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

Evaluating the effectiveness of dual dye combination of indocyanine green and carbon nanoparticles with parathyroid hormone test in preserving parathyroid gland during papillary thyroid cancer surgery: a single-center retrospective cohort study

Preserving the integrity of parathyroid glands is crucial in papillary thyroid cancer (PTC) surgery to avoid hypoparathyroidism. In recent years, two novel dyes, activated carbon nanoparticles (CNP) and indocyanine green (ICG), have been utilized to assist in parathyroid gland identification. However, the use of CNP or ICG alone can result in extravasation of dye or excessive fluorescence of non-parathyroid tissue, which can affect the accuracy of surgical outcomes by yielding false negative or false positive results. Therefore, it is important to further optimize the application of these two dyes in surgery. We analyzed case files of 124 PTC patients who underwent routine total or near-total thyroidectomy with bilateral lymph node dissection in the central region at the Affiliated People's Hospital of Ningbo University from January to November 2022. The patients were randomly divided into three groups based on the type of intraoperative dye used. The CNP group (n = 38) received an intra-thyroidal injection of CNP dye. The ICG group (n = 42) used the ICG near-infrared fluorescence endoscopy system to show parathyroid fluorescence. The group that received a combined approach of ICG and CNP (n = 44) leveraged the advantages of both methods that allow for positive development of ICG and negative development of CNP to identify and preserve the parathyroid gland during operation. The parathyroid hormone detection reagent (PTH test method) was employed to verify the highly suspected parathyroid tissue in all three groups. We analyzed intraoperative data pertaining to intraoperative parathyroid identification, misexcision, number of autotransplantation, and postoperative hypoparathyroidism among the three groups. Compared with the ICG group and the CNP group, the combined group demonstrated more prominent advantages in identifying average the number of lower parathyroid glands (1.93 ± 0.26, p = 0.015), reducing the average numberrate of misexcision (0.45 ± 0.5, p = 0.004), and reducing the incidence of postoperative temporary hypothyroidism (3/44, p = 0.015). The combined use of ICG and CNP dual-dye with PTH test method appears to be more effective in both identifying and protecting parathyroid glands during PTC surgery.

Dynamics of PTH levels in the development of post-operative hypoparathyroidism

BACKGROUND

Post-operative hypoparathyroidism is the most frequent complication after total thyroidectomy. The identification of preoperative predictors could be helpful to identify patients at risk. This study aimed to evaluate the potential influence of preoperative PTH levels and their perioperative dynamics as a predictor of transient, protracted, and permanent post-operative hypoparathyroidism.

METHODS

A prospective, observational study that includes 100 patients who underwent total thyroidectomy between September 2018 and September 2020.

RESULTS

Transient hypoparathyroidism was present in 42% (42/100) of patients, 11% (11/100) developed protracted hypoparathyroidism, and 5% (5/100) permanent hypoparathyroidism. Patients who presented protracted hypoparathyroidism had higher preoperative PTH levels. The protracted and permanent hypoparathyroidism rate was higher in groups with greater preoperative PTH [0% group 1 (<40 pg/mL) vs. 5.7% group 2 (40-70 pg/mL) vs. 21.6% group 3 (>70 pg/mL); p = 0.03] and (0 vs. 8.3 vs. 20%; p = 0.442), respectively. The rate of protracted and permanent hypoparathyroidism was higher in patients with PTH at 24 h lower than 6.6 pg/mL and whose percentage of PTH decline was higher than 90%. The rate of transient hypoparathyroidism was higher in patients who showed a PTH decline rate of more than 60%. The percentage of PTH increase one week after surgery in patients with permanent hypoparathyroidism was significantly lower.

CONCLUSION

The prevalence of protracted hypoparathyroidism was higher in groups with higher preoperative PTH levels. PTH levels 24 h after surgery lower than 6.6 pg/mL and a decline of more than 90% predict protracted and permanent hypoparathyroidism. The percentage of PTH increase a week after surgery could predict permanent hypoparathyroidism.

Risk factors for postoperative hypocalcemia following total thyroidectomy: a retrospective study

BACKGROUND

and Objectives: Hypocalcemia is a commonly reported complication after thyroid surgery. Many possible risk factors have been identified. The purpose of this study is to analyze various risk factors possibly associated with development of postoperative hypocalcemia after thyroid surgery by dividing the sample population into postoperative hypocalcemia and normal calcium groups.

DESIGN

Retrospective.

SETTING

Multiple centers in the Makkah region of Saudi Arabia.

PATIENTS AND METHODS

Risk factors for postoperative hypocalcemia that were obtained for analysis include patient factors, perioperative blood parameters factors, disease-related factors, and surgical factors. Postoperative hypocalcemia was defined as a reduction of the total calcium level to <8.0 mg/dL. Hypocalcemic and normocalcemic patients were compared by multivariate logistic regression.

MAIN OUTCOME MEASURES

Distinguish independent risk factors for postoperative hypocalcemia after thyroidectomy.

SAMPLE SIZE

215 patients.

RESULTS

The incidence of hypocalcemia was 52.1% (112 of 215 patients). According to multivariate analysis, statistically significant risk factors for predicting postoperative hypocalcemia included postoperative parathyroid hormone level <10 pg/dL, inadvertent parathyroid gland resection, and neck dissection surgeries.

CONCLUSION

The causes of postoperative hypocalcemia are multi-factorial. Because many of these factors are modifiable, they should be identified postoperatively to distinguish high-risk groups and implement early preventive measures.

LIMITATIONS

Retrospective with a relatively small size. We encourage additional prospective studies with a larger sample size in multiple regions of the country, which might reveal further significant results.

