Vascular viewpoint

Abstract

Question: Is duplex scanning superior to clinical vein graft surveillance with respect to amputation rates, quality of life, and cost following femoropopliteal or femorocrural vein bypass graft? Population: Between 1998 and 2001, patients from 29 centers in the UK and Europe who had a patent vein graft 30 days following femoropopliteal or femorocrural vein bypass surgery for critical ischemia, claudication or symptomatic popliteal aneurysms were recruited for the study. Methods and results: There were 592 patients included in this multicenter randomized controlled trial. Patients with patent vein grafts at 30 days were randomized to receive or not receive duplex surveillance in addition to clinical examinations and ankle-brachial indices at 6 weeks (time of recruitment), and 3, 6, 9, 12 and 18 months. Stenoses within grafts were defined as slow peak systolic velocity (<45 cm/s), or a ratio of peak systolic velocity in an area of stenosis to any other area within 2 cm of >2. The primary endpoints were time to amputation and time to vascular mortality (MI, CHF, arrhythmia or CVA). Secondary outcomes included graft patency (whether primary or secondary, assisted or unassisted), cost, and quality of life as measured by SF-36 and EuroQol. The primary endpoints were analyzed according to an intention-to-treat analysis using Cox-regression and Kaplan-Meier life tables, while secondary outcomes were analyzed by the Mann-Whitney test and a t-test. Approximately 11% of patients died during the study, while 12% withdrew (45% of which were due to amputations). There were significantly more diagnostic interventions in the clinical follow-up group (31% vs 22%, P = 0.01). Between the clinical follow-up and duplex groups, there was no difference in amputation rate (7% vs 7%) or vascular death rate (3% vs 4%). A greater proportion of patients in the clinical follow-up group had a stenosis in the graft identified at the end of the study (19% vs 12%, p = 0.04). There were no differences in Kaplan-Meier estimates of primary, primary assisted and secondary patency rates between the two groups at 18 months. No differences in quality of life as measured by SF-36 or EuroQol were detected between the two groups. The cost per patient was greater in the duplex group (US$ 1537 vs US$ 2406, p = 0.002). Conclusion: The authors conclude that surveillance with duplex scanning following femoropopliteal or femorocrural bypass was more costly, but did not result in lower amputation rates.