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Vascular services treat people who have circulation problems. These problems include poor circulation in the legs (peripheral arterial disease), bleeding from burst blood vessels in the abdomen (aortic aneurysm), disease in the neck (carotid) arteries that may cause strokes, and varicose veins. Advances in treatment have led to many vascular services being moved into larger centres (so they are more centralised) to improve the quality of care.

This research found variation in the uptake of new technologies and practice, and in the quality of vascular care across England. It confirmed that delivering major vascular procedures in larger centres improves the quality and efficiency of services. 1 in 5 hospitals carries out fewer vascular procedures than nationally recommended thresholds. Increasing these thresholds could further improve clinical outcomes and efficiency. At the same time, many services that could be provided locally have been centralised.

The researchers measured the strength of people’s preferences for less invasive treatments and local services. They looked at the trade-offs people would accept for better clinical outcomes. The researchers suggest that better coordination between major vascular centres and local hospitals would allow some services to be provided locally. Major vascular procedures would be carried out at central sites, while investigations, minor procedures and rehabilitation would take place locally.

To help plan how services are organised, and evaluate the impact on the quality of care, the researchers developed two tools. One is a web-based outcome measure that gathers data from patients on their symptoms and quality of life before and after treatment. The second enables managers to look at the effects of different ways of organising services. The tool allows them to predict the costs, resource implications and impact on quality, of changes they make.

What’s the issue?

Vascular services treat people with circulation problems, including peripheral arterial disease, abdominal aortic aneurysm and narrowing of the carotid arteries that may cause strokes.  These conditions can be life-threatening or lead to limb amputation. They often require emergency treatment, involving complex and specialised facilities and skills.

Over the last few decades, new treatments for vascular disease and changes to the way clinicians are trained and work, has resulted in services being delivered in fewer, larger centres. Centralisation of services is intended to improve the quality of care and make the best use of scarce specialist skills.

The drive to improve services is ongoing. Researchers therefore wanted to find out what elements of the services are most important to the people using them. They also looked at the impact of service changes on costs and outcomes. They wanted to find out how services might be best organised to provide better care, and meet people’s preferences for where they are treated and what methods are used. They also wanted to develop tools to help plan and assess the impact of service change.

What’s new?

Analysis of national hospital data showed considerable variation in practice, with variable uptake of new technologies, such as the use of minimally invasive treatment. Current guidance states that vascular centres should carry out a minimum of 60 aortic aneurysm procedures per year. The evidence from this research confirms that centres carrying out more procedures get better results. It found that further quality and efficiency gains may be achieved if the threshold was increased to 100 cases per year.

The team reviewed all available outcome measures for vascular disease, and developed a new web-based tool. It records data on people’s clinical condition, and their outcome after treatment by a vascular service. The tool can be used to monitor individuals’ progress or to evaluate the service. It has been extensively tested to ensure it is robust.

Next, the team generated a computer model for hospitals that are planning to change how they deliver services. The model predicts the future service costs, workload, and clinical outcomes. The model was validated through comparison of simulated and actual data.

Last, the team investigated people’s preferences around two key issues identified as important to the public when considering service change. The first was the travelling distance to vascular services. The second was the choice between minimally invasive and open surgery.

Members of the public were asked to complete questionnaires which presented different treatment scenarios. From 821 responses, the researchers found that people preferred less invasive treatments and more local services. However, people were prepared to accept services being further away if they had significantly better clinical outcomes, and the researchers quantified the strength of this preference.

Why is this important?

Many (1 in 5) hospitals are carrying out fewer vascular procedures than the nationally recommended threshold. This may result in poorer clinical outcomes and efficiency. This research demonstrates that patients would have better clinical outcomes if services were centralised further. Centralised services are also more cost effective.

The research also showed that patients prefer local services, unless there is a meaningful difference in outcomes. Some services such as investigations, minor surgery and rehabilitation could take place locally. However, these services have often been moved to the larger centres when major surgery has been centralised.

This project provides managers with the tools to plan the necessary service changes, and to demonstrate the benefit in clinical outcomes.

What’s next?

The researchers hope that the tools they have developed will be used in practice, and then refined to best meet clinical and managerial needs.

They would also like to see more research into why some areas are unable to implement changes to services. This project provides evidence that raising the threshold for centres to 100 aneurysms a year may be beneficial. But this should not mean moving services that could safely be provided locally.

