Thyroid for Dummies (27 page)

If you are about to have surgery, you need to know a few things to make the experience as benign as possible. Revealing those things is the purpose of this chapter. Although you won’t be an expert on thyroid surgery after reading this information (at least not after your first reading), you will get a good idea of what to expect, so that you won’t get any surprises.

Deciding When Surgery Is Necessary

John is a 45-year-old man who has a solitary thyroid nodule – a lump on the thyroid. His GP checks his thyroid function tests, which come back normal, and immediately refers John to the thyroid specialist clinic. The consultant endocrinologist (hormone expert) performs a fine needle biopsy, which 19_031727 ch13.qxp 9/6/06 10:46 PM Page 148

148
Part III: Managing Your Thyroid

shows a follicular lesion – tissue that looks like normal thyroid follicles (the circles of cells that make thyroid hormone). The pathologist is uncertain whether the nodule is cancerous or not. The consultant arranges for John to see a thyroid surgeon with extensive experience, to discuss thyroid surgery.

After examining John, the surgeon tells him that he needs a lobectomy (the removal of one lobe of the thyroid). During the operation, a pathologist will examine the tissue that is removed to give a definitive diagnosis. If the lobectomy shows that John has follicular cancer, the surgeon plans to remove the whole thyroid gland (total thyroidectomy). If the tissue is benign, the surgeon plans to leave the remaining lobe intact.

John doesn’t eat on the morning of surgery. The operation is supposed to start at 9a.m., but due to various glitches, it doesn’t begin until 11a.m. He is given a general anaesthetic and the operation goes smoothly. The pathologist examines the excised thyroid tissue under a microscope and diagnoses a follicular carcinoma (cancer) so the surgeon proceeds to a total thyroidectomy.

The surgeon cannot feel enlarged lymph nodes on the side of the thyroid, but removes nodes in the central neck to look for cancer there. The pathologist determines that these nodes are not cancerous.

After the surgery, John feels some soreness in his neck but is not hoarse. The incision on his neck is covered with a clear plastic bandage. John has a chest X-ray and bone scan to make certain that cancer hasn’t spread to those areas.

These tests come back negative, indicating no cancer spread.

Several weeks after surgery, John receives a dose of radioactive iodine (refer to Chapter 6) to destroy any remaining thyroid tissue. For the next several years, John sees his doctor about every six months. The doctor finds no indications that the cancer is recurring.

A number of reasons might bring you to the thyroid surgeon. John’s situation is one of the most serious – thyroid cancer (check out Chapter 8 for more on the types and treatment of thyroid cancer). But several other thyroid situations are best handled with surgery as well.

If you are hyperthyroid and antithyroid pills don’t successfully treat your condition (or if you’re allergic to them), and you don’t want to have treatment with radioactive iodine, surgery is your only other choice. If you’re pregnant and develop hyperthyroidism, and you’re unable to take the antithyroid pills because of allergies, surgery is your only option. (You cannot receive radioactive iodine during pregnancy as this treatment harms your baby’s thyroid tissue, too.)

If you have a large thyroid that’s causing local symptoms in your neck, such as trouble swallowing or breathing, or if the goitre is especially unattractive, surgery is necessary, although radioactive iodine is another option in these situations.

19_031727 ch13.qxp 9/6/06 10:46 PM Page 149

Chapter 13: Going In: Surgery on the Thyroid Gland
149

Talking Things Over

National guidelines from the British Thyroid Association and the Royal College of Physicians of London recommend that, if you have symptoms that might be due to thyroid cancer, your doctor refers you to a thyroid specialist clinic. This clinic is run by a team that includes an experienced thyroid surgeon, as well as a thyroid or endocrine physician, pathologist, oncologist (cancer specialist) and a nuclear medicine expert, as well as highly trained nurses. The clinic aims to see you as soon as possible and, if you have a thyroid lump, you’re usually seen within two weeks of referral.

When you need surgery, the thyroid specialist clinic understands that you have a lot of important questions that need to be fully discussed before going ahead with surgery. Trained nurses are available in the clinic for you to talk to, and you’re also given written information about your condition and its treatment. This information is especially important if you are diagnosed with thyroid cancer. In this case, the guidelines also allow you the opportunity for another appointment for further explanations and discussion, as you may find difficulty taking in all the information you’re given at a single consultation. When your diagnosis is cancer, the clinic also aims to inform your GP

within 24 hours (by telephone or fax) so that she is aware of the situation, and your planned treatment.

