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

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.

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.

Incidence of Post-Thyroidectomy Hypoparathyroidism and Associated Preoperative and Intraoperative Risk Factors

INTRODUCTION

Thyroidectomy technique and extent are related to parathyroid injury and hypoparathyroidism. Total thyroidectomy is one of the most commonly performed endocrine surgeries, and the majority of patients recover completely without any complications. However, persistent hypoparathyroidism is the most prevalent long-term consequence following total thyroidectomy. While it is seldom deadly, it can cause severe morbidity for the patient and raise healthcare expenses.

METHODS

This retrospective cohort study was conducted at King Abdulaziz Medical City, Jeddah, Saudi Arabia. We included all confirmed thyroid cancer cases that underwent thyroidectomy with or without neck dissection between July 2016 and August 2022. The data was collected from a chart review of the electronic medical record system (BEST-care), and a data collection sheet was utilized. SPSS version 26 was used to analyze the data.

RESULTS

A total of 192 patients undergoing thyroid surgery were enrolled. One hundred forty-three (74.5%) were females and the mean age of participants was 45.29 ± 16.88 years. Most patients, 170 (88.5%), had a papillary histological type, and total thyroidectomy was performed in 150 (78.1%). A significant association was found between the type of surgery and postoperative hypoparathyroidism (p=<0.05*). In addition, hypocalcemia was seen in 147 (76.6%) of the patients. Postoperative hypoparathyroidism was significantly higher among patients who had asymptomatic postoperative hypocalcemia and those who received IV calcium gluconate (p=<0.05*). Moreover, postoperative hypocalcemia, hypomagnesemia, and hyperphosphatemia were significantly associated with postoperative hypoparathyroidism (p=<0.05*).

CONCLUSION

The incidence of postoperative hypoparathyroidism is significantly higher among patients who underwent total thyroidectomy and had a normal level of preoperative parathyroid hormone (PTH) and magnesium (Mg) levels. Identifying these factors is a crucial step to minimize the occurrence of such complications.

Extent of thyroidectomy and paratracheal lymph node dissection in total pharyngolaryngectomy for pyriform sinus cancer, and recurrence, survival, and postoperative hypoparathyroidism: A multicenter retrospective study

BACKGROUND

Total pharyngolaryngectomy (TPL) is standard treatment for hypopharyngeal cancer. However, extensive thyroidectomy and paratracheal nodal dissection (PTND) can cause hypoparathyroidism. We sought to determine the optimum extent of resection.

METHODS

We analyzed the clinicopathological information of 161 pyriform sinus cancer patients undergoing TPL from 25 Japanese institutions. Rates of recurrence and risk factors for hypoparathyroidism, as well as incidence of pathological contralateral level VI nodal metastasis and stomal recurrence, were investigated.

RESULTS

The extent of thyroidectomy and nodal dissection were not independent risk factors for recurrence. Incidences of contralateral level VI nodal involvement and stomal recurrence were 1.8% and 1.2%, respectively. Patients undergoing hemithyroidectomy/ipsilateral PTND did not develop stomal recurrence and had the lowest incidence of hypoparathyroidism. Prognosis in patients without tracheostomy prior to hemithyroidectomy/ipsilateral PTND was comparable to that with more extensive resections.

CONCLUSIONS

Hemithyroidectomy/ipsilateral PTND may be sufficient for pyriform sinus cancer cases without tracheostomy.

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

OBJECTIVE

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

DATA SOURCES

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

REVIEW METHODS

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

RESULTS

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

CONCLUSIONS

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

Validating the risk of hypoparathyroidism after total thyroidectomy in a population-based cohort: plea for improved follow-up

BACKGROUND

A previous nationwide study from Sweden showed that the rate of permanent hypoparathyroidism is high and under-rated in the Swedish Quality Register. This retrospective population-based study aimed to validate the rate and diagnosis of permanent hypoparathyroidism found in the previous study. A secondary aim was to assess the relationship between the rate of low parathyroid hormone (PTH) levels within 24 h after surgery and the rate of permanent hypoparathyroidism.

METHODS

All patients who underwent total thyroidectomy from 2005 to 2015 in a region of Sweden were included. Data were retrieved from local health records, the National Patient Registry, the Swedish Prescribed Drug Registry, and the Swedish Quality Register. A strict definition of permanent hypoparathyroidism was used, including biochemical data and attempts to stop the treatment.

RESULTS

A total of 1636 patients were included. Altogether, 143 patients (8.7 per cent) developed permanent hypoparathyroidism. Of these, 102 (6.2 per cent) had definitive permanent hypoparathyroidism, whereas 41 (2.5 per cent) had possible permanent hypoparathyroidism, because attempts to stop the treatment were lacking (28) or patients were lost to follow-up (13). The agreement between the Swedish Quality Register and the chart review was 29.3 per cent. A proportion of 23.2 per cent with a PTH level below the reference value corresponded to a 6.7 per cent rate of permanent hypoparathyroidism.

CONCLUSION

The risk of permanent hypoparathyroidism after total thyroidectomy is high. Some patients are overtreated because attempts to stop the treatment are lacking. Quality registers might underestimate the risk of permanent hypoparathyroidism. Approximately one-quarter of all patients with low PTH levels immediately after surgery developed permanent hypoparathyroidism.

