Peripheral Arterial Disease (PAD)

Atherosclerosis is the narrowing or hardening of arteries by fatty deposits.

The type of arteries that are frequently affected by this are:

• Heart (Coronary)
• Lower Limbs
• Neck (Carotid)

A Lower limb Peripheral Arterial Disease (PAD) occurs when:

• An artery is affected by atherosclerosis
• Its lumen becomes narrowed or occluded
• Over time, the blood supply to the corresponding organ will diminish

The reduction in blood supply caused by atherosclerosis to the lower limbs may lead to the following problems:

• Higher cardiovascular risks throughout the body (e.g. heart attack and stroke)
• Deterioration in walking capacity
• Chronic pain in the foot and toes
• Ulcer or gangrene; and even loss of the limbs, depending on the severity of the disease

You are more likely to be at risk of PAD if you are:

• More than 50 years of age
• A smoker
• Suffering from diabetes, hypertension or hyperlipidaemia

Diagnosis of PAD is not difficult. First, your doctor will identify the symptoms and the medical history. Your lower limbs and pulse will be examined at various positions. Then, a clinical assessment of your feet and toes will take place. Through this, the ratio between highest ankle arterial pressure and brachial artery pressure (Ankle-Brachial Index) will be taken. A normal ratio would be >1.0, however, a narrowed lower limb artery will result in diminished Ankle-Brachial Index. Depending on the severity of the disease and other clinical findings, further investigations may be needed.

Early disease could be totally without symptoms (asymptomatic).

More severe disease can present as:

• Intermittent claudication
• Tightness or soreness of the calf muscle after certain period of walking
• Muscles responsible for walking do not get enough blood supply during exercise
• Discomfort will go away after a period of resting

Rest pain

• Pain over the extremities, usually toes and foot
• Usually gets worse at night and may even wake the patient up
• Due to a constant insufficient oxygen supply to the furthest parts of the lower limbs

Ulcer/gangrene of the foot and toe

• Blood supply to the extremities further deteriorate, worsening the healing ability
• Very minor injury to the toe or foot can result in a persistent wound
• Ulcer or gangrene (localised tissue death) may develop even without any injury

There are three goals for treatments:

• Reducing cardiovascular risk
• Preventing lower limb loss
• Restoring walking capacity and improving quality of life

To control atherosclerosis:

• Risk factors screening
• Change of lifestyle - quit smoking, low cholesterol diet, moderate exercise, weight reduction
• Anti-platelet agents - long term anti-platelet agents reduce the risk of all cardiovascular disease (eg. aspirin, plavix, ticlid)
• Statins (e.g. Simvastatin, atorvastatin, rosuvastatin a.k.a.crestor) - This is to reduce fat deposits in the arteries.

Non-surgical treatment:

• Walking exercise - regular walking exercise of at least 50 minutes, three or more times per week can help most people with intermittent claudication.
• Medication to reduce intermittent claudication symptoms are also available.

It is only indicated for certain inpatients with significant symptoms. It aims to improve the blood supply to the affected tissues. However, if ulcer or gangrene is already set in, surgical debridement (removal of dead, damaged, or infected tissue to promote healing) will be needed.

1. Minimally invasive endovascular intervention

Coronary Angioplasty and Stenting

Coronary artery narrowings may be treated using either medications that reduce the heart's demand for blood, or by procedures aimed at increasing the heart's blood supply. One of the two most common methods to increase the blood supply is coronary angioplasty, sometimes abbreviated as PTCA (Percutaneous Transluminal Coronary Angioplasty).

PTCA offers a non-surgical alternative to Coronary Artery Bypass Surgery.

In PTCA, a balloon mounted on a thin tube (a catheter) is advanced into your coronary artery until it lies within the narrow area. The balloon is then inflated at high pressure, often a few times, to dilate the narrowing. Upon balloon deflation, the arterial narrowing is often significantly reduced.

