Effects of Preoperative Iodine Administration on Thyroidectomy for Hyperthyroidism: A Systematic Review and Meta-analysis

TSH receptor antibody as a predictor of difficult robotic thyroidectomy in patients with Graves' disease

Thyroidectomy in Graves' disease can be challenging due to greater thyroid size and vascularity. While thyroid stimulating hormone receptor antibody (TRAb) level is associated with disease severity and thyroid vascularity, its impact on operative outcomes remains unclear. This study aimed to compare challenging factors for robotic thyroidectomy (RT) and open thyroidectomy (OT) in Graves' disease patients, including TRAb as a predictive factor for difficult thyroidectomy. This retrospective study included Graves' disease patients who underwent total thyroidectomy between September 2013 and January 2023. The clinical characteristics and operative outcomes were compared between patients who received OT and bilateral axillo-breast approach RT. Factors affecting operation time and estimated blood loss (EBL) were evaluated in both groups using regression analyses. A total of 85 patients received either OT (n = 48) or RT (n = 37). Median thyroid volumes in the OT and RT groups were 72.4 g and 57.6 g, respectively. Operation time was affected by thyroid volume in both groups. Additionally, higher thyroid hormone levels and bilateral central neck node dissection prolonged operation time in the RT group. EBL was marginally associated with thyroid volume in the OT group. However, in the RT group, TRAb level was independently associated with greater EBL (p = 0.04), while no significant association was found with thyroid volume. Predictive factors for difficult thyroidectomy differed by operation approaches. TRAb significantly predicted intraoperative bleeding in RT, while this association was absent in OT. Caution is warranted when performing RT on Graves' disease patients with high TRAb levels.

Outcomes of Preoperative Medical Therapy for Thyroidectomy in Autoimmune Thyroid Disease

INTRODUCTION

Thyroidectomy provides definitive treatment for autoimmune thyroid disease (AITD) often resulting in improved quality of life. Historically, patients with AITD undergoing thyroidectomy have increased rates of postoperative hypoparathyroidism and recurrent laryngeal nerve palsy. We investigated the outcomes of preoperative medications in patients with AITD undergoing thyroidectomy.

METHODS

We performed a retrospective analysis of patients who underwent thyroidectomy for AITD at a single institution from 2015 to 2021. Surgical outcomes and perioperative laboratory values were analyzed by type of AITD and type of preoperative medical treatment: none, saturated solution of potassium iodide (SSKI), corticosteroids, or both SSKI and corticosteroids.

RESULTS

A total of 123 patients underwent thyroidectomy for AITD and were included in analysis: 50 received no preoperative medications, 40 received SSKI, 20 received corticosteroids, and 13 received both. Seventy-six patients had Graves' disease and 47 had Hashimoto's thyroiditis. There were no significant differences in blood loss, operative time, wound complications, hematoma, or recurrent laryngeal nerve injury for patients treated with preoperative corticosteroids compared to those who were not. Patients who received corticosteroids and patients with Graves' disease more commonly had at least one instance of hypocalcemia postoperatively (P < 0.01, P = 0.01), although only on postoperative day 1 was mean calcium < 8.5 mg/dL. There was no difference in rate of transient or permanent hypoparathyroidism.

CONCLUSIONS

Patients who received corticosteroids preoperatively had no increased risk of complications. They did have mildly lower calcium levels in the early postoperative period, although no difference in hypoparathyroidism. Further exploration is warranted to investigate the impact of preoperative corticosteroids on operative difficulty, quality of life, and autoantibody clearance.

Hyperthyroidism: A Review

Importance

Overt hyperthyroidism, defined as suppressed thyrotropin (previously thyroid-stimulating hormone) and high concentration of triiodothyronine (T3) and/or free thyroxine (FT4), affects approximately 0.2% to 1.4% of people worldwide. Subclinical hyperthyroidism, defined as low concentrations of thyrotropin and normal concentrations of T3 and FT4, affects approximately 0.7% to 1.4% of people worldwide. Untreated hyperthyroidism can cause cardiac arrhythmias, heart failure, osteoporosis, and adverse pregnancy outcomes. It may lead to unintentional weight loss and is associated with increased mortality.

