Short and long-term impact of parathyroid autotransplantation on parathyroid function after total thyroidectomy

Primary Hyperparathyroidism: Part Two: Surgical Management

Primary hyperparathyroidism (PHPT) is caused by the overproduction of parathyroid hormone by 1 or more parathyroid glands resulting in hypercalcemia and its downstream clinical consequences. The definitive management of PHPT is surgery. Approaches to successful surgery include bilateral exploration or focused parathyroidectomy with intraoperative parathyroid hormone monitoring, which in experienced hands are both associated with a low risk of complications.

5-year Follow-up of Reimplanted Parathyroid Glands in Forearm Subcutaneous Tissue During Thyroidectomy. A Confirmation of Graft Vitality in a Large Series of Patients

INTRODUCTION

The aim of this study is to assess the outcomes of parathyroid gland reimplantation with PR-FaST technique in patients undergoing thyroid surgery, focusing on graft functionality over a 5-year follow-up period.

MATERIALS AND METHODS

We analyzed data from 131 patients who underwent parathyroid reimplantation using the PR-FaST technique during thyroid surgery due to inadvertent parathyroid removal or evident vascular damage. Postoperative evaluations included serum calcium (Ca), magnesium (Mg), and phosphorus (P) analyses on the 1st and 2nd postoperative days, at 10 days, and at 1, 3, 6 months, 1 year, and 5 years of follow-up. Additionally, the mean values of serum intact parathyroid hormone (iPTH) concentration were measured from blood samples collected from both the reimplanted arm (iPTH RA) and non-reimplanted arm (iPTH NRA) within the same period.

RESULTS

Among 131 patients, at 10 days post-surgery, only 46 patients (35.1%) out of 131 exhibited graft viability (iPTH ratio >1.5). This percentage increased to 72.8% (94 patients) after 1 month and further to 87.8% (108 patients) after 3 months post-surgery. At 1 year, 84.7% of patients showed good graft functionality. After 5 years, the percentage remained stable, with graft viability observed in 81.3% of patients. Only 91 of the initial 131 patients completed follow-up up to 5 years, with a dropout rate of 30.5 %.

CONCLUSIONS

Parathyroid reimplantation using the PR-FaST technique is a viable option for patients undergoing thyroidectomy and has been shown to be a reproducible and effective technique in most patients, with sustained graft functionality and parathyroid hormone production over a 5-year follow-up period.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Parathyroid preservation in total endoscopic thyroid surgeries via the mammary areolas approach: Real-world data from a single center

BACKGROUND

Preserving parathyroid glands in situ is crucial to avoid surgical hypoparathyroidism, but it is also one of the greatest challenges during thyroid surgery. Magnified endoscopic imaging has been proposed as a way to improve parathyroid preservation.

METHODS

2,603 consecutive patients who underwent thyroid surgery at the First People's Hospital of Zunyi from January 2018 to July 2022 were screened. 1,355 patients were eligible, including 965 endoscopic and 390 open cases. Parathyroid hormone (PTH) loss levels and severe parathyroid injury rates were compared between endoscopic and open cases. Meanwhile, factors that contribute to parathyroid injuries were assessed, including surgical extent, tumor size, carbon nanoparticle guidance, and surgical proficiency.

RESULTS

PTH loss levels were similar between endoscopic and open cases (P = 0.440). The incidence of severe parathyroid injuries was also comparable (7.8% for endoscopic vs. 6.9% for open, P = 0.592). The endoscopic group had higher rates of autologous parathyroid transplantation (39.5% vs. 24.4%, P = 0.000), while accidental parathyroidectomy rates were similar (11.4% vs. 10.8%, P = 0.739). Among patients who received the same extent of thyroid surgeries, no significant difference was found in PTH loss levels and severe parathyroid injury rates, except for a higher risk of severe parathyroid injuries in endoscopic bilateral thyroidectomy (18.52% vs. 11.52%, P = 0.033).

CONCLUSIONS

Despite the magnified endoscopic imaging facilitating the identification of parathyroid tissues, endoscopic approaches are not superior to open ones for the in-situ preservation of parathyroid glands. For a bilateral thyroidectomy, open approaches are safer for parathyroid preservation.