A stent is a small metal coil to provide support to the narrowed segment of the coronary artery after angioplasty, preventing the artery from collapsing and reducing the likelihood the narrowing will recur. Modern stents are made of stainless steel or a cobalt chromium alloy and are inert to the body. Some stents also have a medication coating and these may be preferred in certain situations to further reduce the chance of repeat narrowing of the heart arteries. Nowadays, stents are frequently placed directly over the narrowed segments (direct stenting) without prior balloon dilatation.

A stent is a small metal coil that provides support to the narrowed segment of the coronary artery after angioplasty.

1.1. What to expect?

Before going through a PTCA, a coronary angiogram is done first to provide a 'roadmap'. Undergoing PTCA is also very similar to having a coronary angiogram procedure.

First, you will be injected with local anaesthetic. A plastic tube known as sheath is inserted in a large artery in the groin or wrist. Through this sheath, a catheter is advanced to the mouth of the narrowed coronary artery. A thin wire is then threaded through the catheter and positioned in the coronary artery. Over this wire, the balloon catheter is pushed into the artery and the balloon is positioned over the area of narrowing.

During balloon inflation, you may experience some chest discomfort, and you should report this to your attending cardiologist. Stenting is carried out in a similar manner. The procedure may take 1 to 2 hours or more depending on the complexity of the diseased artery.

Following the successful PTCA, you will be monitored in a special monitoring ward. During this period, the sheath may be kept in your groin artery for 4 to 5 hours. However, the sheath may be removed immediately after the procedure if the situation allows. After the sheath is removed, the puncture site will be compressed for about 30 minutes to ensure that there is no bleeding.

You will have to remain in bed for several hours or until the following day to ensure the puncture site is sufficiently healed before walking. Your cardiologist will determine how long you need to stay in bed before you can walk around. Following that, some blood tests and ECGs will be performed to monitor your condition. If there are no complications, most patients can be discharged on the same day or the day after.

1.2. What to prepare?

• Please inform your doctor of any allergy, in particular, allergies to seafood, iodine, X-ray contrast medium and pain relieving medications.
• Please inform your doctor if you have a history of peptic ulcer disease, recent strokes, or bleeding tendencies.
• If you are suffering from diabetes mellitus and you are taking a medication called metformin, please inform your doctor and you would need to stop this particular medication for at least 2 days before and after Angiography.
• Upon discharge, you will be given two anti-blood clotting medications - aspirin and either ticlopidine or clopidogrel. Your cardiologist will advise you on the optimal length of time you should continue taking the latter two medicines (ticlopidine or clopidogrel), which can range from one month to one year. However, aspirin should be taken indefinitely to prevent future heart attacks, unless instructed by your cardiologist.

1.3. What are the success rates?

The success rate of coronary angioplasty is usually about 95%, depending on the nature of your coronary narrowing. However, in about 5% of cases, the procedure may be unsuccessful and the artery remains narrowed. In very few patients (about 1%), urgent bypass surgery may be required if the procedure is complicated.

There is a possibility of a recurrence of the narrowing of the coronary artery in the 6 months following the initial successful angioplasty or stenting, and you would usually feel a chest discomfort should it happen. If you feel a chest pain, you should seek medical attention immediately and inform your doctor.

1.4. What are the potential risks or complications?

Major complications like heart attacks, abnormal heart rhythm, stroke and death occurs in less than 1% of the patients undergoing PTCA.

Less serious complications like bleeding from the puncture site, bruising and swelling of the puncture site, and blood clot formation in the artery where the sheath is insert occurs in 1-3% of the patients.

Overall, the procedure is very safe and well-tolerated.

1.5. Home Care

As a patient:

• Resume normal daily activities.
• Notify the doctor at once if you experience bleeding or increase bruising at the puncture site; or when you experience a recurrence of symptoms, such as breathlessness or decreased exercise tolerance.
• Comply with regular follow-up visits.

2. Arterial Bypass surgery

Coronary Artery Bypass Surgery is an operation that is carried out to improve the flow of blood to the heart muscle in people with coronary heart disease where the coronary arteries are severely narrowed or blocked.

The operation involves taking blood vessels from other parts of the body and attaching them to the coronary arteries past the blockage. The blood is then able to flow around, or "bypass" the blockage. If more than one artery is blocked, you may need more than one bypass.

