Mr Crinnion is a specialist in endocrine surgery. He treats patients with thyroid and parathyroid conditions.

Please click below for more details on endocrine surgery provided by Mr Crinnion.


Thyroid Surgery

What is the Thyroid Gland


The Thyroid gland lies in the front of the neck and produces a very important hormone called thyroxine, which regulates the metabolism of the body.  There are many diseases that can affect the size and function of the thyroid gland. An enlargement or swelling of the thyroid gland is known as a goitre.



Reduced production of thyroid hormone (myxoedma)

It is quite common for the thyroid gland to become underactive and produce insufficient thyroxine. This may lead to tiredness, depression, weight gain and constipation. This condition is known as myxedema and can be easily diagnosed with a blood test. The condition can be simply reversed by taking a daily supplement of naturally occurring thyroid hormone.

Increased production of thyroid hormone (thyrotoxicosis, Grave's Disease)

The thyroid gland may become overactive with the uncontrolled production and release of thyroxine. This will result in restlessness, increased appetite, weight loss, difficulty in sleeping, feeling hot and sweaty and sometimes palpatations.

Thyrotoxicosis is diagnosed by a blood sample and is treated initially with tablets which block the production and release of the excessive thyroid hormone. A patient who is diagnosed with thyrotoxicosis should be referred to an endocrinologist, who will prescribe medication, and monitor the progress of the condition. In some patients the over-activity of the thyroid will settle naturally in time, but in many the condition will persist.#

If thyrotoxicosis fails to settle, then an endocrinologist will usually recommend a permanent cure for the condition. This will either be an operation to remove the thyroid gland, or treatment with radioiodine which destroys the thyroid tissue. The endocrinologist will explain and discuss the most appropriate treatment. If an operation is recommended then the endocrinologist will refer the patient to an appropriate specialist thyroid surgeon.

Thyroid enlargment or Swelling (goitre)

The thyroid gland is located in the central area of the lower neck in front of the trachea or wind-pipe. It is made up of two lobes (right and left) that sit either side of the trachea. These are joined together by a part of the gland known as the isthmus which sits in front of the trachea. A normal thyroid gland cannot usually be easily seen or felt. Sometimes the thyroid gland can become enlarged producing a visible lump in the neck. Enlargement or swelling of the thyroid gland is in most instances entirely benign, but it does need to be investigated by either an endocrinologist, or specialist thyroid surgeon.

How is a lump in the thyroid investigated?

If a patient notices a lump in the neck then this must be reported to the General practitioner (GP).

In most instances the GP will diagnose the lump as a thyroid swelling and refer to an appropriate specialist. Occasionally the GP will organise an ultrasound examination to confirm that the swelling is within the thyroid gland. A blood test will also be requested to assess whether the thyroid gland is functioning normally.

On seeing a specialist, the neck will be examined, and usually an ultrasound will be arranged. Sometimes, a needle biopsy of the swelling will be organised. This procedure is also known as fine needle aspiration cytology. It is extremely safe and will cause minimal discomfort. The purpose of the biopsy is to diagnose the cause of the thyroid swelling. The thyroid specialist may also arrange further blood tests. The results of all of these tests will enable an accurate diagnosis to be made.

Possible Diagnosis

Most swellings within the thyroid gland are benign, and no further action is necessary unless there is cosmetic concern, or the lump causes symptoms due to pressure on the trachea (wind-pipe) or oesophagus (swallowing tube).

Sometimes the needle biopsy may either diagnose a tumour, or suggest the possibility of a tumour. In this situation the specialist will recommend that the swelling is removed to obtain a definite diagnosis. This operation is known as a thyroidectomy. It is very important to understand that tumours or growths within the thyroid gland almost always run a very benign course, and prompt surgical removal and further non-invasive treatment achieve a permanent cure.

Thyroid Surgery (thyroidectomy)

A thyroidectomy is the surgical removal of half or all of the thyroid gland.

