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

Artificial neural network to predict post-operative hypocalcemia following total thyroidectomy

The primary objective of this study was to use artificial neural network (ANN) to predict the post operative hypocalcemia and severity of hypocalcemia following total thyroidectomy. The secondary objective was to determine the weightage for the factors predicting the hypocalcemia with the ANN. A single center, retrospective case series included treatment-naive patients undergoing total thyroidectomy for benign or malignant thyroid nodules from January 2020 to December 2022. Artificial neural network (ANN) - Multilayer Perceptron (MLP) used to predict post-operative hypocalcemia in ANN. Multivariate analysis was used construct validity. The data of 196 total thyroidectomy cases was used for training and testing. The mean incorrect prediction during training and testing was 3.18% (± σ = 0.65%) and 3.66% (± σ = 1.88%) for hypocalcemia. The cumulative Root-Mean-Square-Error (RMSE) for MLP model was 0.29 (± σ = 0.02) and 0.32 (± σ = 0.04) for training and testing, respectively. Area under ROC was 0.98 for predicting hypocalcemia 0.942 for predicting the severity of hypocalcemia. Multivariate analysis showed lower levels of post operative parathormone levels to be predictor of hypocalcemia (p < 0.01). The maximum weightage given to iPTH (100%) > Need for sternotomy (28.55%). Our MLP NN model predicted the post-operative hypocalcemia in 96.8% of training samples and 96.3% of testing samples, and severity in 92.8% of testing sample in 10 generations. however, it must be used with caution and always in conjunction with the expertise of the surgical team. Level of Evidence - 3b.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-024-04608-9.

No Change in Complications Following Thyroidectomy Despite Increase in Thyroid Cancer Surgeries: A Meta-Regression Analysis

PURPOSE

The increase in thyroid cancer incidence has inevitably led to an increase in thyroid cancer surgeries. This meta-regression analysis aimed to determine if the rate of post-thyroidectomy complications changes by year.

MATERIALS AND METHODS

PubMed and Embase databases were used to perform a systematic literature search of studies published from January 1, 2005, using the keywords "thyroidectomy" and "complication." A meta-regression was performed for post-thyroidectomy hypocalcemia and bleeding.

RESULTS

This meta-analysis included 25 studies involving 927751 individuals. Through the years of publications in this study, there was no significant difference in the proportion of post-thyroidectomy hypocalcemia and bleeding (p=0.9978, 0.6393).

CONCLUSION

Although the number of thyroid surgeries has recently increased, the incidence of post-thyroidectomy hypocalcemia and bleeding did not significantly increase.

Impact of oral administration of calcitriol to prevent symptomatic hypocalcemia after total thyroidectomy: Systematic review and meta-analysis

BACKGROUND

One of the most common complications of total thyroidectomy is post-operative transient or persistent hypoparathyroidism that can cause symptomatic hypocalcaemia. To prevent this complication, shorten the period of hospitalization and reduce morbidity, routine supplementation of oral vitamin D and calcium has been suggested. This systematic review and meta-analysis aims to critically assess the association between pre-operative calcitriol supplementation and post-operative hypocalcaemia.

METHODS

Randomized controlled trial studies were identified by searching PubMed, Scopus, and Google Scholar databases up to 30 March 2023. Screening of titles, abstracts, and full texts of articles were performed, and data were extracted for a meta-analysis.

RESULTS

This meta-analysis includes data from nine randomized controlled trials with a total of 1259 patients but with significant heterogeneity. The results demonstrate that calcium levels were higher in patients who had pre-operative calcitriol supplementation, with a weighted mean difference (WMD) 0.18 (95% confidence interval (CI) = 0.00, 0.37). Pre-operative calcitriol supplementation did not lead to significant changes in parathyroid hormone (PTH) levels, with WMD -0.49 (95% CI: -1.91, 0.94).

CONCLUSION

Pre-operative calcitriol supplementation leads to higher calcium levels, but the high heterogeneity of the included studies (79% to 98.7%) could affect the results.

Evaluation of Hypocalcemia Following Total Laryngectomy With and Without Thyroidectomy

OBJECTIVE

Hypoparathyroidism and associated hypocalcemia are well-established complications following laryngectomy. This study further characterizes the rates of hypocalcemia in patients undergoing total laryngectomy (TL) with and without thyroidectomy and hemithyroidectomy.

STUDY DESIGN

Retrospective cohort study.

SETTING

TriNetX.

