients (23.4%) postoperatively, 11 patients in each group of 4 and <4 parathyroid glands identified. The diagnostic accuracy of ICG angiography (0.883, 95% confidence interval [CI] 0.800-0.940) and ioPTH (0.862, 95% CI 0.775-0.92) was similar. When all four parathyroid glands were identified, ICG angiography showed a slightly higher diagnostic accuracy, specificity and positive predictive than ioPTH levels, but when < 4 glands were identified, the ioPTH showed a slightly higher diagnostic accuracy, specificity and positive predictive value. Differences were not statistically significant for any of the comparisons.

CONCLUSIONS

The presence of one well-perfused parathyroid gland (ICG score 2) using ICG angiography or ioPTH decline, measured before and after completion of thyroid surgery, is both reliable methods in prediction of early post-thyroidectomy hypocalcemia independently of the number of glands identified intraoperatively.

Thyroidectomy for Cancer: The Surgeon and the Parathyroid Glands Sparing

BACKGROUND

The diagnosis of thyroid cancer is continuously increasing and consequently the amount of thyroidectomy. Notwithstanding the actual surgical skill, postoperative hypoparathyroidism still represents its most frequent complication. The aims of the present study are to analyze the rate of postoperative hypoparathyroidism after thyroidectomy, performed for cancer by a single first operator, without any technological aid, and to compare the data to those obtained adopting the most recent technological adjuncts developed to reduce the postoperative hypoparathyroidism.

METHODS

During the period 1997-2020 at the Endocrine Surgery Unit of the Department of Clinical and Experimental Medicine of the University of Florence, 1648 consecutive extracapsular thyroidectomies for cancer (401 with central compartment node dissection) were performed. The percentage of hypoparathyroidism, temporary or permanent, was recorded both in the first period (Group A) and in the second, most recent period (Group B). Total thyroidectomies were compared either with those with central compartment dissection and lobectomies. Minimally invasive procedures (MIT, MIVAT, some transoral) were also compared with conventional. Fisher's exact and Chi-square tests were used for comparison of categorical variables. p < 0.01 was considered statistically significant. Furthermore, a literature research from PubMed® has been performed, considering the most available tools to better identify parathyroid glands during thyroidectomy, in order to reduce the postoperative hypoparathyroidism. We grouped and analyzed them by technological affinity.

RESULTS

On the 1648 thyroidectomies enrolled for the study, the histotype was differentiated in 93.93 % of cases, medullary in 4% and poorly differentiated in the remaining 2.06%. Total extracapsular thyroidectomy and lobectomy were performed respectively in 95.45% and 4.55%. We recorded a total of 318 (19.29%) cases of hypocalcemia, with permanent hypoparathyroidism in 11 (0.66%). In regard to the literature, four categories of tools to facilitate the identification of the parathyroids were identified: (a) vital dye; (b) optical devices; (c) autofluorescence of parathyroids; and (d) autofluorescence enhanced by contrast media. Postoperative hypoparathyroidism had a variable range in the different groups.

CONCLUSIONS

Our data confirm that the incidence of post-surgical hypoparathyroidism is extremely low in the high volume centers. Its potential reduction adopting technological adjuncts is difficult to estimate, and their cost, together with complexity of application, do not allow immediate routine use. The trend towards increasingly unilateral surgery in thyroid carcinoma, as confirmed by our results in case of lobectomy, is expected to really contribute to a further reduction of postsurgical hypoparathyroidism.

Is There a Regular Pattern in the Recovery of Parathyroid Function After Thyroid Cancer Surgery?

Purpose

To investigate whether there is a pattern of recovery of parathyroid function after thyroid cancer surgery.

Patients and Methods

The study included 183 patients with papillary thyroid cancer (PTC) who underwent “total thyroidectomy (TT)” plus “unilateral central lymph node dissection (UCLND)” or “bilateral central lymph node dissection (BCLND)”. The intact parathyroid hormone (iPTH) and serum calcium (sCa) were analyzed several times within 1 month after surgery to explore the recovery pattern of parathyroid gland function. Then, these 183 cases were divided into group A (97 cases) with UCLND and group B (86 cases) with BCLND to analyze whether the impairment and recovery of parathyroid function were different between the two subgroups.