If at any time you have questions about your thyroid condition, the operation you need, or your treatment (whether current or future) always ask.

Preparing for Surgery

If you’re having an operation for hyperthyroidism, you’ll probably take antithyroid pills for four to six weeks before surgery to get your thyroid function as normal as possible according to a free T4 test. (If you can’t take antithyroid pills because of an allergy, obviously you skip this step.) You may also need iodine for 10 days before surgery to reduce the size of the thyroid and the blood vessels supplying it. If you have symptoms such as a rapid heartbeat or shakiness, you can control them with propranolol; a type of drug called a beta-blocker that damps down overactivity in part of your nervous system.

If you have hypothyroidism, you need to take thyroid hormone replacement pills before surgery so that your thyroid function is normal. Anaesthesia is risky if the patient is very hypothyroid.

19_031727 ch13.qxp 9/6/06 10:46 PM Page 150

150
Part III: Managing Your Thyroid

If you’re taking aspirin or other medications like warfarin to thin your blood (and therefore prolong bleeding), you also need to stop taking these a week before surgery. Ask your doctor or surgeon for advice about what to do if they haven’t already mentioned this important fact. A few days prior to surgery, you also have blood tests to confirm that your liver and kidneys are perform-ing satisfactorily. The doctor also wants to check that you do not have anaemia (deficiency of red cells or of haemoglobin in your blood), although you won’t lose much blood during thyroid surgery.

You should eat nothing after supper the night before surgery. The anxiety, the trauma of surgery, and the anaesthesia all make you more prone to vomit, and you don’t want to have anything in your stomach should this happen.

You generally come to the hospital on the morning of surgery. You are wheeled into the operating room, where the anaesthetist gives you a general anaesthetic. (Sometimes you are given a local anaesthetic instead, but this action is unusual.) Two hours later, you wake up minus some of or all your thyroid.

(Be aware though that it’s not an efficient way to lose weight – unless you have a particularly large goitre.)

What Happens During Surgery

After all the preparations of cleaning and covering the area of the operation, the surgeon makes an incision about 7 to 8 centimetres long horizontally over your thyroid gland. The surgeon carefully places the incision over a normal skin crease (where your skin folds as you bend your head forward) and makes the smallest incision possible to minimise the scar. If the surgeon has to remove lymph nodes, the incision is carried up in the direction of the ear at one or both ends of the incision. The incision cuts through the fat under-neath the skin and a thin layer of muscle called the platysma. The skin and the muscle overlying the thyroid are pulled back to reveal the thyroid gland.

The surgeon then sees what he or she needs to deal with in the next hour or so. The thyroid is shaped like a butterfly, with an isthmus (narrow strip) of thyroid tissue connecting the two ‘wings’ of the butterfly. Above the isthmus, the surgeon may see a projection of thyroid tissue called the pyramidal lobe.

This lobe is usually removed during any partial thyroid operation so that it doesn’t regrow as a large bump on the front of the neck when the remaining gland enlarges to restore thyroid hormone production.

The surgeon knows that the thyroid is firmly fixed to the trachea (air passage) and larynx (voice box) at the back, so any operation involves freeing up the thyroid before the surgeon removes the thyroid tissue. The surgeon sees two 19_031727 ch13.qxp 9/6/06 10:46 PM Page 151

Chapter 13: Going In: Surgery on the Thyroid Gland
151

superior thyroid arteries entering the thyroid from above and two inferior thyroid arteries entering the thyroid from below. A fifth artery sometimes enters the thyroid in its central portion from below. These arteries are sometimes tied and cut depending upon how much of the thyroid is removed.

The surgeon must also deal with the thyroid veins. The middle thyroid veins connect to the thyroid from the side. These veins are tied and cut. The veins connecting to the top of the thyroid, called the superior thyroid veins, are also tied and cut if the plan is to remove the entire lobe.

