Current Status and Future Prospects of Small-Diameter Artificial Blood Vessels

Small-diameter vascular grafts (SDVGs, ≤6 mm) face significant barriers in vascular reconstruction due to poor long-term patency stemming from thrombosis, intimal hyperplasia, and mechanical mismatch. Increasing rates of cardiovascular disease and limited autologous vessel supply underscore the urgent need for functional SDVGs. This review discusses the critical failure mechanisms of SDVGs and recent material-based advances—hydrophilic modifications, charge control, micro- and nano-engineering, antimicrobial and anti-inflammatory treatments, and controlled bioactive release (e.g., heparin, nitric oxide, t-PA). It details progress in cellular and tissue engineering for rapid endothelialization, smooth muscle regeneration, and mechanical durability. The review also highlights emerging gene engineering, the use of bioactive peptides, and molecular pathway strategies for physiological antithrombotic restoration. Finally, it outlines future directions, including smart materials, accelerated endothelialization, advanced manufacturing (3D printing, multilayer electrospinning), multifunctional composites, and clinical translation. Overall, SDVG research is shifting toward active, regenerative vascular substitutes with improved clinical prospects.