Comparison of bilateral axillo-breast approach robotic thyroidectomy and open thyroidectomy for papillary thyroid carcinoma

For papillary thyroid carcinoma (PTC) surgery requiring total thyroidectomy and central lymph node dissection, it is controversial whether the bilateral axillo-breast approach robotic thyroidectomy (BABA RT) can replace the open thyroidectomy (OT). To evaluate the efficacy of two surgical approaches. Relevant literatures were searched from PubMed, EMBASE and Cochrane Library. Studies comparing two surgical approaches and meeting the inclusion criteria were selected. Compared with OT, BABA RT showed a similar incidence of postoperative complications, including recurrent laryngeal nerve palsy, hypocalcemia, hypoparathyroidism, bleeding, chyle leakage and incision infection, as well as number of retrieved central lymph nodes and postoperative total dose of radioactive iodine. However, BABA RT involved longer operative time (weighted mean difference [WMD] 72.62, 95% confidence interval [CI] 48.15-97.10, P < .00001) and higher postoperative stimulated thyroglobulin level ([WMD] 0.12, 95% [CI] 0.05-0.19, P = .0006). The efficacy of BABA RT is basically similar to OT in this meta-analysis, but the higher postoperative stimulated thyroglobulin level attracts our attention. Longer operative time requires us to shorten. Randomized clinical trials with large samples and longer follow-up data are still essential to further demonstrate the value of the BABA RT.

Effect of Microdissection of Inferior Thyroid Artery on Post-operative Hypocalcemia in Total Thyroidectomy

Hypocalcemia is one of the most common complication after bilateral thyroid surgery. Reported rates range from 5 to 35% and 0.5 to 4.4% for transient and permanent hypocalcemia respectively. Various methods have been devised to reduce the post-operative hypocalcemia and range from modification of surgical techniques to use of loops and avoidance of inadverant neck dissections. We conducted a randomised control trial of 50 patients divided into two groups, to evaluate the effect of microdissection and ligation of distal branches of inferior thyroid artery (group B) on incidence of temporary and permanent hypocalcaemia in patients of total thyroidectomy versus its ligation distally close to the thyroid capsule(group A). Postoperative mean total serum calcium levels were lower in group A as compared to group B (9.13 mg/dl vs. 9.33 mg/dl at 24 h; 8.77 vs. 9.10 at 3rd day and 8.58 vs. 8.96 mg/dl on 10 th day) with p > 0.05. The value of ionized serum calcium as recorded on 3rd day was 4.39 mg/dl for group A and 4.72 mg/dl for group B with p value ≤ 0.001 (Table 2). 19 patients in group A required calcium supplementation for 6 months with incidence of transient hypocalcemia at 76% while 11 patients in group B had calcium supplementation for 6 months with incidence of 40% and difference was significant statistically. Microdissection technique is better for preventing the temporary hypocalcemia and hence decreasing the hospital visits of the patient when compared to the ligation of inferior thyroid artery distally close to the thyroid gland. The incidence of permanent hypocalcemia doesn't varies significantly between both techniques.

The role of preoperative vitamin D and calcium in preventing post-thyroidectomy hypocalcaemia: a systematic review

BACKGROUND

The thyroid gland plays an important endocrine function regulating metabolism, growth and development. A variety of benign and malignant conditions necessitate surgical removal of the thyroid gland, either in its entirety, or partially. Thyroidectomy is the most commonly undertaken endocrine surgery. Hypocalcaemia, occurring at a rate of approximately 25%, is the most common complication following total thyroidectomy. Hypocalcaemia can increase healthcare costs requiring further investigations, treatment and delaying discharge. Severe hypocalcaemia can be potentially life threatening. It has been demonstrated that routine post-operative supplementation with Vitamin D and calcium, can reduce post-operative hypocalcaemia, at present it is unclear whether preoperative supplementation has a similar effect.

METHODS

This systematic review includes randomised controlled trials on human adult subjects, who received preoperative Vitamin D and/or calcium, and which studied the effect on post-operative hypocalcaemia following total or near total thyroidectomy. There were no restrictions in respect of post-operative supplementation regimen. Studies were limited to those published in English.

RESULT

Seven of the eleven trials demonstrated a reduction in either laboratory or clinical hypocalcaemia with preoperative supplementation. This benefit was most likely to be seen when postoperative supplementation was performed on an as needed basis. IV calcium was required to treat resistant or severe hypocalcaemia, in five of the eleven trials, in each of these five trials, rates of IV replacement were lower in the preoperative supplementation group.

CONCLUSION

The use of preoperative Vitamin D, with or without calcium, may provide a modest reduction in the incidence of laboratory and clinic hypocalcaemia following total or near total thyroidectomy. There is a trend toward a reduced requirement for IV calcium with preoperative supplementation. Larger robust randomised trials are needed to provide a definitive answer. Preoperative supplementation can be considered in patients undergoing total or near total thyroidectomy.

Effect of gasless endoscopic thyroidectomy through an axillary approach on the recurrent laryngeal nerve injury in patients with thyroid cancer

OBJECTIVE

To observe the effect of gasless endoscopic thyroidectomy through an axillary approach (GETAN) on the recurrent laryngeal nerve in patients with thyroid cancer.

METHODS

One hundred and ten patients with thyroid cancer admitted to the department of general surgery, the First Affiliated Hospital of Xiamen University were retrospectively selected as the research subjects. They were divided into an observation group (OG, 55 patients, treated with GETAN) and a control group (CG, 55 patients, treated with conventional radical resection for papillary thyroid cancer). Clinical indicators, pain degree, negative emotions, recurrent laryngeal nerve injury, vocal and swallowing function, and the incidence of complications were compared between the two groups.

RESULTS

In terms of clinical indicators, the operation time, intraoperative blood loss, extubation time, and hospitalization time in the OG were shorter than those of the CG (all P<0.05). The scores of Visual Analogue Scale (VAS) at one, two, and three days after surgery in the OG were lower than those in the CG (all P<0.001). As for the negative emotions, the Self-Rating Anxiety Scale score, and Self-Rating Depression Scale score in the OG were lower than those in the CG (both P<0.001). The incidence of postoperative recurrent laryngeal nerve injury in the OG was lower than that of the CG (P<0.001). Another analysis showed that GETAN was a protective factor against recurrent laryngeal nerve injury in patients with thyroid cancer (P<0.05). The Voice Handicap Index and Swallowing impairment score one week and one month after surgery were lower in the OG than in the CG (all P<0.001). The incidence of postoperative complications such as hypocalcemia, wound infection, and numbness of hands and feet in the OG was lower than that in the CG (all P<0.001).

CONCLUSION

The GETAN approach is able to relieve postoperative pain, anxiety, and depression; reduce the laryngeal recurrent nerve injury; promote the recovery of laryngeal recurrent nerve; and decrease the incidence of vocal and swallowing dysfunction It is worthy of clinical promotion.

