Pain after amputation: clinical trial of a possible new treatment

This research was completed on 30 November 2011

Published on 30 January 2009

What's the problem and who does it affect?

Living in pain

Each year in the UK, approximately 5,000 people have their leg amputated and are referred to a prosthetics centre.¹ After surgery, people can suffer severe pain.

So-called ‘stump pain’ comes from the wound site itself. Up to 70% of people also suffer ‘phantom limb pain’, which feels like it is coming from part of the leg that has actually been amputated.^2-5 They may, for example, experience a burning or cramping pain in their foot, even though their foot is no longer there.

Troublesome phantom limb sensations also occur. People may experience sensations such as itching, movement, pressure and sensitivities to heat and cold that feel like they come from the missing limb.

Phantom limb pain is particularly difficult to treat, with many sufferers relying on strong pain killers, such as morphine. These are not always successful and often cause significant side effects.

Sadly, some people find their pain persists over the long term. Although a good recovery is possible after amputation, pain complicates rehabilitation, making it more difficult to use prosthetic limbs and regain mobility, limiting independence and the ability to work. Chronic pain can also cause depression, sleep deprivation, a reluctance to socialise and difficulties with everyday activities.

What is the project trying to achieve?

Clinical trial of a new technique

The researchers are performing a clinical trial of a new technique to find out how it affects pain after amputation. This technique involves placing a small tube, called a catheter, directly alongside the major nerve of the leg (the sciatic nerve) at the time of surgery and infusing a local anaesthetic, called levobupivacaine, for 4 days.

They are assessing effects on stump pain, phantom limb pain and phantom limb sensations over the following year. They are also assessing morphine requirements immediately after surgery and long-term effects on mood, physical disability and quality of life.

Around 70 people are volunteering to take part in the trial. They all have diseased arteries in the leg, a common reason for amputation, particularly in smokers and people with diabetes. Half of the volunteers will receive the study drug and half will receive a placebo, or dummy drug. The surgeons, nurses and volunteers will not be told who is receiving which treatment.

What are the researchers' credentials?

The project leader, Dr Jonathan Thompson, and the University Department of Anaesthesia, Critical Care and Pain Management, have a long and well-established track record of researching what causes pain and how to manage it.

Dr Thompson is Senior Lecturer in Anaesthesia & Critical Care Medicine, leading a study team that includes anaesthetists, nurses, pain specialists and surgeons. Dr Thompson is the current Chairman of the Vascular Anaesthesia Society of Great Britain & Ireland, and has written several book chapters and many research papers on the management of people with vascular and cardiovascular disease.

Vascular disease refers to diseases of blood vessels, including atheroma (fatty deposits in the walls of arteries) or atherosclerosis (hardening of the arteries). These conditions are often related to smoking, high blood pressure, diabetes or high cholesterol, and as an anaesthetist Dr Thompson looks after patients needing surgery for these conditions.

Blockage or hardening of the arteries in the legs can reduce the blood supply to the feet and lower legs, causing pain on walking or in severe cases ulcers and gangrene. If simple treatments or surgery is ineffective, these patients may need amputation of the affected areas.

Dr Thompson’s team works within the University of Leicester and the University Hospitals of Leicester NHS Trust, which have a large and well established vascular unit.

Who stands to benefit from this research and how?

Relieving pain and improving mobility

The researchers believe the new technique that they are investigating has the potential to relieve pain, aid rehabilitation and improve quality of life for people who have had their leg amputated because of vascular disease. This clinical trial will reveal whether their technique does give these benefits.

If proved effective, it’s possible this technique could also be used in people who are undergoing amputations for other reasons, for example severe traumatic injuries or bone cancer.

An effective treatment that relieves pain could make a real difference to people who have had their leg amputated. Coping with pain can be exhausting. Freedom from pain could reduce people’s reliance on pain killers and hugely improve their well-being and quality of life.

Freedom from pain could also boost people’s chances of making a good recovery after surgery, cutting time spent in hospital. It could help people use prosthetic limbs more successfully, so improving mobility and aiding rehabilitation. This could improve people’s chances of living independently after surgery and of returning to work. What’s more, the increased independence and better body image that come with successful rehabilitation can significantly boost people’s self-esteem.

References

1. Information Services Division, NHS Scotland, on behalf of National Amputee Statistical Database (NASDAB). The Amputee Statistical Database for the United Kingdom. 2006/7. Edinburgh 2009. http://www.nasdab.co.uk/pdf.pl?file=nasdab/news/Final_2006_07.pdf
2. McCartney CJL, Charles DHM, Cooper GG, Chambers WA, Smith WCS. Pain and disability following lower limb amputation - a quantitative and qualitative study. Pain Clinic 1999; 11:293-300.
3. Jensen TS, Krebs B, Nieksen J, Rasmussen P. Phantom limb, phantom pain and stump pain in amputees during the first 6 months following limb amputation. Pain 1983; 17:243-56.
4. Nikolajsen L, Jensen TS. Phantom limb pain. Br J Anaesth 2001; 87: 107-16.
5. Lambert AW, Dashfield A, Cosgrove C, Wilkins DC, Walker AJ, Ashley S. Randomised prospective study comparing preoperative epidural and intraoperative perineural analgesia for the prevention of postoperative stump and phantom limb pain following major amputation. Reg Anesth Pain Med 2001; 26: 316-21