Results

Postoperative hypoparathyroidism was seen in 115 out of 183 cases. iPTH values decreased significantly on postoperative day (POD) 1 compared with preoperative values, dropped to the lowest point on POD 3, showed an increasing trend on POD 5 and 14, and increased to 85.0% of preoperative values at POD30, whereas changes in sCa differ from changes in iPTH, which showed the lowest sCa value on POD1, and rebounded on the POD3 with the intervention of calcium supplementation, and continued to rise on the POD5 and POD14, and the sCa value reached 96.6% of the preoperative level at POD30. Subgroup analysis showed that temporary hypoparathyroidism was more pronounced in group B than in group A. SCa and iPTH levels in both subgroups showed the same trend of first decrease and then increase.

Conclusion

The recovery of hypocalcemia and hypo-iPTHemia in the first month after thyroid cancer surgery shows a trend of decreasing and then increasing, and knowing the recovery of parathyroid function at different time points is of great value to surgeons and patients alike.

[The clinical practice guidelines for primary hyperparathyroidism, short version]

Primary hyperparathyroidism (PHPT) is an endocrine disorder of parathyroid glands characterized by excessive secretion of parathyroid hormone (PTH) with an upper normal or elevated blood calcium level. Classical PHPT refers to a symptomatic, multi-system disorder, wich can lead to a significant decrease in the quality of life, disability of patients, and even an increased risk of premature death. Hypercalcemia and the catabolic effect of PTH on various cells are considered as the main pathogenetic mechanisms of the PHPT associated complications. In the last two decades, there has been an increase in the incidence of PHPT, mainly due to the mild forms of the disease, primarily due to the routine calcium screening in North America, Western Europe and, Asia. High prevalence of the disease, as well as the variety of clinical manifestations, cause the attention of different specialists - physicians, rheumatologists, urologists, nephrologists, cardiologists and other doctors. This review cover the main issues of Russian guidelines for the management of PHPT, approved in 2020, including laboratory and instrumental methods, differential diagnosis, surgical and conservative approach, short-term and long-term follow-up. This guidelines also include the recommendations for special groups of patients with hereditary forms of PHPT, parathyroid carcinoma, PHPT during pregnancy.

Association between number of parathyroid glands identified during total thyroidectomy and functional parathyroid preservation

Purpose

Systematic identification of all 4 parathyroid glands has been recommended during total thyroidectomy (TT); however, it is unclear whether this strategy necessarily translates into optimized functional parathyroid preservation. We wished to investigate the association between number of parathyroids identified intraoperatively during TT, and incidence of incidental parathyroidectomy, and postoperative hypoparathyroidism.

Methods

Retrospective review of prospectively maintained database of 511 consecutive patients undergoing TT at an academic teaching hospital. The association between number of parathyroid glands identified intraoperatively and incidence of biochemical hypocalcaemia (defined as any calcium < 2 mmol/L n first 48 h after surgery), symptomatic hypocalcaemia; permanent hypoparathyroidism (defined as any hypocalcaemia or need for calcium or vitamin D > 6 months after surgery), and incidental parathyroidectomy, was investigated. The association between number of parathyroid glands visualized and postoperative parathyroid hormone (PTH) levels was investigated in a subset of 454 patients.

Results

Patients in whom a greater number of parathyroids had been identified had a significantly higher incidence of biochemical and symptomatic hypocalcaemia, and significantly lower postoperative PTH levels, than patients with fewer glands identified. There were no significant differences in incidence of permanent hypoparathyroidism or incidental parathyroidectomy. On multivariate analysis, malignancy, Graves disease, and identification of 3–4 parathyroids were independent predictors of biochemical hypocalcaemia. For symptomatic hypocalcaemia, identification of 2–4 parathyroids, and identification of 3–4 parathyroids, were significant.

Conclusions

Systematic identification of as many parathyroid glands as possible during TT is not necessary for functional parathyroid preservation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00423-021-02287-6.

Radiofrequency ablation versus reoperation for benign thyroid nodules that developed after previous thyroid surgery

PURPOSE

To compare the clinical outcomes of radiofrequency ablation (RFA) versus reoperation for benign thyroid nodules that developed after previous thyroid surgery.

METHODS

A total of 53 patients with 53 benign nodules developed after previous thyroid surgery were evaluated in this retrospective study. Eighteen patients were treated by RFA (RFA group) and 35 patients underwent reoperation (reoperation group). The efficacy, safety, thyroid function, blood loss, hospitalization, total treatment time, and cost were compared between the two groups.

