Preoperative Vitamin D Deficiency Predicts Postoperative Hypocalcemia After Total Thyroidectomy

The Impact of Thyroid Surgery on Calcium and Magnesium Homeostasis: A Prospective Study

OBJECTIVE

Total thyroidectomy constitutes one of the bread-and-butter procedures of surgeons all over the world. Like with any surgical procedure, complications form a part and parcel of the postoperative course in the hospital. Hypocalcemia represents one such prevalent complication post-total thyroidectomy. This study aimed to evaluate the impact of total thyroidectomy on calcium and magnesium levels and to assess the role of magnesium in postoperative hypocalcemia.

METHODS AND MATERIALS

This study was carried out at a tertiary health center over a two-year period from 2022 to 2024. It involved 100 participants with thyroid conditions (benign/malignant) who required total thyroidectomy. Patients with pre-existing conditions affecting calcium levels (e.g., chronic renal failure, medullary carcinoma thyroid, etc.) were expressly excluded. Preoperative calcium, magnesium, and parathyroid hormone (PTH) levels were recorded. Intraoperative parameters such as time and fluid volume were also measured. Postoperatively, serum calcium and magnesium levels, PTH levels, and complications like hypocalcemia and hypomagnesemia were monitored. The descriptive statistics were computed to delineate the study sample. After completion of data collection, data analysis was achieved using IBM SPSS Statistics for Windows, V. 16.0 (SPSS Inc., Chicago, IL). The chi-squared test of significance was utilized to establish statistical correlations between calcium and magnesium levels post-total thyroidectomy. A p-value of less than 0.05 was considered statistically significant.

RESULTS

The study analyzed 100 total thyroidectomy patients. The mean age of patients in our study was 50.7±8.86 years, with 97 females and three males. The most common pathology indicating total thyroidectomy was diffuse colloid goiter (46%), followed by multinodular goiter (38%). Only a single patient had preoperative biochemical hypocalcemia or hypomagnesemia, but none exhibited symptoms. After total thyroidectomy, 15% (n=15) developed hypocalcemia, and 11% (n=11) developed hypomagnesemia. Postoperative mean PTH levels slightly decreased to 28.8±11.75 pg/dl, indicating similar variability to preoperative levels. Patients who underwent intra-capsular dissection had a mean postoperative ionic calcium level of 4.89±0.54 mg/dl, while those who underwent extra-capsular dissection had a slightly lower mean ionic calcium level of 4.72±0.76 mg/dl.

CONCLUSION

Hypocalcemia is one of the most prevalent complications associated with total thyroidectomy. The role of magnesium in maintaining calcium homeostasis after thyroidectomy should be further explored to improve the management of hypocalcemia. Additionally, the type of capsular dissection performed during the surgery can impact the occurrence of hypocalcemia, and using intra-capsular dissection whenever possible may help reduce the incidence of hypocalcemia.

Clinical protocol using calcium and calcitriol after paediatric total thyroidectomy decreases postoperative hypocalcaemia and inpatient blood tests

INTRODUCTION

Postoperative hypocalcaemia is common after thyroidectomy. This study aimed to evaluate whether a standardised post-thyroidectomy protocol using prophylactic calcium and calcitriol reduces hypocalcaemia incidence after total thyroidectomy in children and adolescents.

METHODS

A cohort children and adolescents ≤18 years of age undergoing total thyroidectomy between January 2016 and October 2022 in one institution were retrospectively identified and divided into pre-protocol and post-protocol groups. The primary outcome measure was hypocalcaemia (total serum calcium of <2.0 mmol/L; ionised serum calcium of 0.9 mmol/L). Secondary outcome measures were the occurrence of hypercalcaemia (serum Calcium >2.7 mmol/L; ionised calcium >1.31 mmol/L), length of hospitalisation and number of postoperative blood tests.

RESULTS

There were 22 patients in each group (mean age 11.8; SD 4.3 years, female 36 %). The rate of hypocalcaemia was significantly higher in the pre-protocol group than the post-protocol group (54 % vs 13.6 %, p = 0.010). Patients in the pre-protocol group had more inpatient blood tests (mean 5.4; SD 3.2) than the post-protocol group (mean 3.3; SD 1.8, p = 0.011), although the total postoperative blood test count was similar between the groups. Six (13.6 %) patients developed hypercalcaemia. The rate of hypercalcaemia was similar between groups (pre-protocol 2, 9.1 %; post-protocol 4, 18.1 %; p = 0.664). Length of hospitalisation was similar between groups.

CONCLUSION

Our standardized protocol decreased hypocalcemia and inpatient blood tests after total thyroidectomy in children. Future research should explore if incorporating preoperative calcium and calcitriol treatment, along with intraoperative PTH levels for risk management, can further reduce hypocalcemia rates in paediatric patients.

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.

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.

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.

Definition and diagnosis of postsurgical hypoparathyroidism after thyroid surgery: meta-analysis

Background

Postsurgical hypoparathyroidism (PH) is the most frequent complication after thyroid surgery. The aim of this systematic review and meta-analysis is to summarize a unifying definition of PH and to elucidate the best possible approach for early detection of PH.

Methods

A systematic review of the literature according to the PICO framework using Embase, PUBMED and the Cochrane library was carried out on 1 December 2021 followed by analysis for risk of bias, data extraction and meta-analysis. All studies addressing the definition of postoperative hypoparathyroidism and/or diagnostic approaches for early detection and diagnosis were included. Case reports, commentaries, non-English articles, book chapters and pilot studies and reviews were excluded.

Results

From 13 704 articles, 188 articles were eligible for inclusion and further analysis. These articles provided heterogeneous definitions of PH. Meta-analysis revealed that postoperative measurements of parathormone (PTH) levels have a higher sensitivity and specificity than intraoperative PTH measurements to predict PH after thyroid surgery. None of the timeframes analysed after surgery within the first postoperative day (POD1) was superior to predict the onset of PH. PTH levels of less than 15 pg/ml and less than 10 pg/ml are both reliable threshold levels to predict the postoperative onset of PH. A relative reduction of mean(s.d.) PTH levels from pre- to postoperative values of 73 (standard deviation 11) per cent may also be predictive for the development of PH. The estimation of calcium levels on POD1 are recommended.

Conclusion

PH is best defined as an undetectable or inappropriately low postoperative PTH level in the context of hypocalcaemia with or without hypocalcaemic symptoms. PTH levels should be measured after surgery within 24 h. Both threshold levels below 10 and 15 pg/ml or relative loss of PTH before/after thyroid surgery are reliable to predict the onset of PH.

Factors associated with postoperative hypocalcemia following thyroidectomy in childhood

BACKGROUND

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

PROCEDURE

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

RESULTS

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

CONCLUSIONS

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

Short-Term Hypocalcemia Prophylaxis With Calcitriol Before Thyroidectomy

BACKGROUND

Total thyroidectomy is the most common surgical treatment of thyroid diseases, and postoperative hypocalcemia is its most common complication. Hypocalcemia prolongs the patient's hospital stay and impairs his or her quality of life. Although a low vitamin D level is a recognized risk factor, the utility of preoperative vitamin D administration to prevent postoperative hypocalcemia is unclear. In this trial, therefore, we studied the effect of giving vitamin D before total thyroidectomy.

