Carotid artery disease
Carotid artery disease occurs when the major arteries in the neck, called the carotid arteries, which supply blood to the brain in the neck become narrowed or blocked. This is more likely to happen as people get older and it may not cause any symptoms in its early stages. The carotid arteries are normally smooth and blood can flow freely through them but in some people a sticky substance called plaque can build up in the arteries causing them to narrow. As the plaque builds up it becomes unstable and can rupture and clumps of plaque and blood clot are carried in the blood stream and lodge in the arteries of the brain. This cuts off the blood supply to an area of the brain and part of the brain dies – this is called a stroke. A stroke can cause blindness, loss of speech and/or paralysis of one side of the body. Treatment of carotid artery disease can prevent a stroke if detected early enough.
How can carotid artery disease be prevented?
Stopping smoking, exercising regularly, eating a healthy diet and maintaining a healthy weight are all good measures to take to prevent carotid disease or slow the changes associated with it. In addition, controlling such factors as blood pressure or high cholesterol also helps, as does the proper management of diabetes.
What are the symptoms of carotid artery disease?
Carotid artery disease may not cause any symptoms in its early stages and can only be detected by carotid artery screening examinations such as Duplex ultrasound scan. Unfortunately, in the majority of cases, the first sign of carotid artery disease is a stroke but in 15% of patients there are warning episodes prior to a stroke called transient ischaemic attacks or TIAs. Symptoms of TIAs include feeling weakness, numbness or a tingling sensation on one side of the body, being unable to control the movement of a limb, losing vision and being unable to speak clearly. The symptoms of TIAs usually last less than 24 hours and resolve completely but a doctor should always be consulted immediately.
How is carotid artery disease treated?
The treatment of carotid artery disease depends on the severity of the condition and whether or not symptoms are being experienced. As a first step patients need to have a consultation and carotid ultrasound scan with an experienced vascular surgeon to determine the severity of the carotid artery narrowing. The consultant will ask you about your general medical condition and lifestyle to get an overall picture of your health. Lifestyle changes and medication may be recommended if the disease is mild or surgery may be recommended if the carotid artery disease is severe and the artery is very narrow and the operation is known as a carotid endarterectomy. A carotid endarterectomy is performed to remove the plaque that is blocking the artery and causing the reduced blood flow to the brain leaving a wide open artery. Patients are usually in hospital for two to three days when undergoing a carotid endarterectomy and the procedure is associated with a very good prognosis when performed by a qualified and experienced vascular surgeon
Arterial aneurysms
An arterial aneurysm is an abnormal dilatation (ballooning) of an artery caused by a weakness in the wall of the artery. The commonest cause of weakening of the wall is atherosclerosis – a hardening of the arteries.
Generally an artery is called aneurysmal when it increases to twice its normal size. Any artery in the body can develop an aneurysm but for some reason some arteries are more commonly affected than others. In particular the main artery in the abdomen, the aorta, is commonly affected, so are the main arteries in the pelvis – the iliac arteries – the femoral arteries in the thigh and the arteries behind the knee – the popliteal arteries.
The main risks of aneurysms are either that they burst, leading to life-threatening bleeding, or they block, cutting off the blood supply to the limbs. Aneurysms are more common in people over the age of 60. They are more common in people who have high blood pressure and/or smoke and aneurysms can run in families, particularly brothers because men are more commonly affected than women.
Abdominal Aortic Aneurysm (AAA)
An Abdominal Aortic Aneurysm (AAA for short) is an abnormal dilatation (ballooning) of the main artery in the body – the aorta. The aorta is the main artery that carries blood away from the heart and all other arteries which supply blood to the head, limbs and body organs come from the aorta. The part of the aorta below the kidney arteries and above the pelvic (iliac) arteries is particularly prone to become aneurysmal.
Diagnosis of AAA – The majority of AAA cause no symptoms and are discovered by chance. A routine examination by a doctor or an ultrasound scan performed for some other reason may pick up the presence of an aneurysm. Alternatively, some patients may notice an abnormal pulsation in the abdomen.
Investigation of AAA – The majority of AAA’s can be diagnosed by a simple ultrasound scan which also provides an accurate measurement of size. The risk of rupture of AAA’s is related to size – those bigger than 5.5cm in diameter are at risk of rupture and require surgical repair. Smaller aneurysms are monitored with ultrasound scans every 3-6 months and surgery is only considered if they increase in size or start to cause pain or other symptoms. When an aneurysm requires surgical repair, other investigations are arranged including a CT body scan which provides accurate anatomical information regarding the aneurysm so the operation can be planned in more detail. Other investigations to measure the function of the heart, lungs and kidneys may also be arranged as surgery tends to put a strain on these organs.
Treatment of AAA – surgical repair of AAA’s is a major operation requiring 7-10 days in hospital. An incision is made in the abdomen and normal aorta above and below the aneurysm is dissected, while blood flow through the aneurysm is stopped by the application of vascular clamps. The aneurysmal section of the aorta is then replaced by sewing in a tube of special vascular graft material. Blood flow is restored and the abdomen closed. Commonly, patients recover from aneurysm surgery in the intensive therapy unit (ITU). Clamping of the aorta – in order to repair the aneurysm – temporarily cuts off the blood supply to the lower half of the body and puts a strain on the heart, lungs and kidneys. The function of these organs needs to be monitored very carefully and appropriate treatment given if required. Sometimes the circulation to the legs can become blocked and further operations to restore the circulation is required. Bleeding from the repaired aorta can occur. Overall, the incidence of major complications is in the region of 5% but is increased in those patients with pre-existing disease. Other complications include erectile dysfunction in men, graft infection, wound infection and limb ischaemia.