RESULTS

In the RFA group, the mean volume decreased significantly from 12.78 ± 17.57 ml to 0.94 ± 1.01 ml (p = 0.043) with a volume reduction rate of 85.27 ± 14.35% and significant improvement in symptom and cosmetic scores (all p = 0.001). Therapeutic efficacy was achieved with a single session in all thyroid nodules. The total treatment time (6.12 ± 3.17 min vs. 110.26 ± 44.41 min, p < 0.001), blood loss (0 ml vs. 82.58 ± 105.55 ml, p < 0.001) and hospitalization(0 days vs. 9.66 ± 4.28 days, p < 0.001) were significantly lower in the RFA group than those in reoperation group, but the costs of treatment were similar(2262.12 ± 221.54 USD vs. 2638.04 ± 1062.90 USD, p = 0.081). The incidence of complications was significantly higher in the reoperation group than in the RFA group(31.43 vs. 0%, p < 0.001). Furthermorre, 65.17% of patients developed hypothyroidism after reoperation, whereas the thyroid function of the patients in the RFA group was unaffected.

CONCLUSION

For patients with benign thyroid nodules developed after previous thyroid surgery, RFA can be considered as a safe and effective alternative to reoperation with advantages of maintenance of intact thyroid function and low incidence of complications.

Intraoperative indocyanine green (ICG) angiography of the parathyroids glands in prediction of post-thyroidectomy hypocalcemia: Diagnostic accuracy of the ICG score 2 versus the 4-ICG score

INTRODUCTION

Indocyanine green (ICG) angiography of the parathyroids is useful in prediction of postthyroidectomy hypocalcemia. We compared the diagnostic accuracy of a single-gland ICG score of 2 with a score estimated by adding the viability value of the four glands (4-ICG).

METHODS

Fifty patients (66% women, median age 49.4 years) underwent total thyroidectomy with identification of all 4 glands. The degree of ICG was classified as 0, black (nonvascularized), 1, gray/heterogeneous (partially vascularized), and 2, white (well vascularized).

RESULTS

The diagnostic accuracy of the optimal cut-off of the 4-ICG sum score ≤3 was 84% (95% CI 70.9-92.8) lower than the diagnostic accuracy of 92% (80.8-97.8) of the ICG score 2. Both scores identified 2 false negative cases, but the rates of false positives were lower with the ICG score 2 (18.2% vs. 57.1%).

CONCLUSIONS

Identification of single-gland ICG score of 2 has a higher diagnostic accuracy than 4-ICG sum score to predict immediate hypocalcemia after total thyroidectomy.

Use of pre-operative calcium and vitamin D supplementation to prevent post-operative hypocalcaemia in patients undergoing thyroidectomy: a systematic review

OBJECTIVE

This systematic review aimed to establish the evidence behind the use of pre-operative calcium, vitamin D or both calcium and vitamin D to prevent post-operative hypocalcaemia in patients undergoing thyroidectomy.

METHOD

This review included prospective clinical trials on adult human patients that were published in English and which studied the effects of pre-operative supplementation with calcium, vitamin D or both calcium and vitamin D on the rate of post-operative hypocalcaemia following total thyroidectomy.

RESULTS

Seven out of the nine trials included reported statistically significantly reduced rates of post-operative laboratory hypocalcaemia (absolute risk reduction, 13-59 per cent) and symptomatic hypocalcaemia (absolute reduction, 11-40 per cent) following pre-operative supplementation.

CONCLUSION

Pre-operative treatment with calcium, vitamin D or both calcium and vitamin D reduces the risk of post-operative hypocalcaemia and should be considered in patients undergoing total thyroidectomy.

Risks and prediction of postoperative hypoparathyroidism due to thyroid surgery

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

Cost-effectiveness of computed tomography nodal scan in patients with papillary thyroid carcinoma

OBJECTIVES

This study evaluates the cost-effectiveness of ultrasound (US) only; computed tomography (CT) only; and combined US-CT in a base-case that underwent total thyroidectomy for a newly diagnosed papillary thyroid carcinoma (PTC) (scenario I) or surgery for recurrent disease (scenario II).

