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

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

Risk assessment for hypocalcemia in therapeutic apheresis for kidney transplantation

INTRODUCTION

The increase in the number of kidney transplants performed in the United States has been paralleled with an increase in the utilization of therapeutic apheresis (TA) for kidney transplant indications. Hypocalcemia remains a significant contributor to the adverse event in TA. The magnitude of hypocalcemia and its risk factors are scarcely discussed in literature.

METHODS

This is a retrospective cohort review of adults from 18 years and above who received TA for kidney transplant-related indications from January 1, 2017 to December 31, 2022. Data extracted included basic demographics, indication for apheresis, procedure characteristics, serum ionized calcium at the mid and end of procedure and serum creatinine at the beginning of apheresis, and so forth.

RESULTS

Data from 131 patients and 860 sessions of TA were analyzed. Antibody-mediated rejection (69%) and recurrent FSGS (15%) were the leading indications for TA. There were 60 (7%) TA sessions complicated by hypocalcemia. Of these, 53 (88%) occurred in the first session, 5 (8%) occurred in second session while 2 (4%) occurred in the third and subsequent sessions. Female sex, elevated serum creatinine and use of fresh frozen plasma- are the risk factors for hypocalcemia with odd's ratio of 2.34, 7.42, and 5.01, respectively. Binary logistic regression showed that elevated serum creatinine at the commencement of therapy is an independent predictor of hypocalcemia (adjusted odd's ratio = 3.31, p = 0.001).

CONCLUSION

Hypocalcemia is prevalent in this study. Clinical vigilance and tailored procedure will avert adverse consequences.

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

OBJECTIVE

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

DATA SOURCES

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

REVIEW METHODS

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

RESULTS

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

CONCLUSIONS

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

Risk Factors for Hypoparathyroidism after Thyroid Surgery: A Single-Center Study

BACKGROUND

Hypoparathyroidism is one of the most common complications after thyroidectomy. This study evaluated the incidence and potential risk factors for postoperative hypoparathyroidism after thyroid surgical procedures in a single high-volume center.

METHODS

In this retrospective study, in all patients undergoing thyroid surgery from 2018 to 2021, a 6 h postoperative parathyroid hormone level (PTH) was evaluated. Patients were divided into two groups based on 6 h postoperative PTH levels (≤12 and >12 pg/mL).

RESULTS

A total of 734 patients were enrolled in this study. Most patients (702, 95.6%) underwent a total thyroidectomy, while 32 patients underwent a lobectomy (4.4%). A total of 230 patients (31.3%) had a postoperative PTH level of <12 pg/mL. Postoperative temporary hypoparathyroidism was more frequently associated with female sex, age < 40 y, neck dissection, the yield of lymph node dissection, and incidental parathyroidectomy. Incidental parathyroidectomy was reported in 122 patients (16.6%) and was correlated with thyroid cancer and neck dissection.

CONCLUSIONS

Young patients undergoing neck dissection and with incidental parathyroidectomy have the highest risk of postoperative hypoparathyroidism after thyroid surgery. However, incidental parathyroidectomy did not necessarily correlate with postoperative hypocalcemia, suggesting that the pathogenesis of this complication is multifactorial and may include an impaired blood supply to parathyroid glands during thyroid surgery.

Post-Thyroidectomy Hypocalcemia: Clinical Study at Tertiary Care Center

A recent review by the American association of clinical Endocrinologist (AACE) and American College of Endocrinology discussed definations and management of post-surgical hypocalcemia. In term of post-surgical hypocalcemia a total serum calcium of less than 8.5 mg/Dl(2.125 mmol/L) or ionised calcium less than 1.15 mmol/L were considered as cut off levels. The aim of the study is to evaluate & compare 30 operated cases of thyroid surgery based on its gender, age distribution, pre-operative indication & nature of surgery, post-thyroidectomy hypocalcemia. This prospective study was conducted in the Department of Otorhinolaryngology, head, neck surgery department sir T hospital, and government medical college Bhavnagar. All patients undergoing thyroidectomy surgeries were included in the study. Data collected from the patients undergoing thyroidectomise by meticulous history taking, careful clinical examination, appropriate radiological, haematological investigations including serum calcium and serum albumin, operative findings and follow-up of the cases was done after surgery for post- in association with nature of thyroid surgery. Post-thyroidectomy transient hypocalcemia is a frequent complication which can be prevented with pre-operative preparation of patients with extreme caution and pre-operative meticulous dissection, prompt identification of parathyroids and post-operative frequent monitoring of serum calcium and early treatment can prevent significant morbidity. operative hypocalcemia. The study was conducted to know the incidence of hypocalcemia after thyroid surgery.

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

INTRODUCTION

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Factors in the occurrence and restoration of hypoparathyroidism after total thyroidectomy for thyroid cancer patients with intraoperative parathyroid autotransplantation

INTRODUCTION

Postoperative hypoparathyroidism (POH) is the most common and important complication for thyroid cancer patients who undergo total thyroidectomy. Intraoperative parathyroid autotransplantation has been demonstrated to be essential in maintaining functional parathyroid tissue, and it has clinical significance in identifying essential factors of serum parathyroid hormone (PTH) levels for patients with parathyroid autotransplantation. This retrospective cohort study aimed to comprehensively investigate influential factors in the occurrence and restoration of POH for patients who underwent total thyroidectomy with intraoperative parathyroid autotransplantation (TTIPA).

METHOD

This study was conducted in a tertiary referral hospital, with a total of 525 patients who underwent TTIPA. The postoperative serum PTH levels were collected after six months, and demographic characteristics, clinical features and associated operative information were analyzed.