METHODS

We queried TriNetX, a deidentified patient database, to identify patients who underwent TL with and without thyroidectomy and hemithyroidectomy. Rates of hypocalcemia, low parathyroid hormone (PTH), calcium, and calcitriol supplementation were compared between groups with multivariable repeated measures logistic regression.

RESULTS

We identified 870 patients in the TL without thyroidectomy cohort, 158 patients in the hemithyroidectomy cohort, and 123 in the total thyroidectomy cohort. Rates of hypocalcemia differed between patients receiving total thyroidectomy versus TL alone for 0 to 1 month (odds ratio [OR]: 2.88 [1.95-4.26]) 1 to 6 months (OR: 5.08 [2.29-11.3]), and 6 to 12 months (OR: 2.63 [1.003-6.88]) postoperatively, with adjustment for age at laryngectomy, race, ethnicity, and gender. Results were similar among those who received calcium supplementation. The rate of low PTH levels differed in these groups for 0 to 1 month (OR: 5.13 [3.10-8.51]), 1 to 6 months (OR: 3.47 [1.46-8.22]), and 6 to 12 months (OR: 3.63 [1.40-9.38]) following surgery. Rates of postoperative calcium supplementation were increased for patients receiving total thyroidectomy versus TL for 1 to 6 months (OR: 2.44 [1.62-3.68]), and 6 to 12 months following surgery (OR: 1.79 [1.18-2.72]).

CONCLUSION

Patients undergoing TL with total thyroidectomy have a higher risk of postoperative hypocalcemia compared to patients receiving TL alone. Risk of parathyroid injury in these patients may warrant further emphasis on PTH measurement after surgery and a multidisciplinary approach to management.

A prospective cross-sectional study on hypocalcemia after total thyroidectomy in patients with Graves' disease: insights on secondary hyperparathyroidism

PURPOSE

To investigate the parathyroid function and calcium (Ca) levels in the secondary hyperparathyroidism (SHPT) state in patients with Graves' disease.

METHODS

We examined 31 consecutive patients with Graves' disease without chronic kidney disease, who were treated with total thyroidectomy. The patients were divided into a normal parathyroid hormone (PTH) group (NPTH group; n = 19) with a PTH level ≤ 65 pg/mL, and a secondary hyperparathyroidism group (SHPT group; n = 12), with a PTH level > 65 pg/mL. The PTH and Ca-related parameters were examined and the risk factors for postoperative hypocalcemia were analyzed.

RESULTS

The preoperative Ca level was significantly lower (2.24 ± 0.06 vs. 2.31 ± 0.07 mmol/L, p < 0.05) in the SHPT group than in the NPTH group. The reduction in PTH, 1,25-dihydroxyvitamin D (1,25(OH)2D), and Ca levels from the preoperative day to the next morning was significantly greater in the SHPT group than in the NPTH group (p < 0.05). When intraoperative factors were included, the decrease in the PTH level alone was significant. SHPT was a significant factor in determining the extent of PTH reduction.

CONCLUSIONS

Hyperfunctioning parathyroid glands in the SHPT state were more susceptible to postoperative PTH reduction, which, combined with low preoperative Ca levels, increased the risk of postoperative hypocalcemia in patients with Graves' disease.

Early parathyroid hormone (PTH) level as a predictor of post-surgical hypoparathyroidism

INTRODUCTION

Post-operative hypocalcemia and postoperative persistent hypoparathyroidism remain the most common complications after thyroidectomy. Many approaches have been developed to prevent them, but actually, a common protocol is not yet individuated.

MATERIALS AND METHODS

We retrospectively analyzed the results of a prospectively collected database. We dosed PTH preoperatively and 4 h after surgery (PTH_4); calcium was evaluated preoperatively, on the first (I_POD) and on the second postoperative day (II_POD). Hypocalcemia was defined when calcium <8 mg/dl. PTH_4 and I_POD calcium serum levels are identified to predict postoperative hypocalcemia.

RESULTS

Three hundred and forty-eight patients were enrolled, 37 patients resulted as hypocalcemic on I_POD and 41 on the II_POD. PTH_4 is related to I_POD (p < 0.001, r = 0.45) and II_POD (p < 0.001, r = 0.44) calcemia. PTH_4-cut-off predicting I_POD hypocalcemia was 10.50 pg/ml (sensitivity: 78.7%, specificity: 72.7%). A PTH_4 value of 11.5 pg/ml is able to predict hypocalcemia during II_POD (sensitivity: 76.5%, specificity: 69.2%). We set up a combined test to predict II_POD hypocalcemia, using PTH_4 and I_POD calcium (sensitivity: 77.8%, specificity: 89.9%).

