Updated project metadata. Albeit vascular prostheses for the replacement of large arteries (e.g. aorta) are commercially available for decades, small-diameter vascular grafts (e.g., for coronary artery bypass graft surgery) still remain an unmet clinical need. Biostable polymers commonly used for the fabrication of aortic prostheses (e.g., poly(ethylene terephthalate) or expanded poly(tetrafluoroethylene)) have insufficient haemocompatibility to withstand thrombosis at low blood flow characteristic of small arteries (e.g., coronary artery). Hence, researchers endeavor to develop a biodegradable, tissue-engineered vascular graft (TEVG) to avoid the use of autologous blood vessels, such as saphenous vein or internal mammary artery, as conduits during the bypass surgery. Although a number of promising prototypes have been designed to date, none of them passed the pre-clinical trials successfully. Implantation into the ovine or porcine arteries is associated with thrombosis, neointimal hyperplasia, and aneurysms within one-year postoperation, precluding further clinical translation of TEVGs. Among the reasons of such impediment is that pathophysiology of TEVG implantation remains unclear and the molecular events occurring in the TEVG upon its implantation have not been properly investigated hitherto. Here, we for the first time performed a proteomic profiling of the TEVGs (n = 12) implanted into the ovine carotid arteries for one year and suffered from thrombosis to identify the signatures of TEVG failure in an unbiased manner. Contralateral intact ovine carotid arteries (n = 12) have been selected as a control group.