ONGOING VASCULAR LABORATORY SURVEILLANCE IS ESSENTIAL TO MAXIMIZE LONG-TERM IN-SITU SAPHENOUS-VEIN BYPASS PATENCY

Purpose: The purpose of this study was to assess the contribution of o ngoing graft surveillance to maximize long-term patency of lower limb in situ saphenous vein bypasses. Methods: From January 1981 to October 1994, 556 autogenous grafts were constructed in 499 patients. The dis tal anastomosis was at the poplitcal level in 207 (37%) and the tibial level in 349 (63%). All patients were enrolled in a prospective surve illance protocol to identify lesions that compromise graft patency and were evaluated at 1 day, 1 week, 6 weeks, and 3 months. Surveillance studies were then obtained every 3 months for the first 2 postoperativ e years and every 6 months thereafter. Results: Four-hundred-fifty abn ormalities were detected in 236 grafts. The median interval from the i nitial procedure to detection of an abnormality was 12 months (range 0 to 113 months) and varied with the location of the defect. Later in t he life of the graft, progression of atherosclerotic disease manifeste d as inflow obstruction at a median of 15 months, and outflow disease threatened the graft at a median of 29 months (r = 0.0003). Of the 450 surveillance abnormalities, 294 (65%) occurred within the first 2 yea rs after operation, and 156 (35%) developed more than 2 years after op eration. Of the 236 grafts that developed surveillance abnormalities, 50 (21%) developed the initial defect more than 2 years after the init ial bypass procedure. Eleven percent of grafts remaining free of abnor mality after 2 years went on to fail. Sixty-seven interventions were p erformed on 62 extremities after 24 months, with 30 involving previous ly unrevised grafts. Conclusions: Because lesions amenable to revision continue to develop years after vein bypass construction, perpetual s urveillance is required to ensure optimal rates of graft patency.