CONCLUSION

This research shows the association between PTH_4 and postoperative hypocalcemia. The PTH_4 cut-off to predict I_POD-hypocalcemia was 10.5 pg/ml. We analyzed the calcemia trend during the postoperative period and we realized a combined test using PTH_4 and I_POD-calcemia. This test improves the accuracy of the previous test. Further studies, in particular multicentric, with a larger sample are necessary to validate the combined model.

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.

Intraoperative strategies in identification and functional protection of parathyroid glands for patients with thyroidectomy: a systematic review and network meta-analysis

BACKGROUND

This study aimed to assess the benefits and limitations of four intraoperative visualization of parathyroid gland (IVPG) strategies in the identification and functional protection of parathyroid glands (PGs).

METHODS

We searched PubMed, the Cochrane Central Register of Controlled Trials, CNKI, EMBASE, Web of Science and Google Scholar databases until 30 June 2023. Four IVPG strategies were composed of the naked eyes (NE) and three imaging strategies: autofluorescence (AF), indocyanine green fluorescence (ICGF), and carbon nanoparticles (CN). We performed a pairwise meta-analysis (PMA) for direct comparisons and a Bayesian network meta-analysis (NMA) for indirect comparisons.

RESULTS

A total of 29 eligible studies were included. According to NMA and PMA, AF had significantly lower rates of postoperative hypocalcemia and hypoparathyroidism, PG inadvertent resection, and PG auto-transplantation compared to NE, while had significantly higher rate of PG identification. CN showed significantly lower rates of postoperative hypocalcemia and hypoparathyroidism, and PG inadvertent resection compared to NE in PMA and NMA. ICGF showed a significantly higher rate of PG auto-transplantation compared to NE in PMA and AF in NMA. According to SUCRA values, AF showed the best advantage in reducing the rate of postoperative hypocalcemia (0.85) and PG inadvertent resection (0.89), and increasing the rate of PG identification (0.80). CN had the greatest advantage in reducing the rate of postoperative hypoparathyroidism (0.95). ICGF ranked the highest in the rate of PG auto-transplantation (0.98).

CONCLUSIONS

Three imaging strategies demonstrate significant superiority over NE in the intraoperative PG identification and functional protection. AF is the best strategy in reducing the incidence of postoperative hypocalcemia, increasing the rate of PG identification, and reducing the rate of PG inadvertent resection and auto-transplantation. ICGF has great value in assessing PG viability, leading to the trend towards PG auto-transplantation. CN is the best strategy in reducing the incidence of postoperative hypoparathyroidism.

Clinical Efficacy and Mechanism of Vitamin D2 in Treating Hashimoto's Thyroiditis

Objective

Hashimoto's thyroiditis (HT) is one of the most common autoimmune diseases, with the highest incidence rate among autoimmune thyroid disorders. Vitamin D2 may have therapeutic effects on HT. This study aimed to elucidate the molecular mechanisms underlying vitamin D2 therapy for HT.

Methods

Differentially expressed genes (DEGs) associated with vitamin D2-treated HT were identified, and the DEG-associated gene enrichment pathway was explored using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. The correlation between the hub genes and infiltrating immune cells was investigated, and the interactions among the hub genes and target drug and competing endogenous RNA (ceRNA; long non-coding RNA [lncRNA]-microRNA [miRNA]-messenger RNA [mRNA]) regulatory networks were determined.

Results

GO and KEGG enrichment analyses identified a total of 102 DEGs (6 upregulated and 96 downregulated) in the vitamin D2-treated group samples. The area under the curve values of the identified 10 hub genes was as follows: CCR1(0.920), CXCL1 (0.960), CXCL8 (0.960), EGR1 (0.960), FCGR3B (0.920), FOS (1.000), FPR1 (0.840), MMP9 (0.720), PTGS2 (0.960), and TREM1 (1.000). The immune enrichment scores of the mast cell (P = 0.008), neutrophil (P = 0.016), and plasmacytoid dendritic cell (P = 0.016) were significantly decreased in the vitamin D2-treated group (P < 0.05). The hub gene/drug regulatory network included 8 hub genes, 108 molecular drugs, and 114 interaction relationship pairs. The ceRNA regulatory network included 129 lncRNAs, 145 miRNAs, mRNAs (hub genes), and 324 interaction relationship pairs.

Conclusion

Vitamin D2 may play an immunomodulatory role by regulating the aforementioned immune-related molecules and immune cells, thereby improving its therapeutic effects on HT.