2.1. How should you prepare for the surgery?

• Stop smoking if you are a smoker. You should stop smoking because smoking is a risk factor for coronary heart disease. Your heart disease will not improve if you continue to smoke. It also increases your risk of complications from the surgery.
• Talk to your doctor or other people who have had the surgery. Knowing what to expect may help reduce your anxiety before the operation.
• Plan for your care and recovery after the operation. Allow for time to rest, and try to get help for your day-to-day activities.

2.2. What happens during the surgery?

• Coronary artery bypass surgery is performed by a team of surgeons.
• You will be under general anaesthesia throughout the procedure.
• The operation takes three to six hours, depending on how many blood vessels need to be bypassed.
• A cut is made in the centre of the chest at the breastbone to allow the surgeon to see the heart.
• Another cut may be made in your leg to remove a vein that will be put in your chest. (In addition, an artery in the chest, called the internal mammary artery, can be used).
• If a vein is used for the bypass, one end of it is sewn into the aorta (the main artery from the heart to the body). The other end is sewn into the area beyond the blockage in the coronary artery.
• In the case of the mammary artery, the lower end of this artery is cut and attached to the coronary artery beyond the blockage.
• In either case, the blood then used the new vessels as a detour to bypass the blockage.
• When the surgery is finished, your chest is closed with stitches.

2.3. What are the potential risks or complications?

• If you are healthy and under the age of 60, your risk of serious complications is 1%. If you are older, and especially if you are having chest pain, your risk of serious complications is 2% to 10%.
• There are always some risks when you have general anaesthesia. Discuss these risks with your doctor.
• There is a risk of infection or bleeding from this operation.
• New blockages can develop in the bypassed vessels. This might require another heart catheterisation and surgery. It is important to make changes to your lifestyle to decrease the risk of blockage.
• There is a risk of stroke during and after the operation.

2.4. What happens after the surgery?

• You will go to the intensive care unit (ICU) where you will stay for several days or as long as you need for observation. An electrocardiogram (ECG) monitor will record the rhythm of your heart continuously.
• You will have respiratory therapy to prevent any lung problems, such as a collapsed lung, infection, or pneumonia. A nurse or therapist will assess you with breathing exercises every few hours. Ask for pain medication if you need it.
• You will have physical therapy, which includes walking around the hospital and other strengthening activities. You will learn how to move your upper arms without hurting your breastbone.
• You will learn how to live a healthy lifestyle, such as choosing foods that are low in fat, cholesterol and salt, exercising regularly and not smoking.

2.5. Home care

• Have a relative or friend pick you up on the day of your discharge.
• You will not need nursing at home, but it will be good to have someone help you with your shopping and also to support you for the first 10 days or so.
• Follow up with the pre-arranged check up at the hospital with your doctor.
• Full recovery should take about three months.

2.6. When should you call the doctor?

Call the doctor right away if:

• You develop a fever
• You become short of breath
• You have chest pain that becomes worse despite taking painkillers

Call the doctor during office hours if:

• You have questions about the operation or its result
• You want to make another appointment

3. Combination of endovascular intervention and bypass surgery

This combination is used to treat patients with more complicated arterial occlusive disease.

4. Endarterectomy

The removal of atherosclerotic plaques by making an incision over the particular segment of the artery to improve blood flow.

5. Minor amputation and wound debridement

If ulcer or gangrene of the toe and foot has already set in, minor amputation or wound debridement may be necessary to ensure rapid recovery and also to restore the walking ability of the individual. The need for this surgery very much depends on the site and severity of tissue loss.

6. Multi-disciplinary approach

Besides vascular specialists, we provide a comprehensive care to PAD patients by teaming up with:

• Physicians
• Endocrinologists
• Anaesthetists
• Podiatrists
• Wound-care nursing specialist
• Rehabilitation specialists

With proper treatment and care, the majority of PAD patients with tissue loss will be able to heal up the ulcer/gangrene, avoid limb loss and walk again.