An Audit of the Procedure of Open Thyroidectomy at A Tertiary Care Centre

We plan to evaluate the various variables associated with the complications of thyroidectomy performed at our department in the last 5 years. Medical records of the patients who underwent thyroidectomy during 2014-2018 were collected. Complications of hypocalcemia and recurrent laryngeal nerve palsy were analysed in terms of the demography, cytopathology and the extent of surgery. Student's t-test, Mann-Whitney U-test, Fisher exact test and chi square test were applied to look for any significant associations. P value < 0.05 was considered significant. 123 patients were analysed (87 females, 38 males). Mean age was 38.3 years (range 11-71 years). Most common cytopathology was papillary carcinoma thyroid (Bethesda VI) - 43/123 (35%). 107 of these 123 patients underwent primary surgery, 10 underwent revision surgery while 6 underwent completion thyroidectomy. Seven patients incurred RLN palsy out of which 3 were temporary. RLN palsy was seen in only malignant cases (p < 0.05). Incidence was higher in T4a stage (p < 0.05). However, it had no association with a simultaneous central or lateral neck dissection. Hypocalcemia was seen in 22 patients (17.8%), out of whom 9 patients developed permanent hypocalcemia. It was seen significantly higher in patients undergoing central neck dissection (p < 0.05) and in malignant thyroid lesions (p < 0.05). Gender, age and the cytopathology had no bearing on RLN palsy and hypoparathyroidism. Malignant thyroid lesions had a significantly higher incidence of RLN palsy and hypoparathyroidism. A thorough anatomical knowledge can reduce the incidence of these complications.

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

Objective

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

Background

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

Methods

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

Conclusions

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

Assessment of diagnostic capacity and decision-making based on the 2015 American Thyroid Association ultrasound classification system

BACKGROUND

This study evaluates the American Thyroid Association (ATA) ultrasound (US) classification system for the initial assessment of thyroid nodules to determine if it indeed facilitates clinical decision-making.

AIM

To perform a systematic review and meta-analysis of the diagnostic value of the ATA US classification system for the initial assessment of thyroid nodules.

METHODS

In accordance with the PRISMA statement for diagnostic test accuracy, we selected articles that evaluated the 2015 ATA US pattern guidelines using a diagnostic gold standard. We analyzed these cases using traditional diagnostic parameters, as well as the threshold approach to clinical decision-making and decision curve analysis.

RESULTS

We reviewed 13 articles with 8445 thyroid nodules, which were classified according to 2015 ATA patterns. Of these, 46.62% were malignant. No cancer was found in any of the ATA benign pattern nodules. The Bayesian analysis post-test probability for cancer in each classification was: (1) Very-low suspicion, 0.85%; (2) Low, 2.6%; (3) Intermediate, 6.7%; and (4) High, 40.9%. The net benefit (NB), expressed as avoided interventions, indicated that the highest capacity to avoid unnecessary fine needle aspiration biopsy (FNAB) in the patterns that we studied was 42, 31, 35, and 43 of every 100 FNABs. The NB calculation for a probability threshold of 11% for each of the ATA suspicion patterns studied is less than that of performing FNAB on all nodules.

CONCLUSION

These three types of analysis have shown that only the ATA high-suspicion diagnostic pattern is clinically useful, in which case, FNAB should be performed. However, the curve decision analysis has demonstrated that using the ATA US risk patterns to decide which patients need FNAB does not provide a greater benefit than performing FNAB on all thyroid nodules. Therefore, it is likely that a better way to approach the assessment of thyroid nodules would be to perform FNAB on all non-cystic nodules, as the present analysis has shown the ATA risk patterns do not provide an adequate clinical decision-making framework.

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.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Carbon Nanoparticles for Thyroidectomy and Central Lymph Node Dissection for Thyroid Cancer

PURPOSE

To evaluate whether the application of carbon nanoparticles (CNs) in total or near-total thyroidectomy combined with central lymph node dissection (CLND) for thyroid cancer (TC) is beneficial to lymph node dissection, parathyroid, and recurrent laryngeal nerve (RLN) protection.

METHODS

Relevant literatures were systematically searched on PubMed, EMBASE, and Cochrane Library Databases until March 31, 2021. All analyses were performed using Revman Manager 5.3 software. The main results were the number of central lymph nodes, the number of central metastatic lymph nodes, accidental parathyroidectomy, postoperative hypoparathyroidism, postoperative hypocalcemia, and postoperative transient RLN paralysis.

RESULTS

This meta-analysis identified 4 randomized controlled trials and 8 non-randomized controlled trials comprising 1870 patients. Compared with the control, the use of CNs was helpful to dissect more central lymph nodes (weighted mean difference [WMD]: 3.55, 95% confidence interval [CI]: 2.12-4.98, P < .00001) and central metastatic lymph nodes (WMD: 1.69, 95% CI:1.31-2.08, P < .00001), lower rate of accidental parathyroidectomy (odds ratio [OR]: .33, 95% CI: .23-.47, P < .00001), lower rate of both postoperative transient hypoparathyroidism (OR: .40, 95% CI: .31-.51, P < .00001), and transient hypocalcemia (OR: .37, 95% CI: .27-.51, P < .00001). However, there were no statistical difference between the groups for postoperative permanent hypoparathyroidism (OR: .29, 95% CI: .06-1.28, P = .10), postoperative permanent hypocalcemia (OR: .94, 95% CI: .10-9.16, P = .96), and postoperative transient RLN paralysis (OR: .66, 95% CI: .40-1.12, P = .12).

CONCLUSIONS

The application of CNs in total or near-total thyroidectomy combined with CLND for TC can better dissect the central lymph nodes and protect parathyroid glands (PGs) and their function.

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 Hypocalcemia: A Single-Center Experience

Introduction

Thyroidectomy is a frequent operation performed worldwide. The most common complication following thyroid surgery is hypocalcemia, caused by transient or persistent hypoparathyroidism. This study aimed to investigate the prevalence of hypocalcemia after thyroidectomy and to identify potential risk factors.

