Peripheral Arterial Disease

PAD is defined as a muscular pain brought on by walking due to a reduction in lower limb blood supply because of a narrowing or blockage of the major arteries supplying the legs. Patients may complain of crampy pain in their calves, thighs or buttocks which is termed intermittent claudication.

As described on this webpage for other vascular disease processes, poor lower limb circulation is often associated with patients as they get older. Increased rates of PAD are reported in patients with a past medical history of heart disease (angina, heart attack), cerebrovascular disease (stroke, TIA) and other cardiovascular risk factors including high blood pressure and high cholesterol.

Early onset and often more severe disease presentation can be found in patients who smoke, have diabetes and impaired kidney function. Patients with a poor lifestyle who take infrequent exercise will usually present earlier with increased symptoms.

There are some individuals who have lower limb circulation problems and no obvious risk factors. These individuals probably have a genetic predisposition.

The process of blood vessel deterioration over time is called “atherosclerosis” . Narrowing within the arteries itself is caused by the build-up of “atheroma” which is a fatty material that develops within the lining of artery walls. All people develop small amounts of atheroma in their arteries throughout their lifetime. Some patients with the risk factors above, particularly those who smoke, form extensive atheroma and subsequent plaques more quickly. As the amount of plaque builds up over time, the artery can gradually narrow and eventually block, resulting in a significant limitation of blood supply to that limb. Some patients may develop narrowing in multiple areas of the body or at multiple points on the same artery.

This process can occur in any artery in the body leading to peripheral arterial disease in the legs, angina or a heart attack if present in the heart and a stroke if present in the arteries supplying the brain.

All muscles require oxygen to be able to function. Lower limb blood supply delivers oxygen to these muscles which require increased amounts during periods of exertion such as walking or running. If blood supply to the lower limb is reduced because of PAD, the leg muscles do not receive adequate amounts of oxygen leading to muscle cramps and pain. This pain can increase to a level that then causes the patient to stop walking. Cessation of walking subsequently leads to a reduction in oxygen demand. Although PAD arterial narrowing causes symptoms when walking, subsequent rest means enough blood can now get to the affected leg and the leg pain gradually decreases over the next few minutes.

The more severe the blood vessel narrowing, the quicker the pain can come on when walking, the shorter the patient can walk and the longer it takes for the pain to settle after resting. This is why your vascular specialist will ask how far you walk before you have to stop and rest which is called the “Claudication Distance”.

As your peripheral arterial disease progresses over the next period of months or years, this claudication distance can reduce further as the narrowing in the blood vessel increases. Further deterioration can cause insufficient blood supply to your lower limb even at rest which is called “Critical Ischaemia”. Symptoms of critical ischaemia include “Rest Pain” which means that a patient will have severe pain in the foot present when resting without actually walking or exerting themselves. Patients may also notice the development of cuts, wounds or ulcers in the feet that do not heal. This is a serious condition which requires urgent vascular assessment as it can result in Limb Amputation .

Treatment options for peripheral arterial disease include conservative, medical, radiological and surgical modalities.

Conservative treatment options include generalised lifestyle improvements such as healthy eating, weight loss, an increase in exercise, minimising stress if possible and smoking cessation.

Regular exercise improves overall cardiovascular well-being and it has been scientifically proven to increase your walking ability. Current research clearly shows that walking for 30 minutes every day continuously (not intermittently around a shopping centre) can potentially double your walking capabilities after 3 to 6 months.

If you think of the narrowing of the main artery in your legs as a “Motorway” with one or two lanes closed, it is obvious that flow is going to be insufficient at peak travel times such as when you are walking rather than resting. Walking exercises do not open the motorway again – they serve to increase and improve the quality of “A, B and C” roads in your legs to help improve blood flow and reduce the strain on the motorway. This process is called “Collateralisation”.

It is important to realise that you cannot suddenly go from walking only a few minutes to 30 minutes overnight. This is a gradual process where you need to train your body and legs and it takes time. It can also be very sore at times. However, your vascular specialist will emphasise that walking through the pain will not cause you any harm – IN FACT it will serve to improve lower limb collateralisation as discussed above.

Walking on a daily basis is the best exercise for your PAD. Walk until the pain develops, then rest for a few minutes. Carry on walking when the pain has eased. Keep this up for at least 30 minutes each day and if possible even extend to an hour a day and try to even walk through the pain.

Regular exercise will aid weight loss which can reduce overall stress on your heart and reduce your risk of developing diabetes.

Medical treatments are used to improve your cardiovascular risk factor profile and reduce the progression of your peripheral arterial disease. Prior to prescription of any medication please advise your vascular specialist or general practitioner if you have had any issues or reactions to certain medications and then an alternative medication may be considered.

