Introduction

Thyrotoxicosis is a condition that occurs when there is an excessive production of the thyroid hormones, triiodothyronine (T3 thyroid hormone) and thyroxine (T4 thyroid hormone). These hormones normally regulate the body’s metabolism.^1,2 Thyrotoxicosis is often confused with hyperthyroidism; however, hyperthyroidism is a specific type of thyrotoxicosis.

Thyrotoxicosis can be caused by autoimmune diseases or excessive consumption of thyroid hormones via medications or supplements. The most common cause of thyrotoxicosis is known as Graves’ disease, in which the immune system produces antibodies (proteins that normally help the body fight off any infections) that cause the thyroid gland to overproduce thyroid hormones. Another cause could be due to medications such as amiodarone (used to treat arrhythmias), which may lead to an overactive thyroid.^1,2

Symptoms of thyrotoxicosis include mood swings, nervousness or anxiety, persistent fatigue, swelling in the neck caused by an enlarged thyroid glandgoitre), heart palpitations, and twitching or trembling.²

The main treatment options for thyrotoxicosis are:

• Antithyroid medications that stop the thyroid from overproducing thyroid hormones
• Radioiodine treatment - a type of radiotherapy that destroys some cells in the thyroid, therefore reducing the thyroid’s ability to produce excessive thyroid hormones
• Surgery - in some cases, it may be recommended to remove some or all of your thyroid, to prevent it from producing thyroid hormones² 

Although thyrotoxicosis can generally be treated with medications, surgical intervention might also be considered in the worst cases. His article will focus on the surgical treatments of thyrotoxicosis, including the types of surgery, preoperative concerns, the procedure itself, and postoperative issues.

Types of thyroidectomy

Thyroidectomy is the surgical term used to address the removal of the thyroid gland. Depending on the severity of thyrotoxicosis as well as underlying conditions contributing to the increased thyroid hormone levels, the type of surgery advised may vary. Three main types of surgery  could be suggested, including: 

• Total thyroidectomy involves removing the whole thyroid gland. As this is to remove the entire thyroid gland, patients would then go on lifelong medication to preserve the functions lost by total removal
• Partial thyroidectomy: also known as a near-total thyroidectomy. This is when most of the thyroid gland is removed, but a small portion is left behind. This small portion is left behind. which can aid in producing the thyroid hormones; however, not to the extent where there is an overproduction. Partial thyroidectomy: also known as a lobectomy or hemithyroidectomy, where half of the thyroid is removed³ 

Preoperative considerations

Before undergoing the surgery, patients are evaluated using a pre-operative test to determine which type of surgery is needed, as well as their suitability for the surgery. These preoperative tests also focus on reducing any risks during surgery.  

To elaborate further, before the surgery, a blood test will be conducted to check and analyse your thyroid function and calcium levels. Other blood tests may also be done to check your vitamin D, parathyroid hormone levels, as well as kidney function. To ensure you are fit to undergo the surgery, an X-ray of your heart may also be conducted to make sure the surgery won’t put any stress on your heart.^4,5 Depending on the thyroid hormone levels, patients may also be placed on antithyroid medications such as methimazole to reach something known as a ‘euthyroid state’. This is where the levels of thyroid hormones in the body are at a ‘normal’ level to prevent any complications that may arise.⁶ Non-selective beta-blockers such as propranolol may also be prescribed to control some symptoms of thyrotoxicosis.^3,6 

Although a thyroidectomy is quite a successful surgery,  some risks are discussed in detail need to be considered before the surgery. These include the risks of potential bleeding, infection, scarring (dependent on the approach)  and undergoing anaesthesia. It is also worth noting that patients would also have to consider any postoperative changes/treatment.⁴ 

Thyroidectomy - the surgical procedure

Thyroidectomy is a carefully planned surgical procedure due to the complex location of the thyroid as it has a vast supply of blood vessels, nerves, as well as its connection to lymph nodes. Factors such as patient positioning, anaesthesia administration, the amount of gland that needs to be removed, and the incision are crucial.³

