Efecto de la deficiencia de vitamina D sobre la hipocalcemia tras tiroidectomía total por bocio benigno

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.

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.

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.

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 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.

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.

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.

Clinical Pathway for Thyroidectomy

Clinical pathways are care plans applicable to patient care procedures that present variations in practice and a predictable clinical course. They are designed not as a substitute for clinical judgment, but rather as a means to improve the effectiveness and efficiency of the procedures. This clinical pathway is the result of a collaborative work of the Sections of Endocrine Surgery and Quality Management of the Spanish Association of Surgeons. It attempts to provide a framework for standardizing the performance of thyroidectomy, the most frequently performed operation in endocrine surgery. Along with the usual documents of clinical pathways (temporary matrix, variance tracking and information sheets, assessment indicators and a satisfaction questionnaire) it includes a review of the scientific evidence around different aspects of pre, intra and postoperative management. Among others, antibiotic and antithrombotic prophylaxis, preoperative preparation in hyperthyroidism, intraoperative neuromonitoring and systems for obtaining hemostasis are included, along with management of postoperative hypocalcemia.

Perioperative indicators of hypocalcemia in total thyroidectomy: the role of vitamin D and parathyroid hormone

BACKGROUND

Hypocalcemia is a common complication of thyroidectomy. The aim of this study was to identify risk factors for this problem.

METHODS

This prospective analysis included 111 patients undergoing total or completion thyroidectomy. Preoperative vitamin D levels and postoperative day 1 parathyroid hormone levels were analyzed for their predictive effects on postoperative hypocalcemia.

RESULTS

Patients with ionized calcium <4.4 mg/dL had significantly lower mean parathyroid hormone levels than normocalcemic patients (13.0 vs 28.4 pg/mL, P < .001). Parathyroid hormone levels were also significantly lower in symptomatic patients (11.0 vs 28.4 pg/mL, P < .001). Preoperative vitamin D level, body mass index, gender, and pathologic findings were not associated with low calcium levels or symptoms of hypocalcemia.

CONCLUSIONS

Younger age and low postoperative parathyroid hormone levels are predictive of symptomatic hypocalcemia. A parathyroid hormone level outside of the reference range may indicate a need for more aggressive postoperative calcium supplementation and treatment with activated vitamin D. Older patients with normal postoperative parathyroid hormone levels may be safely discharged with appropriate calcium supplementation.