Relationship between hypoparathyroidism and the number of parathyroid glands preserved during thyroidectomy

Patient satisfaction and operator proficiency in gasless transaxillary endoscopic thyroidectomy under IONM: a retrospective cohort study

Background

This study aims to evaluate the surgical safety and effectiveness of gasless transaxillary endoscopic thyroidectomy (GTET), assess patients' short-term perceptions and long-term outcomes, and delineate the learning curve and key surgical techniques of the operators.

Materials and methods

Clinicopathological and postoperative follow-up data from patients with unilateral thyroid cancer in the same period were collected. These patients were divided into the GTET group and the traditional open surgery group to compare and analyze the differences and explore the factors affecting the learning curve of GTET.

Results

Patients who chose GTET had better general health and thyroid conditions than those in the open group, and the quality of postoperative life was better in the GTET group than in the open group, with the main differences between the two groups being appearance and neck and shoulder function. The GTET learning curve in this study peaked at 19 cases, with slight differences between left and right, and a larger sample size is still needed to explore the factors affecting the learning curve.

Conclusions

GTET has a reliable safety and efficacy profile for patients with unilateral thyroid cancer. Intraoperative nerve monitoring (IONM) techniques require some adaptation in GTET. In some respects, patients' postoperative experience and quality of life are superior to those of conventional open surgery. There is a learning curve for GTET, but large samples are still needed to explore its true significance.

Guideline From the Brazilian Society of Surgical Oncology and Brazilian College of Surgeons in Preventing and Managing Acute Hypoparathyroidism After Thyroid Surgery

The risk of hypoparathyroidism and hypocalcemia is a critical concern in thyroid surgery. Preserving parathyroid gland vascularization during surgery is essential for effective prevention. Preoperative and postoperative management, including calcium and Vitamin D supplementation, is paramount. Measurement of parathyroid hormone levels after surgery is the best predictor of hypoparathyroidism. This guideline offers recommendations for the prevention, diagnosis, and treatment of acute hypoparathyroidism and hypocalcemia after thyroid surgery.

Hypoparathyroidism after total thyroidectomy: reactive to symptoms supplementation

INTRODUCTION

After total thyroidectomy (TT), postoperative hypoparathyroidism (PH) is the most frequent complication. Yet, management strategies for PH remain disputed. The aim of this study was to evaluate outcomes of a reactive supplementation in case of symptomatic PH. Additionally, risk factors for symptomatic PH and readmission due to PH were analyzed.

MATERIALS AND METHODS

All consecutive patients who underwent TT or completion from 2017 to 2022 were considered for inclusion. During this period, a reactive to symptom vitamin-calcium supplementation was used. The primary outcome was the occurrence of severe PH after discharge resulting in readmission.

RESULTS

Overall, 307 patients were included, of which 98 patients (31.9%) developed symptomatic PH including 43 patients before discharge. Independent risk factors for developing symptomatic PH were age (p = 0.010) and postoperative day 1 (POD1) PTH level (p < 0.001). Overall, 264 patients (86%) did not present PH before discharge and were discharged home. Among them, 55 patients (20.8%) experienced symptomatic PH, requiring readmission in 18 patients. The overall readmission rate owing to symptomatic PH requiring intravenous supplementation despite oral vitamin-calcium supplementation was 6.8% (n = 18). Independent risk factors for symptomatic PH-related readmission were age (p = 0.007) and POD1 PTH level (p < 0.001). Adequate cut-off values for predicting readmission were POD1 albumin-adjusted calcium = 2.1 mmol/l (Sensibility = 0.95, Specificity = 0.30) and POD1 PTH = 11.5 pg/ml (Sensibility = 0.90, Specificity = 0.71).

CONCLUSION

Supplementing only symptomatic patients was safe and efficient. This attitude does not alter on morbidity, mortality or readmission rate which is in line with current literature.

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.

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.

Factors affecting the rates of incidental parathyroidectomy during thyroidectomy

BACKGROUND

The most important factors affecting the development of postoperative hypocalcaemia (PH) include intraoperative trauma to the parathyroid glands, incidental parathyroidectomy (IP), and the surgeon's experience. In this study, we aimed to determine the incidence of IP, evaluate its effect on postoperative calcium levels and investigate the effect of surgeon experience and volume on IP incidence and postoperative calcium levels.

METHODS

This retrospective study included 645 patients who underwent thyroid surgery at the Department of General Surgery, Kütahya Health Sciences University between September 2016 and March 2020. All patients underwent surgery at a single clinic by general surgeons experienced in thyroid surgery and their residents (3-5 years).

RESULTS

Normal parathyroid glands were reported in 58 (8.9%) of 645 patients. In 5 (8.6%) of 58 patients the parathyroid gland was detected in the intrathyroidal region. PH developed in ten patients (17.2%) with incidental removal of the parathyroid glands. A statistically significant difference was found between the number of incidentally removed parathyroid glands and the development of hypocalcaemia (p<0.05). Normal parathyroid glands were reported in the pathology of 37 (7.9%) patients operated on by general surgeons and 22 (12.6%) patients operated on by their residents. PH developed in 39 (8.2%) patients operated on by general surgeons and in 8 (4.5%) patients operated on by their residents.

CONCLUSIONS

We found that the complication rate during the resident training process was the same as that of experienced general surgeons. A thyroidectomy can be safely performed by senior residents during residential training.

Ultrasound characteristics of normal parathyroid glands and analysis of the factors affecting their display

BACKGROUND

Parathyroid glands are important endocrine glands, and the identification of normal parathyroid glands is crucial for their protection. The aim of this study is to explore the sonographic characteristics of normal parathyroid glands and analyze the factors affecting their display.

METHODS

Seven hundred three subjects who underwent physical examination at our hospital were included. The number, location, size, morphology, echogenicity and blood flow distribution of parathyroid glands were recorded. The ultrasound characteristics and display rate were also summarized. Meanwhile, shear wave elastography was performed in 50 cases to provide the stiffness measurements, and 26 cases received contrast-enhanced ultrasonography for the assessment of microcirculatory perfusion. Furthermore, we analyzed the factors affecting parathyroid display, including basic information of the subjects and ultrasound features of the thyroid.

RESULTS

① A total of 1038 parathyroid glands were detected, among which, 79.29% were hyperechoic, 20.71% were isoechoic, 88.15% were oval-shaped, and 86.71% had blood flow of grade 0-I. ② 81.79% of the subjects had at least one parathyroid gland detected. ③ The Emean, Emax, PI and AUC of the parathyroid glands were significantly lower than those of the adjacent thyroid tissue (P < 0.05). ④ The display of normal parathyroid glands was related to BMI, thyroid echogenicity and thyroid volume of the subjects (P < 0.05).

CONCLUSIONS

Normal parathyroid glands tend to appear as oval-shaped hyperechoic nodules with blood flow of grade 0-I. BMI, thyroid echogenicity and thyroid volume are independent factors affecting the display of parathyroid glands.

Impact of Clinico Pathological and Surgical Related Risk Factor in Post Operative Hypoparathyroidism in Total Thyroidectomy Patients