Wire-guided localization and surgical resection of non-palpable recurrent of thyroid carcinoma: A STROBE-compliant, retrospective cohort study

BACKGROUND

Information on hook-wire guided (HWG) surgery for non-palpable thyroid carcinoma (TC), locoregional-recurrent disease (LRRD) is scarce. We analyze the results of HWG resection compared with the traditional procedure.

METHODS

Cohort study performed between January 2016 and December 2020. Patients with TC and non-palpable LRRD were included. A "Standard cohort", patients with non-HWG resection and "HWG cohort", with HWG resection of LRRD were defined. Surgical morbidity, re-recurrent/progressive disease (RRD), and re-recurrence-free survival (RRFS) were defined.

RESULTS

43 and 23 patients were assigned to the Standard or HWG cohorts, respectively. Complications occurred in 28 % and 17.3 % of cases, in control or HWG cohorts, respectively. HWG cohort, size of primary TC, 131I dose >150 mCi, and thyroglobulin level >1 ng/ml at detection of LRRD were associated with RRD. HWG cohort, thyroglobulin level at LRRD, 131I treatment, and dose were associated with RRFS.

CONCLUSIONS

HWG surgery of non-palpable TC LRRD had improved results regarding surgical morbidity, RRD, and RRFS.

The Obesity Paradox in Thyroid Surgery: Is Higher BMI Protective Against Hypoparathyroidism?

BACKGROUND

With a demonstrated association between adiposity and parathyroid hormone (PTH) levels, we hypothesized that patients with a higher body mass index (BMI) would have lower rates of postoperative hypoparathyroidism following total thyroidectomy.

METHODS

retrospective review of patients undergoing total thyroidectomy from 2015 to 2021. Demographics, BMI, surgical indications, and laboratory data including pre- and postoperative PTH values were examined.

RESULTS

Of the 352 patients with complete clinicopathologic data, most were female (n = 272, 77.3%) with an average age of 42.7 (SD+/-19.4). Obese (BMI 30-39.99) was most common BMI group (n = 108, 30.8%), with 11.7% (n = 41) morbidly obese (BMI > 40). Morbidly obese patients had significantly higher postoperative PTH levels than BMI < 18.5 (46.0 vs 19.3 pg/mL, P = .004). Patient race was significantly associated with pre- and postoperative PTH (P = .03, P = .004.) On multivariable analysis, preoperative PTH, race, and BMI were independent predictors of higher postoperative PTH (P < .05 for all).

DISCUSSION

Patients with higher BMI and non-white race have relative protection from postoperative hypoparathyroidism.

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

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

An improved method of searching inferior parathyroid gland for the patients with papillary thyroid carcinoma based on a retrospective study

Objective

Many surgeons knew the importance of parathyroid gland (PG) in the thyroid surgery, but it was even more difficult to be protected. This study aimed at evaluating the effectiveness of the improved method of searching inferior parathyroid gland (IPG).

Methods

213 patients were enrolled and divided into test and control groups according to different methods of searching IPG in the surgery. Consequently, we compared the surgical outcome parameters between the two groups, including the operative time, numbers of PG identifying (PG protection in situ, PG auto-transplantation, and PG accidental removal), numbers of the total lymph node (LN) and metastatic LN, parathyroid hormone (PTH), transient hypoparathyroidism, transient recurrent laryngeal nerve palsy, and postoperative bleeding.

Results

We identified 194 (194/196, 98.98%) and 215 (215/230, 93.48%) PGs in the test group and control group, respectively, and there was a significant difference (P = 0.005), and this result was due to IPG identification differences (96/98, 97.96% vs. 100/115, 86.96%, P = 0.004). Meanwhile, there was a lower ratio of IPG auto-transplantation in the test group compared with that in the control group (46.94% vs. 64.35%, P = 0.013). Serum PTH one day after the operation was 3.65 ± 1.86 vs. 2.96 ± 1.64 (P = 0.043) but with no difference at 6 months. There were no differences in metastatic LN and recurrent laryngeal nerve palsy between two groups.

Conclusion

The improved method of searching IPG was simple, efficient, and safe, which was easy to be implemented for searching IPG and protecting it well.

Etiology and Pathophysiology of Hypoparathyroidism: A Narrative Review

The approach utilized a systematic review of the medical literature executed with specifically designed criteria that focused on the etiologies and pathogenesis of hypoparathyroidism. Enhanced attention by endocrine surgeons to new knowledge about parathyroid gland viability are reviewed along with the role of intraoperative parathyroid hormone (ioPTH) monitoring during and after neck surgery. Nonsurgical etiologies account for a significant proportion of cases of hypoparathyroidism (~25%), and among them, genetic etiologies are key. Given the pervasive nature of PTH deficiency across multiple organ systems, a detailed review of the skeletal, renal, neuromuscular, and ocular complications is provided. The burden of illness on affected patients and their caregivers contributes to reduced quality of life and social costs for this chronic endocrinopathy. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

