Assessment of calcium homeostasis after total thyroidectomy in differentiated thyroid carcinoma

Naresh K Panda; Gyanaranjan Nayak; Roshan K Verma; Jaimanti Bakshi; Abhijeet Singh; S Anand

doi:10.4103/jhnps.jhnps_14_17

ORIGINAL ARTICLE

Year : 2017 | Volume : 5 | Issue : 2 | Page : 79-81

Assessment of calcium homeostasis after total thyroidectomy in differentiated thyroid carcinoma

Naresh K Panda, Gyanaranjan Nayak, Roshan K Verma, Jaimanti Bakshi, Abhijeet Singh, S Anand
Department of Otolaryngology Head and Neck Surgery, Postgraduate Institute of Medical Education and Research, Chandigarh, India

Date of Web Publication

22-Jan-2018

Correspondence Address:
Prof. Naresh K Panda
Department of Otolaryngology Head and Neck Surgery, Postgraduate Institute of Medical Education and Research, Postgraduate Institute of Medical Education and Research, Chandigarh - 160 015
India

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/jhnps.jhnps_14_17

Abstract

Background: After total thyroidectomy, hypocalcaemia can be transient or permanent. Most of the patients are being prescribed long term calcium supplementation despite preserving parathyroid glands. We have tried to study the various calcium homeostatic factors to predict the long term calcium levels in differentiated thyroid carcinoma following total thyroidectomy. Method: Study was conducted in a tertiary care centre and a total number of 28 patients of differentiated thyroid carcinoma were retrospectively analysed who underwent surgery from 2013 - 2015. Post surgery patients were given thyroxine and calcium supplementation with regular monitoring of thyroid function test and serum calcium. Serum Parathormone(PTH) levels were recorded after minimum of one year of completion of surgery. Results: Out of 28 patients, 26 patients have serum parathormone within normal range (15-65 pg/ml). Only two patients have low serum PTH values (<15pg/ml). Total number of 23 patients are taking calcium supplementation out of which 21 patients have normal parathormone value. None of the patients without calcium supplementation have low parathormone levels. Conclusion: Our study reveals optimum calcium homeostasis in patients undergoing total thyroidectomy. A long term follow up of these patients is required so that many patients with normal PTH levels may not require calcium supplementation.

Keywords: Calcium metabolism, hypocalcemia, thyroid surgery

How to cite this article:
Panda NK, Nayak G, Verma RK, Bakshi J, Singh A, Anand S. Assessment of calcium homeostasis after total thyroidectomy in differentiated thyroid carcinoma. J Head Neck Physicians Surg 2017;5:79-81

How to cite this URL:
Panda NK, Nayak G, Verma RK, Bakshi J, Singh A, Anand S. Assessment of calcium homeostasis after total thyroidectomy in differentiated thyroid carcinoma. J Head Neck Physicians Surg [serial online] 2017 [cited 2022 Jun 28];5:79-81. Available from: https://www.jhnps.org/text.asp?2017/5/2/79/223758

Introduction

One of the most common complications after total thyroidectomy is hypocalcemia ^[1],[2] with incidence ranging from 10% to 50% for transient hypocalcemia and 0%–2% for permanent hypocalcemia.^{[1],[2],[3],[4]} With the recent trends in avoiding prolonged patient stay at hospital ^[5],[6] and preferring discharges within 24 h, it is essential to identify the at-risk patients of hypocalcemia so as to prevent their emergency ward visit after total thyroidectomy.^[5],[6],[7] Although its etiology is multifactorial, the most frequent cause of hypocalcemia is hypoparathyroidism due to accidental excision or devascularization of the parathyroid glands. As compared to other complications such as recurrent laryngeal nerve injury and neck hematoma that presents in the first 24 h, the hypocalcemia nadir usually occurs by 24–48 h postoperatively; further creating a diagnostic dilemma and prolonging hospital stay.^[8] The variable frequency of occurrence of symptoms and lack of appropriate parameters for timely prediction of occurrence and duration of symptoms and need for prolonged medication poses further management challenge.^{[9],[10],[11]} Of the several studies in literature proposing management of hypocalcemia, following thyroidectomy, perioperative parathyroid monitorin, and preoperative Vitamin D level monitoring as a predictor of postoperative hypocalcemia looks promising.^{[12],[13],[14],[15],[16]}

Our article aims to present our experience in the management of long-term calcium homeostasis after thyroid surgery for differentiated thyroid cancers.

