Preventing Amputation

Amputations may be described as a destructive operation, which removes a limb or part of a limb that is no longer functional and may be life threatening. It is irreversible and for the individual, it may be devastating, despite being the only step that could give comfort and save life. It is therefore natural one would consider all means of prevention.

The commonest cause of amputation in the western world is vascular disease, nearly half of these have diabetes mellitus. This accounts for more than 75% of lower limb amputations. Trauma accounts for 10% and tumours only 3% of all amputations. Upper limb amputations  account for 5% of all amputations and over 50% are due to trauma.

An amputation is generally indicated when other salvage procedures have failed to restore adequate circulation. Occasionally, it is an ‘optional’ procedure, when it  should be considered carefully, after adequate discussion with the patient and a pre-amputation consultation with the prosthetic rehabilitation team.

Prevention of amputation is therefore largely a matter of preventing vascular disease and good management of
diabetes mellitus.

Peripheral vascular disease and diabetes.
It is useful to consider peripheral disease and diabetes together as many of the features leading up to amputation are similar. There are however  some differences which will be pointed out subsequently. Peripheral Vascular Disease, also known as ‘arterio-sclerosis’ is a condition more  prevalent in westernised urban societies. It affects the arteries of the body causing hardening and thickening of the arterial walls and later causing the arteries to  narrow and eventually become blocked. When the arteries to the heart are blocked it may lead to angina or heart attacks. When the arteries to the brain are affected they cause strokes. When the arteries to the limbs are affected they cause peripheral vascular disease, ischaemia and eventually may require amputation.

The following factors are known to contribute to peripheral vascular disease:

Genetic susceptibility: It is thought that inheriting particular genes may make the individual susceptible to arterial disease. Usually an external activator is necessary to stimulate the process. The activators as yet are unknown but it could be smoking, unknown factors in the food or the environment.

Smoking: Smoking is a major causativefactor of peripheral vascular disease. A study of amputees who attended

Manchester DSC with peripheral vascular disease showed that about 90% are smokers or ex-smokers.

High Blood Pressure: Some clinicians feel that high blood pressure leads to peripheral vascular disease. Other clinicians feel the vascular disease causes high blood pressure. Hypertention remains the commonest recognised cause of stroke.

Hypercholesterolaemia: High levels of cholesterol in the blood stream are certainly a factor that increases the chances of developing strokes and heart attacks. It is likely that your genetic makeup will be responsible for your cholesterol levels in the blood. Dietary moderation of fat will partly lower your blood cholesterol. In patients with risk factors, many physicians consider a more aggressive approach to the management of high blood cholesterol with the use of ‘statins’ – modern, cholesterol lowering medication. Modern anti-cholesterol medication together with diet control is probably a more assured way of lowering the cholesterol levels.

Exercise: There is increasing evidence that aerobic exercises done three times a week will have a beneficial effect for those already with heart disease. It is also known that people with claudication (pain in the muscles of the legs that occurs after walking some distance) is improved by regular exercises to the legs.

Diabetes: Diabetes mellitus is a condition where the body is unable to control the level of circulating sugar in the blood. This results from the body producing inadequate levels of insulin, or despite producing adequate levelsof insulin, the body has developed resistance to the action of the insulin. It is true to say that the understanding of diabetes and its treatment have changed dramatically over the last few years.

The pathway to a person with diabetes finally developing sufficient complications in order to warrant an amputation is fairly complex. Diabetes causes two major problems:

• Neuropathy.
• Peripheral Vascular Disease.

In most cases it is a combination of neuropathy and vascular disease (neuroischaemia) that ultimately leads to the amputation. Neuropathy often occurs in people who have had diabetes for a significant number of years (probably more than 10 years). Neuropathy leads to a loss of pain sensation initially over the toes and later spreading up the leg. In severe cases the loss of sensation has been seen to extend above the knees. In addition to the loss of sensation, the foot develops certain deformities leading to arching of the mid foot, curling of the toes and splaying of the foot causing it to widen. These changes cause high pressure areas when walking, particularly under the ball of the foot.