METHODS

In a multicenter, randomized, minimally interventional trial (registration number: DRKS 00005615), patients about to undergo total thyroidectomy were randomized either to an intervention group that received 0.5 μg of calcitriol per os twice daily for three days up to the day immediately before surgery, or to a control group that did not (no placebo was given). The primary endpoint was the absence of hypocalcemia (serum calcium <2.1 mmol/L) in the postoperative course.

RESULTS

Of the 287 patients recruited in six hospitals over the period 23 July 2014 to 20 March 2017, 246 were included in the final analysis. The intervention and control groups did not differ significantly with respect to the rate of postoperative hypocalcemia (29.2% and 33.6%, respectively; p = 0.546, power 8.8%). The duration of postoperative hypocalcemia was, however, shorter in the intervention group (3.5 vs. 7 days; p = 0.016, power 68%). The rates of hypocalcemia in the individual trial locations varied widely, ranging from 13.9% to 71.4%.

CONCLUSION

Short-term administration of calcitriol did not affect the rate of occurrence of hypocalcemia after thyroidectomy, but did shorten its duration. The rate of postoperative hypocalcemia varied widely across hospitals, probably because of differences in surgical technique.

[CME: Hypocalcemia and Hypoparathyroidism]

CME: Hypocalcemia and Hypoparathyroidism Abstract. Dyselectrolytemias are common, but not immediately clearly assignable. In addition to hyponatremia, hypercalcemia plays an important role in clinical practice. Clinically no less relevant are hypocalcemias and a frequently underlying primary hypoparathyroidism, which in most cases is iatrogenic - caused by thyroid surgery. The therapeutic goal includes not only adequate calcium control but also the detection and treatment of secondary complications in cases of chronic hypoparathyroidism.

[Review of clinical practice guidelines for hypoparathyroidism]

Hypoparathyroidism is a rare disorder characterized by the absent or inappropriately decreased serum parathyroid hormone in the parathyroid glands, which is accompanied by impaired calcium-phosphorus metabolism.The main etiology of hypoparathyroidism remains damage or removal of the parathyroid glands during neck surgery. In view of the incidence of thyroid cancer, primary hyperparathyroidism and other pathologies of the neck organs, which radical treatment can lead to the parathyroid gland impairment, an increased number of patients with hypoparathyroidism is expected. Autoimmune hypoparathyroidism is the second most common form of the disease, usually occurring as part of type 1 autoimmune polyglandular syndrome. Autoimmune hypoparathyroidism usually occurs in childhood and is characterized by a severe course of the disease, especially in the case of concomitant malabsorption syndrome.Chronic hypoparathyroidism of any etiology requires lifelong multicomponent therapy, as well as careful monitoring and an individual approach to choose the optimal treatment strategy. In the absence of adequate follow-up, the risks of long-term complications significantly increase, particularly in the renal, cardiovascular systems; in the soft tissues and in the brain, it could lead to visual disturbances; pathology of the musculoskeletal system with a decreased bone remodeling and a potential risk of fractures, as well as to the neurocognitive disorders and an impaired health-related quality of life.Timely diagnosis, rational medical therapy and management strategy may reduce the risks of short-term and long-term complications, frequency of hospitalizations and disability of patients, as well as improve the prognosis.This review covers the main issues of Russian guidelines for the management of chronic hypoparathyroidism, approved in 2021, including laboratory and instrumental evaluation, treatment approaches and follow-up. This guidelines also include the recommendations for special groups of patients: with acute hypocalcemia, hypoparathyroidism during pregnancy.

Identification of Patients at High Risk for Postsurgical Hypoparathyroidism

BACKGROUND/AIM

Postsurgical hypoparathyroidism (PostHypo) is a common complication after total thyroidectomy. We studied the risk factors associated with PostHypo.

PATIENTS AND METHODS

The study included 109 women, (mean age: 50.7±10.75 years), who underwent total thyroidectomy for thyroid diseases.

RESULTS

Based on the development of biochemical hypocalcemia on the first postoperative day following total thyroidectomy, (cCa<8.4 mg/dl), 37 women developed PostHypo and 72 did not. Younger age, a lower preoperative corrected calcium and the presence of parathyroid glands in the specimens were related to the development of PostHypo. Of all patients, 51.4% had a vitamin D deficiency. A parathyroid hormone (PTH) value ≤9.4 pg/ml was 84.9% sensitive and 71.4% specific to predict PostHypo on the 1^st postoperative day. A 50% reduction of the PTH value on the 1^st postoperative day from the preoperative level could identify patients who develop PostHypo with 76% sensitivity and 75% specificity.

CONCLUSION

PTH postoperative measurement and its alteration from the preoperative level can be used to identify patients who are at increased risk to develop PostHypo.

Phase II randomized study of preoperative calcitriol to prevent hypocalcemia following thyroidectomy

BACKGROUND

A prospective, stratified, randomized, double-blind, placebo-controlled study was conducted to observe the impact of preoperative calcitriol supplementation on serum calcium levels following total thyroidectomy.

METHODS

Subjects were randomized 1:1 to receive 1 μg calcitriol or placebo for 1 week preceding thyroidectomy. The primary outcome measure was change in serum calcium from baseline to 18 h post-thyroidectomy. Subjects were also assessed for incidence of symptomatic hypocalcemia, length of stay, readmission for hypocalcemia, and intravenous calcium supplementation.

RESULTS

Forty-seven patients underwent thyroidectomy; 23 received preoperative calcitriol supplementation, and 24 received placebo. Repeated measures regression demonstrated no difference in postoperative serum calcium over time (p = 0.22). There were no occurrences of hypocalcemia, intravenous calcium supplementation, or readmission in either group. No difference was observed in length of stay (p = 0.38). One patient in the calcitriol group developed Grade 3 hypercalcemia.

CONCLUSIONS

Preoperative calcitriol supplementation had no impact on postoperative serum calcium levels compared to placebo.

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.

Preoperative Vitamin D Deficiency is a Risk Factor for Postthyroidectomy Hypoparathyroidism: A Systematic Review and Meta-Analysis of Observational Studies

CONTEXT

Whether preoperative vitamin D deficiency (VDD) contributes to postoperative hypoparathyroidism (hypoPT) risk is unknown.

OBJECTIVE

This work aimed to meta-analyze the best available evidence regarding the association between preoperative vitamin D status and hypoPT risk.

METHODS

A comprehensive literature search was conducted in PubMed, CENTRAL, and Scopus databases, up to October 31, 2020. Study selection included patients undergoing thyroidectomy with preoperative vitamin D status and postoperative hypoPT data. Two researchers independently extracted data from eligible studies. Data were expressed as risk ratio (RR) with 95% CI. The I2 index was employed for heterogeneity.

RESULTS

Thirty-nine studies were included in the quantitative analysis (61 915 cases with transient and 5712 with permanent hypoPT). Patients with VDD demonstrated a higher risk for transient hypoPT compared with those with preoperative vitamin D sufficiency (RR 1.92, 95% CI, 1.50-2.45, I2 = 85%). These results remained significant for patients with preoperative 25-hydroxyvitamin D concentrations less than or equal to 20 ng/mL (mild VDD; RR 1.46, 95% CI, 1.10-1.94, I2 = 88%) and less than or equal to 10 ng/mL (severe VDD; RR 1.98, 95% CI 1.42-2.76, I2 = 85%). The risk of permanent hypoPT was increased only in cases with severe VDD (RR 2.45, 95% CI, 1.30-4.63, I2 = 45%). No difference was evident in subgroup analysis according to study design or quality.