Multiple risk factors have been predicted in post operative hypoparathyroidism in total thyroidectomy patients but none have been clearly defined. Present study aims at evaluating the clinic pathological and surgical impact factors in predicting the risk of post operative hypoparathyroidism in thyroidectomy patients. The study was done in Karpaga Vinayaga Institute of Medical Science and Research Centre where Retrospective prospective cohort study who underwent and undergoing total thyroidectomy with or without central neck dissection for both benign and malignant thyroid disorders during 2014 to 2022 was analyzed. The study has analyzed the various risk factors from clinic pathological and surgical skills of identifying the Inferior thyroid artery at its origin and tracing the branches to the parathyroid gland and evaluating the incidence of hypocalcemia in both study and control groups. Two groups were analyzed during the period 2014 to 2022. The study group was included patients with thyroidectomy where ITA were identified and traced up to the parathyroid gland. They were further classified into category A where both sides ITA were identified and saved, category B where only one side was preserved. In control group, the surgery was done only on basis of capsular dissection and peripheral ligation of vessels close to the gland. Total study participants in our study was 416. The overall prevalence of hypocalcemia in our study was 11.4%. The age, gender and pathological variants were comparable between the two groups. Female preponderance (76%) was seen among both the groups. Among total study subjects who underwent total thyroidectomy 44.8% were having multi nodular goitre, 7.3% toxic goitre, 9.8% follicular adenoma, 30.2% papillary carcinoma and 7.9% follicular carcinoma. In our study benign and malignant thyroid disorders had no significant difference. Prevalence of hypocalcemia among control group 14.5% vs study group 3.8%. We found incidence of hypocalcaemia was comparitively lesser among patients with thyroidectomy alone, than those with unilateral or bilateral CND. Prevalence of hypocalcemia among control group was 33% (45/133) and study group 7% (12/153), when thyroidectomy alone was done. However, with neck dissection in bilateral CND, incidence was 41% (23/56) in study group and 61% (11/18) in control group. In unilateral CND, study and control group had 31% (10/32) and 54% (13/24) which was found to be statistically significant. Parathyroid auto transplantation among the control group (29%) compared to the study group (16%). Bilateral neck dissection and gross extrathyroidal extension and cases with PTG inadvertent removal posed significant risk factors for hypoparathyroidism. The prevalence of immediate hypocalcemia among Cat A, Cat B and control group were 14%, 20.3% and 37.5% respectively and was statistically significant (P < .0001). Symptomatic and Biochemical hypocalcemia at the end of 1 week among Cat A, Cat B, and control group was 8%, 12%, and 33.6, & 12.9%, 21% and 30% respectively. Whereas transient hypocalcemia reported among these groups was 1.6%, 5% and 14.6%. Permanent hypocalcemia was < 1% in study group and 4% among control group. We observed that permanent hypocalcemia was high among patients with bilateral neck dissection and auto transplanted PTG. There was no significant statistical difference in hypocalcemia (transient or permanent) among study and control group, but the incidence of hypocalcemia had significantly reduced in both study groups when unilateral or bilateral identification of ITA was done compared to control group. Our hypothesis in this study aims at preserving the branches of ITA supplying PTG distally has greater functional preservation of the parathyroid than conventional technique. This technique also helps us maintaining the plane and capsular dissection if done properly. By trying to preserve the ITA surgeons may acquire better meticulous dissection skills and understanding the anatomical variation of vessels around PTG more precisely which improve the surgical outcome in preventing both transient and permanent hypocalcaemia.

Factors influencing the success of cryopreserved parathyroid autotransplantation: A systematic review

Permanent hypoparathyroidism is a postoperative complication of thyroid and parathyroid surgery and can be cured by cryopreserved parathyroid autotransplantation (CPAT). However, due to the lack of unified and standardized guidelines, the limited ability of the parathyroid tissue itself to withstand cryopreservation, and some yet-to-be-defined processes or technologies, the success rate of cryopreserved parathyroid autotransplantation varies between institutions; it is low for some institutions and high for others. Due to the sparsity of data, views vary on which factors most influence the success rate of cryopreserved parathyroid autotransplantation. In this review, we analyzed the following probable influencing factors: ischemic period before cryopreservation; processes of cryopreservation and thawing, including freezing medium; freezing and thawing methods; duration of cryopreservation; examination of the graft before transplantation; graft site; mass of transplanted tissue fragments; blood calcium level; and the evaluation criteria for cryopreserved parathyroid autotransplantation success. Although the effects of these factors are debatable, we hypothesized that examining them in the above-given order to determine whether they affect the success rate of cryopreserved parathyroid autotransplantation could be beneficial to maximizing the success rate. Our findings led us to conclude that cryopreserved parathyroid autotransplantation operations should be standardized. Standardized guidelines for cryopreserved parathyroid autotransplantation that include such factors as ischemic period time, freezing and thawing methods, and recipient status should be established based on a comprehensive analysis of these factors.

Incidence and risk factors of hypoparathyroidism and hypocalcemia after hemithyroidectomy

PURPOSE

The incidence and risk factors for hypoparathyroidism after total thyroidectomy is well-known. However, the characteristics of hypoparathyroidism and hypocalcemia after hemithyroidectomy have not been investigated well. In this study, we aimed to evaluate the incidence, characteristics, and risk factors of hypoparathyroidism and hypocalcemia after hemithyroidectomy.

METHOD

We retrospectively analyzed the medical data of 321 patients who underwent hemithyroidectomy, with or without central neck dissection, from January 2012 to April 2019. We analyzed the serum intact parathyroid hormone (iPTH), calcium, and ionized calcium (iCa) levels serially (preoperatively and postoperatively on the operation day; days 1 and 3; and months 1, 3, 6, and 12) and evaluated risk factors for postoperative hypoparathyroidism and hypocalcemia.

RESULTS

The mean iPTH and calcium levels decreased significantly after hemithyroidectomy on the operation day and postoperative days 1 and 3, and returned to the preoperative level at the postoperative 1-month follow-up. The mean iCa level decreased significantly on the operation day and postoperative day 1. Transient hypoparathyroidism and transient hypocalcemia occurred in 16 (5%) and 250 (78%) participants, and they recovered to normal levels postoperatively by 1 month. Eight (2.5%) patients had mild symptoms of hypocalcemia necessitating oral calcium supplementation. No permanent hypoparathyroidism or hypocalcemia was observed. Preoperatively low serum iPTH and calcium levels were associated with transient hypoparathyroidism and hypocalcemia after hemithyroidectomy.

CONCLUSION

Approximately 5% and 2.5% of participants showed transient hypoparathyroidism and mild symptomatic hypocalcemia after hemithyroidectomy. The risk factors for transient hypoparathyroidism and hypocalcemia include preoperative low serum iPTH and calcium levels.

Transoral endoscopic thyroidectomy vestibular approach (TOETVA): initial experience in Australia

BACKGROUND

Thyroidectomy is traditionally an open procedure. The potential for and unpredictability of patients developing an unsightly anterior neck scar has led many investigators to develop various 'scarless' thyroidectomy techniques. Here we report on our initial experience, and to our knowledge, the first and largest series of this technique in Australia and New Zealand.

METHODS

Across two centres in Western Australia, three Endocrine surgeons utilized the Transoral Endoscopic Thyroidectomy vestibular approach (TOETVA). Key endpoints such as operating time, blood loss, pain scores, recurrent laryngeal nerve injury and hypoparathyroidism was collected. Data was analysed using R statistical program.

RESULTS

One hundred and two TOETVAs were performed between March 2018 and May 2021. There were 66 hemithyroidectomies, 34 total thyroidectomies (four converted to open), and two isthmusectomies. We noted a trend in median operating time decreasing over the study period. There were no cases of permanent recurrent laryngeal nerve palsy, wound infection, seroma or haematoma. We had four instances of open conversion; one temporary RLN palsy, and 12 cases of temporary hypoparathyroidism.

CONCLUSION

This is the first series of TOETVA reported in Australia and New Zealand. Our results demonstrate that with appropriate surgeon experience, training, collaboration, and in well selected patients, this is a feasible and safe thyroidectomy technique. We hope that our work will build confidence in Endocrine Surgical units seeking to develop this technique in Australia.

Total areola approach for endoscopic thyroidectomy: Six years of experience with the same surgeon

Background

Scarless endoscopic thyroidectomy (ET) is increasingly accepted by the growing amount of surgeons. The target of this study is to assess the efficacy and summarise the experiences of total areola approach for ET (TAAET).

Subjects and Methods

TAAET was performed on 529 patients between January 2016 and October 2021. All operated patients were divided into two groups according to the chronological order. Demographic data, perioperative data and post-operative complications were collected to assess the effectiveness of TAAET.

Results

Five hundred and twenty-eight patients were successfully treated with TAAET, while 1 case was converted to open surgery due to bleeding. The surgical approach consists of lobectomy or total thyroidectomy with or without central lymph node dissection. The post-operative pathology of 433 (81.9%) patients was diagnosed with T1 ~2N0M0. The average number of unilateral lymph node dissection was 7.72 ± 2.44 while the bilateral lymph node was 10.70 ± 3.72. In terms of complications, 38 cases had transient hoarseness, 28 cases had tetany and numbness, 3 cases had post-operative bleeding, 1 case had infection and 33 cases had subcutaneous fluid. There were statistically significant differences between the two groups with respect to transient hoarseness (P < 0.001), tetany and numbness (P = 0.005), intraoperative blood loss (P = 0.003) and operation time for malignant tumour (P < 0.001) because of the accumulation of surgical experience and the maturation of technology.

Conclusions

TAAET which conforms to the anatomical pathway of open thyroidectomy is a safe, effective and feasible technique and is highly suitable for novices.