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

This clinical practice guideline addresses the prevention, diagnosis, and management of hypoparathyroidism (HypoPT) and provides evidence-based recommendations. The HypoPT task forces included four teams with a total of 50 international experts including representatives from the sponsoring societies. A methodologist (GG) and his team supported the taskforces and conducted the systematic reviews. A formal process following the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology and the systematic reviews provided the structure for seven of the guideline recommendations. The task force used a less structured approach based on narrative reviews for 20 non-GRADEd recommendations. Clinicians may consider postsurgical HypoPT permanent if it persists for >12 months after surgery. To predict which patients will not develop permanent postsurgical HypoPT, we recommend evaluating serum PTH within 12 to 24 hours post total thyroidectomy (strong recommendation, moderate quality evidence). PTH > 10 pg/mL (1.05 pmol/L) virtually excludes long-term HypoPT. In individuals with nonsurgical HypoPT, genetic testing may be helpful in the presence of a positive family history of nonsurgical HypoPT, in the presence of syndromic features, or in individuals younger than 40 years. HypoPT can be associated with complications, including nephrocalcinosis, nephrolithiasis, renal insufficiency, cataracts, seizures, cardiac arrhythmias, ischemic heart disease, depression, and an increased risk of infection. Minimizing complications of HypoPT requires careful evaluation and close monitoring of laboratory indices. In patients with chronic HypoPT, the panel suggests conventional therapy with calcium and active vitamin D metabolites as first-line therapy (weak recommendation, low-quality evidence). When conventional therapy is deemed unsatisfactory, the panel considers the use of PTH. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Impact of energy-based devices in pediatric thyroid surgery

BACKGROUND

Energy-based devices are surgical devices increasingly utilized for thyroid surgery, owing to a reduction of operative time and surgical related complications. The aim of the study is to evaluate whether the use of energy-based devices could improve the complication rate in pediatric thyroid surgery.

METHODS

This is a retrospective observational study. We identified 177 consecutive pediatric patients (Group A) with thyroid diseases, surgically treated by energy-based devices and 237 patients (Group B) treated by conventional clamp and tie technique and matched for sex, age and indication for surgery. Transient and permanent complications rate, operative time and length of hospital stay were compared between the two groups.

RESULTS

Patients of Group A experienced a lower complication rate compared to Group B. Particularly, transient (11.3 vs. 19% p < 0.05) and permanent post operative hypoparathyroidism (1.7 vs. 5.5%, p < 0.05) were lower in Group A. Moreover, operative time was also shorter in Group A compared to Group B and this difference was statistically significant in patients who performed total thyroidectomy alone and total thyroidectomy associated with central compartment neck dissection (p < 0.05). Length of hospital stay was lower in Group A than in Group B, but this difference was statistically significant only for microfollicular lesion (p < 0.05).

CONCLUSION

The use of energy-based devices has a key role in reducing surgical related complications, particularly transient and permanent hypoparathyroidism, operative time and length of hospital stay in pediatric patients treated with thyroid surgery.

LEVEL OF EVIDENCE

Level III.

TYPE OF STUDY

Retrospective comparative study.

Factors associated with postoperative hypocalcemia following thyroidectomy in childhood

BACKGROUND

Postoperative hypocalcemia is a frequent complication after thyroidectomy. Hypoparathyroidism may develop as transient (TtHP), with normalization within six months from surgery, or permanent (PtHP) if the patient requires replacement therapy. We analyzed factors associated with the development of postoperative hypoparathyroidism and in detail PtHP following thyroid surgery in a pediatric population.

PROCEDURE

A retrospective multicenter study analyzing 326 patients was carried out. We recorded gender, age, tumor size, thyroiditis, extrathyroidal extension, lymph node dissection (central/lateral compartment, unilateral/bilateral), parathyroid autotransplantation, and histology. Additionally, calcium levels were acquired postoperatively.

RESULTS

We analyzed pediatric patients ≤18 years who underwent thyroidectomy clustered into age groups (≤15 or > 15). Patients' mean follow-up was 5.8 years (1-11 years). Postoperative hypoparathyroidism occurred in 36 (11.0%): 20 cases (6.13%) developed PtHP. Postoperative hypoparathyroidism was more frequent in younger patients (P = 0.014), in larger tumors (P < 0.001), in case of extrathyroidal extension (P = 0.037), and in central compartment (P = 0.020) and bilateral lymph node dissection (P = 0.030). PtHP was more frequent in older patients (P = 0.014), in case of thyroiditis (P < 0.001), and extrathyroidal extension (P < 0.001). Concerning the first postoperative calcium level measurement, in the postoperative hypoparathyroidism group, we registered a 8.17 mg/dL value with 14% pre/postoperative decrease (Δ_Ca ), whereas in PtHP patient group calcium level was 7.91 mg/dL with 16.7% Δ_Ca .

CONCLUSIONS

The risk of postoperative hypoparathyroidism is related to younger age, tumor size, central compartment and bilateral lymph node dissection, extrathyroidal extension, and decrease in postoperative calcium levels. The risk of PtHP is related to older age, thyroiditis, extrathyroidal extension, and decrease in postoperative calcium levels.

Near-Infrared Autofluorescence Imaging in Thyroid Surgery: A Systematic Review and Meta-Analysis

OBJECTIVE

This meta-analysis aimed to assess the position of near-infrared autofluorescence (NIRAF) imaging in the recognition and protection of the parathyroid gland (PG) during thyroidectomy.

METHODS

The PubMed, MEDLINE, EMBASE, Web of Science, and Cochrane Library databases were searched up to June 2021. The primary outcome was to evaluate the rates of postoperative hypocalcemia, inadvertent PG resection, and autotransplantation of PG when adopting NIRAF imaging compared with standard naked-eye (N-E) surgery.

