Revision of failing lower extremity bypass grafts

Color-duplex ultrasound (CDU) surveillance of arterial bypass grafts has been validated, but the natural history of "failing" grafts remains poorly defined. Our purpose was to compare failing grafts having prophylactic revision with those that did not.

Postoperative duplex surveillance was performed in an accredited vascular laboratory for all lower extremity bypass grafts performed at a single institution. Eighty-five infrainguinal grafts (57 vein, 21 polytetrafluoroethylene (PTFE), and 7 composite grafts) in 83 patients were identified as failing by accepted criteria. Twenty-five grafts were revised early (early), 20 grafts revised more than 2 months after the initial CDU-abnormality (late), and 40 grafts were not prophylactically revised (no revision) at any time.

The three groups were not different (P > 0.10) with regard to gender, age, level of bypass, type of conduit, location of stenoses, or timing of abnormality after surgery. No revision patients more frequently had diffuse low peak systolic flow velocity (PSV) as the CDU abnormality (P = 0.013). Cumulative primary patency was significantly better at 12 months (P = 0.028) in the no revision group (78.9%) compared with early grafts (43.1%) or late grafts (63.8%), and this difference remained significant when low PSV grafts were excluded from analysis. However, assisted primary patency, secondary patency, and limb salvage rates did not differ between the three groups (P > 0.10).

Our experience in this retrospective study contradicts other reports supporting the efficacy of prophylactic graft revision for grafts identified as failing by currently accepted CDU criteria. Refinement of CDU criteria to more accurately predict graft thrombosis is needed.