Surgical tips and techniques to avoid complications of thyroid surgery

Objectives

Surgery of the thyroid takes place in a body part with complicated anatomy and several vital physiologic functions. Thyroidectomy is rarely associated with mortality but can be followed by significant complications, (i.e. hypoparathyroidism, hemorrhage, upper airway obstruction, laryngeal nerve injuries and thyrotoxic storm). This review aims to indicate surgical tips and techniques to sustain a low level of complications.

Content

MEDLINE database (PubMed) platform was used as a search engine and the articles related to the topic were selected using the keywords combination "thyroid surgery and complications".

Summary and Outlook

The most common complication of total thyroidectomy with an occurrence ranging between 0.5 and 65% is hypoparathyroidism. Damage to recurrent laryngeal nerves can be temporary or permanent, unilateral or bilateral; bilateral lesion is associated with severe episodes of breathlessness. Thus, intraoperative monitoring of nerve function is essential to prevent damage. Ιn addition, hematoma formation can lead to breathing difficulties due to airway obstruction; preventive hemostasis during surgery is essential. The surgeon must have a complete anatomical understanding of not only the normal anatomy of the central visceral compartment of the neck, but also the common variations of the laryngeal nerves and parathyroid glands in order to keep the complication rate at a very low level.

Mitoxantrone hydrochloride injection for tracing helps to decrease parathyroid gland resection and increase lymph node yield in thyroid cancer surgery: a randomized clinical trial

The identification and preservation of parathyroid glands (PGs) during thyroid surgery can be challenging. Many techniques have been developed to help surgeons find PGs. We have developed a novel mitoxantrone hydrochloride injection that can be used for lymphatic targeting. After local application during surgery, mitoxantrone hydrochloride injection for tracing (MHI) helps surgeons better identify and preserve PGs and helps pathologists find more lymph nodes. We conducted an open-label, multicenter, randomized clinical trial (CTR20171137) in six centers in China from 08/2017 to 12/2018. Patients with thyroid carcinoma were randomized to the MHI group or the control group. All patients received total thyroidectomy and bilateral central compartment lymph node dissection. The primary outcomes were the PG resection rate and lymph node staining rate. The full analysis set (FAS) included 461 patients, of which 228 were assigned to the MHI group, and 233 were assigned to the control group. The PG resection rates of the MHI group and the control group were 6.6% (15/228) and 26.6% (62/233), respectively, with a significant difference (P < 0.001). No PGs were stained blue with MHI. The central lymph nodes were stained blue with MHI, and the staining rate was 90.5%±12.0%. More lymph nodes were detected in the MHI group than in the control group (13.0±7.3 vs. 10.1±6.4 nodes/patient, P < 0.001). No adverse events related to MHI were observed. MHI is a safe and effective tracer that may help to preserve PGs and identify more central lymph nodes in patients with thyroid cancer.

European Expert Consensus on Practical Management of Specific Aspects of Parathyroid Disorders in Adults and in Pregnancy: Recommendations of the ESE Educational Program of Parathyroid Disorders

This European expert consensus statement provides recommendations for the diagnosis and management of primary hyperparathyroidism (PHPT), chronic hypoparathyroidism in adults (HypoPT), and parathyroid disorders in relation to pregnancy and lactation. Specified areas of interest and unmet needs identified by experts at the second ESE Educational Program of Parathyroid Disorders (PARAT) in 2019, were discussed during two virtual workshops in 2021, and subsequently developed by working groups with interest in the specified areas. PHPT is a common endocrine disease. However, its differential diagnosing to familial hypocalciuric hypercalcemia (FHH), the definition and clinical course of normocalcemic PHPT, and the optimal management of its recurrence after surgery represent areas of uncertainty requiring clarifications. HypoPT is an orphan disease characterized by low calcium concentrations due to insufficient PTH secretion, most often secondary to neck surgery. Prevention and prediction of surgical injury to the parathyroid glands are essential to limit the disease-related burden. Long-term treatment modalities including the place for PTH replacement therapy and the optimal biochemical monitoring and imaging surveillance for complications to treatment in chronic HypoPT, need to be refined. The physiological changes in calcium metabolism occurring during pregnancy and lactation modify the clinical presentation and management of parathyroid disorders in these periods of life. Modern interdisciplinary approaches to PHPT and HypoPT in pregnant and lactating women and their newborns children are proposed. The recommendations on clinical management presented here will serve as background for further educational material aimed for a broader clinical audience, and were developed with focus on endocrinologists in training.

Complications of Trans-oral Endoscopic Thyroidectomy Vestibular Approach: A Systematic Review

This review focuses on complications linked to trans-oral endoscopic thyroidectomy via vestibular approach (TOETVA) and aimed to elucidate the procedure's initial safety profile. According to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA), Pubmed, Embase, and the Cochrane databases were screened till May 2021. Twenty-eight articles, nine cohorts and nineteen case series, met the inclusion criteria. Procedure-related complications were analyzed, the most important being hypoparathyroidism: transient (range=0.94-22.2%), permanent (range=1.33-2.22%), and recurrent laryngeal nerve injury: transient (range=1.9-8.8%) and permanent (range=0.59-1.42%). Surgical trauma related complications, the most prevalent being seroma, emphysema, and hematoma accounted for 2.91%. Null mortality was reported. Although current evolving experience indicates that TOETVA is safe and linked to acceptable complication rates, the method needs to be compared with the gold standard of traditional thyroidectomy in the context of sufficiently numbered cohorts and ultimately randomized controlled trials.

The utility of indocyanine green (ICG) for the identification and assessment of viability of the parathyroid glands during thyroidectomy

We conducted this study to evaluate the ability of indocyanine green (ICG) and near infra-red fluorescence (NIRF) camera to aid in the identification and assessment of viability of parathyroid glands during thyroid surgery. A prospective observational study was conducted between May and October 2020 among 50 consecutive patients who underwent total thyroidectomy at a single institution. Parathyroid glands were identified under white light during thyroidectomy following which reconstituted ICG was injected through a peripheral vein and the location of parathyroid glands was confirmed. The perfusion to the parathyroid gland was assessed by documenting the fluorescence intensity score (FIS) and the parathyroid angiogram score (PAS). There was no difference in the number of parathyroid glands seen on visual inspection 147 (73.5%) when compared to under NIRF camera, 146 (73%). Though the rate of postoperative hypoparathyroidism was lower in the cohort with FIS 3 (14.2%) compared to score 2 and 1 (28.5% and 100%, respectively), this was not significant (p = 0.35). A significant correlation was noted between a delayed flow on PAS and the development of post-thyroidectomy hypoparathyroidism (p = 0.01). PAS had a sensitivity of 100%, specificity of 88.6%, NPV of 100% and PPV of 55.6% to predict the development of post-thyroidectomy hypoparathyroidism. In this study, there was no additional benefit of ICG and NIRF camera in the identification of parathyroid glands. However, ICG angiogram seems to be a good adjunct for the intraoperative assessment of the viability of the parathyroid glands and accurately predicts the development of postoperative hypoparathyroidism.

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

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

The Effect of Parathyroid Gland Autotransplantation on Hypoparathyroidism After Thyroid Surgery for Papillary Thyroid Carcinoma

Purpose

There are some controversies over the relationship between parathyroid gland autotransplantation and permanent hypoparathyroidism. This study aimed to explore the relationship between parathyroid gland autotransplantation and postoperative hypoparathyroidism.

Patients and Methods

We performed a retrospective analysis of patients who underwent initial thyroid surgery for papillary thyroid carcinoma from January 2014 to December 2018. Patients were divided into 4 groups according to the number of autotransplanted parathyroid glands (group 1: 0 autotransplanted parathyroid gland, group 2: 1 autotransplanted parathyroid gland, group 3: 2 autotransplanted parathyroid glands, group 4: 3 autotransplanted parathyroid glands). Clinical data were analyzed among the four groups.

Results

The more parathyroid glands were transplanted, the higher the incidence of immediate hypoparathyroidism was (group 1: 32.9%, group 2: 52.9%, group 3: 65.8%, group 4: 82.4%; P_{group 1 vs group 2} < 0.001, P_{group 2 vs group 3} = 0.012, P_{group 3 vs group 4} = 0.17). Parathyroid gland autotransplantation did not affect the incidence of permanent hypoparathyroidism (group 1: 1.4%, group 2: 1.3%, group 3: 0.9%, group 4: 0%; P_{group 1 vs group 2} > 0.99, P_{group 2 vs group 3} > 0.99, P_{group 3 vs group 4} > 0.99).