Preservation of parathyroid glands during thyroid and neck surgery

The parathyroid glands are situated in close proximity to the thyroid gland. They have an important endocrine function maintaining calcium and phosphate homeostasis in the body by the secretion of parathormone (PTH), which is responsible for this function. The parathyroid glands are commonly damaged during thyroid surgeries. This could lead to transient or permanent hypoparathyroidism in 30% of cases. Preservation of the parathyroid glands, is an important and integral part of thyroidectomy and other surgical interventions in the neck. The main principle underlying this is a thorough understanding of parathyroid anatomy in relation to the thyroid gland and other important structures in the area. There can also be significant variation in the anatomical location of the glands. Various techniques and methods have been described for parathyroid preservation. They include intraoperative identification utilizing indocyanine green (ICG) fluorescence, carbon nanoparticles, loupes, and microscopes. The techniques of surgery (meticulous capsular dissection), expertise, central compartment neck dissection, preoperative vitamin D deficiency, extent and type of thyroidectomy are the risk factors associated with damaged thyroids, inadvertent parathyroidectomy and subsequent hypoparathyroidism. Parathyroid Autotransplantation is a treatment option for inadvertent parathyroidectomy. Ultimately, the best way to assure normal parathyroid function is to preserve them in situ intraoperatively undamaged.

US Features of the Parathyroid Glands: An Intraoperative Surgical Specimen Study

Purpose

This study aimed to evaluate the US features of the parathyroid glands (PTGs) using surgical specimens of normal PTGs obtained during thyroid surgery.

Materials and Methods

This study included 34 normal PTGs from 17 consecutive patients who underwent thyroid surgery between December 2020 and March 2021. All normal PTGs were histologically confirmed by intraoperative frozen-section biopsy for autotransplantation. Surgically resected parathyroid specimens were scanned in sterile normal saline using high-resolution US prior to autotransplantation. The US features of echogenicity (hyperechogenicity or hypoechogenicity), echotexture (homogeneous or heterogeneous), size, and shape (ovoid or round) were retrospectively evaluated. The echogenicity of the three PTGs was compared with that of the thyroid parenchyma of the resected thyroid specimens in two patients.

Results

All PTGs showed hyperechogenicity similar to that of gauze soaked in normal saline. Homogeneous hyperechogenicity was observed in 32/34 (94.1%) patients, and the echogenicity of the three PTGs was hyperechoic compared with that of the thyroid parenchyma. The long diameter of the PTGs ranged from 5.1 mm to 9.8 mm (mean, 7.1 mm) and the shape of the PTGs was ovoid in 33/34 (97.1%) patients.

Conclusion

The echogenicity of normal PTG specimens was consistently hyperechoic, and the small ovoid homogeneously hyperechoic structure was a characteristic US feature of the PTGs.

Incidental Parathyroidectomy Among Pediatric Patients Undergoing Thyroid Surgery

OBJECTIVE

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

STUDY DESIGN

Retrospective case-control study.

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

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

A Narrative Review of Preventive Central Lymph Node Dissection in Patients With Papillary Thyroid Cancer - A Necessity or an Excess

Objective

This review article summarises the latest evidence for preventive central lymph node dissection in patients with papillary thyroid cancer taking into account the possible complications and risk of recurrence.

Background

Papillary thyroid cancer is the most frequent histological variant of malignant neoplasms of the thyroid gland. It accounts for about 80-85% of all cases of thyroid cancer. Despite good postoperative results and an excellent survival rate in comparison with many other malignant diseases, tumor metastases to the cervical lymph nodes are frequent. Most researchers agree that the presence of obvious metastases in the lymph nodes requires careful lymph node dissection. It was suggested to perform preventive routine lymphadenectomy in all patients with malignant thyroid diseases referred to surgery.

Methods

It was performed the literature review using the “papillary thyroid cancer”, “central lymph node dissection”, “hypocalcemia”, “recurrent laryngeal nerve paresis”, “metastasis”, “cancer recurrence” along with the MESH terms. The reference list of the articles was carefully reviewed as a potential source of information. The search was based on Medline, Scopus, Google Scholar, eLibrary engines. Selected publications were analyzed and their synthesis was used to write the review and analyse the role of preventive central lymph node dissection in patients with papillary thyroid cancer.

