Follow-up of valves in saphenous vein bypass grafts with duplex ultrasonography

Purpose: The objectives of this study were to describe the venous valves an d determine their fate over time in reversed saphenous vein (RSV) and in si tu saphenous vein (ISV) bypass grafts with duplex ultrasonography. Methods: Sixty-four patients contributed 50 RSV and 19 ISV infrainguinal ve in grafts. Forty-two of the RSVs and 17 of the ISVs had valves or valve rem nants. The grafts and valves were studied serially with duplex ultrasonogra phy to document the location, characteristics, and changes with time. The v alve leaflets visualized by means of ultrasonic duplex scanning were descri bed as moving, frozen, remnant of a cusp, or "functioning." In addition, th e presence of a valve sinus and thickening of the wall at the site were doc umented. Grafts were studied at 1, 2, 3, 4, 6, 9, 12, and 18 months and the n annually. Results: In 42 RSV grafts (84%) and 17 ISV grafts (89.5%), 200 valves were identified. Only five of the 200 valves (2.5%) required intervention becaus e of a velocity ratio (VR) of 3.5 or greater. Eight (42.1%) of the 19 ISV g rafts needed 15 revisions, and 18 (36%) of the 50 RSV grafts required 30 re visions. The five revisions for a stenotic valve occurred only in RSV graft s. From the 30 revisions in the RSV grafts, only 16.7% (5 of 30) mere for a valve-related stenosis. The average follow-up period for a valve from the time of detection was 16.1 +/- 9.6 months. Ten of the 17 (58.8%) valve-asso ciated stenoses (VR > 2.5) showed a regression to a VR less than 2.0 within a mean time of 3.1 months (range, 1.5-4.5 months). A progression of the va lve-associated lesion from a VR less than 2.0 to a VR higher than 3.5 occur red in only one case within a period of 3.5 months. Conclusion: The described features of valves in saphenous vein grafts are c ommon and can be identified by means of duplex sonography. Only 16.7% of th e revisions in RSV grafts were performed because of a valve-related stenosi s, and none of the revisions in ISV grafts were performed because of a valv e lesion. Lesions associated with a valve may regress in time. No specific valve features could be identified as "high" risk for graft failure.