Recovery – most people are ready for discharge from hospital within 7-10 days but if complications occur the stay is longer. Many patients report that it takes at least six weeks to feel as well as they did the night before surgery. The good news is that once patients have recovered, they can return to normal activity and a normal life-expectancy.
Endovascular aneurysm repair (EVAR)
EVAR is a minimally invasive method for the repair of thoracic and abdominal aortic aneurysms. Instead of an incision in the abdomen and/or chest, incisions are made in both groins and stenting devices are inserted through the femoral arteries into the aorta. Once in position the stents are expanded inside the aorta to repair it. Not all aneurysms are suitable for EVAR.
Anaesthesia – Generally the operation is performed under general anaesthesia but sometimes the operation is performed under local anaesthetic or epidural.
Surgery – an incision is made in each groin and the femoral arteries exposed. Specialised wires and catheters are inserted through the femoral arteries into the aorta. X-rays are performed and intravenous dye injected to determine the correct position of the stent. The stent is expanded inside the aorta to repair it. Usually a number of stents are inserted to repair the aorta and the iliac arteries.
Sometimes the stenting procedure is combined with an operation to repair more complex aneurysms and there are lots of variations.
Complications of EVAR – The complications of EVAR are similar to open aneurysm repair in that the function major organs, for example the heart, lungs and kidneys may be affected. However, it is generally considered to be less common with EVAR than with open repair. However EVAR does not last as long as open surgery and redo EVAR procedures are more common.
The incisions in the groins may bleed resulting in haemorrhage, false aneurysm and/or bruising. The groin may develop swelling caused by excess tissue fluid – seromas – which may become infected and need drainage and/or antibiotics.
Long term complications – Once a stent is inserted into the aorta it needs to be monitored every three months for the first year and yearly thereafter. This is because problems can develop with the stent in about 20% of cases. If detected early enough they can normally be corrected before they cause any harm.
Any artery in the body can develop an aneurysm but for some reason some arteries are more commonly affected than others.
Peripheral Vascular Disease (PVD)
Peripheral vascular disease is the narrowing of one or more arteries (blood vessels) and it mainly affects arteries which take blood to the legs. This condition is also commonly referred to as ‘hardening of the arteries’.
The narrowing of the arteries is caused by the development of ‘fatty patches’ within the inside lining of arteries. The medical term for this is atheroma. The fatty patches can start off quite small and cause no problems at first, but over time they can increase in size and make the affected artery narrower. This reduces the blood flow through the affected section of artery, resulting in tissues having a reduced blood flow, leading to symptoms developing.
Risk factors and symptoms
Lifestyle risk factors which increase the likelihood of a person developing PVD include smoking, obesity, lack of exercise, an unhealthy diet or excess alcohol. Other factors that increase the risk of developing PVD include high blood pressure, high cholesterol and diabetes. Advancing age and family history are often additional risk factors.
The typical symptom is pain in the calf, thigh or buttock muscles when walking. This represents the earliest stage of peripheral vascular disease and is called ‘intermittent claudication’. When a person is walking, the muscles need extra blood to provide more oxygen to the muscles and remove toxins. If the artery is narrowed the extra blood cannot be delivered to the muscles. This results in the muscles being starved of oxygen and toxins building up, causing the muscles to ache and become weak. In the early stages of PVD, this can occur after walking quite a long distance (for example, half a mile). But if the narrowing of the arteries becomes worse, pain can be felt after just a 100-yard walk. Eventually a person may only be able to walk a few yards before experiencing pain. Resting usually relieves the pain within two or three minutes and then it is sometimes possible to walk further.
When the arteries are severely narrowed or blocked, the arteries cannot supply enough blood to the legs and a person develops what is known as ‘rest pain’. Typically, rest pain develops in the toes and feet and particularly at night when the legs are raised in bed, losing the help of gravity to supply blood to the feet. Eventually, the feet are painful all through the day and sleeping is very difficult due to the pain. Ulceration and gangrene can occur in the most extreme cases. Any wound requires more blood than normal in order to heal. If that extra blood is not available, the wound never heals and in fact dies back, resulting in ulceration and dry-black gangrene. Urgent medical attention is required here.
Treatment
In the earliest stages of the disease, when a person is experiencing pain on walking, the correct treatment at this time can prevent progression of symptoms. The following measures are very important in the management of PVD:
- Stopping smoking– This is the single, most effective treatment and stopping is essential to improve walking distance and prevent progression of the disease.
- Walking – This has been shown to be the best form of exercise to improve the symptoms of PVD and should be undertaken daily. Regular exercise stimulates small arteries in the legs to enlarge and bypass the narrowed arteries, thereby improving the blood supply.
- Lose weight– Excess weight means that your muscles have to work harder in order to walk. Losing weight reduces the demand on the muscles and can cure symptoms of PVD alone.
- Aspirin – Taking an Aspirin is usually advised at a dose of 75-150mg a day to thin the blood. Alternatives are available for people who cannot take Aspirin.
- Cholesterol – Cholesterol-lowering medication is usually advised to help prevent the build-up of atheroma.
- Other medical conditionssuch as high blood pressure and diabetes should be kept well under control to prevent progression of PVD.
If symptoms do not improve with exercise and conservative management, a special x-ray called an angiogram would be needed. Under local anaesthetic, a needle is inserted into an artery – usually in the groin – and dye is injected. X-rays are taken as the dye is carried in the blood down the leg arteries. This shows where the arteries are narrowed or blocked. An angioplasty involves a tiny balloon being inserted into the artery and inflating it where it is narrowed. Stretching the narrowed artery can improve the blood supply to the leg and therefore improve the symptoms.
Arterial bypass surgery can be performed when angioplasty has failed or is not possible. The operation is performed to bypass blocked arteries and improve the blood supply to a limb.
