What is Thyroidectomy?
Anatomy and Physiology
The thyroid gland is a structure that sits in the midline of the neck. It comprises of two lobes (left and right) joined by an isthmus. The gland produces a hormone that is integral in maintaining the body’s metabolic status amongst other things. The gland is supplied by at least 2 major arteries on either side and approximately 3 major veins on either side. Intimate to the thyroid gland is the trachea (windpipe), oesophagus (swallowing tube) and most importantly from an operative perspective the recurrent laryngeal nerve on both sides that supply the voice box musculature and are integral to voice production. In addition there are approximately 4 parathyroid gland associated with the thyroid gland that are important with the maintenance of calcium metabolism.
Indications for thyroidectomy
There are a number of indications to consider removal of the thyroid gland:
- Malignancy or risk of malignancy (cancer)
- Pressure symptoms related to the thyroid gland on the airway or the oesophagus
- Uncontrolled thyrotoxicosis (overactivity of the thyroid gland) with medical treatment.
It is important to investigate any lump or mass in the thyroid gland that sits in the midline of the neck. This typically is undertaken using an Ultrasound scan. It is not uncommon especially if there is a solitary lump in the thyroid gland for this to be further investigated using a fine needle aspirate cytology (FNAC).This involves a needle directed into the nodule and a few cells withdrawn from it which are then looked at microscopically. This often can be helpful but is dependant upon the person undertaking the FNAC and then the person who examines the cells microscopically.
A number of operations are mentioned in the literature and can be confusing for the patient. In the present day most people are practicing the following operations.
Total thyroidectomy – Removing all of the thyroid tissue
Hemithyroidectomy – Removing one lobe of the thyroid and the isthmus.
Isthmusectomy – Removal of the section of thyroid that joins the two lobes (uncommonly used)
Surgery is undertaken using a general anaesthetic and a low neck incision is made. The thyroid gland is mobilized and Mr Vaz is trained in traditional techniques and the use of the harmonic scalpel to do this. The upper pole of the thyroid and the major vessels are divided and the recurrent laryngeal nerve is identified followed and preserved. If only a hemithyroidectomy is performed then the free lobe is separated from the isthmus and then sent for histology (microscopic examination).
Every patient will have a scar that typically is quite well hidden in the neck given time and only occasionally does this scar become prominent.
There is a risk to the recurrent laryngeal nerve and if this is damaged on one side then the voice becomes hoarse. If damaged on both sides then the vocal cords become immobile and can pose difficulties with breathing.
All operations carry the risk of bleeding and infection but thankfully this is low with thyroidectomy.
Occasionally with total thyroidectomy the calcium level may fall due to the removal of the above mentioned parathyroid glands. This may require long term replacement with Calcium.
With a total thyroidectomy the patient will be rendered hypothyroid (underfunctioning thyroid) and will require supplementation with thyroxine.
Most patients will require a drain in the neck postoperatively and this will be removed when the drainage is minimal. After this the patient may go home with some simple pain relief.