Conclusion

The number of autotransplanted parathyroid glands was positively associated with the incidence of postoperative immediate hypoparathyroidism. Parathyroid gland autotransplantation was not associated with permanent hypoparathyroidism.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Health-related quality of life after transoral robotic thyroidectomy in papillary thyroid carcinoma

BACKGROUND

Health-related quality of life after transoral robotic thyroidectomy has not been evaluated thoroughly. The purpose of this study was to compare health-related quality of life after transoral robotic thyroidectomy and after conventional thyroidectomy.

METHODS

This study is a prospective, cross-sectional, and observational study of 114 patients who underwent transoral robotic thyroidectomy (57 patients) or conventional transcervical thyroidectomy (57 patients) for the treatment of papillary carcinoma. We used 2 questionnaires: the University of Washington Quality of Life questionnaire for head and neck cancer and the thyroid cancer-specific Quality of Life questionnaire (Thyroid Version). The survey was performed preoperatively, and 3 months and 1 year after thyroidectomy.

RESULTS

Mean scores for neck appearance were higher after surgery in the transoral robotic thyroidectomy group than the conventional group at both 3 months and 1 year. Anxiety was significantly improved after surgery in both groups. Total scores for health-related quality of life after surgery were similar in both groups. Health-related quality of life and overall quality of life over the previous 7 days as measured by the University of Washington Quality of Life questionnaire were significantly better at 1 year than in the preoperative period in both groups. Before surgery, patients in the both groups regarded anxiety and mood as the most important aspects of health-related quality of life. After surgery, patients in the transoral robotic thyroidectomy group identified anxiety, mood, and speech as the most significant issues, while patients in the conventional group selected anxiety, mood, and neck appearance.

CONCLUSION

Quality of life related to neck appearance is higher after transoral robotic thyroidectomy than after transcervical thyroidectomy. However, total scores for health-related quality of life did not differ in the 2 groups after surgery.

Relationship between the extent of central node dissection and parathyroid function preservation in thyroid cancer surgery

Background

The risk and effect of hypocalcemia following surgery of different magnitudes remains unclear. Thus, we assessed whether different extents of central lymph node dissection (CLND) and status of preserved parathyroid glands can influence parathyroid function in differentiated thyroid carcinoma (DTC) patients with initial surgical resection.

Methods

Participants were categorized into 6 groups based on the extent of the surgical procedures, number of parathyroid glands preserved in situ, and parathyroid autotransplantation. The frequencies of hypocalcemia, serum calcium (Ca) levels, and parathyroid hormone (PTH) levels among the different groups were analyzed.

Results

The prevalence of hypocalcemia, number and status of parathyroid glands preserved in situ, and parathyroid autotransplantation were inversely related to extensive CLND (r=-0.18; P<0.05). The decrease of serum Ca and PTH was most severe on postoperative days (POD) 1-7. The incidence of hypocalcemia was higher in Group C than in Group B and A (P<0.05). The average postoperative serum Ca and PTH levels in Group C were significantly lower than group A on POD 1-7 (P<0.05). The incidence of hypocalcemia was obviously increased in Group D compared to Groups E and F (P<0.05). The mean serum Ca and PTH levels in Group D were significantly lower than in Group F (P<0.05), and the same results could be observed between Groups D and E (P<0.05). However, through parathyroid autotransplantation, there was no significant difference that could be found between Groups E and F on POD 1-7 (P>0.05).

Conclusions

With the expansion of CLND scope, postoperative parathyroid function will be affected, increasing the risk of postoperative hypocalcemia. When at least 1-2 parathyroid glands were reserved in situ plus at least 1 parathyroid gland autotransplantation, there was little effect on postoperative parathyroid function.

Wireless parathyroid detection device using autofluorescence and smart glasses: A preliminary study

BACKGROUND

Autofluorescence imaging technology has been utilized for preserving or identifying parathyroid glands (PTGs) during thyroid surgery. We developed a wireless PTGs detection device linked with smart glasses that allows for real-time video recording and screen switching according to the light source.

OBJECTIVE

This study aimed to confirm the feasibility of the device and whether it would help preserve the PTG during the surgery.

METHODS

This prospective study was conducted in 30 patients with 66 PTGs. The device's agreement with the physician's judgment was evaluated, and we determined how many PTGs were preserved from thyroidectomy.

RESULTS

The positive agreement rate for PTGs detection between the surgeon and device was 70.9%. Inadvertent parathyroidectomy was identified in surgical specimens of 6 patients (20%). No PTG was removed when it was confirmed by the device (0/39). Of the 27 glands not detected by the device, there was inadvertent removal of 6 PTGs.

CONCLUSIONS

PTGs can be preserved successfully when the detection of them by the device is consistent with the surgeon's discretion. A large-scale controlled study is necessary to demonstrate the practical effect of this device on hypoparathyroidism after thyroidectomy.

Application of carbon nanoparticles combined with intraoperative neuromonitoring in papillary thyroid microcarcinoma surgery

PURPOSES

To improve the lymph node dissection as well as protect parathyroid gland and recurrent laryngeal nerve, the carbon nanoparticles and intraoperative neuromonitoring were applied in papillary thyroid microcarcinoma surgery.

METHODS

Carbon nanoparticles and intraoperative neuromonitoring were used in the experimental group, whereas the control group were not. Routine pathological examination was performed.

RESULTS

The lymph nodes dissected was significantly higher in the experimental group, but the metastatic lymph nodes were not. The number of mistakenly dissected parathyroid gland and postoperative hypoparathyroidism were 3 and 13 in the experimental group respectively, significantly less than 10 and 25 in the control group. The incidences of overall, transient and persistent recurrent laryngeal nerve palsy in the experimental group were 5.5%, 5.5% and 0% respectively, whereas in the control group were 8.6%, 6.9% and 1.7%.

CONCLUSIONS

Carbon nanoparticles can improve lymph node dissection in papillary thyroid microcarcinoma surgery, and the combination of carbon nanoparticles with intraoperative neuromonitoring can reduce surgical complications and improve patient quality of life.

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

Background

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

Methods

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

Results

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

Conclusions

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Risk factors and effects of hypocalcemia prior to discharge following thyroidectomy

PURPOSE

To find patient and surgical characteristics associated with hypocalcemia prior to discharge (HPTD) in thyroidectomy patients.

MATERIALS AND METHODS

In a retrospective analysis of the 2016-2017 National Surgical Quality Improvement Program, eligible total thyroidectomy patients were stratified into cohorts based on development of HPTD. We identified demographic and surgical risk factors for the development of hypocalcemia via binary logistic regression and identified the negative sequelae of HPTD utilizing univariate and multivariate methods.

RESULTS

We identified a total of 6519 patients who underwent total thyroidectomy, of which 450 (6.9%) had HPTD. Predictors associated with an increased incidence of HPTD included female sex (OR: 1.737 [95% CI: 1.319-2.288]; p < .001), increased operative time (OR: 1.003 [1.002-1.004]; p < .001), and central neck dissection (OR: 1.484 [1.190-1.850]; p < .001). However, factors that decreased incidence of HPTD included increased age, obesity (OR: 0.648 [0.501-0.837]; p = .001), and the use of vessel sealant devices (VSD) (OR: 0.650 [0.527-0.803]; p < .001). Multivariate analysis further revealed that HPTD independently led to an increased hospitalization length after surgery (B: 0.708 [0.607-0.809]; p < .001) and an increased 30-day readmission rate (OR: 2.429 [1.594-3.704]; p < .001).

CONCLUSION

Obesity, increased age, and intra-operative VSD use were significantly associated with decreased rates of HPTD after total thyroidectomy. Female sex, longer operations, and central neck dissections were associated with HPTD. Delineating risk factors and protective factors for HPTD in total thyroidectomy patients is important as patients with HPTD were found to be at a significantly higher risk for longer post-operative stays, increased odds of 30-day readmission, and increased hypocalcemia-related event.