Conclusions

The necessity of preventive central lymph node dissection in patients with differentiated papillary thyroid carcinoma is still controversial. There is much evidence that it increases the frequency of transient hypocalcemia. Due to the fact that this complication is temporary, its significance in clinical practice is debatable. It can also be assumed that an extant of surgery in the neck area is associated with an increased risk of recurrent laryngeal nerve injury. However, most studies indicate that this injury is associated more with thyroidectomy itself than with lymph node dissection. Recurrent laryngeal nerve dysfunction is also a temporary complication in the vast majority of cases. At the same time, a large amount of data shows that central lymph node dissection reduces the risk of thyroid cancer recurrence in two times.

Histopathological Assessment for Papillary Thyroid Carcinoma

Histologic assessments of papillary thyroid carcinoma are crucial for management of patients with the cancer as well as research on the cancer as papillary thyroid carcinoma has different histologic subtypes and many parameters which are essential in predicting the biological aggressiveness of the cancer. The histologic assessments should be guided by universally adopted protocols including World Health Organization (WHO) classification of endocrine tumors, International Collaboration on Cancer Reporting (ICCR) dataset, American Thyroid Association initial risk stratification for differentiated thyroid carcinomas and TNM stage groupings. The essential steps in histologic assessment involve the identification of characteristic features of papillary thyroid carcinoma, correct histologic subtyping, noting the number of carcinomas, measuring the size of the carcinoma, documenting the different aggressive histological parameters (mitotic activity, presence of tumor encapsulation/circumscription, lymphatic vessel invasion, blood vessel invasion, necrosis, extrathyroidal extension), resection margin status, associated pathology, presence of parathyroid gland, lymph node and distant metastases as well as synthesis of pathological stage based on the various clinical, macroscopic, and histological features.

Hypoparathyroidism: State of the Art on Cell and Tissue Therapies

Hypoparathyroidism is an endocrine disorder characterized by low serum calcium levels, high serum phosphorus levels, and by inappropriate or absent secretion of the parathyroid hormone (PTH). The most common therapeutic strategy to treat this condition is hormone replacement therapy with calcium and vitamin D but, unfortunately, in the long term this treatment may not be sufficient to compensate for the loss of endocrine function. Glandular autotransplantation is considered the most effective technique in place of replacement therapy. Although it leads to excellent results in most cases, autotransplantation is not always possible. Allograft is a good way to treat patients who have not been able to undergo autograft, but this technique has limited success due to side effects related to tissue rejection. This therapy is supported by systemic immunosuppression, which leads to the onset of serious side effects in patients, with a risk of endocrine toxicity. Today, research on endocrine disorders is focused on discovering alternative graft therapies that can allow optimal results with the fewest possible side effects. In this review, we will make an update on the current state of the art about the cell and tissue therapy as treatment for hypoparathyroidism, to identify which type of therapeutic strategy could be valid for a future clinical use.

Development and validation of a population-based model for predicting the regional lymph node metastasis in adolescent differentiated thyroid carcinoma

BACKGROUND

Adolescent differentiated thyroid carcinoma (DTC) is a rare type of thyroid cancer that represents a special entity of all endocrine-related cancer. This study aims to establish the first nomogram for predicting the regional (central and lateral) lymph node metastasis (LNM) in the adolescent population for better surgical management.

METHOD

We retrospectively reviewed the clinicopathology characteristics of adolescent patients with DTC in the Surveillance, Epidemiology, and End Results database between 2010 and 2015.

RESULTS

A total of 1,930 adolescent patients between the ages of 10 and 24 years from the SEER database were enrolled in this study. Six predictive factors including age, race, histology, multifocality, extrathyroidal invasion (EI) and tumor size were identified to be significantly associated with the regional LNM via univariate and multivariate logistic regression analyses. These indicators were used to construct a nomogram for predicting the regional LNM in adolescent patients with DTC. Moreover, a satisfied predictive ability of the model was determined with a C-index of 0.794, supported by an internal validation group with a C-index of 0.776. The Decision Curve Analysis and calibration curve further conducted a great agreement in our model.

CONCLUSION

The first predictive model containing multiple factors has been successfully established with good discrimination for predicting the regional LNM in adolescent patients with DTC. This nomogram could effectively help surgeons to make better individualized surgical decision intraoperatively, especially in terms of whether cervical lymph node dissection (LND) is warranted.

