1. What are carotid arteries?
The carotid arteries are the blood vessels that carry oxygen-rich blood to the head, brain and face. They are located on each side of the neck. The carotid arteries supply essential oxygenated blood to the large front part of the brain. This part of the brain controls thought, speech, personality as well as our sensory (our ability to feel) and motor (our ability to move) functions.
2. What is carotid artery disease?
The brain survives on a continuous supply of oxygen and glucose carried to it by blood. Carotid artery disease is narrowing (stenosis) or blockage of these arteries due to plaque build-up (atherosclerosis). The plaque can then crack, and develop an irregular surface, which is when it begins to cause problems. If a piece of plaque or a blood clot breaks off from the wall of the carotid artery it can block the smaller arteries of the brain. When blood flow to the brain is blocked, the result can be a transient ischemic attack (TIA), which temporarily affects brain function, or a stroke, which is permanent loss of brain function. Common symptoms of TIA include brief attacks of weakness, clumsiness, numbness or pins and needles of the face, arm or leg on one side of the body. The eye can also be affected resulting in loss of vision in one eye. This is called Amaurosis Fugax. Carotid artery disease is one of the most common causes of stroke.
3. What causes carotid artery disease?
Some of the causes are fixed, such as being male, having a family history of stroke or angina, or getting older. Others can be modified such as smoking, high cholesterol, high blood pressure or diabetes. If you already have peripheral arterial disease (PAD) or coronary heart disease you are at higher risk of carotid disease and stroke.
4. How is the diagnosis made?
The diagnosis is usually made with an ultrasound scan of the arteries in the neck (a duplex scan), or sometimes after a CT or MR scan. Diagnosis of this condition is important because it increases the risk of you having a stroke in the future.
5. Can medication help?
All patients with carotid artery disease benefit from taking blood thinning medication such as aspirin or clopidogrel. Statins and risk factors modification, such as stopping smoking completely are also very important. There are multiple benefits from giving up cigarette smoking, including reducing the excessive tendency for blood to clot, increasing the amount of oxygen in the blood and most importantly preserving the cells lining the blood vessels which are very sensitive to the toxins in smoke.
The benefit of aspirin is to reduce the stickiness of small blood cells called platelets which adhere to the irregular surface of the plaque, but can then break off as a small clump. The benefit of a statin is partly in reducing the cholesterol, but they also appear to reduce the tendency for atherosclerotic plaques to crack and so even patients with “normal” cholesterol will benefit from taking them.
6. When should I see a Vascular Surgeon?
If you have suffered a TIA or a stroke and you have a tight narrowing in the carotid artery on the appropriate side you should be referred to a vascular surgeon for consideration of and discussion about carotid endarterectomy. These referrals are usually made by the medical team who looked after you at the time of your initial event. Referral to a vascular surgeon should be made without any unnecessary delay after the initial event. To provide the maximum benefit for patients, if carotid endarterectomy is going to be performed, it should be done as soon as possible after the initial symptoms of TIA or stroke.
7. An operation has been recommended, what will this involve?
Carotid endarterectomy may be performed if you have had a TIA or stroke. The danger is that you may suffer a major stroke in the future. There is good evidence that some patients, usually those with narrowings greater than about 50% of the diameter of the artery, benefit from surgery; carotid endarterectomy. The aim of carotid endarterectomy is to prevent you having a major stroke. The following information will help explain the process of a carotid endarterectomy operation.
Before the treatment
Before you have carotid surgery, there are a number of tests that need to be done to assess whether you are able to have the operation, and some that need to be done immediately before the surgery (pre-operative tests).
Tests to see whether you are suitable for the operation may include:
- Ultrasound (duplex) scan, MR scan or CT scan of the arteries in the neck
- Blood tests
- ECG (a heart tracing)
- CT or MR brain scan
These tests should have been done within a couple of days of your symptoms. If you are fit enough, you will be offered an operation generally within two weeks of your symptoms.
Your stay in hospital
You should bring with you all the medications that you are currently taking. You should continue to take your normal medication prior to the operation unless instructed otherwise. You will be admitted to your bed by one of the nurses who will also complete your nursing record. You will be visited by the surgeon who will be performing your operation, and also by the doctor who will give you the anaesthetic. If you have any remaining questions about the operation please ask the doctors. You will be asked to sign a form confirming that you understand why the procedure is being performed, the risks of the procedure and that you want to go ahead with the operation.
The operation – the anaesthetic
Carotid endarterectomy can be performed under regional (local) or general anaesthetic.
For local anaesthetic, the anaesthetist will make an injection into the skin of your neck to numb it. During the operation, if you become uncomfortable, the surgeon will inject more local anaesthetic. Occasionally it may be necessary to convert to a short general anaesthetic during the operation. For a general anaesthetic, a tiny needle is placed in the back of your hand. The anaesthetic is injected through the needle and you will be asleep within a few seconds. A drip is placed into a vein in your arm (wrist usually) to give you some fluids during and following surgery. Sometimes, a second drip will be placed into an artery at wrist level to permit careful blood pressure monitoring during and just after the operation.
You will have a cut running vertically down from near the angle of your jaw / ear lobe towards your breastbone. The incision is usually 10-15cm in length. Once the carotid artery is displayed, the branches of the artery are clamped to limit blood loss during the operation. A small incision is made along the artery and the plaque or narrowing is carefully removed. When the inside of the artery has been cleared, it is closed with very fine stitches. A small patch will usually be stitched to the artery to prevent further narrowing. This patch is normally a piece of animal tissue (bovine), but sometimes a material called Dacron or a vein from your leg may be used as the patch.
