CXCL12 and aspiration pneumonitis: Grafts were explanted in 10 animals at 3 months (Bare n = 9; SDF1α n = 4; ePTFE n = 4) and 2 animals at 1 month (SDF1α n = 2; ePTFE n = 2) due to early termination as a result of suspected (aspiration) pneumonia.