Observations

The most common cause of hyperthyroidism is Graves disease, with a global prevalence of 2% in women and 0.5% in men. Other causes of hyperthyroidism and thyrotoxicosis include toxic nodules and the thyrotoxic phase of thyroiditis. Common symptoms of thyrotoxicosis include anxiety, insomnia, palpitations, unintentional weight loss, diarrhea, and heat intolerance. Patients with Graves disease may have a diffusely enlarged thyroid gland, stare, or exophthalmos on examination. Patients with toxic nodules (ie, in which thyroid nodules develop autonomous function) may have symptoms from local compression of structures in the neck by the thyroid gland, such as dysphagia, orthopnea, or voice changes. Etiology can typically be established based on clinical presentation, thyroid function tests, and thyrotropin-receptor antibody status. Thyroid scintigraphy is recommended if thyroid nodules are present or the etiology is unclear. Thyrotoxicosis from thyroiditis may be observed if symptomatic or treated with supportive care. Treatment options for overt hyperthyroidism from autonomous thyroid nodules or Graves disease include antithyroid drugs, radioactive iodine ablation, and surgery. Treatment for subclinical hyperthyroidism is recommended for patients at highest risk of osteoporosis and cardiovascular disease, such as those older than 65 years or with persistent serum thyrotropin level less than 0.1 mIU/L.

Conclusions and Relevance

Hyperthyroidism affects 2.5% of adults worldwide and is associated with osteoporosis, heart disease, and increased mortality. First-line treatments are antithyroid drugs, thyroid surgery, and radioactive iodine treatment. Treatment choices should be individualized and patient centered.

Preoperative preparation for Graves' disease

Thyroidectomy is always regarded as the crucial treatment for Graves' disease, especially in cases of poor efficacy or excessive side effects of antithyroid- drugs and 131I radioiodine therapy. To decrease the incidence of hemorrhage, thyroid storms and other severe complications during the perioperative period, surgeons explore different therapies to prepare for thyroidectomy. We performed a review of preoperative preparation with a focus on the Graves' disease population. Most of the previous schemes are effective, which contributes to the smooth operation of patients, but there is no unified standard for preoperative preparation. This review aims to summarize the preoperative preparation of Graves' disease and the latest developments. Prospective studies with longer follow up-up periods are required to select appropriate preoperative regimens based on personal thyroid statements and to identify target populations of benefit.

Antithyroid Drugs in the Management of Graves' Disease: A Friend and Foe

Graves' disease is an autoimmune condition in which the patient develops autoantibodies that stimulate the thyroid gland, leading to thyrotoxicosis. We report the case of a 29-year-old female who presented one month postpartum with typical symptoms and signs of thyrotoxicosis. Biochemical and radiological investigations confirmed thyrotoxicosis due to Graves' disease. She received methimazole (MMI) treatment, leading to an allergic reaction in the form of a generalized rash on the body precluding its use. We later started the treatment with propylthiouracil, which she initially tolerated well. During her treatment, she became pregnant and delivered a baby girl by cesarean section at 37 weeks of gestation. The baby developed neonatal thyrotoxicosis due to the transplacental transmission of maternal thyrotropin receptor antibodies. Thyrotoxicosis was short-lived, without consequences, and treated with antithyroid drugs. Three months after delivery, thyroid hormone levels rose considerably, requiring higher doses of propylthiouracil, which resulted in severe hepatic dysfunction, and therefore we stopped the therapy. We admitted her to the hospital for rapid correction of thyroid hormones using steroids, supersaturated potassium iodide, and cholestyramine before she underwent a total thyroidectomy. Our case highlights the challenges the patients and clinicians can face while managing Graves' disease. We discuss the role of a multidisciplinary team approach to care and the options available for treatment in such difficult situations.

Effect of Lugol's solution on 131I therapy efficacy in Graves' disease

PURPOSE

Lugol's solution could control thyroid function and suppress ¹³¹I uptake in hyperthyroidism. This study aimed to investigate the appropriate time to withdraw Lugol's solution before ¹³¹I therapy (RIT) in Graves' disease (GD) patients, and how this should influence ¹³¹I uptake and RIT outcome.

