ABSTRACT
Vascular surgery is becoming dominated by and changing through the introduction of new
technologies. What evidence is needed before a new technology can be recommended for
routine clinical practice? The best level of evidence (level 1) is obtained from randomized
clinical trials. These may take several years to establish the trial, recruit the patients and then
follow them up for several years to establish whether the new technologies can provide durable
results, equivalent to, or better than, the previous gold standard. Since the time from idea of the
trial to results can be five years or more, such trials are best conducted early when the
technology is satisfactory, but before the technology has stabilized.