CONCLUSION

Patients with preoperative VDD are at increased risk of transient hypoPT following thyroidectomy. The risk for permanent hypoPT is increased only for those with severe VDD.

Post-Operative Permanent Hypoparathyroidism and Preoperative Vitamin D Prophylaxis

Permanent hypoparathyroidism, a feared thyroidectomy complication, leads to significant patient morbidity, medical treatment, and monitoring. This study explores whether preoperative high-dose vitamin D loading decreases the incidence of permanent hypoparathyroidism. In a subgroup analysis, the study examines the predictive utility of day 1 parathyroid hormone (PTH) in permanent hypoparathyroidism. Patients (n = 150) were previously recruited in the VItamin D In Thyroidectomy (VIDIT) trial, a multicentre, randomised, double blind, placebo-controlled trial evaluating the role of 300,000 IU cholecalciferol administered orally a week before total thyroidectomy. Patients were contacted postoperatively beyond six months through a telephonic questionnaire. The primary outcome was permanent hypoparathyroidism, strictly defined as the need for activated vitamin D six months postoperatively. Out of 150 patients, 130 (86.7%) were contactable. Permanent hypoparathyroidism occurred in 11/130 (8.5%) patients, with a lower incidence of 5.3% (3/57) in the cholecalciferol group compared to 11% (8/73) in the placebo group; however, this was non-significant (p = 0.34). In a subgroup analysis, no relationship between day 1 PTH level and the incidence of permanent hypoparathyroidism was found (p ≥ 0.99). There was a lower rate of permanent hypoparathyroidism in the cholecalciferol group, which was not significant. The predictive utility of day 1 postoperative PTH levels may be limited to transient hypoparathyroidism.

Vitamin D Insufficiency Predicts Susceptibility of Parathyroid Hormone Reduction after Total Thyroidectomy in Thyroid Cancer Patients

OBJECTIVE

Given its role in the regulation of calcium and PTH levels, vitamin D was presumed as a potential predictor of postoperative hypoparathyroidism. However, the reports about their association were controversial. This study aims to reveal the relationship between preoperative vitamin D and postoperative parathyroid hormone (PTH).

METHODS

A total of 242 papillary thyroid cancer (PTC) patients who underwent total thyroidectomy (TT) during the period from June 2016 to December 2017 at our hospital were enrolled. Patients were divided into two groups, HypoP and Non-HypoP groups, based on postoperative PTH < 15.0 or ≥15.0 pg/mL, and ΔPTH₅₀+ and ΔPTH₅₀- groups, based on postoperative PTH reduction ratio ≥ 50% or <50%. Clinicopathological features and laboratory data were compared between two sets of groups.

RESULTS

Preoperative PTH level was lower in the HypoP group than in the Non-HypoP group (42.83 vs. 47.52 pg/mL, p=0.018). No significant difference of vitamin D insufficiency was found between the HypoP and Non-HypoP groups (80.8% vs. 74.1%, p=0.226). The rate of vitamin D insufficiency was higher in the ΔPTH₅₀+ group than in the ΔPTH₅₀- group (82.6% vs. 68.4%, p=0.010). By multivariate logistic regression analysis, vitamin D insufficiency was an independent predictor of postoperative PTH reduction ratio ≥ 50% (OR = 2.2, p=0.017).

CONCLUSION

Vitamin D insufficiency is not associated with postoperative PTH in PTC patients undergoing TT. However, vitamin D insufficiency is an independent predictor of postoperative PTH reduction ratio.

Seasonal variations in serum levels of vitamin D and other biochemical markers among KSA patients prior to thyroid surgery

Objectives

Serum levels of vitamin D can vary between seasons, which may affect serum calcium levels in post-thyroidectomy patients. This study aimed to determine seasonal variations in serum levels of vitamin D and other biochemical markers in patients prior to thyroid surgery in a KSA hospital.

Methods

In this study, we analysed the data of 685 post-thyroidectomy patients. The preoperative laboratory values of all patients were collected, and the patients were categorized into groups based on the month when the surgical procedure was performed as follows: cold (November–February) and warm/hot groups (March–October).

Results

Serum vitamin D levels were deficient in 70% of the patients, insufficient in 18%, and optimal in 12%. The mean age of patients in the deficient group was significantly lower than that in the optimal group. There were significantly more patients who had vitamin D deficiency during the cold season than during the warm/hot season (p = 0.024). Serum vitamin D levels did not vary between seasons (p = 0.836); however, the preoperative magnesium and thyroid stimulating hormone (TSH) levels were significantly higher during the warm/hot season than during the cold season (p = 0.039 and p < 0.001, respectively). Preoperative calcium level was not significantly different between the cold and warm/hot months (p = 0.282).

Conclusion

This study suggests a non-significant seasonal fluctuation in serum levels of vitamin D with insignificant variation in serum calcium levels during cold and warm/hot seasons. The findings necessitate a careful review of the patients’ biochemical status prior to surgery. Future prospective longitudinal studies are needed to confirm this variability.

Vitamin D Status as a Predictor of Postoperative Hypocalcemia after Thyroidectomy

OBJECTIVE

To determine whether perioperative vitamin D levels are predictive of postoperative hypocalcemia in patients receiving thyroidectomy.

STUDY DESIGN

Single center retrospective study.

SUBJECTS AND METHODS

This study included all patients receiving total or completion thyroidectomy between January 2007 and March 2017 at a single tertiary care hospital. 25-Hydroxyvitamin D (25[OH]D) levels were measured within 42 days prior to surgery or 1 day postoperatively. Hypocalcemia was defined as an adjusted serum calcium <8.0 mg/dL (based on albumin levels) or symptomatic hypocalcemia. Univariate analysis was performed with a 2-sample t test and chi-square test, while multivariate analysis was performed with logistic regression analysis to determine whether perioperative 25(OH)D level is a predictor of postoperative hypocalcemia.

RESULTS

A total of 517 subjects were included in the study, 15.7% (n = 81) of whom experienced postoperative hypocalcemia with a mean ± SD serum calcium level of 7.6 ± 0.5 mg/dL as compared with 8.9 ± 0.5 mg/dL in the normocalcemic population (P < .01). The mean 25(OH)D level for patients with hypocalcemia was 24.4 ± 12.0 ng/mL as compared with 27.5 ± 12.2 ng/mL in patients with normocalcemia (P = .038). Subjects who were hypocalcemic experienced a significantly longer hospital stay (2.9 ± 2.5 vs 1.4 ± 1.1 days, P < .01). After adjusting for preoperative calcium, age, and performance of a neck dissection, subjects with a 25(OH)D level <30 ng/mL were significantly associated with postoperative hypocalcemia (odds ratio, 1.9; P = .041; 95% CI, 1.0-3.3).

CONCLUSION

Using a single-center retrospective study design, we demonstrated that 25(OH)D level is a significant predictor of postoperative hypocalcemia after thyroidectomy.

