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

Abstract

INTRODUCTION Techniques for thyroidectomy have evolved remarkably over the past 150 years. This is currently considered to be a very safe operation with favorable results when performed by experienced surgeons. 1 Hypocalcemia as a result of hypoparathyroidism is the most common postoperative complication of thyroidectomy. Hypoparathyroidism is considered to be transient if recovery occurs within days, weeks or a few months; or permanent when calcium levels do not return to normal within six months after surgery. 2,3 Transient hypoparathyroidism is seen in 0.3 to 49% of the patients undergoing thyroidectomy, whereas permanent hypoparathyroidism is less likely and has been reported in up to 13% of the cases. 4-8 The established risk factors for hypoparathyroidism after total thyroidectomy are advanced age, female sex, size of the thyroid gland, substernal goiter, Graves' disease, surgical technique (de-vascularization, excision or other inadvertent damage of the parathyroid glands), central compartment dissection, reoperation, less experienced surgeon and low 25-hydroxyvitamin D serum levels in the preoperative period. 9-18 Most thyroid surgeons provide calcium supplementation based on postoperative calcium, parathyroid hormone (PTH) serum levels, or presence of symptoms, whereas others routinely prescribe calcium and vitamin D supplementation after thyroidectomy to prevent hypocalcemia symptoms. 12,13,19 In a randomized study involving 143 patients undergoing total thyroidectomy, it

Adverse Events in Thyroid Surgery. Observational Study in Three Surgical Units With High Volume/Year.

“…The main cause of hypocalcemia after thyroidectomy appears to be hypoparathyroidism. (30)(31)(32) Lymph node dissection and female gender are associated with this complication, as previously suggested in case series, but parathyroid function recovery is not affected by these factors. (33)(34)(35)(36) Considering the lack of association between the accidental removal of parathyroid glands and the onset of paresthesias, which however correlate with the levels of calcium in the rst postoperative day, our study seems to suggest that postoperative hypocalcemia depends on numerous surgical and personal factors of the patient, di cult to predict.…”

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

“…18,21 Seven studies analysed the influence of malignant thyroid surgery. 3,9,10,17,27,29,34 Patients receiving malignant thyroid surgery showed a higher risk of postoperative hypocalcaemia ( P < 0.00001, OR = 1.85, 95% CI 1.83, 1.87) (Figure 6). Six studies analysed the influence of central neck dissection (CND).…”

“…3,9,10,[15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] The quality of all included studies was assessed using the NOS, of which 10 studies were rated as high quality (four with 8 stars and six with 7 stars) and 13 studies were rated as moderate quality (11 with 6 stars and two with 5 stars) (Table 1). 3,9,10,[15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] According to the heterogeneity for the meta-analyses on preoperative vitamin D levels (I 2 ¼ 74%, P ¼ 0.010), preoperative PTH (I 2 ¼ 92%, P < 0.0001) and preoperative calcium levels (I 2 ¼ 79%, P < 0.0009), a random-effects model was used for the meta-analyses. According to the heterogeneity for the meta-...…”

“…CI, confidence interval. 3,9,10,17,27,29,34 Figure 7. Forest plot of a meta-analysis to evaluate the relationship between central neck dissection and the risk for postoperative hypocalcaemia after thyroidectomy in adult patients.…”

“…CI, confidence interval. 3,17,22,25,27,29,34 boosts the release of calcitonin due to the large surgical scope of malignant thyroid disease and the need for lymph node dissection, leading to a decrease in blood calcium. 38 In addition, the parathyroid glands, especially the two pairs of parathyroid glands in the lower pole, are not easy to retain during total thyroidectomy for lymph node dissection because the upper parathyroid glands are located on the posterior and upper side of the upper pole of the thyroid.…”