Intraoperative neuromonitoring of the RLNs during TOETVA procedures

Transoral endoscopic thyroidectomy by vestibular approach (TOETVA) is now being performed in increasing frequency and getting more and more attention. TOETVA is carried out through three incisions in the oral vestibular area. Thyroidectomy is performed endoscopically using conventional laparoscopic instruments, an energy based device and neuromonitoring instruments. Intraoperative neuromonitoring is one of the tools of utmost importance, used for navigation and confirmation of the functional integrity of the recurrent nerve during TOETVA. The aim of this study is to give information about the standards and technique of intraoperative neuromonitoring of the recurrent laryngeal nerves during TOETVA procedures. TOETVA is a safe technique with no visible scarring and hence resulting in an excellent cosmetic effect. We believe that neuromonitoring of the recurrent laryngeal nerves also minimizes the risk of nerve damage and is an essential safety component in this technique.

Safety of central compartment neck dissection for transoral endoscopic thyroid surgery in papillary thyroid carcinoma

Background

Remote access and endoscopic thyroid surgery has been gaining popularity because it allows patients to avoid a visible scar in the neck. There is limited data on transoral endoscopic thyroidectomy when it relates to patients with papillary thyroid carcinoma. We aim to evaluate the safety of ipsilateral central compartment dissection for patients who undergo transoral thyroidectomy (thyroidectomy vestibular approach–compartment lymph node dissection).

Patients and Methods

A total of 80 patients who underwent thyroidectomy vestibular approach–compartment lymph node dissection for papillary thyroid carcinoma from June 2015 to September 2016 were identified. Over the same period, a matched cohort of 80 patients who underwent open thyroidectomy with routine ipsilateral central compartment dissection was also identified (Open-compartment lymph node dissection). The two groups were analyzed in terms of patient characteristics, perioperative clinical results and post-operative outcomes.

Results

All patients were female with a mean age of 32-year. There was no difference in mean maximum tumor size and number of lymph nodes dissected. Moreover, there was no difference in average positive lymph nodes between thyroidectomy vestibular approach–compartment lymph node dissection and Open-compartment lymph node dissection (1.48 vs 1.08, P = 0.647). Operative time was longer in the thyroidectomy vestibular approach–compartment lymph node dissection group (193 vs 102 min, P &lt; 0.001). Thyroidectomy specific complications were similar with rates of temporary recurrent laryngeal nerve palsy of 6.3 vs 8.8% and temporary hypocalcemia rates of 2.5 vs 5% in the thyroidectomy vestibular approach–compartment lymph node dissection and Open-compartment lymph node dissection groups, respectively.

Conclusions

Thyroidectomy vestibular approach–compartment lymph node dissection is a feasible and safe option for select patients with papillary thyroid carcinoma who require central node dissection compared with Open-compartment lymph node dissection, and can be a viable alternative for patients wishing to avoid a visible scar.

Evaluation of Parathyroid Glands with Indocyanine Green Fluorescence Angiography After Thyroidectomy

BACKGROUND

Indocyanine green fluorescence angiography (ICGA) is a new adjunct that has been used in surgical procedures to assess blood flow. This study evaluated the utility of ICGA compared to visual inspection to predict parathyroid function, guide autotransplantation and potentially decrease permanent hypoparathyroidism.

METHODS

This was a retrospective study of patients who underwent total or near-total thyroidectomy (T-NT) between January 2015 and March 2018. Patients with preoperative hyperparathyroidism and those undergoing reoperation were excluded. Patients who had ICGA were compared to T-NT patients without ICGA. Data were analyzed to assess the frequency of autotransplantation and incidence of hypoparathyroidism between groups.

RESULTS

In total, 210 patients underwent T-NT: 86 with ICGA and 124 without. Autotransplantation was more common in the ICGA group at 36% compared to 12% in the control (p = 0.0001). There was no correlation with at least one normal parathyroid gland on ICGA and postoperative PTH levels (p = 0.75). There was a difference in having normal postoperative PTH when there were at least two normal parathyroid glands (n = 50) compared to patients with less than two normal ICGA glands (n = 36, p = 0.044). Visual assessment and ICGA assessment of vascularity were in agreement, 245/281 (87%). There were 19 glands (6.8%) that would have undergone autotransplant based on visual inspection that had adequate blood supply on ICGA. Transient hypoparathyroidism was present in 45 out of 124 controls (36%) and 32 out of 86 (37%) in the ICG group.

CONCLUSIONS

ICGA is a novel technique that may improve the assessment of parathyroid gland blood supply compared to visual inspection. ICGA can guide more appropriate autotransplantation without compromising postoperative parathyroid function. At least two vascularized glands on ICGA may predict postoperative parathyroid gland function.

Hypoparathyroidism After Total Thyroidectomy: Importance of the Intraoperative Management of the Parathyroid Glands

BACKGROUND

Total thyroidectomy is the most common surgical procedure for the treatment of thyroid diseases. Postoperative hypocalcemia/hypoparathyroidism is the most frequent complication after total thyroidectomy. The aim of this study was to evaluate the rate of postoperative hypocalcemia and permanent hypoparathyroidism after total thyroidectomy in order to identify potential risk factors and to evaluate the impact of parathyroid autotransplantation.

PATIENTS AND METHODS

We performed a retrospective analysis of 1018 patients who underwent total thyroidectomy at our institution between 2000 and 2016. Medical records were reviewed to analyze patient features, clinical presentation, management and postoperative complications. Descriptive and inferential statistics were employed based on the natural scaling of each included variable. Statistical significance was set at p ≤ 0.05.

RESULTS

Mean ± SD age was 46.79 ± 15.9 years; 112 (11.7%) were males and 844 (88.3%) females. A total of 642 (67.2%) patients underwent surgery for malignant disease. The rate of postoperative hypocalcemia, transient, protracted and permanent hypoparathyroidism was 32.8%, 14.43%, 18.4% and 3.9%, respectively. Permanent hypoparathyroidism was significantly associated with the number of parathyroid glands remaining in situ (4 glands: 2.5%, 3 glands: 3.8%, 1-2 glands: 13.3%; p ˂ 0.0001) [OR for 1-2 glands in situ = 5.32, CI 95% 2.61-10.82]. Other risk factors related to permanent hypoparathyroidism were obesity (OR 3.56, CI 95% 1.79-7.07), concomitant level VI lymph node dissection (OR 3.04, CI 95% 1.46-6.37) and incidental parathyroidectomy without autotransplantation (OR 3.6, CI 95% 1.85-7.02).

CONCLUSIONS

Identification and in situ preservation of at least three parathyroid glands were associated with a lower rate of postoperative hypocalcemia (30.4%) and permanent postoperative hypoparathyroidism (2.79%).

Factors contributing to unintentional parathyroidectomy during thyroid surgery

Unintentional parathyroidectomy during thyroid surgery has an incidence ranging between 1% and 31% across institutions. Many studies have identified malignancy and central neck dissection as risk factors for losing parathyroid glands, but few studies have evaluated the impact of other factors such as lymphocytic thyroiditis, hyperthyroidism, or concomitant primary hyperparathyroidism. The purpose of this study was to investigate which factors contribute to parathyroid loss during thyroid surgery. Charts of 269 patients undergoing thyroid surgery at a tertiary care medical center from 2010 to 2013 were retrospectively reviewed. Sixty-six patients (24.5%) experienced unintentional parathyroidectomy. Bivariate analysis showed no significant differences in patient characteristics. Patients with unintentional parathyroid removal had a significantly smaller largest thyroid nodule size (P = 0.002), higher rate of central neck dissection (30.3% vs 7.9%, P < 0.0001), and higher rate of malignancy (50% vs 36.0%, P = 0.04). Multivariable analysis showed that the strongest risk factor for unintentional parathyroidectomy was central neck dissection (P = 0.0008; odds ratio 4.72, confidence interval 1.91-11.71). In conclusion, central neck dissection for thyroid malignancy is the strongest risk factor for unintentional thyroidectomy. The presence of concomitant primary hyperparathyroidism, lymphocytic thyroiditis, or hyperthyroidism did not appear to increase the risk of unintentional parathyroidectomy.

The Learning Curve for Surgeons Regarding Endoscopic Thyroidectomy via the Oral-vestibular Approach

BACKGROUND

For selected patients, endoscopic thyroidectomy via the oral-vestibular approach (ETOVA) can be used to achieve a very good esthetic effect. This study aimed to assess the learning curve for ETOVA and identify improvements.

PATIENTS AND METHODS

This retrospective study evaluated the outcomes of 101 patients who underwent ETOVA by surgeons A and B. The patients were classified according to whether they had undergone surgery during the primary or advanced stage of the learning curve, respectively. Proficiency with the procedure in various types of cases and the operation time, operative blood loss, hospital stay length, and postoperative complications were analyzed.