RESULTS

A total of 66.48% (349/525) of patients who underwent TTIPA were diagnosed with POH. Multivariate logistic regression indicated that Hashimoto's thyroiditis (OR=1.93, 95% CI: 1.09-3.42), P=0.024), the number of transplanted parathyroid glands (OR=2.70, 95% CI: 1.91-3.83, P<0.001) and postoperative blood glucose levels (OR=1.36, 95% CI: 1.06-1.74, P=0.016) were risk factors for POH, and endoscopic surgery (OR=0.39, 95% CI: 0.22-0.68, P=0.001) was a protective factor for POH. Multivariate Cox regression indicated that PTG autotransplantation patients with same-side central lymph node dissection (CLND) (HR=0.50; 95% CI: 0.34-0.73, P<0.001) demonstrated a longer time for increases PTH, and female patients (HR=1.35, 95% CI: 1.00-1.81, P=0.047) were more prone to PTH increases. Additionally, PTG autotransplantation with same-side CLND (HR=0.56, 95% CI: 0.38-0.82, P=0.003) patients had a longer time to PTH restoration, and patients with endoscopic surgery (HR=1.54, 95% CI: 1.04-2.28, P=0.029) were more likely to recover within six months.

CONCLUSION

High postoperative fasting blood glucose levels, a large number of transplanted PTGs, open surgery and Hashimoto's thyroiditis are risk factors for postoperative POH in TTIPA patients. Elevated PTH levels occur earlier in female patients and patients without CLND on the transplant side. PTH returns to normal earlier in patients without CLND and endoscopic surgery on the transplant side.

Post-thyroidectomy complications in southwestern Saudi Arabia: a retrospective study of a 6-year period

BACKGROUND

Thyroidectomy is the surgical removal of all or part of the thyroid gland for non-neoplastic and neoplastic thyroid diseases. Major postoperative complications of thyroidectomy, including recurrent laryngeal nerve injury, hypocalcemia, and hypothyroidism, are not infrequent.

OBJECTIVE

Summarize the frequency of surgical complications of thyroidectomy.

DESIGN

Retrospective.

SETTING

Secondary health facility in southwestern Saudi Arabia.

PATIENTS AND METHODS

We collected data from the records of patients who were managed for thyroid diseases between December 2013 and December 2019.

MAIN OUTCOME MEASURE

Complications following thyroidectomy.

SAMPLE SIZE

339 patients, 280 (82.6%) females and 59 (17.4%) males.

RESULTS

We found 311 (91.7%) benign and 28 (8.3%) malignant thyroid disorders. Definitive management included 129 (38.1%) total thyroidectomies, 70 (20.6%) hemithyroidectomies, 10 (2.9%) subtotal thyroidectomies and 5 (1.5%) near-total thyroidectomies with 125 (36.9%) patients treated non-surgically. The overall complication rate was 11.3%. There were 4 (1.9%) patients with recurrent laryngeal nerve palsy, 16 (7.5%) patients with temporary hypoparathyroidism, 1 (0.5%) patient with paralysis of the external branch of the superior laryngeal nerve and 3 (1.4%) patients with wound hematoma.

CONCLUSION

The rate of complications following thyroidectomy is still high. There is a need for emphasis on comprehensive measures to control the high rate of complications.

LIMITATIONS

Retrospective design and no long-term follow up to monitor late complications.

CONFLICT OF INTEREST

None.

Assessment of Serum Ionized Calcium in the Perioperative Period in Patients Undergoing Total Thyroidectomy

BACKGROUND: The serious complications of total and near-total thyroidectomy vary from hypocalcemia to recurrent laryngeal nerve injury to tension hematoma. Post-operative hypocalcemia is common and has an incidence of 1.3–83% in some studies. AIM: The aim of the study is to evaluate the immediate post-operative sequence of serum-ionized calcium next to entire or close entire thyroidectomy to describe the incidence degree of hypocalcemia. METHOD: One hundred and seventy-four (174) patients who underwent total and near-total thyroidectomy were investigated for serum-ionized calcium level preoperatively and on post-operative day (POD) 1 and 2, searching for difference in serum-ionized calcium level preoperatively. RESULTS: There was a significant difference between pre-operative serum-ionized calcium (Ca++) level and that in POD1. The mean pre-operative ionized Ca was 1.23 ± 0.47 mmol/l, while mean ionized Ca on POD1 was 1.175 ± 0.11 mmol/l proposing decrease in mean of ionized Ca++ in POD1 (p = 0.0001). There was also a significant difference between pre-operative serum-ionized Ca++ level and that in POD2. The mean pre-operative ionized Ca was 1.23 ± 0.47 mmol/l, while the mean of ionized calcium on POD2 was 1.177 ± 0.1 mmol/l suggesting decrease in mean concentration of Ca++ in POD2 (p = 0.0001). CONCLUSION: Significant number of patients who undergo near-total and total thyroidectomy develop decrease in the serum concentration of calcium postoperatively.

Risk Factors for Low Levels of Parathyroid Hormone after Surgery for Thyroid Cancer: A Single Center Study

Background: Thyroidectomy is the definitive treatment for most patients with thyroid cancer. Hypoparathyroidism is the most frequent complication of thyroidectomy, and its pathogenesis is multifactorial. The aim of this study is to evaluate the patient- and surgical-related risk factors for hypoparathyroidism after surgery for thyroid cancer. Methods: In this retrospective study, patients referred to surgery for thyroid cancer from 2016 to 2019 were enrolled. Preoperative serum calcium and parathyroid hormone (PTH) and postoperative 24 h PTH and calcium levels were evaluated. Demographic data, type of surgery, incidence of hypoparathyroidism and hypocalcemia were recorded for all the patients. Patients were divided into two groups based on post-operative PTH levels (≤12 and >12 pg/mL). Results: A total of 189 patients were enrolled in this study. There were 146 women (87.3%) and 43 men (22.7%), with a mean age of 51.3 years. A total of 79 patients (41.7%) underwent a neck dissection. A total of 59 patients (31.1%) had a postoperative PTH level < 12 pg/mL. Female sex, neck dissection, the yield of lymph node dissection and incidental parathyroidectomy were significantly associated with postoperative hypoparathyroidism. Incidental parathyroidectomy was reported in 44 (23.2%) patients and was correlated with younger age (<40 years) and neck dissection. There was no difference in the rate of post-operative hypocalcemia between patients with incidental parathyroidectomy and those without. Conclusions: Young patients undergoing neck dissection and with incidental parathyroidectomy have the highest risk of postoperative hypoparathyroidism after surgery for thyroid cancer. However, a large proportion of patients without incidental parathyroidectomy may have temporary hypocalcemia, suggesting that impaired blood supply of parathyroid glands during their identification and dissection may play a relevant role.