RESULTS

Eight studies with 2,889 patients were enrolled in the analysis. Our analysis showed that the incidence of transient hypocalcemia was 7.11% (60/844) in the NIRAF group and 22.40% (458/2045) in the N-E group (p < 0.0001) and the rate of transient hypoparathyroidism was 28.31% (126/445) and 33.36% (496/1487) in the NIRAF and N-E groups (p = 0.0008). The rate of inadvertent resection of PGs was 7.65% (55/719) in the NIRAF group and 14.39% (132/917) in the N-E group (p < 0.0001). No significant difference was observed in other indexes including the pooled proportion of permanent hypocalcemia and rate of PG autotransplantation.

CONCLUSIONS

The application of NIRAF imaging in thyroidectomy can help lower the incidence of inadvertent PG resection and reduce the risk of postoperative hypocalcemia and hypoparathyroidism compared with N-E recognition.

Achieving the learning curve in total thyroidectomy: a prospective evaluation on resident's training by CUSUM and KPSS analysis

INTRODUCTION

Total thyroidectomy (TT) is one of the most common procedures among general and endocrine surgeons worldwide. The conventional approach by neck incision is still the most frequently used, despite the growth of mini-invasive approaches. Controversies exist about the optimal learning curve for resident surgeons approaching this procedure. The aim of this study was to compare TT performed by experienced surgeons and residents in two academic hospitals, to define the correct shape of the specific learning curve.

METHODS

Between January 2016 and December 2018 patients undergoing TT in two academic departments were prospectively enrolled. In each department patients were divided into four groups: a reference group (A), consisting of 50 consecutive patients operated on by a senior surgeon, and three other groups (B, C, D) of 50 patients each where thyroidectomy was carried out by three different general surgery residents in their last 3 years of residency, respectively. Data were analysed by CUSUM and KPSS tests in order to compare operative time (OT) and its stabilisation during the learning curve.

RESULTS

Data from CUSUM test reported that residents could perform TT with OT similar to the senior surgeon after approximately 25-30 procedures, while the KPSS test showed that residents became more stable after 30 procedures, with no increase in perioperative complications.

CONCLUSIONS

This prospective study shows how a specific training in thyroid surgery can be reliable thanks to experienced tutors, and confirmed that the effect of dedicated and programmed training may result in positive outcomes for patients requiring thyroidectomy.

Preoperative prophylactic active vitamin D to streamline total thyroidectomy

Background

Hypocalcaemia is a common complication after total thyroidectomy (TT). Treatment consists of calcium and active vitamin D supplementation. Low levels of vitamin D before surgery have been shown to be a risk factor for postoperative hypocalcaemia, yet studies examining routine preoperative vitamin D supplementation have shown conflicting results. This retrospective cohort study aims to investigate the potential benefit of preoperative active vitamin D supplementation on hypocalcaemia and its symptoms after TT.

Methods

This study included patients undergoing TT at Uppsala University Hospital from January 2013 to December 2020, resulting in a total of 401 patients after exclusion. Routine preoperative alfacalcidol treatment was initiated for all TT patients in January 2017 resulting in two groups for comparison: one group (pre-January 2017) that was prescribed preoperative alfacalcidol and one that was not. Propensity score matching was used to reduce bias. The primary outcome was early postoperative hypocalcaemia (serum calcium, S-Ca less than 2.10 mmol/l); secondary outcomes were symptoms of hypocalcaemia and length of stay.

Results

After propensity score matching, there were 108 patients in each group. There were 2 cases with postoperative day one S-Ca less than 2.10 in the treated group and 10 cases in the non-treated group (P < 0.001). No patients in the treated group had a S-Ca below 2.00 mmol/l. Preoperative alfacalcidol was associated with higher mean serum calcium level day one (2.33 versus 2.27, P = 0.022), and reduced duration of hospital stay (P < 0.001). There was also a trend toward fewer symptoms of hypocalcaemia (18.9 per cent versus 30.5 per cent, P = 0.099).

Conclusions

Prophylactic preoperative alfacalcidol was associated with reduced biochemical hypocalcaemia and duration of hospital stay following TT. Also, with this protocol, it is suggested that routine day 1 postoperative S-Ca measurement is not required.

Trastornos posoperatorios del metabolismo del calcio postiroidectomía

Introducción: revisión narrativa que revela como la tiroidectomía ha aumentado en los últimos años y con ella sus complicaciones: la hipocalcemia y el hipoparatiroidismo. Métodos: los motores de búsqueda utilizados fueron PubMed, Clinical Key, Embase, Cochrane y Lilacs, se incluyeron referencias en español e inglés, publicadas entre 2016 y 2020. Los artículos seleccionados se revisaron utilizando CONSORT, STROBE o PRISMA, según el caso. Resultados: fueron seleccionados 35 artículos que tenían relación directa con el tema, entre ellos: metanálisis, revisiones sistemáticas, estudios prospectivos y observacionales, revisiones narrativas y consensos de expertos, procedentes de los cinco continentes. La hipocalcemia y el hipotiroidismo en sus dos formas se relacionan con la afectación de la vascularización de las glándulas paratiroides o su exérecis accidental, existiendo factores predisponentes propios del paciente, derivados de la técnica quirúrgica o la característica patológica de la lesión en el tiroides. Como estrategias de prevención disponemos de herramientas ópticas para definir en el perioperatorio la disposición de las paratiroides; además existe la posibilidad de autotrasplantarlas al identificarlas en la pieza anatómica. El mejor marcador del estado metabólico del calcio es la PTHi. Conclusiones: la preservación de las paratiroides y de su irrigación es la mejor estrategia para prevenir los trastornos posoperatorios del calcio.