The team hopes more areas will consider better integration of local and centralised services. This would enable complex procedures to be carried out centrally, while those services that can be provided safely are delivered locally. Finally, they would like more detailed data to be collected about the aspects of vascular outcomes that are most relevant to patients. This would allow greater scrutiny of local clinical practice and outcomes.

You may be interested to read

This Alert was based on: Michaels J, and others. Configuration of vascular services: a multiple methods research programme. Programme Grants Applied Research 2021;9:5.

The online model for hospitals planning change is complex. Please contact the authors directly for further detailed explanation.

Advice from the NHS website on preventing vascular diseases

A statement from the Vascular Society: The Provision of Services for Patients with Vascular Disease.

The Circulation Foundation website, which has information for patients about vascular disease

The Vascular Society has information for patients and documents such as guidance about the provision of vascular services.

Funding: This project was funded by the NIHR Programme Grants for Applied Research programme.

Conflicts of Interest: Stephen Radley is a director and shareholder (unsalaried) of ePAQ (ePAQ Systems Ltd, Sheffield, UK), an NHS spin-off technology company (majority shareholder Sheffield Teaching Hospitals NHS Trust).

Disclaimer: NIHR Alerts are not a substitute for professional medical advice. They provide information about research which is funded or supported by the NIHR. Please note that views expressed in NIHR Alerts are those of the author(s) and reviewer(s) at the time of publication. They do not necessarily reflect the views of the NHS, the NIHR or the Department of Health and Social Care.

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Study author

Reconfiguring services is a complex and quite politicised area, and any withdrawal of local services is often controversial. Even so, we were surprised to find so much variation in practice and outcomes. There are evidence-based NHS guidelines recommending that each centre should do at least 60 aortic aneurysm procedures and 40 carotid procedures, while patients have strong preferences for those services which can be done safely, to be provided locally.

Our main findings and models of service reconfiguration are most relevant to policy makers. Outcome measures, patient preference work and evidence around service provision are relevant to the public, patients, and healthcare professionals.

Jonathan Michaels, Researcher, University of Sheffield

Vascular Society

“It is reassuring that the reconfiguration of Vascular Services in England that has occurred over the last 15 years has led to improved patient outcomes and is both clinically and cost-effective. Vascular service reconfiguration was driven both by evidence of a volume outcome relationship for survival after aortic aneurysm surgery and by the workforce considerations of providing safe and sustainable 24/7 vascular surgery and interventional radiology on call rotas.

The Vascular Society of Great Britain and Ireland has supported centralisation of services with the 3-yearly publication of “The Provision of Services for People with Vascular Disease”, which was last updated in 2021. However, we are also mindful that people want local services and that vascular networks deliver outpatient clinics, diagnostic services, surveillance, and minor interventions locally for patients in addition to performing major arterial procedures centrally.

Centralisation of services is not without some risk: Contemporary data has shown that an initial presentation to a non-arterial hospital with critical limb threatening ischaemia, results in significantly longer time to treatment and poorer outcomes, than for patients who presented directly to the centre.”

Jonathan Boyle, President of the Vascular Society and Marcus Brooks, Honorary Secretary of the Vascular Society


“The results suggest there is considerable opportunity for more integrated services in which major vascular procedures are carried out at a single site. Collaborative working arrangements will allow people having minor procedures, investigations or rehabilitation services, to be managed more locally.

The electronic Personal Assessment Questionnaire – Vascular can effectively collect patients’ reports of the process of care, along with their physical and psychological symptoms, social wellbeing, and the financial impact of their treatment. Policymakers and administrators can use this information in service evaluation. It might also help researchers look into links between vascular disease and other conditions. However, further work is required to evaluate the usefulness of the tool in wider clinical practice.

Navaraj Perumalsamy, Former Principal, Annai Fathima College of Arts and Science, Madurai, India


This thorough piece of work confirms the direction of travel for vascular services over the last 20 years. These data suggest that there could be further gains from concentrating aortic services into units doing large numbers of cases per year. This might be of interest to NHS commissioners who are still trying to deal with units that have not reconfigured and could be improved. Some of the findings are known. Patients prefer minimally invasive procedures and prefer local services where possible. But they accept that they may need to travel for complex interventions. Better outcomes from units with higher volumes of a procedure have been seen in many surgical specialties.

Robert Sayers, Professor of Vascular Surgery, University of Leicester
Robert Sayers chairs the Vascular Clinical Reference Group as part of NHSEI Specialised Commissioning 

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