Abnormal duplex findings at the proximal anastomosis of infrainguinal bypass grafts: Does revision enhance patency?

Using color duplex ultrasound (CDU) surveillance of autogenous infrainguina l bypasses, a peak systolic flow velocity (PSFV) ratio of greater than 3 to 1 within the graft relative to adjacent PSFV has been accepted as predicti ng significant stenosis mandating revision. At the proximal anastomosis, wh ere significant vessel diameter differences and turbulent flow exist, the v alidity of these criteria is less clear. Our purpose was to review our expe rience with proximal anastomotic abnormalities in a CDU surveillance protoc ol. Routine CDU surveillance for all infrainguinal bypass gratis consisted of evaluation in an accredited vascular laboratory at 1 month postoperative ly, every 3 months for the first year, every 6 months in the second year, a nd annually thereafter. Grafts with a PSFV ratio of >3 at the proximal anas tomosis on any CDU study were included in this review. From our results we conclude that currently accepted CDU criteria for graft-threatening stenosi s may not be valid for abnormalities at the proximal anastomosis of infrain guinal grafts. Regression of these abnormalities is common. Better CDU crit eria are needed for predicting not only severity of proximal anastomotic st enosis but also likelihood of graft thrombosis.