Permanent hypocalcemia in patients operated for thyroid carcinoma

Investigating the Effect of Topical Dexamethasone at the Site of Thyroid Surgery (on the Parathyroids) on Blood Calcium Levels after Surgery, Compared to the Control Group in Patients who Underwent Total Thyroidectomy

BACKGROUND

Considering the side effects of systemic injection of dexamethasone, we decided to investigate the effect of local spraying of dexamethasone in the thyroid site after thyroidectomy on postoperative calcium levels in patients who undergo total thyroidectomy.

MATERIALS AND METHODS

The present investigation was a randomized clinical trial of dexamethasone on 60 patients undergoing thyroidectomy, who were assigned to two groups, namely the dexamethasone and control groups, each including 30 patients. Age, gender, type of underlying pathology was recorded in medicine. Also, the blood calcium level was recorded before surgery, 6, 24 and 48 hours after thyroidectomy. Statistical analysis was performed with SPSS version 20 using tests including t-test, paired t-test, Chi-squared, and repeated measures ANOVA.

RESULTS

On average, the 24-hour postoperative calcium level was found to be significantly different between the two groups (P0.001). Nevertheless, no such difference was found to exist between the average calcium level 6 and 48 hours after the operation (P0.05). Additionally, we noted a marked difference between the average blood calcium level, before and 48 hours after the operation, in both investigated groups (P0.05).

CONCLUSION

Accordingly, local spraying of dexamethasone in the thyroid site, after thyroidectomy, is effective on the calcium level after the operation and reduces the rate of hypocalcemia 24 hours after the operation.

Risk factors for postoperative hypocalcaemia after thyroidectomy: A systematic review and meta-analysis

Objective

A meta-analysis to investigate the risk factors for postoperative hypocalcaemia after thyroidectomy in adult patients.

Methods

A systematic search of publications in the electronic databases (PubMed®, The Cochrane Library, Web of Science, OVID and Embase®) from inception to June 2020 was conducted. Screening of titles, abstracts and full texts and data extraction were independently performed by two authors. The OR was selected as the pooled estimate.

Results

The analysis included 23 studies. Twelve significant risk factors for postoperative hypocalcaemia were identified: hypoparathyroidism, OR 5.58; total thyroidectomy, OR 3.59; hypomagnesaemia, OR 2.85; preoperative vitamin D deficiency, OR 2.32; female sex, OR 1.49; thyroid malignancy, OR 1.85; thyroiditis, OR 1.48; substernal multinodular goitres, OR 1.70; parathyroidectomy, OR 1.58; central compartment neck dissection, OR 1.17; modified radical neck dissection, OR 1.57; and central neck dissection, OR 1.54.

Conclusions

This meta-analysis provides moderate-to-high quality evidence that the 12 risk factors were predictive of postoperative hypocalcaemia, which should be monitored closely before thyroidectomy.

Clinical Utility of Preoperative Vitamin D3 Injection for Preventing Transient Hypocalcemia after Total Thyroidectomy

BACKGROUND

Postoperative transient hypocalcemia (TH) is a common complication of total thyroidectomy. This retrospective study evaluated the clinical utility of preoperative vitamin D3 injection for the prevention of TH after total thyroidectomy.

METHODS

We included 2294 patients who underwent total thyroidectomy from January 2015 until October 2018 and retrospectively analyzed their data by complete chart review at our hospital. The patients were divided into two groups: vitamin D3 injection (VDI; n = 342) and vitamin D3 noninjection (VDN; n = 1952). TH was defined as serum calcium <8.2 mg/dL and signs or symptoms of hypocalcemia.

RESULTS

The mean preoperative serum 25-hydroxyvitamin D (25-OHD) levels of the VDI group were significantly lower than those of the VDN group (16.5 ± 6.9 ng/mL vs 19.4 ± 8.7 ng/mL, p < 0.001). Multivariate analysis indicated that the significant risk factors of TH include vitamin D noninjection (hazard ratio (HR): 1.717, 95% confidence interval (CI): 1.282-2.300, p < 0.001), male gender (HR: 1.427, 95% CI: 1.117-1.822, p = 0.004), and capsular extension (HR: 1.273, 95% CI: 1.011-1.603, p = 0.040).

CONCLUSIONS

Preoperative vitamin D3 injection significantly contributed to the prevention of TH after total thyroidectomy. Further prospective or multicenter studies must be conducted to determine the effect of vitamin D3 injection.