Fluorescence Image-Guided Surgery for Thyroid Cancer: Utility for Preventing Hypoparathyroidism

Background: Hypoparathyroidism is one of the most frequent complications of thyroid surgery, especially when associated with lymph node dissection in cases of thyroid cancer. Fluorescence-guided surgery is an emerging tool that appears to help reduce the rate of this complication. The present review aims to highlight the utility of fluorescence imaging in preserving parathyroid glands during thyroid cancer surgery. Methods: We performed a systematic review of the literature according to PRISMA guidelines to identify published studies on fluorescence-guided thyroid surgery with a particular focus on thyroid cancer. Articles were selected and analyzed per indication and type of surgery, autofluorescence or exogenous dye usage, and outcomes. The Methodological Index for Non-Randomized Studies (MINORS) was used to assess the methodological quality of the included articles. Results: Twenty-five studies met the inclusion criteria, with three studies exclusively assessing patients with thyroid cancer. The remaining studies assessed mixed cohorts with thyroid cancer and other thyroid or parathyroid diseases. The majority of the papers support the potential benefit of fluorescence imaging in preserving parathyroid glands in thyroid surgery. Conclusions: Fluorescence-guided surgery is useful in the prevention of post-thyroidectomy hypoparathyroidism via enhanced early identification, visualization, and preservation of the parathyroid glands. These aspects are notably beneficial in cases of associated lymphadenectomy for thyroid cancer.

MANAGEMENT OF ENDOCRINE DISEASE: Postsurgical hypoparathyroidism: current treatments and future prospects for parathyroid allotransplantation

BACKGROUND

Permanent postsurgical hypoparathyroidism (POSH) is a major complication of anterior neck surgery in general and of thyroid surgery in particular. Depending on diagnostic criteria, up to 10% of patients undergoing bilateral thyroid surgery develop POSH. This leads to a multitude of symptoms that decrease the quality of life and burden the healthcare provision through complex needs for medication and treatment of specific complications, such as seizures and laryngospasm.

METHODS

Narrative review of current medical treatments for POSH and of the experience accumulated with parathyroid allotransplantation.

RESULTS

In most patients, POSH is controlled with regular use of calcium supplements and active vitamin D analogues but a significant proportion of patients continue to experience severe symptoms requiring repeated emergency admissions. Replacement therapy with synthetic PTH compounds (PTH1-34, Natpara® and PTH1-84, teriparatide, Forsteo®) has been assessed in multicentre trials, but the use of this medication is restricted by costs and concerns related to the risk of development of osteosarcoma. Based on recent case reports of successful allotransplantation of parathyroid tissue between siblings, there is renewed interest in this technique. Data on selection of donors, parathyroid cell preparation before allotransplantation, site and timing of transplantation, need for immunosuppression and long-term outcomes are reviewed.

CONCLUSION

A prospective trial to assess the efficacy of parathyroid allotransplantation in patients with severely symptomatic protracted post-surgical hypoparathyroidism is warranted.

Measurement of serum intact parathyroid hormone concentration 1 day after total thyroidectomy to assess risk of permanent hypoparathyroidism

OBJECTIVE

This study was performed to assess the clinical value of measuring the intact parathyroid hormone (iPTH) concentration 1 day after total thyroidectomy to estimate the occurrence of permanent hypoparathyroidism (pHPP).

METHODS

Data of 546 patients who underwent total thyroidectomy from February 2008 to December 2018 were retrospectively analyzed. Calcium and iPTH concentrations were collected preoperatively and at 1 day and 6 months postoperatively. Logistic regression was used to analyze the correlation between clinical indexes and postoperative pHPP.

RESULTS

Of the 546 patients, 22 (4.03%) developed pHPP. Multivariate analysis showed that the iPTH and serum calcium concentrations measured 1 day after surgery were independent predictors of the risk of pHPP. An iPTH concentration of 5.51 pg/mL measured 1 day postoperatively was used as the cut-off value, and the area under the curve was 0.956. The risk of pHPP was identified with a sensitivity of 100%, specificity of 85.1%, positive predictive value of 22%, and negative predictive value of 100%.