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.

Role of perioperative parathormone hormone level assay after total thyroidectomy as a predictor of transient and permanent hypocalcemia: Prospective study

Background

The researchers are trying to evaluate the measurement of: Intact parathyroid hormone (iPTH) and serum total calcium (sCa) levels for predicting hypocalcemia after total thyroidectomy (TT).

Methods

The sample of this single center prospective study consists of (100) patients, where (77) females and (23) males with an age range between (28) and (65) (the mean level is, 48.17 ± 6.54). These selected patients underwent total thyroidectomy (TT) in the general surgery department, Benha university hospital from the period of June 2019 to February 2020. Levels of sCa and iPTH were measured aat several times preoperatively, 10 min, 48 h, 3, 6, 9 months, and 1 year after being after gone TT.

Results

Among the entire study sample, 23 patients (23%) developed transient hypoparathyroidism and hypocalcemia (˂8.5 mg/dl), none of them developed permanent hypoparathyroidism and hypocalcemia. The cut-off point of PTH has been 10 min after TT was at 23 pg/mL as it was the best compromise between sensitivity and specificity for predicting hypocalcaemia. It has been found that Patients who have a PTH greater than 23 pg/mL can be discharged safely after 24 h. Patients who have PTH of less than 23 pg/mL were observed for an additional 24 h, and the study found that timely treatment initiation is recommended. A PTH ˂ 10 pg/mL measured at 48 h after surgery had a sensitivity, specificity as well as an accuracy of 100%, for predicting hypocalcemia after TT. The accuracy of a single PTH concentration at 48 h was useful for predicting hypocalcemia [Area under receiver–operator characteristic curve (AUC) 1; confidence interval (CI), 95%, 0.85–0.94].

Conclusion

Patients with iPTH ˂ 10 pg/mL, and sCa levels ˂ 7.4 mg/dL are at higher risk of developing hypoparathyroidism and hypocalcemia after TT.

•

Incidence of Post-thyroidectomy transient hypoparathyroidism ranges between 0.3 and 49%, while permanent hypoparathyroidism is 13%.

•

Incidence of hypocalcemia following total thyroidectomy ranging between 3% and 40% and is usually transient, while permanent hypocalcemia is ≤ 2%.

•

Post-thyroidectomy PTH accurately predict hypocalcemia.

Hypoparathyroidism: Consequences, economic impact, and perspectives. A case series and systematic review

BACKGROUND

Postoperative hypoparathyroidism (PH) is the most common complication after total thyroidectomy. Incidence varies from 2% to 83%, depending on the definition.

OBJECTIVE

We performed a systematic review of the literature to determine the medico-economic effects of PH and update understanding of long-term consequences, morbidity, and quality of life related to hypoparathyroidism.

METHODS

We considered relevant articles published between 2000 and 2020 concerning long-term consequences of PH and quality of life. All studies concerning the medico-economic assessment of PH were included. We compared data from 2018 to results in the literature.

RESULTS

A proportion of 64/403 (16.8%) patients presented with transient PH during 2018, and 7/403 (1.7%) had permanent PH. Seven patients needed supplementation with alfacalcidol at 6-month follow-up. Factors predicting the need for alfacalcidol were age <45, thyroidectomy for goiter, and lymph node dissection. Additional therapy costs related to PH were €9781.10, and additional hospital costs were €230,400. We qualitatively synthesized 41 studies. Most were retrospective studies and only a few reported costs. No series assessed direct or indirect costs of postoperative PH.

CONCLUSION

To our knowledge, no previous studies reported the medico-economic impact of PH. Decreasing PH associated with fluorescence usage should be considered, particularly concerning cost-effectiveness.

Risks and prediction of postoperative hypoparathyroidism due to thyroid surgery

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

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.

A Meta-Analysis of Risk Factors for Transient and Permanent Hypocalcemia After Total Thyroidectomy

Background

As hypocalcemia is the most common complication of total thyroidectomy, identifying its risk factors should guide prevention and management. The purpose of this study was to determine the risk factors for postthyroidectomy hypocalcemia.

Methods

We searched PubMed, Web of Science and EMBASE through January 31, 2019, and assessed study quality using the Newcastle–Ottawa Scale.

Results

Fifty studies with 22,940 patients met the inclusion criteria, of which 24.92% (5716/22,940) had transient hypocalcemia and 1.96% (232/11,808) had permanent hypocalcemia. Significant (P < 0.05) predictors of transient hypocalcemia were: younger age, female, parathyroid autotransplantation (PA), inadvertent parathyroid excision (IPE), Graves’ disease (GD), thyroid cancer, central lymph node dissection, preoperative severe Vitamin D deficiency, preoperative Vitamin D deficiency and a lower postoperative 24 h parathyroid hormone (PTH) level. Preoperative magnesium, preoperative PTH and Hashimoto’s thyroiditis were not significant predictors of transient hypocalcemia. IPE, GD, and thyroid cancer were associated with an increased rate of permanent hypocalcemia, but gender and PA did not predict permanent hypocalcemia.

Conclusion

Important risk factors for transient and permanent hypocalcemia were identified. However, given the limited sample size and heterogeneity of this meta-analysis, further studies are required to confirm our preliminary findings.

Risk factors and effects of hypocalcemia prior to discharge following thyroidectomy

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

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.

Outcomes of parathyroid gland identification and autotransplantation during total thyroidectomy

PURPOSE

To report the outcomes of parathyroid gland (PG) identification and autotransplantation (autoT) during thyroidectomy.

METHODS

Consecutive total thyroidectomy cases performed by a single surgeon using extracapsular dissection technique were considered. PGs were not intentionally sought during dissection. PG location, number identified and autoT were prospectively recorded and correlated to postoperative outcomes.

RESULTS

In all, 265 cases were included. The mean number of PGs identified per case was 2.7. The number of PGs identified had no correlation to postoperative hypocalcemia. However, independent risk factors for hypocalcemia were female sex, bilateral central compartment neck dissection (CND) and autoT > 1 PG; and for permanent hypoparathyroidism were female sex and bilateral CND. AutoT did not protect against permanent hypoparathyroidism.

