Recognition and surgical management of patent but hemodynamically failed arterial grafts.

During a five-year period, 34 patients had persistence or recurrence of abnormal hemodynamic measurements in limbs after arterial reconstruction depsite graft patency documented by arteriography. Initial operations included aortofemoral (four), femorofemoral (ten), femoropopliteal (18), and femorotibial (two) bypass. Immediate postoperative hemodynamic failure was documented in seven patients by a mean ankle/brachial systolic pressure index increase of only 0.05 +/- 0.04 following the initial reconstruction. The remaining 27 patients had delayed hemodynamic failure; mean increase in ankle pressure was only 0.06 +/- 0.05 from the preoperative period until time of detection of failure (average duration 2.5 years). In all 34 patients, arteriography demonstrated patency of the initial graft. In conjunction with the vascular laboratory examination, arteriography identified the cause of hemodynamic failure to be inadequate inflow in 10 patients, poor outflow in 16, combined inflow and outflow obstruction in one, and graft stenosis in seven. Unrecognized stenosis in areas proximal (two patients) and distal (three patients) to the bypass emphasized the importance of complete biplanar arteriography before initial operation. Reoperation was successful in correcting hemodynamic failure in 26 patients (76.5%) with a mean increase in ankle index of 0.41 +/- 0.15. Operation was technically not feasible in four patients and was not performed in another four patients because of concomitant medical problems. In two of these patients, progression to graft thrombosis was documented. The results of this study suggest that early objective recognition of an anatomically patent but hemodynamically failed graft is possible by frequent noninvasive testing. Prompt investigation by arteriography defines the cause and location of failure, and reoperation restores normal limb hemodynamics. Most important, reoperation permits salvage of the majority of these patent grafts prior to ultimate failure from thrombosis.