Postoperative Hypoparathyroidism: Prognosis, Prevention, and Treatment (Review)

This review summarizes the results of studies concerning the problem of post-surgical hypoparathyroidism, a common complication of thyroid gland surgery, decreasing the quality of life in patients and, in some cases, leading to disability. A search for publications was carried out in electronic databases Web of Science, Scopus, Academic Search Complete (EBSCO), eLIBRARY, using keywords. The search depth was 7-10 years. Prevalence of post-surgical hypoparathyroidism was evaluated, the pathogenetic causes of the disease development, its clinical forms, methods of diagnosis and treatment were studied. It has been found that there is no single algorithm for analyzing the prognostic factors for the development of this pathological condition. It is emphasized that drug therapy of post-surgical hypoparathyroidism has a number of adverse effects. Therefore, the issues of prevention and surgical correction are of particular relevance. However, controversial opinions of contemporary authors about their clinical effectiveness determine the scientific and practical significance of further research on these issues.

Vitamin D Deficiency as a Predictive Factor of Transient Hypocalcemia after Total Thyroidectomy

BACKGROUND

Total thyroidectomy (TT) is recommended in the treatment of malignant and benignant thyroid diseases, and, to date, transient hypocalcemia is the most frequent complication after the procedure. We prospectively evaluated the role of vitamin D deficiency as a predictor of postoperative hypocalcemia.

METHODS

This is a prospective cohort study which was conducted between January 2016 and April 2019. A total of 177 consecutive patients (141 (79.7%) women and 36 (20.3%) men) who underwent TT were included in the current study. Hypocalcemia occurred when serum calcium levels were below 8.0 mg/dL or 1.10 mmol/L. Patients were divided into two groups (Group 1, normocalcemic; Group 2, hypocalcemic) and were assessed taking into consideration preoperative serum 25-hydroxy vitamin D (25-OHD) levels, preoperative serum calcium levels, thyroid hormone levels, sex, body mass index (BMI), and smoking habits. Vitamin D deficiency was defined as 25-OHD levels <25 ng/mL.

RESULTS

The incidence of postoperative asymptomatic and symptomatic hypocalcemia in the two groups was 19.8% and 15.8%, respectively. Preoperative 25-OHD level was significantly different between Group 1 and Group 2 (31.5 ± 15.0 ng/mL vs 18.7 ± 9.8 ng/mL,p=0.017). Logistic regression analysis revealed that preoperative vitamin D deficiency was a significant predictive factor of postoperative hypocalcemia (p=0.012), and, specifically, the risk of hypocalcemia increased 15-fold in patients with a preoperative vitamin D level <25 ng/mL (odds ratio [OR], 14.8).

CONCLUSIONS

Postoperative hypocalcemia is significantly associated with low preoperative levels of serum 25-OHD. Our studies demonstrate that vitamin D deficiency (<25 ng/mL) is an independent predictive factor of postoperative 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.

Surgical Complications After Thyroid Surgery: A 10-Year Experience at Jeddah, Saudi Arabia

To evaluate the incidence and predictive risk factors of complications in patients who underwent thyroid surgery at our hospital with a residency training program. This retrospective cohort study analyzed the complications in all patients who underwent thyroid surgery between January 2008 and December 2017. Demographic data, preoperative diagnosis based on fine needle aspiration cytology, surgical approach, permanent pathology, postoperative complications, and factors associated with complications were recorded. At our hospital, 456 patients underwent thyroidectomy. The most common surgical complications were asymptomatic biochemical hypocalcemia and symptomatic hypocalcemia in 109 (23.9%) and 50 (11%) patients, respectively. Other surgical complications included permanent hypocalcemia, transient vocal cord palsy, permanent vocal cord palsy, hematoma, seroma, chyle fistula, and Horner's syndrome. Mean age > 45 years and more extensive surgery were significantly associated with overall complications (P = 0.003; < 0.001). Mean age > 50 years and vitamin D level < 25 nmol/L (< 10 ng/mL) were significantly associated with hypocalcemia (P = 0.008; < 0.001). Moreover, the extent of surgery and advanced thyroid carcinoma were significantly associated with vocal cord palsy (P < 0.001; 0.05). Hypocalcemia and vocal cord palsy are the most significant complications. Thyroid surgery can be performed safely by senior residents in the residency training program under the direct supervision of an experienced surgeon.

Preoperative vitamin D levels do not relate with the risk of hypocalcemia following total thyroidectomy. A cohort study

BACKGROUND

Hypocalcemia is the most common complication following total thyroidectomy. Few factors may relate with increased risk of postoperative hypocalcemia. Preoperative vitamin D values have been evaluated in few studies, but reports present conflicting data. Aim of our study is to evaluate the association of preoperative vitamin D values and hypocalcemia following total thyroidectomy.

METHODS

A retrospective analysis of patients undergoing total thyroidectomy in our department of endocrine surgery between November 2012 and November 2015 was performed.

RESULTS

Mean age of patients was 56.2 years (±14.0) and sex ratio (F:M) was 4.3:1. Sixty-four patients (17.4%) had preoperative vitamin D insufficiency (x<25 nmol/L), 138 patients (37.5%) vitamin D deficiency (25<x<50 nmol/L) and 166 patients (45.1%) vitamin D sufficiency (x>50 nmol/L). Following total thyroidectomy for both benign and malignant pathology, 66 patients (17.9%) had symptomatic hypocalcemia (x<2.0 mmol/L) requiring medical treatment (group 1), 64 patients (17.4%) biochemical hypocalcemia (2<x<2.1 mmol/L) not requiring treatment (group 2) and 238 patients (64.7%) had normal levels (x>2.1 mmol/L, group 3). Mean postoperative PTH value was 25.4 pg/ml (range 2-61). No statistical correlation between postoperative serum calcium and preoperative vitamin D values (R=-0.001, P=0.9849) was found nor associations were found regarding age, sex, type of thyroid disease or BMI.

CONCLUSIONS

In our cohort of patients, preoperative vitamin D levels were not associated with a higher risk of hypocalcemia following total thyroidectomy. Postoperative PTH appears to be the most sensible item to predict the risk of postoperative symptomatic hypocalcemia.

Preoperative vitamin D level as a post-total thyroidectomy hypocalcemia predictor: a prospective study

Introduction

Hypocalcemia is one of the most common complications after total thyroidectomy. Preoperative serum vitamin D concentration has been postulated as a risk factor for this complication. However, the subject is still controversial and the role of vitamin D in the occurrence of hypocalcemia remains uncertain.

Objective

To evaluate the capability of preoperative vitamin D concentrations in predicting post-total thyroidectomy hypocalcemia.

Methods

Forty-seven total thyroidectomy patients were prospectively evaluated for serum 25(OH) vitamin D, calcium and parathyroid hormone before surgery, Calcium every 6 hours, and parathyroid hormone 8 hours post-operatively. Patients were divided according to postoperative corrected calcium into groups without (corrected calcium ≥8.5 mg/dL) and with hypocalcemia (corrected calcium <8.5 mg/dL), who were then evaluated for preoperative 25(OH) vitamin D values.

Results

A total of 72.3% of cases presented altered 25(OH) vitamin D preoperative serum concentrations and 51% evolved with postoperative hypocalcemia. The with and without hypocalcemia groups did not differ for preoperative 25(OH) vitamin D (p = 0.62). Univariate analysis showed that age (p = 0.03), postoperative PTH concentration (p = 0.02), and anatomopathological diagnosis of malignancy (p = 0.002) were predictors of postoperative hypocalcemia. In multivariate analysis only parathyroid hormone in postoperative (p = 0.02) was associated with post-total thyroidectomy hypocalcemia.