Antiplatelet Therapy – Aspirin and Clopidogrel reduce the stickiness of platelets in your blood to limit your PAD disease progression and also reduce your risk of heart attack or stroke. Clopidogrel is used in patients who have had a history of stomach ulcers. After some clinical treatments, your vascular specialist may recommend both aspirin and clopidogrel at the same time.

Cholesterol Lowering Medication – Statins are prescribed to improve your cholesterol levels in the blood where higher levels have been shown to increase the progression of your PAD. Some research has also suggested that statin therapy can aid your walking capabilities.

Blood Pressure Medication – A wide range of medicines are available to treat high blood pressure. Regular blood pressure assessment and modification of medication doses over a period of many months affords optimal control rather than any sudden increase or decrease in medication.

Smoking Cessation – Multiple therapies are now available to assist you including patches, oral nicotine replacement and more specialised cessation medications. Stopping smoking is the greatest preventative treatment for PAD and vascular disease elsewhere in the body.

Diabetic Control – Keeping your blood sugars within reasonable limits is important to minimise your risk of PAD related complications including amputation and other cardiovascular events such as a heart attack or stroke.

Other PAD medications such as cilostazol pentoxifylline or naftidrofuryl may also be prescribed as therapies to specifically improve your walking distance.

Prior to your angiogram, your vascular specialist will try and ensure that your cardiovascular risk factors have been evaluated and optimised as much as possible. It is important to ensure that you have been prescribed antiplatelet or anticoagulation treatment and statin medications if it is safe to take these medications.

It is also important that you have had a recent blood test to evaluate your kidney function. This may have already been performed by your General Practitioner or Vascular Specialist during your clinic appointment. Patients with reduced kidney function may require additional intravenous fluid on the day of their angiogram or in some circumstances may not proceed with an angiogram due to concerns about your kidneys.

Diabetic patients prescribed metformin tablets should not take it on the day of the procedure and for 48 hours after the procedure.

If you are on warfarin or other anticoagulation medicine, you may be asked to stop taking those tablets for 2 or 3 days before the procedure.

You will be advised regarding all of these factors during your radiology pre-assessment which may be performed in person through attendance at the hospital radiology department or completed during a telephone call.

Most angiogram procedures are performed as day cases under local anaesthetic. Occasionally, due to complexity of the procedure or due to significant patient medical co-morbidities, an overnight admission to hospital is warranted.

It is important to make sure you have some family support at home following your procedure or alternative support from friends.

Most patients will have a radiology pre-assessment completed in person or via a phone call from one of the interventional radiology team members prior to their procedure for completion of procedural clinical documentation.

Most patients attend fasting with no fluids or food taken from midnight on the day of their procedure.

It is important that you can lie flat for the duration of the procedure which can sometimes take between 30 and 90 minutes to complete.

Your vascular surgeon or interventional radiologist will visit you before the procedure and ask you to sign a consent form once they have explained the treatment to you. Please ask questions if you are unsure about any aspect of the procedure.

Angioplasty and stenting is successful in approximately 80% to 90% of patients. Between 20% and 30% of patients experience recurrence of their symptoms in the coming years and may be considered for repeat treatment. In the small percentage where endovascular treatment does not work, the patient may be considered for a surgical bypass operation as an alternative depending on their symptoms, arterial anatomy and overall fitness for an operation.

Your vascular specialist will also try and maximise the chances of your procedure lasting for a longer period of time with modern innovative strategies including the use of “drug-eluting balloons” and “drug-eluting stents”.

Endovascular treatment of peripheral arterial disease is indicated to improve lower limb arterial blood supply to reduce walking induced pain called intermittent claudication, reduce foot pain at rest called critical ischaemia, assist healing of arterial ulcers and limit patient limb loss through amputation due to poor blood supply. Risks of intervention may be divided into;

The vascular specialist performing your angiogram may not be the same clinician you saw in the clinic. After your angiogram, a report of the procedure will be sent to this clinician to ensure a review out-patient clinic appointment is made approximately 6 to 12 weeks following your procedure to discuss your treatment and assess your recovery. If you have a foot wound, this will need continued management with re-application of dressings and earlier review assessments on a regular basis.

This will all depend on your current symptoms and varies widely for each patient. Your vascular specialist will speak to you after your angiogram.In patients who can still manage to walk a few hundred yards, your vascular specialist will most likely suggest for you to continue on your medical treatment and walk as much as possible. Although this may be quite a challenge, it avoids the need for an operation where the risks may outweigh the possible benefits for you.

In patients, with severe limitations to their walking or those who are at risk of losing their limb without an intervention, your vascular specialist will discuss the need to consider an operation to improve the blood supply to your limbs. Although all operations have a risk, it may be deemed appropriate in patients as a limb-saving procedure.