Methods

All thyroidectomies performed at a single tertiary center between 2012 and 2017 were retrospectively analyzed. Post-thyroidectomy hypocalcemia was evaluated in relation to risk factors such as age, sex, procedure type, and type of thyroid disease. Data were extracted from patient medical records. Patients with pre-operative hypocalcemia were excluded.

Results

We enrolled 182 patients who underwent thyroidectomy. Female patients comprised 83% (n = 151) of the total patients. Of all patients, 116 (63.7%) had developed post-operative temporary hypocalcemia and three (1.6%) had persistent hypocalcemia. Remarkably, no cases of mortality were reported. There was no significant relationship between the occurrence of hypocalcemia and age, type of thyroid disease, and sex. Conversely, there was a significant relationship between the development of hypocalcemia and the type of procedure (P < 0.001).

Conclusion

Thyroidectomy is a safe surgery with few complications when performed by a skilled surgeon. These complications result in longer hospital stays and higher costs. The most common post-thyroidectomy complication was hypocalcemia. Furthermore, patients who underwent total thyroidectomy were at the greatest risk of developing post-thyroidectomy hypocalcemia.

Sex-Specific Differences in Outcomes Following Thyroidectomy: A Population-Based Cohort Study

INTRODUCTION

Numbers of thyroidectomies and awareness of postoperative quality measures have both increased. Potential sex-specific variations in clinical outcomes of patients undergoing thyroidectomy are controversial.

OBJECTIVE

The aim of this study was to investigate sex-specific differences in outcomes following thyroidectomy.

METHODS

This is a population-based cohort study of all adult patients undergoing either hemi- or total thyroidectomy in Switzerland from 2011 to 2015. The primary outcome was all-cause 30-day readmission rate. The main secondary outcomes were intensive care unit (ICU) admission, surgical re-intervention, in-hospital mortality, length of hospital stay (LOS), postoperative calcium disorder, vocal cord paresis, and hematoma.

RESULTS

Of 16,776 patients undergoing thyroidectomy, the majority of patients undergoing thyroidectomy were female (79%), with a median age of 52 (IQR 42-64) years. Within 30 days after the surgery, male patients had significantly higher rates of hospital readmission (adjusted risk ratio [RR] 1.38; 95% confidence interval [95% CI] 1.11-1.72, p = 0.008) and higher risks for postoperative ICU admission (RR 1.25; 95% CI, 1.09-1.44, p = 0.003) than female patients. There were no significant differences among sexes in the LOS, rates of surgical re-interventions, or in-hospital mortality. While postoperative calcium disorders due to hypoparathyroidism were less prevalent among male patients (RR 0.63; 95% CI, 0.54-0.72, p < 0.001), a 2-fold higher incidence rate of postoperative hematoma was observed (RR 1.93, 95% CI, 1.51-2.46, p < 0.001).

CONCLUSIONS

Male patients undergoing thyroidectomy have higher 30-day hospital readmission and ICU admission rates. Following surgery, male patients revealed higher rates of neck hematoma, while hypocalcemia was more frequent among female patients.

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.

Adverse events in thyroid surgery: observational study in three surgical units with high volume/year

Background

Thyroid surgery, performed for benign or malignant pathologies, is one of the most frequently performed procedures and its frequency has even been increasing in recent years. Postoperative bleeding, recurrent laryngeal nerve (RLN) palsy, associated to dysphonia, dysphagia, dyspnea, and hypoparathyroidism represent the most fearful and common complications. We conducted a multicenter, observational study of retrospectively collected data in three high-volume referral centers, enrolling all patients undergone to thyroid surgery between January 2016 and December 2017 in Parma University Hospital, Cagliari University Hospital and Ferrara University Hospital.

Materials

Patients were divided into five groups, differentiated thyroid carcinoma, medullary thyroid carcinoma, non-toxic benign pathology, hyperfunctioning benign pathology and NIFTP (Non-invasive Follicular Thyroid neoplasm with Papillary-like nuclear features). A follow up at 7 and 30 days was executed, evaluating the onset of paresthesia, dysphonia and dysphagia. A 6-month follow-up was conducted in cases of early complications.

Results

Totally, 1252 patients were eligible for the study: 907 female and 345 male, with a female to male ratio of 2.6:1 and an average age of 53.428. Total thyroidectomy was performed in 1022 cases, lobectomy in 230. After 6 months we recorded paresthesia in 0.5%, dysphonia in 1.8% and dysphagia in 0.5%.

Conclusion

Our study confirms once again that a share of morbidity escapes the possibilities of prediction and control by the operator, depending on patient anamnestic, pathological or anatomical factors.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Preoperative vitamin D deficiency is associated with increased risk of postoperative hypocalcemia after total thyroidectomy

Prior single-institution studies suggest that preoperative vitamin D deficiency (VDD) is associated with postoperative hypocalcemia and a prolonged length of hospital stay following total thyroidectomy. In this study, we employ a multi-institutional, de-identified electronic health records database to address this issue. We hypothesize that total thyroidectomy patients with preoperative VDD will be at an increased associated risk of postoperative hypocalcemia and hospitalization. Using Cerner Health Facts, we identified 2447 patients who underwent total or subtotal thyroidectomy between 2008 and 2016 and who had a documented 25-hydroxyvitamin D concentration obtained within 12 months of the surgery date using International Classification of Diseases 9/10, Current Procedural Terminology and Healthcare Common Procedure Coding System codes. Data from 984 patients who underwent total thyroidectomy were analyzed. Analysis of variance models estimated the effect of VDD on postoperative numerical variables. Multiple logistic regression estimated the risk of postoperative hypocalcemia and hospital stay, adjusting for any imbalanced demographic variables and operative characteristics. On average, postoperative total calcium concentrations in the VDD group were lower by 0.3 mg/dL compared with that of the non-VDD group (p<0.01). The risk of postoperative hypocalcemia was 2.2 times higher in the VDD group compared with the non-VDD group (p<0.01). Although the length of hospital stay after thyroidectomy was longer in the VDD group compared with the non-VDD group (p=0.03), VDD is not an independent risk factor for prolonged hospitalization following thyroidectomy (p=0.13). VDD is associated with a higher risk of hypocalcemia following total thyroidectomy. Prethyroidectomy operative screening for VDD should be considered.

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.

