The increasing specialisation and advances in technology allow more advanced complex treatments to be carried out, but require specialist staff and equipment. 

This, along with the high proportion of emergency cases dealt with by vascular services, have meant that it is no longer viable to provide a full range of services at all times in every hospital.

There is mounting evidence that better results are achieved by concentrating services in a smaller number of units with sufficient man-power and workload to provide full round the clock cover and experience in a range of specialist services.  

However there are a number of trade-offs that need to be made between the advantages of concentrating services in one place, access and availability of specialist services to the entire population and preferences relating to various aspects of service provision, such as location, accessibility and continuity of care.  

With the rapid development and changing services it is also necessary to have a way of consistently evaluating services to ensure they are of high quality.

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