Heterogeneous and dynamic lumen remodeling of the entire infrainguinal vein bypass grafts in patients.

ABSTRACT

OBJECTIVE: To examine the regional variation and temporal change in lumen size along the entire autogenous vein bypass graft used for treating arterial occlusive disease in lower extremity and to explore the factors associated with graft expansive or constrictive remodeling. METHODS: Patients were prospectively scanned using contrast-enhanced computed tomography at 1 week and 1, 6, and 12 months postoperatively to obtain lumen cross-sectional areas at 1-mm intervals along the entire grafts. Graft lumen remodeling characteristics and the associated demographic and clinical factors were examined. RESULTS: Fifty-six patients with at least two consecutive computed tomography scans were analyzed. Patients with a composite or longer graft, or with diabetes, had a larger lumen cross-sectional area variation along the graft. The mean lumen cross-sectional areas of all the grafts demonstrated no significant changes through 12 months. However, individually, graft remodeling was time dependent and there was a more dramatic change in lumen cross-sectional area within the first postoperative month. At 12 months, a near equal distribution between expansive and constrictive grafts existed. A negative relation between the initial lumen diameters and the subsequent lumen diameter changes was observed. Eleven grafts failed within 12 months; failed and patent grafts had similar mean lumen cross-sectional areas at all four time points, but failed grafts had a larger maximal local cross-sectional area reduction from 1 week to 1 month (58.0 ± 6.7% vs 38.1 ± 3.1%, mean ± standard error of the mean, failed vs patent, P = .004). Black patients had a smaller mean lumen cross-sectional area than white patients at all four time points and also had a higher early percent mean area reduction (-20.5 ± 6.3% vs -1.0 ± 3.7%, black vs white, P = .018). Cilostazol use was associated with early expansive graft remodeling. CONCLUSIONS: Vein grafts remodel heterogeneously and dynamically. Remodeling is associated with initial graft lumen size, race, and cilostazol use. It is found that remodeling that produces some critical minimum area or maximal percent reduction during the first postoperative month may predispose to vein graft failure. These findings offer insight into further investigation to examine the underlying mechanisms and opportunities to improve graft remodeling and durability.