[Prevention and treatment of postoperative hypoparathyroidism]

Hypoparathyroidism is a failure of parathyroid glands characterized by reduced serum concentration of parathyroid hormone, hypocalcemia and hyperphosphatemia. The most common cause of hypoparathyroidism is resection or damage to parathyroid glands during thyroid surgery. Postoperative hypoparathyroidism is still an urgent problem, as it requires additional treatment and prolongs hospital-stay. Considering available literature data, the authors analyze various methods of intraoperative prevention of hypoparathyroidism.

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.

Role of the 2018 American Thyroid Association statement on postoperative hypoparathyroidism: a 5-year retrospective study

Background

Definitions of postoperative hypoparathyroidism (hypoPT) have never reached consent until the American Thyroid Association (ATA) statement was released, with new characteristics and challenges.

Methods

Patients with papillary thyroid carcinoma who underwent primary total thyroidectomy between January 2013 and June 2018 were retrospectively enrolled. Symptoms of hypocalcemia and their frequency were stringently followed. Patients were divided into groups according to the ATA statement. Incidence of postoperative hypoPT and serum parathyroid hormone levels accompanied by calcium levels, from 1-day to at least 24-month follow-up.

Results

A total of 1749 patients were included: 458 (26.2%) had transient and 63 (3.6%) had permanent hypoPT. Transient hypoPT was found in 363 (20.7%) patients with biochemical hypoPT, 72 (4.1%) with clinical hypoPT, and 23 (1.3%) with relative hypoPT; permanent hypoPT was detected in 8 (0.5%) patients with biochemical hypoPT, 55 (3.1%) with clinical hypoPT, and none with relative hypoPT. Female sex, age ≥ 55 years, unintentional parathyroid gland resection, and autotransplantation of ≥ 2 parathyroid glands were independent risk factors for transient biochemical hypoPT. Age ≥ 55 years, bilateral central neck dissection, and isthmus tumor location were independent risk factors for transient clinical hypoPT. A postoperative 1-day percentage of parathyroid hormone (PTH) reduction of > 51.1% was an independent risk factor for relative hypoPT (odds ratio, 4.892; 95% confidence interval, 1.653–14.480; P = 0.004). No independent risk factor for permanent hypoPT was found.

Conclusion

ATA diagnostic criteria for postoperative hypoPT are of great value in differentiating patients by hypocalcemia symptoms and choosing corresponding clinical assistance; however, they may underestimate the actual incidence.

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Supplementary Information

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

The long-term need for calcium supplementation after incidental parathyroidectomy

Objectives

Methods

Results

Conclusion

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Protective strategy of parathyroid glands during thyroid lobectomy: A retrospective cohort and case-control study

Parathyroid protection during thyroid lobectomy was not illustrated previously. Aim of this study was to find out the influence of parathyroid glands in situ preservation and autotransplantation on postoperative parathyroid function in thyroid lobectomy.Consecutive patients who underwent primary thyroid lobectomy with unilateral central neck dissection for papillary thyroid carcinoma in our center were included retrospectively. Postoperative hypoparathyroidism was defined as low parathyroid hormone (PTH) levels (<1.6 pmol/L) and keeping over 6 months was defined as permanent. Patients were divided into 3 groups: all identified parathyroid glands preserved in situ (preservation group); at least one parathyroid gland autotransplanted without accidental resection (autotransplantation group); at least one parathyroid gland accidental resected (resection group).A total of 425 patients were included. No permanent hypoparathyroidism was reported, and the rates of transient hypoparathyroidism were similar among all groups. Significantly lower serum PTH levels were found in autotransplantation group versus preservation group at postoperative 1-day (3.77 ± 1.61 vs 4.72 ± 2.31, P < .001). Transient hypoparathyroidism was significantly associated with reduced intraoperative carbon nanoparticles utilization (57.1% vs 77.4%, P = .039).Thyroid lobectomy was a safe surgical method for parathyroid protection no matter the practice to ipsilateral parathyroid glands. However, preservation of all parathyroid glands was still recommended considering relatively stable PTH levels.

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.

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.

The Optimal Parathyroid Hormone Cut-Off Threshold for Early and Safe Management of Hypocalcemia After Total Thyroidectomy

OBJECTIVE

To define optimal intact parathyroid hormone (iPTH) cut-off threshold predictive of hypocalcemia after total thyroidectomy for safe and effective postoperative management.

METHODS

This prospective single center study was done in 2 phases. In phase I, predictors of symptomatic hypocalcemia were analyzed and the receiver operating characteristic curve was used to define the optimal iPTH cut-off threshold predictive of hypocalcemia. Phase II studied giving prompt prophylactic supplemental calcium and vitamin D to all patients who had iPTH levels below the calculated threshold, while phase I patients were given prompt selective supplementation if they had postoperative hypocalcemia or symptoms.

