ABSTRACT
This chapter focuses on the histopathology of different poly-lactic acid (PLA) scaffolds including ABSORB, DESolve, Amaranth- Bioresorbable stents (BRSs), and ART-BRSs in animal models and the pathological changes that take place over time in relation to findings by intravascular imaging. Intravascular imaging modalities such as intravascular ultrasound (IVUS) and optical coherence tomography (OCT) are valuable tools for the assessment of coronary devices. The preclinical studies with ABSORB BVSs made of poly-L-lactic acid (PLLA) demonstrated comparable safety and efficacy compared to XIENCE in the normal porcine coronary arteries up to 48 months. Lumen enlargement is a unique feature of BRSs including both PLLA and Poly D, L-lactic acid (PDLLA), which was associated with inflammatory reactions during degradation. BRSs made of PDLLA showed faster degradation than that observed for BVSs PLLA. The preclinical studies suggest greater likelihood of thrombosis and delayed endothelialization as compared to contemporary metallic second generation drug eluting stents (DESs).
