The structural changes in the venous wall in addition to the increased expression of MMP-2, MMP-9 and MMP-13 in VA compared to NSV and VV suggests a possible causal role for these MMPs in their pathogenesis.

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To evaluate prospectively 42 lower extremity arm vein bypasses with use of color duplex surveillance (CDS). Methods: Twenty-seven bypasses (64%) were to tibial arteries, 12 (29%) were to popliteal arteries, and three (7%) were to superficial femoral arteries. Twelve bypasses were composed of a single arm vein segment, and 30 were composite vein bypasses. Bypasses were evaluated with CDS and ankle-brachial indexes before the patients were discharged from the hospital, at 1 month, and then every 3 months during the first year; every 6 months during the second year; and annually thereafter. The median follow-up period was 17 months, and the median number of scans performed per bypass was seven. Each examination conSisted of a scan of the entire bypass with velocity measurements taken routinely at the proximal and distal anastomoses and at a proximal and distal bypass segment in addition to any high-velocity area identified on the CDS. Peak systolic velocity greater than three times that of an adjacent graft segment or peak systolic velocity less than 45 cm/sec throughout the vein conduit were indications for arteriography. Results: Thirteen arteriograms were performed because of abnormal duplex findings on surveillance. Extension or interposition vein grafts (9), vein patch angioplasty (1), or inflow procedures (3) were used to maintain secondary patency. The 24-month primary and secondary patency rates were 46% and 85%, respectively. Three patients required amputation of a major extremity. Conclusions: Arm veins are satisfactory conduits for lower extremity revascularization. However, preocdusive lesions that require correction are commonly found on surveillance, especially when composite bypasses are required. Vein bypass surveillance with CDS allows identification and appropriate correction of preocdusive lesions.