Occasionally a slightly different technique is used where the carotid artery is disconnected, everted and then cleared. The carotid artery is then rejoined.
If your carotid endarterectomy operation is performed under regional (local) anesthetic, the anesthetist will be able to talk to you during the operation. This is particularly useful when your carotid artery is clamped as it allows the surgeon and anesthetist to confirm there is sufficient blood supply to your brain. A shunt (narrow plastic tube) is sometimes used to maintain blood flow if clamping your artery gives you similar symptoms to your TIA or stroke. The shunt lies in a loop outside the artery, passing into the artery above and below at each end of the incision in the artery. If your carotid endarterectomy operation is performed under general anaesthetic a shunt will almost always be used.
Your surgeon may place a small plastic drain in your neck for a short period to look for bleeding and to reduce neck swelling after the operation. The wound is usually closed with a stitch under the skin that either dissolves or is removed within 24 – 72 hours.
8. Recovery after a carotid endarterectomy and aftercare
After a few hours in the recovery area in the operating theatre block you will usually be taken to the ward for up to 24 hours after your operation so that your progress can be closely monitored. Following this sort of surgery you are unlikely to feel sick, and you should be able to eat and drink again within a few hours. Your mobility will return to normal more or less immediately. There is often some swelling in the neck, but this settles within 7-10 days.
The incision on your neck will initially be very visible; however this will subside and become virtually invisible within 2-3 months.
A blood transfusion is rarely required. Sometimes there is a requirement to recover for a period in the High Dependency Unit, for example, for more intensive blood pressure control.
Most people leave hospital the following day after carotid endarterectomy. Some people do need to stay a few extra days in hospital to recover. If your skin stitch is the type that needs removing this is usually done whilst you are still in hospital. If not, it will be arranged for your GP’s practice or district nurse to remove it and check your wound.
Regular exercise such as a short walk combined with rest is recommended to provide a gradual return to normal activity.
Driving: You will be able to drive when you can perform an emergency stop safely and look over your shoulder easily. This will normally be 2-3 weeks after surgery, but if in doubt check with your own doctor. You should inform your insurers that you have had this operation. The stroke doctors or neurologists will have already informed you about the time interval for driving after a stroke based on DVLA rules.
Bathing: Once your wound is dry after 3-4 days you may bathe or shower as normal.
Work: If this applies to you, you should be able to return to work within 3-4 weeks of surgery. Your GP will advise you of this when you see him/her for your sick-note.
Lifting: There are no limitations in this area.
Medicines: You will usually be sent home on a small dose of clopidogrel if you were not already taking it. This makes the blood less sticky. If you are allergic to clopidogrel an alternative drug may be prescribed. No other changes to your medication are usually required.
9. What are the potential complications from a carotid endarterectomy?
Stroke: A small number of people, between 1 and 3 in 100, having carotid endarterectomy will have a stroke during the operation or shortly afterwards. The severity of stroke can be very mild causing little or no disability, through to severe causing major disability and death. All possible precautions will be taken to prevent this eventuality.
Other major complications: As with any major operation there is a small risk of you having a medical complication such as a heart attack, kidney failure, chest problems or infection in the wound. Each of these is rare, but overall it does mean that some patients may have a fatal complication from their operation. For most patients this risk is about 2% – in other words 98 in every 100 patients will make a full recovery from the operation.
If your risk of a major complication is higher than this, usually because you already have a serious medical problem, then your surgeon will discuss this with you. It is important to remember that your surgeon will only recommend treatment if he or she believes that the threat of stroke without operation is much higher than the threat posed by the operation itself.
Wound infection: Wounds sometimes become infected and this may need treatment with antibiotics. Wound infections for this type of procedure are rare. Infection of the inserted patch is a very rare, but serious complication.
Fluid leak from wound: The wound can bleed which may lead to swelling. Usually the swelling will settle on its own, but occasionally the wound may need further surgical attention. If you have been started on tablets to thin your blood when you were admitted for symptoms of TIA or stroke, then you may be at an increased risk of bleeding that may require a return to theatre.
Nerve injuries: These are uncommon. Skin nerves are interrupted by the incision leading to some loss of skin sensation, which may recover over time. Movement of nerves nearer the carotid artery can lead to temporary or rarely permanent loss of function. The vagus nerve provides a branch to the voice box (larynx) leading to a hoarse sounding voice. The hypoglossal nerve supplies the muscles of the tongue affecting speech slightly by reducing the tongue’s mobility. The facial nerve supplies the muscles of the face; damage to its lowest branch may lead to impaired movement of muscles around the lower jaw and neck. The risk of cranial nerve injury after carotid endarterectomy is about 5%. In most cases the nerves recover in the months after surgery.
Chest infections: These can occur following this type of surgery, particularly in smokers and may require treatment with antibiotics and physiotherapy.
How you can help yourself
If you are a smoker you should make a determined effort to stop completely. Continued smoking will cause further damage to your arteries and increases the risks of heart attacks, strokes, and problems with the circulation in your legs.
10. What are the alternatives to Carotid Endarterectomy?
Stenting has been used for carotid artery stenosis. The short term results are not as good as carotid endarterectomy. Very few Vascular Units in the UK offer carotid stenting and this is usually as part of research studies. Conservative treatment (i.e. no intervention and taking medication as per point 5 above) is a reasonable choice for some patients.
11. Further questions
If you have any further questions then please ask your doctor or the vascular nurses either in clinic if this applies to you or on the ward.