CONCLUSION

The number of PGs identified during the course of a standard extracapsular dissection technique had no correlation to postoperative hypocalcemia. Whenever possible, avoiding bilateral CND and careful techniques to preserve PGs in an in situ and viable state, to obviate the necessity for autoT, are recommended.

Parathyroid Hormone Reduction Predicts Transient Hypocalcemia after Total Thyroidectomy: A Single-Center Prospective Study

OBJECTIVE

We performed this study to investigate the risk factors for postoperative hypocalcemia after total thyroidectomy with central lymph node dissection (CLND). Study Design. This was a single-center prospective study based on 176 consecutive patients who underwent total thyroidectomy for papillary thyroid carcinoma. Setting. Patients were recruited between January 2016 and June 2018. Subjects and Methods. Patients who underwent bilateral (n = 155, bilateral group) and ipsilateral CLND (n = 21) after total thyroidectomy were included. The preoperative and postoperative parathyroid hormone (PTH) and calcium levels were detected. The risk factors for transient hypocalcemia were identified using logistic regression analysis and receiver operating characteristic (ROC) curve analysis.

RESULTS

Fifty-one (28.98%) patients developed transient hypocalcemia, and 2 patients (1.14%) developed permanent hypoparathyroidism. There was no difference in the gender ratio or the morbidity of hypocalcemia between the patients who underwent bilateral and ipsilateral CLND. On postoperative day 1, PTH decrease was a risk factor for transient hypocalcemia in the whole cohort (β = 0.043, OR = 1.044, 95% CI 1.023-1.065, p < 0.001), bilateral group (β = 0.042, OR = 1.043, 95% CI 1.022-1.064, p < 0.001), and female patients (β = 0.049, OR = 1.050, 95% CI 1.026-1.075, p < 0.001). Tumor diameter was a risk factor for transient hypocalcemia in female patients (β = 0.499, OR = 1.647, 95% CI 1.003-2.704, p=0.049). The ROC curve analysis illustrated that 65.58%, 71.00%, and 71.00% PTH level reduction had high accuracy in predicting transient hypocalcemia in the whole cohort, bilateral group, and female patients, respectively (AUC = 0.986, 0.987, and 0.987).

CONCLUSION

Asymptomatic female patients with bilateral CLND and a 71.00% PTH level reduction were at a high risk of transient hypocalcemia.

Severe Hypocalcemia After Thyroidectomy: An Analysis of 7366 Patients

OBJECTIVE

The aim of the study was to determine severe hypocalcemia rate following thyroidectomy and factors associated with its occurrence.

BACKGROUND

Hypocalcemia is the most common complication after thyroidectomy. Severe post-thyroidectomy hypocalcemia can be life-threatening; data on this specific complication are scarce.

METHODS

Patients who underwent thyroidectomy in the American College of Surgeons-National Surgical Quality Improvement Program thyroidectomy-targeted database (2016-2017) were abstracted. A severe hypocalcemic event was defined as hypocalcemia requiring intravenous calcium, emergent clinic/hospital visit, or a readmission for hypocalcemia. Multivariable regression was used to identify factors independently associated with occurrence of severe hypocalcemia.

RESULTS

Severe hypocalcemia occurred in 5.8% (n = 428) of 7366 thyroidectomy patients, with 83.2% necessitating intravenous calcium treatment. Rate of severe hypocalcemia varied by diagnosis and procedure (0.5% for subtotal thyroidectomy to 12.5% for thyroidectomy involving neck dissections). Overall, 38.3% of severe hypocalcemic events occurred after discharge; in this subset, 59.1% experienced severe hypocalcemia despite being discharged with calcium and vitamin D. Severe hypocalcemia patients had higher rates of recurrent laryngeal nerve injury (13.4% vs 6.6%), unplanned reoperations (4.4% vs 1.3%), and longer hospital stay (30.4% vs 6.2% ≥3 days (all P < 0.01). After multivariate adjustment, severe hypocalcemia was associated with multiple factors including Graves disease [odds ratio (OR) = 2.06], lateral neck dissections (OR: 3.10), and unexpected reoperations (OR = 3.55); all P values less than 0.01.

CONCLUSIONS

Severe hypocalcemia and suboptimal hypocalcemia management after thyroidectomy are common. Patients who experienced severe hypocalcemia had higher rates of nerve injury and unexpected reoperations, indicating surgical complexity and provider inexperience. More biochemical surveillance particularly a parathyroid hormone-based protocol, fine-tuned supplementation, and selective referral could reduce occurrence of this morbid complication.

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.

Postoperative hypocalcemia: analysis of factors influencing early hypocalcemia development following thyroid surgery

BACKGROUND

Early Hypocalcemia is the most frequent complication after thyroid surgery. Several studies have tried to identify factors (patient caracteristics or surgical technique variations) affecting hypocalcemia following thyroid surgery. This studiy evaluates the role of several factors in postoperative hypocalcemia development.

METHODS

A retrospective study conducted on 2108 patients that underwent thyroid surgery in a single center (1669 women and 439 men). Postoperative early hypocalcemia was defined as serum calcium levels lower than 8,0 mg/dl measured 24 h after surgery. Following factors were evaluated in the study: sex, age, glandular hyperfunction, preoperative diagnosis, preoperative serum calcium levels, preoperative serum PTH levels, type of surgery performed (total thyroidectomy vs. lobectomy); minimally invasive video assisted thyroidectomy (MIVAT); number of parathyroid preserved in situ, postoperative serum calcium levels, changes in perioperative calcium levels (difference between preoperative values ​​and postoperative calcium levels), presence of carcinoma in the surgical specimen, presence of thyroiditis based on histopatology reports.

RESULTS

Among evaluated factors only gender and surgical procedure revealed to be significantly correlated to early hypocalcemia development. In fact female patients experienced postoperative hypocalcemia in 42% (701/1669) of cases, which was signicantly higher than the 21.4% (94/439) identified in men. We also noticed a greater hypocalcemia incidence in patient undergoing total thyroidectomy (38.8%) than in patient undergoing lobectomy group (13.8%). Early hypocalcemia development didn't appear to be related to preoperative serum calcium levels but it showed a statistically significant correlation with perioperative serum calcium level drop.