CONCLUSIONS

The iPTH concentration measured 1 day after total thyroidectomy is closely related to the occurrence of pHPP postoperatively and is an independent predictive risk factor. The postoperative iPTH concentration can be helpful in identifying patients at risk for developing pHPP.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

TYPE OF STUDY

Prognosis Study.

LEVEL OF EVIDENCE

Level IV.

Do carbon nanoparticles really improve thyroid cancer surgery? A retrospective analysis of real-world data

Background

Parathyroid protection and central neck dissection (CND) are basic points of thyroid cancer surgery and draw persistent concern. We aimed to evaluate the value of carbon nanoparticles (CNs) for parathyroid gland protection and CND in thyroid surgery for thyroid cancer patients.

Methods

A total of 386 consecutive thyroid cancer patients were enrolled in the retrospective study. Three hundred thirty-four patients using CNs intraoperatively were included in the CN group, and 52 patients without using CNs or any other helping agent were included in the control group. Intact parathyroid hormone (iPTH) was examined. Medical records and histopathologic reports were reviewed. Histopathologic examination was performed.

Results

There were no statistical significances in demographic and basic surgical information, preoperative iPTH, and serum calcium between the two groups (P > 0.05). In the CN group, the thyroid tissue and central neck lymph nodes were stained black by CNs, while the parathyroid glands were not. Histopathological examination showed that the carbon nanoparticles might accumulated in the subcapsular sinus of lymph nodes compared with the none-stained samples. The staining with CNs did not impact the histopathological examination. There were no significant differences in postoperative hypocalcemia and hypoPT at day 1, 1 month, and half year after surgery between the two groups, respectively. There was a big decline of iPTH level after surgery, whereas the perioperative decreasing amplitude of PTH was not statistically different between the CNs and control group (57.2 ± 28.6 vs 55.7 ± 27.8, P = 0.710). There were 43 patients occurring incidental parathyroidectomy in the CN group (43/334, 12.9%) and 7 patients in the control group (7/52, 13.5%), without significant difference (P = 0.907). There was no significant difference in the number of lymph nodes identified by pathology per patient between the CNs and control group regardless of unilateral and bilateral CND.

Conclusions

Carbon nanoparticles help highlight parathyroid glands and lymph nodes in thyroidectomy, but generate no significant benefit for parathyroid glands protection and lymph node dissection. The value of carbon nanoparticles in thyroid cancer surgery should not be exaggerated and needs further evaluation.

Rare concurrence of ectopic intrathyroidal parathyroid gland and papillary thyroid carcinoma within a thyroid lobe: A care-compliant case report

RATIONALE

The inferior parathyroid glands derive from the third branchial pouch and seldom ectopically migrate to thyroid grand, mediastinum, thymus. Ectopic intrathyroidal parathyroid grand (ETPG) is rare and it cannot be consistently detected by any imaging examinations. The unusual ETPG is easily resected during thyroidectomy, which might cause postoperative hypoparathyroidism. Auto-transplantation of even a parathyroid gland can restore parathyroid function to some extent. Until now, there are not any guidelines on the management of ETPG.

PATIENT CONCERNS

Without any symptoms, a 27-year-old female patient was admitted to our hospital for a thyroid nodule. Thyroid ultrasonography demonstrated a hypoechoic nodule, measuring 0.6 cm × 0.6 cm × 0.7 cm, with multiple punctate micro-calcifications within the right thyroid lobe. Thyroid function tests were normal. The invasive fine needle aspiration cytology for the thyroid nodule was rejected by patient.

DIAGNOSES

The patient was firstly diagnosed as right thyroid hypoechoic nodule, which was pathologically proved to be papillary thyroid carcinoma (PTC) finally.

INTERVENTIONS

The patient underwent right thyroidectomy, central compartment neck dissection, parathyroid exploration, and auto-transplantation of the normal ETPG.

OUTCOMES

The right thyroid hypoechoic nodule was diagnosed as PTC by pathological examination. The inferior parathyroid gland could not found in normal locations. On the cut surface of excised thyroid lobe, a yellow and soft nodule was discovered and it was pathologically diagnosed as a normal parathyroid grand. In the end, auto-transplantation of the normal ETPG was conducted. Postoperative follow-ups found both serum calcium and parathyroid hormone tests were normal.

