Study of mechanical behavior of additive manufacturing bioresorbable polymeric stents models

Del Monaco ADM, Del Monaco MI, Andrade AJP, Malmonge SM

Stents are devices with important applications in cardiology. They can be used in different cases, as coronary artery disease, peripheral interventions, such as the iliac and carotid arteries, and in very specific applications, as congenital heart disease in aortic coarctation. Studies point to biodegradability of stents as one of the main properties of future generations of these devices. The development of stents made from fully bioresorbable polymeric materials, with appropriate mechanical properties for different applications, is considered an interesting point to be studied. Thus, the objective of this project was to study models of bioabsorbable stents of poly (-L-lactic acid) (PLLA), poly (-L-D lactic acid) (PLDLA) produced by additive manufacturing. The mechanical performances were evaluated by stress and tensile strain tests of different blends compositions of these materials. A heat-shock shape memory allocation process and a flexible tube model for simulating implant conditions were developed. PLLA has higher mechanical strength and hardness, while PLDLA is more elastic. Thus, it was possible to study the adequacy of the composition and mechanical properties of the prototypes for each different situation studied (coronary, peripheral and Aortic coarctation implants).