CONCLUSION

This findings suggest that sex (female gender is a strong risk factor),surgical procedure and perioperative changes in serum calcium are the only factors (among all variables examined) that influence early hypocalcemia development.

Huge variations in definition and reported incidence of postsurgical hypoparathyroidism: a systematic review

PURPOSE

The reported incidence of post surgical hypoparathyroidism (HypoPT) varies greatly. Previous research suggests that the definition of HypoPT is not consistent in the literature. We therefore conducted a systematic review to investigate how HypoPT is defined and whether this definition, as well as the selected threshold for hypocalcemia affects the incidence.

METHODS

Using a predefined search string we identified all articles in PubMed reporting on the incidence of postsurgical HypoPT from 1st January 2010 to January 2017.

RESULTS

We identified 89 articles that employed 20 different definition of HypoPT. The incidence of HypoPT varied from 0.0% to 20.2%. The definitions were not associated with incidence of HypoPT. Use of prophylactic post-operative calcium supplements, however decreased the risk of HypoPT (p = 0.03), and there was a trend towards a lower risk of HypoPT when using a definition of hypocalcemia below lower limit of the reference range (p = 0.09).

CONCLUSION

The large number of definitions of HypoPT, as well as the huge variation in incidence point to a problem suggests that the awareness of HypoPT should be raised. Use of prophylactic post-operative calcium supplements may decrease risk of HypoPT. This, however, may be due to reverse causality as awareness of the risk of HypoPT may promote the use of calcium supplementation.

Routine low-dose calcium supplementation after thyroidectomy does not reduce the rate of symptomatic hypocalcemia: a prospective randomized trial

Purpose

Routine supplementation of high-dose calcium significantly decreased the risk of postoperative symptomatic hypocalcemia after thyroidectomy. However, there is an ongoing debate about whether the same results can be achieved with low-dose calcium supplementation.

Methods

Patients (n = 138) who underwent total thyroidectomy for thyroid cancer were 1:1 randomly assigned to receive oral supplements of 1,500 mg/day elemental calcium and 1,000 IU/day cholecalciferol for 2 weeks or no supplementation. Primary objective was to compare the incidence of symptomatic hypocalcemia for 3 days after total thyroidectomy. Secondary objective was to find the predictors for postoperative hypocalcemia in patients with thyroid cancer.

Results

Sixty-five patients in the calcium group and 69 patients in the control group were finally analyzed. The incidence of symptomatic hypocalcemia showed no difference between the calcium and control group (32.3% vs. 21.7%, P = 0.168). The total dosage of intravenous calcium (593.4 ± 267.1 mg vs. 731.6 ± 622.7 mg, P = 0.430) administered to patients with symptomatic hypocalcemia was also comparable between groups. In a multivariate analysis, parathyroid hormone level of 13 pg/mL at postoperative day 1 was only predictive for symptomatic hypocalcemia, and its incidence was 20.9 times (95% confidence interval, 6.8-64.5) higher in patients with parathyroid hormone <13 pg/mL. Other factors did not predict the development of hypocalcemia, including clinicopathological features and routine supplementation of low-dose calcium.

Conclusion

Routine low-dose calcium supplementation did not reduce the risk of postoperative hypocalcemia. Patients who may benefit from calcium supplementation should be carefully selected.

Predictors of postoperative hypocalcemia occurring after a total thyroidectomy: results of prospective multicenter study

BACKGROUND

Thyroid surgeries are among the most common operations performed in the world. Hypocalcemia following total thyroidectomy is a common complication that is sometimes difficult to correct. The aim of this study is to determine the risk factors for hypocalcemia following total thyroidectomy and their clinical value.

METHODS

From January 2015 through to April 2017, 400 patients were included in this prospective multicenter study. All patients underwent total thyroidectomy due to various thyroid diseases. The following risk factors were analyzed: pre-operative and post-operative biochemical blood parameters, clinical effects and factors related to surgery, the patient, and the disease.

RESULTS

Post-operative hypocalcemia developed in 257 patients (64.2%). Of them, 197 patients (76.7%) were diagnosed with asymptomatic hypocalcemia. Clinical symptoms were present in 60 of the 257 patients with hypocalcemia (23.3%). The statistically significant predictors of hypocalcemia were decreased calcium and ionized calcium pre-operatively (p < 0.001), parathyroid hormone on day one following surgery (p < 0.001), thyrotoxicosis <10 years before surgery (odds ratio 1.65, 95% CI 1.01-2.70, p = 0.046), the number of parathyroid glands found during surgery (odds ratio 0.52, 95% CI 0.38-0.70, p < 0.001), ligation of the trunk of the left inferior thyroid artery (odds ratio 2.04, 95% CI 1.27-3.29, p = 0.003), ligation of the trunk of the right inferior thyroid artery (odds ratio 2.37, 95% CI 1.47-3.81, p < 0.001), and the number of transplanted parathyroid glands (odds ratio 1.87, 95% CI 1.12-2.97, p = 0.015). In the multivariate analysis, age (odds ratio 1.05, 95% CI 1.01-1.09, p = 0.029) and gender (odds ratio 5.94, 95% CI 1.13-31.26, p = 0.035) were statistically significant predictors.

CONCLUSIONS

This study demonstrates that there is a number of different patient (gender, age, and duration of thyrotoxicosis <10 years before surgery) and surgical (number of parathyroid glands found during surgery, decreased calcium and ionized calcium before surgery, parathyroid hormone on day one following surgery, and ligation of the trunk of the left and right inferior thyroid artery) risk factors predictive of hypocalcemia following total thyroidectomy. Optimization of the surgical technique could possibly prevent the occurrence of hypocalcemia after total thyroidectomy in some cases; in other cases, identification of known risk factors post-operatively could permit early detection and effective treatment of these patients.

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

BACKGROUND AND OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Risk factors for hypocalcemia and hypoparathyroidism following thyroidectomy: a retrospective Chinese population study

Background

Hypocalcemia is one of the most common postoperative complications following thyroid surgery in clinical practice. The occurrence of hypocalcemia is mainly attributed to hypoparathyroidism when parathyroid glands are devascularized, injured, or dissected during the surgery. The aim of this study was to analyze the risk factors for hypocalcemia and hypoparathyroidism following thyroidectomy.