Operations are necessary in the following situations:

  • To remove swellings that may be malignant
  • To treat thyrotoxicosis      
  • To remove very large thyroid glands that are exerting pressure on the oesophagus or trachea

The operation on the thyroid is carried out through a curved horizontal incision in the lower central portion of the neck. The surgeon will either remove one half of the thyroid or the whole of the thyroid gland. At the end of the operation the incision is closed with a stitch and a small tube is usually left in the wound for 24 hr to drain any tissue fluid. The total hospital stay will usually be 1 or 2 nights.

Complications of Surgery

Following the operation there will be some local swelling, a sore throat and often some discomfort whilst swallowing. These symptoms are usually transient and disappear spontaneously.

For the first few weeks or months there will be some swelling under the scar. However, this will settle and after a few months most scars are barely visible. Rarely,
some undue thickening (keloid) of the scar can occur which is more common in patients of oriental or black origin. In such cases the scar may take a couple of years to mature. 

Voice Changes

The nerves controlling the vocal cords lie very close to the thyroid gland and great care is taken during surgery to avoid injury to these nerves. Sometimes there is some impairment of the voice after surgery (hoarseness, difficulty in projecting the voice). These changes are usually temporary and resolve completely.  There is about a 1% chance of damage to the nerves that control the vocal cords that can lead to permanent weakness of the voice. However, significant difficulty with everyday speech is extremely rare.

Parathyroid glands

These are four tiny glands next to your thyroid, which control blood calcium. When the whole thyroid gland has been removed a reduction in blood calcium may follow, which is usually temporary. Following your operation blood will be taken to measure the calcium level. If this falls then calcium supplements will be given. Rarely, after discharge from hospital the calcium may continue to fall to a low level and you may experience tingling around the mouth and in the fingers and toes.  These symptoms will settle when calcium supplements are given. Calcium supplements may be required for a few weeks until the parathyroid glands recover from the trauma of the operation. It is unusual to require permanent calcium supplements.

Thyroid Replacement

It the whole of the thyroid gland is removed then you will require the daily replacement of thyroid hormone (thyroxine). Initially you will require regular blood tests to establish the correct dose of thyroxine to maintain your normal rate of metabolism. 

Post-operative Care

Depending on your recovery you can expect a TOTAL HOSPITAL STAY OF 1-3 NIGHTS. You will be able to eat and drink normally when you have recovered from the anaesthetic. If you have a drain in place this will be removed before you are discharged.

Going Home
  • A single suture under the skin will be removed after 5 days.
  • The wound is not normally painful and any discomfort usually settles in a few days. You will be given a supply of suitable painkillers before you are discharged home which you may take as required.
  • Your wound will be covered with a waterproof dressing and you may shower normally. Advice will be given about wound care at the time of discharge.
  • You can return to work when your wound is sufficiently comfortable, this is usually after 1-2 weeks
  • Before you drive any vehicle check with your insurance company how soon you can drive as you may find you are not covered for a certain time after surgery.



Parathyroid Surgery

Parathyroid glands

These comprise four small structures that normally measure about 5mm in diameter and weigh only 30-50 mg. There are two glands on either side of the neck and they are located behind the much larger thyroid gland.

Normal Function

The parathyroid glands release a hormone called parathyroid hormone (PTH) which maintains a normal blood level of calcium.  Optimal levels of calcium are vital for the normal function of the nervous system and skeletal muscles.  Adequate calcium is also required for normal blood clotting.

How does PTH maintain a normal calcium level?

When the blood calcium level falls it is immediately recognised by the parathyroid glands, and this triggers the release of PTH. PTH acts on bones to release calcium from the bone matrix. It also acts on the kidneys to reduce the loss of calcium in the urine, and acts on the gut to absorb more calcium in the diet. These effects raise the blood calcium level back to normal. When the blood calcium level is within the normal range it is detected by the parathyroid glands and the release of PTH is reduced. By this mechanism the blood calcium level is maintained at a level to allow normal nerve and muscle function.