MATERIALS AND METHODS

Markov chain model was developed comparing the above modalities. Follow-up time was set as 10 years. Costs and probabilities values are obtained from literature and the National Cancer Database.

RESULTS

Nodal mapping of the central compartment in both primary and recurrent PTC scenarios demonstrated combined utilization of preoperative US and CT is preferred over the use of US or CT separately; the final incurred management cost was [scenario I: U.S.$10,548.25 - scenario II: U.S.$11.197.88] and effectiveness was [scenario I: 6.875 Quality-adjusted-life-year (QALY) - scenario II: 6.871 QALY]. Nodal mapping of the lateral compartments favored US alone as the cost-effective modality in both scenarios; the final incurred management cost was [scenario I: U.S.$10,716.60 - scenario II: U.S.$11,247.92] and effectiveness was [scenario I: 6.879 QALY - scenario II: 6.883 QALY]. Sensitivity analysis demonstrated that for combined utilization of US and CT scans to remain cost-effective, the cost of a CT scan should be less than U.S.$1,127.54.

CONCLUSIONS

Based on the model, combined utilization of US and CT is cost-effective in nodal mapping patients with PTC.

Intraoperative indocyanine green (ICG) angiography of the parathyroids glands in prediction of post-thyroidectomy hypocalcemia: Diagnostic accuracy of the ICG score 2 versus the 4-ICG score

INTRODUCTION

Indocyanine green (ICG) angiography of the parathyroids is useful in prediction of postthyroidectomy hypocalcemia. We compared the diagnostic accuracy of a single-gland ICG score of 2 with a score estimated by adding the viability value of the four glands (4-ICG).

METHODS

Fifty patients (66% women, median age 49.4 years) underwent total thyroidectomy with identification of all 4 glands. The degree of ICG was classified as 0: black (nonvascularized), 1: gray/heterogeneous (partially vascularized), and 2: white (well vascularized).

RESULTS

The diagnostic accuracy of the optimal cut-off of the 4-ICG sum score ≤3 was 84% (95% CI: 70.9-92.8) lower than the diagnostic accuracy of 92% (80.8-97.8) of the ICG score 2. Both scores identified 2 false negative cases, but the rates of false positives were lower with the ICG score 2 (18.2 vs. 57.1%).

CONCLUSIONS

Identification of single-gland ICG score of 2 has a higher diagnostic accuracy than 4-ICG sum score to predict immediate hypocalcemia after total thyroidectomy.

Thyroid neoplasm in Makkah region, Saudi Arabia. A retrospective epidemiological study

Objectives:

To improve our local data and demographics of thyroid neoplasm in Makkah region, Kingdom of Saudi Arabia and provide some basic statistics for future studies in our local community.

Methods:

A record based retrospective epidemiological study was conducted and included 314 thyroid disease patients who were presented to our centers at Makkah region, Kingdom of Saudi Arabia between December 2009 and December 2019.

Results:

A descriptive statistical analysis was carried out. The average age was 42.77 years, with a female-to-male ratio of 3:1, and most of the patients were Saudi (77%). Fifty-seven percent of cases were benign, while in malignant cases, 33.4% were papillary thyroid carcinoma. The mean follow-up time was 15.44 months, with excellent compliance in 39.4% of the patients.

Conclusion:

Thyroid tumors have a leading incidence in head and neck tumors in Makkah, Kingdom of Saudi Arabia, mandating further studies to determine the causes and distribution in other regions of the country.

Hypoparathyroidism in Pregnancy and Lactation: Current Approach to Diagnosis and Management

Background: Hypoparathyroidism is an uncommon endocrine disorder. During pregnancy, multiple changes occur in the calcium-regulating hormones, which may affect the requirements of calcium and active vitamin D during pregnancy in patients with hypoparathyroidism. Close monitoring of serum calcium during pregnancy and lactation is ideal in order to optimize maternal and fetal outcomes. In this review, we describe calcium homeostasis during pregnancy in euparathyroid individuals and also review the diagnosis and management of hypoparathyroidism during pregnancy and lactation. Methods: We searched the MEDLINE, CINAHL, EMBASE, and Google scholar databases from 1 January 1990 to 31 December 2020. Case reports, case series, book chapters, and clinical guidelines were included in this review. Conclusions: During pregnancy, rises in 1,25-dihydroxyvitamin D (1,25-(OH)2-D3) and PTH-related peptide result in suppression of PTH and enhanced calcium absorption from the bowel. In individuals with hypoparathyroidism, the requirements for calcium and active vitamin D may decrease. Close monitoring of serum calcium is advised in women with hypoparathyroidism with adjustment of the doses of calcium and active vitamin D to ensure that serum calcium is maintained in the low-normal to mid-normal reference range. Hyper- and hypocalcemia should be avoided in order to reduce the maternal and fetal complications of hypoparathyroidism during pregnancy and lactation. Standard of care therapy consisting of elemental calcium, active vitamin D, and vitamin D is safe during pregnancy.