Sometimes an operation may not be appropriate if you have multiple or significant medical problems which would mean you would not be able to tolerate or survive such an intervention. Some patients may also have such severe disease in their blood vessels that a bypass operation is not possible.

Your vascular surgeon will complete a thorough assessment of your current symptoms, examine your lower limbs and review all your previous blood vessel investigations. At this stage, they will discuss possible operative options to improve blood flow to your limb which normally includes an endarterectomy, bypass procedure or a combination of these options. Sometimes an angiogram followed by angioplasty or stenting can be completed as well during your operation.

An endarterectomy is a procedure to improve lower limb blood supply performed by coring out the narrowed or blocked area in the actual blood vessel followed by placement of a patch over the top of the opening in the blood vessel to make it wider. This allows more blood to get through to the affected limb. An endarterectomy is usually suggested if the narrowed or blocked area is not very long in length.

An arterial bypass is a procedure to improve lower limb blood supply performed by connecting a substitute vessel or tube from an area above a blockage to an area below the blockage. An arterial bypass is usually suggested if the narrowed or blocked area is longer in length.

Prior to your lower limb revascularisation procedure, your vascular surgeon will try and ensure that your cardiovascular risk factors have been evaluated and optimised as much as possible. It is important to ensure that you have been prescribed antiplatelet or anticoagulation treatment and statin medications if it is safe to take these medications.

If you are on warfarin or other anticoagulation medicine, you may be asked to stop taking those tablets for 2 or 3 days before the procedure or sometimes longer.

Smoking cessation is exceptionally important to try and optimise your short- and long-term outcomes following your lower limb revascularisation procedure.

You will require an anaesthetic pre-assessment a few weeks before your surgery which includes a clinical evaluation, blood work-up and some additional investigations for your heart ( Electrocardiogram-ECG and Echocardiogram-ECHO ) and your lungs (Chest X-ray and Pulmonary Function Tests-PFTS ). It is important to inform your specialist of all your medical conditions and current medications which may be amended to optimise your recovery particularly those medications prescribed for the treatment of diabetes, heart or lung disease.

Most anaesthetic assessments and subsequent heart and lung tests can be performed during out-patient attendances prior to your planned surgery date. At the Royal Victoria Hospital, patients are usually admitted the day before surgery.

Patients undergoing lower limb revascularisation procedures are usually admitted the day before surgery. Your vascular surgeon will visit you before the procedure and ask you to sign a consent form once they have explained the treatment to you. Please ask questions if you are unsure about any aspect of the procedure.

Due to the complex nature of some lower limb revascularisation procedures, patients may require a High Dependency or Critical Care Unit bed following your surgery. Occasionally these specialised beds may not be available on the day of your surgery leading to subsequent postponement of your surgery to a different day on the same admission or occasionally discharge from hospital and re-booking of surgery on a different admission date.

Your vascular surgeon will advise you accordingly and will wish to apologise for such an event if it happens.

You will be advised regarding fasting periods before surgery which is usually at least 6 hours before a general anaesthetic.

Most patients will be fasted from midnight on the day of their lower limb revascularisation procedures. As many other aspects can vary depending on your procedure, patients will have an individualised care plan.

Success rates of surgery to treat peripheral arterial disease depend on the location and severity of your disease and the type of replacement tube (vein or plastic) used to create the bypass graft. An 80% to 90% success rate over 5-years can be achieved if the bypass is created in the lower abdomen or upper legs compared to approximately 50% to 70% if the bypass has to extend to a smaller vessel below the knee. A bypass graft has a better chance of longer term success if you are a non-smoker or have stopped smoking, continue to take all your medications correctly and if the surgeon is able to construct the bypass graft using your own vein obtained from elsewhere in your body rather than an artificial (prosthetic) graft.

Lower extremity revascularisation including common femoral endarterectomy and/or patch angioplasty and/or arterial bypass is indicated to minimise pain, improve blood supply to the extremity, help foot ulcer healing and reduce risk of amputation. Risks of intervention may be divided into;

The type of arterial bypass operation performed will depend on the location of the narrowing or blockage and the planned position of the bypass graft above and below the diseased vessel. The substitute tube (bypass graft) is usually your own vein from the same limb, your own vein from a different limb or a plastic artificial tube. The bypass graft is connected to healthy artery above and below the blockage so that increased amounts of blood reach the previously starved tissues. These operations tend to be performed on patients who have more severe PAD with associated rest pain, infection and tissue loss or in patients with an arterial narrowing or blockage which cannot be treated with endovascular angioplasty or stenting techniques.