Patients and methods

A total of 278 patients who underwent thyroid surgery were analyzed retrospectively. Univariate analysis and multivariable logistic regression were performed to discover the risk factors for hypocalcemia and hypoparathyroidism.

Results

Postoperative hypocalcemia occurred in 76 (27.3%) patients and hypoparathyroidism occurred in 42 (15.1%) patients. Seven factors were significantly related to the presence of postoperative hypocalcemia, namely, age (P=0.049), gender (P=0.015), lateral lymph node dissection (P=0.017), operation type (P<0.001), preoperative parathyroid hormone (PTH) level (P=0.035), operation time (P=0.001), and applying carbon nanoparticles (CNs; P=0.007). Our result revealed that gender (P=0.014), lateral lymph node dissection (P=0.038), operation type (P<0.001), operative time (P<0.001), and applying CNs (P=0.001) had a significant correlation with postoperative hypoparathyroidism.

Conclusion

These findings were crucial for guiding surgeons to prevent the occurrence of hypocalcemia and hypoparathyroidism.

Parathyroid hormone and serum calcium levels measurements as predictors of postoperative hypocalcemia in total thyroidectomy

Background

The rules of quantitative measures such as parathyroid hormone (PTH) levels in the first hours following total thyroidectomy have since been validated repeatedly. Such measures play an integral rule in identifying patients at significant risk for hypocalcaemia and have allowed for earlier supplementation of these patients with calcium with or without vitamin D.

Methods

A retrospective analysis was conducted of 40 consecutive patients with well differentiated thyroid cancer (WDTC) who underwent total thyroidectomy without central neck dissection (CND) as an initial surgery and no comorbidity at King Abdulaziz Medical City (National Guard hospital), between July 2011 and July 2012. A blood testing protocol was applied for all patients that measured serum calcium PTH at 6 hours postoperatively.

Results

Following total thyroidectomy, women were found to experience transient hypocalcaemia in 12.5% of cases (4/32), whereas no men cases encountered this postoperative complication (0/8). However, most probably due to small sample size, this difference was not statistically significant. PTH level was significantly associated with post thyroidectomy hypocalcaemia (43.7±39.3 versus 13.40±24.9 ng/L), P=0.014. Only negligible differences in the length of hospital stay were observed with and without post-thyroidectomy hypocalcaemia.

Conclusions

Using post-thyroidectomy PTH levels to predict hypocalcaemia has been confirmed in the current study. So, the use of PTH levels allows for early risk stratification of our patients and we feel this has resulted in better patient satisfaction.

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

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

Hypomagnesemia predicts postoperative biochemical hypocalcemia after thyroidectomy

Background

To investigate the role of magnesium in biochemical and symptomatic hypocalcemia, a retrospective study was conducted.

Methods

Less-than-total thyroidectomy patients were excluded from the final analysis. Identified the risk factors of biochemical and symptomatic hypocalcemia, and investigated the correlation by logistic regression and correlation test respectively.

Results

A total of 304 patients were included in the final analysis. General incidence of hypomagnesemia was 23.36%. Logistic regression showed that gender (female) (OR = 2.238, p = 0.015) and postoperative hypomagnesemia (OR = 2.010, p = 0.017) were independent risk factors for biochemical hypocalcemia. Both Pearson and partial correlation tests indicated there was indeed significant relation between calcium and magnesium. However, relative decreasing of iPTH (>70%) (6.691, p < 0.001) and hypocalcemia (2.222, p = 0.046) were identified as risk factors of symptomatic hypocalcemia. The difference remained significant even in normoparathyroidism patients.

Conclusions

Postoperative hypomagnesemia was independent risk factor of biochemical hypocalcemia. Relative decline of iPTH was predominating in predicting symptomatic hypocalcemia.

Outcomes of Parathyroid Autotransplantation During Total Thyroidectomy: A Comparison with Age- and Sex-Matched Controls

PURPOSE

To determine the effect of parathyroid autotransplantation (PA) on postoperative hypocalcemia in cases of total thyroidectomy.

MATERIALS AND METHODS

Cases undergoing total thyroidectomy and PA were compared with age and sex-matched controls who had not undergone PA. The postoperative percentage changes (PC) of parathyroid hormone (PTH) and calcium (Ca+2) in the first 12-24 hours (12-24hr→preop), between the 1st-3rd weeks (1-3wk→preop) and at the 6th month (6mo→preop), the rates of hypocalcemia (Ca+2< 8mg/dL) and low PTH level (PTH< 15 pg/mL), permanent hypocalcemia, inadvertent parathyroidectomy in both groups were compared.

RESULTS

The number of patients with PTH12-24hr<15 pg/mL was significantly higher (n:34,(55.7%)) than the number of patients in the control group (n:16(26.2%)), (p=0.001). The rate of decrease in the blood Ca+2 median PC (6mo→preop) was significantly higher in the PA group (4.2%) than the control group (1.1%), (p=0.008). There was no significant difference between the 2 groups in terms of the postoperative frequency of hypocalcemia (p>0.05). In the PA&age≤50 group, the rate of inadvertent parathyroidectomy was higher than that of cases over age 50 (p=0.029).

CONCLUSION

In spite of the presence of an increased postoperative hypocalcemia trend in cases requiring PA during total thyroidectomy, the rates of transient and permanent hypocalcemia were not different to the control cases. But the frequency of cases with low PTH level in cases undergoing PA was higher than that of the control cases. In cases of 50 years of age and under, who had undergone PA, the possibility of inadvertent parathyroidectomy increased.

Predictors and risk factors of hypoparathyroidism after total thyroidectomy

BACKGROUND

The aim of this study was to evaluate the risk factors for hypoparathyroidism after total thyroidectomy and to determine whether early postoperative serum levels of calcium and phosphorus could be used to predict its development.

MATERIALS AND METHODS

The study group consisted of 1030 patients who had undergone total thyroidectomy at our institution between March 2008 and July 2014. The clinicopathologic characteristics, indications for the operation, and surgical details of normocalcemic and hypocalcemic patients were compared, and variations in serum calcium and phosphorus levels were measured every day after the operation.