LESSONS

ETPG in a patient with PTC is easily overlooked and unexpectedly excised for its rarity. ETPG brings about a failed parathyroid exploration. However, within the thyroid parenchyma, it might be occasionally discovered by cutting a thyroid lobe into slices. Auto-transplantation of normal ETPG is necessary.

Hypocalcemia after Total Thyroidectomy in Graves Disease

CONTEXT

Total thyroidectomy has been shown to provide a cost-effective and efficient method of permanently treating Graves disease; however, hypocalcemia can be a common complication.

OBJECTIVE

To evaluate the risk of hypocalcemia after total thyroidectomy in patients with vs without Graves disease.

DESIGN

The 2016 American College of Surgeons National Surgical Quality Improvement Program participant use data files for procedure-targeted thyroidectomy and from 5871 patients were merged. This study included any patient who underwent total thyroidectomy.

MAIN OUTCOME MEASURES

Whether symptomatic hypocalcemia developed anytime within 30 days after the thyroidectomy. A clinically severe hypocalcemic event was also evaluated as a secondary outcome measure.

RESULTS

Of the 2143 patients who underwent total thyroidectomy, 222 patients experienced hypocalcemia after surgery, 124 of whom had symptomatic hypocalcemia postoperatively. Among patients with hypocalcemia, 16.3% had Graves disease, whereas only 9.4% of patients without Graves disease experienced significant hypocalcemia. Multivariable logistic regression analysis revealed that women (odds ratio = 1.79; 95% confidence interval = 1.16-2.76; p = 0.009) and patients who underwent parathyroid autotransplantation (odds ratio = 1.91; 95% confidence interval = 1.30-2.81; p = 0.001) were at greater risk of development of hypocalcemia. Older patients were less likely to experience hypocalcemia postoperatively (odds ratio = 0.586; 95% confidence interval = 0.44-0.79; p = 0.0001).

CONCLUSION

Patients with Graves disease are about twice as likely to experience hypocalcemia or clinically severe hypocalcemia postoperatively than are patients without the disease.

Superior parathyroid blood supply safety in thyroid cancer surgery: A randomized controlled trial

BACKGROUND

To evaluate the clinical value of a technique protecting blood supply to the superior parathyroid during surgery for thyroid cancer.

MATERIALS AND METHODS

The observation group comprised 113 patients admitted to our hospital during the period from January 1, 2016 to December 31, 2016, who were diagnosed with thyroid cancer and treated by surgery using a technique protecting blood supply to the superior parathyroid. The control group comprised 113 patients diagnosed with thyroid cancer who were treated by surgery using the conventional technique. Postoperative parathyroid function damage and blood calcium levels were assessed in both groups.

RESULTS

The incidences of hypocalcemia and low parathyroid hormone in the observation and control groups were 10.6% and 31.9%, and 14.2% and 35.4%, respectively. The relative risk (RR) of the control group was increased (RR = 3.009 for control; RR = 2.493 for observation). Univariate logistic regression analysis showed that postoperative temporary hypoparathyroidism was associated with lymph node metastasis, use of the above protective technique, and tumor size [(odds ratio, OR = 1.936, 95%CI 1.029-3.643; P = 0.041), (OR = 0.301, 95%CI 0.156-0.579; P = 0.001) and (OR = 2.022, 95%CI 1.089-3.756; P = 0.026), respectively]. Postoperative temporary hypoparathyroidism was also associated with lymph node dissection (Bilateral vs. No, P = 0.003) and T classification (T3 vs. T1, P = 0.034). Multivariate logistic regression analysis showed that, after including significant independent variables of univariate logistic regression analysis (e.g., lymph node metastasis, lymph node resection, protective technique, tumor size, and T classification), the protective technique was a factor supporting reduced incidence of postoperative temporary hypoparathyroidism (OR = 0.325, 95% CI 0.163-0.648; P = 0.001).

CONCLUSION

Application of a technique protecting blood supply to the superior parathyroid during thyroid cancer surgery effectively reduced the incidence of postoperative temporary hypoparathyroidism. However, because of the imbalance in lymph node dissection between the two groups, confounding factors could not be completely eliminated, and matched pair analysis is needed to eliminate these factors.

Hypocalcemic disorders

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