Tiempo óptimo para medición de paratohormona como predictor de hipocalcemia en pacientes posterior a tiroidectomía total

Introducción. La hipocalcemia posterior a tiroidectomía total es una complicación frecuente en la cirugía de tiroides. La hormona paratiroidea ha demostrado ser un predictor confiable para detectar los pacientes con alto riesgo de hipocalcemia significativa y la consecuente necesidad de administrar suplemento de calcio. El objetivo de este estudio fue determinar el tiempo óptimo de medición de la paratohormona para dicho fin. Métodos. Estudio prospectivo realizado en dos instituciones de nivel III en Popayán, Colombia, entre abril de 2016 y febrero de 2018, en el cual se midieron niveles de paratohormona prequirúrgico, a las 0, 2, 4 y 12 horas del postoperatorio, y se compararon con los valores obtenidos a los 3 meses de seguimiento en pacientes sometidos a tiroidectomía total. Se consideró como grupos de riesgo y con necesidad de suplemento de calcio un valor de paratohormona menor de 10 pg/ml o una disminución mayor del 80 % con respecto al valor prequirúrgico. Resultados. Se incluyeron 34 pacientes intervenidos. Tomando como umbral un valor menor de 10 pg/ml, la medición de paratohormona a las 4 horas fue sensible y específica (60 y 93,1 % respectivamente). Para una disminución mayor del 80 % con respecto al valor prequirúrgico, la sensibilidad fue del 60 % y la especificidad del 96,5 %, presentando un valor predictivo positivo de 75 % y negativo del 93,3 %, con una p < 0,001. Discusión. Una disminución mayor del 80 % del valor de paratohormona prequirúrgico medida a las 4 horas después de la tiroidectomía total permite identificar aquellos pacientes con alto riesgo de hipocalcemia significativa, que requieren administración temprana de suplementos de calcio, comparado con la determinación de la disminución a las 0, 2 y 12 horas postoperatorias.

Feasibility of Autofluorescence for Parathyroid Glands During Thyroid Surgery and the Risk of Hypocalcemia: First Results in Belgium and Review of the Literature

Background. Post-operative hypocalcemia remains the most frequent complication after total thyroidectomy. Recently, autofluorescence imaging was introduced to detect parathyroid glands early during dissection. Aim. We aimed to check the feasibility of autofluorescence regarding the number of parathyroid glands visualised and the risk of post-operative hypocalcemia. Methods. In a prospectively gathered cohort of patients undergoing thyroid surgery, we describe the risk of hypocalcemia in relation to the number of parathyroid glands visualised during surgery (and the risk reported in the scientific literature) and the feasibility to obtain an autofluorescence of the parathyroid glands. Results. From 2010 to 2019, 1083 patients were referred for total thyroidectomy in our tertiary referral centre for endocrine surgery, of which, 40 consecutive cases were operated using autofluorescence. Among the autofluorescence group, 14 (35.0%) had all 4 parathyroid glands visualised, compared to 147 (14.1%) in the other patients, without differences in the number of parathyroid glands reimplanted. No permanent hypocalcemia occurred in the autofluorescence group and 17.5% temporary hypoparathyroidism, compared to 3.1% and 31.9% among the other patients, and 4% (95% confidence interval [CI] 3-5%) and 19% (95% CI 15-24%) in the literature. Conclusion. Autofluorescence imaging provides reliable real-time visualisation at any point during thyroid surgery and helps to identify the parathyroid glands before detection with the naked eye. To date, it cannot be used as a standard technique and does not replace meticulous dissection. To become a useful adjunct in peroperative parathyroid management, large multicentre studies need to establish a potential clinical benefit of this novel technique.

A Cohort Study Assessing the Association Between Body Composition Parameters and Symptomatic Hypocalcemia After Total Thyroidectomy

BACKGROUND

Postoperative hypocalcemia is one of the major concerns following thyroidectomy and the most frequent cause of prolonged hospital stay. The aim of this study was to evaluate the relationship between body composition parameters and symptomatic hypocalcemia following total thyroidectomy. In addition, the effects of disease- and patient-related factors on hypocalcemia were investigated.

METHODS

A total of 144 patients were prospectively included between March 2014 and September 2017. Patients were divided into 2 groups according to the presence or absence of clinical symptoms of hypocalcemia. Subsequently, the relationship between body composition parameters and hypocalcemia was evaluated.

RESULTS

Postoperative hypocalcemia-related symptoms occurred in 28 patients (19.4%). Permanent hypocalcemia was not encountered in any patient. Patients with hypocalcemic symptoms were more likely to have nodules ≥40 mm (39.3% vs. 17.2%, P = .011), retrosternal goiters (25.0% vs. 7.8%, P = .017), central lymph node dissection (LND) (32.1% vs. 11.2%, P = .015), and parathyroid autotransplantation (28.6% vs. 3.4%, P < .001) than those without symptoms. However, no differences were observed in the body composition parameters between symptomatic and asymptomatic patients. On multivariate analysis, lower preoperative intact parathyroid hormone (iPTH) levels (odds ratios (ORs) .96, 95% confidence intervals (CIs) .93-.99), the presence of retrosternal goiters (OR 10.26, 95% CI 2.23-47.14), central LND (OR 16.05, 95% CI 3.90-66.07), and parathyroid autotransplantation (OR 36.22, 95% CI 6.76-194.13) predicted hypocalcemia.

DISCUSSION

This study demonstrates that patients with lower preoperative iPTH levels, retrosternal goiters, central LND, and parathyroid autotransplantation are at an increased risk of developing clinical symptoms of hypocalcemia. Body composition parameters have no effect on the incidence of hypocalcemia after total thyroidectomy.

The Effect of Hypomagnesemia on Refractory Hypocalcemia after Total Thyroidectomy: A Single-Center Prospective Cohort Study

BACKGROUND

Hypomagnesemia is known to impede hypocalcemia correction. This prospective observational study aimed to evaluate the impact of serum magnesium levels on the development of refractory hypocalcemia, which remains a concerning problem after total thyroidectomy (TT).

