Surgical management of hyperthyroidism

Amiodarone Therapy: Updated Practical Insights

Amiodarone, a bi-iodinated benzofuran derivative, is among the most commonly used antiarrhythmic drugs due to its high level of effectiveness. Though initially categorized as a class III agent, amiodarone exhibits antiarrhythmic properties across all four classes of antiarrhythmic drugs. Amiodarone is highly effective in maintaining sinus rhythm in patients with paroxysmal atrial fibrillation while also playing a crucial role in preventing a range of ventricular arrhythmias. Amiodarone has a complex pharmacokinetic profile, characterized by a large volume of distribution and a long half-life, which can range from several weeks to months, resulting in prolonged effects even after discontinuation. Side effects may include thyroid dysfunction, pulmonary fibrosis, and hepatic injury, necessitating regular follow-ups. Additionally, amiodarone interacts with several drugs, including anticoagulants, which must be managed to prevent adverse effects. Therefore, a deep understanding of both oral and intravenous formulations, as well as proper dosage adjustments, is essential. The aim of this paper is to provide a comprehensive and updated review on amiodarone's indications, contraindications, recommended dosages, drug interactions, side effects, and monitoring protocols.

Amiodarone-induced thyrotoxicosis: Should surgery be considered?

Amiodarone is the most widely prescribed antiarrhythmic drug worldwide, but induces thyrotoxicosis or hypothyroidism in 15 to 20% of patients. Hyperthyroidism is less frequent than hypothyroidism, and two types of thyrotoxicosis are distinguished according to presence of underlying thyroid disease. Diagnosis is made in case of low TSH and high levels of T3 and T4. Initial treatment is based on anti-thyroid drugs and/or glucocorticoids. Some patients do not respond to medication, which increases the time spent with hyperthyroidism. A long interval between diagnosis and euthyroidism and low left ventricular ejection fraction (LVEF) are predictive of major adverse cardiovascular events. Here, after describing the current state of knowledge of amiodarone-induced thyrotoxicosis, we analyze the literature on the impact of surgery. We suggest that early surgery should be the first option in case of ineffective medical treatment or LVEF<40%. In expert centers, surgical morbidity is no longer different than in other indications for thyroidectomy.

[Definitive treatment of Graves' disease in children]

BACKGROUND

Hyperthyreoidism due to Graves' disease is a rare disorder in pediatric practice. There is 2 treatment options in Graves' disease: medical treatment and definitive treatment, including surgery and radioactive iodine. Each method has its advantages and disadvantages. If medical therapy is ineffective the choice between radical treatment method is raised: radioactive iodine or total thyroidectomy. In this research we analyze treatment outcomes in pediatric Graves' disease patients after different radical treatment methods.

AIM

Comparative analysis of radical treatment outcomes in pediatric patients with Graves' disease.

MATERIALS AND METHODS

Retrospective and prospective one-center research of 122 patients with Graves' disease after radical treatment (between 2016 and 2021)RESULTS: The mean age was 13.5±3,5 year at the moment of examination. Patients were divided into 2 groups due to the radical treatments method: 1 group (n=60) were children after surgical treatment, 2 group (n=62) - after radioactive iodine. The mean dose of medical treatment in these groups did not reliably differ (p=0,06), duration of the medical treatment was reliably longer in patients after radioactive iodine (p=0,024). Graves' orbitopathy was diagnosed in 58 patients (47,5%) and met equally often in both groups, but active stage of Graves' orbitopathy was diagnosed only in patients from the 1st group. Thyroid size was reliable bigger in patients from the 1st group (p=0,004), and thyroid gland nodes were diagnosed only in patients from 1st group (p=0,0007).

CONCLUSION

RI can be considered an effective and safe treatment for GD. The effectiveness of RI depends on the volume of the thyroid gland; according to the results of the constructed ROC curve, the risk of repeated RI is higher with a volume of more than 55 cm3. Also radioactive iodine is undesirable if there is signs of ophatalmopathy due to its possible deterioration. According to the results of the study hypoparathyroidism after surgical treatment was diagnosed in 20%, recurrent laryngeal nerve injury was diagnosed after surgical treatment in 5% of patients. In patients with identified nodular goiter according to the results of ultrasound, surgical treatment is preferable due to the impossibility of excluding thyroid cancer.

The American Association of Endocrine Surgeons Guidelines for the Definitive Surgical Management of Thyroid Disease in Adults

OBJECTIVE

To develop evidence-based recommendations for safe, effective, and appropriate thyroidectomy.

BACKGROUND

Surgical management of thyroid disease has evolved considerably over several decades leading to variability in rendered care. Over 100,000 thyroid operations are performed annually in the US.