To begin the surgery, patients are positioned in a specific way to ensure optimal access to the thyroid gland. Patients are normally positioned in a supine position (lying horizontally facing upwards) with their neck extended and head slightly elevated using a doughnut cushion. Key anatomical areas such as the thyroid and midline are also marked with a marker to ensure precision. This surgery is also conducted under general anaesthesia, so one is unconscious during the procedure, and it can take about 2-4 hours, depending on the size of your thyroid gland and the amount being removed. Surgeons may also choose to place an intraoperative nerve monitor to keep an eye on the vocal cords and nerves during surgery to ensure they are not affected during surgery.³  

Once prepped, the surgeons begin the procedure by making a horizontal incision; this is usually made based on the markings and a lower crease in your neck. By making the incision in a natural skin crease, scarring after surgery is reduced. During the procedure, the arteries connecting to the area of the thyroid being removed are normally sealed prior to removing the gland to minimise and avoid bleeding. Once it has been removed, the area of incision is closed either through staples, sutures (stitches) or glue, depending on how invasive the wound is. Some surgeons may also place some drainage tubes in the neck to ensure that all excess fluid is removed after surgery, which can be kept in for 24-48 hours. These steps are normally adapted from patient to patient, dependent on patient-specific anatomy and pathology.^3,5 

Postoperative care and recovery

Following a thyroidectomy, the patients may be able to return home on the same day or a few days after surgery. This varies from patient to patient and by the type of thyroidectomy done. For example, if a hemithyroidectomy is performed,  one may be discharged the same day. During this period in the hospital, continuous monitoring is essential to look out for any excessive bleeding or swelling, as well as to help manage any pain or discomfort experienced immediately after surgery.^3,5 In addition, the patients may notice some hoarseness in their voice, which is usually temporary. If the problem persists, a postoperative vocal cord examination is conducted to find the cause.⁵

After surgery, patients are also monitored for any symptoms of hypocalcemia (low calcium levels), as it is the most common complication that may arise despite preventative measures. To check for hypocalcemia, ionised calcium and parathyroid hormone levels (responsible for regulating the body's calcium) are checked. If needed, oral calcium may be provided, while in more severe cases, a calcium IV will be administered.³ 

Those who have undergone a total thyroidectomy are normally discharged with oral calcium tablets. Additionally, as the whole thyroid has been removed, the body will no longer be able to produce its thyroid hormones. As a result, patients are prescribed levothyroxine, which must be taken for life to maintain normal/target range thyroid hormone levels. Those who have had a hemithyroidectomy may also be placed on a small dose of levothyroxine if hypothyroidism (an underactive thyroid) is developed. However, this has only been shown to occur in approximately 10-15% of patients.^3,5 

After surgery, it may take two to three weeks to recover, however, this does vary depending on your body.⁷ During the recovery process, follow-up appointments are also required. Follow-ups last for approximately six to eight weeks after surgery, where blood tests are taken to look over thyroid function and calcium levels.⁵ 

Conclusion

To conclude, thyroidectomy is an effective treatment option for thyrotoxicosis, especially in cases where medication has not been able to reduce thyroid hormone levels. The type of thyroidectomy conducted, whether it is a total thyroidectomy, near-total thyroidectomy, or hemithyroidectomy, depends on the severity of the condition and the patient’s condition. Preoperative evaluations, such as blood tests to determine hormone levels as well as X-rays, are essential to ensure that the patient is fit for surgery and to minimise potential risks. 

The surgery itself is quite complex due to the thyroid gland’s location and anatomical structure. The outcomes of the surgery are quite successful; however,  some complications may occur, such as hypocalcemia, which is managed by calcium supplements. Furthermore, follow-up care helps to monitor the patient's recovery and address any potential complications as soon as they develop.

Overall, thyroidectomy offers a favourable long-term prognosis for patients with thyrotoxicosis, improving symptoms and quality of life; however, some individuals may require continuous thyroid hormone replacement therapy. Recent advancements have also sought to minimise the invasive nature of the procedure, lowering the risk of complications.⁸