SUBJECTS AND METHODS

Consecutive subjects (n = 312; mean age = 38.4 [range: 13-83] years; M:F = 62:250) undergoing TT for benign or malignant thyroid diseases were evaluated for serum corrected-calcium (8.4-10.4 mg/dL), magnesium (1.7-2.4 mg/dL), intact parathormone (iPTH), and 25-hydroxycholecalciferol (25OHD) levels preoperatively, at 48-h and 6-month post-TT.

RESULTS

Postoperatively, 98 subjects (31.4%) exhibited transient hypocalcemia, 96 (30.8%) had hypomagnesemia, and 52 (16.7%) had refractory hypocalcemia. Preoperatively, 38 subjects (12.2%) had asymptomatic hypocalcemia and 77 (24.7%) had hypomagnesemia. In multivariate logistic regression analysis, independent risk factors of transient hypocalcemia were hyperthyroidism (odd's ratio [OR]: 5.6), 48-h iPTH (OR: 3.2), 48-h magnesium (OR: 2.7), preoperative 25OHD (OR: 0.96), and preoperative calcium (OR: 0.5; each P < 0.01). In receiver-operating characteristic analysis, percent calcium decline and 48-h magnesium reliably predicted transient hypocalcemia with a threshold of 10.5% and 1.9 mg/dL, respectively. Area under curve, sensitivity, and specificity were 0.822, 82.7%, and 72.9%; and 0.649 (each P < 0.001), 68.4%, and 63.1%, respectively.

CONCLUSION

Serum magnesium below 1.9 mg/dL had 2.7 times higher odds of developing transient hypocalcemia post-TT. Hypomagnesemia and percent calcium decline >10.5% within 48-h post-TT are associated with refractory hypocalcemia, which necessitates correction of both the deficiencies for prompt resolution of symptoms.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Post-Thyroidectomy Complications and Risk Factors in Tabuk, Saudi Arabia: A Retrospective Cohort Study

Background Thyroid surgery is one of the most commonly performed procedures internationally. There were no studies conducted in Tabuk, Saudi Arabia, on post-thyroidectomy complications and their risk factors. Objective The aim of this study was to assess post-thyroidectomy complications and determine the risk factors of such complications. Methods This retrospective study included all cases that underwent thyroidectomy at King Salman Armed Forces Hospital, Tabuk, Saudi Arabia, from January 2012 to December 2017. Patients with preoperative hypoparathyroidism, chronic kidney disease, or history of dysphonia were excluded. Data were collected from medical records. Results The study showed 182 patients who underwent thyroidectomy operation between January 2012 and December 2017. Temporary hypocalcemia was developed in 116 patients (63.7%) while it persisted in three (1.6%). Change of voice was reported in five patients (2.7%) while two (1.1%) lost a high-pitched voice. Seroma, hematoma, and tracheal injury were documented in 1.6%, 1.1%, and 0.5%, respectively. Multivariate analysis showed that total thyroidectomy was the most significant (four times) risk factor for the development of hypocalcemia as compared to other surgical procedures. Conclusion Hypocalcemia was the most frequent post-thyroidectomy complication, whereas voice changes, seroma, hematoma, and tracheal injury are rare complications. Additionally, total thyroidectomy has the highest risk of postoperative hypocalcemia.

Truncal vs Branch Ligation of Inferior Thyroid Arteries in Total Thyroidectomy: Does It Affect Postoperative Hypoparathyroidism?

OBJECTIVE

Postthyroidectomy hypoparathyroidism remains a significant challenge. Truncal ligation of the inferior thyroid arteries (ITAs) may lead to an increased risk of hypoparathyroidism; however, dissection along the thyroid capsule with branch ligation of the thyroid arteries could be a safer option. This study's objective was to compare the effect of truncal versus branch ligation of the ITAs on the rate of postoperative hypoparathyroidism.

STUDY DESIGN

Randomized prospective trial in line with the CONSORT guidelines.

SETTING

The study was conducted at a high-volume tertiary care setting.

METHODS

We randomized 319 patients into 2 groups: truncal ITA ligation (n = 157) and branch ITA ligation (n = 162). The primary outcomes were serum calcium and parathormone levels on the second postoperative day, followed by the levels on months 1, 3, 6, and 12. The need for exogenous replacements was noted. The secondary outcomes, such as operative time, blood loss, and other complications, were also recorded.

RESULTS

Our study revealed a significant difference in the incidence of transient hypocalcemia in patients undergoing truncal ITA ligation and branch ITA ligation (22.9% vs 3.1%, P < .05). The results showed that the levels of serum calcium and parathormone dropped on the second postoperative day and that 36 patients from the truncal ITA ligation group required exogenous calcium and vitamin D replacement. In contrast, only 5 patients from the branch ITA ligation group required the same.

CONCLUSIONS

This is the largest randomized trial of patients undergoing thyroidectomy, and it shows that dissection along the thyroid capsule with branch ligation of the ITAs is more likely to preserve parathyroid function as opposed to truncal ligation of ITAs.

Predicting Postthyroidectomy Hypocalcemia: Improving Predictive Ability of Parathyroid Hormone Level

We performed a retrospective study of our large patient cohort aiming to examine the ability to predict postthyroidectomy hypocalcemia. A retrospective review of patients who underwent total or near-total thyroidectomy at our institution between 2008 and 2018 was performed. Postoperative hypocalcemia was defined as Ca level <8.0 mg/dL (reference range: 8.9–10.1 mg/dL) within 30 days of operation. Logistic regression was used to develop models for prediction of the occurrence of postoperative hypocalcemia. Inclusion criteria were met by 1463 patients. Hypocalcemia was documented in 223 patients (15%). Models based on parathyroid hormone (PTH) levels alone had an associated receiver operator characteristic with an areas under the curve (AUC) of 0.79. There was an inverse relationship between time of measurement and PTH levels within the first two hours after thyroidectomy ( P < 0.01). When measured two to six hours after closure, the predictive ability of PTH compared favorably (AUC = 0.82) with either earlier (within the first two hours after closure, AUC = 0.79) or later measurement (6–24 hours after closure, AUC = 0.77). When measured between two and six hours postoperatively, PTH < 19 pg/mL had a sensitivity of 90 per cent and negative predictive value of 96 per cent for postoperative hypocalcemia. The model that included the PTH level, concurrently measured total blood calcium level, and time of measurement had an improved predictive ability with an AUC of 0.87. PTH level of 19 pg/mL measured two to six hours after thyroidectomy had a sensitivity of 90 per cent and a negative predictive value of 96 per cent in our cohort. The model including postoperative PTH level, calcium level, and time of measurement may further improve the ability to predict postthyroidectomy hypocalcemia.