RESULTS

In total, 56 and 45 patients were treated by surgeons A and B, respectively. For both surgeons, the operation times decreased considerably after 20 cases. Statistically significant differences with respect to stage were observed in terms of operation time (P<0.05) and drainage tube reservation (P<0.05). By contrast, significant differences were not observed between stages in terms of operative blood loss (P>0.05) or postoperative hospital stay length (P>0.05). The total postoperative complication rate was low and comparable with that of open surgery.

CONCLUSIONS

The specific learning curve identified for ETOVA suggests that surgeons with sufficient endoscopic surgery experience could achieve a stable proficiency after ∼20 cases. A standardized training program and exposure to more cases would reduce the learning curve.

Risk factors and outcomes of incidental parathyroidectomy in thyroidectomy: A systematic review and meta-analysis

Introduction

Postoperative hypocalcemia is the most common complication of thyroidectomy. Incidental parathyroidectomy (IP) was thought to be associated with postoperative hypocalcemia. However, according to previous studies, the risk factors and clinical outcomes of IP remain controversial.

Methods

Eligible studies were searched in databases including PubMed, Web of Science, and EMBASE from January 1990 to September 2017. Articles focusing on the relationship between IP and postoperative hypocalcemia were included. The risk of publication bias was assessed using Begg’s test and Egger’s regression asymmetry test. Pooled analysis was performed to evaluate the effect of IP on postoperative hypocalcemia and related risk factors. Sensitivity analysis was also conducted to test the stability of our results. The effects of hypocalcemia type, permanent definition, IP incidence, total thyroidectomy, and malignancy operation were also examined using a further subgroup analysis.

Results

Thirty-five studies were finally included in the analysis after an exhaustive literature review. Pathology data demonstrate that incidental parathyroidectomy occurred in various locations: intrathyroidal (2.2–50.0%), intracapsular (16.7–40.0%) and extracapsular (15.7–81.1%) regions. Overall, the analysis found that malignancy (RR = 1.60, 95% CI: 1.27 to 2.02; p< 0.0001), central neck dissection (RR = 2.35, 95% CI: 1.47 to 3.75; p = 0.0004), total thyroidectomy (RR = 1.42, 95% CI: 1.20 to 1.67; p< 0.0001) and reoperation (RR = 1.81, 95% CI: 1.20 to 2.75; p = 0.005) were significant risk factors of IP in thyroid surgery. There was an obvious effect of IP on temporary/permanent (RR = 1.59, 95% CI: 1.37 to 1.84; p< 0.0001) and permanent (RD = 0.0220, 95% CI: 0.0069 to 0.0370; p = 0.0042) postoperative hypocalcemia. Sensitivity analysis showed that these results were robust. The subgroup analysis found that IP played a significant role in both biochemical and clinical hypocalcemia in thyroidectomy (p < 0.0001 and p = 0.0003, separately). The association of IP and permanent hypocalcemia using different definitions (6 months or more than 12 months) was also confirmed by the analysis. IP increased the incidence of temporary/permanent and permanent hypocalcemia for cases undergoing total thyroidectomy (40.4% vs 24.8% and 5.8% vs 1.4%, respectively). Thyroidectomy with IP was associated with more permanent hypocalcemia (RR = 3.10, 95% CI: 2.01 to 4.78; p< 0.0001) in malignant cases but was not associated with temporary/permanent hypocalcemia.

Conclusions

Malignancy, central neck dissection, total thyroidectomy and reoperation were found to be significant risk factors of IP. IP increases the risk of postoperative hypocalcemia after thyroidectomy. We recommend a more meticulous intraoperative identification of parathyroid gland in thyroidectomy to reduce IP, particularly for total thyroidectomy and malignancy cases.

A new classification of parathyroid glands to evaluate in situ preservation or autotransplantation during thyroid surgery

The indication for autotransplantation of parathyroid glands is still controversial. A new classification of parathyroid glands based on the positional relationship among parathyroid glands, thyroid gland and thymus was created to decide in situ preservation or autotransplantation during thyroid surgery.A retrospective study included patients with papillary thyroid cancer who underwent total thyroidectomy with bilateral central lymph node dissection between November 2014 and November 2016. According to the application of the new classification (December 2015-November 2016) or traditional method (preservation of all functional parathyroid glands in situ, November 2014-November 2015), the patients were divided into new classification and traditional groups.The traditional method was utilized in 288 patients who underwent surgery during the first half of the study, while the new classification was applied to 249 patients during the latter half of the study. The incidence of transient hypoparathyroidism was 43.0% (107/249) in new classification group and 35.8% (103/288) in the traditional group, respectively (P = .093). The corresponding incidence of permanent hypoparathyroidism was 0.4% (1/249) and 4.5% (13/288) (P = .002).The new classification of parathyroid glands potentially reflects the difficulty of preservation and helps to make a reasonable decision on preservation or autotransplantation of a parathyroid gland, which may minimize the incidence of permanent hypoparathyroidism.

The function of carbon nanoparticles to improve lymph node dissection and identification of parathyroid glands during thyroid reoperation for carcinoma

To evaluate the function of carbon nanoparticles during the thyroid reoperation for carcinoma, we conducted this study by retrospectively analyzing the data of patients who underwent at least completion thyroidectomy with bilateral central lymph nodes dissection for thyroid carcinoma from January 2009 to June 2016. The clinicopathologic characteristics and surgical details were compared between the patient who accepted intraoperative carbon nanoparticles injection and those who accepted nothing injection during the surgery. The main monitoring indicators were the number of dissected lymph nodes and metastatic lymph nodes in central zone, the number of identified parathyroid glands and autoplastic parathyroid glands and unintentionally resected parathyroid glands. A total of 69 patients were enrolled into the carbon nanoparticles group and 128 patients were enrolled into the control group.The average number of lymph nodes harvested in the central zone was higher in the carbon nanoparticles group than that in the control group (11.2 ± 5.7 vs 7.7 ± 4.0, P < .001), so was the average number of metastatic lymph nodes (4.5 ± 4.5 vs 2.7 ± 2.9, P = .004). The average number of identified parathyroid gland was greater in the carbon nanoparticles group than that in the control group (2.4 ± 1.2 vs 1.6 ± 1.1, P < .001). The average number of autoplastic parathyroid gland was comparable between the 2 groups (0.6 ± 0.6 vs 0.4 ± 0.7, P = .052). But the average number of unintentionally resected parathyroid gland was less in the carbon nanoparticles group than that in the control group (0.1 ± 0.2 vs 0.2 ± 0.4, P = .007). Carbon nanoparticles can improve lymph nodes dissection and identification of parathyroid gland during thyroid reoperation for carcinoma.

Does the number of parathyroid glands autotransplanted affect the incidence of hypoparathyroidism and recovery of parathyroid function?

BACKGROUND

The relationship between the number of parathyroid glands autotransplanted and hypoparathyroidism as well as recovery of parathyroid function is not understood fully. The aim was to ascertain whether the number of autotransplanted glands affected the incidence of hypoparathyroidism and recovery of parathyroid function in long-term follow-up after thyroidectomy.

METHODS

A retrospective cohort study included all patients with papillary thyroid carcinoma who underwent first-time total thyroidectomy with central neck dissection between June 2012 and June 2015. The patients were divided into 4 groups (0, 1, 2, and 3) on the basis of the number of parathyroid glands autotransplanted.

RESULTS

Of the 766 patients, 283 (36.9%) had no gland autotransplanted, and 373 (48.7%), 97 (12.7%), and 13 (1.7%) had 1, 2, and 3 glands autotransplanted, respectively. More lymph nodes and more metastatic ones in the central compartment were retrieved in groups 2 and 3 (P < .05). With increasing number of autotransplanted glands, the incidence of transient hypoparathyroidism was 26.1%, 36.2%, 52.6%, and 84.6% (P < .05), and the incidence of permanent hypoparathyroidism was 1.8%, 1.1%, 1.0%, and 0% (P > .05). The recovery rates of serum parathyroid hormone concentration were 84.7%, 82.2%, 82.0%, and 79.2% after 2-year follow-up (P > .05).

CONCLUSION

Autotransplantation is an effective strategy for restoration of parathyroid function. Transient hypoparathyroidism is positively correlated to the number of autotransplanted parathyroid glands during total thyroidectomy with central neck dissection. There is no increase in permanent hypoparathyroidism in patients with a higher number of autotransplanted glands, despite more extensive lymph node disease. (Surgery 2018;161:XXX-XXX.).