Mostaan L, Mohebbi M, Kabiri M, Yaghoubi MA. Preoperative Vitamin.D Status and Post-Total Thyroidectomy Hypocalcemia

Introduction

Hypocalcemia is a common complication of total thyroidectomy (TT). This study was designed to investigate the effect of preoperative vitamin.D (Vit.D) status on the occurrence of post-total thyroidectomy hypocalcemia.

Materials and Methods

Patients who underwent TT without parathyroidectomy were divided into three groups based on their preoperative Serum Vit.D levels (<20 ng/ml, 20-30 ng/ml, and ≥30 ng/ml were considered deficient, insufficient, and normal Vit.D levels, respectively). Serum levels of calcium and phosphorus were measured before and 24 hours after surgery in all patients. The patients were examined for clinical symptoms and signs of hypocalcemia postoperatively. In cases with positive clinical symptoms and signs of hypocalcemia and/or calcium levels <8 mg/dl, PTH level was measured before starting calcium infusion, while serum calcium and phosphorus levels were also measured 24 hours later.

Results

Among 100 patients enrolled in this study, 81% were females. The mean age was 36.60±8.32 years. Before surgery, the mean Vit.D level was 26.9±16.89 ng/ml, while 47% of cases had normal Vit.D level, 32% had insufficient vitamin levels, and 21% had Vit.D deficiency. Twenty-four hours after surgery, the calcium (P=0.356) and phosphorus (P=0.743) levels were not significantly different between the three Vit.D groups. A comparison of postoperative PTH levels between the three Vit.D groups showed no significant difference (P=0.596).

Conclusions

Based on our findings, preoperative serum Vit.D levels did not affect postoperative serum calcium levels.

Impact of Obesity on Risk of Hypocalcemia After Total Thyroidectomy: Targeted National Surgical Quality Improvement Program Analysis of 16,277 Patients

INTRODUCTION

Hypocalcemia following total thyroidectomy (TT) is common due to postoperative parathyroid dysfunction and vitamin D deficiency. Given the association between obesity and vitamin D deficiency, we sought to correlate body mass index (BMI) with hypocalcemia after TT.

METHODS

Patients undergoing TT between 2016 and 2020 were identified from the American College of Surgeons National Surgical Quality Improvement Program thyroidectomy-targeted database. Univariable and multivariable regressions, stratified by BMI category (normal, overweight, obese), identified factors associated with hypocalcemia prior to discharge, within 30 d, and severe hypocalcemic events (emergent evaluation, intravenous calcium supplementation, or readmission).

RESULTS

Sixteen thousand two hundred seventy seven TT were performed with available BMI data. Three thousand five hundred thirty one (21.7%) patients had normal BMI, 4823 (29.6%) were overweight, and 7772 (47.7%) were obese. Patients with BMI ≥ 25 had decreased risk of hypocalcemia before discharge (9.8% versus 13%, odds ratio [OR] 0.73, P < 0.001), 30 d (8.1% versus 10.4%, OR 0.76, P < 0.001), and severe hypocalcemic events (5.5% versus 6.4%, OR 0.84, P = 0.029) compared to normal BMI patients. On multivariable analysis for normal BMI patients, age < 45 y was a risk factor for hypocalcemia before discharge, 30 d, and severe hypocalcemic events (P < 0.05 for all). Additional risk factors in this group for 30-d hypocalcemia included parathyroid autotransplant and central neck dissection (P < 0.05) and recurrent laryngeal nerve injury for severe hypocalcemic events (P = 0.01).

CONCLUSIONS

Younger patients with BMI < 25 are at an increased risk for hypocalcemia and severe hypocalcemic events after TT. These patients may benefit from preoperative counseling and increased calcium/vitamin D supplementation to reduce prolonged hospitalization and mitigate morbidity.

Does Vitamin D Deficiency Really Increase the Risk of Post-surgical Hypoparathyroidism?

Purpose

Postoperative hypoparathyroidism is the most frequent complication after total thyroidectomy. The identification of preoperative predictors could be helpful to identify patients at risk. The aim of this study is to determine if preoperative vitamin D levels are related to transient, protracted, and permanent hypoparathyroidism.

Method

A prospective, observational study that includes 100 patients who underwent total thyroidectomy.