Conclusion

Preoperative serum concentrations of 25(OH) vitamin D were not predictors for post-total thyroidectomy hypocalcemia, whereas postoperative parathyroid hormone influenced the occurrence of this complication.

Preoperative vitamin D deficiency is a risk factor for postoperative hypocalcemia in patients undergoing total thyroidectomy: retrospective cohort study

BACKGROUND

The relationship between preoperative vitamin D deficiency and postoperative hypocalcemia in cases of total thyroidectomy (TT) is a matter of controversy and may vary according to geographical scenarios and populations.

OBJECTIVE

The objective here was to evaluate whether preoperative vitamin D deficiency was associated with postoperative symptomatic hypocalcemia in a population in South America.

DESIGN AND SETTING

Retrospective cohort study on data from all patients undergoing total thyroidectomy, with or without central compartment lymph node dissection, from January 2014 to December 2017, at the A. C. Camargo Cancer Center.

METHODS

Patients with benign thyroid disease (Graves' disease, multinodular goiter or hyperthyroidism) or thyroid cancer who underwent primary total thyroidectomy with or without central compartment lymph node dissection were included. The exclusion criteria were simultaneous parathyroidectomy and conditions that could affect serum calcium levels. The data collected included patient demographics, thyroid pathology, extent of the surgical procedure and complications. Information on preoperative and postoperative calcium, parathyroid hormone (PTH) and vitamin D levels were retrieved from the medical records.

RESULTS

1,347 patients were assessed and postoperative hypocalcemia was diagnosed in 284 patients (21%). The vitamin D levels were considered deficient in 243 patients (18%). Postoperative hypocalcemia was diagnosed in 357 patients (31.5%). Multivariate analysis showed that central compartment dissection and preoperative total calcium and deficient vitamin D levels were significant risk factors for postoperative hypocalcemia.

CONCLUSION

Deficient preoperative vitamin D levels were a significant risk factor for postoperative hypocalcemia. Preoperative oral supplementation should be considered, to minimize this risk.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Assessment of the Early and Late Complication after Thyroidectomy

Background

The complications in thyroid surgery have been reported variable in literature. The aim of this study was to evaluate the early and late (3 months after surgery) complication rates of thyroidectomy in a cohort of patients undergoing thyroid surgery at two hospitals of Isfahan University of Medical Science, Iran.

Materials and Methods

This study included 204 patients who candidates for thyroidectomy presenting at Medical Educational Centers of Al-Zahra and Kashani hospitals in Isfahan between March 2016 and March 2017. Clinical data are collected for all patients by continuous enrollment. The patients examined before and after thyroid surgery and the findings were recorded.

Results

The highest prevalence of thyroidectomy was in women (81.9%). The most frequent thyroid surgery was total thyroidectomy and the most common indication for thyroid surgery was suspicious fine-needle aspiration for thyroid malignancy. Hypocalcemia was the most common complication with a frequency of 54.4%. The odds ratios for early complications were 2.375 and 2.542 for intermediate- and low-volume surgeons, respectively, compared to high-volume surgeons.

Conclusions

According to the results of this study, the high level of surgeon's skill is effective to reduce the likelihood of late and early complications; furthermore, the chance of late complications increases with age.

High-dose preoperative cholecalciferol to prevent post-thyroidectomy hypocalcaemia: A randomized, double-blinded placebo-controlled trial

OBJECTIVE

Post-thyroidectomy hypocalcaemia is a significant cause of morbidity and prolonged hospitalization, usually due to transient parathyroid gland damage, treated with calcium and vitamin D supplementation. We present a randomized, double-blinded placebo-controlled trial of preoperative loading with high-dose cholecalciferol (300 000 IU) to reduce post-thyroidectomy hypocalcaemia.

PATIENTS AND MEASUREMENTS

Patients (n = 160) presenting for thyroidectomy at tertiary hospitals were randomized 1:1 to cholecalciferol (300 000 IU) or placebo 7 days prior to thyroidectomy. Ten patients withdrew prior to surgery. The primary outcome was post-operative hypocalcaemia (corrected calcium <2.1 mmol/L in first 180 days).

RESULTS

The study included 150 patients undergoing thyroidectomy for Graves' disease (31%), malignancy (20%) and goitre (49%). Mean pre-enrolment vitamin D was 72 ± 26 nmol/L. Postoperative hypocalcaemia occurred in 21/72 (29%) assigned to cholecalciferol and 30/78 (38%) participants assigned to placebo (P = 0.23). There were no differences in secondary end-points between groups. In pre-specified stratification, baseline vitamin D status did not predict hypocalcaemia, although most individuals were vitamin D replete at baseline. Post-hoc stratification by day 1 parathyroid hormone (PTH) (<10 pg/mL, low vs ≥10 pg/mL, normal) was explored due to highly divergent rates of hypocalcaemia in these groups. Using a Cox regression model, the hazard ratio for hypocalcaemia in the cholecalciferol group was 0.56 (95%CI 0.32-0.98, P = 0.04) after stratification for Day 1 PTH. Further clinical benefits were observed in these subgroups.

CONCLUSIONS

Pre-thyroidectomy treatment with high-dose cholecalciferol did not reduce the overall rate of hypocalcaemia following thyroidectomy. In subgroups stratified by day 1 PTH status, improved clinical outcomes were noted.

Can preoperative vitamin D deficiency predict postoperative hypoparathyroidism following thyroid surgery?

IMPORTANCE

Postoperative hypoparathyroidism remains a relevant problem after thyroid surgery. Although the roles of vitamin D deficiency and other risk factors have been discussed in previous studies, variable results have been reported.

OBJECTIVE

Predicting the risk of postoperative hypocalcemia could be helpful for individual prognoses and medical treatment.

PATIENTS AND METHODS

Documentation and analysis of bilateral thyroid operations performed between July 2011 and May 2014 were studied. Results involving age, gender, diagnosis, surgical techniques, pre- and postoperative calcium and parathyroid hormone (PTH) levels, and especially, the role of preoperative vitamin D levels were assessed in uni- and multivariate analyses.

RESULTS

Bilateral thyroid surgery was performed in 361 patients with multinodular goiters (n = 224), Graves' disease (n = 40), or thyroid carcinoma (n = 97). In total, 124 patients (34%) with postoperative hypoparathyroidism, defined as having a PTH level ≤ 10 pg/mL, were treated with calcium and vitamin D regardless of their symptoms. The rate of permanent hypoparathyroidism was 3.6% and correlated with the extent of surgery; the highest risks were shown for total thyroidectomy and central lymph node dissection. In univariate analysis, the extent of surgery, parathyroid autotransplantation, and histopathology were the strongest predictors of hypoparathyroidism. Even severe vitamin D deficiency (< 10 ng/mL) showed a trend only towards a higher transient hypoparathyroidism risk (p = 0.0514) but failed to predict permanent hypoparathyroidism.

CONCLUSION

Postoperative PTH levels accurately identified patients at risk for hypoparathyroidism. Decreased preoperative vitamin D levels could not predict hypocalcemia, and high vitamin D levels could not prevent permanent hypoparathyroidism.