Diseases of the parathyroid glands

Increased parathyroid gland activity

This is called primary hyperparathyroidism (pHPT) and is one of the most common disorders of the endocrine glands. The incidence of this condition increases with age and is more common in elderly women.

What is the cause of pHPT

  1. Parathyroid adenoma: pHPT is most commonly caused by an increase in size and activity of one of the parathyroid glands. This enlarged gland is known as a parathyroid adenoma. The adenoma does not recognise or respond to the blood calcium level and constantly releases high levels of PTH. Often a parathyroid adenoma will be 20 times as large as a normal gland.  In a few patients more than 1 parathyroid adenoma may be present.

  2. Parathyroid hyperplasia: In this condition several of the parathyroid glands increase in size and together release large amounts of PTH.

  3. Parathyroid Malignancy: Rarely one of the parathyroid glands enlarges and invades into the adjacent tissues. This occurs in less than 1% of cases of  pHPT.

What are the effects of pHPT?

  1. An increase in the blood level of calcium. If the calcium rises to very high levels the patient will complain of excessive thirst and pass large amounts of urine. Dangerously high levels of blood calcium may occur but this is unusual.
  2. The high level of PTH will lead to increased release of calcium from the bones  resulting in thinning of the bones (osteoporosis) and an increased risk of fractures. In severe cases bone pain will be present.
  3. A high level of calcium within the urine can cause kidney stones.
  4. High blood pressure and stomach ulcers are increased in patients suffering with pHPT.
  5. Some patients with pHPT feel tired, depressed and lack energy. These symptoms are frequently helped if the condition is cured.

 How is pHPTdiagnosed?

  1. Most patients will be diagnosed following routine blood tests.
  2. It is often detected in patients who are diagnosed with kidney stones.
  3. It is frequently diagnosed in patients investigated for osteoporosis.

How is pHPT investigated?

  1. A bone scan will be performed to assess whether there is any damage to the skeleton. This will determine the risk of future fractures.
  2. A 24hr collection of urine may be taken to measure the quantity of calcium excreted in the urine.
  3. A ultrasound examination of the neck will be performed to look for enlarged parathyroid glands.
  4. A radio-nucleotide scan of the neck known as a Sestimibi scan will be arranged to identify the site of any parathyroid glands showing increased activity

When and how is pHPT treated?

Conservative treatment

Mild cases of pHPT with only marginal elevation of the blood calcium levels and no damage to the skeleton may be managed by clinic follow-up and regular blood tests. Most patients will be under the care of an endocrinologist. If the calcium level rises or complications develop then the patient will be referred for surgery.


Patients who have a high calcium level, kidney stones, osteoporosis or symptoms such as lethargy and depression will be referred for surgical treatment.

Surgical Procedures

The surgical procedure to remove abnormal parathyroid glands is called a parathyroidectomy. The nature of the operation recommended by the specialist surgeon will depend upon the results of the ultrasound and radio-nucleotide scans.

Minimal Incision or minimal access parathyroidectomy

This procedure can be performed if the scans of the neck can accurately identify the site of the single abnormal gland. This operation is performed via a small incision on the side of the neck and the abnormal gland is excised. It is a very low risk simple procedure. Around 70% of patients with pHPT are suitable for this approach.

Parathyroid Exploration

In patients with negative scans a collar incision across the lower neck is necessary. In this procedure the surgeon will carefully search for any abnormal glands which will be removed. This is not a major procedure and the wound will heal nicely with minimal scarring.

Results of Surgery

About 95% of patients with pHPT will be cured with parathyroid surgery. Occasionally an operation will fail and the reasons why this may occur will be explained by your surgeon. Serious complications following parathyroid surgery are extremely rare in the hands of an experienced thyroid and parathyroid surgeon.