Results

Transient hypoparathyroidism was present in 42% of patients, 11% developed protracted hypoparathyroidism and 5% permanent hypoparathyroidism. The median preoperative Vitamin D levels were higher in patients who developed transient hypoparathyroidism than in patients without this complication (24 ng/mL [RIQ 13-31] vs. 17 ng/mL [RIQ 10-24]; p = 0.024). Patients with preoperative vitamin D levels below 20 ng/mL had a lower percentage of transient hypoparathyroidism (31.4% vs. 53.1%; p = 0.028). The prevalence of protracted and permanent hypoparathyroidism in both groups was similar. Patients with preoperative vitamin D levels lower than 20 pg/mL had higher median PTH levels 24 h after surgery, (37.7 ± 28.2 pg/ml vs. 23.6 ± 18.6 pg/ml; p = 0.037), and suffered a lower postoperative PTH decline (46.2 ± 35.4% vs. 61 ± 29%; p = 0.026).

Conclusions

Patients with vitamin D deficiency had a lower transient hypoparathyroidism rate, higher median PTH levels 24 h after surgery and a lower postoperative PTH decline. We found no association between preoperative vitamin D and the development of protracted or permanent hypoparathyroidism.

Is transoral endoscopic thyroidectomy safe for total thyroidectomy compared to open thyroidectomy? A propensity-score matched cohort study with papillary thyroid carcinoma

BACKGROUND

Transoral endoscopic thyroidectomy via vestibular approach (TOETVA) has become increasingly popular in the treatment of papillary thyroid cancer (PTC). This study aimed to describe the safety and feasibility of total thyroidectomy between the TOETVA and open thyroidectomy (OT) approaches for the treatment of patients with PTC.

METHODS

We retrospectively reviewed 780 consecutive patients suffering from PTC that had undergone total thyroidectomy using TOETVA (n = 107) and OT (n = 673) between April 2016 and December 2021 at our institute. Afterward, a total of 101 matched patients' surgical outcomes were compared using propensity score matching (PSM) analysis.

RESULTS

Before PSM, the patients in the TOETVA group were younger (p < 0.001), had a lower body mass index (p < 0.001) and a greater female population (p < 0.001). After PSM, the TOETVA group was associated with significantly longer operative time (p < 0.001), greater blood loss (p < 0.001), total drainage amount (p < 0.001), higher C-reaction protein level (p < 0.001), better cosmetic satisfaction (p < 0.001) and quality of life (p < 0.001) and lower scar self-consciousness (p < 0.001). There was no statistical difference between the groups in the rate of parathyroid autotransplantation and bilateral lymph node dissection, the positivity of lymph node metastasis, number of dissected lymph nodes and positive lymph nodes, multifocality, postoperative level of blood calcium and parathyroid hormone (PTH), rate of PTH < 15 ng/mL, visual analog scale score, duration of hospital stay, complications, mean thyroid stimulating hormone (TSH)-stimulated Tg level before radioactive iodine, mean Tg level without TSH stimulation, and the proportion of serum Tg level of <1.

CONCLUSION

TOETVA is a safe and feasible technique for better cosmetic effects and similar surgical outcomes compared to conventional open surgery for the studied patients that required total thyroidectomy.

Risk Factors for Calcium-Phosphate Disorders after Thyroid Surgery

INTRODUCTION

Iatrogenic hypoparathyroidism following thyroidectomy is one of the most common complications significantly reducing patients' quality of life.

OBJECTIVES

This study aimed to analyze the risk factors for calcium-phosphate disorders following thyroidectomy.

PATIENTS AND METHODS

The study group consisted of 211 patients who underwent thyroidectomy for different conditions in 2018-2020. Demographic, clinical and surgical risk factors were analyzed against hypoparathyroidism and hypocalcemia.

RESULTS

Hypoparathyroidism occurred in 15.63% of patients, and hypocalcemia occurred in 45% of those operated on. There was statistical significance between hypoparathyroidism and the extent of thyroid surgery: thyroidectomy vs. lobectomy (p = 0.02, OR = 4.5) and surgeon experience (p = 0.016, OR = 6.9). Low preoperative PTH levels were associated with a higher incidence of hypoparathyroidism (p = 0.055, OR = 0.9). There was a statistically significant correlation between the occurrence of hypocalcemia and preoperative vitamin D deficiency (p = 0.04, OR = 3.5). Low calcium levels before surgery were associated with a higher incidence of hypocalcemia (p = 0.051, OR = 0.5). Meta-analyses of selected risk factors confirmed that the most significant factor in the incidence of hypocalcemia was a decrease in PTH levels (p < 0.001).