Between three and six parathyroid glands, as well as the recurrent laryngeal nerves (one on each side), are found on the back of the thyroid and are carefully preserved if possible. (See ‘Surgical obstacles’, the next section, for details.)

Studies show that if a dye is injected into the thyroid, the dye goes to the chain of lymph nodes on the trachea behind the isthmus. The surgeon knows that this chain is where to look first for the spread of cancer.

At this point, the purpose of the surgery determines what’s done next. If the operation is to remove a hot nodule (refer to Chapter 7), the surgeon locates any blood supply to it, cuts and ties off the blood supply, and removes the nodule. If hyperthyroidism is the reason for surgery, the surgeon performs a subtotal thyroidectomy, leaving a few grams of the part of the thyroid near-est the trachea to avoid damaging the parathyroid glands. If surgery is for thyroid cancer, the procedure is dependent on the type and spread of the disease. (For more information, refer to Chapter 8 and also see the section

‘Extent of surgery’ later on in this chapter.)

Surgical obstacles

In any thyroid surgery, the main obstacles to easy surgery are the parathyroid glands and the recurrent laryngeal nerves.

Parathyroid glands

The parathyroid glands sit on the back of the thyroid and share blood supply with it. Usually, you have four of these tiny glands, but sometimes you have more or less, and to make things interesting for the surgeon, they are found in many locations.

The parathyroids are responsible for managing the calcium level in your blood. If they aren’t functioning, your calcium level falls. Someone whose parathyroids are not functioning may experience tingling in her lips and 19_031727 ch13.qxp 9/6/06 10:46 PM Page 152

152
Part III: Managing Your Thyroid

numbness in her hands or feet, or even severe muscle spasms. Sometimes, the trauma of surgery causes the parathyroids to shut off temporarily, but they recover in a few days.

With a total thyroidectomy, preserving the parathyroid glands is often not possible. In that case, they are cut into small pieces and injected back into a muscle, for example in the shoulder, where they seem to function just fine.

If a person has symptoms of low calcium after surgery, the problem is usually managed with oral calcium supplements. Rarely, intravenous calcium is needed. If, through chance, the parathyroids fail to recover their function after surgery, the patient takes vitamin D and calcium for the rest of their life. This is a rare occurrence associated with only 1 in 300 surgeries of the thyroid.

Recurrent laryngeal nerves

The recurrent laryngeal nerves on both sides of the thyroid are major obstacles to the surgeon. Each nerve controls the vocal cord on its side. Both nerves lie close to the thyroid and are easily cut accidentally or included in a knot that is tying off a blood vessel. If the diagnosis is thyroid cancer, one or both of the recurrent laryngeal nerves may already be cancerous, and are therefore sacrificed at the time of surgery.

Sometimes, the recurrent laryngeal nerves are temporarily damaged or bruised during surgery. If so, the person has a hoarse voice for a few days after the operation. If both nerves are damaged, the situation is more serious, and a tracheostomy is often needed so that the patient can breathe. The damage and the hoarseness can remain as a permanent side effect of the surgery.

Damage to a recurrent laryngeal nerve is normally rare. In good hands, damage doesn’t occur more often than once for every 250 operations on the thyroid, as the surgeon is careful to look for, and preserve these important structures.

The superior laryngeal nerve is sometimes injured during surgery as well.

Damage to this nerve produces milder symptoms than those of recurrent laryngeal loss. Loss of this nerve produces voice fatigue and a decrease in the range of the voice.

Extent of surgery

A debate rages over how much of the gland to remove when a cancer is present in the thyroid. Most of the debate concerns small thyroid cancers –

those that measure less than 1.5 centimetres in diameter. The survival rate 19_031727 ch13.qxp 9/6/06 10:46 PM Page 153

Chapter 13: Going In: Surgery on the Thyroid Gland
153

for this size cancer seems to be just as good whether a total thyroidectomy or less than a total thyroidectomy is done. Less than a total thyroidectomy leaves a small amount of thyroid tissue behind, to protect the recurrent laryngeal nerve on one side.

A total thyroidectomy is an attempt to remove all visible thyroid tissue. The surgery is extensive, more difficult to perform than partial removal of the thyroid, and results in more frequent damage to parathyroids and nerves.