Risk of major complications following thyroidectomy and parathyroidectomy: Utility of the NSQIP surgical risk calculator

BACKGROUND

The primary objective of this study was to determine rates of reoperation, ED visits, and hospital readmission after thyroid and parathyroid surgery at a tertiary hospital. A secondary objective was to determine if scores from the American College of Surgeons Surgical Risk Calculator (ACS SRC) predicted these events.

METHODS

We retrospectively reviewed the records of patients undergoing parathyroid and thyroid surgery between 2011 and 2014. Patients who underwent an unplanned reoperation, returned to the ED, or were readmitted to hospital were evaluated using the ACS SRC.

RESULTS

436 patients underwent thyroid and parathyroid operations. Rates of re-operations, ED visits and hospital readmissions after thyroid and parathyroid surgery were: 3.4%, 0.6% and 3.0% and 2.2%, 0% and 1.4%, respectively. 71% of patients who experienced post-operative complications scored below average on the ACS SRC, 17% scored above average and 12% scored average risk.

CONCLUSIONS

The SRC did not predict re-operation, ED visits, or hospital readmission after thyroid or parathyroid operations.

Hypoparathyroidism: disease update and new methods of treatment

Гипопаратиреоз характеризуется гипокальциемией при нормальном или низком уровне паратиреоидного гормона (ПТГ). ПТГ регулирует уровень кальция в крови, влияя на реабсорбцию кальция и фосфора в почках, а также витамин D-зависимое всасывание кальция из желудочно-кишечного тракта. Наиболее распространенной причиной гипопаратиреоза является повреждение околощитовидных желез в ходе хирургического вмешательства в области шеи, в основном по поводу заболеваний щитовидной железы. Стандартные методы лечения включают в себя назначение препаратов кальция и витамина D для поддержания уровня кальция на нижней границе референсного интервала с целью предупреждения гиперкальциурии. Однако в ряде случаев компенсация гипокальциемии требует использования высоких доз препаратов кальция и витамина D, что сопровождается выраженным колебанием уровня кальция крови, внескелетной кальцификацией и ухудшением функции почек. В настоящее время наиболее перспективным методом лечения гипопаратиреоза является заместительная терапия рекомбинантным человеческим ПТГ(1-84), который представляет собой полноразмерный ПТГ. ПТГ(1-84) способствует поддержанию стойкой нормокальциемии, улучшая качество жизни пациентов. Однако влияние ПТГ(1-84) на функцию почек, костный обмен и профилактику других осложнений гипопаратиреоза требует дальнейшего изучения.

Impact of pre-operative serum 25-hydroxyvitamin D on post-operative serum calcium in patients undergoing total thyroidectomy for benign goitre: retrospective study of 246 patients

OBJECTIVE

To determine whether pre-operative serum 25-hydroxyvitamin D has an impact on post-operative parathyroid hormone and serum calcium levels in patients undergoing total thyroidectomy for benign goitre.

METHODS

This single-centre, retrospective study comprised 246 unselected surgical patients who had undergone total thyroidectomy for bilateral, benign, multinodular goitre. The correlation between pre-operative serum 25-hydroxyvitamin D and post-operative serum parathyroid hormone and serum calcium was studied to determine whether low pre-operative serum 25-hydroxyvitamin D was predictive of post-operative hypocalcaemia.

RESULTS

Seventy-nine patients (32 per cent) had post-operative hypocalcaemia. Eighteen patients (7.32 per cent) experienced unintentional parathyroidectomy (1 parathyroid gland in 15 patients, 2 parathyroid glands in 3 patients). In univariate analysis, pre-operative serum 25-hydroxyvitamin D was not correlated with post-operative serum calcium (p = 0.69) or post-operative serum parathyroid hormone (p = 0.5804). Furthermore, in multivariate analysis, which took into account unintentional parathyroidectomy, no correlation was found (p = 0.33). Bilateral unintentional parathyroidectomy was statistically associated with post-operative hypocalcaemia (p = 0.032).

CONCLUSION

Pre-operative serum 25-hydroxyvitamin D did not appear to have any impact on post-operative serum calcium in patients undergoing total thyroidectomy for benign goitre.

Association of Preoperative Calcium and Calcitriol Therapy With Postoperative Hypocalcemia After Total Thyroidectomy

Importance

Hypocalcemia is the most common complication after total thyroidectomy and can result in prolonged hospital admissions and increased hospital charges.

Objective

To determine the effectiveness of preoperative calcium and calcitriol supplementation in reducing hypocalcemia following total thyroidectomy.

Design, Setting, and Participants

A retrospective cohort study was conducted at a tertiary care center in 65 patients undergoing total thyroidectomy by a single surgeon. Patients were divided into 2 groups: those receiving preoperative as well as postoperative supplementation with calcium carbonate, 1000 to 1500 mg, 3 times daily and calcitriol, 0.25 to 0.5 µg, twice daily, and those receiving only postoperative supplementation with those agents at the same dosages. Data on patients who underwent surgery between January 1, 2008, and December 31, 2011, were acquired, and data analyses were conducted from March through June 2012, and from October through December 2016.

Interventions

Calcium and calcitriol therapy.

Main Outcomes and Measures

Postoperative serum calcium levels and development of postoperative hypocalcemia.

Results

Of the 65 patients who underwent total thyroidectomy 27 (42%) were men; mean (SD) age was 49.7 (16.7) years. Thirty-three patients received preoperative calcium and calcitriol supplementation, and 32 patients received only postoperative therapy. In the preoperative supplementation group, 15 of 33 (45%) patients underwent complete central compartment neck dissection and 11 of 33 (33%) had lateral neck dissection, compared with 16 of 32 (50%) and 12 of 32 (38%), respectively, patients without preoperative supplementation. The mean measured serum calcium level in those without preoperative supplementation vs those with supplementation are as follows: preoperative, 9.6 vs 9.4 mg/dL (absolute difference, 0.16; 95% CI, -0.12 to 0.49 mg/dL); 12 hours postoperative, 8.3 vs 8.6 mg/dL (absolute difference, -0.30; 95% CI,  -0.63 to 0.02 mg/dL); and 24 hours postoperative, 8.4 vs 8.5 mg/dL (absolute difference, -0.13; 95% CI, -0.43 to 0.16 mg/dL). In patients not receiving preoperative supplementation, 5 of 32 (16%) individuals became symptomatically hypocalcemic vs 2 of 33 (6%) in the preoperative supplementation group; an absolute difference of 10% (95% CI, -6.6% to 26.3%). Compared with the group not receiving preoperative supplementation, the mean [SD] length of stay was significantly shorter in the preoperative supplementation group (3.8 [1.8] vs 2.9 [1.4] days; absolute difference, -0.9; 95% CI, -1.70 to -0.105 days). Preoperative supplementation resulted in an estimated $2819 savings in charges per patient undergoing total thyroidectomy.

Conclusions and Relevance

Preoperative calcium and calcitriol supplementation, in addition to routine postoperative supplementation, was associated with a reduced incidence of symptomatic hypocalcemia, length of hospital stay, and overall charges following total thyroidectomy.

