Should patients with infrainguinal arterial bypasses using autologous vein conduit undergo follow-up surveillance with duplex ultrasound?

This best evidence topic was investigated according to a structured format. The question asked was: should duplex ultrasound (DUS) scanning be a routine component of surveillance following infrainguinal arterial bypass using vein conduit? We performed a systematic literature search and identified 4 studies (3 randomised controlled trials and 1 meta-analysis) that provided the best evidence. The highest quality study was a multi-centre randomised controlled trial (n=594). At 18 months following surgery, it found no difference in patency rates, amputations, vascular mortality or mortality. However it achieved just over half of anticipated recruitment and thus was underpowered. The remaining two randomised controlled trials had smaller sample sizes and methodological weaknesses and found conflicting results. Lundell etal. (n=106) found improved primary assisted and secondary patency rates and fewer graft occlusions with a routine DUS policy. Ihlberg etal. (n=152) found no difference in primary assisted patency or amputations although secondary patency was improved. A meta-analysis of mostly observational data (n=6649) found fewer occlusions with routine DUS surveillance and no effect on amputations or mortality.Results are conflicting. The strongest evidence comes from the single high quality multi-centre trial. It appears as though routine DUS surveillance does not yield benefits in patient important outcomes. Further studies are needed.