CONCLUSIONS

The extent of thyroid surgery and the experience of the surgeon are the most significant risk factors for hypoparathyroidism. Hypocalcemia is much more common than hypoparathyroidism. Among the risk factors for hypocalcemia, in addition to the decrease in parathormone levels due to iatrogenic parathyroid damage, we should mention vitamin D deficiency in the preoperative period.

Severe hypocalcemia as a cause of transient ischemic attack? A debatable case and evidence from literature

Hypocalcemia and transient ischemic attack (TIA) are different medical disorders; however, limited evidence suggests a possible link between the two. The underlying pathomechanisms by which hypocalcemia may cause cerebrovascular damage are difficult to comprehend. The aim of the study was to present an individual experiencing TIA that possibly due to severe hypocalcemia that associated with hypoparathyroidism after total thyroidectomy; and to explore the available evidence of its cause-effect relationship through available literature. A 68-year-old man presented to Dr. Zainoel Abidin Hospital, Banda Aceh, Indonesia with complaints of weakness, especially in the right limbs that had worsened in the last week. The patient experienced unconsciousness for an hour before the admission; disorientation and anterograde amnesia over the time of recovering of consciousness. Other complaints included frequent muscle cramps, numbness in both arms and legs, dizziness, swallowing difficulty, nausea, and vomiting. The patient had a history of total thyroidectomy for a large struma diffuse 18 years ago and was prescribed several medications. However, the patient was overwhelmed by forgetfulness which had become more frequent in recent months resulting in medication nonadherence. The vital sign was stable and Chovsteck's sign was positive. The Montreal Cognitive Assessment (MoCA) revealed impairment in the visuospatial/executive component and delayed memory. Laboratory tests revealed severe hypocalcemia, altered thyroid function, hypomagnesemia, elevated D-dimer and fibrinogen, and vitamin D deficiency. TIA and severe hypocalcemia were proposed as the diagnosis. Prompt initiation of appropriate treatment, including calcium supplementation, anticoagulation, and neuroprotective agents, led to significant clinical improvement. Evidence from available literature suggests that there is a possible link between severe hypocalcemia and TIA that occurred in this patient. However, more studies are warrant to establish this cause-effect relationship.

Frequency and Risk Factors of Permanent Hypoparathyroidism After Total Thyroidectomy: An Experience at a Tertiary Care Hospital in Pakistan

OBJECTIVES

Thyroid surgeries are among the most common operations performed in the world. Hypocalcemia following total thyroidectomy (TT) is a common complication that is sometimes difficult to correct. This study aims to determine the frequency of hypocalcemia and permanent hypoparathyroidism (PtHPT) following TT.

METHODS

A total of 363 patient records were reviewed who underwent TT for any reason. Thirty-eight patients did not have a follow-up in the clinic in the postoperative period and were excluded from the final analysis with the final sample as 325. For patients who developed hypocalcemia during the postoperative hospital stay, their lowest calcium levels were recorded and medical records were reviewed for the period of one year for the requirement of oral calcium and active form of vitamin D (calcitriol or alpha calcidiol) in the outpatient setting. Patients who required calcium and vitamin D supplementation for up to 1 year were labeled as having PtHPT. Risk factors were analyzed among those who developed PtHPT.

RESULTS

From a total of 325 patients postoperative hypocalcemia developed in 163 (50.2%) patients, and 162 (49.8%) patients remained normocalcemic. Permanent hypoparathyroidism was found in 42(12.9%) patients and transient HPT in 121 (37.2%). Age, severe postoperative hypocalcemia (PoHC), and readmission for hypocalcemia were independent risk factors for PtHPT.

CONCLUSIONS

Transient hypoparathyroidism (THPT) is common in our setup. Patients who develop severe hypocalcemia postoperatively and need readmission should be closely followed for the development of PtHPT.

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.

Effectiveness of Direct Transcricothyroid Electromyographic Monitoring in Thyroidectomy Surgery

Thyroid surgeries are associated with complications of vocal cord palsy and hypocalcemia which can be debilitating. The usage of intraoperative nerve monitoring is a useful adjunct to direct nerve visualization in thyroidectomies. We advocate the usage of direct transcricothyroid electromyographic monitoring in identifying recurrent laryngeal nerve. We retrospectively collected data of all patients who underwent thyroidectomies (total thyroidectomy, hemithyroidectomy, isthmusdectomy) using direct transcricothyroid electromyographic monitoring from April 2020 to August 2021. Data was analysed based on patient's demographics, comorbidities, complications post thyroidectomy such as vocal cord palsy, transient and permanent hypocalcemia. 50 thyroidectomies were performed, 10 developed unilateral vocal cord palsy. Out of 22 total thyroidectomies, 7 developed transient hypocalcemia and 4 permanently. 1 patient developed vocal cord hematoma secondary to direct insertion of intraoperative nerve monitor's electrode. Direct transcricothyroid electromyographic monitoring is a feasible and effective method in intraoperative monitoring of recurrent laryngeal nerve during thyroid surgeries.