RESULTS

Univariate analysis of patients in phase I showed that postoperative iPTH was the only significant variable that can predict symptomatic hypocalcemia. Using receiver operating characteristic curve and Youden index, the confirmed optimal cut-off threshold predictive of hypocalcemia was iPTH 19.95 pg/mL, with area under the curve of 0.903, 100% sensitivity, negative predictive value, and highest Youden index, while iPTH 15 pg/mL and iPTH 10 pg/mL were less optimal. Symptomatic hypocalcemia occurred in 30% of the phase I cohort who received selective supplementation versus 3% of those in the phase II cohort who received prophylactic supplementation. Return to emergency department and need for intravenous calcium were also significantly better in phase II.

CONCLUSION

iPTH cut-off for post-thyroidectomy hypocalcemia was 19.95 pg/mL. Low-risk patients were discharged with no supplementation while all high-risk patients received prompt calcium and vitamin D supplementation, which led to effective hypocalcemia management and safe 24-hour discharge.

Does Preoperative Calcium and Calcitriol Decrease Rates of Post-Thyroidectomy Hypocalcemia? A Randomized Clinical Trial

BACKGROUND

Postoperative hypocalcemia is the most common complication after thyroidectomy. Postoperative supplementation with calcium and calcitriol reduces its occurrence; however, prophylactic preoperative supplementation has not been studied systematically. The primary objective of this study was to determine whether pre- and postoperative calcium and calcitriol supplementation reduces postoperative hypocalcemia after total thyroidectomy compared with postoperative supplementation alone.

STUDY DESIGN

We conducted a single-institution prospective randomized trial enrolling 82 patients undergoing total thyroidectomy from July 2017 through May 2019. Those undergoing partial thyroidectomy or concurrent planned parathyroidectomy were excluded. The intervention group started calcitriol 0.25 μg po bid and calcium carbonate 1,500 mg po tid 5 days preoperatively and continued postoperatively. The control group started these medications postoperatively. The primary end point was clinical or biochemical hypocalcemia. Secondary outcomes were postoperative calcium levels, need for intervention, length of stay, and readmission.

RESULTS

Thirty-eight patients were randomized to the intervention group and 44 to the control group. There were 12 episodes of hypocalcemia; 5 (13.2%) in the intervention and 7 (15.9%) in the control group (p = 0.76). No differences were found in secondary outcomes; including postoperative calcium levels at each measured time point, need for intervention (n = 10 [26.3%], n = 15 [34.1%]; p = 0.48), length of stay (mean [SD] 32.3 [15.6] hours, 30.7 [10.5] hours; p = 0.6), or readmissions (n = 0 [0.0%], n = 3 [6.8%]; p = 0.24).

CONCLUSIONS

Starting supplementation with calcium and calcitriol preoperatively does not reduce postoperative hypocalcemia compared with postoperative supplementation alone after total thyroidectomy. These findings do not support the practice of routine calcium and calcitriol supplementation before total thyroidectomy.

Etiology and Diagnosis of Permanent Hypoparathyroidism after Total Thyroidectomy

Postoperative parathyroid failure is the commonest adverse effect of total thyroidectomy, which is a widely used surgical procedure to treat both benign and malignant thyroid disorders. The present review focuses on the scientific gap and lack of data regarding the time period elapsed between the immediate postoperative period, when hypocalcemia is usually detected by the surgeon, and permanent hypoparathyroidism often seen by an endocrinologist months or years later. Parathyroid failure after thyroidectomy results from a combination of trauma, devascularization, inadvertent resection, and/or autotransplantation, all resulting in an early drop of iPTH (intact parathyroid hormone) requiring replacement therapy with calcium and calcitriol. There is very little or no role for other factors such as vitamin D deficiency, calcitonin, or magnesium. Recovery of the parathyroid function is a dynamic process evolving over months and cannot be predicted on the basis of early serum calcium and iPTH measurements; it depends on the number of parathyroid glands remaining in situ (PGRIS)—not autotransplanted nor inadvertently excised—and on early administration of full-dose replacement therapy to avoid hypocalcemia during the first days/weeks after thyroidectomy.

Central neck dissection is an independent risk factor for incidental parathyroidectomy

OBJECTIVE

This study aims to determine the frequency of incidental parathyroidectomy (IP), to reveal the risk factors and to present the clinical importance of IP through the experiences of our clinic.

MATERIALS AND METHODS

Patients undergoing thyroid surgery between June 2016 and May 2019 were reviewed retrospectively. Along with demographic data, surgery reports, pathology results and postoperative follow-up data were examined. Factors assumed to be associated with IP and postoperative hypocalcemia were compared between the IP group and the non-IP group.

RESULTS

A total of 633 patients with a mean age of 48 ± 13 years were included in this study. IP was detected in 138 (21.8%) patients and parathyroid glands were localized 29.72% intrathyroidal. Postoperative hypocalcemia in the IP group was approximately 2-fold higher than the no-IP group (%15.94 to %7.27), (p < .001). Gender (p = .014), body mass index (p = .021), both preoperative and postoperative diagnosis of malignancy (p < .001) and performing central neck dissection (CND) (p < .001) were significantly associated with IP in univariate analysis. However, multivariate analysis demonstrated that CND was independently associated with IP (OR = 0.301, 95% Cl: 0.161-0.562, p < .001).

CONCLUSION

This study reveals that IP increases the frequency of postoperative temporary and permanent hypocalcemia in patients undergoing thyroid surgery, and CND is the only independent risk factor for IP. Highlights of the study This study reveals that central neck dissection is the most important and only independent risk factor for incidental parathyroidectomy in patients undergoing thyroid surgery. According to our analysis, both temporary and permanent hypocalcemia, which occurs in the postoperative period, are associated with incidental parathyroidectomy.