METHODS

The medical literature from 1/1/1985 to 11/9/2018 was reviewed by a panel of 19 experts in thyroid disorders representing multiple disciplines. The authors used the best available evidence to construct surgical management recommendations. Levels of evidence were determined using the American College of Physicians grading system, and management recommendations were discussed to consensus. Members of the American Association of Endocrine Surgeons reviewed and commented on preliminary drafts of the content.

RESULTS

These clinical guidelines analyze the indications for thyroidectomy as well as its definitions, technique, morbidity, and outcomes. Specific topics include Pathogenesis and Epidemiology, Initial Evaluation, Imaging, Fine Needle Aspiration Biopsy Diagnosis, Molecular Testing, Indications, Extent and Outcomes of Surgery, Preoperative Care, Initial Thyroidectomy, Perioperative Tissue Diagnosis, Nodal Dissection, Concurrent Parathyroidectomy, Hyperthyroid Conditions, Goiter, Adjuncts and Approaches to Thyroidectomy, Laryngology, Familial Thyroid Cancer, Postoperative Care and Complications, Cancer Management, and Reoperation.

CONCLUSIONS

Evidence-based guidelines were created to assist clinicians in the optimal surgical management of thyroid disease.

Incidences of Hypothyroidism Associated With Surgical Procedures for Thyroid Disorders: A Nationwide Population-Based Study

Background and Aim: Limited information available about different types of thyroid surgeries with risk for postoperative hypothyroidism. This study aimed to investigate the risk of developing early and late-onset postoperative hypothyroidism in patients with thyroid disorders. Methods: We used a large cohort data from the Taiwan National Health Insurance Research Data Base (NHIRDB) and identified 9,693 (9, 348) patients from January 1998 to December 2010, admitted for thyroid disorder surgeries. We used the surgical procedures time as the index date. Our observational retrospective cohort study excluded the subjects diagnosed with hypoparathyroidism and hypothyroidism before any surgeries. We analyzed the data using the Cox regression model to calculate the hazard ratio. Result: Postoperative hypothyroidism associated with bilateral-total (HR, 4.27; 95% CI, 3.32-5.50), one-side total and another subtotal (HR, 3.16; 95% CI, 2.59-3.86), bilateral-subtotal (HR, 1.65; 95% CI, 1.37-1.98), and unilateral-total (HR, 1.17; 95% CI, 0.95-1.44) surgical procedures. The time intervals for thyroid disorders were 320 cases developed postoperative hypoparathyroidism in eight weeks, 480 cases the second month, and 1000 cases in the first year after surgery. Conclusion: Findings suggest that thyroidectomy was associated with transient postoperative hypothyroidism in thyroid disorder patients. The bilateral-total surgical procedure was strongly associated with temporary postoperative hypothyroidism.

Amiodarone and thyroid physiology, pathophysiology, diagnosis and management

Although amiodarone is considered the most effective antiarrhythmic agent, its use is limited by a wide variety of potential toxicities. The purpose of this review is to provide a comprehensive "bench to bedside" overview of the ways amiodarone influences thyroid function. We performed a systematic search of MEDLINE to identify peer-reviewed clinical trials, randomized controlled trials, meta-analyses, and other clinically relevant studies. The search was limited to English-language reports published between 1950 and 2017. Amiodarone was searched using the terms adverse effects, hypothyroidism, myxedema, hyperthyroidism, thyroid storm, atrial fibrillation, ventricular arrhythmia, and electrical storm. Google and Google scholar as well as bibliographies of identified articles were reviewed for additional references. We included 163 germane references in this review. Because amiodarone is one of the most frequently prescribed antiarrhythmic drugs in the United States, the mechanistic, diagnostic and therapeutic information provided is relevant for practicing clinicians in a wide range of medical specialties.

Increased risk of postoperative complications after total thyroidectomy with Graves' disease

BACKGROUND

The effect of Graves' disease on the risk of postoperative complications in patients undergoing total thyroidectomy is unclear.

METHODS

The incidence of recurrent laryngeal nerve (RLN) injury and hypoparathyroidism were analyzed between 165 patients with Graves' disease (GD group) and 1:1 matched patients with euthyroid states (control group).

RESULTS

The matched cohorts did not differ in age, sex, body mass index, pathologic diagnosis, and extent of operation. Excised thyroid weight was higher in the Graves' disease than in the control group (60.1 g vs 22.6 g; P < .001). Multivariate analysis showed that Graves' disease significantly increased risks of transient RLN injury (odds ratio [OR] = 4.7, 95% confidence interval [CI] = 1.5-15.5; P = .010) and transient hypoparathyroidism (OR = 2.8, 95% CI = 1.3-5.8; P = .007). Rates of permanent complications were comparable in the Graves' disease and control groups.

