Numerical Studies of Polymer Materials with Potential for Use in Coronary Stent-Grafts

This study uses computer modeling to assess the potential of using certain biocompatible polymer materials in coronary stent-grafts. Numerical experiments were carried out to assess mechanical properties of samples of polymer materials: hydrogels based on polyvinyl alcohol or polylactide–polycaprolactone copolymer. The studies showed that when the stent-graft membrane was free to move, all the materials showed similar shortening, with changes in diameter of 7.21-7.63 mm from the initial 20 mm (36.05-36.6%). This was accompanied by thinning of the component by 34-37%. When the membrane was fully fixed to prevent shortening, the decrease in thickness was greater – by 53-61% – and was accompanied by a significant increase in stress (for one polylactide–polycaprolactone copolymer it reached 44.37 MPa, which is close to the tensile strength of the material, 47.07 MPa). These results show that three of the studied materials have potential for use in coronary stent-grafts: two modified hydrogels based on polyvinyl alcohol and a polylactide–polycaprolactone copolymer.