METHODS

Two groups (125 cases and 1805 cases) of GD patients received RIT, who were pre-treated with and without Lugol's solution (RI-CI group and RI group). The RI-CI group was further divided into the following sub-groups depending on the duration span between Lugol's solution withdrawal and RIT: sub-group A, 4-7 d (n = 49); sub-group B, 8-14 d (n = 41); and sub-group C, 15-30 d (n = 35). The highest radioactive iodine uptake rate (RAIU_max), effective half-life (T_eff), TRAb, and free triiodothyronine (FT₃) and free thyroxine (FT₄) levels were compared, and therapeutic outcome was evaluated.

RESULTS

There were no significant differences in RAIU_max, TRAb, and T_eff among the four sub-groups (P > 0.05). Both FT₃ and FT₄ levels in sub-groups A and B were lower than those in group RI and sub-group C (P < 0.05). The outcome of non-hyperthyroidism (euthyroidism + hypothyroidism) in groups RI-CI and RI was significantly different at post-RIT month 1 and 3 (P < 0.05). However, intergroup differences at 6 and 12 months were not significant (P > 0.05).

CONCLUSIONS

Withdrawal of Lugol's solution 4-7 or 8-14 d before RIT does not influence ¹³¹I uptake and RIT efficacy in GD. Moreover, in order to avoid a rapid increase in thyroid hormone levels at the same time, Lugol's solution should be withdrawn 4-7 d before RIT.

Potassium Iodide Tablets Instead of a Saturated Solution Preoperatively for Reaching Euthyroidism Quickly in Refractory Graves' Disease

The optional use of a saturated solution of potassium iodide in the immediate preoperative period to reach euthyroidism is included both in the American Thyroid Association (ATA) and in the European Thyroid Association (ETA) guidelines for the treatment of Graves' disease (GD). The recent literature though, shows that it does not translate to more clinically meaningful differences in surgical outcome. In our experience, potassium iodide should not be seen as a means for reducing operative time or complications; it is an effective way for reaching euthyroidism quickly. Herein, we describe three selected cases in which concentrated potassium iodide 65 mg tablets - instead of a saturated solution - were administered for thyroid blocking preoperatively, as recommended in the event of a nuclear emergency. One of the patients was pregnant. After oral treatment with potassium iodide 130 mg daily (two pills), euthyroidism was reached in all three cases within 24 hours. There were no side effects and surgery was performed without complications. Although the current literature did not report a significant benefit concerning operative time and complications, in our opinion preoperative potassium iodide plays an important role in selected cases for reaching euthyroidism preoperatively quickly. Potassium iodide 65 mg tablets, which are recommended in case of a nuclear emergency, are a very effective alternative to saturated solutions, which are not always quickly available and generally need to be administered over seven to 10 days.

Efficacy and safety of preoperative preparation with Lugol's iodine solution in euthyroid patients with Graves' disease (LIGRADIS Trial): Study protocol for a multicenter randomized trial

Background

Currently, both the American Thyroid Association and the European Thyroid Association recommend preoperative preparation with Lugol's Solution (LS) for patients undergoing thyroidectomy for Graves’ Disease (GD), but their recommendations are based on low-quality evidence. The LIGRADIS trial aims to provide evidence either to support or refute the systematic use of LS in euthyroid patients undergoing thyroidectomy for GD.

Methods

A multicenter randomized controlled trial will be performed. Patients ≥18 years of age, diagnosed with GD, treated with antithyroid drugs, euthyroid and proposed for total thyroidectomy will be eligible for inclusion. Exclusion criteria will be prior thyroid or parathyroid surgery, hyperparathyroidism that requires associated parathyroidectomy, thyroid cancer that requires adding a lymph node dissection, iodine allergy, consumption of lithium or amiodarone, medically unfit patients (ASA-IV), breastfeeding women, preoperative vocal cord palsy and planned endoscopic, video-assisted or remote access surgery.

Between January 2020 and January 2022, 270 patients will be randomized for either receiving or not preoperative preparation with LS. Researchers will be blinded to treatment assignment. The primary outcome will be the rate of postoperative complications: hypoparathyroidism, recurrent laryngeal nerve injury, hematoma, surgical site infection or death. Secondary outcomes will be intraoperative events (Thyroidectomy Difficulty Scale score, blood loss, recurrent laryngeal nerve neuromonitoring signal loss), operative time, postoperative length of stay, hospital readmissions, permanent complications and adverse events associated to LS.

