Purpose: In this study we assessed the costs and clinical outcomes of duplex scan surveillance during the first year after infrainguinal autologous vein bypass grafting surgery and compared duplex scan surveillance, ankle-brachial index surveillance, and clinical follow-up.
Methods: In a clinical study, 293 patients (mean age, 70.1 years; 58.7% men) with peripheral arterial disease were observed in a duplex scan surveillance program after infrainguinal autologous vein bypass grafting surgery. Costs were calculated from the health care perspective for surveillance and subsequent interventions from 30 days to 1 year postoperatively. All costs are presented in 1995 US dollars per patient. In a simulation model, we estimated the costs and amputations of duplex scan surveillance, ankle-brachial index surveillance, and clinical follow-up conditional on the indication for surgery. The main outcome measure was the incremental cost per major amputation per patient avoided during the first postoperative year.
Results: Duplex scan surveillance was the least expensive ($2823) and resulted in the fewest major amputations (17 per 1000 patients examined), compared with ankle-brachial index surveillance ($5411 and 77 amputations per 1000 patients) and clinical follow-up ($5072 and 77 amputations per 1000 patients). In patients treated for critical limb ischemia, duplex scan surveillance was the least expensive ($2974) and resulted in the fewest major amputations (19 per 1000 patients). Under all surveillance programs, 13 major amputations per 1000 patients treated for intermittent claudication were performed, and clinical follow-up had the lowest costs ($1577). In a sensitivity analysis that assumed that duplex scan surveillance could have avoided six major amputations per 1000 patients treated for intermittent claudication compared with the other programs, duplex scan surveillance had an incremental cost of $80,708 per major amputation per patient avoided compared with clinical follow-up.
Conclusion: Duplex scan surveillance is highly effective for patients treated for critical limb ischemia, leading to a reduction of major amputations and consequently to a reduction in costs compared with other surveillance programs. In patients treated for intermittent claudication, the evidence supporting duplex scan surveillance is less firm, but if duplex scan can avoid six major amputations per 1000 patients examined, the incremental costs are justified.