Preoperative vitamin D level is significantly associated with hypocalcemia after total thyroidectomy

BACKGROUND

To evaluate the association of preoperative vitamin D levels with postoperative hypocalcaemia after total thyroidectomy.

METHODS

The medical records of patients who underwent total thyroidectomy between May 2020 and January 2022 and who had a documented preoperative serum 25-hydroxyvitamin D (25-OHD) concentration were retrospectively reviewed. Vitamin D levels were categorized into four groups: <10 ng/mL (severe vitamin D deficiency), 10-20 ng/mL (vitamin D deficiency), 20-30 ng/mL (vitamin D insufficiency), and > 30 ng/mL (vitamin D sufficiency). Multivariate logistic regression was performed to analyse the association of vitamin D levels with the risk of hypocalcaemia after controlling for potential confounding factors.

RESULTS

A total of 196 patients were included in this study. Of these, 47 (24.0%) had preoperative 25-OHD < 10 ng/mL, 62 (31.6%) had 25-OHD of 10-20 ng/mL, 51 (26.0%) had 25-OHD of 20-30 ng/mL and the remaining 36 (18.4%) had 25-OHD > 30 ng/mL. The incidence of postoperative hypocalcemia was highest in the group of patients with severe vitamin D deficiency (42.6% and 23.4% for postoperative laboratory and symptomatic hypocalcaemia, respectively), followed by the group with vitamin D deficiency (29.0% and 16.1%), the group with vitamin D insufficiency (19.6% and 5.9%) and the group with vitamin D sufficiency (5.6% and 2.8%). Multivariate logistic regression indicated that the odds of postoperative laboratory hypocalcaemia for patients with severe vitamin D deficiency and vitamin D deficiency were 13.20 times (95% CI: 2.69-64.79, P < 0.01) and 6.32 times (95% CI: 1.32-30.28, P = 0.02) greater than for those with vitamin D sufficiency, respectively; while the odds of symptomatic hypocalcaemia for patients with severe vitamin D deficiency was 10.18 times (95% CI: 1.14-90.86, P = 0.04) greater than for those with vitamin D sufficiency.

CONCLUSION

Preoperative vitamin D deficiency (< 20 ng/mL), especially severe vitamin D deficiency (< 10 ng/mL), is an independent predictive factor of postoperative hypocalcaemia after total thyroidectomy.

Vitamin D3 Levels in Predicting Transient Hypocalcemia After Parathyroidectomy

Introduction

Hypocalcemia following parathyroidectomy can often be problematic, requiring long-term follow-up. This complication can be permanent or transient. It most commonly occurs following head and neck surgery where there is accidental removal of the parathyroid gland or damage to the blood supply to the gland during dissection. This study aimed to predict transient hypocalcemia and hypoparathyroidism by evaluating preoperative vitamin D.

Methods

We retrospectively reviewed the medical records of 82 patients that had undergone minimally invasive surgery for primary hyperparathyroidism. Data for patient demographics, histopathology, preoperative and postoperative parathyroid hormone (PTH), calcium levels and vitamin D levels were reviewed.

Results

The female to male ratio was 8.1:1 and the mean age was 56.4 ± 6.2. Preoperative vitamin D was normal in 47.6%, 39% had vitamin D deficiency and 13.4% had vitamin D insufficiency. Postoperatively, 23% has hypocalcemia and 10% had hypoparathyroidism. Postoperative median calcium levels were low in both the vitamin D deficiency and insufficiency groups but failed to show a significant association.

Conclusion

In our study, preoperative vitamin D levels failed to show an association between postoperative calcium and PTH levels.

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.

