Duplex scanning alone is not sufficient imaging before secondary procedures after lower extremity reversed vein bypass graft

Purpose: Duplex surveillance of lower extremity reversed vein bypass grafts (LERVG) is a means of identifying patients at risk for occlusion. The perc eived accuracy of duplex scan as a means of identifying stenoses has led ma ny surgeons to perform graft revision on the basis of duplex scan alone. Th is may result in missing additional lesions that are threatening patency. T o assess the role of duplex scan as the sole imaging method before revision of LERVGs, we reviewed consecutive patients undergoing revisions who under went preoperative arteriography after identification of duplex scan abnorma lities. Methods: Duplex scan results, operative reports, and preoperative arteriogr ams for patients undergoing LERVG revision from January 1990 to December 19 97 were reviewed. A standard duplex scan surveillance protocol was followed , and attempts were made to survey the entire graft, including inflow and o utflow Duplex scan results were compared with the results of preoperative a rteriograms and the operation performed to determine if all significant les ions were identified by means of duplex scan alone. Results: Two hundred five LERVG revisions were performed. The 5-year assist ed primary patency rate was 91%. In 119 cases (58%), arteriography did not contribute significantly to duplex scan findings. Arteriography significant ly contributed to operative planning in 86 cases (42%). In 38 cases (19%), only a low-flow state was identified by means of duplex scan, and a correct able stenosis was identified by means of arteriography. In 48 cases (23%), additional significant lesions corrected at operation were identified by me ans of arteriography. These included 26 inflow, 16 graft, and 8 outflow les ions. Arteriography was most useful as a means of determining the revision procedure performed when there were inflow lesions (P<.05) or when the prox imal anastomosis was to the profunda or superficial femoral arteries (P<.05 ). All frequently performed bypass graft configurations had some discrepanc y between arteriographic and duplex scan findings. Conclusion: Available data do not permit prediction of which LERVG are immu ne from missed lesions in a duplex scan surveillance protocol. This suggest s to us that arteriography is mandatory before LERVG revisions.