CONCLUSIONS

Graves' disease can be a predictive factor for postoperative RLN injury and hypoparathyroidism after total thyroidectomy.

Incidental thyroid carcinoma in surgery-treated hyperthyroid patients with Graves' disease: a systematic review and meta-analysis of cohort studies

Background

The association between Graves’ disease (GD) and thyroid carcinoma remains controversial. This study aimed to investigate incidental thyroid carcinoma (ITC) in surgery-treated hyperthyroid patients with and without GD.

Materials and methods

We searched PubMed and EMBASE for cohort studies investigating ITC in surgery-treated hyperthyroid patients without prediagnosed thyroid carcinoma in accordance with the Meta-Analysis of Observational Studies in Epidemiology guidelines. The last search was updated to January 23, 2018. All statistical tests were performed using Review Manager 5.3 and STATA version 12.0.

Results

Eleven cohort studies involving 10,743 GD and 3,336 non-GD patients were included. The pooled prevalence of ITC was 7.0% (95% confidence interval [CI] 4.5–9.6), and was comparable in surgery-treated GD and non-GD hyperthyroid patients (GD vs non-GD: pooled odds ratio [OR], 1.0; 95% CI: 0.68–1.46; P=0.98). In the subgroup analysis, toxic adenoma and toxic nodular goiter showed no difference when comparing with GD (pooled OR, 0.53; 95% CI: 0.21–1.36; P=0.18 and pooled OR, 1.01; 95% CI: 0.65–1.57; P=0.95, respectively).

Conclusion

Our study demonstrated that GD was not associated with increased risk of ITC in surgery-treated hyperthyroid patients.

Postoperative Outcomes in Graves' Disease Patients: Results from the Nationwide Inpatient Sample Database

BACKGROUND

Current surgical indications for Graves' disease include intractability to medical and/or radioablative therapy, compressive symptoms, and worsening ophthalmopathy. Total thyroidectomy for Graves' disease may be technically challenging and lead to untoward perioperative outcomes. This study examines outcomes in patients with Graves' disease who underwent total thyroidectomy and assesses its safety for this patient population.

METHODS

A retrospective cross-sectional analysis was performed using the Nationwide Inpatient Sample database from 2006 to 2011. Total thyroidectomy performed in patients with Graves' disease, benign multinodular goiter (MNG), and thyroid cancer was identified. Demographic factors, comorbidities, and postoperative complications were evaluated. Chi-square, one-way analysis of variance, and risk-adjusted multivariable logistic regression were performed.

RESULTS

Of 215,068 patients who underwent total thyroidectomy during the study period, 11,205 (5.2%) had Graves' disease, 110,124 (51.2%) MNG, and 93,739 (43.6%) thyroid malignancy. Patients with Graves' disease were younger than MNG and thyroid cancer patients (M_age = 42.8 years vs. 55.5 and 51.0 years; p < 0.01). The Graves' disease group included a higher proportion of women (p < 0.01) and nonwhites (p < 0.01). Postoperatively, Graves' patients had significantly higher rates of hypocalcemia (12.4% vs. 7.3% and 10.3%; p < 0.01), hematomas requiring reoperation (0.7% vs. 0.4% and 0.4%; p < 0.01), and longer mean hospital stay (2.7 days vs. 2.4 and 2.2 days; p < 0.01) compared to MNG and thyroid cancer patients, respectively. On risk-adjusted multivariate logistic regression, Graves' disease was independently associated with a higher risk of vocal-cord paralysis (odds ratio [OR] = 1.36 [confidence interval (CI) 1.08-1.69]), tracheostomy (OR = 1.35 [CI 1.1-1.67]), postoperative hypocalcemia (OR = 1.65 [CI 1.54-1.77]), and hematoma requiring reoperation (OR = 2.79 [CI 2.16-3.62]) compared to MNG patients. High-volume centers for total thyroidectomy were independently associated with lower risk of postoperative complications, including in patients with Graves' disease.

CONCLUSIONS

Despite low overall morbidity following total thyroidectomy, Graves' disease patients are at increased risk of postoperative complications, including bleeding, vocal-cord paralysis, tracheostomy, and hypocalcemia. These risks appear to be lower when performed at high-volume centers, and thus referral to these centers should be considered. Total thyroidectomy may therefore be a safe treatment option for appropriately selected patients with Graves' disease when performed by experienced surgeons.