Complications After Thyroidectomy in Children: Lymph Node Dissection Is a Risk Factor for Permanent Hypocalcemia

BACKGROUND

Thyroidectomy is a treatment option in some benign thyroid disorders and the definitive treatment option for thyroid cancer. As postoperative mortality is extremely rare data on postoperative complications and long-term health consequences are important.

OBJECTIVE

To evaluate the frequencies of short- and long-term complications, and their risk factors in pediatric patients (0-18 years) who underwent a thyroidectomy in a tertiary children's hospital.

METHODS

A retrospective single center study was performed including all pediatric patients who underwent a thyroidectomy between January 2013 and February 2020.

RESULTS

Forty-eight patients were included in this study (mean age 14.6 years). Twenty-nine total thyroidectomies and 19 hemithyroidectomies were conducted. Thyroid carcinoma was the indication to perform a thyroidectomy in 12 patients, 36 patients underwent a thyroidectomy because of a benign thyroid disorder. Postoperative hypocalcemia was evaluated in patients who underwent a total thyroidectomy. Rapidly resolved hypocalcemia was observed in three patients (10.3%), transient hypocalcemia in 10 patients (34.5%) and permanent hypocalcemia in six patients (20.7%). Permanent hypocalcemia was only seen in patients who underwent a thyroidectomy combined with additional lymph node dissection because of thyroid carcinoma [thyroid carcinoma: OR 43.73, 95% CI (2.11-904.95); lymph node dissection: OR 76.14, 95% CI (3.49-458.98)]. Transient and permanent recurrent laryngeal nerve injury was reported in four (8.3%) and one (2.1%) of all patients, respectively.

CONCLUSION

Permanent postoperative complications after thyroidectomy are rare in pediatric patients undergoing a thyroidectomy without lymph node dissection. However, in this age group permanent hypocalcemia occurs more frequently after thyroidectomy with additional lymph node dissection because of thyroid cancer. With respect to quality of life, especially of pediatric thyroid cancer patients, reducing this complication is an important goal.

The inferior parathyroid glands preserved in site recover faster than the superior parathyroid glands preserved in site after thyroid surgery for carcinoma

Due to the great difficulty in being preserved in site for the variable positions, the inferior parathyroid glands were advised to being routinely autotransplanted to prevent permanent hypoparathyroidism. The aim of this study was to compare the performance in the function of the superior parathyroid glands preserved in site with that of the inferior parathyroid glands preserved in site.We conducted a retrospective study including patients who underwent thyroid surgery for papillary thyroid carcinoma at our department between January 2014 and June 2018. According to the number and original position of the autoplastic parathyroid gland(s), patients were divided into group 1 (1 superior parathyroid gland), group 2 (1 inferior parathyroid glands), group 3 (1 superior parathyroid gland and 1 inferior parathyroid gland) and group 4 (2 inferior parathyroid glands). The postoperative complications and serum parathyroid hormone and calcium were analyzed.A total of 368 patients were included in the study, among them 27, 243, 40, and 58 patients were divided into group 1, group 2, group 3, and group 4, respectively. Compared with those in group 2, the serum parathyroid hormones were higher at 1 week (2.98 ± 1.52 vs 2.42 ± 0.89, P = .049) and 2 weeks (3.49 ± 1.42 vs 2.8 ± 0.81, P = .019) postoperatively in group 1. There was also significantly different in the serum parathyroid hormone at 2 weeks postoperatively between group 3 and group 4 (2.95 ± 0.98 vs 2.58 ± 0.82, P = .047).The inferior parathyroid glands preserved in site recover faster than the superior parathyroid glands preserved in site.

Characteristics of hypoparathyroidism in Colombia: data from a single center in the city of Medellín

OBJECTIVE

Hypoparathyroidism is a rare condition, whose most common etiology is complications of neck surgery. The aim of the study was to identify the clinical and biochemical profile of the patients with diagnosis of hypoparathyroidism, including the frequency of symptoms, clinical signs, long-term complications and disease control. Additionally, the study sought to know what the medication profile was, and the doses required by the patients.

SUBJECTS AND METHOD

A retrospective cohort study was conducted wherein all patients with ICD-10 codes associated with hypoparathyroidism between 2011 and 2018 at the Hospital Universitario San Vicente Fundación were included. We investigated the etiology of the disease; biochemical profile including lowest serum calcium, highest serum phosphorus, 25OHD levels, calciuria and calcium/phosphorus product; medication doses, disease control, and presence of complications, especially renal and neurologic complications were also evaluated.

RESULTS

The cohort included 108 patients (99 women/9 men) with a mean age of 51.6 ± 15.6 years. The main etiology was postoperative (93.5%), the dose of elemental calcium received was relatively low (mean 1,164 mg/day), and in only 9.2% of cases more than 2,500 mg/day of elemental calcium was necessary. We were able to evaluate the follow-up in 89 patients, and found that only 57.3% met the criteria for controlled disease.

CONCLUSION

The clinical profile of patients with hypoparathyroidism in our cohort is similar to that described in other international studies, with predominantly postoperative etiology. With standard therapy, only adequate control is achieved in a little more than half of patients. Arch Endocrinol Metab. 2020;64(3):282-9.