Effect of autotransplantation of a parathyroid gland on hypoparathyroidism after total thyroidectomy

BACKGROUND

The effect of parathyroid autotransplantation on hypoparathyroidism is not fully understood. The purpose of the study was to determine the effect of autotransplantation of a parathyroid gland on the incidence of hypoparathyroidism and recovery of parathyroid function at 6 months after total thyroidectomy with central neck dissection for papillary thyroid carcinoma.

METHODS

All patients with autotransplantation of a parathyroid gland (no inadvertent parathyroidectomy) (group A), in situ preservation of all parathyroid glands (no autotransplantation and inadvertent parathyroidectomy) (group B) or inadvertent removal of a parathyroid gland (no autotransplantation) (group C) who underwent first-time total thyroidectomy with central neck dissection for papillary thyroid carcinoma between January 2013 and June 2016 were included retrospectively.

RESULTS

Of the 702 patients, 383, 297 and 22 were respectively included in the groups A, B and C. The overall rates of transient and permanent hypoparathyroidism were 37.6% and 1.0%. The incidence of transient hypoparathyroidism was 43.9, 29.0 and 45.5% (A vs B, P = 0.000; A vs C, P = 1.000), and the incidence of permanent hypoparathyroidism was 1.0, 0.7 and 4.5% (P > 0.05). The recovery rates of serum parathyroid hormone levels were 71.4, 72.2 and 66.0% at 6-month follow-up (P > 0.05).

CONCLUSION

Autotransplantation of a parathyroid gland does not affect the incidence of permanent hypoparathyroidism, but increases the risk of transient hypoparathyroidism when the rest of parathyroid glands are preserved in situ. At least 2 parathyroid glands should be preserved during total thyroidectomy with central neck dissection to prevent permanent hypoparathyroidism.

Diagnosis and treatment of hypoparathyroidism: a position statement from the Brazilian Society of Endocrinology and Metabolism

Objective To present an update on the diagnosis and treatment of hypoparathyroidism based on the most recent scientific evidence. Materials and methods The Department of Bone and Mineral Metabolism of the Sociedade Brasileira de Endocrinologia e Metabologia (SBEM; Brazilian Society of Endocrinology and Metabolism) was invited to prepare a document following the rules set by the Guidelines Program of the Associação Médica Brasileira (AMB; Brazilian Medical Association). Relevant papers were retrieved from the databases MEDLINE/PubMed, LILACS, and SciELO, and the evidence derived from each article was classified into recommendation levels according to scientific strength and study type. Conclusion An update on the recent scientific literature addressing hypoparathyroidism is presented to serve as a basis for the diagnosis and treatment of this condition in Brazil.

In Situ Preservation Fraction of Parathyroid Gland in Thyroidectomy: A Cohort Retrospective Study

BACKGROUND AND OBJECTIVES

Parathyroid failure is the most common symptom after thyroidectomy. To prevent it, a gland was preserved in situ or an ischemic one was autotransplanted. This study explored the relationship between in situ preservation of the parathyroid gland and gland failure.

METHODS

Consecutive patients who underwent initial total thyroidectomy were enrolled retrospectively in a prospectively maintained database. Patients were divided into groups by parathyroid gland remaining in situ fraction (PGRIF) (PGRIF = number of in situ glands/(total number of identified glands - number of glands in specimen). Patients were graded by tertiles and followed at least one year after surgery.

RESULTS

559 patients were included. PGRIF is significantly inversely associated with transient hypoparathyroidism, protracted hypoparathyroidism, and postoperative hypocalcemia. PGRIF was identified as an independent risk factor for transient hypoparathyroidism, protracted hypoparathyroidism, and postoperative hypocalcemia (OR = 0.177, 0.190, and 0.330, resp.). Autotransplantation of parathyroid gland would not affect the calcium level in the long term.

CONCLUSION

In situ preservation of parathyroid gland is crucial for parathyroid function. Less preserved is the independent risk factor for postoperative hypoparathyroidism and hypocalcemia, resulting in a worse function of parathyroid gland in the long term.

Transoral endoscopic thyroidectomy vestibular approach (TOETVA): indications, techniques and results

INTRODUCTION

The Transoral Neck Surgery (TONS) Study Group was established at the 1st International Thyroid NOTES Conference in February 2016 with the intention of standardizing and refining thyroid NOTES techniques, including both transoral endoscopic and robotic thyroidectomy approaches. Herein, the authors report the modification of indications, preparation, and step-by-step explanations for operative techniques, as well as results and postoperative care for transoral endoscopic thyroidectomy vestibular approach (TOETVA).

METHODS

Between February 2015 and December 2015, a total of 200 patients comprising 8 males (4%) and 192 females (96%) underwent TOETVA using 3 laparoscopic ports inserted at the oral vestibule. Of these patients, 111 presented with single thyroid nodules (55.5%), while 66 patients had multinodular goiters (33%), 12 had Graves' disease (6%) and 11 had papillary microcarcinoma (5.5%). The CO₂ insufflation pressure was maintained at 6 mmHg. Each surgery was performed using laparoscopic instruments and ultrasonic devices.

RESULTS

TOETVA was performed on 200 consecutive patients. No conversion to conventional open surgery was necessary. Average tumor size was 4.1 ± 1.78 cm (1-10 cm). Median operative time was 97 ± 40.5 min (45-300 min). Median blood loss was 30 ± 46.25 mL (6-300 mL). Mean visual analog scale measurements were 2.41 ± 2.04 (2-7), 1.17 ± 1.4 (0-5), and 0.47 ± 0.83 (0-3) on the first, second, and third days, respectively. Temporary hoarseness and hypoparathyroidism occurred in 8 patients (4%) and 35 patients (17.5%), respectively. No permanent hoarseness or hypoparathyroidism occurred. Mental nerve injury occurred in 3 patients (1.5%). One patient (0.5%) developed a post-operative hematoma that required open surgery. No infection was identified.

CONCLUSION

TOETVA was shown to be safe and feasible with a reasonable surgical duration and minimal pain scores. This approach shows promise for those patients who are motivated to avoid a neck scar.

Factors affecting operative time in robotic thyroidectomy

BACKGROUND

The purpose of this study was to evaluate factors related to operative time in robotic thyroidectomy.

METHODS

We retrospectively analyzed 240 patients who underwent robotic thyroidectomy. The total thyroidectomy cases and lobectomy cases were both categorized into those with long operative times (LOTs; upper 25% of cases) and those with short operative times (SOTs; lower 25%).

RESULTS

Among the total thyroidectomy cases, body mass index (BMI) ≥23 kg/m² (hazard ratio [HR] 5.34; P = .008) and bilateral central neck dissection (CND; HR 14.92; P = .028) were more frequent in the LOT group in multivariate analysis. Among the lobectomy cases, BMI ≥23 kg/m² (HR 12.92; P = .003) and unilateral CND (HR 21.38; P = .017) were the only independent risk factors for prolonged operative time.

CONCLUSION

Body habitus and clinical nodal status in the central compartment should be considered in deciding the indications for robotic thyroidectomy.

To identify or not to identify parathyroid glands during total thyroidectomy

Hypoparathyroidism is one of the most common complications after total thyroidectomy and may impose a significant burden to both the patient and clinician. The extent of thyroid resection, surgical techniques, concomitant central neck dissection, parathyroid gland (PG) autotransplantation and inadvertent parathyroidectomy have long been some of the risk factors for postoperative hypoparathyroidism. Although routine identification of PGs has traditionally been advocated by surgeons, recent evidence has suggested that perhaps identifying fewer number of in situ PGs during surgery (i.e., selective identification) may further lower the risk of hypoparathyroidism. One explanation is that visual identification may often lead to subtle damages to the nearby blood supply of the in situ PGs and that may increase the risk of hypoparathyroidism. However, it is worth highlighting the current literature supporting either approach (i.e., routine vs. selective) remains scarce and because of the significant differences in study design, inclusions, definitions and management protocol between studies, a pooled analysis on this important but controversial topic remains an impossible task. Furthermore, it is worth nothing that identification of PGs does not equal safe preservation, as some studies demonstrated that it is not the number of PGs identified, but the number of PG preserved in situ that matters. Therefore a non-invasive, objective and reliable way to localize PGs and assess their viability intra-operatively is warranted. In this aspect, modern technology such as the indocyanine green (ICG) as near-infrared fluorescent dye for real-time in situ PG perfusion monitoring may have a potential role in the future.

