20 November 2017
The thyroid gland lies in front of the lower neck and is butterfly shaped organ with a left and right half. The gland uses iodine (found in small quantities of many foods), to produce thyroid hormone which circulates in the bloodstream. Thyroid hormone is like the fuel for our body and regulates our body's basal metabolic rate which in turn, affects the function of many systems in the body (e.g. appetite, weight, heart rate, bowel function, hair loss, mood etc). Thyroid hormones are therefore essential for survival.
What can go wrong with the thyroid?
There are fundamentally two ways that the thyroid gland can be affected:
- Medical thyroid disease - where the thyroid gland is either over or under active, resulting in hyperthyroidism or hypothyroidism. Both these conditions can be diagnosed with a simple blood test to check thyroid function levels. Hyperthyroidism and hypothyroidism can both be treated with medication to correct and control thyroid function back to a normal range. In some cases, surgery in the form of total thyroidectomy maybe considered as a definitive treatment for hyperthyroidism.
- Goitre - where there is enlargement of the thyroid gland. If the whole gland is diffusely enlarged it is called a diffuse goitre. If there is a single nodule, it is termed a solitary nodule. Nodular goitres are very common and are most commonly benign. However, a small proportion of goitres maybe malignant and therefore patients with newly identified thyroid swellings, warrant further initial investigations.
A detailed history is taken to determine any recent change in size with respect to the thyroid swelling and to identify if any symptoms resulting in compression are present; large goitres may sometimes affect breathing, swallowing and voice. A neck examination may identify the presence of nodules. It will also evaluate the position of the trachea which can sometimes be shifted by the pressure of large nodules or goitres, and elicit if there is any extension behind the breastbone, as very large goitres can sometimes enlarge downwards into the chest cavity. The examination is completed with laryngeal examination, using flexible nasal endoscopy, to determine vocal cord function. This can be done as an outpatient procedure, during the initial consultation, using simple topical local anaesthetic spray.
Investigation and treatment of thyroid lump
Any new thyroid swelling should be investigated with an ultrasound scan of the neck; this should be performed by an expert head and neck radiologist, who will be able to report on the nature of the thyroid swelling. During the ultrasound scan, FNAC (fine needle aspiration for cytology) maybe performed, where a needle is inserted into the swelling to collect a sample of cells, for analysis. The cytology result will be reported and grading as per the national Thy classification, and the results discussed with the patient. In any suspicious cases where there are concerns of underlying malignancy, the results of all the investigations will be discussed in our local Thyroid Multidisciplinary meeting.
In select cases, other additional investigations maybe necessary, such as a CT scan or nuclear isotope scan.
Often no treatment may be necessary for a goitre, particularly if there aren't any symptoms resulting in compression and no concerns of underlying malignancy. In such cases a surveillance approach with a ‘watch and wait policy’ maybe advised. Alternatively, thyroid surgery may be considered if there are any suspicions of cancer, pressure symptoms, uncontrolled over activity, or cosmetic concerns.
Thyroid surgery either involves removing half of the gland (hemi-thyroidectomy or lobectomy), or the whole gland (total thyroidectomy).
Thyroid surgery is classed as a major operation, performed under a general anaesthetic, with an average inpatient stay of one to two days.
Risks involved in thyroidectomy
Aside from general risks associated with any operation (general anaesthetic, bleeding, infection), there are some specific risks pertinent to thyroid surgery. The first is the small risk to the recurrent laryngeal nerve and superior laryngeal nerve, which are both in close proximity to the thyroid gland. If bruised, this may result in a change in the speaking and / or singing voice, but this usually recovers. Very rarely, there maybe permanent injury which would affect the voice long term.
Parathyroid – calcium problems
This is only applicable following total thyroidectomy. The tiny parathyroid glands which regulate circulating calcium levels, lie very close to the thyroid gland. If affected, the calcium levels may fall after surgery, which may manifest as symptoms of tingling or numbness in the hands, fingers, toes and lips.
The calcium levels in the blood are therefore monitored after total thyroidectomy, and replaced with calcium supplements as necessary, either temporarily or sometimes long term.
What else should I know regarding thyroid surgery?
After total thyroidectomy, all patients will need to take replacement thyroid hormones in the form of levothyroxine medication, daily for life. However, if only hemithyroidectomy is needed, then generally thyroid hormone replacement is not required. The remaining half of the thyroid gland that is left behind is almost always sufficient to produce enough thyroid hormones to meet the body's demands.
If you have thyroid concerns, you may wish to book a consultation with Miss Natasha Choudhury, Consultant ENT Surgeon at Gatwick Park Hospital. Miss Choudhury is also the lead Thyroid and Parathyroid surgeon at Surrey & Sussex NHS Trust, and is the local Chair of the Thyroid Network Multidisciplinary meeting.