Identifying early postoperative serum parathyroid hormone levels as predictors of hypocalcaemia after total thyroidectomy: A prospective non-randomized study

OBJECTIVE

There is no clear cut-off value of serum parathyroid hormone (PTH) or calcium in which patients are at risk for hypocalcemia after total thyroidectomy. We evaluated the usefulness of serum calcium and PTH concentration measurements after total thyroidectomy in predicting late-occurring hypocalcemia.

DESIGN

A prospective, single-center, non-randomized longitudinal cohort study of 143 patients undergoing thyroidectomy between August 2019 and December 2019 with serum calcium and PTH levels sampled 1 h after surgery and on the first and fifth postoperative day. Hypocalcemia was defined as serum calcium levels < 2.14 mmol/L regardless of clinical symptoms. Normal PTH range was 1.6-6.9 pmol/L.

MEASUREMENTS

The primary outcome measure was presence of hypocalcemia on the first and fifth postoperative day, analyzed by a logistic regression model. The PTH cut-off value for prediction of hypocalcemia was identified using a ROC curve comparing all three time points using the Youden J index.

RESULTS

Out of 143 patients, 52 (36.4%) had hypocalcemia on the fifth postoperative day. Advanced age, concomitant neck dissection and serum PTH levels < 2.9 pmol/L 1 h after surgery and on the first postoperative surgery day were associated with a high risk of hypocalcemia on the first and fifth postoperative day and need for higher doses of calcium supplements (P < 0.0001, AUC 0.748, 95% CI 0.669-0.817, with 76.92% sensitivity and 71.43% specificity).

CONCLUSION

Serum PTH level measured immediately postoperatively and on the first postoperative day is a reliable predictor of postoperative hypocalcemia with important clinical implications.

The prevalence of hypocalcemia following total thyroidectomy. A retrospective study based at King Abdulaziz University Hospital, Jeddah, Saudi Arabia

Objectives:

To estimate the prevalence of hypocalcemia following total thyroidectomy (TT) at a tertiary center.

Methods:

This retrospective study was conducted between 2014 and 2019 at King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia. The study was based at the Department of General Surgery and was approved by the Research Ethics Committee of KAUH. Medical records of 154 patients who had undergone TT were reviewed. Data such as age, gender, level of postoperative calcium at 24 and 48 hours after surgery, parathyroid hormone (PTH) levels, central neck dissection (CCND), histological diagnosis were entered into Microsoft Excel sheets.

Results:

Hypocalcemia occurred more on the second day after surgery in 67.4% of patients. Among them, 83.9% were female and 16.1% were male. The majority of patients were asymptomatic and benign thyroid disease was the most common. There was a significant association between hypocalcemia and the PTH level (p<0.001).

Conclusion:

There was a high prevalence of hypocalcemia on the second day after surgery. Presence of hypocalcemia association with the PTH level. Meticulous surgical technique and preservation of parathyroid vascularity are important in preventing postoperative hypocalcemia.

Central Compartment Nodal Bulk: A Predictor of Permanent Postoperative Hypocalcaemia

Central compartment clearance (CCC) for Papillary thyroid cancers (PTC) is one of the factors causing postoperative hypocalcaemia. We aimed to examine determinants of this major sequela. 41 patients treated for PTCs between 2014 and 2016 were studied. Surgical details, tumour and nodal characteristics, incidence of transient, temporary and permanent hypocalcaemia were noted. Central clearance was done bilaterally in 24 (58.5%) cases, ipsilaterally in 17 (41.6%). Central nodes were involved in 26 (63.4%) cases, unilaterally in 15 (36.6%), bilaterally in 11 (26.8%). Transient hypocalcaemia developed in 10 (24.4%) cases, temporary hypocalcaemia in 6 (14.6%) cases, and permanent hypocalcaemia in 2 (4.9%) cases. 17 (41%) patients were symptomatic. 9 (21.9%) patients received intravenous calcium. The only factor consistently associated with development of hypocalcaemia of all patterns, was the presence of matted central compartment nodes (p = 0.021). Matted nodes also related to a longer length of stay (p = 0.04) and requirement of intravenous calcium (p = 0.000). Extent of CCC, nodal yield, nodal positivity, perinodal extension, number of parathyroids identified, gender or pT size were not significantly associated. Symptomatic patients did not necessarily become permanently hypocalcaemic (p = 0.8). Patients requiring intravenous calcium were more likely to take oral calcium after discharge (p = 0.002). Postoperative hypocalcaemia is more likely in cases with bulky involved central nodes where extensive clearance is done. In routine CCC, even if done bilaterally, preservation of parathyroid function is possible. Permanent hypocalcaemia after CCC need not be taken as inevitable.

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.

Effect of Preoperative Vitamin D Deficiency on Hypocalcemia in Patients with Acute Hypoparathyroidism after Thyroidectomy

Postoperative hypoparathyroidism is a common complication of total or completion thyroidectomy. The association between preoperative vitamin D deficiency (VDD) and the development of more severe postoperative hypocalcemia is still unclear. Objectives. To evaluate the effect of preoperative VDD on severity of hypocalcemia in patients with hypoparathyroidism following thyroidectomy. Methods. Patients who developed acute hypoparathyroidism after total or completion thyroidectomy, defined as postoperative parathyroid hormone (PTH) level <15 pg/mL and albumin-adjusted calcium level <8.6 mg/dL, were prospectively recruited. Patients were divided into two groups according to their preoperative vitamin D status (VDD group: 25-hydroxyvitamin D (25(OH)D) level <20 ng/mL; non-VDD group: 25(OH) level ≥20 ng/mL). The primary outcome was severity of hypocalcemia in postoperative hypoparathyroidism. Significant hypocalcemia was defined as calcium level ≤7.5 mg/dL. Results. Forty-three patients (21 VDD, 22 non-VDD) were enrolled. Serum total albumin-adjusted calcium level was significantly lower in the VDD group (7.71 ± 0.5 vs. 8.16 ± 0.4 mg/dL, p < 0.01), and the incidence of symptomatic hypocalcemia was significantly higher in the VDD group (43% vs. 9%, p=0.01). The median maximal daily supplementary dose of elemental calcium was significantly higher in the VDD group (2,400 vs. 1,500 mg/day, p=0.02). Length of hospital stay was nonsignificantly longer in the VDD group (p=0.06). Preoperative vitamin D level <19.6 ng/mL could predict significant and symptomatic hypocalcemia in postoperative hypoparathyroidism with sensitivity of 90% and 82% and specificity of 70% and 69%, respectively. Conclusion. VDD is an independent risk factor for both significant and symptomatic hypocalcemia in hypoparathyroidism patients after thyroid surgery.