RESULTS

Of the 1030 patients, 291 (28.2%) were found to have transient hypocalcemia and 27 (2.6%) had permanent hypocalcemia. On univariate analysis, younger age (P = 0.001), female gender (P < 0.001), longer operative time (P = 0.009), extent of central neck dissection (CND) (P = 0.003), and malignancy (P = 0.005) were found to be significantly associated with transient hypocalcemia. On multivariate analysis, female gender (P = 0.001), extent of CND (P = 0.017), and the identification of parathyroid gland (PTG) tissue in permanent pathologic sections were significant factors. In addition, the occurrence of postoperative hypocalcemia was correlated with relative changes in serum calcium and phosphorus levels. Patients whose serum calcium levels decreased over 20% on postoperative day 2 were more likely to develop hypoparathyroidism, with 92% specificity.

CONCLUSION

Female gender (P = 0.001), extent of CND (P = 0.014), and PTG in permanent pathologic sections (P = 0.035) were found to be significant factors affecting the development of hypocalcemia. Despite some study limitations, we suggest that the relative changes in the serum levels of calcium (20%) and of phosphorus (40%) on the second postoperative day may be reliable predictors of post-thyroidectomy hypoparathyroidism.

Can Total Thyroidectomy Be Safely Performed by Residents?: A Comparative Retrospective Multicenter Study

This retrospective comparative multicenter study aims to analyze the impact on patient outcomes of total thyroidectomy (TT) performed by resident surgeons (RS) with close supervision and assistance of attending surgeons (AS).All patients who underwent TT between 2009 and 2013 in 10 Units of endocrine surgery (8 in Italy, 1 in France, and 1 in UK) were evaluated. Demographic data, preoperative diagnosis, extension of goiter, type of surgical access, surgical approach, operative time, use and duration of drain, length of hospitalization, histology, and postoperative complications were recorded. Patients were divided into 3 groups: A, when treated by an AS assisted by an RS; B and C, when treated by a junior and a senior RS, respectively, assisted by an AS.The 8908 patients (mean age 51.1 ± 13.6 years), with 6602 (74.1%) females were enrolled. Group A counted 7092 (79.6%) patients, Group B 261 (2.9%) and Group C 1555 (17.5%). Operative time was significantly greater (P < 0.001) in B (101.3 ± 43.0 min) vs A (71.8 ± 27.6 min) and C (81.2 ± 29.9 min). Duration of drain was significantly lower (P < 0.001) in A (47.4 ± 13.2 h) vs C (56.4 ± 16.5 h), and in B (42.8 ± 14.9 h) vs A and C. Length of hospitalization was significantly longer (P < 0.001) in C (3.8 ± 1.8 days) vs B (2.4 ± 1.0 days) and A (2.6 ± 1.5 days). No mortality occurred. Overall postoperative morbidity was 22.3%: it was significantly higher in B vs A (29.5% vs 22.3%; odds ratio [OR] 1.46, 95% confidence interval [CI] 1.11-1.92, P = 0.006) and C (21.3%; OR 1.55, 95% CI 1.15-2.07, P = 0.003). No differences were found for recurrent laryngeal nerve palsy, hypoparathyroidism, hemorrhage, and wound infection. The adjusted ORs in multivariate analysis showed that overall morbidity remained significantly associated with Group B vs A (OR 1.48, 95% CI 1.12-1.96, P = 0.005) and vs C (OR 1.60, 95% CI 1.19-2.17, P = 0.002), while no difference was observed in Group A vs B + C.TT can be safely performed by residents correctly supervised. Innovative gradual training in dedicated high-volume hospitals should be proposed in order to allow adequate autonomy for the RS and safeguard patient outcome.

Importance of in situ preservation of parathyroid glands during total thyroidectomy

Background

Parathyroid failure is the most common complication after total thyroidectomy but factors involved are not completely understood. Accidental parathyroidectomy and parathyroid autotransplantation resulting in fewer than four parathyroid glands remaining in situ, and intensity of medical treatment of postoperative hypocalcaemia may have relevant roles. The aim of this study was to determine the relationship between the number of parathyroid glands remaining in situ and parathyroid failure after total thyroidectomy.

Methods

Consecutive patients undergoing first-time total thyroidectomy were studied prospectively, recording the number of Parathyroid Glands Remaining In Situ (PGRIS = 4 − (glands autografted + glands in the specimen)) and the occurrence of postoperative hypocalcaemia, and protracted and permanent hypoparathyroidism. Demographic, disease-related, laboratory and surgical variables were recorded. Patients were classified according to the PGRIS number into group 1–2 (one or two PGRIS), group 3 (three PGRIS) and group 4 (all four glands remaining in situ), and were followed for at least 1 year.

Results

A total of 657 patients were included, 43 in PGRIS group 1–2, 186 in group 3 and 428 in group 4. The prevalence of hypocalcaemia, and of protracted and permanent hypoparathyroidism was inversely related to the PGRIS score (group 1–2: 74, 44 and 16 per cent respectively; group 3: 51·1, 24·7 and 6·5 per cent; group 4: 35·3, 13·1 and 2·6 per cent; P &lt; 0·001). Intact parathyroid hormone concentrations at 24 h and 1 month were inversely correlated with PGRIS score (P &lt; 0·001). Logistic regression identified PGRIS score as the most powerful variable influencing acute and chronic parathyroid failure. In addition, a normal–high serum calcium concentration 1 month after thyroidectomy influenced positively the recovery rate from protracted hypoparathyroidism in all PGRIS categories.

Conclusion

In situ parathyroid preservation is critical in preventing permanent hypoparathyroidism after total thyroidectomy. Active medical treatment of postoperative hypocalcaemia has a positive synergistic effect.