Peripheral vascular disease that occurs in diabetes is not dissimilar to the peripheral vascular disease that occurs in the person without diabetes. However it tends to arise more distally affecting the smaller vessels and thus the digits of the toes . The following factors have been implicated in leading to amputation in the person with diabetes:

Genetic Factors: See above

Poor Diabetes Control: For people with type I diabetes (dependent on insulin), the DCCT trial was a turning point. Similarly for type II diabetes (which is dependent on insulin) the UK PDS trial was extremely significant. Both the DCCT and the UK PDS trial was extremely significant. Both the DCCT and the UK PDS trial showed that close and accurate monitoring of blood glucose levels for 24 hours a day would very significantly reduce the complications of diabetes such as retinopathy (involvement to the eyes) nephropathy (involvement of the kidneys), high blood pressure, neuropathy and vascular disease.

There is now considerable research and investment into finding oral drugs and improved methods of delivery of insulin that will allow very close and detailed control of insulin during the entire day. The importance of good dietetic control should not be overlooked.

Control of High Blood Pressure: This can have a major affect in reducing the level vascular disease and kidney disease and in diabetics should be aggressive. Control of raised blood cholesterol: (similar to vascular disease).

Foot care: Education of the individual in the care of their feet. Preventing trauma either multiple small incidents of trauma or even major trauma is extremely important. The commonest cause of trauma to the insensate diabetic foot is improper shoe wear. Many people with diabetes will try to wear ‘off the shelf’ shoes and will not perceive that they are ill fitting or causing abrasions and soreness to the foot. Wearing such shoes for more than an hour and half will almost inevitably result in a pressure area over the toe.

Getting advice from a podiatrist (chiropodist) together with education in looking after your foot is of the greatest importance. People with diabetes are entitled to free podiatry and should be encouraged to build up a long term relationship with their podiatrist. We would advise that they seek regular podiatry care where the foot is inspected and advice given as to shoe wear. As regards footwear, it is our experience that modern good quality trainers may be beautifully designed and can be greatly helpful to many people with diabetes. Unfortunately, for ladies in particular, modern elegant footwear is not designed for comfort and can be very unsafe to the diabetic foot.

The diabetic foot can also develop extremely dry skin due to a neuropathy. The patient can help with regular washing of the feet, inspection for trauma and applying liberal amounts of a moisturiser such as E45 or other moisturiser. Diabetic amputees are at risk of losing their 2nd limb and MUST take all possible care of their good leg. Table 1 shows the written instructions given to all vascular amputees attending Stanmore DSC.

Other factors are common to patients with peripheral vascular disease i.e. smoking, cholesterol.

Exercise: People with diabetes who are under the care of podiatrists and have appropriate shoes should try and maximise their level of exercise. However this should be done with care and with continued inspection of the foot in order to ensure no damage has occurred.

Trauma

Trauma, by its very ‘accidental’ nature cannot always be avoided. However, it is worth highlighting that all sensible precautions should be taken in high risk situations and activities, be they at work or leisure.

With modern techniques and instrumentation, orthopaedic surgeons have managed to save many limbs which a few decades ago would almost certainly have been lost. These days only the occasional amputation is carried out as an emergency. Most damaged limbs can be splinted to allow the patient to be prepared physically and psychologically prior to amputation surgery. This does occasionally present a problem, as some patients would probably have had a better quality of life with an earlier amputation and appropriate prosthesis rather than continue persevering with a painful, unhealed, malunited, functionless limb. Repeated surgery and delay in amputation often adversely affects total rehabilitation.We would recommend a pre-amputation consultation with a prosthetic rehabilitation team.

Tumour

Amputation for tumour is almost always a last resort and in these circumstances life saving. Early diagnosis is paramount for successful treatment and we would recommend individuals seek timely advice for any suspicious lumps.

Other Causes

These causes include infection, poor function or complications due to congenital limb deformities or rare disease. Amputation is almost always a treatment ‘option’ and once again, we would advise a pre-amputation consultation.

In conclusion, we would re-iterate that while it is important to work towards preventing amputations, it can be life saving and can for some, improve the quality of life.

Authors:

Dr Ernest vanRoss, MCh,FRCP,FRCS, Consultant in Rehabilitation Medicine, Withington Hospital DSC, Manchester Dr. Rajiv Hanspal, MBBS,FRCP,FRCS, Consultant in Rehabilitation Medicine, Stanmore DSC, Stanmore.