Fresh Human Umbilical Cord Arteries as a Potential Source for Small-Diameter Vascular Grafts

The demand for small-diameter vascular grafts has been globally increased but still lacks optimal solutions in this category. This study evaluated the feasibility of utilizing human pretreated fresh and nondecellularized umbilical cord arteries (hUCAs) as vascular grafts without needing any immunosuppression process. A mixed lymphocyte reaction assay revealed that hUCAs did not induce lymphocyte proliferation or cytokine production. To assess the in vivo inflammatory response, hUCAs were buried in fatty tissue under the skin of the abdominal wall in the left and right iliac fossas of rats. The average sizes of the implanted hUCAs remained consistent at 30 days post implantation. To evaluate xenogeneic transplantation, hUCAs were grafted to the abdominal aorta below the kidney of Wister rats. Remarkably, all rats exhibited positive revascularization and perfusion, maintaining blood pressure values of around 110/70 mmHg. Doppler ultrasound consistently indicated good circulation, with the three separate echogenic layers corresponding to the three arterial wall layers throughout the assessment period. Grafted rats exhibited normal motor behavior, accompanied by positive responses to thermal and pain stimulation. Blood biochemical values and whole blood cell counts showed no significant differences between pre and post-transplantation. Histological analysis of the grafts revealed no calcification or thrombosis, and a mild chronic inflammatory response was presented. In conclusion, hUCAs maintained their structural and functional properties after transplantation in rats without immunosuppression. This highlights their potential as a source for allogeneic, readily accessible, small-diameter vascular grafts.