Risk factors and outcomes of incidental parathyroidectomy in thyroidectomy: A systematic review and meta-analysis

Introduction

Postoperative hypocalcemia is the most common complication of thyroidectomy. Incidental parathyroidectomy (IP) was thought to be associated with postoperative hypocalcemia. However, according to previous studies, the risk factors and clinical outcomes of IP remain controversial.

Methods

Eligible studies were searched in databases including PubMed, Web of Science, and EMBASE from January 1990 to September 2017. Articles focusing on the relationship between IP and postoperative hypocalcemia were included. The risk of publication bias was assessed using Begg’s test and Egger’s regression asymmetry test. Pooled analysis was performed to evaluate the effect of IP on postoperative hypocalcemia and related risk factors. Sensitivity analysis was also conducted to test the stability of our results. The effects of hypocalcemia type, permanent definition, IP incidence, total thyroidectomy, and malignancy operation were also examined using a further subgroup analysis.

Results

Thirty-five studies were finally included in the analysis after an exhaustive literature review. Pathology data demonstrate that incidental parathyroidectomy occurred in various locations: intrathyroidal (2.2–50.0%), intracapsular (16.7–40.0%) and extracapsular (15.7–81.1%) regions. Overall, the analysis found that malignancy (RR = 1.60, 95% CI: 1.27 to 2.02; p< 0.0001), central neck dissection (RR = 2.35, 95% CI: 1.47 to 3.75; p = 0.0004), total thyroidectomy (RR = 1.42, 95% CI: 1.20 to 1.67; p< 0.0001) and reoperation (RR = 1.81, 95% CI: 1.20 to 2.75; p = 0.005) were significant risk factors of IP in thyroid surgery. There was an obvious effect of IP on temporary/permanent (RR = 1.59, 95% CI: 1.37 to 1.84; p< 0.0001) and permanent (RD = 0.0220, 95% CI: 0.0069 to 0.0370; p = 0.0042) postoperative hypocalcemia. Sensitivity analysis showed that these results were robust. The subgroup analysis found that IP played a significant role in both biochemical and clinical hypocalcemia in thyroidectomy (p < 0.0001 and p = 0.0003, separately). The association of IP and permanent hypocalcemia using different definitions (6 months or more than 12 months) was also confirmed by the analysis. IP increased the incidence of temporary/permanent and permanent hypocalcemia for cases undergoing total thyroidectomy (40.4% vs 24.8% and 5.8% vs 1.4%, respectively). Thyroidectomy with IP was associated with more permanent hypocalcemia (RR = 3.10, 95% CI: 2.01 to 4.78; p< 0.0001) in malignant cases but was not associated with temporary/permanent hypocalcemia.

Conclusions

Malignancy, central neck dissection, total thyroidectomy and reoperation were found to be significant risk factors of IP. IP increases the risk of postoperative hypocalcemia after thyroidectomy. We recommend a more meticulous intraoperative identification of parathyroid gland in thyroidectomy to reduce IP, particularly for total thyroidectomy and malignancy cases.

Mechanisms behind Post-Thyroidectomy Hypocalcemia: Interplay of Calcitonin, Parathormone, and Albumin-A Prospective Study

PURPOSE OF STUDY

Hypocalcemia after thyroidectomy is attributed to injury or ischemia to parathyroid glands. Transient hypocalcemia in thyroidectomy when parathyroids are preserved is not adequately explained. Release of calcitonin and hypoalbuminemia are two proposed reasons. Primary objective of this study was to find the change in calcitonin in the postoperative period after total thyroidectomy. Secondarily, hypocalcemia and its correlation with calcitonin, albumin, and parathormone were also studied.

MATERIALS AND METHODS

This Cohort study was carried out at the general surgical department of a tertiary level teaching institution from April 2015 to December 2015. One hundred adult patients undergoing total thyroidectomy, with at least three parathyroids being preserved were included. Changes in calcium, calcitonin, albumin, and parathormone were studied based on preoperative levels and the values at 1, 6, 24, and 48 hr after surgery.

RESULTS

Calcitonin increased at one hour after thyroidectomy and fell below preoperative levels subsequently. Parathormone showed a mild rise at one hour and normalized subsequently. Total calcium, corrected calcium, and albumin showed decline at one hour and recovered gradually over the next two days. At preoperative level, calcium had significant correlation with parathormone alone. Calcium levels at one hour had significant correlation with calcitonin. All post-operative calcium levels had significant correlation with parathormone and the number of parathyroids preserved in situ without auto-transplantation.

CONCLUSIONS

There is significant hypocalcemia within the first 24 hr after thyroidectomy, caused by calcitonin release and hypoalbuminemia. Preservation of maximum number of parathyroids in-situ can counter and normalize this hypocalcemia.