After you are positioned appropriately on the operating table, the affected lower limb skin area is shaved (if required), cleaned with aseptic fluid and surgical drapes are then applied to maintain a sterile operative field for the operation. A vertical groin incision is performed to expose the femoral artery and the arteries it divides into called the superficial femoral and profunda femoris arteries. A further incision is completed lower down the affected limb, usually on the inside of the knee, to expose the healthy artery below the narrowing or blockage. At this time, the vascular surgeon will complete a further long incision which usually connects the two wounds to dissect out your own vein for use as the bypass graft. The surgeon will then create a tunnel in a deeper layer in your leg for positioning of the bypass graft to protect it. Blood thinning medication called heparin is then administered via one of your veins by the anaesthetist. Clamps are applied to the arteries above and below the area of narrowing or blockage that has caused your symptoms. Both arteries are then opened and subsequently cleaned out to remove any evidence of disease if required. Once your vascular surgeon is content the two vessels above and below the diseased segment are satisfactory, they will then suture the bypass graft separately to these two areas therefore bypassing the narrowed or blocked arterial segment.

Once the bypass graft has been sutured in place, the clamps are subsequently removed from the artery to make sure there are no leaks from the patch. When your surgeon is satisfied that normal blood flow in the artery has been restored, the wounds are then closed carefully with layers of sutures. The skin sutures are designed to dissolve by themselves and do not require removal. Sometimes your surgeon will use skin clips instead to close the wound which then require removal between 10 and 14 days following your surgery. Occasionally, a small drainage tube is inserted in the groin or calf to drain off any accumulating fluid or blood following the surgery. The operation is now complete and you will be taken to the recovery area. The operation usually takes between 2 to 5 hours.

Although your surgeon will have discussed initial aspects of your lower limb revascularisation procedure during your initial out-patient clinic attendance, they will also meet you before the operation and go through all the required information regarding your planned intervention. The surgeon will then ask you to sign a consent form for your lower limb revascularisation procedure after they have explained the procedure to you.

You will have all aspects of surgery discussed with you ensuring you are aware of why the surgery is required and what risks and complications are associated with the surgery.

You will have an opportunity to meet your anaesthetist before your surgery who will advise accordingly what type of anaesthesia will be required. For lower limb revascularisation procedures, general, spinal or local anaesthesia can be used.

Patients are normally taken to the operating department in their own vascular ward beds. All staff members will introduce themselves to you as we know you will be very nervous pending your procedure. After you are checked into the theatre environment you will meet your anaesthetic team. Once your anaesthesia is complete, various tubes will be inserted into your bladder, wrist artery and arm veins. This will allow you to be accurately monitored and can facilitate administration of medications, fluid or blood products during your procedure.

Not necessarily. Occasionally you may still require additional blood products from donors during your lower limb revascularisation procedure or in the post-operative period.

Please make your vascular specialist aware as early as possible if you have personal or religious concerns regarding the administration of donor blood products.

Prior to your surgery, the anaesthetic team will have discussed post-operative pain relief which can be provided using oral pain relief tablets or a patient-controlled anaesthesia where you, the patient, press a button to provides pain relief at given intervals. Most patients will experience some discomfort after any major procedure. However, your specialist vascular team will do their best to try and minimise any pain you may have during your post-operative recovery. It is well researched that optimisation of your pain relief after your procedure affords you a better outcome which is exactly what your vascular team wish for you.

All patients are transferred to the Operating Theatre recovery area immediately following surgery for a period of time to ensure you have stabilised after your procedure. Following this period which is usually at least a few hours, you may be transferred back to the vascular ward if you have minimal medical problems and were relatively fit and healthy prior to your procedure. The nurses and doctors will try and keep you free of pain by administering oral pain relief tablets, pain killers by injection or using a machine that you are able to control yourself by pressing a button called patient controlled analgesia (PCA). You will also be given a daily injection of heparin under the skin to reduce the risk of clotting in your veins (known as “deep vein thrombosis”).

During your anaesthetic assessment, you vascular team may have decided that a high dependency or intensive care bed is required for your initial post-operative recovery period. When you are deemed stable and require no additional breathing or heart support, you will be transferred back to the vascular ward. Unfortunately, when a high dependency or intensive care bed is unavailable in the hospital, your surgery may be postponed or re-scheduled.

As you recover from surgery, your normal diet and medications will be restarted. The physiotherapists may visit you after your operation to help with your breathing to prevent you developing a chest infection and with your mobilisation to get you walking again. You will be encouraged to mobilise which should gradually be increased until you are fit enough to go home.

Following your admission the day before your lower limb revascularisation procedure, most patients are discharged home after 2 or 3 days following a femoral endarterectomy or after 2 to 5 days following a lower limb arterial bypass.

Most skin wounds can be closed with an invisible suture layer (subcuticular) and you will only require a dressing over the wound for the first few days. If your surgeon uses external sutures or skin staples (clips), these remain for between 10 and 14 days after your procedure. Some patients will have sutures removed in hospital if they are still an in-patient while the majority will have removal arranged by their district nurse following their discharge who will also complete a wound check.