Lower Limb Major Amputation

What is a major lower limb amputation?

Peripheral arterial disease (PAD) is a restriction of the blood flow in the lower-limb arteries. It can severely affect a patient’s quality of life. The disease can affect various sites in the legs, and produces symptoms that vary in their severity from pain in the legs during exercise to persistent ulcers, or gangrene.

It is possible to tread PAD with either a lower limb angioplasty/stent or a bypass. Despite these treatments, PAD can gradually progress in some patients to critical limb ischaemia for whom bypass is not a viable option. In these situations, patients will require amputation of the lower limb. About half of all these amputation procedures are below the ankle. Nonetheless, around 5000 patients in the UK require a major amputation each year, either above or below the knee.

What information is being published on lower limb amputation?

For each trust, we present the number of procedures they submitted to the NVR in the reporting period. The colour and symbol next to this number indicate the case ascertainment, which is the number of procedures the organisation submitted compared to the total they carried out according to national data sources.

The average number of days between assessment and procedure is shown in the second row. The numbers in brackets are the typical number of days a patient will have to wait. This is an important measure that was picked up in the NCEPOD report in 2014.

We also publish the average length of stay for patients undergoing a lower limb amputation procedure. The numbers in brackets are the typical range that patients will stay in hospital. The results for a particular trust can be seen in relation to the overall national length of stay.

The final row is the risk adjusted 30 day in-hospital survival rate for lower limb amputation for the trust. Again, this can be seen in comparison to the overall national survival rate.

The information on this website was published in November 2021.

What data is being used to produce the outcome information?

The results for lower limb bypass are based on procedures carried out between 1st January 2018 and 31st December 2020.

How are the data analysed?

The results have been risk adjusted for patient case-mix to ensure that NHS trusts that take on more difficult cases are not unfairly penalised. The reason for producing risk-adjusted outcomes is because the characteristics of patients treated by NHS trust will vary, and the outcome of care will be influenced by these characteristics – on average, outcomes are often worse for sicker patients. Risk adjustment allows us to take account of these factors.

For outcomes after lower limb amputation, we used a risk model that took account of the differences in patient populations within each organisation. Separate risk adjustment models were used for elective and emergency cases.
For elective cases, the rates were adjusted for age, ASA grade, chronic renal disease and national COVID-19 admission rates.
For emergency cases, the rates were adjusted for age, ASA grade, chronic renal disease, the level of amputation and national COVID-19 admission rates.