Hipocalcemia posterior a tiroidectomía total: Análisis de dosis para suplemento rutinario profiláctico

Introducción. La hipocalcemia es la complicación más frecuente de la tiroidectomía. La profilaxis con calcio/ calcitriol es una alternativa costo-efectiva, sencilla y expedita para disminuir esta situación, sin alterar la función paratiroidea residual. Lo que no está claro es si hay superioridad de una dosis frente a otra, por lo que el objetivo de este estudio fue evaluar el comportamiento entre diferentes esquemas de profilaxis para hipocalcemia. Métodos. Estudio de cohorte retrospectivo de adultos operados en un hospital de cuarto nivel, entre febrero de 2017 y diciembre de 2020. Se calculó la tasa de síntomas, la hipocalcemia e hipercalcemia bioquímica en el control postquirúrgico durante las siguientes dos semanas. Se hizo análisis bivariado y multivariado entre dosis de calcio/ calcitriol, otros factores asociados y los desenlaces mencionados. Resultados. Se incluyeron 967 pacientes. El 10 % presentaron síntomas. No hubo diferencias significativas en el calcio sérico del control posquirúrgico entre los grupos con distintas dosis de calcio. La dosis de carbonato de calcio >3600 mg/día y el calcio en las primeras 24 horas de cirugía se asociaron a la presencia de síntomas. La dosis de calcitriol  <1 mcg/día y el bocio aumentaron el riesgo de hipocalcemia bioquímica, mientras que la dosis de 1,5 mcg/día lo disminuyó. Ninguna variable evaluada se asoció a hipercalcemia bioquímica. Conclusiones. Teniendo en cuenta los resultados observados con las dosis de calcio y calcitriol, sugerimos iniciar la profilaxis con un esquema de 3600 mg/día de carbonato de calcio y 1,5 mcg/día de calcitriol. Sin embargo, esta dosis debe modificarse en situaciones como bocio o calcio sérico temprano anormal, que fueron las variables asociadas a mayor riesgo en nuestro estudio.

PTH after Thyroidectomy as a Predictor of Post-Operative Hypocalcemia

Post-thyroidectomy hypocalcemia is a frequent complication with significant morbidity, and has been shown to increase hospital stay and readmission rates. The evaluation of serum parathyroid hormone (PTH) levels after thyroidectomy represents a reliable method to predict post-thyroidectomy hypocalcemia, but it remains infrequently used. This retrospective study investigates serum PTH values 3 h after thyroidectomy as a predictor of hypocalcemia. In this study, we enrolled 141 patients aged between 27 and 71 years eligible for total thyroidectomy who presented with multinodular goiter, suspicious nodule on cytological examination, Graves’ disease, or toxic multinodular goiter. Three hours after total thyroidectomy, 53 patients (37.6%) showed a reduction in serum PTH. Of these patients 75.5% developed hypocalcemia by 24 h after surgery and 100% were hypocalcemic after 48 h (p < 0.001). There was no significant difference attributable to the different thyroid diseases, nor to the age of the patients. PTH at 3 h after total thyroidectomy accurately predicts post-operative hypocalcemia. The early detection of patients at risk of developing post-operative hypocalcemia allows for prompt supplementation of calcium and Vitamin D in order to prevent symptoms and allows for a safe and timely discharge.

Morbidity following thyroid and parathyroid surgery: Results from key performance indicator assessment at a high-volume centre in New Zealand

BACKGROUND

Complications following thyroid/parathyroid surgery include recurrent laryngeal nerve (RLN) injury, hypocalcaemia and return to theatre for haematoma evacuation. Rates of these form the basis of key performance indicators (KPI). An endocrine database, containing results from 1997, was established at the North Shore Hospital in Auckland, New Zealand. We aimed to measure complication rates by procedure (thyroid and parathyroid), explore a temporal change in our unit and compare our results against international literature.

METHODS

A retrospective review of the database between July 1997 and February 2020 was performed. The results for each KPI were analysed in total and over consecutive time periods. A review of the literature was carried out to find international complication rates for comparison. A cumulative sum (CUSUM) analysis was performed to give visual feedback on performance.

RESULTS

There were 1062 thyroidectomies and 336 parathyroidectomies from July 1997 to February 2020. Thyroid surgery results found rates of temporary/permanent RLN injury of 1.9%/0.3%, temporary/permanent hypocalcaemia of 22.3/2.5%, and return to theatre for haematoma evacuation of 1.1%. Parathyroid surgery results were, temporary RLN injury of 0.8% (no permanent injury), temporary/permanent hypocalcaemia of 1.7%/0.4%, and return to theatre for haematoma evacuation of 0.3%. CUSUM analysis found KPI results to be comparable with international literature.

CONCLUSION

Our unit's KPI results are comparable to published results in the literature. The use of this clinical database will help in future monitoring of performance and help drive improvement in the service. Embedding prospective data collection as routine practice allows for continuous improvement for the unit.