The PGRIS and parathyroid splinting concepts for the analysis and prognosis of protracted hypoparathyroidism

Most patients with hypocalcemia after total thyroidectomy will recover the parathyroid function in a few weeks, but some 20-30% of them will still be in the need for replacement therapy one month after surgery and about 5-10% of those will develop permanent hypoparathyroidism. Although postoperative hypocalcemia has been related to several demographic and metabolic causes, parathyroid hormone (PTH) decline, resulting from autotransplantation, inadvertent excision or devascularization of the parathyroid glands, is the common final pathway. The number of parathyroid glands remaining in situ (PGRIS) is a key variable to understand the pathogenesis of protracted hypoparathyroidism and the chances for restoration of the parathyroid function. Normal-high serum calcium concentration, probably achieved by a more intensive medical treatment at the time of hospital discharge, has been identified as an independent variable favoring recovery of the parathyroid function. This we refer to as parathyroid splinting, a hypothesis holding that putting the injured parathyroid parenchyma at rest after thyroidectomy may improve long-term outcome of protracted hypoparathyroidism.

The use of ICG enhanced fluorescence for the evaluation of parathyroid gland preservation

Indocyanine green (ICG) enhanced fluorescence imaging is recent innovation as the "real-time intraoperative imaging" technique. Many clinical studies have been reported in the literature which use different devices and techniques that employ various doses and usages of ICG as a non-specific contrast agent. Several groups have performed studies in endocrine surgery, especially with regards to parathyroid-related outcomes after thyroid and parathyroid surgery. However, there is no consensus on the technical details that should be applied. With this study, we aimed to review the current literature on potential use of intraoperative ICG angiography for evaluating parathyroid gland (PTG) preservation.

Evaluation of clinical significance and risk factors of incidental parathyroidectomy due to thyroidectomy: A single-center retrospective clinical study

We assessed the clinical significance and risk factors of incidental parathyroidectomy during total thyroidectomy with or without central neck dissection or subtotal thyroidectomy.Retrospective analysis of clinical and pathological features of 548 consecutive thyroidectomy cases was compared by grouping into inadvertent resection (IR, n = 86) with IR of parathyroid glands, non-IR (n = 462) without, and then into postoperative hypoparathyroidism (PH, n = 140) with PH and non-PH (n = 408) without.Two hundred ninety-eight patients had total thyroidectomy and 250 had subtotal thyroidectomy. IR had higher malignant disease (P < .001), total thyroidectomy (P = .016), T3 and T4 classification (P = .005), central neck dissection (P < .001), recurrent laryngeal nerve palsy (P = .003), postoperative transient hypoparathyroidism (P < .001), duration of disease prior to thyroidectomy (P < .001), and weight of excised thyroid tissue (P < .001) than non-IR.Preoperative diagnosis of malignant disease, duration of disease prior to thyroidectomy, and central neck dissection were independent risk factors for incidental parathyroidectomy. Preoperative diagnosis of malignant disease, central neck dissection, duration of disease prior to thyroidectomy, weight of excised thyroid tissue, and incidental parathyroidectomy were correlated with PH.

Risk factors of hypoparathyroidism following total thyroidectomy with central lymph node dissection

The risk factors of hypoparathyroidism after total thyroidectomy (TT) with central lymph node dissection (CND) have not been completely defined. The aim of the study was to evaluate the risk factors of hypoparathyroidism after the surgery.We retrospectively reviewed our patients who underwent TT and CND (including lateral lymph node dissection) for thyroid carcinoma between January 2013 and June 2016. According to the postoperative serum levels of parathyroid hormone within 6 months, the patients were divided into normal, transient hypoparathyroidism, and permanent hypoparathyroidism groups. The clinicopathologic characteristics and surgical details were compared among the 3 groups. The risk factors of hypoparathyroidism were investigated by univariate and multivariate analyses.Of the 903 patients, 399 (44.2%) were found to have transient hypoparathyroidism and 10 (1.1%) had permanent hypoparathyroidism. On multivariate analysis, female gender (P < .001), nonuse of carbon nanoparticles (P = .038), parathyroid autotransplantation (P < .001), accidental parathyroid resection (P = .004), and bilateral CND (BCND, P = .003) were the independent risk factors of transient hypoparathyroidism; nonuse of carbon nanoparticles (P = .041) and a tumor in the upper pole of thyroid gland (P = .031) were the independent risk factors of permanent hypoparathyroidism. Patients with transient hypoparathyroidism were more likely to develop permanent hypoparathyroidism when they had hypertension (P = .026) and a tumor in the upper pole of thyroid gland (P = .010).Precise surgical techniques and carbon nanoparticles suspension should be applied for in situ preservation of parathyroid glands (PGs) in thyroid carcinoma patients, especially in females with hypertension and a tumor in the upper pole of thyroid gland. Autotransplantation is only performed when a PG is resected inadvertently or devascularized. TT with BCND should be better performed by an experienced surgeon to reduce the incidence of hypoparathyroidism.

Clinical course of incidental parathyroidectomy: Single center experience

OBJECTIVE

Thyroidectomy is a very common surgical procedure. Regardless of surgeon experience, incidental parathyroidectomy is a complication of thyroidectomy. The aim of this study was to identify the clinical course of incidental parathyroidectomies after thyroidectomy.

METHODS

Patients who underwent thyroidectomy between January 2010 and June 2014 were evaluated retrospectively. Pathology reports were reviewed for the presence of parathyroid tissue in the thyroidectomy pathology specimens. Information regarding demographic, laboratory variables, operative details, and postoperative complications were collected.

RESULTS

Incidental parathyroidectomy was found in 178 out of 3022 patients who had thyroidectomy (5.8%). Types of surgeries performed for 178 patients were total thyroidectomy (TT) in 132(74.2%) cases, TT and central lymph node dissection(CLND) in 30 (16.9%) cases, lobectomy in seven cases (3.9%), completion thyroidectomy in five (2.8%) patients and modified cervical lymph node dissection in four (2.2%)patients. One and two parathyroid glands were accidentally removed in 152 (85.3%) and 26 (14.7%) patients, respectively. In the entire series, biochemical temporary postoperative hypocalcemia occurred in 75(42.1%) patients and permanent hypocalcemia occured in 12 (6.7%) patients with incidental parathyroidectomy. There was not a statistically significant difference regarding the occurrence of postoperative permanent hypocalcemia between the patients who had incidental parathyroidectomy of one gland and the patients with two incidental parathyroidectomies (p=0.114).

CONCLUSION

Incidental parathyroidectomy is not uncommon during thyroidectomy. No association between inadvertent parathyroidectomy and postoperative permanent hypocalcemia was found.

In situ preservation of the inferior parathyroid gland during central neck dissection for papillary thyroid carcinoma

BACKGROUND

Postoperative hypocalcaemia due to dysfunction of the parathyroid glands is the most common complication after total thyroidectomy plus central neck dissection (CND). There is a lack of surgical techniques described to help preserve the inferior parathyroid gland in situ during CND. The objective of this study was to introduce the 'TBP layer' (layer of thymus-blood vessel-inferior parathyroid gland) concept for preserving the inferior parathyroid gland in situ during CND, and to evaluate its effectiveness.

METHODS

The study group included patients with primary papillary thyroid cancer who underwent total thyroidectomy with CND using the new surgical concept between January and December 2014. The control group included sex- and age-matched patients who underwent conventional total thyroidectomy with CND between January 2012 and December 2013. The proportion of inferior parathyroid glands preserved in situ and postoperative hypoparathyroidism rates in the two groups were compared.

RESULTS

There were 181 patients in the study group and 306 in the control group. There were no significant differences between the groups in tumour size, multifocality, extrathyroidal extension, and number of harvested and metastatic central lymph nodes. The rate of inferior parathyroid gland preservation in situ was significantly improved from 37·9 to 76·3 per cent on the left side (P < 0·001), and from 52·0 to 77·9 per cent on the right side (P < 0·001), in the study group compared with the control group. The incidence of transient hypoparathyroidism decreased significantly from 35·0 to 7·2 per cent (P < 0·001).

CONCLUSION

Applying the proposed surgical concept improved the rate of inferior parathyroid gland preservation in situ and decreased the incidence of transient postoperative hypoparathyroidism.