Association of Hypocalcemia and Magnesium Disorders With Thyroidectomy in Commercially Insured Patients

Importance

Hypocalcemia is a common complication of total thyroidectomy.

Objectives

To identify factors associated with hypocalcemia after total thyroidectomy and to explore the association between hypocalcemia, magnesium disorders, and costs of care.

Design, Setting, and Participants

A retrospective cross-sectional analysis was performed using data from the MarketScan Commercial Claim and Encounters database on 126 766 commercially insured patients younger than 65 years undergoing total thyroidectomy between January 1, 2010, and December 31, 2012. Statistical analysis was performed from January 1, 2016, to May 30, 2019.

Main Outcomes and Measures

Short- and long-term hypocalcemia and the costs of care were examined using multivariable regression modeling.

Results

Among the 126 766 patients in the study (81.6% women; mean age, 46.5 years [range, 18-64 years]), postoperative hypocalcemia was present in 19.1% of patients in the initial 30-day postoperative period and in 4.4% of patients at 1 year. Magnesium disorders were present in 2.1% of patients at the time of surgery. Short- and long-term hypocalcemia were significantly more likely in women (short-term: odds ratio [OR], 1.39 [95% CI, 1.29-1.50]; long-term: OR, 1.69 [95% CI, 1.52-1.89]), those younger than 40 years (short-term: OR for ages 40-64 years, 0.83 [95% CI, 0.78-0.87]; long-term: OR for ages 40-64 years, 0.73 [95% CI, 0.67-0.79]), those with a diagnosis of thyroiditis (short-term: OR, 1.48 [95% CI, 1.16-1.89]; long-term: OR, 1.60 [95% CI, 1.13-2.26]) or cancer (short-term: OR, 1.32 [95% CI, 1.05-1.67]; long-term: OR, 1.17 [95% CI, 0.83-1.63]), vitamin D deficiency (short-term: OR, 1.96 [95% CI, 1.74-2.21]; long-term: OR, 3.72 [95% CI, 3.30-4.18]), concurrent lateral neck dissection (short-term: OR, 1.51 [95% CI, 1.37-1.66]; long-term: OR, 1.95 [95% CI, 1.69-2.26]), concurrent central neck dissection (short-term: OR, 1.15 [95% CI, 1.07-1.24]; long-term: OR, 1.25 [95% CI, 1.12-1.40]), intraoperative parathyroid (short-term: OR, 1.58 [95% CI, 1.46-1.71]; and long-term: OR, 2.05 [95% CI, 1.82-2.31]) or recurrent laryngeal nerve injury (short-term: OR, 1.49 [95% CI, 1.27-1.74]; long-term: OR, 2.04 [95% CI, 1.64-2.54]), and magnesium disorders (short-term: OR, 8.40 [95% CI, 7.21-9.79]; long-term: OR, 25.23 [95% CI, 19.80-32.17]). Compared with the initial postoperative period, the odds of hypocalcemia decreased by 90.0% (OR, 0.10 [95% CI, 0.09-0.11]) at 6 months and 93.0% (OR, 0.07 [95% CI, 0.06-0.08]) at 1 year. After controlling for all other variables, magnesium disorders were associated with the highest odds of short- and long-term postoperative hypocalcemia. Hypocalcemia ($3392) and magnesium disorders ($14 314) were associated with increased mean incremental 1-year costs of care.

Conclusions and Relevance

Hypocalcemia is common after total thyroidectomy but resolves in most patients by 1 year. Magnesium disorders are significantly independently associated with short- and long-term hypocalcemia and are associated with greater costs of care. These data suggest a potentially modifiable target to reduce the incidence and cost of long-term hypocalcemia at patient and systemic levels.