The Cost of Prolonged Hospitalization due to Postthyroidectomy Hypocalcemia: A Case-Control Study

The aim of this study is to evaluate the additional costs associated with calcium monitoring and treatment as well as evaluate the incidence and predictors of postthyroidectomy hypocalcemia. Methods. This case-control study involved thyroidectomy and completion thyroidectomy patients operated on between January 2012 and August 2013. Cases were defined as requiring calcitriol supplementation, and controls did not require supplementation. Patient (age, sex), nodule (cytology, pathology), surgical data (neck dissection, parathyroid identification, and reimplantation), and hospital stay (days hospitalized in total and after drain removal) were compared. Comparisons were made using t-tests and chi-square tests with an alpha of 0.05. The estimated cost associated with the extended stay was then compared with the cost of supplementation. Results. A total of 191 patients were evaluated (61 cases and 130 controls). Predictors of hypocalcemia include female age, neck dissection, and parathyroid reimplantation. Hypocalcemic patients were hospitalized for a longer period of time after drain removal (2.5 versus 0.8 days, P<0.001), and hospitalization costs after neck drain removal were higher in this group as well (8,367.32$ versus 2,534.32$, P<0.001). Conclusion. Postoperative hypocalcemia incurs significant additional health care costs at both the local and health care system levels.

Prolonged duration of surgery is not a risk factor for postoperative complications in patients undergoing total thyroidectomy: a single center experience in 305 patients

Background

Hypocalcemia and nerve injury are the most severe complications after thyroid surgery. The duration of surgery has not been previously considered as a risk factor for postoperative complications in patients undergoing total thyroidectomy. We sort to investigate the influence of prolonged surgery on postoperative complications in patients undergoing total thyroidectomy.

Methods

We hypothesized that a threshold of > 120 minutes of surgical time could represent a surrogate marker for postoperative complications in patients undergoing total thyroidectomy for benign thyroid disorders. The study population was divided into two groups based on the median duration of surgery (120 min): group I ≤ 120 minutes (control group), group II > 120 minutes (study group). The charts of eligible patients undergoing total thyroidectomy within a six-year period from January 1^st 2006 to December 31^st 2012 were reviewed. The primary outcomes included the rates postoperative hypocalcemia and recurrent laryngeal nerve palsy. The secondary outcomes included the rates of postoperative hemorrhage, wound dehiscence and length of hospital stay.

Results

305 cases of thyroidectomy were included for analysis; 130 (42.6%) control group and 175 (57.4%) study group. Transient (15.4% vs 19.4%) and permanent (3.8% vs. 2.9%) hypocalcemia were recorded in control and study group respectively. The incidence of nerve palsy was 1.5% in the control group and 1.4% in the study group. The mean length of postoperative hospital stay was 3d in both groups. There was no significant difference amongst both groups with regard to postoperative bleeding (p = 0.57) and wound dehiscence (p = 0.31). Prolonged surgery (> 120 min) was not identified as a risk factor for increased postoperative complication.

Conclusion

Prolonged duration of surgery > 120 minutes is not a surrogate marker for postoperative complications in patients undergoing total thyroidectomy.

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

Postoperative hypocalcemia is the most frequent complication of total thyroidectomy. It may have a delayed onset, and therefore delays the discharge from the hospital, requiring calcium replacement therapy to alleviate clinical symptoms. During a 7-month period, 2,631 consecutive patients undergoing primary or completion thyroidectomy were prospectively followed up and underwent analysis regarding postoperative hypoparathyroidism. Data were prospectively collected by questionnaires from 39 Italian endocrine surgery units affiliated to the Italian Endocrine Surgery Units Association (Club delle Unità di EndocrinoChirurgia-UEC), where thyroid surgery is routinely performed. The incidence of hypoparathyroidism was 28.8 % (757 patients), including transient hypocalcemia (27.9 %-734 patients) and permanent hypocalcemia (0.9 %-23 patients). The rate of asymptomatic hypocalcemia was 70.80 %. The incidence of permanent hypocalcemia was higher in the symptomatic hypocalcemia group (7.5 %) than in asymptomatic one (1.5 %). Female patients experienced a transient postoperative hypocalcemia more frequently than male patients (29.7 and 21.2 %, respectively; p < 0.0001). The percentage developing hypocalcemia in patients in which parathyroid glands were intraoperatively identified and preserved was higher than in the patients in which the identification of parathyroid glands was not achieved (29.2 vs. 18.7 %, p < 0.01). This prospective study confirmed the main risk factors for postoperative hypocalcemia: thyroid cancer, nodal dissection, and female gender. It farther showed that identifying parathyroids has an important role to prevent permanent hypocalcemia though with a higher risk of transient hypocalcemia. A suitable informed consent should especially emphasize the importance of some primary factors in increasing the risk of hypocalcemia after thyroid surgery.

Systematic review and meta-analysis of predictors of post-thyroidectomy hypocalcaemia

BACKGROUND

Hypocalcaemia is common after thyroidectomy. Accurate prediction and appropriate management may help reduce morbidity and hospital stay. The aim of this study was to perform a systematic literature review and meta-analysis of predictors of post-thyroidectomy hypocalcaemia.

METHODS

A systematic search of PubMed, EMBASE and the Cochrane Library databases was undertaken, and the quality of manuscripts assessed using a modified Newcastle-Ottawa Scale.

RESULTS

Some 115 observational studies were included. The median (i.q.r.) incidence of transient and permanent hypocalcaemia was 27 (19-38) and 1 (0-3) per cent respectively. Independent predictors of transient hypocalcaemia included levels of preoperative calcium, perioperative parathyroid hormone (PTH), preoperative 25-hydroxyvitamin D and postoperative magnesium. Clinical predictors included surgery for recurrent goitre and reoperation for bleeding. A calcium level lower than 1·88 mmol/l at 24 h after surgery, identification of fewer than two parathyroid glands (PTGs) at surgery, reoperation for bleeding, Graves' disease and heavier thyroid specimens were identified as independent predictors of permanent hypocalcaemia in multivariable analysis. Factors associated with transient hypocalcaemia in meta-analyses were inadvertent PTG excision (odds ratio (OR) 1·90, 95 per cent confidence interval 1·31 to 2·74), PTG autotransplantation (OR 2·03, 1·44 to 2·86), Graves' disease (OR 1·75, 1·34 to 2·28) and female sex (OR 2·28, 1·53 to 3·40).

CONCLUSION

Perioperative PTH, preoperative vitamin D and postoperative changes in calcium are biochemical predictors of post-thyroidectomy hypocalcaemia. Clinical predictors include female sex, Graves' disease, need for parathyroid autotransplantation and inadvertent excision of PTGs.