WHERE IS THE THYROID GLAND, AND WHAT DOES IT DO?
The thyroid gland is a butterfly-shaped gland that sits in the front of the neck. It produces two main hormones: thyroxine (T4) and tri-iodothyronine (T3). These hormones perform many functions, and help to regulate your body’s metabolism, temperature, weight, heart rate and neurological function. There are 2 lobes, right and left, joined to each other in the middle by the ‘isthmus’.
WHAT IS A THYROID NODULE?
Thyroid nodules are solid or fluid-filled lumps that form within the thyroid. The cause is usually unknown but can sometimes be hereditary or associated with other thyroid conditions including Hashimoto’s thyroiditis or rarely from iodine deficiency. Most thyroid nodules occur from overgrowth of normal thyroid tissue and are benign and harmless. Thyroid nodules usually do not cause symptoms, but can sometimes grow and press on other structures in the neck and cause trouble with breathing, swallowing, choking or voice changes. Other problems include growth of the thyroid into the chest cavity (‘retrosternal extension’) and overactive or ‘toxic’ nodules. Only a small percentage of thyroid nodules are cancerous.
WHEN SHOULD A THYROID NODULE BE BIOPSIED?
The decision to recommend biopsy of a nodule is based on many factors including family history, the size and growth pattern of the nodule, and the appearance of the nodule on ultrasound.
WHAT ARE THE POSSIBLE RESULTS OF A THYROID BIOPSY?
The results of a thyroid fine needle biopsy is classified into 6 categories, based on the Bethesda classification system. Bethesda 1 result means insufficient material and usually will require a repeat biopsy. Bethesda 2 result indicates a benign nodule. Bethesda 3 and 4 are atypical categories which are still usually benign nodules however may require surgical removal to rule out cancer. Bethesda 5 and 6 results usually indicate a cancerous nodule.
WHAT ARE THE SIGNS OF AN OVERACTIVE THYROID, AND WHAT ARE THE CAUSES?
Hyperthyroidism is a health condition that occurs when the thyroid gland becomes overactive and produces more thyroid hormone than you need. The signs may include tremors, sweats, palpitations, heat intolerance, nervousness, irritability, weight loss, diarrhoea, menstrual irregularities, and an enlarged thyroid gland (goitre). Causes of hyperthyroidism include Grave’s disease, toxic multinodular goitre, toxic adenoma, thyroiditis and certain medications. Bulging and swollen eyes can occur specifically with Grave’s disease.
WHAT WILL HAPPEN DURING MY CONSULTATION FOR A THYROID PROBLEM?
Your consultation will begin with a careful history and physical examination, followed by review of your results including blood tests and scans. A bedside office ultrasound will be conducted to provide real-time diagnostic information. A nasendoscopy (thin fibre-optic camera procedure via the nostril) may be performed under local anaesthesia to examine the function of your vocal cords. Further investigations including additional scans and biopsies may be recommended. Treatment options will then be discussed and you will have the opportunity to ask questions in order to make the best decisions for your care.
DO PATIENTS WITH THYROID CANCER HAVE ACCESS TO OTHER HOSPITAL RESOURCES?
We participate in the joint Liverpool and Campbelltown Endocrine Surgical multidisciplinary team (MDT) meeting, in which a panel of thyroid cancer experts from different specialities review all cases of patients who have been diagnosed with thyroid cancer, and also continue to provide recommendations over the long term follow up. Our participation with this MDT is a key component of best practice and high quality of care when looking after patients with thyroid cancer.
WHEN IS THYROID SURGERY RECOMMENDED?
Thyroid surgery might be recommended for some of the following reasons
Malignant nodule (thyroid cancer)
Nodules that are atypical on biopsy (Bethesda 3 and 4) in order to rule out a cancer,
Enlarged multinodular goiter causing pressure symptoms or cosmetic disturbance
Hyperthyroidism conditions that are not suitable for, or have failed, medical or other therapies – including Grave’s disease, toxic multinodular goiter, toxic adenoma
Extension and growth of the thyroid into the chest (retrosternal extension)
HOW IS THYROID SURGERY PERFORMED?
