Biomechanical performance of natural and synthetic polymers in vascular surgery: a systematic review

In vascular surgery, polymer materials, both natural and synthetic, are widely used for grafting, stenting, and tissue engineering. In this review, we focus on evaluating materials science and engineering, including biocompatibility and clinical outcomes, to aid in biomedical decisions and material selection.
Following the PRISMA guidelines, we searched PubMed, ScienceDirect, Scopus, and the Persian databases Magiran and SID from 2000 to 2024. Inclusion criteria were the use of the specific terms “natural polymers” and “synthetic polymers” alongside “vascular surgery” and “biomechanical properties” and experimental and clinical studies with quantitative biomechanical data. We performed a qualitative assessment of all included studies.
From 2847 articles, 156 studies were selected, which included 89 experimental studies, 45 clinical trials, and 22 reviews. Natural polymers such as collagen and chitosan had better biocompatibility compared to that of synthetic polymers (92.3% vs 78.1%, p<0.001), although they had lower mechanical strength (28.9±6.3 vs 45.2±8.7 MPa, p<0.001). In comparison, synthetic polymers had high tensile strength, with PET at 72.4±12.1 MPa and PU showing 650-800% elongation. Clinically, natural polymers led to better 5-year success rates in natural coronary grafts (85.3% vs 78.9%), while synthetic polymers outperformed in peripheral grafts (89.2% vs 76.4% at 3 years). Natural polymers caused decreased inflammatory responses (8.7% vs 15.2%) but higher rates of complications due to degradation (12.4% vs 3.8%).
Synthetic polymers had higher mechanical strength, while natural polymers had better soft tissue integration and biocompatibility. There is additional flexibility in the design with hybrid systems. Further studies of clinical outcomes are needed with smart polymers and uniform methods of testing.