Methods

A retrospective analysis of 28 patients who underwent total and completion thyroidectomy for differentiated thyroid carcinoma between period 2013 and 2015 was performed. Following surgery, patients were given thyroxine and calcium supplementation with regular monitoring of thyroid function test and serum calcium. All the patient included in this study underwent meticulous thyroid gland dissection with the identification of recurrent laryngeal nerve and parathyroid gland. During the surgical procedure, the inferior thyroid artery trunk was identified and not ligated. In addition, the branch supplying the parathyroid gland was preserved. None of the patients underwent parathyroid gland transplantation and histopathology specimens did not receive any parathyroid gland. Intact parathormone (iPTH) levels were recorded after 1 year of completion of surgery. Analysis of data and statistics was done using Microsoft SPSS (International Business Machines Corp. New York) software.

Results

There were 25 patients of papillary carcinoma thyroid and 3 with follicular carcinomas as shown in [Table 1]. Out of 28 patients, 26 patients (92.8%) have serum parathormone within normal range (15–65 pg/ml) as shown in [Table 2]. Only two patients had low serum PTH values (<15 pg/ml). 23 patients (82.14%) were taking calcium supplementation out of which 21 patients had normal iPTH value at the end of 1 year. None of the patients without calcium supplementation have low parathormone levels.

Table 1: The distribution of surgery in differentiated thyroid carcinoma

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Table 2: Serum parathormone levels in patients at the end of 1 year of surgery

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Pearson's correlational analysis showed no significant correlation between patients on calcium supplementation and serum iPTH [Figure 1]. Chi-square test between completion and total thyroidectomy patient showed poor calcium control in completion thyroidectomy patients as compared to total thyroidectomy patients (P< 0.05).

Figure 1: Number of patients on calcium supplementation with respect to iPTH levels

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Discussion

Total thyroidectomy has been the standard of care for high-grade differentiated thyroid carcinoma. Total thyroidectomy procedure has various intraoperative as well as postoperative complications which can be early or as late as 6 months. Early postoperative hypocalcemia can cause tingling and numbness in perioral and fingertips and can progress to carpopedal spasm, laryngospasm, and tetani which is life-threatening. Causes of transient hypocalcemia are transient devascularization of parathyroid gland leading to transient hypoparathyroidism, calcitonin secretion into the circulation by manipulation of thyroid gland, and dilutional hypocalcemia. Patients in postoperative period require calcium supplementation along with Vitamin D. However, long-term calcium profile in such patients have never been studied.

Permanent hypoparathyroidism can be prevented by meticulous dissection near the parathyroid gland and inferior thyroid artery. Main branch of the inferior thyroid artery along with its branches to parathyroid gland needs to be identified and preserved which was carried out in all our patients. We use bipolar cautery forceps near the thyroid gland to cauterize fine branches of inferior thyroid artery supplying the thyroid gland preserving the main trunk.

In our study, 92.8% of patients have normal iPTH levels after 1 year of completion with 82% of patients on calcium supplementation. This data shows that in most of the patients parathyroid level comes back to normal. All these patients who had initial hypoparathyroidism have gradually recovered over the period which can range from 6 months to 1 year. Once the iPTH levels are found to be normal, it is not considered necessary to continue calcium supplementation.

Five out of 28 patients underwent completion thyroidectomy out of which only 1 patient has permanent hypoparathyroidism as compared to total thyroidectomy patients (1/23). Hypocalcemia in 1 patient of completion thyroidectomy was statistically significant. This data were in contrast to Merchavy et al. which showed lower rate of hypocalcemia in completion thyroidectomy patients.^[17] This can be explained as no of patients were more in their study, and all the completion thyroidectomy patients were previously operated in the same center.

Conclusion

Our study reveals optimum parathormone levels for calcium homeostasis in patients undergoing total thyroidectomy. Majority of patients do not require long-term calcium supplementation. Calcium supplementation hence can be stopped in the patients once their iPTH assumes normal levels A long-term prospective study with serial Pth levels and follow-up is required so that many patients with normal iPTH levels may not require calcium supplementation.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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