Thyroidectomy is performed under general anaesthesia, so you won’t be conscious during the procedure. An incision will be made low in the centre of your neck, and sometimes be placed in a skin crease to ‘hide’ the scar. All or part of the thyroid gland is then removed depending on the reason for the surgery. If you’re having a thyroidectomy for cancer, you might also have some of the lymph nodes removed around your thyroid (central neck dissection) or on the side of the neck (lateral neck dissection). Thyroidectomy usually takes 1 to 2 hours, but can take longer. Intraoperative nerve monitoring (IONM) is used during the procedure to help identify and protect the important recurrent laryngeal nerves that are in close proximity to the thyroid gland.
Transoral thyroidectomy is a recently developed procedure where the thyroid gland is removed through incisions in the mouth, therefore avoiding a neck incision, although is not suitable for many patients. This technique is currently under development at the Sydney Surgical Clinic.
ARE THERE POSSIBLE COMPLICATIONS OF THYROID SURGERY?
Like any operation, thyroidectomy has some risks although most patients do not have significant problems post-surgery. Possible complications include risks of general anaesthesia (e.g cardiac or respiratory problems), bleeding, infection, voice change, hypoparathyroidism and recurrent laryngeal nerve problems. If having a total thyroidectomy, lifelong thyroxine supplementation will be required. Hemithyroidectomy (only removing one lobe of the thyroid) does not usually result in thyroxine medication dependence, but might do in 5-10% of patients.
Hypoparathyroidism – the parathyroid glands are tiny glands that are closely related to the thyroid gland but perform a completely different function. Parathyroid glands regulate the body’s calcium level. In some patients undergoing thyroidectomy, the parathyroid glands show reduced function after the surgery, which can lead to low blood calcium concentration. This is usually only an issue for patients undergoing a total thyroidectomy. We check parathyroid hormone levels immediately after completion of thyroidectomy, and if reduced function is identified, calcium supplements will be prescribed. This is usually temporary and most patients only require supplements for 1-2 weeks until return of parathyroid function. We usually quote a 10-15% risk of temporary hypoparathyroidism, and <1% risk of permanent hypoparathyroidism. We are proud to have a track record of low rates of hypoparathyroidism for our patients, which is considered a marker of surgical quality.
Recurrent laryngeal nerves – these nerves control the vocal cords, and run in very close proximity to the thyroid gland. There is a 5% risk of a temporary loss of function of one of the recurrent nerves due to exposure and pulling on the nerve as the thyroid gland is removed. The usual symptoms include voice hoarseness and occasionally swallowing problems, but some patients do not notice symptoms. Usually function will return spontaneously in days to weeks. The risk of a permanent nerve palsy is less than 1%. We use intraoperative nerve monitoring to help identify and protect the recurrent laryngeal nerves during thyroidectomy, and also wear high-magnification loupes which aids both nerve and parathyroid gland identification. Some patients may experience post-operative voice changes even with both recurrent nerves working normally, and these are usually temporary.
Having your operation performed by a high-volume surgeon who specialises in thyroid surgery is the best way to minimise the risk of complications and achieve the best surgical outcome.
WHAT IS THE RECOVERY LIKE AFTER THYROID SURGERY?
Recovery after thyroid surgery is usually straightforward. Most patients have minimal pain, eat and drink normally and return to work within 7-10 days. Light duties are preferable for two weeks after surgery. Further advice regarding recovery in your specific circumstances will be discussed during the preoperative consultation.
HOW WILL I FEEL WITHOUT A THYROID, AND WILL I PUT ON WEIGHT AFTER THYROIDECTOMY?
Many patients worry about life without a thyroid gland, but the majority of patients will notice no difference in day to day life, provided a daily thyroxine supplement is taken as instructed. There is no good quality evidence that thyroidectomy leads to weight gain, and published studies have showed widely differing results. A recent Monash University study showed that 1/3 of patients gained weight, 1/3 stayed the same and 1/3 of patients lost weight with an average gain/loss of 6%, and could not therefore demonstrate a clear link between thyroidectomy and weight gain.