Carotid Endarterectomy

What is carotid endarterectomy?

As people age, they can suffer from the narrowing of the carotid arteries. These are the major arteries which supply blood to the brain, head and neck. The narrowing of the arteries is caused by a build-up of plaque (deposits of fatty substances). This plaque may cause turbulent blood flow and material breaking off can lodge in the brain causing either transient symptoms or a stroke. Those with transient symptoms have the highest risk of stroke in the period immediately following the onset of symptoms.

The risk of stroke can be reduced if surgery is performed quickly following the onset of symptoms. For patients with a narrowing of an artery between 50% and 99%, it is recommended that surgery to remove the plaque, a carotid endarterectomy, is performed within two weeks.

What information is being published on carotid endarterectomy?

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 trust submitted compared to the total they carried out according to national data sources.

The average number of days between initial symptom and procedure is shown in the second row. The numbers in brackets are the typical number of days a patient will have to wait. The current NICE guideline recommends 14 days as the target time from symptom to operation in order to minimise the chance of a high risk patient developing a stroke.

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

The final piece of information published is the proportion patients who were alive and did not suffer a post-operative stroke within 30 days of the procedure (called stroke free survival). This provides a measure of the safety of the procedure, and is a fundamental aspect of care. However, it only reflects one part of the spectrum of outcomes that are important to patients and, in time, we expect to report on a wider set of outcomes for patients.

The information on this website was published in November 2021.

What data is being used to produce this outcome information?

The rates of stroke free survival within 30 days of the carotid endarterectomy are based on three years of data, and include patients who were admitted to hospital and had their surgery between 1 January 2018 and 31 December 2020.

How are the data analysed?

The 30-day stroke free survival rate is calculated by identifying all patients who were alive and did not suffer a stroke within 30 days of the carotid endarterectomy and dividing this number by all patients operated on by that particular surgeon or at that NHS trust.

The results have been risk adjusted for patient case-mix to ensure that NHS trust 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 trusts 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 carotid endarterectomy, we used a risk model that contained the patient factors: age at operation, sex, whether the patient had diabetes, creatinine, ASA grade, the pre-operative Rankin score and national COVID-19 admission rates.