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

Abstract

Using color duplex ultrasound (CDU) surveillance of autogenous infrainguinal 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 predicting significant stenosis mandating revision. At the proximal anastomosis, where significant vessel diameter differences and turbulent flow exist, the validity of these criteria is less clear. Our purpose was to review our experience with proximal anastomotic abnormalities in a CDU surveillance protocol. Routine CDU surveillance for all infrainguinal bypass gratis consisted of evaluation in an accredited vascular laboratory at 1 month postoperatively, every 3 months for the first year, every 6 months in the second year, and annually thereafter. Grafts with a PSFV ratio of >3 at the proximal anastomosis on any CDU study were included in this review. From our results we conclude that currently accepted CDU criteria for graft-threatening stenosis may not be valid for abnormalities at the proximal anastomosis of infrainguinal grafts. Regression of these abnormalities is common. Better CDU criteria are needed for predicting not only severity of proximal anastomotic stenosis but also likelihood of graft thrombosis.

Remodeling in peripheral vein graft revisions: Serial study with three-dimensional ultrasound imaging

“…Changes in flow velocity can be particularly difficult to define in anastomoses and patched graft segments because of irregular geometry and complex blood flow patterns. 18,19 Spectral waveforms in dilated segments are characterized by disturbed flow resulting from eddies, and it is difficult to determine an appropriate Doppler measurement angle relative to the vessel walls. These factors lead to uncertainty in the identification of peak systolic flow velocity.…”

Long-term outcome of revised lower-extremity bypass grafts

“…Because the LEVGs in this series were constructed from reversed veins, lesions most frequently occurred in the proximal portion of the graft. Although there is general agreement that significant lesions detected within the graft warrant revision, recent reports have questioned the necessity of correcting proximal inflow 18 and proximal anastomotic 19 lesions. Lesions at these sites were not believed to negatively impact subsequent LEVG patency.…”

Estenose do enxerto de veia safena magna reversa em revascularização arterial infrainguinal

“…Some authors 22 demonstrated the stenoses located at that segment are poorly symptomatic, compared with those located at the bypass distal segments. Others debate the prognostic significance of stenosis located at the proximal anastomosis, as well as their repair benefit 23 . The increased flow velocity at the proximal anastomosis is frequently found on routine sonographic imaging and may not be related to the stenosis.…”