Preoperative vitamin D deficiency and postoperative hypocalcemia in thyroid cancer patients undergoing total thyroidectomy plus central compartment neck dissection

Background

There appears to be a lack of consensus whether preoperative vitamin D deficiency (VDD) increases the risk of postoperative hypocalcemia and decreases the accuracy of postoperative parathyroid hormone (PTH) in predicting hypocalcemia in thyroid cancer patients undergoing total thyroidectomy (TT) plus central compartment neck dissection (CCND). This study aims to address these issues.

Method

All consecutive thyroid cancer patients who underwent TT plus CCND were retrospectively reviewed through a prospectively collected database between October 2015 and April 2016 in a tertiary referral hospital. The multivariate analysis was performed to identify the significant predictors for hypocalcemia. Receiver operator characteristic curve (ROC) was created and the area under the ROC was used to evaluate the predictive accuracy of postoperative PTH and compared between patients with or without VDD.

Results

A total of 186 patients were included. The incidence of VDD was 73.7% (137 patients). The incidence of biochemical and symptomatic hypocalcemia was similar in patients with or without VDD (P = 0.304 and 0.657, respectively). Multivariate analysis showed that only postoperative PTH was an independent predictor of symptomatic hypocalcemia (OR = 8.05, 95%CI = 3.99-16.22; P = 0.000). The area under the ROC was similar between patients with preoperative vitamin D level < 20 and ≥20 ng/mL (0.809 versus 0.845, P = 0.592).

Conclusion

VDD was not a significant risk factor for hypocalcemia following TT+CCND, and did not affect the accuracy of postoperative PTH as a predictor of postoperative hypocalcemia. Thus, routine preoperative screening for vitamin D seems to be unnecessary.

Analysis of factors affecting the development of hypocalcaemia after multinodular goitre surgery

INTRODUCTION

Thyroidectomy is a common surgery performed especially in treatment of multinodular goitre. The most common post-thyroidectomy complication is a postoperative hypocalcaemia, and the percentage of postoperative hypoparathyroidism could reach even 50%. Tested group and methods: A forward-looking, randomized testing was done on a group of 113 women being subject to multinodular goitre surgery. In this article, we wish to present an analysis of the results obtained in the control group, focusing on the predicative factors which determine the development of postoperative hypocalcaemia. Obtained results: The rate of postoperative biochemical hypocalcaemia development was significantly higher in the group of patients, where the preoperative calcium concentration was lower than 2,4 mmol/l. In that group, the development of biochemical hypocalcaemia was observed in 93,7% of cases (30 out of 32 patients), in comparison with 65,3% (17 out of 26) in the group of higher preoperative concentration of calcium. The highest risk of occurrence of postoperative hypocalcaemia was borne by the total thyroidectomy, while the lowest one by the subtotal thyroid lobectomy of one lobe only.

CONCLUSIONS

A higher preoperative concentration of calcium in blood serum is related to the lower rate of occurrence of postoperative biochemical hypocalcaemia. However, no such correlation was revealed in the case of postoperative symptomatic hypocalcaemia. Lack of correlation was determined between the preoperative concentration of TSH and FT4 in blood serum and the rate of occurrence of postoperative hypocalcaemia, both symptomatic and asymptomatic. The performed statistics did not reveal a relation between the postoperative hypocalcaemia and the duration of the surgery, but a significant correlation was stated with the scope of the performed surgery. Revealing a relation between the rate of occurrence of postoperative hypocalcaemia and the experience of the surgeon performing the surgery was not successful.

The Association of Discolored Parathyroid Glands and Hypoparathyroidism Following Total Thyroidectomy

BACKGROUND

It remains uncertain whether a parathyroid gland (PG) that appears darkened or severely bruised but still has an attached vascular pedicle should be left in situ or taken out and auto-transplanted following total thyroidectomy. Our study aimed to examine the impact of discolored PGs (DPGs) on short- and long-term hypoparathyroidism.

METHODS

One hundred and three patients who underwent total thyroidectomy with 4 clearly identified PGs were analyzed. Location (superior/inferior) and color of each PG were recorded. Patients without DPG were grouped into I while those with 1-2 DPGs and ≥3 DPGs were grouped into II and III, respectively. Transient hypoparathyroidism meant adjusted Ca <2.00 mol/L 24 h after surgery and/or need for supplements. Protracted hypoparathyroidism meant a subnormal PTH at 4-6 weeks and/or supplements >6 weeks. Permanent hypoparathyroidism meant supplements ≥1 year.

RESULTS

Relative to I, group III had greater adjusted Ca drop at postoperative 1-h (p = 0.012), 24-h (p < 0.001) and lower day-1 PTH (p = 0.015). Having ≥3 DPGs (OR 14.00, 95 % CI 1.575-124.474, p = 0.018) was an independent factor of transient hypoparathyroidism. However, permanent hypoparathyroidism rate was higher than in group I than II (p = 0.019). Eight patients (25.8 %) in group I had undetectable day-1 PTH, while none in group III had undetectable day-1 PTH. Graves' disease/toxic goiter (OR 15.166, 95 % CI 2.594-88.661, p = 0.003) and excised gland weight (OR 1.028, 95 % CI 1.010-1.046, p = 0.003) were independent factors of ≥3 DPGs.

CONCLUSIONS

PG discoloration is associated with transient hypoparathyroidism while normal colored PG with seemingly adequate blood supply does not always imply functionally normal gland. These findings highlights the need for a real-time intraoperative method to assess PG viability.

DOES PRE-OPERATIVE VITAMIN D DEFICIENCY PREDICT POSTOPERATIVE HYPOCALCEMIA AFTER THYROIDECTOMY?

OBJECTIVE

Postoperative hypocalcemia is frequent after total thyroidectomy. The role of pre-operative vitamin D levels in the pathogenesis of this condition has not been studied under the most current guidelines for evaluation of the role of vitamin D in calcium homeostasis. We hypothesized that patients who are vitamin D deficient (VDD) pre-operatively are more likely to suffer from postoperative hypocalcemia, thereby requiring prolonged hospitalization.

METHODS

A retrospective chart review of patients undergoing total thyroidectomy at the University of New Mexico Hospital between 2005 and 2014 was performed. Patients who underwent intentional parathyroidectomy were excluded. The study included 30 patients who had a 25-hydroxyvitamin D levels obtained within 12 months before surgery.

RESULTS

Twelve patients who were VDD (25-hydroxyvitamin D ≤20 ng/mL) were compared to 18 patients who did not have VDD (non-VDD; 25-hydroxyvitamin D >20 ng/mL). The mean nadir postoperative ionized calcium concentration was lower in the VDD group (0.99 ± 0.10 vs. 1.06 ± 0.06 mmol/L, P = .04) (reference range = 1.15-1.27 mmol/L), as was the postoperative concentration of phosphorus (3.48 ± 0.60 vs. 4.17 ± 0.84 mg/dL, P = .03). VDD patients had a longer length of stay (4.3 ± 4.4 vs. 1.7 ± 1.5 days, P = .03). Three patients in the VDD group required intravenous calcium for treatment of symptomatic hypocalcemia, but none of the non-VDD patients required this intervention (P = .054).

CONCLUSION

Pre-operative vitamin D deficiency is associated with an increased risk of postoperative hypocalcemia and a prolonged length of stay in patients undergoing total thyroidectomy. Vitamin D replacement before thyroidectomy may improve postsurgical outcomes in VDD patients.

ABBREVIATIONS

BMI = body mass index non-VDD = non-vitamin D deficient PTH = parathyroid hormone VDD = vitamin D deficient.