Conclusions

There is no conclusive evidence supporting the benefits of preoperative treatment with LS in this setting. This trial aims to provide new insights into future Clinical Practice Guidelines recommendations.

Trial registration

ClinicalTrials.gov identifier: NCT03980132.

Hemodynamic Instability during Thyroidectomy in Graves' Disease

BACKGROUND

The aim of this study was to investigate the changes in vital signs and hemodynamic status that occur in patients during the intraoperative course of thyroidectomy in Graves' Disease (GD).

METHODS

A total of 71 patients were included in the study. Patients were directed to surgery when they had large goiters with compressive symptoms or suspicious nodules, were pregnant or lactating, were unresponsive or intolerant to antithyroid drugs (ATDs), or expressed a preference to have surgery. All patients scheduled for operations underwent surgery while in the euthyroid state.

RESULTS

Hemodynamic instability was observed in 18 patients during thyroidectomy. Disease duration, sample weight, and thyroid-stimulating hormone receptor antibodies (TRAb) levels were found to be effective on hemodynamic instability. Logistic regression analysis revealed an 11-fold increase in the instability risk in patients with a period of disease shorter than 21 months (P = 0.037). A TRAb value >11.5 increased the risk by 235fold (p < 0.001).

CONCLUSION

High levels of TRAb values and new onset of disease with shorter periods of ATDs use may be risk factors for hemodynamic instability during thyroidectomy. Patients with larger thyroid glands are at greater risk for instability during surgery. Those risks should be taken into account during surgery, and the surgical and anesthetic management of the patient should be made more carefully in concordance with the anesthesia team.

Effect of preoperative potassium iodide administration on Graves' disease surgery: a propensity score analysis

BACKGROUND

Preoperative administration of a saturated solution of potassium iodide (SSKI) is recommended in the guidelines for the management of hyperthyroidism due to Graves' disease. Studies addressing its effect on complications after thyroidectomy are inconclusive.

METHODS

Retrospective multicenter Propensity Score study of patients undergoing total thyroidectomy for Graves' disease, from January 2013 to September 2019 in two tertiary centers in Madrid, Spain. Patients were given SSKI prior to surgery or not according to surgeons' preferences. Electronic clinical records were reviewed searching: baseline characteristics surgical variables, pathological findings, and postoperative complications.

RESULTS

Ninety patients were analyzed: 44 received SSKI and 46 were not given SSKI. No significant differences were found in the main postoperative complications with or without SSKI: transient hypoparathyroidism (40.9% vs. 50%), permanent hypoparathyroidism (6.8% vs. 13%), transient recurrent laryngeal nerve (RLN) palsy (2.3% vs. 8.7%), definitive RLN palsy (2.3% vs. 2.2%), or cervical hematoma (2.3% vs. 4.3%).

CONCLUSION

Preoperative administration of SSKI had no impact on postoperative complications after thyroidectomy for Graves' disease.

Preoperative Potassium Iodide Treatment in Patients Undergoing Thyroidectomy for Graves' Disease-Perspective of a European High-Volume Center

BACKGROUND

Potassium iodide (KI) treatment affects the vascularity of the thyroid gland and therefore may improve intraoperative visualization of essential structures. However, clear evidence for its usage is lacking, and its implementation in patients suffering from Graves' disease is becoming rare. The objective of this retrospective study was to assess the impact of KI treatment on the intraoperative course and the outcome of patients undergoing thyroidectomy for Graves' diseases.

METHODS

The study included 442 patients: 125 patients (28.3%) who received a preoperative treatment with KI ("Group KI") and 317 patients (71.7%) without a KI therapy ("Group No-KI"). Indication for KI treatment was a thyroid bruit (82.5%), as well as hyperthyroidism refractive to medical treatment with antithyroid drugs (17.4%).

RESULTS

All patients underwent total thyroidectomy. Permanent vocal cord paresis and permanent hypoparathyroidism were similar in both groups. KI treatment was associated with a significantly longer operative time (142 vs. 128 min, p < 0.001) and a significant higher weight of the thyroid gland. KI treatment did not impact duration of hospital stay or occurrence of secondary hemorrhage.

CONCLUSIONS

The complication rate of this study population with clinically severe GD was very low-which may be caused by pre-treatment of patients. The complementary option of a potassium iodide treatment before surgery remains a possibility and should be implemented individually.