Risk Factors of Incidental Parathyroidectomy and its Relationship with Hypocalcemia after Thyroidectomy: A Retrospective Study

Background: The aim of this study was to determine the incidence of incidental parathyroidectomy, the relationship between incidental parathyroidectomy and postoperative hypocalcemia, and risk factors for incidental parathyroidectomy in patients undergoing thyroid surgery.

Methods: The study was conducted by analyzing the records of patients who underwent thyroid surgery in a tertiary university hospital between January 2012 and December 2017 retrospectively. The risk factors of postoperative hypocalcemia were determined by comparing postoperative Ca values with age, sex, preoperative Ca value, dominant nodule diameter, type of surgery, and histopathological examination of the thyroidectomy material. According to the final pathology results, the patients were divided into two groups - the ones with and without incidental parathyroidectomy. The risk factors for incidental parathyroidectomy were determined by comparing the two groups in terms of age, sex, dominant nodule diameter, type of surgery, and histopathological results (malign/benign).

Results: When the risk factors of postoperative hypocalcemia were examined, female gender, age <28.5 years old, low level of preoperative mean Ca value, and total thyroidectomy were found to be critical risk factors (p<0.05). When the risk factors of incidental parathyroidectomy were examined, total thyroidectomy and thyroid malignancy were found to be important risk factors (p<0.05).

Conclusion: Female gender, age<28.5 years old, low level of preoperative Ca value, and total thyroidectomy were associated with postoperative hypocalcemia, but no relationship was found between incidental parathyroidectomy and postoperative hypocalcemia.

Comparison of hypocalcemia rates between LigaSure and clamp-and-tie hemostatic technique in total thyroidectomies

BACKGROUND

Postoperative hypocalcemia (PH) is a serious complication after total thyroidectomy. This study aimed to compare PH rates between LigaSure Small Jaw (LSJ) and clamp-and-tie hemostatic technique in patients undergoing total thyroidectomy.

METHODS

Four hundred twenty patients were divided into two groups: group L (210 patients) performed with LSJ and group C (210 patients) with clamp-and-tie technique. Serum ionized calcium (iCa) was measured before and 12, 24, 48, 72 hours after surgery. PH was defined as iCa lower than 4.2 mg/dL in at least two measurements.

RESULTS

There was no significant difference between groups in sex, age, extent of surgery, pathology, and the strategy of intraoperative management of parathyroid glands (PG). The PH rate was significantly lower in group L compared to group C (22.9% vs 32.4%, P = .03).

CONCLUSIONS

Compared to clamp-and-tie technique, LigaSure is superior to decrease PH rate after total thyroidectomy.

Frequency of Hypocalcaemia following Total Thyroidectomy

Background & Objective

Patients who undergo Total thyroidectomy are at higher risk for postoperative hypocalcaemia, which can lead to significant short and long term morbidity. The aim of this study was to determine the frequency of postoperative hypocalcaemia undergoing Total thyroidectomy.

Methods

A total of 854 patients who underwent Total thyroidectomy and completion thyroidectomy between January 2003 to December 2016 at Endocrine Surgical unit, Jinnah Postgraduate Medical Centre, Karachi, were included in this retrospective study. Data were obtained for demographics, preoperative diagnosis, postoperative calcium levels, extent of surgery and final surgical pathology.

Results

A total of 854 patients underwent Total thyroidectomy. Of these 87.58% (n=748) were malignant and 12.41% (n=106) were benign. Among the malignant and benign patients, 47.3% (n=404) underwent Total thyroidectomy and 52.69% (n=450) underwent completion thyroidectomy. Overall incidence of transient hypocalcaemia was 7% (n=60) and that of permanent hypocalcaemia was 0.11% (n= 1).

Conclusion

Hypocalcaemia is one of major concern following total- thyroidectomy. Meticulous surgical techniques, identification and preservation of vascularity of parathyroid glands are essential in preventing postoperative hypocalcaemia following total thyroidectomy.

Determination of risk factors causing hypocalcaemia after thyroid surgery

OBJECTIVE

The most common complication after thyroid surgery is hypocalcaemia and it sometimes leads to problems that are difficult to correct in patients. The present study was aimed to determine the risk factors causing the development of hypocalcaemia after thyroid surgery.

METHODS

818 adult patients were included in the study. The data were recorded by examining the hospital automation system and patient files retrospectively. Patients' demographic characteristics, radiological imaging findings, serum biochemical parameters, extent of the performed surgery, histopathological diagnoses were recorded.

RESULTS

The rate of hypocalcaemia was 28.4% (1.7% permanent). In multivariate analysis: the female gender (p = 0.002), heavier thyroid gland (p = 0.084), substernal location (p = 0.004) and cervical lymph nodes dissection (CLND) (p < 0.001) were found to be significantly. Malignant thyroid pathology (p = 0.006) and total thyroidectomy (p = 0.025) increased the risk of hypocalcaemia significantly in univariate analysis. However, this increase in risk was not found to be statistically significant in regression analysis. Significant statistical result was not found on postoperative hypocalcaemia in terms of advanced age, hyperthyroidism and re-operation. The duration of hospitalization was higher in patients with postoperative hypocalcaemia (m = 2 days) (p < 0.001).

CONCLUSION

In our analyses CLND, female gender, substernal location and heavier thyroid gland was found to be the independent risk factors in the development of postoperative hypocalcaemia. The development of postoperative hypocalcaemia may be predicted and measures may be taken to prevent clinical findings.