Predictors and risk factors of hypoparathyroidism after total thyroidectomy

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Impact of preoperative Vitamin D3 administration on postoperative hypocalcaemia in patients undergoing total thyroidectomy (HypoCalViD): study protocol for a randomized controlled trial

Background

Total thyroidectomy is increasingly used as a surgical approach for many thyroid conditions. Subsequently, postoperative hypocalcaemia is observed with increasing frequency, often resulting in prolonged hospital stay, increased use of resources, reduced quality of life and delayed return to work. The administration of vitamin D is essential in the therapy of postoperative hypocalcaemia; calcitriol is most commonly used. What has not been examined so far is whether and how routine preoperative vitamin D prophylaxis using calcitriol can help to prevent postoperative hypocalcaemia. This study evaluates routine preoperative calcitriol prophylaxis for all patients who are to undergo a total thyroidectomy, compared with the current standard of post-treatment, i.e., selective vitamin D treatment for patients with postoperative hypocalcaemia.

Methods/design

This clinical observational (minimal interventional clinical trial) trial is a multicentre, prospective, randomized superiority trial with an adaptive design. Datasets will be pseudonymized for analysis. Patients will be randomly allocated (1:1) to the intervention and the control groups. The only intervention is 0.5 μg calcitriol orally twice a day for 3 days prior to surgery. For the primary endpoint measure (number of patients with hypocalcaemia), hypocalcaemia is defined as serum calcium of less than 2.1 mmol/l on any day during the postoperative course; this measure will be analyzed using a Chi-square test comparing the two groups. Secondary endpoint measures, such as number of days to discharge, quality of life, and economic parameters will also be analyzed.

Discussion

By virtue of the direct comparison of clinically and economically relevant endpoints, the efficacy as well as efficiency of preoperative calcitriol prophylaxis of hypocalcaemia will be clarified. These results should be available 24 months after the first patient has been enrolled. The results will be used to inform a revised practice parameter guideline of whether or not to recommend preoperative calcitriol for all patients in whom total thyroidectomy is planned.

Trial registration

Deutsches Register Klinischer Studien, DRKS00005615 (Feb.12.2016).

Single measurement of intact parathyroid hormone after thyroidectomy can predict transient and permanent hypoparathyroidism: a prospective study

OBJECTIVE

Immediate postoperative hypocalcemia is the most common complication of bilateral thyroidectomy. Although hypocalcemia is usually transient, it can be fatal. This study aimed to find a predictor of immediate postoperative hypocalcemia by using intact parathyroid hormone (PTH) level at 4 hours after thyroidectomy (iPTH4hr) compared with the decline in the percentage of intact PTH (%iPTH). We also followed the subjects for evaluation of permanent hypoparathyroidism.

METHODS

This was a prospective study of 65 patients (86.2% female, mean age: 43±15 years) who planned to undergo total or subtotal thyroidectomy. Preoperative and iPTH4hr were measured.

RESULTS

Thirty-nine patients (60%) were diagnosed with papillary thyroid carcinoma, while the rest were multinodular goiter (21.5%) and Graves' disease (7.7%). Significant immediate hypocalcemia was observed in 25 (38.5%) patients. Both iPTH4hr <12.5 pg/mL and %iPTH decline >72% could accurately predict significant immediate hypocalcemia. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for iPTH4hr were 92%, 87.5%, 82.1%, and 94.6%, respectively. The %iPTH decline was equal in accuracy, with sensitivity, specificity, PPV, and NPV of 84%, 90%, 84%, and 90%, respectively. At 6 months after surgery, 19 patients (29.2%) displayed permanent hypoparathyroidism. The iPTH4hr <12.5 pg/mL and %iPTH decline >72% could also predict permanent hypoparathyroidism, with sensitivity, specificity, PPV, and NPV of 100%, 80.4%, 67.9%, and 100%, and 94.7%, 84.8%, 72%, and 97.5%, respectively.

CONCLUSIONS

Only a single measurement of iPTH4hr could be helpful in identifying patients at risk of significant immediate hypocalcemia in need prompt treatment, and subsequently facilitating early discharge of patients. Also, this parameter can precisely predict permanent hypoparathyroidism.

IS THERE A RELATIONSHIP BETWEEN VITAMIN D STATUS AND HYPOCALCEMIA AFTER TOTAL THYROIDECTOMY?

Context

Vitamin D plays a crucial role in calcium metabolism through parathormone-dependent process. Deficiency of this important nutrient may be associated with hypocalcemia after thyroidectomy.

Objective

To evaluate the role of vitamin D in predicting hypocalcemia following total thyroidectomy.

Subjects and Methods

One hundred and fifty patients who underwent total thyroidectomy for benign or malignant thyroid disease were included in this prospective study. The association between preoperative vitamin D status and the development of hypocalcemia were investigated.

Results

Biochemical and symptomatic hypocalcemia were found in 28 (18.7%) and 22 (14.7%) patients, respectively. Preoperative vit D level was found significantly lower in patients with biochemical (p = 0.006) and clinical (p < 0.001) hypocalcemia in comparison to normocalcemic patients. The patients who had <10 ng/mL vit D level (severe deficiency) developed significantly more biochemical and clinical hypocalcemia than the patients with serum vit D level higher than 10 ng/mL (p = 0.030 and p < 0.001, respectively).

Conclusions

Although postthyroidectomy hypocalcemia is multifactorial, vit D deficiency, particularly severe form, is significantly associated with the development of biochemical and clinical hypocalcemia. Vit D supplementation can prevent this unwanted complication in such patients.

Seasonal Difference in Postthyroidectomy Hypocalcemia

Objective

Hypocalcemia following thyroidectomy often prolongs hospital stay and is potentially life-threatening. The objective of this study is to determine whether the season when thyroidectomy is performed is associated with postoperative hypocalcemia.

Study Design

Retrospective case series of patients undergoing thyroid surgery from 2009 to 2015.

Setting

Tertiary care academic institution in Montreal, Canada.

Subjects and Methods

A consecutive sample of 823 patients undergoing thyroidectomy by a single high-volume otolaryngologist for a suspected or confirmed thyroid malignancy. Patient demographics, procedure type, calcium and vitamin D supplementation, and seasonal rate of hypocalcemia postthyroidectomy were calculated and compared.

Results

Average seasonal rates of postthyroidectomy hypocalcemia in the winter, spring, summer, and autumn were, respectively, 8.3% (8 of 216), 7.3% (12 of 165), 1.5% (3 of 201), and 3.5% (8 of 228; P < .005). Patients operated in the winter were 5.6 times more likely to develop hypocalcemia as compared with those in the summer ( P < .01; 95% confidence interval: 1.7-18.7). In a multiple regression analysis factoring in season when surgery was performed, procedure type, and preoperative vitamin D/calcium supplementation, surgery occurring in the winter predicted a hypocalcemia event (correlation coefficient [SE]: 0.72 [0.024], P = .026; 0.006 [0.025], P = .81; 0.004 [0.019], P = .82, respectively).

Conclusion

In this study, patients undergoing thyroidectomy in the winter months were more likely to develop postoperative hypocalcemia when compared with those operated in the summer. Further studies are needed to understand the role of vitamin D in the observed seasonal difference in hypocalcemia rates.