Thirty-day vein remodeling is predictive of midterm graft patency after lower extremity bypass

ObjectiveSuccessful adaptation of a vein graft to an arterial environment is incompletely understood. We sought to investigate whether early vein graft remodeling is predictive of subsequent patency.MethodsA prospective longitudinal study was conducted of 67 patients undergoing lower extremity bypass with autogenous vein between February 2004 and April 2008. Preoperative blood samples were drawn for biomarkers. During the bypass operation, a 5-cm index segment of the graft was registered for serial lumen diameter measurements at 0, 1, 3, 6, 9, and 12 months using duplex ultrasound imaging. The imaging substudy analysis included patients with at least two ultrasound assessments.ResultsPatients (55% male) were a median age of 70 years (interquartile range [IQR], 59-76 years), 40% had diabetes mellitus, 49% had critical limb ischemia, 75% were taking a statin, and 91% were taking an antiplatelet medication. Median follow-up was 32 months (IQR, 15-47 months). The median baseline high-sensitivity C-reactive protein level (hsCRP) was 3.2 mg/L (IQR, 1.4-9.7 mg/L). The average intraoperative, postimplantation vein lumen diameter was 3.9±1.0 mm, increasing to 4.7±1.1 mm at 1 month, an average 24%±27% change per patient. By 3 months, the average lumen diameter was 5.1±1.6 mm, with little subsequent change observed to 12 months. Nonwhite race, baseline hsCRP ≥5 mg/L, statin use, and initial lumen diameter were significantly associated with early (0- to 1-month) vein remodeling in a multivariable regression model. The primary patency rate for the cohort was 60%±6.3% at 2 years. Initial lumen diameter of the index segment was not associated with primary patency, whereas larger lumen diameter achieved at 1 month (≥5.1 mm) was positively associated with primary patency (log-rank, P=.03). Early (30-day) remodeling behavior was used to divide patients into "poor remodelers" (<-5% lumen diameter change, n=6), "modest remodelers" (-5% to 25% change, n=29), and "robust remodelers" (>+25% change, n=30). Early remodeling category was significantly associated with primary patency rate at 2 years (log-rank, P=.02). A multivariable Cox proportional hazards model showed that modest remodelers (hazard ratio, 3.9; 95% confidence interval, 1.02-15; P=.04) and poor remodelers (hazard ratio, 13; 95% confidence interval; P=.008) had significantly higher hazard ratios for graft failure than robust early remodelers.ConclusionsEarly remodeling of the arterialized vein appears to predict midterm bypass graft patency. In addition to baseline diameter, race, inflammation, hsCRP, and statin use are associated with early adaptive remodeling, but the mechanisms for these observations are not understood

2003-2004 Research Honors Program Abstracts (for the College of Agriculture and Life Sciences Undergraduates)

Faculty in the College of Agriculture and Life Sciences at Cornell University mentor and guide undergraduate students who have chosen to pursue a research project and graduate with honors. These abstracts reflect the depth of their scholarship and intellectual ability. The research projects encompass work in animal science, biological science, entomology, landscape studies, natural resources, physical science, plant science, and social science