Influence of gender and women's age on the prevalence of parathyroid failure after total thyroidectomy for multinodular goiter

Background

Female gender, particularly of a young age, has been reported as a risk factor for hypocalcemia after total thyroidectomy. There are no studies, however, addressing specifically the influence of women's age and menstrual status on postoperative parathyroid function.

Methods

Cohort study of consecutive patients undergoing total thyroidectomy for benign goiter between 2000-2017, excluding those with associated hyperparathyroidism, reoperation or conservative procedures. Prevalence of postoperative hypocalcemia (s-Ca <8 mg/dL at 24 hours), protracted (1-month) and permanent hypoparathyroidism (>1 year) were the main variables studied. Complete >1-year follow-up was achieved for all patients developing post-thyroidectomy hypocalcemia. Demographic, disease-related, number of parathyroid glands remaining in situ (PGRIS), biochemical and surgical variables were recorded. The impact of menstrual status on parathyroid function was analyzed by comparing two groups of women using a cut-off age of 45 years.

Results

A total of 811 patients were included: 14 percent were males and 86 percent females with a mean age of 53.2 years. The prevalence of postoperative hypocalcemia was ten points higher in women than in men (23.7% vs. 36.4%; P=0.008). Permanent hypoparathyroidism was more common in women than in men (5% vs. 0.9%; P=0.048). Compared to females ≥45 years, young women presented higher rates of all three parathyroid failure syndromes despite similar PGRIS scores. Age <45 years and low PGRIS scores were the only independent variables predicting postoperative hypocalcemia in females.

Conclusions

Premenopausal patients presented a higher prevalence of parathyroid failure and permanent hypoparathyroidism with similar PGRIS scores suggesting the presence of a sex-hormone factor influencing post-thyroidectomy parathyroid function.

Role of Ca²⁺ in Inhibiting Ischemia-Induced Apoptosis of Parathyroid Gland Cells in New Zealand White Rabbits

BACKGROUND Hypoparathyroidism is a common complication after thyroidectomy. Calcium supplementation can relieve these symptoms, but it is not clear whether it can protect the parathyroid glands. This study aimed to verify whether Ca²⁺ inhibits the apoptosis of parathyroid cells following ischemic injury. MATERIAL AND METHODS A rabbit model of parathyroid gland ischemic injury was established. The blood calcium concentrations were measured by colorimetry. The parathyroid hormone (PTH) levels were measured by enzyme-linked immunosorbent assay (ELISA). The parathyroid tissues were observed by hematoxylin and eosin (H&E) staining and the TdT-mediated dUTP nick-end labeling (TUNEL) assay. Western blotting was used to quantify the levels of the following proteins: caspase-3 and p38 MAP Kinase (p38 MAPK). RESULTS This study demonstrates that apoptosis can be a part of the pathological changes associated with parathyroid ischemic injury. Calcium supplementation inhibited the apoptosis of parathyroid cells following ischemic injury. There were no significant differences among the serum calcium levels from the Sham operation (Sham), the Control group (CG), or the Calcium supplementation group (CSG) after 24 h, 72 h, and 168 h of treatment. PTH levels in the CG were significantly higher than in the CSG at 24 h and 72 h after treatments. The apoptosis rate of parathyroid cells from rabbits in the CSG was significantly lower than that of those from rabbits in the CG at 24 h and 72 h after the treatment. Calcium supplementation inhibited p38 MAPK and caspase-3 expression. CONCLUSIONS This study demonstrates that calcium supplementation inhibited the apoptosis of parathyroid cells following ischemic injury.

Risk of Permanent Hypoparathyroidism After Total Thyroidectomy for Benign Disease: A Nationwide Population-based Cohort Study From Sweden

OBJECTIVE

To investigate the prevalence and risk factors for permanent hypoparathyroidism after total thyroidectomy for benign disease in a population-based setting with data independent of input of complication data.

SUMMARY OF BACKGROUND DATA

The reported rate of permanent hypoparathyroidism is highly variable and mostly rely on reported complication data from national or institutional registries.

METHODS

All patients who underwent total thyroidectomy in Sweden from 2005 to 2015 were identified through Scandinavian Quality Register for Thyroid, Parathyroid and Adrenal Surgery and the Swedish National Patient Register. Patients were matched to outcome data from the Swedish Prescribed Drug Register. Permanent hypoparathyroidism was defined as treatment with calcium and/or active vitamin D more than 1 year after surgery.

RESULTS

Seven thousand eight hundred fifty-two patients were included and 938 (12.5%) developed permanent hypoparathyroidism. The risk was lower in patients registered in the quality register (11.0% vs 16%, P < 0.001). In a multivariable analysis there was a higher risk of permanent hypoparathyroidism in patients with parathyroid autotransplantation [Odds ratio (OR) 1.72; 95% confidence interval 1.47-2.01], center-volume <100 thyroidectomies per year (OR 1.22; 1.03-1.44), age above 60 year (OR 1.64; 1.36-1.98) and female sex (OR 1.27; 1.05-1.54). Reported data from the quality register only identified 178 of all 938 patients with permanent hypoparathyroidism.

CONCLUSION

The risk of permanent hypoparathyroidism after total thyroidectomy was high and associated with parathyroid autotransplantation, higher age, female sex and surgery at a low volume center. Reported follow-up data might underestimate the rate of permanent hypoparathyroidism.