Determination of risk factors causing hypocalcaemia after thyroid surgery

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.

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.

Should Contralateral Nodules Be an Indication of Total or Completion Thyroidectomy for Patients With Unilateral Papillary Thyroid Carcinoma?

OBJECTIVE

To determine whether papillary thyroid carcinoma (PTC) patients with benign or nonsuspicious nodules in the contralateral lobe have a higher rate of recurrence or worse survival after lobectomy compared to those without nodules in the contralateral lobe.

METHODS

Adult patients who underwent lobectomy and were diagnosed with unilateral PTC (2013-2015), were identified from an institutional database. Patients who previously had cytologically benign nodules or nonsuspicious nodules in the contralateral lobe comprised the contralateral nodule (CN) group. Patients who did not have nodules in the contralateral lobe comprised the unilateral nodule (UN) group.

RESULTS

370 patients were included: 242 in the UN group and 128 in the CN group. After a median follow-up of 62 months (range, 16-85 months), recurrence was confirmed in 4.1% patients in the UN group and 5.5% patients in the CN group (p = 0.559). Clinical contralateral lobe PTC was detected in 2.9% (7/242) of patients from the UN group and 3.9% (5/128) of patients from the CN group (p = 0.601). The 5-year contralateral lobe recurrence-free survival (RFS) rates were 96.8% in the UN group and 97.4% in the CN group (p = 0.396). The 5-year loco-regional RFS rates were 98.4% in the UN group and 97.8% in the CN group (p = 0.690). The 5-year disease-specific survival rates were both 100%.

CONCLUSION

PTC patients with benign or nonsuspicious CNs have similar recurrence and survival rates after lobectomy compared to those without CNs. CNs alone should not be an indication for total or completion thyroidectomy.

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

Objectives:

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

Methods:

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

Results:

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

Conclusion:

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

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

OBJECTIVE

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

RESULTS

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

CONCLUSION

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