Duplex ultrasound monitoring of arterial grafts: prospective evaluation in conjunction with ankle pressure indices after femorodistal bypass

Abstract

Duplex scanning and ankle brachial pressure indices have been used to objectively assess 94 femoro-distal bypass grafts 4-8 weeks postoperatively. Twenty grafts were occluded. Of the 74 patent grafts, three distinct groups could be identified on the basis of the non-invasive examination. Group 1. Patent grafts with no evidence of haemodynamically significant disease. Group 2. Patent grafts with localised disease. Group 3. Patent: haemodynamically failed grafts. Ankle brachial pressure indices alone could not differentiate between occluded grafts and grafts that were patent: haemodynamically failed (group 3), or adequately separate between grafts in groups 1 and 2. Duplex scanning when combined with pressure indices identified patent grafts "at risk" due to the presence of haemodynamically significant disease. Life table analysis demonstrated appreciable differences in event free survival between group 1 grafts and "at risk" grafts (groups 2 and 3). Duplex scanning is ideal for regular postoperative surveillance and complements the use of ankle brachial pressure indices in the follow-up of femoro-distal grafts.