Venous grafts remain the most used conduits in coronary artery bypass grafting (CABG) but are highly susceptible to early failure due to ischemia-reperfusion injury, intimal hyperplasia, and accelerated atherosclerosis. Specialized preservation solutions such as DuraGraft and TiProtec aim to protect endothelial integrity during intraoperative storage; however, their long-term effects on venous graft adaptation remain unclear. In this study, saline, DuraGraft, and TiProtec were compared in a rat model of arterialized autologous jugular vein interposition grafting. Male Wistar rats were assigned to one of the three storage solutions or a Sham group with immediate implantation. Jugular veins were harvested, preserved for 2 h, and implanted into the infrarenal abdominal aorta using end-to-end microsurgical anastomoses. After 16 weeks, all grafts remained patent and exhibited pronounced arterial remodeling, including dilation, wall thickening, intimal hyperplasia, and loss of endothelium-dependent relaxation, while endothelium-independent relaxation was preserved. Although TiProtec-treated grafts showed slightly enhanced relaxation compared with saline-treated grafts, no preservation solution demonstrated a significant functional or structural advantage at 16 weeks. These findings suggest that long-term arterial loading is the dominant determinant of venous graft remodeling.